JPH04262149A - Power transmission device - Google Patents

Abstract

PURPOSE:To stably transmit power even in any steering angle with driving and driven parts full rotatably joined. CONSTITUTION:First and second housings 2 and 3 are relatively rotatably joined. First and second bevel gears 10 and 14 are mounted on a first housing 2 input shaft 8 and a second housing 3 output shaft 12 respectively. A first transmission shaft 16 is rotatably provided on the rotation shaft line of the respective housings 2 and 3, and third and fourth bevel gears 19 and 20 are mounted on the first transmission shaft 16. A second tubular transmission shaft 24 is rotatably inserted in the outside of the first transmission shaft 16, and fifth and sixth bevel gears 26 and 27 are mounted on the second transmission shaft 24. First and second one-way clutches 22 and 29 are interposed between the first transmission shaft 16 and the fourth bevel gear 20 and between the second transmission shaft 24 and the sixth bevel gear 27 respectively.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a general-purpose power transmission device, and more specifically, a mechanism in which a driving part and a driven part are rotatably coupled, such as a front wheel drive mechanism of a vehicle with both front and rear wheels. This invention relates to a power transmission device.

0002

BACKGROUND OF THE INVENTION Conventional front and rear wheel drive vehicles are disclosed, for example, in Japanese Patent Application Laid-open No. 157921/1983 and Japanese Patent Application Laid-Open No. 61-1989
A three-wheeled automatic buggy disclosed in Japanese Patent No. 181789 is known. FIG. 5 is a plan view schematically showing the front wheel drive mechanism of these three-wheeled buggies. In the conventional front wheel drive mechanism, rotation of an engine (not shown) is transmitted to the front wheels 54 via a drive chain 51, a power transmission device 52, and a driven chain 53. The power transmission device 52 includes an input shaft 55 connected to a vehicle body (not shown), an output shaft 57 connected to a handle 56, and a constant velocity ball joint 58 rotatably connecting them. The constant-velocity ball joint 58 is configured to be able to transmit power to the front wheels 54 even if the bending angle between the input shaft 55 and the output shaft 57 changes due to the rotation operation. Although the same figure shows the constant velocity ball joint 58 arranged horizontally, the same function can be achieved even if the constant velocity ball joint 58 is arranged vertically and the transmission direction is changed using a bevel gear.

[0003]Also, two-wheel drive (2WD) type motorcycles have been known in the past, and the power transmission system to the front wheels uses a constant-velocity ball joint similar to the three-wheeled buggy. Furthermore, a three-wheeled towing vehicle is known as a front-wheel drive type work vehicle. Conventional three-wheeled towing vehicles have an engine mounted in the front of the vehicle body, and are steered by turning the engine together with the front wheels using a handle.

0004

[Problems to be Solved by the Invention] However, since the conventional power transmission devices 52 of three-wheeled buggies and motorcycles use a constant velocity ball joint 58, the input shaft 55
There is also a problem that the output shaft 57 needs to be arranged on the same axis, which increases its width, which naturally limits the installation location of the power transmission device 52. Moreover, the handle 56
If the torque increases while turning, the constant-velocity ball joint 58 attempts to return the output shaft 57 to the same axis as the input shaft 55, resulting in an inconvenience that the return force of the handle 56 becomes stronger. A more important problem is that the operating angle of the constant-velocity ball joint 58 is limited to a certain value, and therefore, the mechanism in which the driving part and the driven part are connected so as to be fully rotatable requires conventional power transmission. Device 52 could not be applied. Furthermore, with conventional three-wheeled towing vehicles, not only the vibrations of the engine are directly transmitted to the steering wheel, but also the heavy engine must be turned to steer, making the steering wheel difficult to operate.

[0005] Therefore, an object of this invention is to be able to expand the degree of freedom of installation location, to be able to transmit power in a stable state regardless of torque fluctuations, and to connect the driving part and the driven part so that they can rotate at full speed. The object of the present invention is to provide a power transmission device that can also be applied to mechanisms.

[0006]

[Means for Solving the Problems] In order to solve the above problems, the power transmission device of the present invention rotatably couples a first housing and a second housing, and rotatably connects an input shaft to the first housing. a first bevel gear is mounted on the input shaft, an output shaft is rotatably supported on the second housing,
A second bevel gear is attached to the output shaft, a first transmission shaft is rotatably provided on the rotational axis of the first housing and the second housing, and a third bevel gear meshed with the first bevel gear is attached to the first transmission shaft. A gear and a fourth bevel gear meshing with the second bevel gear are installed, a cylindrical second transmission shaft is rotatably inserted outside the first transmission shaft, and the first bevel gear is attached to the second transmission shaft. A fifth bevel gear that meshes with the second bevel gear and a sixth bevel gear that meshes with the second bevel gear are installed, and one-way clutches that act in opposite directions are provided on the first transmission shaft and the second transmission shaft. be done.

The power transmission device of the present invention is a mechanism in which a driving part and a driven part are rotatably coupled, such as a front wheel drive mechanism of a vehicle, a multi-axis drive mechanism of a machine tool, a hand mechanism of a robot, a propulsion mechanism of a ship, Other devices include electric fans and snowmobiles. Preferably, motorcycles, bicycles,
It can be applied to both front and rear wheel drive vehicles such as four-wheeled vehicles, three-wheeled buggies, and forklifts, or front-wheel drive vehicles such as three-wheeled towing vehicles.
A front wheel drive mechanism for a WD bicycle is preferred. In the case of a two-wheeled vehicle, the first housing of the power transmission device is fixed to the vehicle body frame, and the second housing is assembled to the handlebar and front wheel fork. The input shaft of the first housing is connected to the engine via a transmission means such as a chain, a belt, or a spline shaft, and the output shaft of the second housing is connected to the front wheels through a similar transmission means.

[0008]

[Operation] According to the power transmission device of the present invention, the input shaft and the output shaft are disposed on mutually different axes, and their orientation can be adjusted within a 360 degree range by relative rotation of the first and second housings. can be changed arbitrarily. Therefore, the degree of freedom in the installation location of the power transmission device is improved, and the power transmission device can be installed in a compact form that matches the structure of the front wheel drive mechanism of a two-wheeled vehicle or the like. In this installed state, when the input shaft is driven, the power is transmitted to the output shaft via six bevel gears and two transmission shafts. When high torque is applied to the input shaft, each bevel gear and the transmission shaft are also rotated at high speed, but the four bevel gears and the two transmission shafts are on the same axis as the rotation axis of the first and second housings. rotates at a constant speed around the Therefore, the relative rotational force acting on each housing is suppressed to a minute value, and in the case of a two-wheeled vehicle, there is no fear that a return force will act on the handle, improving operability. Furthermore, when rotational force is applied to the second housing due to steering wheel operation, the one-way clutches provided on the first and second transmission shafts allow rotation of the second housing, and the front wheel is rotated by 36°.
Can be oriented at any angle within 0 degrees. Therefore, the front wheels can be coupled to the vehicle body frame for full rotation, and engine rotation can always be stably transmitted to the front wheels at any steering angle, regardless of torque fluctuations.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples embodying the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a power transmission device according to an embodiment of the present invention, FIG. 2 is a schematic diagram illustrating its action during rotation, FIG. 3 is a schematic diagram illustrating its action during steering, and FIG. 2 is a front view of a motorcycle showing an example of application of the power transmission device of FIG. 1. FIG.

As shown in FIG. 1, the power transmission device 1 of this embodiment is provided with a first housing 2 and a second housing 3. A connecting cylinder 4 is fixed to the lower part of the first housing 2, and a connecting cylinder 5 fixed to the upper part of the second housing 3 is inserted inside this connecting cylinder 4. A ball bearing 6 is interposed between each of the connecting tubes 4 and 5, whereby the first housing 2 and the second housing 3 are coupled so as to be relatively rotatable around an axis passing through the center of the power transmission device 1. ing.

An input shaft 8 is attached to the bearing portion 7 of the first housing 2.
is rotatably supported by a ball bearing 9 around an axis perpendicular to the coupling axis, and a first bevel gear 10 is mounted on the inner end thereof. Further, an output shaft 12 is supported by a ball bearing 13 in the bearing portion 11 of the second housing 3 so as to be rotatable around an axis parallel to the input shaft 8, and a second bevel gear 14 is attached to the inner end of the output shaft 12. ing.

A first transmission shaft 16 is provided on the rotation axis of the first housing 2 and the second housing 3. The upper end of the first transmission shaft 16 is rotatably supported by the top wall of the first housing 2 via a ball bearing 17, and the lower end is rotatably supported by the bottom wall of the second housing 3 via a ball bearing 18. The first transmission shaft 16 can rotate relative to both the first housing 2 and the second housing 3. A third bevel gear 19 that meshes with the first bevel gear 10 is attached to the upper end of the first transmission shaft 16 . Further, at the lower end of the first transmission shaft 16, a fourth bevel gear 20 that meshes with the second bevel gear 14 is provided with a ball bearing 21 and a first one-way clutch 22.
It is attached through. The first one-way clutch 22 transmits, for example, only the leftward rotation of the first transmission shaft 16 to the fourth bevel gear 20.

A cylindrical second transmission shaft 24 is inserted through the outside of the intermediate portion of the first transmission shaft 16 . The second transmission shaft 24 is rotatably supported by the connecting tube 5 of the second housing 3 via a ball bearing 25, and is connected to any of the first housing 2, the second housing 3, and the first transmission shaft 16. It is also possible to rotate relative to each other. A fifth bevel gear 26 that meshes with the first bevel gear 10 is attached to the upper end of the second transmission shaft 24 . Further, a sixth bevel gear 27 that meshes with the second bevel gear 14 is attached to the lower end of the second transmission shaft 21 via a ball bearing 28 and a second one-way clutch 29. The second one-way clutch 29 acts in the opposite direction to the first one-way clutch 22 and transmits, for example, rightward rotation of the second transmission shaft 16 to the sixth bevel gear 27.

The power transmission device 1 configured as described above has the following features:
For example, as shown in FIG. 4, it is installed in a front wheel drive mechanism of a 2WD motorcycle. Here, the first housing 2 of the power transmission device 1 is fixed to a vehicle body frame 31, and the second housing 3 is connected to a handle 32 and a front wheel fork 4.
It is assembled into 2. The input shaft 8 of the power transmission device 1 is connected to a drive shaft 37 of an engine 36 via an input sprocket 33, a drive chain 34, and a drive sprocket 35. The output shaft 12 is connected to a front wheel 41 via an output sprocket 38, a driven chain 39, and a driven sprocket 40. Note that the rear wheel 43 is connected to the engine 36 via a chain 44.

Next, the operation of the power transmission device 1 of this embodiment will be explained based on FIGS. 2 and 3. As shown in FIG. 2, when the engine 36 is driven, the input shaft 8 and the first bevel gear 10 are rotated clockwise, the third bevel gear 19 and the first transmission shaft 16 are rotated counterclockwise, and the fifth The bevel gear 26 and the second transmission shaft 24 are rotated clockwise. The first transmission shaft 16 is connected to the fourth bevel gear 20 via a first one-way clutch 22 for left rotation, and the second transmission shaft 24 is connected to the sixth bevel gear 20 via a second one-way clutch 29 for right rotation. It is connected to gear 27. Therefore, the second bevel gear 14 and the output shaft 12 are rotated clockwise by the fourth bevel gear 20 and the sixth bevel gear 27, and the front wheels 41 are driven forward. In this state, when high torque is applied to the input shaft 8 due to acceleration of the engine 36,
Accordingly, each bevel gear 10, 14, 19, 20, 26,
27 and the transmission shafts 16, 24 are also rotated at high speed. However, the third to sixth bevel gears 19, 20, 26, 27 and the first,
The second transmission shafts 16 and 24 are the first and second housings 2 and 3.
Since it rotates at a constant speed around the same axis as the rotation axis of
The rotational force acting on the second housing 3 is suppressed to a minute value. Therefore, unlike a conventional power transmission device using a constant velocity ball joint, there is no risk of a return force acting on the handle 32, and the handle 32 can be operated easily.

On the other hand, as shown in FIG. 3, when the engine 36 is stopped, the handle 32 is turned to rotate the second housing 3, for example, to the left around its axis (hereinafter, the rotation of the housing around its axis is referred to as revolution). Then, as the output shaft 12 and the second bevel gear 14 revolve, the fourth bevel gear 20 and the sixth bevel gear
A leftward rotational force acts on the bevel gear 27. At this time, the sixth bevel gear 27 is connected to the second one-way clutch 29 for clockwise rotation.
Therefore, the second bevel gear 14 is rotated clockwise by the sixth bevel gear 27, and the fourth bevel gear 20 is rotated counterclockwise by the second bevel gear 14. The left rotation of the fourth bevel gear 20 is allowed by the first one-way clutch 22 for left rotation, so the second bevel gear 14 revolves while rotating the fourth bevel gear 20. Thereby, the second housing 3 can revolve to the left, and the handle 32 can be operated in the same direction. Further, when the second housing 3 is revolved to the right, the fourth bevel gear 20 and the sixth bevel gear 27 act in the opposite manner to the above and allow the revolution, so that the handle 32 is rotated in both left and right directions. The front wheel 41 can be operated at any angle within a 360 degree range.

Therefore, even while the engine 36 is rotating, the second housing 3 is allowed to revolve in both directions, and the handle 32 can be operated without any trouble. can be transmitted to the front wheels 41 in a stable manner regardless of torque fluctuations. Moreover, the power transmission device 1 of this embodiment
According to , the input shaft 8 and the output shaft 12 are provided at separate positions and the entire structure is elongated, so that the power transmission device 1 can be arranged between the vehicle body frame 31 and the front wheel fork 42 in a compact form. It can be installed with a good appearance, and
This can also have the function of a frame that supports the front wheels 41. Furthermore, since the orientation of the input shaft 8 and the output shaft 12 can be changed arbitrarily within a range of 360 degrees by relative rotation of the first and second housings 2 and 3, the installation location of the power transmission device 1 can be changed as shown in the example. It is not limited and can be freely selected according to the structure of the front wheel drive mechanism of the motorcycle.

By the way, in the power transmission device 1 of the above embodiment, the first one-way clutch 22 is connected to the first transmission shaft 1.
6 and the fourth bevel gear 20, the first one-way clutch 22 is interposed between the first transmission shaft 16 and the third bevel gear 1
9 or in the middle of the first transmission shaft 16, the same effect as in the above embodiment can be obtained in these cases as well. Similarly, the position of the second one-way clutch 29 is not particularly limited as long as it is on the second transmission shaft 24.

Further, in the power transmission device 1 of the above embodiment, since the one-way clutches 22 and 29 are provided on the transmission shafts 16 and 24, as is clear from FIG.
The power on the second side is not transmitted to the input shaft 8, and the structure is such that engine braking is not applied. By doing so, it is possible to prevent the front wheel 41 from spinning due to engine braking, thereby making it possible to run the motorcycle more safely. however,
There are also vehicles such as four-wheeled vehicles that require engine braking, and in this case, the second bevel gear 14 and the fourth bevel gear 2
0. By mounting different bevel gears on top of each other on the sixth bevel gear 27 and interposing a one-way clutch in the overlapping portion of each bevel gear, an engine braking function can be newly added to the power transmission device 1 of the above embodiment. can do.

[0020] The power transmission device of the present invention is used for the following purposes:
The present invention is not limited to the motorcycles of the above embodiments, but can also be applied to front and rear wheel drive vehicles such as bicycles, four-wheeled vehicles, three-wheeled buggies, forklifts, or front-wheel drive vehicles such as three-wheeled towing vehicles. In addition to vehicles, the present invention can be applied to various devices such as multi-axis drive mechanisms of machine tools, hand mechanisms of robots, propulsion mechanisms of ships, electric fans, and snowmobiles. In addition, the present invention is not limited to the above-mentioned embodiments, and it is also possible to embody it by appropriately changing the shape and structure of each part without departing from the spirit of the present invention.

[0021]

Effects of the Invention As detailed above, according to the present invention, the orientation of the input shaft and the output shaft can be changed arbitrarily to increase the degree of freedom in the installation location, and the rotational force acting on the housing can be reduced. In addition to improving the operability of the steering wheel, etc., the housing can be rotated to allow the driving part and the driven part to be connected for full rotation, and the power can be reliably maintained in a stable state at any steering angle. It has an excellent effect of being able to communicate.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a power transmission device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating the operation of the power transmission device of FIG. 1 during rotation.

3 is a schematic diagram illustrating the operation of the power transmission device of FIG. 1 during steering; FIG.

4 is a front view of a motorcycle showing an example of application of the power transmission device of FIG. 1. FIG.

FIG. 5 is a plan view showing a front wheel drive mechanism equipped with a conventional power transmission device.

[Explanation of symbols]

1 Power transmission device
2 First housing 3 Second housing
8 Input shaft 10 First bevel gear
12 Output shaft 14 Second bevel gear 16 First transmission shaft 19 Third bevel gear
20 Fourth bevel gear 22 First one-way clutch 24 Second transmission shaft 26 Fifth bevel gear 27 Sixth bevel gear 29 Second one-way clutch
31 Body frame

Claims (1)

[Claims] 1. A first housing and a second housing are rotatably coupled, an input shaft is rotatably supported on the first housing, a first bevel gear is attached to the input shaft, and a first bevel gear is attached to the second housing. an output shaft is rotatably supported, a second bevel gear is mounted on the output shaft, a first transmission shaft is rotatably provided on the rotation axis of the first housing and the second housing, and a first transmission shaft is rotatably mounted on the first transmission shaft. A third bevel gear that meshes with the first bevel gear and a fourth bevel gear that meshes with the second bevel gear are installed, a cylindrical second transmission shaft is rotatably inserted outside the first transmission shaft, and the A fifth bevel gear that meshes with the first bevel gear and a sixth bevel gear that meshes with the second bevel gear are mounted on the second transmission shaft, and each other is mounted on the first transmission shaft and the second transmission shaft. A power transmission device characterized by being provided with a one-way clutch that operates in the opposite direction.