JP2718527B2 - Vehicle power plant - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power plant for a vehicle, and more particularly, to an engine, a transmission for shifting the rotation output from the engine, and an output from the transmission. And a power transmission member for transmitting the power to drive wheels, and a continuously variable transmission is used as the transmission.

2. Description of the Related Art For example, as a power device used in a vehicle such as a motorcycle, an engine, a transmission, and a power transmission member interposed between the transmission and drive wheels are housed in a continuous casing. A known type of power unit is a so-called power unit, and in this power unit, a belt drive type continuously variable transmission is often used as the transmission.

The bellow drive type continuously variable transmission generally includes a drive pulley having a centrifugal variable diameter structure that is rotationally driven by a crankshaft of an engine, and a driven pulley having a variable diameter structure disposed near a rear wheel that is a drive wheel. And a V-belt wound between these pulleys, and the rotation of the driven pulley is connected to the automatic centrifugal clutch mechanism disposed coaxially with the driven pulley, and the automatic centrifugal clutch. The power is transmitted to the rear wheels via a plurality of reduction gear groups (reduction mechanisms).

The effective winding radius of the V-belt with respect to the driving pulley and the driven pulley changes due to a change in the rotation speed of the crankshaft and the like, whereby the speed is automatically changed.

In this case, in the engine, the crankshaft is disposed so as to be orthogonal to the longitudinal direction of the vehicle body (extend in the width direction), and the drive belt for transmitting the rotation of the crankshaft to the rear wheels extends along the longitudinal direction of the vehicle body. And extend in parallel.

In a motorcycle, the casing also serves as a rear fork for swingably connecting a drive wheel to a vehicle body.

[Problems to be Solved by the Invention] By the way, in the power unit having the above configuration, the power transmission system such as the drive pulley, the driven pulley, and the V-belt is arranged on one side of the vehicle due to its structure. In addition, since the drive pulley and the driven pulley perform a variable-diameter operation (i.e., shifting operation) by being displaced along the width direction of the vehicle body, a space is provided in the vehicle width direction to allow the displacement. There must be.

Further, a drive mechanism, an automatic centrifugal clutch, and a reduction gear group for performing this displacement must be provided so as to be superimposed on the respective pulleys in the width direction of the vehicle.

Therefore, the overall dimensions including the case are increased in the width direction of the vehicle, and the overall width of the vehicle is increased.

On the other hand, since both pulleys, the drive mechanism for displacing the pulleys, the automatic centrifugal clutch, and the reduction gear group are relatively heavy members, these members are connected to one side of the vehicle as described above. If it is arranged to concentrate on the vehicle, it becomes difficult to adjust the balance in the width direction of the vehicle.

In addition, since a driven pulley and a drive mechanism for performing the displacement operation must be provided also on the drive wheel side, when applied to a motorcycle, the weight of the swing end side of the rear fork increases, This leads to an increase in unsprung load of the suspension that supports the drive wheels.

Therefore, conventionally, it is desired to improve such a problem, and the present invention is to solve such a problem remaining in the related art.

[Means for Solving the Problems] The present invention provides a vehicle power unit capable of effectively solving the above-described problems, and includes an engine and a transmission for shifting the rotation output from the engine. And an axle for mounting and supporting the drive wheels and transmitting the output from the transmission to the drive wheels, and a power transmission member disposed between the transmission and the axle are integrally connected to a crankcase of the engine. An output end of the transmission, wherein the transmission shaft, the engine crankshaft, and the axle are disposed in a casing so as to be substantially parallel to each other along a width direction of the vehicle. And a power transmission member for connecting the axle and the input end of the axle, and a power transmission member connecting the axles to one side of the vehicle, wherein the transmission is provided by a swash plate hydraulic pump and a swash plate hydraulic motor. When Consisting of
The hydrostatic stepless transmission in which the pump and the motor are arranged on the same axis and adjacent to each other in the axial direction, and the input end of the transmission is arranged on the same side as the output end, The output end of the transmission is arranged outside the input end.

[Operation] In the hydrostatic continuously variable transmission, the input and output shafts are arranged concentrically, and the weight is made substantially uniform along the length direction. The weight distribution of the power unit is distributed in the width direction of the vehicle by arranging the power unit substantially in parallel with the crankshaft and the axle of the drive wheels disposed along the same. In addition, since the hydrostatic continuously variable transmission completes the gear shifting operation on its output shaft, it is not necessary to mount the driving wheels on the axle side of the driving wheels for shifting, and the drive wheel swings. A heavy object is concentrated near the center to reduce the unsprung load of the suspension that supports the drive wheels.

Example An example of the first and second aspects of the present invention will be described below with reference to FIGS. 1 to 3.

Reference numeral 1 in FIG. 1 denotes a scooter-type motorcycle as a vehicle to which the embodiment is applied.

The motorcycle 1 includes a vehicle body frame 2 extending from the front to the rear of the vehicle body (from left to right in the figure), a front fork 3 rotatably attached to a front end of the vehicle body frame 2, and a lower end of the front fork 3. A front wheel 4 that is freely supported, a handle 5 that is attached to the upper end of the front fork 3 and steers the front wheel 4, a seat 6 that is attached to an upper portion of a substantially middle portion of the body frame 2, and a substantially center of the body frame 2 And a power unit 7 according to the present embodiment attached to the lower part.

As shown in FIGS. 2 and 3, the power unit 7 includes an engine 8 and a hydrostatic continuously variable transmission 9 (hereinafter simply referred to as a continuously variable transmission) that changes the rotation output from the engine 8. And a drive shaft 10 (a so-called shaft drive is employed in the present embodiment) as a power transmission member that is driven to rotate by the continuously variable transmission 9.
An axle 11 that is rotationally driven by the drive shaft 10. The axle 11 is provided between the continuously variable transmission 9 and the drive shaft 10, and between the drive shaft 10 and the axle 11.
And a pair of bevel gears 12 (12a
b) and 13 (13a and 13b) are interposed, and a rear wheel 14 is integrally attached to the axle 11, so that the rotation of the engine 8 is transmitted from the continuously variable transmission 9 via the drive shaft 10 The power is transmitted to the axle 11 and the rear wheel 14.

The engine 8, the continuously variable transmission 9, and the axle 11 of the rear wheel 14 are disposed so as to extend in the width direction of the vehicle and to be parallel to each other. 10 and a casing C2 which is integrally connected to the crankcase C1 of the engine 8 together with the bevel gear 13, is integrated with the engine 8, and as shown in FIG. Is swingably connected via a link 16 to a bracket 15 protruding from a substantially central lower end of the body frame 2.
Thereby, the power unit 7 is configured in the form of a so-called power unit.

The end on the axle 11 side is connected to the vicinity of the rear end of the vehicle body frame 2 by a cushion unit (not shown), whereby a suspension system for the rear wheel 14 is constituted by the power unit 7 and the cushion unit. I have.

 Next, these details will be described.

As shown in FIG. 3, the engine 8 has a crankshaft rotatably mounted in its crankcase C1.
17 is placed horizontally along the width direction of the vehicle. Therefore, the continuously variable transmission 9 and the axle 11 are also arranged along the width direction of the vehicle.

The crankcase C1 has the crankshaft 17
A cylinder block 18 and a cylinder head 19 are sequentially connected so as to be orthogonal to the cylinder block 18. A piston 21 connected to the crankshaft 17 via a connecting rod 20 is slidably fitted in the cylinder block 18, and a cylinder 21 is provided. head
In 19, a cam chain 22 is
The camshaft 23 is rotatably mounted via a camshaft 23.

The rotation of the camshaft 23 swings a rocker arm 24 swingably mounted on the cylinder head 19 to open and close the intake and exhaust valves 25 and 26.

The continuously variable transmission 9 includes a swash plate type hydraulic pump P of a constant displacement type.
And a variable displacement type swash plate type hydraulic motor M. The swash plate type hydraulic pump P and the swash plate type hydraulic motor M are arranged on the same axis, and the continuously variable transmission 9 is
1 and 2, it is located above the crankshaft 17 as viewed from the side of the vehicle.

The hydraulic pump P has an input cylinder shaft 30 rotatably mounted on a casing C2 via a ball bearing 30b, and a support cylinder 31 bolted to the input cylinder shaft 30 which is relatively rotatable via a ball bearing 32. And an odd number of cylinder holes 34 formed at one end side (lower side in FIG. 3) of the cylinder block 33 at intervals around the axis of rotation and parallel to the axis of rotation. And a plurality of pump plungers 35 which are slidably fitted to the respective pump plungers, and a pump swash plate 36 whose front surface is in contact with the outer ends of the pump plungers 35. Pump swash plate 36 has an angular contact bearing on the back
37 is supported by a holder portion 30a of the input cylinder shaft 30 through, is held in a state of being fixed angle inclined about the imaginary trunnion axis O ₁ to the axis of the cylinder block 33 perpendicular to the axis of the cylinder block 33 You.

The angular contact bearing 37 is an input cylinder shaft.
The pump swash plate 36 is provided with a centering action in cooperation with the swash plate holder portion 30a of the pump 30.

A driven gear 38 is fixed to one end of the input cylinder shaft 30, and is meshed with a drive gear 30 fixed to one end of the crankshaft 17, so that the crankshaft 17
To be driven to rotate.

The pump swash plate 36 is rotated by the rotation of the input cylinder shaft 30 by the crankshaft 17 to reciprocate the pump plunger 35 to repeat the suction and discharge steps.

On the other hand, the hydraulic motor M includes a cylinder block 33 used in common with the hydraulic pump P, and other end faces,
A large number of motor plungers 41 slidably fitted in respective odd-numbered cylinder holes 40 formed at intervals around the rotation axis of the cylinder block 33 and parallel to the rotation axis; A motor swash plate 42 for contacting the outer end surface of the motor swash plate 42, a motor swash plate holder 44 for supporting the back of the motor swash plate 42 via an angular contact bearing 43, and a motor swash plate for supporting the back of the motor swash plate holder 44. And a plate anchor 45.

Also, opposing surfaces of the motor swash plate holder 44 and the motor swash plate anchor 45 abutting each other, it is formed on a spherical surface centered at the intersection of the axis and the trunnion axis O ₂ of the cylinder block 33.

Also in this hydraulic motor M, the angular contact bearing 43 is configured to cooperate with the motor swash plate holder 44 to impart a centering action to the motor swash plate 42.

The motor swash plate anchor 45 is fixed to the rear side wall of the casing C2 together with a cylindrical cylinder holder 46 connected to the front end thereof. The cylinder holder 46 rotatably supports a substantially central portion of the cylinder block 33 through a ball bearing 47.

The motor swash plate 42 is configured to move by the rotation of the motor swash plate holder 46 between an upright position that is substantially perpendicular to the axis of the cylinder block 33 and a maximum inclined position that is inclined at a certain angle. .

In the inclined state, the motor plunger 41 reciprocates with the rotation of the cylinder block 33 to repeat the expansion and contraction strokes.

The tilt angle of the motor swash plate holder 44 is adjusted by a tilt mechanism (not shown) connected to the motor swash plate holder 44. Here, the details of the tilting mechanism are omitted.

Further, in the present embodiment, the plungers 35 and 41 are used.
The structure of the contact portion between the swash plate 36 and
Concave portions are formed at the protruding end portions of the swash plates 35 and 41, and protruding portions are formed at portions of the respective swash plates 36 and 42 facing the plungers 35 and 41. It is configured to be fitted. With such a configuration, the amount of projection of each plunger 35/41 from the cylinder block 33 is suppressed, and the strength of each swash plate 36/42 is ensured to reduce the thickness thereof. This is a procedure for bringing the plates 36 and 42 closer to the cylinder block 33 to reduce the size of the continuously variable transmission 9 in the rotation axis direction.

An output shaft 48 is passed through the center of the cylinder block 33 in a state where relative rotation is restricted, and one end of the output shaft 48 is provided with a ball bearing provided inside the input cylinder shaft 30. Supported by 49, this input cylinder shaft 30
The bevel gear 12a is fixed to a portion located outside the input cylinder shaft 30 relative to the input shaft 30.

On the other hand, the other end of the output shaft 48 extends so as to penetrate the motor swash plate 42, the motor swash plate holder 44, and the motor swash plate anchor 45, and a ball bearing 50 is interposed between the motor swash plate anchor 45 and the motor swash plate anchor 45. Be mounted.

The cylinder block 33 has a pump side cylinder hole.
Between the group 36 and the group of cylinder holes 40 on the motor side, an annular inner oil passage 51 and an outer oil passage 52 concentrically arranged around the output shaft 48, and an annular partition wall between the oil passages 51 and 52 and an outer oil passage. Oil passage
The cylinder holes 34 and 40 radially penetrate the outer peripheral wall of the cylinder 52.
And the same number of first valve holes 53 and second valve holes 54, the communication oil passages connecting the respective valve holes 53 and 54 to the outer oil passage 52, and the adjacent cylinder holes 34 and the first valve holes 53. The pump port a communicating with each other, the adjacent cylinder hole 40 and the second valve hole 54
And a number of motor ports b that communicate with each other.

The inner oil passage 51 is formed as an annular groove in the inner peripheral surface of the cylinder block 33, and its open surface is closed by the outer peripheral surface of the output shaft 48.

In the first valve hole 53, a spool type first distribution valve 55 is provided.
The second valve hole 54 also has a spool-type second distribution valve.
56 are slidably fitted to each other. And the first
A first eccentric ring portion 57 surrounding the outer end of the distribution valve 55 is engaged with a second eccentric ring 58 surrounding the second distribution valve 56 via ball bearings 59 and 60, respectively. Is done.

Said first eccentric ring 57 is integrally supported on the support tube 31, the center of the input cylindrical shaft 30 along the imaginary trunnion axis O ₁ (the output shaft
48 (center of 48). The second eccentric wheel 58 is held by the cylinder holder 46 at a position eccentric from the center of the output shaft 48.

According to the continuously variable transmission 9 having such a configuration, the support cylinder 31
(Rotates integrally with input cylinder shaft 30) and cylinder block
When the relative rotation occurs between the cylinder blocks 33, the first distribution valve 55 causes the first eccentric ring 57 to make the stroke a distance twice the eccentric amount in the first valve hole 53 in the radially inner position and the outer position of the cylinder block 33. Reciprocating between the two positions. Then, in the discharge region of the hydraulic pump P, the first distribution valve 55 is moved on the inward position side, whereby the corresponding pump port a is communicated with the outer oil passage 52 and the inner oil passage 51
The hydraulic oil is pumped from the cylinder hole 34 to the outer oil passage 52 by the pump plunger 35 during the discharge stroke, and in the suction area, the first distribution valve 55 moves to the outer position side. The corresponding pump port a is communicated with the inner oil passage 51 and is not communicated with the outer oil passage 52, and hydraulic oil is sucked from the inner oil passage 51 into the cylinder hole 34 by the pump plunger 35 during the suction stroke.

On the other hand, when the cylinder block 33 rotates, each of the second distribution valves 56 causes the second eccentric ring 58 to make the stroke twice as long as the eccentric amount in the second valve hole 54 in the radially inner position and the outer position of the cylinder block 33. Reciprocating between the two positions. Then, in the expansion region of the hydraulic motor M, the second distribution valve 56 moves on the inner position side to connect the corresponding motor port b to the outer oil passage 52 and to block the inner oil passage 51, and High-pressure hydraulic oil is supplied from 52 to the cylinder hole 40 of the motor plunger 41 during the expansion stroke, and in the contraction region, the second distribution valve 56 moves to the outer position side to move the corresponding motor port b inside. Outer oil passage 52 while communicating with oil passage 51
The hydraulic oil is discharged from the cylinder hole 40 of the motor plunger 41 to the inner oil passage 51 during the contraction stroke.

Then, the pump plunger 35 pumps hydraulic oil from the cylinder hole 34 to the outer oil passage 52 while passing through the discharge region, and from the inner oil passage 51 to the cylinder hole 34 while passing through the suction region.
Hydraulic oil is sucked in. The high-pressure hydraulic oil sent to the outer oil passage 52 is supplied to the cylinder hole 40 of the motor plunger 41 located in the expansion region of the hydraulic motor M, while being supplied from the cylinder hole 40 by the motor plunger 41 located in the contraction region. The hydraulic oil is discharged to the inner oil passage 51.

During this time, the reaction torque that the cylinder block 33 receives from the pump swash plate 36 via the pump plunger 35 in the discharge stroke, and the motor plunger in the expansion stroke
The cylinder block 33 is rotated by the sum of the reaction torque received from the motor swash plate 42 via 41, and the rotation torque is transmitted from the output shaft 48 to the drive shaft 10 via the bevel gears 12a and 12b.

In this case, the speed ratio of the output shaft 48 to the input cylinder shaft 30 is given by the following equation.

Therefore, if the capacity of the hydraulic motor M is changed from zero to a certain value, the gear ratio can be changed from one to a certain required value. Moreover, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 41, by operating the motor swash plate holder 44, the motor swash plate 42 is tilted from the upright position to a certain tilt position, so that the gear ratio is 1
From 0 to a certain value.

According to the power unit 7 having the above-described structure, the continuously variable transmission 9 provided therein is a cylindrical member and has a substantially uniform weight distribution in its length direction. Since the output shaft 48 is disposed so as to be parallel to the crankshaft 17 of the engine 8 and the axle 11 of the rear wheel 14, and these are provided along the width direction of the vehicle, The weight balance in the width direction of the vehicle becomes good, and the balance adjustment becomes easy.

Further, in the continuously variable transmission 9 having the above-described configuration, since the speed change operation has been completed at the bevel gear 12a which is the output end of the continuously variable transmission 9, as described above, the continuously variable transmission 9 Between the rear wheel 14 and the axle 11, only the minimum necessary components for power transmission, the bevel gear 12, the drive shaft 10, and the bevel gear 13, are interposed. Even in this case, the deviation of the weight balance in the width direction of the vehicle with the power unit 7 of the vehicle is suppressed, and the adjustment of the balance becomes easier.

Further, since the engine 8 and the continuously variable transmission 9 which are heavy objects of the power unit 7 are centrally arranged near the center of oscillation of the power unit 7, the weight at the swing end side is reduced, Rear wheel
The unsprung load of the suspension that supports 14 is reduced.

Further, the output end of the crankshaft 17 and the continuously variable transmission 9
Input end and its output end, the input end of the axle 11 of the rear wheel 14, and all the coupling parts of the power transmission system called the drive shaft 10 are arranged on one side of the vehicle. Therefore, the assemblability and maintenance / inspection are simplified.

In addition, since the output end of the continuously variable transmission 9 is arranged outside the input end, the engine 8 provided on the input end side can be made compact by this width.

On the other hand, the continuously variable transmission 9 having the above-described structure includes the two swash plates 36 and 42 as members that can be moved in the axial direction during the gear shifting operation.
However, the amount of displacement in the axial direction due to these inclinations is extremely small, and furthermore, the continuously variable transmission 9 is disposed so as to overlap the crankshaft 17 over substantially the entire length thereof, and Since the necessary space is accommodated within the width of the engine 8, the amount of protrusion from the side of the engine 8 is small, and therefore, there is no possibility that the use of the continuously variable transmission 9 will increase the vehicle width.

In this embodiment, as shown in FIG. 1, the continuously variable transmission 9 is disposed above the engine 8, so that the minimum ground clearance can be easily ensured. Are vertically overlapped, the position of the center of gravity of the power unit 7 is closer to the swing center side.

In the above-described embodiment, the various shapes, dimensions, and arrangements of the constituent members shown are merely examples, and can be variously changed based on the type of vehicle to be applied, design requirements, and the like.

For example, although an example in which the continuously variable transmission 9 is disposed above the engine 8 has been described, instead of this, instead of being substantially below the engine 8 as shown in FIG.
It may be arranged at any position around the cylinder block 17 except for the cylinder block 18.

Therefore, an appropriate layout according to the vehicle type is possible.

Also, as power transmission members provided between the continuously variable transmission 9 and the axle 11, bevel gears 12 and 13 and a drive shaft
10 is shown, but alternatively, as shown in FIGS. 5 and 6, a pair of chain sprockets 61 and 62 and a chain 63 wound around them may be used.

Since the final reduction ratio obtained in this case is smaller than the final reduction ratio obtained by the bevel gear 13 shown in the above-described embodiment, the reduction gear group 64 for the purpose of supplementing this is placed upstream of the axle 11. It is provided on the side.

In this case as well, the same configuration is required in the conventional power unit using the V-pulley, so that the superiority over the conventional structure described in the above embodiment remains unchanged.

Further, in the above embodiment, each plunger 35, 41
The structure of the contact part between the swash plate 36 and 42 and the plunger 35
Although the recess formed in the swash plate 41 and the projections formed in the swash plates 36 and 42 are shown as fitting examples, as shown in FIG.
It is also possible to adopt a structure in which concave portions are formed in 36 and 42, and a protruding portion is formed in the protruding end of each of the plungers 35 and 41 so that both are fitted. This structure may be adopted when there is sufficient space around the continuously variable transmission 9 and the dimension of the continuously variable transmission 9 in the longitudinal direction can be increased.

[Effects of the Invention] As described above, the present invention has the following excellent effects.

The built-in hydrostatic continuously variable transmission is a cylindrical structure,
Because it has a nearly uniform weight distribution along its length,
Because the output shaft of the hydrostatic continuously variable transmission is disposed so as to be parallel to the crankshaft of the engine and the axle of the drive wheels, since these are provided along the width direction of the vehicle. Therefore, the weight balance in the width direction of the vehicle is improved, and the balance can be easily adjusted.

In the hydrostatic continuously variable transmission, since the shifting operation is completed at the output end, the minimum necessary for power transmission is required between the hydrostatic continuously variable transmission and the rear wheel axle. Since only the members are interposed, even when these are concentratedly arranged on one side of the vehicle, the deviation of the weight balance in the width direction of the power unit and thus the vehicle is suppressed, and the above-mentioned balance adjustment is further facilitated from this point as well. It becomes something.

Since the engine, which is a heavy object of the power unit, and the hydrostatic continuously variable transmission are arranged close to each other, a concentrated portion of the weight is formed, for example, a suspension device that supports the rear wheel of the motorcycle. In this case, the location where the weight is concentrated can be brought closer to the center of swing, whereby the unsprung load of the suspension can be reduced.

The output end of the transmission, the input end of the axle, and the power transmission member connecting them are arranged on one side of the vehicle, and the input end of the transmission is also on the same side. As a result, the output end of the crankshaft can be arranged on the same side as a result, and the entire power transmission system can be arranged on one side of the vehicle. Therefore, it is possible to improve the assembling property and the simplicity of maintenance and inspection.

Since the output end of the transmission is disposed outside the input end, the width of the transmission allows the engine provided on the input end to be compact.

By arranging the hydrostatic continuously variable transmission so as to overlap substantially the entire length thereof in parallel with the crankshaft, the width of the vehicle body required for shifting operation of the components of the hydrostatic continuously variable transmission is reduced. Since the displacement trajectory along the direction is contained within the width of the engine, the amount of protrusion from the engine side is small. Therefore, there is no possibility that the use of the hydrostatic continuously variable transmission will increase the vehicle width. Absent.

By arranging the hydrostatic continuously variable transmission so as to be substantially parallel to the engine, the hydrostatic continuously variable transmission is arranged at any position around the crankshaft of the engine except for the cylinder block of the engine. And the degree of freedom in layout can be greatly expanded.

[Brief description of the drawings]

1 to 3 show one embodiment of the present invention. FIG. 1 is a side view of a motorcycle as a vehicle to which one embodiment is applied, and FIG. 2 is a longitudinal section of a main part. Side view, 3rd
FIG. 4 is a cross-sectional view of a main part, FIG. 4 is a vertical sectional side view showing a modification of the present invention, and FIGS. 5 and 6 show another modification of the present invention. FIG. 6 is a side cross-sectional view in which parts are omitted. DESCRIPTION OF SYMBOLS 1 ... Motorcycle (vehicle), 7 ... Power device, 8 ... Engine, 9 ... Hydrostatic continuously variable transmission, 10 ... Drive shaft,
11 axle, 12 bevel gear, 13 bevel gear, 14 rear wheel, 17 crankshaft, P swash plate hydraulic pump, M
... Swash plate type hydraulic motor, 48 ... Output shaft, 61 ... Chain sprocket, 62 ... Chain sprocket, 63 ... Chain, C2
…casing.

Continuation of the front page (72) Inventor Yoshihiro Nakajima 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside the Honda R & D Co., Ltd. (72) Inventor Tsutomu Hayashi 1-4-1 Chuo, Wako-shi, Saitama Pref. Inside the research laboratory (72) Inventor Kiyoshi Katahira 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Technical Research Institute Co., Ltd. (56) References JP-A-61-274167 (JP, A) JP-A-55-152953 (JP) , A) JP-A-62-283089 (JP, A) JP-A-61-175124 (JP, A) JP-A-61-100693 (JP, U)

Claims (1)

(57) [Claims] An engine, a transmission for shifting the rotation output from the engine, an axle for mounting and supporting driving wheels and transmitting output from the transmission to the driving wheels, and a transmission between the transmission and the axle. And a power transmission member disposed in a casing integrally connected to a crankcase of the engine, wherein the shaft of the transmission, the crankshaft of the engine, and the axle are arranged in the width direction of the vehicle. An output end of the transmission and an input end of the axle;
In a vehicle power unit in which a power transmission member connecting these components is disposed on one side of the vehicle, the transmission includes a swash plate type hydraulic pump and a swash plate type hydraulic motor, and the pump and the motor are the same. A hydrostatic continuously variable transmission that is arranged on the axis and adjacent to each other in the axial direction, and the input end of the transmission is arranged on the same side as the output end, and the output end of the transmission Is disposed outside the input end.