JPH1068455A - Power unit and drive wheel assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compact a power unit and drive wheel assembly comprising a power unit composed of an internal combustion engine and a continuously variable transmission, and a drive wheel(s) by arranging a cylinder block of the internal combustion engine so as to stand close by one side of the drive wheel. SOLUTION: An input shaft 1 and an output shaft 2 of a hydraulic continuously variable transmission T which are coaxially disposed are engaged with each other through the intermediary of a bearing and the input shaft 1 is coaxially connected to a crankshaft 61 of an internal combustion engine E, while the output shaft 2 is fixed to a hub of a drive wheel W, and a cylinder block 63 of the internal combustion engine E connected contiguously to a casing 52 which accepts and supports the crankshaft 61, the input shaft 1 and the output shaft 2 is disposed so as to stand close by one side of the drive wheel W.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a power unit and a drive wheel applied to a vehicle such as a motorcycle or an automobile, and more particularly to an improvement in which a power unit is provided with a continuously variable transmission.

[0002]

2. Description of the Related Art Conventionally, as an assembly of such a power unit and a drive wheel, for example, as disclosed in Japanese Utility Model Publication No. Hei 17-17990, the assembly extends in a direction perpendicular to the crankshaft to one side of a crankcase of an internal combustion engine. A transmission case is provided, and a belt-type continuously variable transmission and a gear reducer connected to the crankshaft are accommodated in the case. Drive wheels are fixed to the output shaft of the reducer, and the cylinder block of the internal combustion engine is fixed. The thing arrange | positioned in front of the said wheel is known.

[0003]

In the above-described assembly of the power unit and the drive wheels, since the distance between the input and output shafts in the belt-type continuously variable transmission needs to be relatively large, the internal combustion engine is required. Therefore, it is necessary to arrange the cylinder block and the drive wheels in front and rear, which makes it extremely difficult to make the assembly compact.

The present invention has been made in view of such circumstances, and provides a compact power unit and drive wheel assembly in which a cylinder block of an internal combustion engine can be disposed adjacent to one side of a drive wheel. The purpose is to:

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a hydraulic continuously variable transmission in which an input shaft and an output shaft are coaxially arranged, and opposite ends of both shafts are connected via a bearing. The input shaft is coaxially connected to one end of the crankshaft of the internal combustion engine, and the crankshaft and the input and output shafts are housed and supported in a common casing to constitute a power unit. A part of the cylinder is disposed in the rim of the driving wheel, a hub of the driving wheel is mounted on the output shaft, and a cylinder block of the internal combustion engine connected to one side of the casing is disposed adjacent to one side of the driving wheel. Is a first feature.

According to the present invention, in addition to the first feature, a plurality of first plungers radially disposed on a cylinder body fixed to an input shaft, and a hydraulic continuously variable transmission are provided.
A first pump ring which surrounds the plungers and movably engages with the outer ends thereof to reciprocate each first plunger with the rotation of the cylinder body and capable of adjusting the reciprocating stroke thereof; A variable capacity first radial hydraulic pump, a plurality of second plungers radially disposed on a cylinder body, and fixedly mounted on an output shaft and surrounding the second plungers and moving relative to their outer ends; The second plunger engages as much as possible and gives a reciprocating motion of a constant stroke to each second plunger with the relative rotation with the cylinder body.
A high-pressure oil passage, in which a first hydraulic pump sucks hydraulic oil and discharges hydraulic oil from the second hydraulic pump, into the cylinder body, and a radial type second hydraulic pump having a fixed capacity including a pump ring. A second feature is that a low-pressure oil passage for discharging hydraulic oil from the first hydraulic pump and sucking hydraulic oil into the second hydraulic pump is provided.

According to a third feature of the present invention, in addition to the first feature, the crankshaft and the input shaft are integrally connected and the connected portion is supported by a casing via a common bearing. And

Further, according to the present invention, in addition to the first feature, a heat shield plate interposed between the drive wheel and the cylinder block is connected to the fender covering the upper portion of the drive wheel.
The feature of.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on embodiments of the present invention shown in the accompanying drawings.

First, the first embodiment of the present invention will be described with reference to FIGS.
An example will be described. 1 and 2, a power unit U is connected to a drive wheel of a motorcycle, that is, a rear wheel W. The power unit U is supported by a rear end portion of a rear fork 50 pivotally supported by the body frame F so as to be vertically swingable and a lower end portion of a rear cushion unit 51 pivotally supported by the body frame F so as to be able to swing back and forth. .

The power unit U is constituted by connecting an internal combustion engine E and a hydraulic continuously variable transmission T coaxially to each other.
The casing 52 of the power unit U is
c, side cases 52b, 52d located on the left and right sides
And the leftmost side cover 52a are joined to each other to form a substantially cylindrical shape. The left side case 52b and the center case 52c form a crankcase 53 of the internal combustion engine E, and the center case 52c and the right side A transmission case 54 that houses the hydraulic continuously variable transmission T is formed by the case 52d.

The internal combustion engine E includes a crankshaft 61 which is supported by a crankcase 53 via a pair of left and right bearings 55 and 56, and a cylinder block 63 which is connected to the crankcase 53 and accommodates a piston 62. The outer surface of the rotor 65 of the generator 64 fixed to the left end of one end of the crankshaft 61 is covered by a side cover 52a. The input shaft 1 disposed in the transmission case 54 is coaxially spline-fitted to the crankshaft 61 on the side opposite to the generator 64. This input shaft 1
Is supported by the central case 52c via a bearing 57. Referring also to FIG. 3, the right side case 52d
An output shaft 2 penetrating therethrough is supported coaxially with the input shaft 1 via a pair of left and right bearings 58, 59, and a hub Wh of a rear wheel W is provided at an outer end of the output shaft 2. It is detachably spline-fitted and fixed by a nut 69.
The output shaft 2 has a support tube 3 surrounding the distal end of the input shaft 1, and a bearing 60 for supporting the both is provided between the support tube 3 and the input shaft 1. The bearing 58 is provided on the outer periphery of the support cylinder 3.

[0013] Left side case 52b and crankshaft 61
An oil seal 70 is interposed between the bearings 55 and 57, an oil seal 71 is interposed between the central case 52c and the input shaft 1, between the bearings 56 and 57, and an oil seal 71 is interposed between the right side case 52d and the output shaft 2. Are bearings 58 and 59
An oil seal 72 is interposed therebetween.

At least a part of the transmission case 54 is housed in a rim Wr of the rear wheel W,
Is disposed adjacent to one side of the rear wheel W. One end of the fender 73 covering the upper half circumference of the rear wheel W is extended so as to form a heat shield plate 74 interposed between the cylinder block 63 and the rear wheel W.

The hub Wh of the rear wheel W and the right side case 52
A drum type brake 75 is configured between d. That is, the brake 75 is composed of the brake drum 76 integrally formed with the hub Wh and the right side case 52d so as to cover the open surface thereof.
And a flange-shaped brake panel 77 integrally formed with the brake shoe 77. The brake panel 77 includes a brake shoe 7 housed in a brake drum 76 as is well known.
8 and a cam shaft 79 that operates to press the brake shoe 78 against the inner peripheral surface of the brake drum 76 are attached. An operation lever 80 connected to a brake lever (not shown) of the motorcycle via an operation wire is fixed to the cam shaft 79. Therefore, by operating the brake lever, the brake 75 can be operated to apply braking to the rear wheel W.

Now, the configuration of the hydraulic continuously variable transmission T will be described with reference to FIGS. In FIG. 3, the hydraulic continuously variable transmission T is a variable-type first radial hydraulic pump P
_1, constituted by interconnecting a radial second hydraulic pump P ₂ of the constant volume through the closed hydraulic circuit. As shown in FIGS. 3 and 4, the first hydraulic pump P ₁ has a radial arrangement provided on a cylinder body 12 concentrically coupled to the input shaft 1 via a spline 11 so as to open on the outer peripheral surface thereof. (5 in the illustrated example) of the first cylinder holes 13
A first plunger 14 slidably fitted in each of the cylinder holes 13, and a first pump ring 15 surrounding the group of the plungers 14 and slidably engaging with the outer ends thereof in the circumferential direction. And each of the first cylinder holes 13
Accommodates a spring 16 for urging the first plunger 14 in the direction of engagement with the first pump ring 15.

The first pump ring 15 has a boss 15 a formed on one side thereof supported by a transmission case 54 via a pivot 17 parallel to the input shaft 1, and is directed to one side with respect to the cylinder body 12. Distance e ₁ (see FIG. 9A)
It is possible to swing between an eccentric first eccentric position A and a _second predetermined eccentric position C toward the other side with respect to the other eccentric position (see FIG. 12A). Position A, C
A non-eccentric position B (see FIG. 11A) that is concentric with the cylinder body 12 exists between the two. The first and second eccentric positions A and C of the first pump ring 15
The stopper arm 15b projecting from the other side of the transmission case abuts on one of the concave portions 18 formed on the inner peripheral wall of the transmission case 54 and the other inner end wall. And the first
A return spring 19 that constantly biases the pump ring 15 toward the first eccentric position A is interposed between the transmission case 54 and the ring 15, while the return spring 19 resists the biasing force of the return spring 19. Transmission lever 20 that can swing the gear from the first eccentric position A to the second eccentric position C
The shaft 21 is supported. The shift lever 20 is operated by a manual or automatic actuator. Thus, the first pump ring 15 can reciprocate each first plunger 14 according to the amount of eccentricity of the ring 15 when the cylinder body 12 rotates, so that the suction and discharge strokes can be repeated. .

As shown in FIGS. 3 and 5, the second hydraulic pump P ₂ has a plurality of (five in the illustrated example) radially arranged second openings provided on the outer peripheral surface of the cylinder body 12.
A cylinder hole 23, a second plunger 24 slidably fitted in each of the second cylinder holes 23, and circumferentially slidably engaged with outer ends of the second plungers 24 surrounding the group of the second plungers 24. And a spring 26 that urges each second plunger 24 in the direction of engagement with the second pump ring 25 in each second cylinder hole 23.
Is stored.

The second pump ring 25 is integrally connected to the support cylinder 3 of the output shaft 2 and is eccentric to the cylinder body 12 by a predetermined distance e ₃ (see FIG. 9A) to one side. Be placed. Thus, the second pump ring 25
When the cylinder body 12 rotates, each second plunger 24 can be reciprocated to repeat the suction and discharge strokes.

As shown in FIG. 3, the first hydraulic pump P ₁ and the second hydraulic pump P ₂ are arranged at one end and the other end of the cylinder body 12 so as to be separated from each other. 1 and an annular high-pressure oil passage 29 further surrounding the low-pressure oil passage 28. The low-pressure oil passage 28 is defined by an annular groove formed on the outer peripheral surface of the input shaft 1 and the inner peripheral surface of the cylinder body 12, and the high-pressure oil passage 29 is formed on the cylinder body 12.

The cylinder body 12 has the same number of the first cylinder holes 13, the first valve holes 31 radially extending adjacent to the inside of the first cylinder holes 13, and the second cylinder holes 23. A second valve hole 32 extending radially adjacent to the inside of the second cylinder hole group 23 is provided. Each first valve hole 31 penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A first pump port 33 extending laterally from the adjacent first cylinder hole 13 is opened on the inner surface of the valve hole 31. Each second valve hole 32 also penetrates from the outer peripheral surface of the cylinder body 12 through the high-pressure oil passage 29 to reach the low-pressure oil passage 28.
A second pump port 34 extending laterally from the adjacent second cylinder hole 23 opens on the inner surface of the valve hole 32.

As shown in FIGS. 3 and 6, the first valve hole 31
A first switching valve 35 of a spool type is slidably fitted to the first switching valve 35, and a first switching ring 37 surrounding the first switching valve 35 is slidably engaged with the outer end of the first switching valve 35 in the circumferential direction. You. The first switching ring 37 is fixed to the transmission case 54 by bolts 39 at a position eccentric by a predetermined distance e _{4 with} respect to the cylinder body 12 as shown in FIG.

When the cylinder body 12 rotates, each of the first switching valves 35 engages with the first switching ring 37 due to the centrifugal force of the first switching valve 35 and the centrifugal oil pressure of the operating oil in the low-pressure oil passage 28. Kept in state. Therefore, the first switching ring 37
As the cylinder body 12 rotates, each first switching valve 35 is reciprocated between a radially inner position and an outer position of the cylinder body 12 in the radial direction.

At this time, if the first pump ring 15 occupies the first eccentric position A, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke is moved by the first switching valve 35 to the low pressure oil passage. , The second pump port 34 corresponding to the second plunger 24 during the suction stroke.
Is connected to the high-pressure oil passage 29 by the first switching valve 37.

If the first pump ring 15 occupies the second eccentric position C, on the contrary, the first pump port 33 corresponding to the first plunger 14 during the discharge stroke becomes the first switching valve 35. While communicating with the high pressure oil passage 29,
The first pump port 33 corresponding to the first plunger 14 during the suction stroke is connected to the low-pressure oil passage 28 by the first switching valve 35.

As shown in FIGS. 3 and 7, the second valve hole 32
A second switching valve 36, which is also of a spool type, is slidably fitted to the second switching valve 36, and a second switching ring 38 surrounding the second switching valve 36 is slidably engaged with the outer end of the second switching valve 36 in the circumferential direction. Is done. The second switching ring 38 is integrally connected to the first pump ring 25 and is connected to the cylinder body 12.
Are disposed so as to be eccentric with respect to a predetermined distance e ₅ .

When the cylinder body 12 rotates, each of the second switching valves 36 engages with the second switching ring 38 by the centrifugal force of itself and the centrifugal oil pressure of the working oil in the low-pressure oil passage 28. Kept in state. Therefore, the second switching ring 38
Reciprocates each second switching valve 36 between a radially inner position and an outer position of the cylinder body 12 with the relative rotation with respect to the cylinder body 12. By the second switching valve 36, the second pump port 34 corresponding to the second plunger 24 during the suction stroke is connected to the low-pressure oil passage 28, while the second pump port corresponding to the second plunger 24 during the discharge stroke. Reference numeral 34 communicates with the high-pressure oil passage 29.

In the above, the low and high pressure oil passages 28, 29,
The first and second valve holes 31 and 32 and the first and second pump ports 33 and 34 constitute a hydraulic closed circuit connecting the first and second hydraulic pumps P ₁ and P ₂ .

Referring again to FIG. 3, the low-pressure oil passage 28 communicates with the oil reservoir 41 at the bottom of the transmission case 54 through a series of supply oil passages 40 formed on the input shaft 1 and the side wall of the transmission case 54. An oil filter 42 is installed at the inlet of the replenishing oil passage 40, and a dust reservoir 44 communicating with the oil reservoir 41 through the through hole 43 is provided in the bottom wall of the transmission case 54.

3, 4, and 8, the cylinder body 12 is provided with low and high pressure oil passages 28 and 29 and first and second oil passages 28 and 29.
In order to form the second pump ports 33 and 34, the blocks are divided into three blocks 12a, 12b and 12c which are overlapped in the axial direction, and these are connected by a plurality of bolts 47 with the seal rings 45 and 46 interposed therebetween. That is, as clearly shown in FIG. 8, the high-pressure oil passage 29 intersects a pair of annular grooves 29a and 29b formed on both end surfaces of the central block 12b, and the adjacent first and second valve holes 31 and 32. And both annular grooves 29a,
29b, and a plurality of through-holes 29c communicating with each other.
The open surfaces of the annular grooves 29a and 29b
a, 12b, and 12c. The first and second
The pump ports 33, 34 are connected to the blocks 12a, 12b, 1
2c is formed in each opposing surface.

The operation of the first embodiment will be described. Referring to FIG. 2, when the internal combustion engine E is operated, its power is transmitted from the crankshaft 61 to the input shaft 1 and is appropriately shifted by the hydraulic continuously variable transmission T. From the output shaft 2 to the rear wheel W
Output to drive it. That is, the rear wheel W is driven by the output of the power unit U, and the motorcycle can run.

In the power unit U, the input and output shafts 1 and 2 of the crankshaft 61 of the internal combustion engine E and the hydraulic continuously variable transmission T are arranged coaxially, and the rear wheel W Are directly connected, the configuration of the power unit U can be simplified. Also, the crankshaft 61
And a cylindrical casing 52 supporting the input and output shafts 1 and 2
Is accommodated in the rim Wr of the rear wheel W, and the casing 5
Since the cylinder block 63 connected to the rear wheel 2 is arranged on one side of the rear wheel W, the assembly of the power unit U and the rear wheel W can be made compact. Further, one end of the fender 73 covering the upper half circumference of the rear wheel W is connected to the cylinder block 6.
Since the heat shield plate 74 is formed to extend between the rear wheel 3 and the rear wheel W, radiant heat from the internal combustion engine E to the rear wheel W, particularly the tire Wt thereof, can be blocked with a simple structure.
Adhesion of the earth and sand scattered from the rear wheel W to the cylinder block 63 can be prevented.

Next, the operation of the hydraulic continuously variable transmission T will be described with reference to FIGS. In each of the drawings, (a) is a schematic cross-sectional view of the first and second hydraulic pumps, and (b) is a developed schematic view of the first and second hydraulic pumps P ₁ and P ₂ .

<State where the gear ratio is steplessly large (see FIG. 9)> In this state, the first pump ring 15 is moved to the first eccentric position A.
By shifting (see FIG. 4), the first volume of the hydraulic pump P ₁ is controlled equal to that of the second hydraulic pump P _2.

Therefore, when the input shaft 1 is rotated, the cylinder body 12 which rotates integrally therewith causes relative rotation between the first pump ring 15 and the second pump ring 25. At this time, the corresponding first plunger 14 in the discharge stroke as the first in the hydraulic pump P ₁ above 1
The pump port 33 communicates with the low-pressure oil passage 28, and the first pump port 33 corresponding to the first plunger 14 during the suction stroke communicates with the high-pressure oil passage 29.
The hydraulic oil is sucked into the low pressure oil passage 28 and discharged.

On the other hand, in the second hydraulic pump P ₂ , the second pump port 3 corresponding to the second plunger 24 during the suction stroke
4 is connected to the low-pressure oil passage 28, and the second pump port 34 corresponding to the second plunger 24 during the discharge stroke is connected to the high-pressure oil passage 29. The hydraulic oil is discharged to the passage 29.

Further, since the capacity of the two hydraulic pumps P ₁ and P ₂ is equal, the entire amount of hydraulic oil discharged from the first hydraulic pump P ₁ to the low-pressure oil passage 28 during one rotation of the cylinder body 12 is reduced by the _second hydraulic pump P _1. P ₂ and the second hydraulic pump P ₂
There will be the total amount of the hydraulic oil to be discharged to the high pressure oil passage 29 is sucked into the first hydraulic pump P _1. Therefore, the first and second plungers 14 and 24 repeat reciprocating motions, respectively. The first and second plungers 14 and 24 merely slide on the inner peripheral surfaces of the first and second pump rings 15 and 25 and do not generate a rotational torque, so that the output shaft is not generated. 2 keeps the stopped state.

<State where the gear ratio is 2, for example (see FIG. 10)> The first pump ring 15 is positioned at an intermediate position between the first eccentric position A (see FIG. 4) and the non-eccentric position B, that is, a position where the eccentric amount becomes en. shifts to the first displacement of the hydraulic pump P ₁ second
Controlled to half the capacity of the hydraulic pump P _2. In this way, during one rotation of the cylinder body 12, the hydraulic oil amount first hydraulic pump P ₁ is sucked from the high-pressure oil passage 29, the second
Since the hydraulic pump P ₂ is half of the amount of hydraulic oil to discharge the high pressure oil passage 29, the second plunger 24 a reaction force in the discharge stroke when the second hydraulic pump P ₂ is discharged the other half of the hydraulic oil Acts on the second pump ring 25 from the
, The output shaft 2 is rotated. As a result, during one rotation of the input shaft 1, the output shaft 2 makes a half rotation.

<State where the gear ratio is 1 (see FIG. 11)>
The pump ring 15 shifts to the non-eccentric position B (see FIG. 4) controls the first volume of the hydraulic pump P ₁ to zero. In this way, hydraulic fluid second hydraulic pump P ₂ is discharged to the high pressure oil passage 29 is not at all taken into the first hydraulic pump P _1,
To lose the place to go, all the second plungers 24 are in the hydraulic lock state, and the input and output shafts 1 and 2 are integrally connected by the cylinder body 12 and the second pump ring 25. It rotates at the same speed.

<A state where the gear ratio is, for example, 0.66 (FIG. 12)
4) The first pump ring 15 is moved to the second eccentric position C (see FIG. 4).
It shifted reference), and the suction region and the discharge region of the first hydraulic pump P ₁ until the same time be reversed, to set the volume to half the second displacement of the hydraulic pump P _2. In this way, during one rotation of the cylinder body 12, the first pump port with one volume of 2 minutes of the first hydraulic pump P ₁ in the second hydraulic pump P _2, corresponding with the first plunger 14 in the discharge stroke 33 discharging the hydraulic oil to the high pressure oil passage 29 from, since is supplied to the second pump port 34 corresponding to the second plunger 24 that were in the discharge stroke in the second hydraulic pump P ₂ before, the second Plunger 2
4 moves to the expansion stroke, and the second pump ring 25 is accelerated by a half rotation in the rotation direction of the cylinder body 12 by the expansion thrust. As a result, the gear ratio becomes 1: 1.5 = 0.66, and the speed is increased.

As is clear from the above, the gear ratio between the input and output shafts 1 and 2 is infinite by shifting the first pump ring 15 from the first eccentric position A to the second eccentric position C steplessly. The control can be performed steplessly from the (neutral state) to the speed increasing state, so that the vehicle can be started smoothly, and at the time of high speed, overdrive can be performed to reduce fuel consumption.

While the cylinder body 12 is rotating, the oil in the oil reservoir 41 is sucked from the supply oil passage 40 into the low-pressure oil passage 28 by the action of centrifugal force and stored. Therefore, the first and second plungers 14, 24 and the first and second switching valves 35, 3
The leakage amount of the hydraulic oil from the sliding surface of the low pressure oil passage 28
Will be replenished immediately.

The hydraulic continuously variable transmission T is composed of a radial type first and second hydraulic pumps P ₁ and P ₂ on a common cylinder body 12. Compared to a combination of a hydraulic pump and a motor, the axial dimension can be greatly reduced and the size can be reduced. In addition, the support cylinder 3 formed at the inner end of the output shaft 2 is supported by the transmission case 54 via a bearing 58, and the support cylinder 3 is
Since the inner end of the input shaft 1 is supported through the shaft, the inner ends of the two shafts 1 and 2 can be firmly supported by the transmission case 54 within a small axial space, and the supporting rigidity can be increased. The transmission case 54 accommodating the hydraulic continuously variable transmission T can be greatly reduced in size in the axial direction, particularly in the axial direction. Therefore, most of the transmission case 54 is mounted on the rim W of the rear wheel W.
r, the cylinder block 6 of the internal combustion engine E
3 can be arranged close to the rear wheel W, and a compact assembly of the power unit U and the rear wheel W can be obtained.

FIGS. 13 and 14 show a second embodiment of the present invention. In this embodiment, the coaxially arranged crankshaft 61 and the input shaft 1 are integrally connected so as to form one shaft, and the connected portion is connected to the central case 52c via a common bearing 56. Supported by Thereby, the number of parts can be reduced, and the crankshaft 61 and the input shaft 1
Can be shortened, and further the axial dimension of the power unit U can be further shortened.

In the crankcase 53, a timing chain 82 together with a valve operating cam shaft 81 of the internal combustion engine E are provided.
A lubricating oil pump 83 is provided, and a replenishing oil passage 40 of the hydraulic continuously variable transmission T is branched from an oil supply passage 84 extending from the oil pump 83 to a lubricating portion of the internal combustion engine E. The lubricating oil of the internal combustion engine E can be used also as the hydraulic oil of the hydraulic continuously variable transmission T, and the hydraulic oil that is insufficient due to the hydraulic pressure leak in the hydraulic continuously variable transmission T is removed by the oil pump 83.
Can be actively replenished from. Hydraulic continuously variable transmission T
A return hole 85 is formed in the central case 52c for returning the hydraulic oil leaked from the inside into the crankcase 53.

Since other structures are the same as those of the previous embodiment, the same reference numerals are given to the parts corresponding to those of the previous embodiment, and the description thereof will be omitted.

The present invention is not limited to the above embodiment, and various design changes can be made without departing from the scope of the present invention. For example, the power unit U of the present invention can be connected to driving wheels of a motor vehicle.

[0048]

As described above, according to the first aspect of the present invention, the input shaft and the output shaft of the hydraulic continuously variable transmission are arranged coaxially, and the opposite ends of both shafts are connected via the bearing. The input shaft is coaxially connected to one end of the crankshaft of the internal combustion engine, and the crankshaft and the input and output shafts are accommodated and supported in a common casing to constitute a power unit. Since the parts are arranged in the rim of the drive wheel, the hub of the drive wheel is mounted on the output shaft, and the cylinder block of the internal combustion engine connected to one side of the casing is arranged adjacent to one side of the drive wheel. In order to reduce the axial size of the power unit, the cylinder block can be arranged adjacent to one side of the driving wheel, and the assembly of the power unit and the driving wheel can be greatly reduced in size.

According to a second feature of the present invention, the hydraulic continuously variable transmission of the power unit is connected to a variable displacement first hydraulic pump connected to the input shaft via a hydraulic closed circuit. As a result, the power unit is configured with the radial type second hydraulic pump having a fixed displacement for driving the output shaft. Therefore, the axial dimension of the hydraulic continuously variable transmission can be reduced, and the power unit can be made more compact.

Further, according to the third feature of the present invention, the crankshaft and the input shaft are integrally connected and the connected portion is supported by the casing via a common bearing, so that the number of parts can be reduced. As a result, the power unit can be made more compact.

According to a fourth feature of the present invention,
A heat shield intervening between the wheel and the cylinder block is connected to the fender covering the upper part of the drive wheel, so the use of the fender cuts off radiant heat from the internal combustion engine to the drive wheel and scatters from the wheel. Adhesion of earth and sand to the internal combustion engine can be prevented.

[Brief description of the drawings]

FIG. 1 is a side view of an assembly of a power unit and a rear wheel for a motorcycle according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a longitudinal sectional side view of a hydraulic continuously variable transmission in the power unit.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 3;

FIG. 6 is a sectional view taken along the line 6-6 in FIG. 3;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 3;

FIG. 8 is a partially enlarged view of FIG. 3;

FIG. 9 is an explanatory diagram of an operation in an infinite speed ratio state.

FIG. 10 is an operation explanatory view in a state of a gear ratio 2;

FIG. 11 is an explanatory diagram of an operation in a state of a speed ratio of 1;

FIG. 12 is an explanatory diagram of an operation in a state of a gear ratio of 0.66.

FIG. 13 is a side view of a power unit and rear wheel assembly for a motorcycle according to a second embodiment of the present invention.

14 is a sectional view taken along line 14-14 in FIG.

[Explanation of symbols]

1 input shaft 2 output shaft 12 cylinder body 13 first cylinder hole 14 first plunger 15 first pump ring 23 ... Second cylinder hole 24... Second plunger 25... Second pump ring 28... ··· Crankcase 54 ··· Transmission case 56 ··· Bearing 60 ··· Bearing 61 ··· Crankshaft 63 ··· Cylinder block 73 ··· Fender 74 ··· Heat insulation plate E · · · · · internal combustion engine P ₁ · · · · first hydraulic pump P ₂ · · · · second hydraulic pump T T · · · · · hydraulic CVT U · · · · · power units W · .... Rear wheel as drive wheel Wh ... Hub W r ... rim

Claims (4)

[Claims] An input shaft (1) and an output shaft (2) of a hydraulic continuously variable transmission (T) are arranged coaxially, and opposed ends of both shafts are fitted to each other via a bearing (60). The input shaft 1 is coaxially connected to one end of a crankshaft (61) of the internal combustion engine (E), and the crankshaft (61) and the input and output shafts (1, 2) are connected to a common casing (52). The power unit (U) is accommodated in and supported by the
2) is arranged in the rim (Wr) of the drive wheel (W), and the output shaft (2) is provided with a hub (W) of the drive wheel (W).
h), and a cylinder block (63) of the internal combustion engine (E) connected to one side of the casing (52) is arranged adjacent to one side of the drive wheel (W).
Assembly of power unit and drive wheels. 2. The hydraulic continuously variable transmission (T) according to claim 1, wherein the hydraulic continuously variable transmission (T) is released to a cylinder body (12) fixed to the input shaft (1).
A plurality of first plungers (14) arranged radially;
Surround these first plungers (14) and at their outer ends
Engage relatively movably, rotate cylinder body (12)
When reciprocating motion is given to each first plunger (14)
A first pump ring capable of adjusting its reciprocating stroke.
(15) and a variable-capacity radial type first hydraulic pressure port.
Pump (P ₁), And a plurality of second radially arranged cylinder bodies (12).
When fixed to the two plungers (24) and the output shaft (2)
Together surrounding these second plungers (24)
The cylinder body (12) engages with the outer end so as to be relatively movable.
The constant rotation of each second plunger (24) with the relative rotation of
A second pump ring (25) for reciprocating the troke;
Fixed-capacity radial type second hydraulic pump (P_Two)
The first hydraulic pump (P) is provided in the cylinder body (12).₁)
Hydraulic oil is sucked into the second hydraulic pump (P_Two) Or
High-pressure oil passage (29) through which hydraulic oil is discharged from the first hydraulic port
Pump (P₁) And the second hydraulic port
Pump (P_Two) And a low-pressure oil passage (28) into which hydraulic oil is sucked.
Power unit and driving vehicle characterized by having
Wheel assembly. 3. The casing (52) according to claim 1, wherein the crankshaft (61) and the input shaft (1) are integrally connected, and the connecting portion is connected via a common bearing (56). An assembly of a power unit and a driving wheel, wherein the assembly is supported by a power unit. 4. The fender (73) covering an upper part of the drive wheel W, the wheel W
An assembly of a power unit and a drive wheel, wherein a heat shield intervening between the cylinder block (63) is provided in series.