JP4795182B2 - Motorcycle - Google Patents

Description

  The present invention relates to a shaft drive type motorcycle that changes rotational power from an engine with a transmission and transmits an output from the transmission to a rear wheel via a drive shaft.

In motorcycles, it is common to change the rotational power from the engine with a transmission and transmit the output from the transmission to the rear wheels with a chain. There is a shaft drive type that transmits power (see, for example, Patent Document 1). In the shaft drive type motorcycle, the rotational power of the output shaft of the transmission is transmitted to the drive shaft via the bevel gear, and the rotational power of the drive shaft is transmitted to the rear wheel via the bevel gear. According to this shaft drive type, there is an advantage that it is not necessary to adjust the elongation due to long-term use as in the case of a chain or to frequently lubricate, and the driving efficiency is also improved.
Japanese Patent Laid-Open No. 9-109981

  However, in the motorcycle disclosed in Patent Document 1, since the drive shaft extending in the longitudinal direction of the vehicle body from the transmission to the rear wheel is disposed horizontally, the output shaft of the transmission connected to the drive shaft is provided at a low position. The height is approximately the same as the axle of the rear wheel. In this case, the transmission is arranged at a position close to the ground, and the bank angle of the motorcycle when the vehicle body is inclined like cornering may be small.

  Therefore, an object of the present invention is to provide a shaft drive type motorcycle that can secure a sufficient bank angle.

The present invention has been made in view of the above circumstances, and a motorcycle according to the present invention transmits rotational power from an engine to a transmission via a clutch, and outputs from the transmission via a drive shaft. A shaft drive type motorcycle for transmitting to the rear wheel, wherein the drive shaft is disposed in the longitudinal direction of the vehicle body between the output shaft of the transmission and the axle of the rear wheel. Rotational power is transmitted to the drive shaft through a cam damper having a buffering function, and the cam damper is arranged to protrude outward in the vehicle width direction from the transmission case, and the drive shaft is rearward It is inclined obliquely downward toward the said output shaft Is provided with an extension shaft that protrudes outward in the vehicle width direction from the case, and the rotational power of the output shaft is transmitted to the extension shaft via the cam damper, and the rotational power of the extension shaft is driven by a bevel gear. It is transmitted to the drive shaft through .

  If it does in this way, since the front end part of a drive shaft is provided in a position higher than the rear end part, the output shaft of a transmission is provided in a position higher than the axle of a rear wheel. That is, by setting the position of the output shaft high, the transmission can be provided at a high position away from the ground. Therefore, a sufficient bank angle can be secured even when the vehicle body is tilted such as cornering.

The extension shaft and the bevel gear may be covered with a cover separate from the case, and the cover may rotatably support the extension shaft .

  In this way, if a cover that is separate from the transmission case is replaced, a chain connection structure is provided at one end of the output shaft instead of the bevel gear, and another cover is attached, the chain drive type motorcycle can also be used. The transmission can be shared, and the versatility of the transmission is improved.

The drive shaft has a spline connection, the to stretch the previous SL drive shaft the spline connection is slid in the axial direction in accordance with the distance variation between the output shaft and the rear wheel during traveling It may be a configuration.

  In the present invention, since the drive shaft is inclined obliquely downward toward the rear, when the rear wheel strokes up and down, for example, by traveling on an uneven road surface, the distance varies between the output shaft of the transmission and the axle of the rear wheel. Will occur. However, with the above-described configuration, the drive shaft expands and contracts at the spline connecting portion, and even if a variation in distance occurs between the output shaft of the transmission and the axle of the rear wheel, it can be absorbed by the spline connecting portion. it can.

  The spline connecting portion includes an outer cylindrical portion having spline teeth formed on an inner peripheral surface, and an inner shaft portion having spline grooves inserted in the outer cylindrical portion and slidably engaged with the spline teeth formed on the outer peripheral surface. The outer cylinder part may be provided with a guide part that slidably adheres to and covers the outer peripheral surface of the inner shaft part that continues in the axial direction of the spline groove.

  In this case, the spline connecting portion is normally set to have a backlash for sliding the inner shaft portion into the outer tube portion to be connected to the spline, but the outer periphery continues in the axial direction of the spline groove of the inner shaft portion. Since the surface is tightly covered with the guide portion of the outer cylinder portion, the backlash of the inner shaft portion with respect to the outer cylinder portion is reduced, and the rotational stability of the drive shaft is improved.

  An annular recess may be formed on the outer peripheral surface of the inner shaft portion covered with the guide portion, and a sealing material made of an elastic material that contacts the guide portion may be accommodated in the annular recess.

  If it does in this way, the shakiness with respect to the outer cylinder part of an inner shaft part will be absorbed by the sealing material which consists of elastic materials, and the rotational stability of a drive shaft will further improve. Further, even if the lubricating oil is supplied to the meshing portion between the spline teeth and the spline groove, it is sealed by the sealing material and is prevented from leaking from the front end opening of the outer cylinder portion.

  As apparent from the above description, according to the present invention, since the drive shaft is inclined obliquely downward toward the rear, the output shaft of the transmission is provided at a position higher than the axle of the rear wheel. It can be arranged above the vehicle body. Therefore, it is possible to secure a sufficient bank angle when the vehicle body is tilted.

  Embodiments according to the present invention will be described below with reference to the drawings. In addition, the concept of the direction used in the following description is based on a direction viewed from a driver (not shown) riding on the motorcycle 1.

  FIG. 1 is a side view of a motorcycle 1 according to an embodiment of the present invention. As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 and a rear wheel 3, and the front wheel 2 is rotatably supported by a lower end portion of a front fork 4 that extends substantially in the vertical direction. It is supported by a steering shaft (not shown) via an upper bracket (not shown) provided at the upper end portion and an under bracket provided below the upper bracket. The steering shaft is rotatably supported by the head pipe 5. A bar-type steering handle 6 extending to the left and right is attached to the upper bracket. Therefore, the driver can turn the front wheel 2 in a desired direction with the steering shaft as a rotation axis by rotating the steering handle 6. A fuel tank 7 is provided behind the steering handle 6, and a seat 8 for riding a driver is provided behind the fuel tank 7.

  A main frame 9 extends rearward from the head pipe 5 while being slightly inclined downward, and a pivot frame 10 is connected to a rear portion of the main frame 9. Between the front wheels 2 and the rear wheels 3, a parallel four-cylinder engine E is mounted in a state supported by the main frame 9 and the pivot frame 10. A cowling 11 is provided so as to cover the engine E and the like from the front of the vehicle body to both sides of the vehicle body.

  The engine E is integrally provided with a transmission 12. A front end portion of the drive shaft 14 is connected to the output shaft 13 of the transmission 12 via bevel gears 42 and 43 (see FIG. 2) described later. A rear end portion of the drive shaft 14 is connected to a rear gear case 15 connected to the axle 16 of the rear wheel 3. A swing arm 17 and a torque rod 18 are suspended in parallel between the pivot frame 10 and the rear gear case 15 in the vertical direction.

  The swing arm 17 is integrally formed with a shaft case portion 17 a that houses the drive shaft 14 and has a side opening, and the side opening of the shaft case portion 17 a is closed by a shaft cover 19. Further, the rear end of the shaft case portion 17a is connected to the rear gear case 15 via a rubber bellows cylindrical body 20.

  The pivot frame 10 has a recessed portion 10a that is recessed toward the center in the vehicle body width direction, and the front end portion of the drive shaft 14 is inserted into a space formed by closing the recessed portion 10a with the frame cover 21. Yes. A step 22 is fixed to the frame cover 21 as a footrest for the driver. Further, the other end portion (front end portion) of the rear frame 23 whose one end portion (rear end portion) is connected to a seat rail (not shown) that supports the seat 8 intersects the outer side of the torque rod 18 in the vehicle body width direction. The frame cover 21 is fixed.

  FIG. 2 is a sectional view of the motorcycle 1 shown in FIG. As shown in FIG. 2, the engine E is integrated by the same crankcase 26 as the transmission 12. The engine E is a parallel four-cylinder engine and has a crankshaft 27 that is rotatably supported by a crankcase 26. A generator 28 is attached to the left end of the crankshaft 27 and is covered with a generator cover 29. The transmission 12 includes an input shaft 33 arranged in parallel behind the crankshaft 27, an output shaft 13 arranged in parallel behind the input shaft 33, a plurality of transmission gears 34 provided on the shafts 13 and 33, A shift fork 35 is provided.

  A first gear (output gear) 30 is integrally provided on the crankshaft 27 of the engine E, and a second gear (input gear) 31 is rotatably provided on the input shaft 33. A wet multi-plate clutch 32 is provided at the right end of the input shaft 33 adjacent to the right side of the second gear 31. Then, the power from the first gear 30 is transmitted to the second gear 31, and transmission / cutoff of the power to the input shaft 33 is performed by the clutch 32, and the rotational power of the input shaft 33 is output to the output shaft via the transmission gear 34. 13 is transmitted. These show known transmissions.

  The left end portion of the output shaft 13 protrudes leftward from the crankcase 26. An extension shaft 36 is connected to the left end portion of the output shaft 13 via a needle bearing 37 so as to be rotatable on substantially the same axis. The rotational power of the output shaft 13 is transmitted to the extension shaft 36 via a cam damper 41 having a buffer function. The cam damper 41 includes a cam face member 38 splined to the output shaft 13, a cam follower member 39 splined to the extension shaft 36 and facing the cam face member 38, and the cam follower member 39 attached to the cam face member 38 side. And a compression coil spring 40 for energizing.

  A first bevel gear 42 is spline-connected to the extension shaft 36, and a second bevel gear 43 that converts the rotational axis 90 ° rearward is engaged with the first bevel gear 42. A support ring 45 is externally fitted to the second bevel gear 43 by spline connection. A screw hole is formed in the second bevel gear 43 in the axial direction from its rear end surface, and a support ring 45 is held by screwing a bolt 46 into the screw hole. A short first shaft portion 47, which is a part of the drive shaft 14, is externally fixed to the support ring 45 by spline connection. That is, power is transmitted from the second bevel gear 43 to the first shaft 47 via the support ring 45. A long second shaft portion 50 is connected to the rear end portion of the first shaft portion 47 via a first universal joint 49 to drive the rear wheel 3 (see FIG. 3). The support ring 45 and the first shaft 47 are connected and fixed by a pin 48.

  Then, the cover 44 is provided on the left side surface of the crankcase 26 so as to cover a portion exposed to the outside from the crankcase 26 (the left end portion of the output shaft 13, the cam damper 41, the first bevel gear 42, the second bevel gear 43, etc.). It is attached separately. The cover 44 rotatably supports the extension shaft 36 via the ball bearing 52 and also rotatably supports the second bevel gear 43 via the tapered roller bearings 54 and 54. An oil seal 53 is interposed between the support ring 45 and the cover 44. Further, an opening 44 a is formed in the cover 44 at a position corresponding to the extension shaft 36, and the opening 44 a is closed by a cap 51.

  FIG. 3 is a cross-sectional view of the motorcycle shown in FIG. As shown in FIG. 3, a short third shaft portion 61 (inner shaft portion) is connected to the rear end portion of the second shaft portion 50 of the drive shaft 14 via a second universal joint 60. An outer cylinder portion 62 is slidably fitted by spline connection at the rear end portion of the third shaft portion 61 to form a spline connection portion 85. As described above, the first shaft portion 47 (FIG. 2), the first universal joint 49 (FIG. 2), the second shaft portion 50, the second universal joint 60, the third shaft portion 61, and the outer cylinder portion 62 serve as the drive shaft. 14 is configured. Further, the third shaft portion 61 and the outer cylinder portion 62 are inserted into the rear gear case 15.

  A third bevel gear 64 disposed on substantially the same axis is splined to the rear end portion of the outer tube portion 62. The third bevel gear 64 is pivotally supported on the rear gear case 15 via a ball bearing 82. The third bevel gear 64 is engaged with an annular fourth bevel gear 65 that converts the rotation axis by 90 ° toward the axle 16. The fourth bevel gear 65 is supported by an inner cover 68 via a ball bearing 67, and a hub 71 is press-fitted and fixed to the inner peripheral portion of the fourth bevel gear 65. The hub 71 is rotatably attached to the rear gear case 15 via a needle bearing 66 at the left end thereof. The rear wheel 24 is coupled to the right end portion of the hub 71 via a spline connecting portion 69. The rear wheel 24 is rotatably fitted on the axle 16 via a ball bearing 70, and the rear wheel 3 (tire) is mounted.

  4 is an enlarged cross-sectional view mainly in the vicinity of the spline connecting portion 85 of FIG. As shown in FIG. 4, the third shaft 61 (inner shaft portion) includes a spline groove 61a formed on the outer peripheral surface on the rear end side, and a smooth outer peripheral surface 61b continuous on the front side in the axial direction of the spline groove 61a. And an annular recess 61c that is recessed in the circumferential direction at a part of the outer peripheral surface 61b, and a spring accommodating chamber 61d that is recessed so as to open to the rear end surface. A compression coil spring 63 is disposed in the spring accommodating chamber 61 d of the third shaft portion 61, and the compression coil spring 63 is supported by a spring seat 81 attached to the front end portion of the third bevel gear 64.

  The outer cylinder portion 62 is a guide that covers the spline teeth 62a that are slidably engaged with the spline grooves 61a of the third shaft portion 61 in the axial direction and the outer peripheral surface 61b on the front side of the third shaft portion 61 so as to be slidably adhered. And a spline tooth 62c provided at the rear end so as to be spline-connected to the third bevel gear 64. The length of the guide portion 62b in the axial direction is set to 0.5 times or more, preferably 0.8 times or more, of the length of the spline teeth 62a in the axial direction. The outer cylindrical body 62 is rotatably supported by the intermediate cylindrical body 84 via the oil seal 83, and the intermediate cylindrical body 84 is screwed to the cylindrical portion 15 a of the rear gear case 15.

  The wall surface on the rear end side of the outer cylindrical portion 62 is formed with an oil hole 62d that communicates the internal spline space S1 having the spline teeth 61a with the external gear case space S2 in which the bearing 82 and the oil seal 83 are disposed. Has been. And the rubber | gum O-ring (sealing material) 80 is accommodated in the annular recessed part 61c of the 3rd shaft part 61 so that the guide part 62b may be contacted. Therefore, the oil that lubricates the bearing 82 and the bevel gears 64 and 65 in the rear gear case 15 also lubricates the spline teeth 62a and the spline grooves 61a through the oil holes 62d of the outer cylindrical portion 62, and the oil by the O-ring 80. To prevent leakage.

  With the above configuration, as shown in FIG. 1, since the front end portion of the drive shaft 14 is provided at a position higher than the rear end portion thereof, the output shaft 13 of the transmission 12 is positioned higher than the axle 16 of the rear wheel 3. Provided. That is, by setting the position of the output shaft 13 high, the transmission 12 can be provided at a high position away from the ground. Therefore, a sufficient bank angle can be secured even when the vehicle body is tilted such as cornering.

  Further, as shown in FIG. 2, the cover 44 covering the left end portion of the output shaft 13, the extension shaft 36, the cam damper 41, the first bevel gear 42, the second bevel gear 43 and the like is provided separately from the crankcase 26. ing. Therefore, if the cover 44 or the like is replaced and a chain connection structure is provided at the left end portion of the output shaft 13, the chain drive type motorcycle can also be used as the transmission 12, and versatility is improved.

  Further, as shown in FIG. 4, the third shaft portion 61 and the outer cylinder portion 62 can slide relative to each other in the axial direction, so that the drive shaft 14 can be expanded and contracted by a spline connecting portion 85. . Therefore, even if the rear wheel 3 strokes up and down while the drive shaft 14 is inclined obliquely downward toward the rear as in the present invention, the drive shaft 14 expands and contracts at the spline connecting portion 85, and the transmission The distance fluctuation between the 12 output shafts 13 and the axle 16 of the rear wheel 3 can be absorbed.

  The spline connecting portion 85 is usually provided with play for slidingly inserting the third shaft portion 61 into the outer cylindrical portion 62 to be connected to the spline connecting portion, but the guide portion 62b of the outer cylindrical portion 62 is third. Since the outer peripheral surface 61b of the shaft 61 is tightly covered, backlash is reduced and the rotational stability of the drive shaft 14 is improved.

  Further, since the O-ring 80 that comes into contact with the guide part 62b of the outer cylinder part 62 is accommodated in the annular recess 61d of the third shaft part 61, there is a backlash between the third shaft part 61 and the outer cylinder part 62. Is further absorbed by the O-ring 80, and oil leakage from the front end opening of the outer cylindrical portion 62 is prevented. The motorcycle of the present invention is not limited to the embodiment described above, and the configuration can be changed, added, or deleted without departing from the spirit of the present invention.

  As described above, the motorcycle according to the present invention has an excellent effect of ensuring a sufficient bank angle, and can be widely applied to a shaft drive type motorcycle that can exhibit the significance of this effect.

1 is a side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the motorcycle shown in FIG. 1 as viewed mainly from the vicinity of the transmission. FIG. 2 is a cross-sectional view of the motorcycle shown in FIG. 1 as viewed from above mainly in the vicinity of a rear wheel. FIG. 4 is an enlarged cross-sectional view mainly in the vicinity of a spline connection portion in FIG. 3.

DESCRIPTION OF SYMBOLS 1 Motorcycle 3 Rear wheel 12 Transmission 13 Output shaft 14 Drive shaft 16 Axle 36 Extension shaft 42 1st bevel gear 43 2nd bevel gear 44 Cover 61 3rd shaft part (inner shaft part)
61a Spline groove 61b Outer peripheral surface 61d Annular recess 62 Outer cylindrical part 62a Spline tooth 62b Guide part 80 O-ring (seal material)
85 Spline connection E Engine

Claims (3)

A shaft drive type motorcycle that transmits rotational power from an engine to a transmission through a clutch and transmits output from the transmission to a rear wheel through a drive shaft,
The drive shaft is disposed in the vehicle longitudinal direction between the output shaft of the transmission and the axle of the rear wheel,
Rotational power of the output shaft is transmitted to the drive shaft via a cam damper having a buffer function, and the cam damper is disposed so as to protrude outward in the vehicle width direction from the case of the transmission.
The drive shaft is inclined obliquely downward toward the rear ,
The output shaft is provided with an extension shaft that protrudes outward in the vehicle width direction from the case,
The motorcycle according to claim 1, wherein the rotational power of the output shaft is transmitted to the extension shaft via the cam damper, and the rotational power of the extension shaft is transmitted to the drive shaft via a bevel gear . The motorcycle according to claim 1 , wherein the extension shaft and the bevel gear are covered with a cover separate from the case, and the cover rotatably supports the extension shaft.   The drive shaft has a spline connecting portion, and the drive shaft expands and contracts by sliding the spline connecting portion in the axial direction in accordance with a change in distance between the output shaft and the rear wheel during traveling. Item 3. The motorcycle according to item 1 or 2.

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