JPH0243680B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a constant displacement hydraulic motor used for hydraulically driving two-wheeled vehicles such as bicycles and motorcycles.

(Prior Art) As a conventional transmission device for two-wheeled vehicles, a chain transmission type is mainly used, and as a transmission means, a chain exchange type for a multi-stage sprocket has been put into practical use.

Further, as transmission means other than those mentioned above, there are those disclosed, for example, in Japanese Patent Publication No. 34-1722 and Japanese Patent Application Laid-Open No. 54-93754.

(Problems to be Solved by the Invention) However, the above-mentioned chain changeable transmission cannot perform stepless speed change, and the Although transmissions are theoretically capable of continuously variable speed, they have not yet been put into practical use because of problems such as pulsation, noise, and difficulty in obtaining a sufficient gear ratio.

The present invention has been made in order to solve the above-mentioned problems, and in order to enable a continuously variable transmission for two-wheeled vehicles that has low noise and pulsation and can have a wide range of gear ratios, the present invention has been made to solve the above problems. The object is to provide a positive displacement hydraulic motor.

The ideal transmission system of this type is to be stepless and capable of automatic transmission. Another major objective of the present invention is to provide a continuously variable transmission device capable of automatically changing speeds.

Furthermore, conventional two-wheeled vehicles mainly drive the rear wheels using a chain, making it difficult to drive the front wheels, which are steering wheels. The purpose of this invention is to provide a two-wheeled vehicle transmission device that can easily be driven by front wheels.

(Means for solving the problem) In order to achieve the above-mentioned object, in the present invention,
One gear of the gear-type hydraulic motor is made larger in diameter than the other gear, and a shaft cylinder formed integrally with the gear case is provided in the center of this large-diameter gear, and this shaft cylinder is fitted to the hub shaft of the drive wheel. The output shaft of a large-diameter gear formed in a hollow cylindrical shape is rotatably fitted into the shaft cylinder, and the output shaft is connected to the hub of the drive wheel via a one-way clutch. This constitutes a constant displacement hydraulic motor for driving two-wheeled vehicles.

(Function) In the present invention, since the constant displacement hydraulic motor is configured as described above, if this is installed at the output section of the transmission system of a two-wheeled vehicle and a variable displacement hydraulic pump is installed at the input section, pressure oil can be supplied. Since the transmission can be transmitted through the motor, the sprocket and chain required in conventional two-wheeled vehicles are completely unnecessary.

Furthermore, by connecting the constant displacement hydraulic motor of the present invention to a variable displacement hydraulic pump that can change the discharge volume steplessly, stepless speed change can be easily realized, and noise and pulsation can be reduced. In addition, a wide range of gear ratios can be easily obtained.

Furthermore, in a hydraulically-transmitted two-wheeled vehicle that uses the constant displacement hydraulic motor and variable displacement hydraulic pump of the present invention, fluctuations in the driving force of the vehicle immediately appear as changes in the pressure of the transmission fluid. By controlling the discharge amount of the variable displacement hydraulic pump, automatic gear shifting can be easily realized.

Furthermore, the constant displacement hydraulic motor of the present invention is installed in the front wheel, and the fluid discharged by the constant displacement hydraulic pump is sent through a swivel joint (rotary fluid joint) provided in the handle post, thereby achieving front wheel drive. is also possible.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In the diagram, 1 (see Figure 3) is the front wheel of the bicycle, 2 is the front fork, 3 is the handle, 4 is the head pipe, 5 is the main pipe, 6 is the vertical pipe, 7 (see Figure 5) is the hanger pipe, and 8 is the crank. axis, 9
is the crank arm, 10 is the crank pedal, 11
is the saddle, 12 is the backhawk, 13 is the rear wheel, 1
4 is a rear wheel hub axle.

In this embodiment, a variable displacement hydraulic pump A formed in a disc shape is attached to the input part of the bicycle transmission system around the crankshaft 8, and a constant displacement hydraulic motor B of the present invention is attached to the rear wheel hub shaft 14. A connecting member 1 that is attached to the output part of a bicycle's transmission system through a connecting member 1 and has a discharge side oil passage and a suction side oil passage inside.
5 connects the hydraulic pump A and the hydraulic motor B. Note that this connecting member 15 can also serve as a chain stay. Further, it is convenient to use the inside of the vertical pipe 6 as an oil tank.

FIGS. 4 to 8 show preferred embodiments of the variable displacement hydraulic pump A, the eccentric cam eccentric control device C attached thereto, and the automatic transmission actuating device D cooperating therewith. be.

That is, 16 is a disk-shaped pump case, the outer center hole 17 fits into the boss portion 9a of the crank arm 9 as shown in FIG. 5, and the inner center hole 18 allows rotation of an outer eccentric cam to be described later. It has a suitable diameter. And inside this pump case 16,
A plurality of sets (eight sets in this embodiment) of plunger type suction/exhaust devices are arranged radially around the crankshaft 8, which is the central axis. That is, 19 is the cylinder hole,
20 is a plunger, 21 is a cam follower rotatably supported at the inner end of each plunger 20, 22
is a coil spring that always presses the plunger 20 inward. Reference numeral 23 denotes a suction side oil passage provided in a ring shape on the outer periphery of the pump case 16, and this oil passage 23 communicates with an oil tank 25 provided in the vertical pipe 6 through a pipe 24, as shown in FIG. I've let it happen. Reference numeral 26 denotes a discharge side oil passage arranged in parallel with the suction side oil passage 23 on the outer periphery of the pump case 16, and these oil passages 23 and 26 communicate with each cylinder hole 19 through check valves 27 and 28, respectively. It has been done.
27 is a check valve on the suction side, and 28 is a check valve on the discharge side, each of which is constructed of balls 27a, 28a and coil springs 27b, 28b.
Further, the oil passage 29 shown in FIG. 4 is for returning leaked oil to the suction side oil passage 23.

Reference numeral 30 denotes an inner eccentric cam fixed to the crankshaft 8 with a key 31, and this inner eccentric cam 30 is integrally formed with an inner internal gear 33 via a disc portion 32 located outside the pump case 16. be. 3
Reference numeral 4 denotes an outer eccentric cam that is rotatably fitted to the inner eccentric cam 30, and this outer eccentric cam 34 has a protrusion 35 located between the outer surface of the pump case 16 and the disk portion 32 (see FIG. 6). It is formed integrally with
An outer internal gear wheel 38 is formed integrally with a disc portion 37 having a notched groove 36 which is fitted into the projecting piece 35 in a swingable and slidable manner. It has the same number of teeth and the same pitch diameter as the gear wheel 33, and is fitted concentrically to the inner gear wheel 33 so as to be rotatable.

In the embodiment shown in FIG. 6, the circular end of the protruding piece 35 only makes line contact with the cutout groove 36, so in order to increase this contact area, as shown in FIG.
A sliding piece 39 may be inserted between the protruding piece 35 and the notch groove 36.

Further, 40 is a central gear rotatably fitted to the crankshaft 8, 41 is a fixed gear that meshes with the central gear 40 and the one internal gear 38, and this gear 41 is connected to the hanger pipe 7. It is rotatably supported by a protruding bracket 42. 43 is the center gear 40 and the other internal gear 3
3, and is rotatably supported by the free end of an arm 44 whose base is rotatably fitted to the crankshaft 8. A gear 45 is formed at the base of this arm 44, and a fan gear 46 that meshes with this gear 45 is formed integrally with an eccentric operation lever 47, and the intermediate portion thereof is connected to the shaft 4.
It is fixed to the frame via 7a. These gear devices constitute an eccentric control device C for an eccentric cam.

As shown in FIG. 8, the eccentric operating lever 47 is connected to the tip of a piston rod 50 that is connected to a piston 49 in a hydraulic cylinder 48 that constitutes the automatic transmission actuating device D, and the cylinder 48 is connected to a bicycle frame 51. It is pivoted so that it can swing freely. 52 is a coil spring for returning the piston 49 inserted into the cylinder 48, and the pressure chamber 53 on the opposite side of this spring 52 and the discharge side oil passage 26 of the hydraulic pump A are shown by two-dot chain lines in FIG. As shown in FIG. 5, the empty chamber 55 on the side of the coil spring 52 is communicated with the oil tank 25 by a flexible hose 56 as shown by the two-dot chain line in FIG. 5 to drain the leaked oil. It is arranged to be returned to the oil tank 25.

1 and 2 show an embodiment of a constant displacement hydraulic motor B of the present invention that is fitted onto the rear wheel hub shaft 14 of a bicycle to drive the rear wheel hub 57. This is a gear type hydraulic motor consisting of gears. This gear type hydraulic motor has one gear 5.
8 is made larger in diameter than the other gear 59,
A shaft cylinder 61 formed integrally with the gear case 60 is provided at the center of this large-diameter gear 58, and this shaft cylinder 61 is fitted onto the hub shaft 14 of the driving wheel and fixed with a nut 62. The output shaft 63 of the formed large-diameter gear 58 is rotatably fitted into the former shaft cylinder 61, and this output shaft 63 is connected to the hub 57 of the drive wheel via a one-way clutch 64. 65 is a gear case body that is connected to the gear case 60 by bolts 66, 67 is a pressure side recess provided in the gear case body 65, 68 is an oil passage on the pressure side thereof, 69 is a recess on the oil drain side, and 70 is a return side. It is an oil road.

Further, 71 shown in FIG. 2 is a needle roller inserted between the shaft cylinder 61 and the inner peripheral surface of the gear 58, and 72 is a needle roller inserted into the shaft cylinder 61 and the inner peripheral surface of the gear 58.
1, an annular groove for an oil reservoir carved on the circumferential surface of 1, 73 a seal ring, 74 a ball bearing, 75 a needle roller inserted between the output shaft 63 and the shaft hole of the gear case body 65, and 76 the shaft hole. An annular groove 77 for an oil reservoir carved on the inner circumferential surface of the output shaft 73 is a seal ring fitted to the output shaft 73.

Since leaked oil accumulates in the annular grooves 72 and 76, the oil in the annular groove 72 is transferred to the return side oil passage 70 via oil passages (not shown) provided in the shaft cylinder 61 and gear case 60. The oil in the annular groove 76 is guided to the return side oil passage 70 via an oil passage (not shown) provided in the gear case body 65.

As shown in FIG. 3, the variable displacement hydraulic pump A and constant displacement hydraulic motor B are connected by a connecting member 15 which also serves as a chain stay. As shown in FIG. 1, a discharge side oil passage 78 and a suction side oil passage 79 are formed in this connecting member 15, and the discharge side oil passage 26 of the hydraulic pump A is connected to the discharge side oil passage of the connecting member 15. 78 to the pressure side oil passage 68 of the hydraulic motor B, and the return side oil passage 70 of the hydraulic motor B to the suction side oil passage 23 of the hydraulic pump A via the suction side oil passage 79 of the connecting member 15. Connecting.

Next, the operation of this embodiment configured as described above will be explained. When the pedal 10 of the bicycle shown in FIG. 3 is depressed to rotate the crankshaft 8, the inner eccentric cam 30 fixed to the crankshaft 8 via the key 31 is rotated to the crankshaft 8, as shown in FIGS. 4 and 5. It rotates as one. When the cam 30 rotates, the inner internal gear 33 formed integrally with the cam 30 rotates in the direction of arrow E in FIG. arrow F
Rotate in the direction of. If this gear 43 rotates,
Since the center gear 40 that meshes with this rotates in the direction of arrow G, the fixed gear 41 that meshes with this center gear 40 rotates in the direction of arrow H, and as a result, it meshes with this fixed gear 41. The outer internal gear 38 rotates in the direction of arrow I. In this case, since the rotations of the gears 43 and 41 are exactly the same, the inner internal gear 33 and the outer internal gear 38 rotate integrally.

When the outer internal gear 38 rotates, the disk portion 37 shown in FIG. 6 or 7 rotates in the direction of arrow I, and as a result, the notched groove 36 (in the case of FIG. 7, the sliding piece 39) is rotated. The protrusion 35, which is engaged with (via), also rotates in the direction of arrow I. Since the protruding piece 35 and the outer eccentric cam 34 are integrally formed, the outer eccentric cam 34 and the inner eccentric cam 30 rotate almost integrally. Here, the term "almost integral" means that the projecting piece 35 is approximately 90 mm wide as shown by the imaginary line in FIG.
This is because, when rotated, the disc portion 37 lags in rotation by an angle θ (approximately 6 degrees in this embodiment). However, at rotational phases of 180° and 360°, the rotational angles of the protruding piece 35 and the disc portion 37 completely match, so it is safe to assume that the inner eccentric cam 30 and the outer eccentric cam 34 rotate together. Note that in order to reduce the angle θ mentioned above, the inner eccentric cam 30
What is necessary is to set the amount of eccentricity to the minimum necessary amount.

In addition, in order to change the combined eccentricity of the eccentric cams 30 and 34, the eccentric operation lever 47 shown in FIG.
For example, operate in the direction of arrow J. Then, the sector gear 46 rotates in the direction of arrow K using the shaft 47a as a fulcrum, causing the gear 45 that meshes with it to rotate in the direction of arrow G, and as a result, the arm 44 integrated with gear 45 rotates in the direction of arrow L. make it move. However, in this case, if the crankshaft 8 is stationary, the inner internal gear wheel 33 is also stationary, so the arm 44 is positioned at the arrow L.
When rotated as shown, the rocking gear 43 rotates in the direction of arrow F and revolves in the direction of arrow L. Therefore, the center gear 40 rotates in the direction of arrow G, and as a result, the fixed gear 41 is rotated in the direction of arrow H, and the outer internal gear 38 that meshes with it is rotated by arrow I.
Rotate in the direction of. In this case, since the inner internal gear 33 is stationary as described above, the outer internal gear 38 ends up rotating by a predetermined angle with respect to the inner internal gear 33. In other words, the inner eccentric cam 3
The outer eccentric cam 34 rotates with respect to 0.

4 and 5 show the state in which the combined eccentricity of the cams 30 and 34 is maximum, so if the outer eccentric cam 34 rotates with respect to the inner eccentric cam 30 from this state, the combined eccentricity The degree gradually decreases.

As shown in FIG. 4, the inner eccentric cam 30
If the eccentricity of is l ₁ and the eccentricity of the outer eccentric cam 34 with respect to the inner eccentric cam 30 is l ₂ , then l ₁ = l ₂
If the outer eccentric cam 34 rotates 180 degrees from the maximum resultant eccentricity with respect to the inner eccentric cam 30, the resultant eccentricity becomes zero.

That is, the eccentricity of the composite eccentric cams 30, 34 can be set arbitrarily from the maximum eccentricity shown in FIGS. 4 and 5 to the zero eccentricity state.

Note that although the above description of the eccentric operation has been made with respect to the case where the crankshaft 8 is stationary, this eccentric operation is performed even when the crankshaft 8 is rotating in exactly the same way as in the stationary state described above. be.

As described above, when the inner eccentric cam 30 and the outer eccentric cam 34 rotate almost integrally due to the rotation of the crankshaft 8, the cam follower 2, which is in contact with the outer eccentric cam 34 by the action of the coil spring 22,
1, each plunger 20 connects to each cylinder hole 19 through
It reciprocates inside as shown by arrows M and N in FIG. 4 by the action of a cam. That is, when the plunger 20 moves in the direction of the arrow M, oil enters the cylinder hole 19 from the suction side oil passage 23 via the check valve 27, and when the plunger 20 moves in the direction of the arrow N, the oil enters the cylinder hole 19 through the check valve 27. Pressure oil is pushed out to the discharge side oil passage 26 via 28. When the crankshaft 8 rotates once, each plunger 20 operates for one cycle, so that the oil discharged from each plunger 20 is transferred to the discharge side oil passage 26.
leaks into

This spilled oil is removed from the connecting member 15 shown in FIG.
It enters the pressure side recessed part 67 via the discharge side oil passage 78 and the pressure side oil passage 68 of the hydraulic motor B. Therefore, the large diameter gear 58 rotates in the direction of arrow O in FIG. 1, and the small diameter gear 59 rotates in the direction of arrow P.

Since the rotation of the large diameter gear 58 is transmitted to the rear wheel hub 57 via the one-way clutch 64 in FIG.
This allows the bicycle to travel.

Note that when the gears 58 and 59 rotate as described above, oil flows out into the return side oil passage 70 through the oil drain side recessed part 69, and this spilled oil flows into the suction side oil passage 79 in the connecting member 15. The oil is returned to the suction side oil passage 23 in the hydraulic pump A via.

The oil leaked during the above operation is returned to the suction side oil passage through the oil passage 29, the annular grooves 72 and 76, and the oil passage (not shown) in the case that communicates with them. There is no risk of it being washed away.

Moreover, if the oil tank 25 is provided in the vertical pipe 6 as described above and the oil tank 25 and the suction side oil passage 23 of the hydraulic pump A are communicated,
Even if there is some spilled oil, the oil tank 25
Since it is refilled from within, the device can be used for long periods without needing lubrication.

Moreover, since the hydraulic motor B of this embodiment uses only two seal rings as the shaft sealing device, it is possible to reduce the rotational frictional resistance of the gear 58 and improve the transmission efficiency.

The gear 58 has a large diameter and the gear 59 has a small diameter because the gear 58, which is integrated with the output shaft 63, requires a certain diameter in order to fit onto the hub shaft 14 and transmit power to the hub 57. In addition, there is a design limit to the discharge amount per one rotation of the crankshaft 8 of the hydraulic pump A, so in order to increase the rotation ratio of the drive wheels with respect to the crankshaft 8, it is necessary to use the hydraulic motor B.
The diameter of one gear 59 was made small because the amount of oil discharged per revolution cannot be made too large.

In this way, the entire device can be made smaller, and if the gear 59 has a small diameter, the gear case 60,
65 has a streamlined shape, which has the advantage of improving the external shape of the bicycle.

Also, the ratio between the discharge amount of hydraulic pump A and the amount of oil discharged from hydraulic motor B determines the rotation of the drive wheel relative to the rotation of the crankshaft 8, so this ratio must be set to a ratio suitable for each bicycle. It won't happen. For example, the maximum discharge volume of hydraulic pump A is 45 c.c. per revolution.
and the oil discharge volume of hydraulic motor B is 15 per rotation.
If set to cc, this bicycle can rotate the drive wheel three times with one rotation of the crankshaft when the eccentric cam is at its maximum eccentricity.

Therefore, in this bicycle, if the degree of eccentricity of the cam is adjusted by the eccentric operation of the eccentric cam described above, the discharge amount of the hydraulic pump A can be increased or decreased, and the rotation ratio of the drive wheel to the rotation of the crankshaft can be adjusted. , it is possible to continuously change the speed up to zero within the maximum rotation ratio mentioned above. That is, the rotation speed of the crankshaft:the rotation speed of the driving wheels can be varied steplessly in the range of, for example, 1:3 to theoretically 1:0.

Next, the operation of the automatic transmission actuating device D of this embodiment will be explained. The above-mentioned operation of the eccentric operation lever 47 can of course be carried out by a conventional manual operation.
The hydraulic pressure in the discharge side oil passage 26 of the flexible hose 5
4 on the pressure chamber 53 in the cylinder 48.

To run a bicycle, the crankshaft 8 is rotated by depressing a pedal, and in this case, the oil pressure generated in the discharge side oil passage 26 of the hydraulic pump A increases or decreases in proportion to the magnitude of the rotational torque by the crank arm 9. That is, when the driving resistance force of the bicycle is large, the oil pressure acting on the pressure chamber 53 becomes high, and when the driving resistance force is small, the oil pressure acting on the pressure chamber 53 becomes low.

Therefore, as shown in FIG. 8, when the gear ratio is in the standard (midpoint of the gear ratio)
9 is at the midpoint of the operating range, and the pressure chamber 5 at that time
If the thrust of the piston 49 and the spring reaction force of the coil spring 52 are set to be in balance due to the oil pressure acting on the pressure chamber 3, if the driving force increases from the standard state, the oil pressure in the pressure chamber 53 will decrease. Because the piston 49 and piston rod 50 are higher, the arrow Q
As a result of the movement in the direction, the eccentricity of the composite cam formed by the eccentric cams 30 and 34 becomes smaller as described above. Therefore, as a result of the reduction in the discharge amount of the hydraulic pump A, the rotational magnification of the rear wheel 13 driven via the hydraulic motor B with respect to the crankshaft 8 is automatically reduced. In other words, when the crank pedal 10 becomes heavier, the gear ratio is automatically set to a lower magnification.

Conversely, if the driving force decreases from the standard state described above, that is, if the pedal becomes lighter, the oil pressure in the pressure chamber 53 within the cylinder 48 will decrease, causing the piston 49 and piston rod 50 to move in the direction of arrow R in FIG. As a result, the eccentric cams 30, 34
As the eccentricity of the composite cam increases due to this, the discharge amount of the hydraulic pump A increases. For this purpose, the crankshaft 8 of the rear wheel 13 is driven via the hydraulic motor B.
The rotation magnification will automatically increase. That is, when the crank pedal 10 becomes lighter, the gear ratio automatically becomes higher.

Therefore, according to the present invention, it is possible to easily make the bicycle continuously variable and even automatic.

FIG. 9 shows another embodiment using the constant displacement hydraulic motor B of the present invention, and in the figure, the same reference numerals as those described above indicate equivalent parts.

This is configured as a front-wheel drive bicycle, and a hydraulic motor B is attached to the front wheel 1 side, and a swivel joint (rotatable joint for oil passage) 80 is provided in the head pipe 4, and the crankshaft 8 is centered on the bicycle. The installed hydraulic pump A and the hydraulic motor B are connected via a swivel joint 80 by a discharge side oil passage 81 and a suction side oil passage 82. Note that the oil passages 81 and 82 may be provided in the main pipe 5 and the front fork 2, respectively.

In this way, front wheel drive, which is extremely difficult to achieve with conventional chain drive bicycles, can be easily achieved. This front-wheel-drive bicycle can exert power that cannot be obtained with conventional rear-wheel-drive bicycles as cross-country cycling and mountain cycling, which are becoming popular these days.

(Effects of the Invention) Since the constant displacement hydraulic motor of the present invention is as described above, if it is provided at the output section of the transmission system of a two-wheeled vehicle and a variable displacement hydraulic pump is provided at the input section of the transmission system, Many excellent effects can be obtained, such as the following:

(a) Continuously variable transmission of a two-wheeled vehicle can be easily performed. Moreover, since the transmission is performed using fluid pressure (hydraulic pressure), it is possible to reduce noise and pulsation in the transmission system, thereby providing a two-wheeled vehicle with good riding comfort.

(b) Change the rotational magnification of the drive wheel relative to the crankshaft from the set maximum magnification, for example, 1:3 to 1:
Since the gear can be changed steplessly up to 0, it has the advantage of having a very wide shifting range.

(c) Continuously variable speed is possible, and automatic speed change according to the load can be easily implemented using an extremely simple device as shown in the example, which dramatically improves the performance and maneuverability of the bicycle. can be improved.

(d) Since the sprocket and chain required for the transmission system of conventional bicycles are no longer required, there is no problem of getting clothes caught on the chain as in the past, and the appearance is simple and sleek. .

(e) As mentioned above, front-wheel drive, which was extremely difficult in conventional chain-transmission two-wheeled vehicles, can be easily achieved, and the performance of the two-wheeled vehicle can be greatly improved accordingly.

(f) In particular, in the constant displacement hydraulic motor for driving a two-wheeled vehicle of the present invention, one gear of the gear type hydraulic motor has a larger diameter than the other gear, and the large diameter gear is formed integrally with the gear case at the center. This shaft cylinder is fitted and fixed to the hub shaft of the drive wheel, and the output shaft of a large diameter gear formed in a hollow cylindrical shape is rotatably fitted to the shaft cylinder, and this output Since the shaft is connected to the hub of the drive wheel via a one-way clutch, it is easy to attach the hydraulic motor to the drive wheel of a two-wheeled vehicle, and the entire device can be made smaller, and the front gear has a small diameter. If so, there is an advantage that the external shape of the bicycle is improved because the gear case becomes streamlined.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view showing an embodiment of the constant displacement hydraulic motor of the present invention, Fig. 2 is a sectional view taken along the - line in Fig. 1, and Fig. 3 is a fixed displacement hydraulic motor of the present invention installed. FIG. 4 is a longitudinal sectional front view showing an embodiment of the variable displacement hydraulic pump, FIG. 5 is a longitudinal sectional side view of the bicycle, and FIG. FIG. 7 is a modification of FIG. 6, FIG. 8 is a partial cross-sectional rear view taken along the line - in FIG. 5, and FIG. 9 is another embodiment in which the constant displacement hydraulic motor of the present invention is attached to the front wheel. FIG. 2 is a side view of an example bicycle. 1...Front wheel, 2...Front fork, 3...
Handle, 4...Head pipe, 5...Main pipe, 6...Standing pipe, 7...Hanger pipe, 8
...Crankshaft, 9...Crank arm, 10...
...pedal, 13...rear wheel, 14...rear wheel hub axle,
15... Connection member, 57... Rear wheel hub (drive wheel hub), 58... Large diameter gear, 59... Small diameter gear, 60... Gear case, 61... Shaft cylinder, 63...
... Output shaft, 64 ... One-way clutch, 65 ... Gear case body, A ... Variable displacement hydraulic pump, B
...Constant displacement hydraulic motor, C...Eccentricity control device,
D...Automatic gear shift operating device.

Claims (1)

[Claims] 1. One gear of the gear type hydraulic motor is made larger in diameter than the other gear, and a shaft cylinder is provided in the center of this large diameter gear, which is integrally formed with the gear case.
This shaft cylinder is fitted and fixed to the hub shaft of the drive wheel, and the output shaft of a large diameter gear formed in a hollow cylindrical shape is rotatably fitted to the shaft cylinder, and this output shaft is connected to the hub shaft of the drive wheel. A constant displacement hydraulic motor for driving a two-wheeled vehicle, characterized in that the motor is connected via a one-way clutch.