Title of Invention

POWER TRANSFER DEVICE IN SMALL-SIZED VEHICLE

Abstract

A power transfer device in a small-sized vehicle in which a primary drive gear (8, 28) driven by a crank shaft is engaged with a primary driven gear (5, 25) rotatably attached to a transmission shaft (1, 21) to transmit power from power unit to a transmission, where in a starting clutch mechanism (10, 30) is arranged on the transmission shaft (1, 21), further a torque transmission mechanism is arranged at the primary driven gear (5, 25) characterized in that power from power unit is transmitted in series from the primary driven gear (5, 25) to the torque transmission mechanism which has the vibration isolating member (4, 24) between the input section (5, 25) and the output section (3, 35) and to the starting clutch mechanism (10, 30) in this order.

Full Text

FORM 2 THE PATENTS ACT 1970 [39 OF 1970] & THE PATENTS RULES, 2003 COMPLETE SPECIFICATION [See Section 10; rule 13] "POWER TRANSFER DEVICE IN SMALL-SIZED VEHICLE" HONDA GIKEN KOGYO KABUSHIKI KAISHA, a corporation of Japan, 1-1, Minamiaoyama 2-chome, Minato-ku, Tokyo, Japan, /'. The following specification particularlyi describes the invention and the manner in which it is to be performed: [Detailed Description of the Invention] [Technical Field to Which the Invention Pertains] The present invention relates to a power transfer device in a vehicle, especially a small-sized vehicle. [Prior Art] As a conventional power transfer device in a vehicle there is known, for example, one disclosed in Japanese Utility Model Laid-open No. Sho 63-59260. Fig. 4 is a side view in vertical section, showing an example of such a conventional power transfer device in a vehicle. In Fig. 4, the numeral 01 denotes a crank shaft, to which is splined a clutch inner 03 of a starting clutch 02 unrotatably. A clutch weight 04 is pivotally connected to the clutch inner 03. As the rotational speed of the crank shaft 01 increases, the clutch weight 04 is pushed against a clutch outer 05 by virtue of a centrifugal force, so that the rotation of the crank shaft 01 is transmitted to the clutch outer 05, that is, the starting clutch 02 is engaged. 2 A primary drive gear 06 is mounted around the crank shaft 01 rotatably and the clutch outer 05 is fixed to the primary drive gear 06. Therefore, when the starting clutch 02 is engaged, the primary drive gear 06 also rotates. On the other hand, a primary driven gear center 012 is mounted rotatably onto a transmission shaft 011 which is parallel to the crank shaft 01, and a primary driven gear 014 is connected to the primary driven gear center 012 so as to permit a slight relative rotation through a vibration isolating member 013. The primary driven gear 014 is in mesh with the primary drive gear 06. Numeral 021 denotes a multiple disc clutch. A clutch outer 022 of the multiple disc clutch 021 is formed integrally with the primary driven gear center 012. A clutch inner 023 is splined to the transmission shaft 011. Numeral 024 denotes a clutch engaging/releasing mechanism. With the starting clutch 02 engaged, the primary drive gear 06 is in a rotating state, which rotation is transmitted to the primary driven gear center 012 via the 3 primary driven gear 014 meshing with the primary drive gear 06, causing the clutch outer 022 to rotate. When the multiple disc clutch 021 is engaged by the clutch engaging/releasing mechanism 024, the clutch inner 023 rotates and the transmission shaft 011 also rotates. [Problems to be Solved by the Invention] In the above conventional power transfer device in a vehicle, the starting clutch 02 is not provided with a buffer mechanism, so it is impossible to effectively prevent vibration of the starting clutch 02 which vibration is caused by a change in input torque, and the starting clutch is not smoothly brought into its engaged state. [Means for Solving the Problems and Effects] For solving the above-mentioned problems involved in the prior art, according to the invention defined in claim 1 there is provided a power transfer device in a small-sized vehicle characterized in that a starting clutch mechanism and an input torque buffer mechanism are disposed on a transmission shaft, and power from a power unit is transmitted in series through the input torque buffer mechanism and the starting clutch mechanism in 4 this order. Since the invention defined in claim 1 is constructed as above, a rotational power from the power unit is transmitted in series through the input torque buffer mechanism and the starting clutch mechanism in this order, so that a change in input torque is diminished by the input torque buffer mechanism prior to transmission to the starting clutch mechanism and vibration is absorbed, whereby the starting clutch mechanism is engaged smoothly. According to the invention defined in claim 2 there is provided, in combination with the invention defined in claim 1, a power transfer device in a small-sized vehicle wherein a support member for supporting a vibration isolating member in the input torque buffer mechanism and a clutch inner in the starting clutch mechanism are coupled together on the transmission shaft. Since the invention defined in claim 2 is constructed as above, it. is possible to ensure a sufficiently large width of a bearing member, so that an axial size can be reduced while inhibiting a -tilting 5 motion- of—a-rotary member- According to the invention defined in claim 3 there is provided, in combination with the invention defined in claim 1, a power, transfer device in a small-sized vehicle wherein the vibration isolating member is attached to a back side of a clutch inner plate which is integral with the clutch inner. Since the invention defined in claim 3 is constructed as above, not only the number of parts used and the weight of the device are reduced to a remarkable extent, but also the axial length is greatly shortened, thus contributing to the reduction of size. Further, the machining and assembling works become simpler and easier and the cost is reduced remarkably. 6 According to the present invention there is provided a power transfer device in a small-sized vehicle in which a primary drive gear driven by a crank shaft is engaged with a primary driven gear rotatably attached to a transmission shaft to transmit power from power unit to a transmission, where in a starting clutch mechanism is arranged on the transmission shaft, further a torque transmission mechanism is arranged at the primary driven gear characterized in that power from power unit is transmitted in series from the primary driven gear to the torque transmission mechanism which has the vibration isolating member between the input section and the output section and to the starting clutch mechanism in this order. [Brief Description of the Drawings] [Fig. 1] Fig.. 1 is a side view in vertical section showing an embodiment of the present invention. [Fig. 2] " Fig. 2 is a side view in vertical section (a sectional view as seen in the direction of arrows II - II in Fig. 3) showing another embodiment of the present invention. .[Fig. 3] Fig. 3 is".a sectional view as seen in the direction of arrows III - III in Fig. 2. [Pig. 4] Fig. 4 is a side view in vertical section showing an example of a conventional power 'transfer device in a . vehicle. 7 [Mode for Carrying Out the Invention] Fig. 1 is a side view in vertical section showing an embodiment of the present- invention. In the same figure, the numeral 1 denotes a transmission shaft on which is rnounted a boss portion 3a of a primary driven gear center 3 rotatably through a 8 metal bearing, i.e., bushing 2. To the primary driven gear center 3 is secured a primary driven gear 5 with a rivet 7 so as to permit a slight relative rotation through plural vibration isolating members 4 which are held grippingly by a plate portion 3b of the primary driven gear center and a driven gear side plate 6. The primary driven gear center 3, vibration isolating member 4, primary driven gear 5, driven gear side plate 6, and rivet 7 constitute an input torque buffer mechanism 9. Numeral 5a denotes a reduced wall portion of the primary driven gear 5. A primary drive gear 8, which is driven by a crank shaft (not shown), is in mesh with the primary driven gear 5. On the other hand, a clutch outer boss 11 in a starting clutch mechanism 10 is splined to the transmission shaft 1 unrotatably and a clutch outer 13 is fixed to the clutch outer boss 11 with a rivet 12. Further, a driven plate 14 is splined to an outer peripheral portion of the boss portion 3a of the primary driven gear center 3 and a clutch inner plate 15 is fixed to the driven plate 14. Thus, the primary driven gear center 3 as a support member for supporting the vibration isolating members 4 in the input torque buffer mechanism 9 and the clutch inner plate 15 in the starting clutch mechanism 10 are coupled together on the transmission shaft 1. Plural clutch weights 16 are pivotally supported by the clutch inner plate 15 through a clutch weight supporting shaft 17. Numeral 18 denotes a spring, which urges the clutch weights 16 in a direction in which the clutch weights are pulled apart from the clutch outer 13. A rotational power from the crank shaft (not shown) is transmitted from the primary drive gear 8 to the primary driven gear center 3 via the primary driven gear 5. In this connection, the primary driven gear 5 and the primary driven gear center 3 are coupled together so as to permit a slight relative rotation through the plural vibration isolating members 4; so when the engine torque transmitted from the primary drive gear 8 to the primary driven gear center 3 varies, the occurrence of a shock is diminished by deformations of the vibration isolating members 4. The rotation of the primary driven gear center 3 is transmitted to the clutch inner plate 15 via the driven plate 14. As a result, the clutch weights 16 are allowed to swing outwards against the biasing force of the spring 10 18 by virtue of a centrifugal force of the clutch weights 16, and when the rotational speed exceeds a certain limit, the clutch weights 16 are pushed against an inner surface of the clutch outer 13 and the starting clutch mechanism 10 assumes an engaged state, whereby the rotational power is transmitted to the transmission shaft 1 via the clutch outer 13 and the clutch outer boss 11. I0JL2JQ4—. In this embodiment the starting clutch mechanism 10 and the input torque buffer mechanism 9 are disposed on the same transmission shaft 1 and the rotational force from the power unit is transmitted in series through the input torque buffer mechanism 9 and the starting clutch mechanism 10 in this order, so that a change in input torque is diminished by the input torque buffer mechanism before transmitted to the starting clutch mechanism 10, and vibration is absorbed, thus permitting the starting clutch mechanism 10 to be engaged smoothly. [0021] In this embodiment, moreover, the driven plate 14 integral with the clutch inner plate 15 in the starting clutch mechanism 10 is splined to an outer peripheral portion of the boss portion 3a of the primary driven gear center 3 which is a support member for supporting the vibration isolating members 4 in the input torque buffer mechanism, and the primary driven gear center 3 and the clutch inner plate 15 are coupled together on the transmission shaft 1, so that it is possible to ensure a sufficiently large width of the bushing 2 as a bearing member and an axial length can be reduced while inhibiting a tilting motion of the rotary member on the transmission shaft 1. Next, Fig. 2 is a side view in vertical section (a sectional view as seen in the direction of arrows II - II in Fig. 3) showing another embodiment of the present invention and Fig. 3 is a sectional view as seen in the direction of arrows III - III in Fig. 2. In the figures, the numeral 21 denotes a transmission shaft, to which is splined a clutch outer boss 31 of a starting clutch mechanism 30 unrotatably, and a clutch outer 33 is welded to the clutch outer boss 31. A driven plate 34, which is integral with a clutch inner plate 35, is mounted on the transmission shaft 21 rotatably through a bushing 22. Plural clutch weights 3 6 are pivotally supported by the clutch inner plate 35 through a clutch weight supporting shaft 37. Further, a 12 spring 3 8 is provided to urge the clutch weights 3 6 in a direction in which the clutch weights are pulled apart from the clutch outer 33. On the other hand, plural (four in the illustrated embodiment) vibration isolating members 24 are attached to a back side of the clutch inner plate 35, and through the vibration isolating members 24 the clutch inner plate 35 and the primary driven gear 25 are coupled together by a driven gear side plate 26 and a rivet 27 so as to permit a slight relative rotation. Numeral 25a denotes a reduced wall portion of the primary driven gear 25 and a -head of the clutch weight supporting shaft 37 is received within the reduced wall portion 25a. A primary drive gear 28, which is driven by a crank shaft (not shown), is in mesh with the primary driven gear 25. A rotational power from the crank shaft (not shown) is transmitted from the primary drive gear 28 to the driven plate 34 and the clutch inner plate 35 via the primary driven gear 25 and the vibration isolating members 24. When the torque of a power unit varies, the occurrence of a shock is diminished by deformations of the vibration isolating members 24. This is the same as in the previous first embodiment. When the clutch inner plate 35 rotates, the clutch weights 36 are allowed to swing outwards against the biasing force of the spring 38 by virtue of a centrifugal force, as in the first embodiment. Then, the rotational speed exceeds a certain limit, the clutch weights 36 are pushed against an inner surface of the clutch outer 33, so that the starting clutch mechanism 30 assumes an engaged state, whereby the rotational power is transmitted to the transmission shaft 21 via the clutch outer 33 and the clutch outer boss 31. Also in this embodiment the starting clutch mechanism 30 and the input torque buffer mechanism are disposed on the same transmission shaft and the rotational power from the power unit is transmitted in series via the input torque buffer mechanism and the starting clutch mechanism 30 in this order, so that a change in input torque is, diminished by the input torque buffer mechanism before transmitted to the starting clutch mechanism 30, and vibration is absorbed, whereby the starting clutch mechanism 30 is engaged smoothly. 14 A comparison will now be made between this second embodiment and the previous first embodiment. In this second embodiment, the plate portion 3b of the primary driven gear center 3- in the first embodiment" (Fig: 1) is disposed close to the starting clutch mechanism 10 and serves also as the clutch inner plate 15. Further, the plate portion 3b of the primary driven gear center 3, the driven plate 14, and the clutch inner plate 15 are formed integrally to constitute the driven plate 34 and the clutch inner plate 35 both shown in Fig. 2. In this second embodiment, therefore, the driven plate 14 used in the first embodiment is not needed, nor is it necessary to perform machining for the spline connection between the driven plate 14 and the boss portion 3a of. the primary driven gear center 3. Besides, the number of parts used and the weight of the device are reduced to a remarkable extent. Further, an axial length is shortened greatly and the device size is reduced, resulting in that the machining and assembling works become simpler and easier and the cost is greatly reduced. 15 [Explanation of Reference Numerals] 1, 2l ....transminssion— shaf ts 2" "22 .... bushings 3 ... primary driven gear center; 3a ... boss portion; 3b ... plate portion; 4, 24 ... vibration isolating members; 5, 25 . .'. primary driven gears; 5a, 25a ... reduced wall, portions; 6, 26 ... driven gear side plates; 7, 27 ... rivets; 8, 28 ... primary drive gears; 9 ... input torque buffer mechanism; 10, 3 0 ... starting clutch mechanisms; 11, 31 ... clutch outer bosses; 1,2 ... rivet; 13, 33 ... clutch outers; 14, 34'... driven 16 We Claim: 1. A power transfer device in a small-sized vehicle in which a primary drive gear (8, 28) driven by a crank shaft is engaged with a primary driven gear (5, 25) rotatably attached to a transmission shaft (1, 21) to transmit power from power unit to a transmission, where in a starting clutch mechanism (10, 30) is arranged on the transmission shaft (1, 21), further a torque transmission mechanism is arranged at the primary driven gear (5, 25) characterized in that power from power unit is transmitted in series from the primary driven gear (5, 25) to the torque transmission mechanism which has the vibration isolating member (4, 24) between the input section (5, 25) and the output section (3, 35) and to the starting clutch mechanism (10, 30) in this order. 2. A power transfer device in a small-sized vehicle as claimed in claim 1, wherein a support member for supporting a vibration isolating member (4, 24) in said torque transmission mechanism and a clutch inner in said starting clutch mechanism (10) are coupled together on said transmission shaft (1). -18- 3. A power transfer device in a small-sized vehicle as claimed in claim 2, wherein said vibration isolating member is attached to a back side of a clutch inner plate (15) which is integral with said clutch inner. 4. A power transfer device substantially as herein described with reference to the accompanying drawings. Dated this the 8th day of October, 2001

Documents:

979-mum-2002-cancelled pages(28-11-2006).pdf

979-mum-2002-claims(granted)(28-12-2006).pdf

979-mum-2002-correspondence(1-12-2006).pdf

979-mum-2002-correspondence(ipo-)(7-9-2006).pdf

979-mum-2002-drawing(28-11-2006).pdf

979-mum-2002-form 1(30-4-2006).pdf

979-mum-2002-form 1(8-10-2001).pdf

979-mum-2002-form 18(7-10-2005).pdf

979-mum-2002-form 2(granted)-(28-12-2006).pdf

979-mum-2002-form 3(30-4-2006).pdf

979-mum-2002-form 3(8-10-2001).pdf

979-mum-2002-form 5(8-10-2001).pdf

979-mum-2002-pitition under rule 138(13-4-2006).pdf

979-mum-2002-power of authority(15-3-2002).pdf

979-mum-2002-power of authority(27-11-2006).pdf

979-mum-2002-power of authority(28-11-2006).pdf

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