JP2007302059A - Power transmission device for vehicle - Google Patents

Abstract

A reduction gear differential provided in a vehicle power transmission device is miniaturized.
A differential device having a pinion and a side gear for distributing rotational force to left and right axles in a differential case and having a differential input gear on the outer periphery thereof, and one cam on an end surface thereof are rotatably supported on an output shaft. An output gear that transmits the rotational force of the internal combustion engine to the differential input gear and is paired with the differential input gear to form a speed reducer, and has the other cam on the end face and is spline fitted to the output shaft adjacent to the output gear. A cam-type torque damper having a spring that presses the cam of the cylindrical member and a cam of the cylindrical member against the cam of the output gear and a spring receiving member that receives one end of the spring is formed in a part of the vehicle power unit. It was housed in the gear chamber.
[Selection] Figure 3

Description

  The present invention relates to a vehicle power transmission device including a speed-reducing differential device. The reduction differential is a device that combines a reduction gear and a differential. In the following description, the term “diff” is used to mean “differential device”. This is an abbreviation for “differential”.

  The deceleration differential device is equipped with a torque damper in order to buffer fluctuations in the rotational output of the internal combustion engine. As a prior art, an example in which a torque damper is provided on the output side of a differential device is known (for example, see Patent Document 1). When a torque damper is provided on the output side of the differential device, it is necessary to absorb a torque larger than the torque on the input side of the differential device in order to buffer the torque after deceleration, and it is necessary to enlarge the damper device itself. is there. This also increases weight.

JP 59-167330 A (FIG. 1).

  The problem to be solved by the present invention is to reduce the size of the reduction differential.

  The present invention solves the above-mentioned problem, and the invention according to claim 1 is a differential in which a pinion and a side gear for distributing rotational force to left and right axles are provided in a differential case and a differential input gear is provided on the outer periphery thereof. And an output gear comprising a cam on one end face and rotatably supported by an output shaft, transmitting the rotational force of the internal combustion engine to the differential input gear, and paired with the differential input gear to form a reduction gear, and an end face A cylindrical member that is provided with the other cam and is spline-fitted to the output shaft adjacent to the output gear, a spring that presses the cam of the cylindrical member against the cam of the output gear, and a spring receiving member that receives one end of the spring The present invention relates to a vehicular power transmission device in which a cam type torque damper provided is integrally housed in a final gear chamber formed in a part of a vehicular power unit.

  According to a second aspect of the present invention, in the vehicle power transmission device according to the first aspect, a cam type torque damper is disposed above the differential input gear when the vehicle power unit is mounted on the vehicle. Is.

  According to a third aspect of the present invention, in the vehicle power transmission device according to the first or second aspect, the differential input gear is disposed so as to be displaced in one direction with respect to the pinion shaft that supports the pinion, and the cam type torque damper is provided. Is arranged on the opposite side of the differential input gear with respect to the pinion shaft.

  According to a fourth aspect of the present invention, in the vehicle power transmission device according to the third aspect, the differential case is formed by integrally assembling the left and right case members, and one case member has a wide lateral width, It has a support hole that supports the pinion shaft located at the center in the left-right direction, and a cylindrical portion that is inserted into the bearing at the end and rotatably supports the differential, and the other case member has a narrow lateral width and an outer periphery. And a differential input gear, and a cylindrical portion that is inserted into the bearing at the end portion and rotatably supports the differential device.

  According to the invention of claim 1, since the cam type torque damper is provided on the upstream side of the differential input gear, the cam type torque damper can be reduced in size, and the cam type torque damper is accommodated in the same final gear chamber as the differential input gear. It is possible to improve the mountability to the vehicle body by reducing the size.

  According to the second aspect of the present invention, since the differential input gear is disposed below the cam type torque damper, the lubricity of the differential input gear is improved, and the oil amount can be reduced.

  According to the invention of claim 3, the differential input gear and the cam type torque damper are arranged to be distributed to the left and right with respect to the pinion shaft that is the center of the differential, so that while these are arranged together in the final gear chamber, The differential input gear can be made as large as possible to increase the reduction ratio, and the cam type torque damper can be reduced in size.

  According to the invention of claim 4, the influence of backlash is prevented by integrating the tooth portion with the bearing portion while narrowing the lateral width of the case member having the differential input gear around to improve the workability of the tooth portion. Further, it is possible to reduce the gear meshing noise accompanying the change in the reaction force received from the cam type torque damper and to improve the durability.

  1 is a view of a longitudinal section of a power unit P for mounting a small four-wheeled vehicle to which the present invention is applied as viewed from the right side, and FIG. 2 is a developed sectional view taken along the line II-II of FIG. Arrow A points forward when the vehicle is mounted. The power unit P includes an internal combustion engine E, a gear transmission M, and a reduction differential device F.

  In FIG. 2, the main shells of the power unit are a left crankcase 1, a right crankcase 2, a left crankcase cover 3, a right crankcase cover 4, a left transmission cover 5, a right transmission cover 6, and a cylinder block 7. , A cylinder head 8 and a head cover 9 (FIG. 1).

  A crankshaft 12 is rotatably supported by a left bearing 10 and a right bearing 11 held by the left and right crankcases 1 and 2. A connecting rod 14 and a piston 15 are connected to the crankpin 13 of the crankshaft 12, and the piston 15 is slidably held in the cylinder hole 16 of the cylinder block 7. A combustion chamber 17 is formed in a portion of the cylinder head 8 that faces the piston 15, and a spark plug 18 that penetrates the wall of the cylinder head 8, has a front end facing the combustion chamber 17, and a rear end exposed to the outside. It is provided.

  In FIG. 1, an exhaust port 19 and an intake port 20 are connected to the combustion chamber 17. The exhaust port 19 extends downward, and the intake port 20 extends upward. The exhaust port 19 is provided with an exhaust valve 21, and the intake port 20 is provided with an intake valve 22. A cam shaft 23 is provided in the cylinder head 8. An exhaust rocker arm shaft 24 and an intake rocker arm shaft 25 are provided in parallel with the cam shaft 23. An exhaust rocker arm 26 provided on these arm shafts, an intake air The rocker arm 27 is driven by the cam of the cam shaft 23 to open and close the exhaust valve 21 and the intake valve 22. In FIG. 2, the camshaft 23 is connected to the crankshaft via a camshaft drive chain 30 wound around a camshaft driven sprocket 28 provided at the end thereof and a camshaft drive sprocket 29 provided on the crankshaft 8. Driven by 12. A starter motor 31 (FIG. 1) for initial crankshaft drive is attached to the upper part of the crankcase 1.

  The left crankcase 1 is coupled with a left crankcase cover 3 that covers the opening from the left side, and an alternating current generator 36, in order from the shaft end side, to the left extension of the crankshaft 12 extending inside the left crankcase cover, A starter driven gear 37 for transmitting the rotation of the starter motor 31 to the crankshaft 12 and the camshaft drive sprocket 29 are provided. The right crankcase 2 is coupled with a right crankcase cover 4 that covers the opening portion from the right side. A torque converter 39 and a primary shaft are connected to a right extension portion of the crankshaft 12 that extends into the right crankcase 2 in order from the shaft end side. A reduction gear 40 is provided.

  In FIGS. 1 and 2, a transmission chamber 45 is formed in a space sandwiched between the left crankcase 1, the right crankcase 2, and the right crankcase cover 4. The main shaft 50 is rotatably supported by the left crankcase 1 and the right crankcase 2 via ball bearings 46 and 47, and the counter shaft 51 is rotatably supported by ball bearings 48 and 49. . Although omitted in FIG. 2, the reverse shaft 52 shown in FIG. 1 is also rotatably supported.

  The primary speed reduction device 40 is rotatably supported by the main shaft 50 and a drive gear 41 that is rotatably supported by the crankshaft rightward extension and coupled to the output portion of the torque converter 39. And a driven gear 42 that meshes with the drive gear 41.

  At the right end of the main shaft 50, there is provided a multi-plate clutch 54 that is normally connected but is released when the release mechanism 61 is operated. The multi-plate clutch 54 includes a clutch outer 55 coupled to the driven gear 42 so as to be integrally rotatable, a clutch inner 56 that is spline-fitted to the main shaft 50, and an input side clutch plate 57 that is alternately stacked and frictionally engageable. And an output side clutch plate 58 and a pressure plate 60 that presses the clutch plates 57 and 58 by a clutch spring 59. When the pressure plate 60 is operated by a release mechanism 61 including a clutch arm and a cam mechanism, the pressure plate 60 moves in the axial direction, releases the pressure on both clutch plates, and releases the connection of the multi-plate clutch 54. The rotation of the crankshaft 12 is transmitted to the main shaft 50 via the torque converter 39, the primary reduction gear 40, and the multi-plate clutch 54.

  In FIG. 1, the gear transmission M includes a main shaft 50, a counter shaft 51, a reverse shaft 52, and a shift switching mechanism 53. The shift switching mechanism 53 includes a shift drum 62, a shift fork 63 engaged with the shifter of the main shaft 50, a shift fork 64 engaged with the shifter of the counter shaft 51, and a support shaft 65 common to both the shift forks 63, 64. It has. Shifting gears and shifters that mesh with each other are provided between the main shaft 50, the counter shaft 51, and the reverse shaft 52. The main shaft 50 is provided with gears M1 to M3, MR, and a shifter MS, and the counter shaft 51 is provided with gears C1 to C3, CR, and a shifter CS that mesh with the gears M1 to M3 and MR, respectively. is there. M belongs to the main shaft, C belongs to the counter shaft, subscripts 1 to 3 are for 1st to 3rd gears, subscript R is for backward travel, and subscript S is a shifter. The reverse gears MR and CR are meshed with each other via a reverse dual idle gear (not shown) provided on the reverse shaft 52 (FIG. 1).

The characteristics of these members are as follows.
(X) M1, CR: Gears fixed to the shaft.
(Y) M3, MR, C1, C2: Gears that can rotate with respect to the shaft. Cannot move in the axial direction.
(Z) M2, C3: Gears provided on the shifter and movable in the axial direction together with the shifter. Cannot rotate with respect to the axis. When the shifter is in the neutral position, it meshes normally with the corresponding gear.
(W) MS, CS: Shifters that can move in the axial direction. Cannot rotate with respect to the axis.

  The shifter (W) can occupy a neutral position, an axial rightward movement position, and an axial leftward movement position. When it moves to the right or left in the axial direction, it engages with the adjacent rotatable gear (Y) and fixes the rotatable gear (Y) to the shaft. For this purpose, engagement protrusions that engage with adjacent gears are provided at both ends in the axial direction of the shifter (W), and an engagement recess is provided in the gear that engages with the shifter. Further, a fork engaging annular groove for driving the shifter (W) in the axial direction is provided around the center of the boss portion of the shifter (W).

The shift drum 62 shown in FIG. 1 is rotationally driven by the shift operation of the driver, and depending on the positions of the shifters MS and CS of FIG. As shown in FIG.
(1) First gear shift: When the MS is neutral and CS is moved to the right, the gear is shifted at a gear ratio of M1 and C1.
(2) Second gear shift: When the MS is neutral and CS is moved to the left, the gear is shifted at a gear ratio of M2 and C2.
(3) Third speed change: When MS moves to the right and CS is neutral, the gear is changed at a gear ratio of M3 and C3.
(4) Reverse shift: When the MS moves to the left and is CS neutral, the shift is performed at a gear ratio of MR, reverse dual idle gear, and CR.

  1 and 2, the rear of the transmission chamber 45 is separated from the transmission chamber 45 by left and right crankcases 1 and 2 and a partition wall 68 formed by a part of these crankcases. A gear chamber 69 is provided, in which a reduction differential F is provided. The reduction gear differential F is composed of a reduction gear 79 and a differential device 80. The output shaft 70 is rotatably supported by the left and right crankcases 1 and 2 via ball bearings 77 and 78. The rotational force transmitted from the main shaft 50 to the counter shaft 51 in the gear transmission M is output to the output shaft 70 by the drive gear 66 fixed to the left end of the counter shaft 51 and the driven gear 71 on the left end of the output shaft 70 meshing therewith. Is transmitted to. The rotational force of the output shaft 70 is transmitted from the output gear 73 to the differential input gear 85 of the differential device 80 via the cam type torque damper 72.

  FIG. 3 is a developed sectional view of the deceleration operating device F, and shows a cross section including the counter shaft 51, the output shaft 70, and the rotation center line C of the differential device 80. The output gear 73 is a combination with the adjacent cam type torque damper 72 and cushions it when a variable torque is applied. The output gear 73 is rotatably inserted into the output shaft 70. Adjacent to the right side of the output gear 73, a cylindrical member 74 having an arcuate concave cam 74a (FIG. 5) formed on the end face is spline-fitted to the output shaft 70 and held so as to be movable in the axial direction. A convex cam 73a (FIG. 4) is formed on the end face of the output gear 73 on the cylindrical member 74 side so as to mesh with the concave cam 74a. A spring receiving member 75 is fixed to the right end portion of the output shaft 70, a coil spring 76 is stretched between the cylindrical member 74 and the spring receiving member 75, and the cylindrical member 74 is biased toward the output gear 73. . The cylindrical member 74, the spring receiving member 75, and the coil spring 76 constitute a cam type torque damper 72.

  FIG. 4 is a three-side view of the output gear 73. (A) is a front view, (b) is a BB sectional view of (a), and (c) is a CC sectional view development view of (a). Convex cams 73 a are provided at two positions on the end face of the gear 73.

  FIG. 5 is a three-side view of the cylindrical member 74. (A) is a front view, (b) is a BB sectional view of (a), and (c) is a CC sectional view development view of (a). Concave cams 74 a are provided at two locations on the flange portion on the front side of the cylindrical member 74. This is the portion where the two convex cams 73a of the output gear 73 are engaged. A spline 74b is formed on the inner surface of the central through hole, and engages with the spline 70a on the outer periphery of the output shaft 70.

  The torque of the output shaft 70 is transmitted in the order of the cylindrical member 74, the concave cam 74a of the cylindrical member, the convex cam 73a of the output gear, and the output gear 73. The output gear 73 rotates together with the output shaft 70. When the variable torque is input to the output shaft 70, the concave cam 74a slides in the circumferential direction on the surface of the convex cam 73a, and the cylindrical member 74 moves in the axial direction against the urging force of the coil spring 76. Absorbs and reduces shock. The differential input gear 85 of the differential device 80 is driven by the output gear 73 in which the variable torque is absorbed as described above. The output gear 73, the cam-type torque damper 72, and the differential input gear 85 constitute a speed reduction device 79 for final speed reduction.

  In FIG. 3, the outer shell of the differential device 80 is a differential case 81 formed by connecting a left case member 82 and a right case member 83 with a plurality of connecting bolts 84. The differential input gear 85 is formed on the outer periphery of the left case member 82. Cylindrical portions 82a and 83a formed at the end portions of the left and right case members 82 and 83 of the differential case 81 are inserted into ball bearings 86 and 87 held by the crankcases 1 and 2, respectively, so that the differential case 81 can be rotated. It is supported by. The rotation center line of the differential case 81 is the same as the rotation center line C of the differential device 80 and is parallel to the crankshaft 12, the transmission shafts 50 and 51, and the output shaft 70. The rotation center line C also coincides with the rotation center lines of rear axles 90 and 91 described later.

  Inside the differential case 81, a pinion shaft 88 positioned at the center of the differential device 80 in the left-right direction and orthogonal to the rotation center line C of the differential device 80 is a support hole 83b provided in the wall portion of the right case member 83. An umbrella-shaped pinion 89 is rotatably fitted to both ends of the pinion shaft 88. The inner ends of the left rear axle 90 and the right rear axle 91, which have a rotation center line coinciding with the rotation center line C of the differential case 81 and are supported so as to be independently rotatable on the left and right, are inserted into the differential case, Umbrella-shaped side gears 92 and 93 fixed to the inner end mesh with the pinion 89. The differential device 80 is configured by a combination of the above members, and the rotation input from the differential input gear is appropriately distributed to the left and right rear axles.

The embodiment described above in detail provides the following effects.
(1) Since the cam type torque damper is provided on the upstream side of the differential input gear, the cam type torque damper can be reduced in size, and the cam type torque damper is housed in the same final gear chamber as the differential input gear. Mountability to the vehicle body can be improved.
(2) Since the cam type torque damper is arranged above the differential input gear when the vehicle power unit is mounted on the vehicle, the differential input gear is arranged below the cam type torque damper. The oil quantity can be reduced.
(3) Since the differential input gear is displaced with respect to the pinion shaft supporting the pinion and the cam type torque damper is disposed on the opposite side of the differential input gear with respect to the pinion shaft, the differential input gear and the cam Type torque dampers are arranged to be distributed to the left and right with respect to the pinion shaft located at the center of the differential in the left-right direction, and the differential input gear is enlarged as much as possible to reduce the speed while being arranged in the same final gear chamber The ratio can be increased and the cam type torque damper can be reduced in size.
(4) The differential case is formed by integrally assembling the right and left case members, and the right case member has a wide width and a cylindrical portion that is inserted into the bearing at the end portion and rotatably supports the differential device, The left case member has a narrow width, a differential input gear on the outer periphery, and a cylindrical portion that is inserted into the bearing at the end and rotatably supports the differential, so the left case member has a tooth portion of the differential input gear. Workability is improved, the tooth part is integrated with the bearing part to prevent the effect of backlash, gear meshing noise due to reaction force change received from the cam type torque damper can be reduced, and durability can be improved. .

It is a longitudinal cross-sectional view of the power unit P for small-sized four-wheeled vehicles with which this invention is applied. FIG. 2 is a developed sectional view taken along the line II-II in FIG. 1. FIG. 3 is a cross-sectional development view of a deceleration differential device F. 3 is a three-side view of an output gear 73. FIG. 3 is a three-side view of a cylindrical member 74. FIG.

Explanation of symbols

  P: Power unit, E: Internal combustion engine, F: Reduction differential, C: Differential rotation center line, 68: Bulkhead, 69: Final gear chamber, 70: Output shaft, 72: Cam type torque damper, 73: Output Gears 73a ... Convex cams 74 ... Cylindrical members 74a ... Concave cams 75 ... Spring receiving members 76 ... Coil springs 80 ... Differential gears 81 ... Differential cases 82 82 Left side case members 82a ... Cylindrical parts 83 ... right side case member, 83a ... cylindrical part, 83b ... pinion shaft support hole, 84 ... coupling bolt, 85 ... differential input gear, 86 ... left ball bearing, 87 ... right ball bearing, 88 ... pinion shaft, 89 ... pinion, 90 ... left rear axle, 91 ... right rear axle, 92 ... left side gear, 93 ... right side gear.

Claims (4)

A differential having a pinion and a side gear for distributing rotational force to the left and right axles in a differential case and a differential input gear on its outer periphery;
An output gear that includes one cam on the end face and is rotatably supported by the output shaft, transmits the rotational force of the internal combustion engine to the differential input gear, and forms a reduction gear paired with the differential input gear;
A cylindrical member that is provided with the other cam on the end face and is spline-fitted to the output shaft adjacent to the output gear, a spring that presses the cam of the cylindrical member against the cam of the output gear, and a spring receiving member that receives one end of the spring A cam-type torque damper with
A power transmission device for a vehicle, which is integrally housed in a final gear chamber formed in a part of the vehicle power unit.   2. The vehicle power transmission device according to claim 1, wherein a cam type torque damper is disposed above the differential input gear when the vehicle power unit is mounted on the vehicle. The differential input gear is arranged displaced to one side with respect to the pinion shaft supporting the pinion,
3. The vehicle power transmission device according to claim 1, wherein the cam type torque damper is disposed on the opposite side of the differential input gear with respect to the pinion shaft. The differential case is formed by assembling the left and right case members together,
One case member is wide and has a support hole for supporting a pinion shaft located at the center in the left-right direction of the differential device, and a cylindrical portion that is inserted into a bearing at the end portion and rotatably supports the differential device With
4. The vehicle according to claim 3, wherein the other case member has a narrow width, has a differential input gear on the outer periphery, and has a cylindrical portion inserted into a bearing at an end portion to rotatably support the differential device. Power transmission device.

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