Title of Invention

"GENERATOR MOUNTING STRUCTURE FOR ENGINE"

Abstract

[Problem] A generator mounting construction, for engine enables to easily secure the concentric position of a stator with respect to a crank shaft by applying a positioning collar with thin thickness, and the press fitting work can be eliminated. [Solving Means] A rotor 15 is fixed to a shaft portion 4 extended outwardly from the journal of the crank shaft S, and a stator 16 is bolt-jointed to the end surface of a fixed boss 10 which is formed in a crank case C and surrounds concentrically the shaft portion 4 outwardly extended from the journal. In such arrangements, a positioning collar 27 is fitted engageably and disengageably to both inner circumferential surfaces of the stator 16 and the fixed boss 10, and between the stator 16 and the fixed boss 10, a clip 29 is provided at the outer circumferential surface of the positioning collar 27 to restrain the axial movement of the positioning collar 27.

Full Text

The subject invention relates to a generator mounting Structure for an engine [Technical Field of the Invention] This invention relates to a generator mounting construction for an engine, and more particularly to an improvement for the generator mounting construction wherein the rotor is fixed to the shaft portion outwardly extended from the journal of the crank shaft, and the stator disposed in a rotor is fixed to the end surface of the fixed boss which surrounds the external shaft portion of said journal concentrically, and is formed in a crank case which supports a crank shaft. [Prior Art] According to the conventional type of such generator mounting construction as disclosed in the Japanese Patent Laid Open No 8-154354,one axial half of the positioning Collar is press fitted into the inner surface of the stator, while the other portion is fitted firmly into the inner surface of the fixing boss so that the concentricity of the stator with respect to the crank shaft can be designated. [Problem to be Solved by the Invention] According to the above described generator mounting construction to overcome the stress of the positioning collar during press fitting to the stator, said collar shall be formed with substantially large thickness, and to secure the better press fitting, the dimension of the press fitted portion must be precisely engineered, and also takes the laborious work of press fitting machine, thereby, it is difficult to cost down. The purpose of this invention is to provide a generator mounting construction for engine to enable the concentricity of the stator with respect to the crank shaft to be simply, securely designated without the press fitting work, by applying the thin positioning collar, and yet to cost down. [Means for Solving the Problems] To achieve the above purpose, in the generator mounting construction wherein the rotor is fixed to the shaft portion outwardly extended from the journal of the crank shaft, and the stator disposed in a rotor is fixed to the end surface of the fixed boss which surrounds the external portion of said journal concentrically and is formed in a crank shaft which supports a crank shaft, a positioning collar is fitted engageably and disengageably to both inner circumferential surfaces of the stator and the fixed boss at the outer circumferential surface of the axially mid-position of the positioning collar, and a collar which restrains the axial movement of the positioning collar is provided between the stator and the fixed boss, and this is the first characteristic of the present invention. According to this characteristic, the application of the positioning collar to the fixed boss and to the stator is easily secured without depending on the press fitting machine, and further the stator can be positioned concentrically with respect to the crank shaft. Yet the positioning collar is free from the big load from the fixed boss and the stator core, thereby, the thinner positioning collar can be formed which results in the less total weight . According to the present invention, in addition to the above characteristics, said collar is disposed in the annularly arranged chamfer section formed at the inner circumferential surface of the fixed boss and both end surfaces of the stator and the fixed boss are positioned in abutting condition, and an oil seal fixed to the inner circumferencial surface of the fixed boss being guided into the said chamfered section is provided therein, and the outer end surface of the oil seal is in conf ronting'condition with the positioning collar, and this is the second characteristic of the present invention. Further, the chamfered section of the fixed boss enables to securely position the collar portion of the positioning collar, and to contact with the end surface of the fixed boss designated to fix the stator, thereby, the stator can be correctly fixed to the end surface of the fixed boss without tilting the stator. Further, the chamfered section can work as the guide to secure the oil seal in the fixed boss, thus the oil seal can be easily and securely * installed. Further, the positioning collar is effective to prevent the oil seal from being detached. Accordingly, the present invention relates to a generator mounting structure for an engine wherein a rotor (15) is fixed to a shaft portion (4) extended outwardly from the journal of a crank shaft (S), and a stator (16) disposed in the rotor (15) is fixed to the end surface of a fixed boss (10) which surrounds concentrically the shaft portion (4) extended outwardly from the journal and is formed in a crank case (C) which supports a crank Shaft (S) characterized in that a positioning collar (27) is fitted engageably and disengageably to the inner circumferential surfaces of the stator (16) and the fixed boss (10) and at the outer circumferential surface of the axially mid-position portion of the positioning collar (27), a collar (29,37) which positions between the stator (16) and the fixed boss (10) and restrains the axial movement of the positioning collar (27) is provided. [Brief Description of the ACCOMPANYING Drawings] (Fig.I] Vertical sectional view of a motorcycle engine with a generator mounted thereon related tothe embodiments of the present invention. [Fig.2] Enlarged view of the circled area 2 of Fig.l. [Fig.3] Another embodiment view similar to Fig.2. [Preferred Embodiments] One embodiment of the present invention will be explained referring to the accompanying drawings hereinafter. Fig.l is a partial drawing of a motorcycle engine, and symbol S denotes a crank shaft of the engine, C denotes a crank case, and G denotes a generator installed therein. A journal 1 of the crank shaft S is supported in the crank case C by virtue of a roller bearing 3 installed in a bearing housing 2. The crank shaft S provides a shaft portion 4 outwardly extended from the journal 1, and along the journal 1 to the distal end, a screw gear 5 for pumping oil, a straight portion 6 whose diameter is shorter than the screw gear, a much tapered portion 7, a less tapered portion 8, and a thread portion 9 are formed and aligned in succession. Besides, at the side wall of the crank case S, a fixed boss 10 which surrounds the shaft portion 4 outwardly extended from the journal along the screw gear 5 to the much tapered portion 7 is formed integrally. The inner circumferential surface of the fixed boss 10 is concentrically formed with respect to the shaft portion 4 outwardly extended from the journal, and an annular chamfered portion 11 is formed along the inner circumferential surface of the fixed boss. At the outer circumferential surface of the straight portion 6, an oil seal 12 which contacts seal lips sealingly is slightly fitted being guided by the chamfered portion 11 to the inner circumferential surface of the fixed boss 10 is concentrically formed with respect to the shaLt portion 4 outwardly extended from the journal. A plurality of screw holes are provided on the end surface of the fixed boss 10. (Only one screw hole 13 is shown in the drawing.) A generator G comprises a rotor 15 shaped cylindrically with a bottom surface, and a stator 16 disposed at the inner side of the rotor, and the rotor 15 comprises a plurality of magnets 18 arranged annularly at the inner circumferential surface of the rotor body 17 shaped cylindrically with a bottom surface. At the center of the end wall of the rotor body 17, a boss 17a is connected in caulking condition, and the boss 17a is fitted to the less tapered section 8 by virtue of key 19, and is fixed by a nut 20 which engages with the thread 9. The stator 16 comprises a disc-shaped stator core 22 which provides a central hole 22a whose diameter is almost same as the diameter of the inner circumferential surface of the fixed boss 10 and a stator coil 24 disposed at the both sides of the stator core 22 by virtue of a bobbin 23. The stator core 22 provides a plurality of bolt holes 25 (Only one bolt hole 25 is shown in the drawing) inside the stator coil 24, and a bolt 26 is inserted into the bolt hole 25 so that it engages with the threaded hole 13 of the fixed boss 10 and thus the stator core 22 can be connected to the end surface of the fixed boss 10. Before this connection work, the stator core 22 can be positioned concentrically with respect to the crank shaft S by the positioning collar 27 as the following description explains. Referring to Fig 2, the positioning collar 27 provides the portions defined as one axial direction and the other axial direction which engage and disengage with the inner circumferential surfaces of the fixed bosslO and the stator core 22, and an annular groove 28 is so formed at the outer circumferential surface of the positioning collar 27 that divides the two portions, and an annular clip 29 is engaged with the annular groove 28, and the annular clip 29 configures as the collar of the present invention. Portions of the positioning collar 27 defined as one axial direction and the other axial direction are fitted to the inner circumferential surfaces of the fixed boss 10 and the stator core 22, thus the concentricity of the stator 16 with respect to the crank shaft S is designated, and since the clip 29 positions between the fixed boss 10 and the stator core 22, the movement of the positioning collar 27 in axial direction is restrained. In addition., since the clip 29 is wholly positioned in the chamfered section 11 of the fixed boss 10, the contact of the stator 22 to the end surface of the fixed boss 10 will not be loosened. Resultantly, the stator core 22 can be fixed correctly to the end surface of the fixed boss 10 without tilting the stator core 22. Since the positioning collar can be fitted engageably and disengageably into the inner circumferential surfaces at the fixed boss 10 and the stator core 22 , the installation of the positioning collar can be easily performed without the press fitting machine. In addition, the positioning collar 27 is free from the load from the fixed boss 10 and the stator core 22 and the thickness at the positioning collar 27 can be reduced so that the total weight can be reduced. Since the positioning collar 27 is positioned in confronting situation with the end surface of the oil seal 12 with a small space interposed there between, even if the oil seal 12 is moved outwardly in the fixed boss 10, the positioning collar 27 will prevent its movement. At the outer face of the rotor body 17, a .cooling fan 31 is fixed by a bolt 32, and surrounding this cooling fan 31, a shroud 34 with an air inlet 33 therein is fixed to the outer peripheral portion of the crank case C. At the outer circumferential surface of the rotor body 17 , several projections 35 are formed along its circumf erencial direction so that a sensor 36 which detects the approaching of the projections 35 is installed in the crank case C. The sensor 36 can send detection signals as the engine R.P.M. to a tachometer (not shown) . Fig. 3 illustrates another embodiment of the present invention, and in lieu of the clip 29, a flange 37 is formed integrally at the outer circumferential surface of the positioning collar 27, and this configuration is the only one difference from the first embodiment. The like numerals and symbols designate the corresponding parts of the first embodiment throughout. This invention is not limited to the above described embodiments, and many modified embodiments can be made without departing from the spirit and the scope thereof. [Effects of the Invention] According to the first embodiment of the present invention, the positioning collar is fitted to the inner circumferential surfaces of the stator and the fixed boss engageably and disengageably, and at the outer circumferential surface of the axially mid-position of the positioning collar, the collar is provided to restrain the axial movement of the positioning collar between the stator and the fixed boss, so that the attaching of the positioning collar to both the fixed boss and the stator can be easily securely performed, and the stator can be concentrically positioned with respect to the crank shaft, and since the positioning collar is free from the load, its thickness can be reduced so the less total weight and the cost down can be expected. According to the second embodiment of the present invention, the collar is disposed in the annular chamfered section formed at the inner circumferential surface of the fixed boss, and both end surfaces of the sator and the fixed boss are positioned in abutting condition, and the oil seal is guided in the chamfered section and is installed at the inner circumferential surface of the fixed boss, and the outer end surface of the oil seal is confronted with the positioning collar, so, by positioning the collar to the chamfered section, the stator can be fixed to the«end surface of the fixed boss correctly, and within the chamfered section, the oil seal can be installed in the fixed boss snugly. Further, the collar prevents the oil seal from being detached. {Description of the Reference Numerals] C Crank case G Generator S Crank shaft 4 Shaft portion extended from journal 10 Fixed boss 11 Chamfered section 12 Oil seal 15 Rotor 16 Stator 27 Positioning collar 29 Clip as a collar 37 Flange as a collar We claim: 1. A generator mounting structure for an engine wherein a rotor (15) is fixed to a shaft portion (4) extended outwardly from the journal of a crank shaft (S), and a stator (16) disposed in the rotor (15) is fixed to the end surface of a fixed boss (10) which surrounds concentrically the shaft portion (4) extended outwardly from the journal and is formed in a crank case (C) which supports a crank Shaft (S) characterized in that a positioning collar (27) is fitted engageably and disengageably to the inner circumferential surfaces of the stator (16) and the fixed boss (10) and at the outer circumferential surface of the axially mid-position portion of the positioning collar (27), a collar (29,37) which positions between the stator (16) and the fixed boss (10) and restrains the axial movement of the positioning collar (27) is provided. 2. A generator mounting structure for engine as claimed in claim 1, wherein said collar (29, 37) is disposed in a chamfered section (11) formed annularly at the inner periphery of the end surface of the said fixed boss (10) and confronting surfaces of the stator (16) and the fixes boss (10) are firmly contacted, and outer end surface of an oil seal (12) fixed to the inner circumferencial surface of the said fixed boss being guided into said chamfered section (11) is positioned to confront with the positioning collar (27). 3. A generator mounting structure for an engine substantially as hereinbefore described with the reference to and as illustrated in the foregoing description and accompanying drawings.

Documents:

3223-del-1997-abstract.pdf

3223-del-1997-claims.pdf

3223-del-1997-correspondence-others.pdf

3223-del-1997-correspondence-po.pdf

3223-del-1997-description (complete).pdf

3223-del-1997-drawings.pdf

3223-del-1997-form-1.pdf

3223-del-1997-form-13.pdf

3223-del-1997-form-19.pdf

3223-del-1997-form-2.pdf

3223-del-1997-form-3.pdf

3223-del-1997-form-4.pdf

3223-del-1997-form-6.pdf

3223-del-1997-gpa.pdf

3223-del-1997-petition-137.pdf

3223-del-1997-petition-138.pdf

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