Title of Invention	V BELT TYPE CONTINUOUSLY VARIABLE TRANSMISSION .
Abstract	This invention relates to a V belt continuously variable transmission constituted by coupling a drive pulley 55, which is mounted on a crankshaft (input shaft) 28, and a driven pulley 56, which is mounted on a transmission shaft (output shaft) 47, with a V belt 57, when a driven side variable pulley half body 56b of the driven pulley 56 moves to a top time position where a winding diameter is minimized, a boss portion 63 of the driven side movable pulley half body 56b is brought into abutment against a spring bearing member 65, whereby the driven side movable pulley half body 56b is regulated to the top time position.

Title of Invention

V BELT TYPE CONTINUOUSLY VARIABLE TRANSMISSION .

Abstract

This invention relates to a V belt continuously variable transmission constituted by coupling a drive pulley 55, which is mounted on a crankshaft (input shaft) 28, and a driven pulley 56, which is mounted on a transmission shaft (output shaft) 47, with a V belt 57, when a driven side variable pulley half body 56b of the driven pulley 56 moves to a top time position where a winding diameter is minimized, a boss portion 63 of the driven side movable pulley half body 56b is brought into abutment against a spring bearing member 65, whereby the driven side movable pulley half body 56b is regulated to the top time position.

Full Text	V BELT TYPE CONTINUOUSLY VARIABLE TRANSMISSION Technical Field The present invention relates to aVbelt type continuously variable transmission which is constituted by coupling a drive pulley mounted on an input shaft, to which a torque is transmitted, and a driven pulley, which is mounted on an output shaft, with a V belt. Background Art For example, in a scooter type motorcycle, a V belt type continuously variable transmission may be adopted as a power transmission mechanism for transmitting an engine power to a rear wheel. In this type of V belt type continuously variable transmission, as shown in Figs. 13(a) and 13(b), a structure is in general use in which a drive pulley 103, which is mounted on a crankshaft (input shaft) 100 and has a driving side fixed pulley half body 101 and a driving side movable pulley half body 102, and a driven pulley 107, which is mounted on an output shaft 104 and has a driven side fixed pulley half body 105 and a driven side movable pulley half body 106, are coupled by a V belt 108. In the V belt type continuously variable transmission, a weight 109 moves the driving side movable pulley half body 102 to the side of the f ixed pulley half body 101 with a centrifugal force as an engine speed increases, and with this movement, the driven side movable pulley half body 106 of the driven pulley 107 moves in a direction apart from the fixed pulley half body 105 while compressing a spring 110. Consequently, a winding diameter of the drive pulley 103 increases and a winding diameter of the driven pulley 107 decreases, and a reduction gear ratio decreases to a reduction gear ratio at top time which is a minimum reduction gear ratio. In this case, it is a general practice to regulate a position in axial direction of the driving side movable pulley half body 102 to a top time position by regulating a position in radial direction of the weight 109 (e.g., see JP-A-8-178003, JP-A-8-178004). However, in the case in which a structure for regulating a reduction gear ratio at top time on a drive pulley side as in the above-mentioned conventional transmission is adopted, a winding diameter of the drive pulley is reduced by an amount of abrasion of a V belt and, in accordance with this, a winding diameter on a driven pulley side increases. Therefore, there is a problem in that a reduction gear ratio deviates to the side of a reduction gear ratio at low time from the reduction gear ratio at top time, and a maximum speed decreases. For example, as shown in Figs. 13(a) and 13(b), in the case in which an upper width dimension is reduced from L1 at the time when the V belt 108 is new to L1'due to abrasion of the V belt 108 when the motorcycle has traveled a certain distance D2 km, the winding diameter of the drive pulley 103 decreases from Rl in the top time position to Rl' by an amount of this abrasion and the winding diameter of the driven pulley 107 increases from R2 to R2', and the reduction gear ratio increases from R2/R1 to R2'/R1' . As a result, since a vehicle speed at top time with the same engine decreases, the V belt has to be replaced even if an abrasion loss is within a tolerance. Thus, improvement is required in realizing extension of a replacement period. The present invention has been devised in view of the above-mentioned circumstances, and it is an object of the present invention to provide a V belt type continuously variable transmission which can restrain deviation of a reduction gear ratio due to abrasion of a V belt to secure a vehicle speed at the same engine speed and can extend a replacement period of the V belt. Disclosure of the Invention An invention of claim 1 is a V belt type continuously variable transmission constituted by coupling a drive pulley of a winding diameter variable type, which is mounted on an input shaft, and a driven pulley of a winding diameter variable type, which is mounted on an output shaft parallel with the input shaft, with a V belt, characterized in that a reduction gear ratio at time when the drive pulley has a maximum winding diameter and the driven pulley has a minimum winding diameter decreases once and, then, increases in accordance with an increase in an operating time in a state in which the V belt type continuously variable transmission is operated using an identical V belt. An invention of claim 2 is a V belt type continuously variable transmission constituted by coupling a drive pulley of a winding diameter variable type, which is mounted on an input shaft, and a driven pulley of a winding diameter variable type, which is mounted on an output shaft parallel with the input shaft, with a V belt, characterized in that the number of rotations of the input shaft, which is necessary for obtaining the same number of output rotations, at time when the drive pulley has a maximum winding diameter and the driven pulley has a minimum winding diameter decreases once and, then, increases in accordance with an increase in an operating time in a state in which the V belt type continuously variable transmission is operated using an identical V belt. An invention in claim 3 is a V belt type continuously variable transmission according to claim 1 or 2, characterized in that the drive pulley comprises a driving side fixed pulley half body, which is fixed to the input shaft so as not to be movable in an axial direction, and a driving side movable pulley half body, which is mounted on the driving side fixed pulley half body so as to be movable in the axial direction and is moved to the side of the driving side fixed pulley half body in accordance with the rotation of the input shaft, the driven pulley comprises a driven side fixed pulley half body, which is fixed to the output shaft so as not to be movable in the axial direction, and a driven side movable pulley half body, which is mounted on the driven side fixed pulley half body so as to be movable in the axial direction and is biased to the side of the driven side fixed pulley half body, and that there are provided a driven side stopper, which regulates movement of the driven side movable pulley half body in a direction in which a space between the driven side movable pulley half body and the driven side fixed pulley half body increases, and a drive side stopper which regulates movement of the drive side movable pulley half body in a direction in which a space between the drive side movable pulley half body and the drive side fixed pulley half body decreases, and the V belt type continuously variable transmission is constituted such that, in accordance with an increase in an operating time in a state in which the driven side stopper and a driving side stopper are operated using an identical V belt, the V belt type continuously variable transmission is capable of shifting from a state in which the driven side movable pulley half body is in abutment against the driven side stopper and a space is formed between the driving side movable pulley half body and the driving side stopper to a state in which the driving side pulley half body is in abutment against the driving side stopper and a space is formed between the driven side movable pulley half body and the driven side stopper. An invention of claim 4 is a V belt type continuously variable transmission constituted by coupling a drive pulley of a winding diameter variable type, which is mounted on an input shaft, and a driven pulley of a winding diameter variable type, which is mounted on an output shaft parallel with the input shaft, with a V belt, characterized in that the drive pulley comprises a driving side fixed pulley half body, which is fixed to the input shaft so as not to be movable in an axial direction, and a driving side movable pulley half body, which is mounted on the driving side fixed pulley half body so as to be movable in the axial direction and is moved to the side of the driving side fixed pulley half body in accordance with the rotation of the input shaft, the driven pulley comprises a driven side fixed pulley half body, which is fixed to the output shaft so as not to be movable in the axial direction, and a driven side movable pulley half body, which is mounted on the driven side fixed pulley half body so as to be movable in the axial direction and is biased to the side of the driven side fixed pulley half body, and that there are provided a driven side stopper, which regulates movement of the driven side movable 6 pulley half body in a direction in which a space between the driven side movable pulley half body and the driven side fixed pulley half body increases, and a drive side stopper which regulates movement of the drive side movable pulley half body in a direction in which a space between the drive side movable pulley half body and the drive side fixed pulley half body decreases, and the V belt type continuously variable transmission is constituted such that, in accordance with an increase in an operating time in a state in which the driven side stopper and a driving. side stopper are operated using an identical V belt, the V belt type continuously variable transmission is capable of shifting from a state in which the driven side movable pulley half body is in abutment against the driven side stopper and a space is formed between the driving side movable pulley half body and the driving side stopper to a state in which the driving side pulley half body is in abutment against the driving side stopper and a space is formed between the driven side movable pulley half body and the driven side stopper. An invention of claim 5 is a V belt type continuously variable transmission according to claim 3 or 4, characterized in that the driven side stopper is constituted by bringing a boss portion of the driven side movable pulley half body into abutment against a spring bearing member fixed to the output shaft. An invention of claim 6 is a V belt type continuously variable transmission according to claim 3 or 4, characterized in that the driving side stopper is constituted by bringing the weight into abutment against a stopper portion formed in an outer edge portion of the driving side movable pulley half body to regulate a position in radial direction of the weight. An invention of claim 7 is a V belt type continuously variable transmission according to claim 3 or 4, characterized in that the driving side stopper is constituted by bringing a boss portion of the driving side movable pulley half body into abutment against a boss portion of the driving side fixed pulley half body. An invention of claim 8 is a V belt type continuously variable transmission according to claim 3 or 4, characterized in that the driven side movable pulley half body is adapted to be movable in the axial direction and rotate together with the output shaft by engaging a guide pin implanted in the output shaft with a slide groove of the driven side movable pulley half body, and the driven side stopper brings the end of the slide groove of the driven side movab.le pulley half body into abutment with the guide pin. Brief Description of the/Drawings Fig. 1 is a left side view of a motor cycle mounted with a V belt type continuously variable transmission according to an embodiment of the present invention. Fig. 2 is a sectional plan view of an engine unit provided with the V belt type continuously variable transmission. Fig. 3 is a sectional plan view of the V belt type continuously variable transmission. Fig. 4 is a sectional view showing a change in a winding diameter due to abrasionof aVbelt of theVbelt type continuously variable transmission. Fig. 5 is a sectional view showing a change in the winding diameter due to abrasion of the V belt. Fig. 6 is a sectional view showing a change in the winding diameter due to abrasion of the V belt. Fig. 7 is a characteristic chart showing a relationbetween a travel distance and an amount of abrasion of a V belt. Fig. 8 is a characteristic chart showing a relationbetween a travel distance and a reduction gear ratio at top time. Fig. 9 is a characteristic chart showing a relation between a travel distance and an engine speed at top time. Fig. 10 is a sectional view for explaining a driving side stopper according to an embodiment of an invention of claim 5. Fig. 11 is a sectional view showing a change in a winding diameter according to the driving side stopper. Fig. 12 is a sectional view showing a change in the winding diameter according to the driving side stopper. Fig. 13 is a view showing a conventional general V belt type continuously variable transmission. Fig. 14 is a sectional view showing a modification of a stopper of a driven side pulley in the embodiment. Best Mode for Carrying Out the Invention Embodiments of the present invention will be hereinafter described based upon the accompanying drawings. Figs. 1 to 6 are views for explaining a V belt type continuously variable transmission according to an embodiment of the present invention. Fig. 1 is a left side view of a motorcycle mounted with the V belt type continuously variable transmission of this embodiment, Fig. 2 is a sectional plan view of an engine unit provided with the V belt type continuously variable transmission, Fig. 3 is a sectional plan view of the V belt type continuously variable transmission, Figs. 4, 5, and 6 are sectional views showing a change in a winding diameter due to abrasion of a V belt, respectively. Note that the front and rear and the left and right in this embodiment means the front and rear and the left and right viewed from a person sitting on a sheet. In Fig. 1, reference numeral 1 denotes a motorcycle, which has a schematic structure in which front forks 5 having a front wheel 4 axially supported thereon by head pipes 3, which is locked to a front end of a body frame la, are supported so as to be pivotable to the left and right, rear arms 8 having a rear wheel 7 axially supported thereon is supported from a rear armbracket 6, which is locked in a central part of themotorcycle, so as to be swingable vertically, and a sheet 9 including a driver sheet portion 9a and a rear passenger sheet portion 9b is arranged in an upper part of the body frame la. The body frame la includes left and right down tubes lb extending obliquely downward from the head pipes 3, left and right upper tubes lc following rear ends of the respective down tubes lb and extending obliquely upward, and left and right sheet rails 1d traversed in a longitudinal direction between the down tubes lb and the upper tubes lc and joined thereto. In addition, the body frame la is covered by a body cover 10 made of resin including a front cover 10a, a leg shield 10b, a side cover 10c, and the like. A steering handlebar 11 is fixed to an upper end of the front fork 5 and is covered by a handle cover 11a. In addition, a rear cushion 12 is suspended between the rear arms 8 and the rear arm bracket 6. An engine unit 2 is suspended and supported by the down tubes lb of the body frame la. This engine unit 2 is provided with an air-cooling four-cycle single cylinder engine 15, which is mounted with a cylinder axial line A slanted approximately 45 degrees to the front, a V belt type continuously variable transmission 16, a multiple wet centrifugal clutch mechanism 17, and a reduction gear mechanism 18. The engine 15 has a schematic structure in which a cylinder head 20 is connected to an upper interface of a cylinder block 19 and a crankcase 22 housing a crankshaft 28 is connected to a lower interface of the cylinder block 19. Asuctionport (not shown) communicating with a combustion recessed portion 20a is opened on a rear surface of the cylinder head 20, and a carburetor 23 is connected to the suction port via a suction pipe 23a . In addition, an exhaust port (not shown) communicating with the combustion recessedport ion 2 0a is opened on a front surface of the cylinder head 20, and an exhaust pipe 24 is connected to the exhaust port. This exhaust pipe 24 extends downward to the rear of the engine 15 and, then, extends obliquely backward through a right side thereof, and is connected to a muffler 25 disposed on a right side of the rear wheel 7. A spark plug 30 is inserted in the combustion recessed portion 20a. A chain chamber 19a communicating with the inside of the crankcase 22 and the inside of the cylinder head 20 is formed in a left portion of the cylinder block 19, a timing chain 34, which drives to rotate a cam shaft 31 with the crankshaft 28, is disposed in the chain chamber 19a, and a not-shown suction valve and a not-shown exhaust valve is driven to open and close by this cam shaft 31. Apiston 26 is slidably inserted and arranged in a cylinder bore of the cylinder block 19. A small end 27b of a connection rod 27 is coupled to the piston 26, and a large end 27a of the connection rod 27 is coupled to a crankpin 29 which is fit between left and right crank arms 28a and 28b of the crankshaft 28. A transmission shaft 47 is arranged behind the crankshaft 28 in parallel with the crankshaft 28, and a drive shaft 48 is arranged on the left in an axial direction of the transmission shaft 47 so as to be coaxial. A drive sprocket 49 is mounted at a left end of this drive shaft 48, and the drive sprocket 49 is coupled to a driven sprocket 51 of the rear wheel 7 via a chain 50. A generator 42 is mounted at a left end of the crankshaft 28. This generator has a structure in which a rotor 42a is locked to a sleeve 43, which is fitted to the crankshaft 28 in a tapered manner, and a stator 42b opposed to the rotor 42a is fixed to a generator case 44. The crankcase 22 is divided into a first case 40 on the left and a second case 41 on the right in a crankshaft direction. The generator case 44 housing the generator 42 is detachably mounted on the outer side in the crankshaft direction of this first case 40, and a transmission case 45 housing the V belt type continuously variable transmission 16 is mounted on the outer side in the crankshaft direction of the second case 41. The centrifugal clutch mechanism 17 is multiple wet type and has a schematic structure in which a bowl-like outer clutch 83 is spline-fitted so as to rotate with the transmission shaft 47, an inner clutch 84 is arranged coaxially on the inner side in an axial direction of the outer clutch 83, and the inner clutch 84 is spline-fitted to a primary reduction small gear 74, which is rotatably mounted on the transmission shaft 47, so as to rotate with the same. Plural outer clutch plates 85 are arranged in the outer clutch 83, two pressing plates 86, 86 are arranged so as to be located at both ends thereof, and both the clutch plates 85 and the pressing plates 8 6 are engaged in the outer clutch 83 so as to rotate with the outer clutch 83. In addition, inner clutch plates 87 are arranged between the outer clutch plates 85 and the pressing plates 86, and the respective inner clutch plates 87 are engaged with an external periphery of the inner clutch 84 so as to rotate with the inner clutch 84. A cam surface 83a is formed on the inner side of the outer clutch 83, and a weight 88 is disposed between the cam surface 83a and the pressing plate 86 on the outer side. This weight 88 is moved in a clutch connection direction by the cam surface 83a as it moves to the outer side in a radial direction by a centrifugal force of the outer clutch 83, and presses to move the pressing plates 86 to bring the outer clutch plates 85 and the inner clutch plates 87 into a connected state with each other. Note that, in Figs. 2 and 3, a part above an axial line of the centrifugal clutch mechanism 17 shows an interrupted state and a part below the axial line shows a connected state. The reduction gear mechanism 18 has a structure in which a reduction shaft 52 is disposed in parallel with the transmission shaft 47, the primary reduction small gear 74 is mounted on the transmission shaft 47 so as to be rotatable relatively, a primary reduction large gear 75, which engages with the primary reduction small gear 74, is coupled to the reduction shaft 52, a secondary reduction small gear 52a is integrally formed with the reduction gear 52, and a secondary reduction large gear 48a, which engages with the secondary reduction small gear 52a, is integrally formed with the drive shaft 48. The drive shaft 4 8 is disposed on an identical axial line with the transmission shaft 47. A support hole 48b, in which a left end of the transmission shaft 47 is inserted, is recessed at a right end of this drive shaft 48, and the right end of the drive shaft 48 is axially supported by the transmission shaft 47 via a bearing 76 mounted in the support hole 48b. The transmission case 45 is a case of a substantially closed structure, which is formed independently from the crankcase 22, and has an elliptical shape covering most parts of the upper side of the crankcase 22 viewed from a right side thereof. The transmission case 45 includes a case main body 45a of a bottomed box shape opening to the outer side in the crankshaft direction and a cover 45b closing the opening of the case main body 45a airtightly, and is tightened with and fixed to the second case 41 by a bolt 70. A gap "a" is provided between a bottom wall 45c of the case main body 45a and the second case 41, and heat from the engine 15 is restrained from transmitting to the transmission case 45 by this gap "a". An opening 41e having a size allowing the centrifugal clutch mechanism 17 to be taken in and out is formed on the axial direction of the second case 41. This opening 41e is closed by a clutch cover 71 airtightly, and the clutch cover 71 is detachably tightened and fixed to an opening edge of the second case 41 by a bolt 72. Consequently, the centrifugal clutchmechanisml7 can be removed together with the transmission shaft 4 7 by removing the transmission case 4 5 together with a driven pulley 56 of the V belt type continuously variable transmission 16 and removing the clutch cover 71. The V belt type continuously variable transmission 16 has a structure in which a drive pulley 55 is mounted on a right outer end of the crank shaft (input shaft) 28, a driven pulley 56 is mounted on a right outer end of the transmission shaft (output shaft) 47, and a V belt 57 is wound around and coupled to both the pulleys 55, 56. The Vbelt 57 is a belt made of resin having heat resistance and durability and is formed by arranging a large number of resin blocks 57a of a lateral H shape and coupling these resin blocks with a pair of annular coupling members 57b made of heat-resistant rubber. Note that it is also possible to adopt a belt made of rubber as the V belt. The drive pulley 55 has a driving side fixed pulley half body 55a fixed to the right end of the crankshaft 28, and a driving side movable pulley half body 55b which is disposed so as to be slidable in an axial direction to the inner side in the crankshaft direction of the fixed pulley half body 55a and rotate together with the crankshaft 28 via a slide collar 59. A cam plate 58 is disposed on the inner side in the crankshaft direction of the driving side movable pulley half body 55b. This cam plate 58 and the slide collar 59 are mounted on the right end of the crankshaft 28 by spline fitting, and the driving side fixed pulley half body 55a is mounted on the outer side in the axial direction thereof and fastened and fixed by a lock nut 60. A cylindrical boss portion 55d, which is integrally formed with an axial part of the driving side movable pulley half body 55b, is mounted on the slide collar 59 so as to be movable in the axial direction. A cylindrical weight 61 is disposed between the driving side movable pulley half body 55b and the cam plate 58. The driven pulley 56 has a driven side fixed pulley half body 56a fixed to the right outer end of the transmission shaft 47 and a driven side movable pulley haIf body 56b which is disposed on the outer side in the crankshaft direction of the fixed pulley half body 56a so as to be slidable in the axial direction. A cylindrical slide collar 62 is locked to an axial part of the driven side fixed pulley half body 56a, and the slide collar 62 is mounted on the transmission shaft 47 by spline fitting. A cylindrical boss portion 63 locked to an axial part of the driven side movable pulley half body 56b is mounted on this slide collar 62 so as to be movable in the axial direction. Plural slide grooves 63a extending in the axial direction is formed in the boss portion 63, and a guide pin 64, which is implanted and fixed to the slide collar 62, is engaged with the slide grooves 63a, whereby the driven side movable pulley half body 56b rotates together with the fixed pulley half body 56a. A spring bearing member 65 consisting of an annular plate is fixed to an outer end of the slide collar 62 by a circlip 65a, and a coil spring 67, which always biases the driven side movable pulley half body 56b to the side of the fixed pulley half body 56a, is provided between this spring bearing member 65 and the driven side movable pulley half body 56b. As the rotation of the crankshaft 28 increases, the weight 61 is moved to the outer side in the radial direction by a centrifugal force to move the driving side movable pulley half body 55b to the outer side in the axial direction, whereby a winding diameter of the pulley increases. At the same time, the driven side movable pulley half body 56b compresses the coil spring 67 to move to the outer side in the axial direction, whereby the winding diameter of the pulley decreases and a reduction gear ratio decreases . In addition, when the rotation of the crankshaft 28 decreases, the weight 61 moves to the inner side in the radial direction to allow the movement of the driving side movable pulley half body 55b to the inner side in the axial direction, the driven side movable pulley half body 56b is biased by the coil spring 67 to move to the inner side in the axial direction, a winding diameter of the driven pulley 56 increases, whereby the winding diameter of the drive pulley 55 decreases and, as a result, a reduction gear ratio increases. The driven pulley 56 is fastened and fixed to the transmission shaft 4 7 by a lock nut 66 screwed into a tip 47a of the transmission shaft 47. This lock nut 66 is inserted and arranged so as to sink into an outer end 62a of the slide collar 62. Here, an inner diameter of the slide collar 62 is set to be larger stepwise than an outer diameter of the transmission shaft 47, and the tip 47a of the transmission shaft 47 is set to be smaller stepwise. Consequently, the lock nut 66 and a washer can be inserted and arranged in the outer ends 62a of the slide collar 62 without any trouble and, in this way, it becomes possible to locate the lock nut 66 on the inner side in the crankshaft direction than the spring bearing member 65 of the coil spring 67. Since the transmission is constituted as described above, protrusion to the outer side in the transmission shaft direction can be reduced with a simple structure while a necessary length of the coil spring 67 is secured. Then, in the driven pulley 56, there is provided a driven side stopper which regulates a position in the axial direction of the driven side movable pulley half body 56b to a top time position when a space between the driven side movable pulley half body 56b and the driven side fixed pulley 56a is maximized. This driven side stopper is constituted so as to regulate the space of the driven pulley 56 to the space at top time by bringing an outer end surface 63b of the boss portion 63 of the driven side movable pulley half body 56b into abutment against the spring bearing member 65. Note that, as shown in Fig. 14, the driven side stopper may be constituted so as to regulate the space of the driven side pulley 56 to the space at the top time by bringing an end in axial direction 63a' of a slide groove 63a, which is formed in the boss portion 63 of the driven side movable pulley half body 56b, into abutment against the guide pin 64. In addition, in the drive pulley 55, there is provided a driving side stopper which regulates a position in the axial direction of the driving side variable pulley half body 55b to a corrected top time position (position shown in Fig. 5) where a space between the driving side movable pulley half body 55b and the driving side fixed pulley half body 55a is smaller than the space in a top time position (position shown in Fig. 4) where the space is minimized. This driving side stopper is constituted by integrally forming a stopper portion 55c, against which the weight 61 abuts, at an external periphery of the driving side movable pulley half body 55b on the inner side of the crankshaft direction, and regulates a position in the radial direction of the weight 61 with the stopper portion 55c and the cam plate 58 to thereby regulate a space of the drive pulley 55 to a space at corrected top time. The stopper portion 55c is set such that a gap bis formed between the stopper portion 55c and the weight 61 in a state in which the V belt 57 is substantially new and the driven side movable pulley 56b is regulated to the top time position. Next, actions and advantages of this embodiment will be described. Figs. 7 to 9 are characteristic chart for explaining operations as well as actions and advantages of this embodiment, respectively. Fig. 7 shows a relation between a travel distance and a change in an upper width dimension due to abrasion of a V belt. The upper width dimension of the V belt decreases as the travel distance increases. Note that an amount of abrasion of this V belt is substantially the same as that of the conventional one. Fig. 8 shows a relation between a travel distance and a reduction gear ratio at top time. In this embodiment, as the travel distance increases, first, the reduction gear ratio changes to be smaller and, when the travel distance has generally reached a certain travel distance Dl km, the reduction gear ratio is reversed to change to be larger. Moreover, when the travel distance has reached a travel distance D2 km, the reduction gear ratio returns to the original reduction gear ratio and, then, the reduction gear ratio changes to be larger. On the other hand, in the conventional transmission for regulating a top time position on the drive pulley side, the reduction gear ratio changes to be larger as the travel distance increases from an initial stage. Fig. 9 shows a relation between a travel distance and an engine speed at top time. As described above, in the conventional transmission, since the reduction gear ratio deviates to be larger from an initial stage, it is necessary to increase the engine speed in order to obtain a predetermined vehicle speed. On the other hand, in this embodiment, since the reduction gear ratio changes to be smaller up to the vicinity of the certain travel distance Dl km, the predetermined vehicle speed is obtained even at a low engine speed. In addition, the predetermined vehicle speed is obtained without increasing the engine speed until the travel distance exceeds the travel distance D2 km. At an idling time, the drive pulley 55 is in a position at low time where the space between the pulley half bodies is maximized and the winding diameter is minimized, and the driven pulley 56 is in a position at low time where the space between the pulley half bodies is minimized and the winding diameter is maximized by a biasing force of the coil spring 67, whereby the reduction gear ratio is maximized. When the rotation of the crankshaft 28 increases, the weight 61 moves the driving side movable pulley half body 55b to the side of the fixed pulley half body 55a with a centrifugal force, whereby the winding diameter of the drive pulley 55 gradually increases and the driven side movable pulley half body 56b compresses the coil spring 67 to move to the side of the fixed pulley half body 56a, the winding diameter of the driven pulley 56 gradually decreases and the reduction gear ratio gradually decreases. When the rotation of the crankshaft 28 further increases, the driving side movable pulley half body 55b is moved by the centrifugal force of the weight 61 and the winding diameter of the drive pulley 55 further increases and, in accordance with this, the driven side movable pulley half body 56b moves to the outer side in the axial direction, and the outer end surface 63b of the boss portion 63 of the driven side movable pulley half body 56b abuts against the spring bearing member 65. Consequently, the driven pulley 56 is regulated to the top time position where the winding diameter is minimized. In this case, as shown in Fig. 4, when the travel distance is zero or at the initial stage, the gap b exists between the weight 61 and the stopper portion 55c of the driving side movable pulley half body 55b. As the travel distance increases, the V belt 57 is worn as shown in Fig. 7, and the upper width dimension of the belt decreases. For example, when the travel distance reaches Dl km, the upper width dimension of the V belt 57 decreases from L1 at the time when the V belt is new to L1' . Then, the driving side movable pulley half body 55b moves to the side of the fixed pulley half body 55a by an amount of abrasion and the winding diameter of the drive pulley 55 slightly increases from Rl at the initial stage to Rl' , the weight 61 abuts against the stopper portion 55c, and the winding diameter increases to the winding diameter at corrected top time larger than that at top time to be regulated to this winding diameter. On the other hand, since the driven side movable pulley half body 56b of the driven pulley 56 is regulated to the top time position, the V belt 57 moves to the axis side and the winding diameter slightly decreases from R2 at the initial stage to R2' . In this way, as shown in Fig. 8, the reduction gear ratio changes to be smaller by an amount of abrasion of the V belt 57. When the travel distance has reached D2 km and the upper width dimension of the V belt 57 further decreases from LI at the time when the V belt is new to L1' since the driving side movable pulley half body 55b is regulated to the top time, the Vbelt 57 moves to the axis side and the winding diameter returns to Rl' ' which is substantially equal to Rl at the initial stage. On the other hand, the driven side movable pulley half body 56b on the drive pulley 56 side moves to the side of the fixed pulley half body 56a by a biasing force of the coil spring 67 by an amount of abrasion of the V belt 57, whereby the winding diameter of the driven pulley 56 returns to R2' which is substantially equal to R2 at the initial stage. That is, the reduction gear ratio changes to be smaller from the state in which the V belt 57 is new up to the vicinity of the travel distance Dl km and, when the travel distance has exceeded Dl km, the reduction gear ratio starts to change to be larger in the vicinity of D2 km. When the travel distance further increases from this state, the reduction gear ratio gradually changes to be larger. In this way, in this embodiment, since the driven side movable pulley half body 56b of the driven pulley 56 is regulated to the top time position where the winding diameter is minimized, in the period until the travel distance reaches, for example, Dl km as described above, the winding diameter of the drive pulley 55 changes to be larger in accordance with the increase in the travel distance and the winding diameter of the driven pulley 56 changes to be smaller, whereby the reduction gear ratio changes to be smaller. In addition, since the driving side movable pulley half body 55b on the drive pulley 55 side is regulated to the corrected top time position, when the travel distance further increases exceeding Dl km, although the reduction gear ratio has been changing to be smaller to that point, the reduction gear ratio is reversed and changes to return to the original reduction gear ratio. As a result, the vehicle speed at top time does not decrease to the lower limit value even if the amount of abrasion of the V belt 57 increases considerably, the V belt 57 is not required to be changed at an amount of abrasion equivalent to that in the past, and the replacement period of the Vbelt can be extended. Incidentally, a standard for replacement of a V belt is set to a time when the travel distance has reached D2 km in the conventional transmission, whereas, in this embodiment, the replacement period is a time when the travel distance has reached D3 km. In this embodiment, the top time position of the driven side movable pulley half body 56b is regulated by bringing the boss portion 63 of the driven side movable pulley half body 56b into abutment against the spring bearing member 65, and the top time position of the driving side movable pulley half body 55b is regulated by bringing the weight 61 into abutment against the stopper portion 55c of the driving side movable pulley half body 55b. Therefore, the driven side movable pulley half body 56b and the driving side movable pulley half body 55b can be regulated to the top time position and the corrected top time position with a simple structure without providing a separate component or a special stopper mechanism, and an increase in cost can be prevented. Figs. 10 to 12 are views for explaining the driving side stopper according to the present invention. In the figure, reference numerals and signs identical with those in Figs. 4 to 6 denote identical or equivalent components. The driving side stopper of this embodiment is an example in which a projecting portion 55e is formed on an outer end surface of the boss portion 55d of the driving side movable pulley half body 55b, and the projecting portion 55e is brought into abutment against a boss portion 55f of the fixed pulley half body 55a, whereby the driving side movable pulley half body 55b is regulated to the corrected top time position. In such a case, the driving side movable pulley half body 55b can also be regulated to the corrected top time position with a simple structure without providing a separate component or a special stopper mechanism, and the same advantages as the above-mentioned embodiment can be obtained. Inaddition, since a structure for bringing the driving side movable pulley half body 55b into abutment against the fixed pulley half body 55a to regulate it to the top time position is adopted, a pressing force can be prevented from acting on the V beIt 57 by a centrifugal force of the weight 61, and abrasion of the V belt 57 can be restrained. Note that, although the case in which the present invention is described with the case in which it is applied to a V belt type continuously variable transmission of a motorcycle as an example in the above-mentioned embodiment, a scope of application of the present invention is not limited to this, and the present invention can be applied to a V belt type continuously variable transmission for a vehicle such as a motor tricycle or a four wheel car. In addition, although the present invention is described with a V belt of resin as an example in the above-mentioned embodiment, the present invention can be naturally applied to a V belt of rubber, and substantially the same advantages as the above-mentioned embodiment can be obtained in this case. Industrial Applicability In the V belt type continuously variable transmission in accordance with the invention of claim 1 and in accordance with claim 2, since a reduction gear ratio at time when the drive pulley has a maximum winding diameter and the driven pulley has a minimum winding diameter and the number of rotations of an input shaft necessary for obtaining the same number of rotations of an output shaft decrease once and, then, increase in accordance with an increase in an operating time, respectively, an operating time until a rotating speed of the output shaft decreases to a lower limit value becomes long compared with the conventional transmission and, therefore, a replacement period of a V belt can be extended. In the invention of claims 3 and 4, the driven side movable pulley half body on the driven pulley side is regulated to the position where the winding diameter is minimi zed, and the driving side movable pulley half body on the drive pulley side is regulatedto the position where the winding diameter is maximized Thus, when the V belt is worn in accordance with an increase in an operating time from start of operation, the space of the driven pulley does not change and the driving side movable pulley moves from the regulated position to narrow the space of the drive pulley, and the winding diameter is increased. Therefore, the reduction gear ratio changes to be smaller.. In addition, after the driving side movable pulley has reached the regulated position in accordance with an increase in an amount of abrasion of the V belt, the reduction gear ratio changes to increase in accordance with a further increase in the amount of abrasion. In this way, in accordance with an increase in the operating time, the reduction gear ratio changes to be smaller once, changes to return to the initial reduction gear ratio, and, then, changes to increase, whereby the number of rotations of the output shaft does not decrease to a lower limit value until the amount of abrasion of the Vbelt becomes considerably large. As a result, a replacement period of the V belt can be extended. In the invention of claim. 5, the driven side stopper is constituted by bringing the boss portion of the driven side movable pulley half body against the spring bearing member. In the invention of claim 8, the driven side stopper is constituted by bringing the end in axial direction of the slide groove of the driven side movable pulley half body. Therefore, the driven side movable pulley half body can be regulated to the top time position with a simple structure without providing a separate component or a special stopper mechanism, and an increase in cost can be prevented. In the invention of claim 6, the driving side stopper is constituted by bringing the weight into abutment against the stopper portion formed in the outer edge of the driving side movable pulley half body to regulate the position in radial directionof the weight. In the invention of claim 7, thedriving side stopper is constituted by bringing the boss portion of the driving side movable pulley half body into abutment against the boss portion of the driving side fixed pulley half body. Therefore, as in claim 3, the driving side movable pulley half body can be regulated to the top time position with a simple structure without providing a separate component or a special stopper mechanism. We Claim: 1. A V-belt continuously variable transmission, in which a drive pulley (103) of a variable wound diameter type mounted on an input shaft (100) and a driven pulley (107) of a variable wound diameter type mounted on an output shaft (104) in parallel to the input shaft are connected to each other by a V-belt (108), the transmission being characterized in that when the drive pulley has a maximum wound diameter and the driven pulley has a minimum wound diameter, a reduction ratio is increased after being once decreased as an operating time in a state of an operation with the use of the same V-belt is increased. 2. A V-belt continuously variable transmission, in which a drive pulley of a variable wound diameter type mounted on an input shaft and a driven pulley of a variable wound diameter type mounted on an ouput shaft in parallel to the input shaft are connected to each other by a V-belt, the transmission being characterized in that when the drive pulley has a maximum wound diameter and the driven pulley has a minimum wound diameter, the number of revolutions of the input shaft required for obtaining the same number of output revolutions is increased after being once decreased as an operating time in a state of an operation with the use of the same V-belt is increased. 3. The V-belt continuously variable transmission as claimed in claim 1 or 2, wherein the drive pulley comprises a drive-side stationary pulley half fixed axially immovably to the input shaft and a drive-side movable pulley half mounted axially movably relative to the drive-side stationary pulley half and moved toward the drive-side stationary pulley half with rotation of the input shaft, the driven pulley comprises a driven-side stationary pulley half fixed axially immovably to the output shaft and a driven-side movable pulley half mounted axially movably relative to the driven-side stationary pulley half and biased toward the driven-side stationary pulley half by a spring, and the transmission comprising a driven-side stopper that restricts movement of the driven-side movable pulley half in a direction, in which a spacing between the driven-side movable pulley half and the driven-side stationary pulley half is increased , and a drive-side stopper that restricts movement of the drive-side movable pulley half in a direction, in which a spacing between the drive-side movable pulley half and the driven-side stationary pulley half is decreased, and wherein the driven-side stopper and the drive-side stopper are constructed so that as an operating time in a state of an operation with the use of the same V-belt is increased, a state, in which movement of the driven-side movable pulley half is restricted by the driven-side stopper, can shift to a state, in which movement of the drive-side pulley half is restricted by the drive-side stopper. 4. A V-belt continuously variable transmission, in which a drive pulley of a variable wound diameter type mounted on an input shaft and a driven pulley of a variable wound diameter type mounted on an output shaft in parallel to the input shaft are connected to each other by a V-belt, the transmission being characterized in that the drive pulley comprises a drive-side stationary pulley half fixed axially immovably to the input shaft and a drive-side movable pulley half mounted axially movably relative to the drive-side stationary pulley half and moved toward the drive-side stationary pulley half with rotation of the input shaft, the driven pulley comprises a driven-side stationary pulley half fixed axially immovably to the output shaft and a driven-side movable pulley half mounted axially movably relative to the driven-side stationary pulley half and biased toward the driven-side stationary pulley half by a spring, and the transmission comprising a driven-side stopper that restricts movement of the driven-side movable pulley half in a direction, in which a spacing between the driven-side movable pulley half and the driven-side stationary pulley half is increased, and a drive-side stopper that restricts movement of the drive-side movable pulley half in a direction, in which a spacing between the drive-side movable pulley half and the driven-side stationary pulley half is decreased, and wherein the driven-side stopper and the drive-side stopper are constructed so that as an operating time in a state of an operation with the use of the same V-belt is increased, a state, in which movement of the driven-side movable pulley half is restricted by the driven-side stopper can shift to a state, in which movement of the drive-side pulley half is restricted by the drive-side stopper. 5. The V-belt continuously variable transmission as claimed in claim 3 or 4, wherein the driven-side stopper is provided between the driven-side movable pulley half and the output shaft. 6. The V-belt continuously variable transmission as claimed in claim 5, wherein the driven-side stopper is provided between a boss of the driven-side movable pulley half and the output shaft. 7. The V-belt continuously variable transmission as claimed in claim 6, wherein the driven-side stopper is provided between the boss of the driven-side movable pulley half and a slide collar of the driven-side stationary pulley mounted to the output shaft. 8. The V-belt continuously variable transmission as claimed in claim 7, wherein the driven-side stopper is provided between the boss of the driven-side movable pulley half and an outer end of the slide collar. 9. The V-belt continuously variable transmission as claimed in claim 8, wherein the driven-side stopper comprises an outer end surface of the boss of the driven- side movable pulley half and a spring bearing member for the spring, fixed to the outer end of the slide collar. 10. The V-belt continuously variable transmission as claimed in claim 5, wherein the driven-side stopper comprises an outer end surface of a boss of the driven- side movable pulley half and a spring bearing member for the spring, fixed to the output shaft. 11. The V-belt continuously variable transmission as claimed in claim 5, wherein the driven-side movable pulley half is made axially movable and rotatable with the output shaft by engaging a guide pin, which is implanted in the output shaft, with a slide groove on the driven-side movable pulley half, and the driven-side stopper comprises the slide groove on the driven-side movable pulley half and the guide pin. 12. The V-belt continuously variable transmission as claimed in claim 3 or 4, wherein the drive-side stopper is provided between the drive-side movable pulley half and the input shaft. 13. The V-belt continuously variable transmission as claimed in claim 12, comprising a weight provided between the drive-side movable pulley and a cam plate mounted to the input shaft to move radially outward to move the drive-side movable pulley, and wherein the drive-side stopper is formed by restricting a radial position of the weight. 14. The V-belt continuously variable transmission as claimed in claim 13, wherein the drive-side stopper comprises a stopper portion formed on an outer edge of the drive-side movable pulley half and the weight. Dated This 22nd day of February 2005 This invention relates to a V belt continuously variable transmission constituted by coupling a drive pulley 55, which is mounted on a crankshaft (input shaft) 28, and a driven pulley 56, which is mounted on a transmission shaft (output shaft) 47, with a V belt 57, when a driven side variable pulley half body 56b of the driven pulley 56 moves to a top time position where a winding diameter is minimized, a boss portion 63 of the driven side movable pulley half body 56b is brought into abutment against a spring bearing member 65, whereby the driven side movable pulley half body 56b is regulated to the top time position.

Full Text

V BELT TYPE CONTINUOUSLY VARIABLE TRANSMISSION
Technical Field
The present invention relates to aVbelt type continuously
variable transmission which is constituted by coupling a drive
pulley mounted on an input shaft, to which a torque is transmitted,
and a driven pulley, which is mounted on an output shaft, with
a V belt.
Background Art
For example, in a scooter type motorcycle, a V belt type
continuously variable transmission may be adopted as a power
transmission mechanism for transmitting an engine power to a
rear wheel. In this type of V belt type continuously variable
transmission, as shown in Figs. 13(a) and 13(b), a structure
is in general use in which a drive pulley 103, which is mounted
on a crankshaft (input shaft) 100 and has a driving side fixed
pulley half body 101 and a driving side movable pulley half
body 102, and a driven pulley 107, which is mounted on an output
shaft 104 and has a driven side fixed pulley half body 105 and
a driven side movable pulley half body 106, are coupled by a
V belt 108.
In the V belt type continuously variable transmission,

a weight 109 moves the driving side movable pulley half body
102 to the side of the f ixed pulley half body 101 with a centrifugal
force as an engine speed increases, and with this movement,
the driven side movable pulley half body 106 of the driven pulley
107 moves in a direction apart from the fixed pulley half body
105 while compressing a spring 110. Consequently, a winding
diameter of the drive pulley 103 increases and a winding diameter
of the driven pulley 107 decreases, and a reduction gear ratio
decreases to a reduction gear ratio at top time which is a minimum
reduction gear ratio. In this case, it is a general practice
to regulate a position in axial direction of the driving side
movable pulley half body 102 to a top time position by regulating
a position in radial direction of the weight 109 (e.g., see
JP-A-8-178003, JP-A-8-178004).
However, in the case in which a structure for regulating
a reduction gear ratio at top time on a drive pulley side as
in the above-mentioned conventional transmission is adopted,
a winding diameter of the drive pulley is reduced by an amount
of abrasion of a V belt and, in accordance with this, a winding
diameter on a driven pulley side increases. Therefore, there
is a problem in that a reduction gear ratio deviates to the
side of a reduction gear ratio at low time from the reduction
gear ratio at top time, and a maximum speed decreases.
For example, as shown in Figs. 13(a) and 13(b), in the
case in which an upper width dimension is reduced from L1 at

the time when the V belt 108 is new to L1'due to abrasion of
the V belt 108 when the motorcycle has traveled a certain distance
D2 km, the winding diameter of the drive pulley 103 decreases
from Rl in the top time position to Rl' by an amount of this
abrasion and the winding diameter of the driven pulley 107
increases from R2 to R2', and the reduction gear ratio increases
from R2/R1 to R2'/R1' . As a result, since a vehicle speed at
top time with the same engine decreases, the V belt has to be
replaced even if an abrasion loss is within a tolerance. Thus,
improvement is required in realizing extension of a replacement
period.
The present invention has been devised in view of the
above-mentioned circumstances, and it is an object of the present
invention to provide a V belt type continuously variable
transmission which can restrain deviation of a reduction gear
ratio due to abrasion of a V belt to secure a vehicle speed
at the same engine speed and can extend a replacement period
of the V belt.
Disclosure of the Invention
An invention of claim 1 is a V belt type continuously
variable transmission constituted by coupling a drive pulley
of a winding diameter variable type, which is mounted on an
input shaft, and a driven pulley of a winding diameter variable
type, which is mounted on an output shaft parallel with the

input shaft, with a V belt, characterized in that a reduction
gear ratio at time when the drive pulley has a maximum winding
diameter and the driven pulley has a minimum winding diameter
decreases once and, then, increases in accordance with an
increase in an operating time in a state in which the V belt
type continuously variable transmission is operated using an
identical V belt.
An invention of claim 2 is a V belt type continuously
variable transmission constituted by coupling a drive pulley
of a winding diameter variable type, which is mounted on an
input shaft, and a driven pulley of a winding diameter variable
type, which is mounted on an output shaft parallel with the
input shaft, with a V belt, characterized in that the number
of rotations of the input shaft, which is necessary for obtaining
the same number of output rotations, at time when the drive
pulley has a maximum winding diameter and the driven pulley
has a minimum winding diameter decreases once and, then,
increases in accordance with an increase in an operating time
in a state in which the V belt type continuously variable
transmission is operated using an identical V belt.

An invention in claim 3 is a V belt type continuously
variable transmission according to claim 1 or 2, characterized
in that the drive pulley comprises a driving side fixed pulley
half body, which is fixed to the input shaft so as not to be
movable in an axial direction, and a driving side movable pulley

half body, which is mounted on the driving side fixed pulley
half body so as to be movable in the axial direction and is
moved to the side of the driving side fixed pulley half body
in accordance with the rotation of the input shaft, the driven
pulley comprises a driven side fixed pulley half body, which
is fixed to the output shaft so as not to be movable in the
axial direction, and a driven side movable pulley half body,
which is mounted on the driven side fixed pulley half body so
as to be movable in the axial direction and is biased to the
side of the driven side fixed pulley half body, and that there
are provided a driven side stopper, which regulates movement
of the driven side movable pulley half body in a direction in
which a space between the driven side movable pulley half body
and the driven side fixed pulley half body increases, and a
drive side stopper which regulates movement of the drive side
movable pulley half body in a direction in which a space between
the drive side movable pulley half body and the drive side fixed
pulley half body decreases, and the V belt type continuously
variable transmission is constituted such that, in accordance
with an increase in an operating time in a state in which the
driven side stopper and a driving side stopper are operated
using an identical V belt, the V belt type continuously variable
transmission is capable of shifting from a state in which the
driven side movable pulley half body is in abutment against
the driven side stopper and a space is formed between the driving

side movable pulley half body and the driving side stopper to
a state in which the driving side pulley half body is in abutment
against the driving side stopper and a space is formed between
the driven side movable pulley half body and the driven side
stopper.
An invention of claim 4 is a V belt type continuously
variable transmission constituted by coupling a drive pulley
of a winding diameter variable type, which is mounted on an
input shaft, and a driven pulley of a winding diameter variable
type, which is mounted on an output shaft parallel with the
input shaft, with a V belt, characterized in that the drive
pulley comprises a driving side fixed pulley half body, which
is fixed to the input shaft so as not to be movable in an axial
direction, and a driving side movable pulley half body, which
is mounted on the driving side fixed pulley half body so as
to be movable in the axial direction and is moved to the side
of the driving side fixed pulley half body in accordance with
the rotation of the input shaft, the driven pulley comprises
a driven side fixed pulley half body, which is fixed to the
output shaft so as not to be movable in the axial direction,
and a driven side movable pulley half body, which is mounted
on the driven side fixed pulley half body so as to be movable
in the axial direction and is biased to the side of the driven
side fixed pulley half body, and that there are provided a driven
side stopper, which regulates movement of the driven side movable
6

pulley half body in a direction in which a space between the
driven side movable pulley half body and the driven side fixed
pulley half body increases, and a drive side stopper which
regulates movement of the drive side movable pulley half body
in a direction in which a space between the drive side movable
pulley half body and the drive side fixed pulley half body
decreases, and the V belt type continuously variable
transmission is constituted such that, in accordance with an
increase in an operating time in a state in which the driven
side stopper and a driving. side stopper are operated using an
identical V belt, the V belt type continuously variable
transmission is capable of shifting from a state in which the
driven side movable pulley half body is in abutment against
the driven side stopper and a space is formed between the driving
side movable pulley half body and the driving side stopper to
a state in which the driving side pulley half body is in abutment
against the driving side stopper and a space is formed between
the driven side movable pulley half body and the driven side
stopper.
An invention of claim 5 is a V belt type continuously
variable transmission according to claim 3 or 4, characterized
in that the driven side stopper is constituted by bringing a
boss portion of the driven side movable pulley half body into
abutment against a spring bearing member fixed to the output
shaft.

An invention of claim 6 is a V belt type continuously
variable transmission according to claim 3 or 4, characterized
in that the driving side stopper is constituted by bringing
the weight into abutment against a stopper portion formed in
an outer edge portion of the driving side movable pulley half
body to regulate a position in radial direction of the weight.
An invention of claim 7 is a V belt type continuously
variable transmission according to claim 3 or 4, characterized
in that the driving side stopper is constituted by bringing
a boss portion of the driving side movable pulley half body
into abutment against a boss portion of the driving side fixed
pulley half body.
An invention of claim 8 is a V belt type continuously
variable transmission according to claim 3 or 4, characterized
in that the driven side movable pulley half body is adapted
to be movable in the axial direction and rotate together with
the output shaft by engaging a guide pin implanted in the output
shaft with a slide groove of the driven side movable pulley
half body, and the driven side stopper brings the end of the
slide groove of the driven side movab.le pulley half body into
abutment with the guide pin.
Brief Description of the/Drawings
Fig. 1 is a left side view of a motor cycle mounted with
a V belt type continuously variable transmission according to

an embodiment of the present invention.
Fig. 2 is a sectional plan view of an engine unit provided
with the V belt type continuously variable transmission.
Fig. 3 is a sectional plan view of the V belt type
continuously variable transmission.
Fig. 4 is a sectional view showing a change in a winding
diameter due to abrasionof aVbelt of theVbelt type continuously
variable transmission.
Fig. 5 is a sectional view showing a change in the winding
diameter due to abrasion of the V belt.
Fig. 6 is a sectional view showing a change in the winding
diameter due to abrasion of the V belt.
Fig. 7 is a characteristic chart showing a relationbetween
a travel distance and an amount of abrasion of a V belt.
Fig. 8 is a characteristic chart showing a relationbetween
a travel distance and a reduction gear ratio at top time.
Fig. 9 is a characteristic chart showing a relation between
a travel distance and an engine speed at top time.
Fig. 10 is a sectional view for explaining a driving side
stopper according to an embodiment of an invention of claim
5.
Fig. 11 is a sectional view showing a change in a winding
diameter according to the driving side stopper.
Fig. 12 is a sectional view showing a change in the winding
diameter according to the driving side stopper.

Fig. 13 is a view showing a conventional general V belt
type continuously variable transmission.
Fig. 14 is a sectional view showing a modification of
a stopper of a driven side pulley in the embodiment.
Best Mode for Carrying Out the Invention
Embodiments of the present invention will be hereinafter
described based upon the accompanying drawings.
Figs. 1 to 6 are views for explaining a V belt type
continuously variable transmission according to an embodiment
of the present invention. Fig. 1 is a left side view of a
motorcycle mounted with the V belt type continuously variable
transmission of this embodiment, Fig. 2 is a sectional plan
view of an engine unit provided with the V belt type continuously
variable transmission, Fig. 3 is a sectional plan view of the
V belt type continuously variable transmission, Figs. 4, 5,
and 6 are sectional views showing a change in a winding diameter
due to abrasion of a V belt, respectively. Note that the front
and rear and the left and right in this embodiment means the
front and rear and the left and right viewed from a person sitting
on a sheet.
In Fig. 1, reference numeral 1 denotes a motorcycle, which
has a schematic structure in which front forks 5 having a front
wheel 4 axially supported thereon by head pipes 3, which is
locked to a front end of a body frame la, are supported so as

to be pivotable to the left and right, rear arms 8 having a
rear wheel 7 axially supported thereon is supported from a rear
armbracket 6, which is locked in a central part of themotorcycle,
so as to be swingable vertically, and a sheet 9 including a
driver sheet portion 9a and a rear passenger sheet portion 9b
is arranged in an upper part of the body frame la.
The body frame la includes left and right down tubes lb
extending obliquely downward from the head pipes 3, left and
right upper tubes lc following rear ends of the respective down
tubes lb and extending obliquely upward, and left and right
sheet rails 1d traversed in a longitudinal direction between
the down tubes lb and the upper tubes lc and joined thereto.
In addition, the body frame la is covered by a body cover 10
made of resin including a front cover 10a, a leg shield 10b,
a side cover 10c, and the like.
A steering handlebar 11 is fixed to an upper end of the
front fork 5 and is covered by a handle cover 11a. In addition,
a rear cushion 12 is suspended between the rear arms 8 and the
rear arm bracket 6.
An engine unit 2 is suspended and supported by the down
tubes lb of the body frame la. This engine unit 2 is provided
with an air-cooling four-cycle single cylinder engine 15, which
is mounted with a cylinder axial line A slanted approximately
45 degrees to the front, a V belt type continuously variable
transmission 16, a multiple wet centrifugal clutch mechanism

17, and a reduction gear mechanism 18.
The engine 15 has a schematic structure in which a cylinder
head 20 is connected to an upper interface of a cylinder block
19 and a crankcase 22 housing a crankshaft 28 is connected to
a lower interface of the cylinder block 19.
Asuctionport (not shown) communicating with a combustion
recessed portion 20a is opened on a rear surface of the cylinder
head 20, and a carburetor 23 is connected to the suction port
via a suction pipe 23a . In addition, an exhaust port (not shown)
communicating with the combustion recessedport ion 2 0a is opened
on a front surface of the cylinder head 20, and an exhaust pipe
24 is connected to the exhaust port. This exhaust pipe 24 extends
downward to the rear of the engine 15 and, then, extends obliquely
backward through a right side thereof, and is connected to a
muffler 25 disposed on a right side of the rear wheel 7. A
spark plug 30 is inserted in the combustion recessed portion
20a.
A chain chamber 19a communicating with the inside of the
crankcase 22 and the inside of the cylinder head 20 is formed
in a left portion of the cylinder block 19, a timing chain 34,
which drives to rotate a cam shaft 31 with the crankshaft 28,
is disposed in the chain chamber 19a, and a not-shown suction
valve and a not-shown exhaust valve is driven to open and close
by this cam shaft 31.
Apiston 26 is slidably inserted and arranged in a cylinder

bore of the cylinder block 19. A small end 27b of a connection
rod 27 is coupled to the piston 26, and a large end 27a of the
connection rod 27 is coupled to a crankpin 29 which is fit between
left and right crank arms 28a and 28b of the crankshaft 28.
A transmission shaft 47 is arranged behind the crankshaft
28 in parallel with the crankshaft 28, and a drive shaft 48
is arranged on the left in an axial direction of the transmission
shaft 47 so as to be coaxial. A drive sprocket 49 is mounted
at a left end of this drive shaft 48, and the drive sprocket
49 is coupled to a driven sprocket 51 of the rear wheel 7 via
a chain 50.
A generator 42 is mounted at a left end of the crankshaft
28. This generator has a structure in which a rotor 42a is
locked to a sleeve 43, which is fitted to the crankshaft 28
in a tapered manner, and a stator 42b opposed to the rotor 42a
is fixed to a generator case 44.
The crankcase 22 is divided into a first case 40 on the
left and a second case 41 on the right in a crankshaft direction.
The generator case 44 housing the generator 42 is detachably
mounted on the outer side in the crankshaft direction of this
first case 40, and a transmission case 45 housing the V belt
type continuously variable transmission 16 is mounted on the
outer side in the crankshaft direction of the second case 41.
The centrifugal clutch mechanism 17 is multiple wet type
and has a schematic structure in which a bowl-like outer clutch

83 is spline-fitted so as to rotate with the transmission shaft
47, an inner clutch 84 is arranged coaxially on the inner side
in an axial direction of the outer clutch 83, and the inner
clutch 84 is spline-fitted to a primary reduction small gear
74, which is rotatably mounted on the transmission shaft 47,
so as to rotate with the same.
Plural outer clutch plates 85 are arranged in the outer
clutch 83, two pressing plates 86, 86 are arranged so as to
be located at both ends thereof, and both the clutch plates
85 and the pressing plates 8 6 are engaged in the outer clutch
83 so as to rotate with the outer clutch 83. In addition, inner
clutch plates 87 are arranged between the outer clutch plates
85 and the pressing plates 86, and the respective inner clutch
plates 87 are engaged with an external periphery of the inner
clutch 84 so as to rotate with the inner clutch 84.
A cam surface 83a is formed on the inner side of the outer
clutch 83, and a weight 88 is disposed between the cam surface
83a and the pressing plate 86 on the outer side. This weight
88 is moved in a clutch connection direction by the cam surface
83a as it moves to the outer side in a radial direction by a
centrifugal force of the outer clutch 83, and presses to move
the pressing plates 86 to bring the outer clutch plates 85 and
the inner clutch plates 87 into a connected state with each
other. Note that, in Figs. 2 and 3, a part above an axial line
of the centrifugal clutch mechanism 17 shows an interrupted

state and a part below the axial line shows a connected state.
The reduction gear mechanism 18 has a structure in which
a reduction shaft 52 is disposed in parallel with the
transmission shaft 47, the primary reduction small gear 74 is
mounted on the transmission shaft 47 so as to be rotatable
relatively, a primary reduction large gear 75, which engages
with the primary reduction small gear 74, is coupled to the
reduction shaft 52, a secondary reduction small gear 52a is
integrally formed with the reduction gear 52, and a secondary
reduction large gear 48a, which engages with the secondary
reduction small gear 52a, is integrally formed with the drive
shaft 48.
The drive shaft 4 8 is disposed on an identical axial line
with the transmission shaft 47. A support hole 48b, in which
a left end of the transmission shaft 47 is inserted, is recessed
at a right end of this drive shaft 48, and the right end of
the drive shaft 48 is axially supported by the transmission
shaft 47 via a bearing 76 mounted in the support hole 48b.
The transmission case 45 is a case of a substantially
closed structure, which is formed independently from the
crankcase 22, and has an elliptical shape covering most parts
of the upper side of the crankcase 22 viewed from a right side
thereof. The transmission case 45 includes a case main body
45a of a bottomed box shape opening to the outer side in the
crankshaft direction and a cover 45b closing the opening of

the case main body 45a airtightly, and is tightened with and
fixed to the second case 41 by a bolt 70. A gap "a" is provided
between a bottom wall 45c of the case main body 45a and the
second case 41, and heat from the engine 15 is restrained from
transmitting to the transmission case 45 by this gap "a".
An opening 41e having a size allowing the centrifugal
clutch mechanism 17 to be taken in and out is formed on the
axial direction of the second case 41. This opening 41e is
closed by a clutch cover 71 airtightly, and the clutch cover
71 is detachably tightened and fixed to an opening edge of the
second case 41 by a bolt 72. Consequently, the centrifugal
clutchmechanisml7 can be removed together with the transmission
shaft 4 7 by removing the transmission case 4 5 together with
a driven pulley 56 of the V belt type continuously variable
transmission 16 and removing the clutch cover 71.
The V belt type continuously variable transmission 16
has a structure in which a drive pulley 55 is mounted on a right
outer end of the crank shaft (input shaft) 28, a driven pulley
56 is mounted on a right outer end of the transmission shaft
(output shaft) 47, and a V belt 57 is wound around and coupled
to both the pulleys 55, 56.
The Vbelt 57 is a belt made of resin having heat resistance
and durability and is formed by arranging a large number of
resin blocks 57a of a lateral H shape and coupling these resin
blocks with a pair of annular coupling members 57b made of

heat-resistant rubber. Note that it is also possible to adopt
a belt made of rubber as the V belt.
The drive pulley 55 has a driving side fixed pulley half
body 55a fixed to the right end of the crankshaft 28, and a
driving side movable pulley half body 55b which is disposed
so as to be slidable in an axial direction to the inner side
in the crankshaft direction of the fixed pulley half body 55a
and rotate together with the crankshaft 28 via a slide collar
59.
A cam plate 58 is disposed on the inner side in the
crankshaft direction of the driving side movable pulley half
body 55b. This cam plate 58 and the slide collar 59 are mounted
on the right end of the crankshaft 28 by spline fitting, and
the driving side fixed pulley half body 55a is mounted on the
outer side in the axial direction thereof and fastened and fixed
by a lock nut 60. A cylindrical boss portion 55d, which is
integrally formed with an axial part of the driving side movable
pulley half body 55b, is mounted on the slide collar 59 so as
to be movable in the axial direction. A cylindrical weight
61 is disposed between the driving side movable pulley half
body 55b and the cam plate 58.
The driven pulley 56 has a driven side fixed pulley half
body 56a fixed to the right outer end of the transmission shaft
47 and a driven side movable pulley haIf body 56b which is disposed
on the outer side in the crankshaft direction of the fixed pulley

half body 56a so as to be slidable in the axial direction.
A cylindrical slide collar 62 is locked to an axial part
of the driven side fixed pulley half body 56a, and the slide
collar 62 is mounted on the transmission shaft 47 by spline
fitting. A cylindrical boss portion 63 locked to an axial part
of the driven side movable pulley half body 56b is mounted on
this slide collar 62 so as to be movable in the axial direction.
Plural slide grooves 63a extending in the axial direction
is formed in the boss portion 63, and a guide pin 64, which
is implanted and fixed to the slide collar 62, is engaged with
the slide grooves 63a, whereby the driven side movable pulley
half body 56b rotates together with the fixed pulley half body
56a.
A spring bearing member 65 consisting of an annular plate
is fixed to an outer end of the slide collar 62 by a circlip
65a, and a coil spring 67, which always biases the driven side
movable pulley half body 56b to the side of the fixed pulley
half body 56a, is provided between this spring bearing member
65 and the driven side movable pulley half body 56b.
As the rotation of the crankshaft 28 increases, the weight
61 is moved to the outer side in the radial direction by a
centrifugal force to move the driving side movable pulley half
body 55b to the outer side in the axial direction, whereby a
winding diameter of the pulley increases. At the same time,
the driven side movable pulley half body 56b compresses the

coil spring 67 to move to the outer side in the axial direction,
whereby the winding diameter of the pulley decreases and a
reduction gear ratio decreases . In addition, when the rotation
of the crankshaft 28 decreases, the weight 61 moves to the inner
side in the radial direction to allow the movement of the driving
side movable pulley half body 55b to the inner side in the axial
direction, the driven side movable pulley half body 56b is biased
by the coil spring 67 to move to the inner side in the axial
direction, a winding diameter of the driven pulley 56 increases,
whereby the winding diameter of the drive pulley 55 decreases
and, as a result, a reduction gear ratio increases.
The driven pulley 56 is fastened and fixed to the
transmission shaft 4 7 by a lock nut 66 screwed into a tip 47a
of the transmission shaft 47. This lock nut 66 is inserted
and arranged so as to sink into an outer end 62a of the slide
collar 62.
Here, an inner diameter of the slide collar 62 is set
to be larger stepwise than an outer diameter of the transmission
shaft 47, and the tip 47a of the transmission shaft 47 is set
to be smaller stepwise. Consequently, the lock nut 66 and a
washer can be inserted and arranged in the outer ends 62a of
the slide collar 62 without any trouble and, in this way, it
becomes possible to locate the lock nut 66 on the inner side
in the crankshaft direction than the spring bearing member 65
of the coil spring 67. Since the transmission is constituted

as described above, protrusion to the outer side in the
transmission shaft direction can be reduced with a simple
structure while a necessary length of the coil spring 67 is
secured.
Then, in the driven pulley 56, there is provided a driven
side stopper which regulates a position in the axial direction
of the driven side movable pulley half body 56b to a top time
position when a space between the driven side movable pulley
half body 56b and the driven side fixed pulley 56a is maximized.
This driven side stopper is constituted so as to regulate the
space of the driven pulley 56 to the space at top time by bringing
an outer end surface 63b of the boss portion 63 of the driven
side movable pulley half body 56b into abutment against the
spring bearing member 65.
Note that, as shown in Fig. 14, the driven side stopper
may be constituted so as to regulate the space of the driven
side pulley 56 to the space at the top time by bringing an end
in axial direction 63a' of a slide groove 63a, which is formed
in the boss portion 63 of the driven side movable pulley half
body 56b, into abutment against the guide pin 64.
In addition, in the drive pulley 55, there is provided
a driving side stopper which regulates a position in the axial
direction of the driving side variable pulley half body 55b
to a corrected top time position (position shown in Fig. 5)
where a space between the driving side movable pulley half body

55b and the driving side fixed pulley half body 55a is smaller
than the space in a top time position (position shown in Fig.
4) where the space is minimized. This driving side stopper
is constituted by integrally forming a stopper portion 55c,
against which the weight 61 abuts, at an external periphery
of the driving side movable pulley half body 55b on the inner
side of the crankshaft direction, and regulates a position in
the radial direction of the weight 61 with the stopper portion
55c and the cam plate 58 to thereby regulate a space of the
drive pulley 55 to a space at corrected top time. The stopper
portion 55c is set such that a gap bis formed between the stopper
portion 55c and the weight 61 in a state in which the V belt
57 is substantially new and the driven side movable pulley 56b
is regulated to the top time position.
Next, actions and advantages of this embodiment will be
described.
Figs. 7 to 9 are characteristic chart for explaining
operations as well as actions and advantages of this embodiment,
respectively.
Fig. 7 shows a relation between a travel distance and
a change in an upper width dimension due to abrasion of a V
belt. The upper width dimension of the V belt decreases as
the travel distance increases. Note that an amount of abrasion
of this V belt is substantially the same as that of the
conventional one.

Fig. 8 shows a relation between a travel distance and
a reduction gear ratio at top time. In this embodiment, as
the travel distance increases, first, the reduction gear ratio
changes to be smaller and, when the travel distance has generally
reached a certain travel distance Dl km, the reduction gear
ratio is reversed to change to be larger. Moreover, when the
travel distance has reached a travel distance D2 km, the
reduction gear ratio returns to the original reduction gear
ratio and, then, the reduction gear ratio changes to be larger.
On the other hand, in the conventional transmission for
regulating a top time position on the drive pulley side, the
reduction gear ratio changes to be larger as the travel distance
increases from an initial stage.
Fig. 9 shows a relation between a travel distance and
an engine speed at top time. As described above, in the
conventional transmission, since the reduction gear ratio
deviates to be larger from an initial stage, it is necessary
to increase the engine speed in order to obtain a predetermined
vehicle speed. On the other hand, in this embodiment, since
the reduction gear ratio changes to be smaller up to the vicinity
of the certain travel distance Dl km, the predetermined vehicle
speed is obtained even at a low engine speed. In addition,
the predetermined vehicle speed is obtained without increasing
the engine speed until the travel distance exceeds the travel
distance D2 km.

At an idling time, the drive pulley 55 is in a position
at low time where the space between the pulley half bodies is
maximized and the winding diameter is minimized, and the driven
pulley 56 is in a position at low time where the space between
the pulley half bodies is minimized and the winding diameter
is maximized by a biasing force of the coil spring 67, whereby
the reduction gear ratio is maximized.
When the rotation of the crankshaft 28 increases, the
weight 61 moves the driving side movable pulley half body 55b
to the side of the fixed pulley half body 55a with a centrifugal
force, whereby the winding diameter of the drive pulley 55
gradually increases and the driven side movable pulley half
body 56b compresses the coil spring 67 to move to the side of
the fixed pulley half body 56a, the winding diameter of the
driven pulley 56 gradually decreases and the reduction gear
ratio gradually decreases.
When the rotation of the crankshaft 28 further increases,
the driving side movable pulley half body 55b is moved by the
centrifugal force of the weight 61 and the winding diameter
of the drive pulley 55 further increases and, in accordance
with this, the driven side movable pulley half body 56b moves
to the outer side in the axial direction, and the outer end
surface 63b of the boss portion 63 of the driven side movable
pulley half body 56b abuts against the spring bearing member
65. Consequently, the driven pulley 56 is regulated to the

top time position where the winding diameter is minimized. In
this case, as shown in Fig. 4, when the travel distance is zero
or at the initial stage, the gap b exists between the weight
61 and the stopper portion 55c of the driving side movable pulley
half body 55b.
As the travel distance increases, the V belt 57 is worn
as shown in Fig. 7, and the upper width dimension of the belt
decreases. For example, when the travel distance reaches Dl
km, the upper width dimension of the V belt 57 decreases from
L1 at the time when the V belt is new to L1' . Then, the driving
side movable pulley half body 55b moves to the side of the fixed
pulley half body 55a by an amount of abrasion and the winding
diameter of the drive pulley 55 slightly increases from Rl at
the initial stage to Rl' , the weight 61 abuts against the stopper
portion 55c, and the winding diameter increases to the winding
diameter at corrected top time larger than that at top time
to be regulated to this winding diameter.
On the other hand, since the driven side movable pulley
half body 56b of the driven pulley 56 is regulated to the top
time position, the V belt 57 moves to the axis side and the
winding diameter slightly decreases from R2 at the initial stage
to R2' . In this way, as shown in Fig. 8, the reduction gear
ratio changes to be smaller by an amount of abrasion of the
V belt 57.
When the travel distance has reached D2 km and the upper

width dimension of the V belt 57 further decreases from LI at
the time when the V belt is new to L1' since the driving side
movable pulley half body 55b is regulated to the top time, the
Vbelt 57 moves to the axis side and the winding diameter returns
to Rl' ' which is substantially equal to Rl at the initial stage.
On the other hand, the driven side movable pulley half body
56b on the drive pulley 56 side moves to the side of the fixed
pulley half body 56a by a biasing force of the coil spring 67
by an amount of abrasion of the V belt 57, whereby the winding
diameter of the driven pulley 56 returns to R2' which is
substantially equal to R2 at the initial stage.
That is, the reduction gear ratio changes to be smaller
from the state in which the V belt 57 is new up to the vicinity
of the travel distance Dl km and, when the travel distance has
exceeded Dl km, the reduction gear ratio starts to change to
be larger in the vicinity of D2 km. When the travel distance
further increases from this state, the reduction gear ratio
gradually changes to be larger.
In this way, in this embodiment, since the driven side
movable pulley half body 56b of the driven pulley 56 is regulated
to the top time position where the winding diameter is minimized,
in the period until the travel distance reaches, for example,
Dl km as described above, the winding diameter of the drive
pulley 55 changes to be larger in accordance with the increase
in the travel distance and the winding diameter of the driven

pulley 56 changes to be smaller, whereby the reduction gear
ratio changes to be smaller. In addition, since the driving
side movable pulley half body 55b on the drive pulley 55 side
is regulated to the corrected top time position, when the travel
distance further increases exceeding Dl km, although the
reduction gear ratio has been changing to be smaller to that
point, the reduction gear ratio is reversed and changes to return
to the original reduction gear ratio. As a result, the vehicle
speed at top time does not decrease to the lower limit value
even if the amount of abrasion of the V belt 57 increases
considerably, the V belt 57 is not required to be changed at
an amount of abrasion equivalent to that in the past, and the
replacement period of the Vbelt can be extended. Incidentally,
a standard for replacement of a V belt is set to a time when
the travel distance has reached D2 km in the conventional
transmission, whereas, in this embodiment, the replacement
period is a time when the travel distance has reached D3 km.
In this embodiment, the top time position of the driven
side movable pulley half body 56b is regulated by bringing the
boss portion 63 of the driven side movable pulley half body
56b into abutment against the spring bearing member 65, and
the top time position of the driving side movable pulley half
body 55b is regulated by bringing the weight 61 into abutment
against the stopper portion 55c of the driving side movable
pulley half body 55b. Therefore, the driven side movable pulley

half body 56b and the driving side movable pulley half body
55b can be regulated to the top time position and the corrected
top time position with a simple structure without providing
a separate component or a special stopper mechanism, and an
increase in cost can be prevented.
Figs. 10 to 12 are views for explaining the driving side
stopper according to the present invention. In the figure,
reference numerals and signs identical with those in Figs. 4
to 6 denote identical or equivalent components.
The driving side stopper of this embodiment is an example
in which a projecting portion 55e is formed on an outer end
surface of the boss portion 55d of the driving side movable
pulley half body 55b, and the projecting portion 55e is brought
into abutment against a boss portion 55f of the fixed pulley
half body 55a, whereby the driving side movable pulley half
body 55b is regulated to the corrected top time position.
In such a case, the driving side movable pulley half body
55b can also be regulated to the corrected top time position
with a simple structure without providing a separate component
or a special stopper mechanism, and the same advantages as the
above-mentioned embodiment can be obtained. Inaddition, since
a structure for bringing the driving side movable pulley half
body 55b into abutment against the fixed pulley half body 55a
to regulate it to the top time position is adopted, a pressing
force can be prevented from acting on the V beIt 57 by a centrifugal

force of the weight 61, and abrasion of the V belt 57 can be
restrained.
Note that, although the case in which the present invention
is described with the case in which it is applied to a V belt
type continuously variable transmission of a motorcycle as an
example in the above-mentioned embodiment, a scope of
application of the present invention is not limited to this,
and the present invention can be applied to a V belt type
continuously variable transmission for a vehicle such as a motor
tricycle or a four wheel car.
In addition, although the present invention is described
with a V belt of resin as an example in the above-mentioned
embodiment, the present invention can be naturally applied to
a V belt of rubber, and substantially the same advantages as
the above-mentioned embodiment can be obtained in this case.
Industrial Applicability
In the V belt type continuously variable transmission
in accordance with the invention of claim 1 and in accordance
with claim 2, since a reduction gear ratio at time when the
drive pulley has a maximum winding diameter and the driven pulley
has a minimum winding diameter and the number of rotations of
an input shaft necessary for obtaining the same number of
rotations of an output shaft decrease once and, then, increase
in accordance with an increase in an operating time, respectively,

an operating time until a rotating speed of the output shaft
decreases to a lower limit value becomes long compared with
the conventional transmission and, therefore, a replacement
period of a V belt can be extended.
In the invention of claims 3 and 4, the driven side movable
pulley half body on the driven pulley side is regulated to the
position where the winding diameter is minimi zed, and the driving
side movable pulley half body on the drive pulley side is
regulatedto the position where the winding diameter is maximized
Thus, when the V belt is worn in accordance with an increase
in an operating time from start of operation, the space of the
driven pulley does not change and the driving side movable pulley
moves from the regulated position to narrow the space of the
drive pulley, and the winding diameter is increased. Therefore,
the reduction gear ratio changes to be smaller.. In addition,
after the driving side movable pulley has reached the regulated
position in accordance with an increase in an amount of abrasion
of the V belt, the reduction gear ratio changes to increase
in accordance with a further increase in the amount of abrasion.
In this way, in accordance with an increase in the operating
time, the reduction gear ratio changes to be smaller once,
changes to return to the initial reduction gear ratio, and,
then, changes to increase, whereby the number of rotations of
the output shaft does not decrease to a lower limit value until
the amount of abrasion of the Vbelt becomes considerably large.

As a result, a replacement period of the V belt can be extended.
In the invention of claim. 5, the driven side stopper is
constituted by bringing the boss portion of the driven side
movable pulley half body against the spring bearing member.
In the invention of claim 8, the driven side stopper is
constituted by bringing the end in axial direction of the slide
groove of the driven side movable pulley half body. Therefore,
the driven side movable pulley half body can be regulated to
the top time position with a simple structure without providing
a separate component or a special stopper mechanism, and an
increase in cost can be prevented.
In the invention of claim 6, the driving side stopper
is constituted by bringing the weight into abutment against
the stopper portion formed in the outer edge of the driving
side movable pulley half body to regulate the position in radial
directionof the weight. In the invention of claim 7, thedriving
side stopper is constituted by bringing the boss portion of
the driving side movable pulley half body into abutment against
the boss portion of the driving side fixed pulley half body.
Therefore, as in claim 3, the driving side movable pulley half
body can be regulated to the top time position with a simple
structure without providing a separate component or a special
stopper mechanism.

We Claim:
1. A V-belt continuously variable transmission, in which a drive pulley (103) of a
variable wound diameter type mounted on an input shaft (100) and a driven
pulley (107) of a variable wound diameter type mounted on an output shaft
(104) in parallel to the input shaft are connected to each other by a V-belt (108),
the transmission being characterized in that when the drive pulley has a
maximum wound diameter and the driven pulley has a minimum wound
diameter, a reduction ratio is increased after being once decreased as an
operating time in a state of an operation with the use of the same V-belt is
increased.
2. A V-belt continuously variable transmission, in which a drive pulley of a
variable wound diameter type mounted on an input shaft and a driven pulley of a
variable wound diameter type mounted on an ouput shaft in parallel to the input
shaft are connected to each other by a V-belt, the transmission being
characterized in that when the drive pulley has a maximum wound diameter and
the driven pulley has a minimum wound diameter, the number of revolutions of
the input shaft required for obtaining the same number of output revolutions is
increased after being once decreased as an operating time in a state of an
operation with the use of the same V-belt is increased.
3. The V-belt continuously variable transmission as claimed in claim 1 or 2,
wherein the drive pulley comprises a drive-side stationary pulley half fixed axially
immovably to the input shaft and a drive-side movable pulley half mounted
axially movably relative to the drive-side stationary pulley half

and moved toward the drive-side stationary pulley half with rotation of the input
shaft, the driven pulley comprises a driven-side stationary pulley half fixed axially
immovably to the output shaft and a driven-side movable pulley half mounted
axially movably relative to the driven-side stationary pulley half and biased
toward the driven-side stationary pulley half by a spring, and the transmission
comprising a driven-side stopper that restricts movement of the driven-side
movable pulley half in a direction, in which a spacing between the driven-side
movable pulley half and the driven-side stationary pulley half is increased , and a
drive-side stopper that restricts movement of the drive-side movable pulley half
in a direction, in which a spacing between the drive-side movable pulley half and
the driven-side stationary pulley half is decreased, and wherein the driven-side
stopper and the drive-side stopper are constructed so that as an operating time
in a state of an operation with the use of the same V-belt is increased, a state, in
which movement of the driven-side movable pulley half is restricted by the
driven-side stopper, can shift to a state, in which movement of the drive-side
pulley half is restricted by the drive-side stopper.
4. A V-belt continuously variable transmission, in which a drive pulley of a
variable wound diameter type mounted on an input shaft and a driven pulley of a
variable wound diameter type mounted on an output shaft in parallel to the input
shaft are connected to each other by a V-belt, the transmission being
characterized in that the drive pulley comprises a drive-side stationary pulley half
fixed axially immovably to the input shaft and a drive-side movable pulley half
mounted axially movably relative to the drive-side stationary pulley half and
moved toward the drive-side stationary pulley half with rotation of the input
shaft, the driven pulley comprises a driven-side stationary pulley half fixed axially

immovably to the output shaft and a driven-side movable pulley half mounted
axially movably relative to the driven-side stationary pulley half and biased
toward the driven-side stationary pulley half by a spring, and the transmission
comprising a driven-side stopper that restricts movement of the driven-side
movable pulley half in a direction, in which a spacing between the driven-side
movable pulley half and the driven-side stationary pulley half is increased, and a
drive-side stopper that restricts movement of the drive-side movable pulley half
in a direction, in which a spacing between the drive-side movable pulley half and
the driven-side stationary pulley half is decreased, and wherein the driven-side
stopper and the drive-side stopper are constructed so that as an operating time
in a state of an operation with the use of the same V-belt is increased, a state, in
which movement of the driven-side movable pulley half is restricted by the
driven-side stopper can shift to a state, in which movement of the drive-side
pulley half is restricted by the drive-side stopper.
5. The V-belt continuously variable transmission as claimed in claim 3 or 4,
wherein the driven-side stopper is provided between the driven-side movable
pulley half and the output shaft.
6. The V-belt continuously variable transmission as claimed in claim 5, wherein
the driven-side stopper is provided between a boss of the driven-side movable
pulley half and the output shaft.
7. The V-belt continuously variable transmission as claimed in claim 6, wherein
the driven-side stopper is provided between the boss of the driven-side movable
pulley half and a slide collar of the driven-side stationary pulley mounted to the
output shaft.

8. The V-belt continuously variable transmission as claimed in claim 7, wherein
the driven-side stopper is provided between the boss of the driven-side movable
pulley half and an outer end of the slide collar.
9. The V-belt continuously variable transmission as claimed in claim 8, wherein
the driven-side stopper comprises an outer end surface of the boss of the driven-
side movable pulley half and a spring bearing member for the spring, fixed to the
outer end of the slide collar.

10. The V-belt continuously variable transmission as claimed in claim 5, wherein
the driven-side stopper comprises an outer end surface of a boss of the driven-
side movable pulley half and a spring bearing member for the spring, fixed to the
output shaft.
11. The V-belt continuously variable transmission as claimed in claim 5, wherein
the driven-side movable pulley half is made axially movable and rotatable with
the output shaft by engaging a guide pin, which is implanted in the output shaft,
with a slide groove on the driven-side movable pulley half, and the driven-side
stopper comprises the slide groove on the driven-side movable pulley half and
the guide pin.
12. The V-belt continuously variable transmission as claimed in claim 3 or 4,
wherein the drive-side stopper is provided between the drive-side movable pulley
half and the input shaft.

13. The V-belt continuously variable transmission as claimed in claim 12,
comprising a weight provided between the drive-side movable pulley and a cam
plate mounted to the input shaft to move radially outward to move the drive-side
movable pulley, and wherein the drive-side stopper is formed by restricting a
radial position of the weight.
14. The V-belt continuously variable transmission as claimed in claim 13, wherein
the drive-side stopper comprises a stopper portion formed on an outer edge of
the drive-side movable pulley half and the weight.
Dated This 22nd day of February 2005

This invention relates to a V belt continuously variable transmission constituted
by coupling a drive pulley 55, which is mounted on a crankshaft (input shaft) 28,
and a driven pulley 56, which is mounted on a transmission shaft (output shaft)
47, with a V belt 57, when a driven side variable pulley half body 56b of the
driven pulley 56 moves to a top time position where a winding diameter is
minimized, a boss portion 63 of the driven side movable pulley half body 56b is
brought into abutment against a spring bearing member 65, whereby the driven
side movable pulley half body 56b is regulated to the top time position.

Documents:

233-KOLNP-2005-(12-10-2011)-CORRESPONDENCE.pdf

233-KOLNP-2005-(12-10-2011)-OTHERS.pdf

233-KOLNP-2005-(12-10-2011)-PA.pdf

233-KOLNP-2005-(27-01-2012)-CORRESPONDENCE.pdf

233-KOLNP-2005-(27-01-2012)-FORM 27.pdf

233-KOLNP-2005-(27-01-2012)-PA.pdf

233-KOLNP-2005-FOR ALTERATION OF ENTRY.pdf

233-kolnp-2005-granted-abstract.pdf

233-kolnp-2005-granted-claims.pdf

233-kolnp-2005-granted-correspondence.pdf

233-kolnp-2005-granted-description (complete).pdf

233-kolnp-2005-granted-drawings.pdf

233-kolnp-2005-granted-examination report.pdf

233-kolnp-2005-granted-form 1.pdf

233-kolnp-2005-granted-form 13.pdf

233-kolnp-2005-granted-form 18.pdf

233-kolnp-2005-granted-form 2.pdf

233-kolnp-2005-granted-form 3.pdf

233-kolnp-2005-granted-form 5.pdf

233-kolnp-2005-granted-pa.pdf

233-kolnp-2005-granted-reply to examination report.pdf

233-kolnp-2005-granted-translated copy of priority document.pdf

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Patent Number

226435

Indian Patent Application Number

233/KOLNP/2005

PG Journal Number

51/2008

Publication Date

19-Dec-2008

Grant Date

17-Dec-2008

Date of Filing

22-Feb-2005

Name of Patentee

YAMAHA HATSUDOKI KABUSHIKI KAISHA

Applicant Address

2500 SHINGAI, IWATA-SHI, SHIZUOKA

Inventors:

#	Inventor's Name	Inventor's Address
1	YOUSUKE ISHIDA	C/O YAMAHA HATSUDOKI KABUSHIKI KAISHA, 2500 SHIGAI, IWATA-SHI, SHIZUOKA 438-8501

PCT International Classification Number

F16H 9/18

PCT International Application Number

PCT/JP2003/007238

PCT International Filing date

2003-06-06

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2002-327181	2002-11-11	Japan