JPH09315376A - Reduction gear for motor car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assemblage with compact constitution and eliminate noise and vibration by providing a pulley, connected to the output of planetary roller reduction mechanism provided at the intermediate part of an output shaft of a motor coaxially with the output shaft, coaxially with the output shaft of the motor. SOLUTION: Planetary roller reduction mechanism 30 screw-fastened to a fixed side casing 21 and fitted to a holding part 31 is arranged coaxially with an output shaft 23. A rubber belt 41 is wound around a first pulley 40 coaxially mounted on the output shaft 28 through two bearings and further through a one-way clutch 39. The first pulley 40 connected to the output of the planetary roller reduction mechanism 30 is thus provided coaxially with the output shaft of a motor 24, there is no vibration and noise generated by the eccentricity of input-output shafts, and strength can be increased by the output shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reduction mechanism for an electric vehicle that travels using an electric motor as a drive source.

[0002]

2. Description of the Related Art Conventionally, as shown in Japanese Patent Laid-Open No. 7-95744 (B62M 23/02), a speed reduction mechanism for an electric vehicle of this type is provided with a planetary roller speed reduction mechanism on the output shaft of the electric motor to reduce the output of the electric motor. There was a way to do it.

However, in the speed reducer having the above-described structure, even if the planetary roller speed reducing mechanism is fitted in the casing of the electric motor, the output shaft of the electric motor may not match the input shaft of the planetary roller speed reducing mechanism, or rubbing may occur. There was a possibility that vibration and noise would occur. In addition, there is a problem that the entire structure of the drive unit becomes large.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks, and it is an object of the present invention to provide a quiet deceleration mechanism for an electric vehicle which has a compact structure, is easy to assemble, is free from noise and vibration. It is an issue.

[0005]

According to the present invention, a planetary roller speed reduction mechanism is provided in the middle of the output shaft of the electric motor coaxially with the output shaft, and a pulley connected to the output of the planetary roller speed reduction mechanism is connected to the output of the electric motor. It is characterized in that it is provided coaxially with the shaft.

A one-way clutch is provided between the planetary roller reduction mechanism and the pulley coaxially with the output shaft of the electric motor.

A holding portion for holding the planetary roller reduction mechanism is provided on an outer ring of the planetary roller reduction mechanism, and the holding portion is fitted to the output shaft.

Further, a bearing is provided at a fitting portion of the holding portion with the output shaft.

Further, the output portion of the planetary roller reduction mechanism and the axle are arranged so as to be displaced from each other.

The driving force from the electric motor is output from the output shaft, is decelerated by the planetary roller reduction mechanism, and is transmitted to the pulley via the one-way clutch. The planetary roller speed reduction mechanism, the one-way clutch, and the pulley are fitted on the output shaft coaxially with the output shaft of the electric motor, and are assembled by inserting them in order. Further, the planetary roller reduction mechanism is held by a holding portion that is fitted coaxially with the output shaft of the electric motor via a bearing. Then, by disposing the output portion of the planetary roller deceleration mechanism and the axle at a position displaced from each other to form a space, other parts such as electronic parts can be built in the space.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to FIGS.

First, the overall structure of the electric bicycle will be described with reference to FIG.

Reference numeral 1 denotes a head pipe 2 provided at a front portion,
The main frame 1 is connected to a seat tube 4 provided below the saddle 3. The main frame 1 is provided with a pedal 5 that can be rotated by human power at a portion connected to the seat tube 4.

Reference numeral 6 is a front wheel which is interlocked with the movement of the handle 7 and whose traveling direction is determined by the operation of the handle 7. The front wheel 6 comprises a spoke 8, a rim 9 and a tire 10.

Reference numeral 11 is a rear wheel which serves as a drive wheel.
The vehicle also includes a tire 12, a rim 13, spokes 14, and a drive unit 15 for driving the rear wheel 11.

Reference numeral 16 denotes a front sprocket that rotates with the rotation of the pedal 5, and the front sprocket 16 has a chain.
17 hangs the rotation of the front sprocket 16 to the drive unit.
After being provided on 15 axles, power is transmitted to the sprocket 50.

A battery 18 serves as a power source for an electric motor 24, which will be described later, and contains a 24-volt NiCd battery.
Further, the battery 18 is removable and can be charged indoors when charging.

Reference numeral 19 is a front basket, and 20 is a stand for supporting the bicycle when the vehicle is stopped.

The drive unit 15 described above is shown in FIGS.
Shows a specific configuration.

Reference numeral 21 denotes a disk-shaped fixed casing fixedly attached to the main frame 1. Reference numeral 22 denotes a rotating casing which is coaxial with the fixed casing 21 and rotates outside the fixed casing 21. The fixed casing 21 and the rotating casing 22 together form a hub. The fixed casing 21 is formed of a light alloy having a thickness of 2 mm.

Reference numeral 23 denotes a U-shaped annular rib provided on the outer periphery of the rotating casing 22. The annular rib 23 is fixed to the rotating casing 22 at a plurality of positions.
A spoke 14 is extended from 23 toward a rim 13 on which the tire 12 is mounted. In addition, the annular rib 23,
It is formed of a steel plate and has a thickness of 2.3 mm. The annular rib 23 is formed as a separate component from the rotary casing 22.The annular rib 23 to which the force from the spokes 14 is required to have a high strength is made of a strong material, and is made of a strong material. 22 is made of a material that is weaker than the annular rib 23 and is made thinner, and the material and the material thickness are changed. With this configuration, the driving unit
15 The overall weight can be reduced, and the cost can be reduced by changing the material.

Reference numeral 24 is an electric motor as a drive source, 25 is a rotor, and 26 is a stator. The electric motor 24 is mounted on the fixed casing 21, and a portion of the electric motor 24 projecting from the rotating casing 22 is covered by an electric motor cover 27, and an output shaft 28 of the electric motor 24 is supported by a bearing 29. ing.

Reference numeral 30 denotes a planetary roller reduction mechanism screwed to the fixed casing 21 and fitted to the holding portion 31. The planetary roller reduction mechanism 30 is arranged around the same axis as the output shaft 28. .

The structure of the planetary roller speed reduction mechanism 30 will be described with reference to FIG.

Reference numeral 32 denotes a fixed ring screwed and fixed to the holding portion 31, four planet rollers 33 are provided on the inner circle of the fixed ring 32, and the outer circumference of the planet roller 33 is outside. It is arranged so as to be in contact with the inner circumference of the fixed wheel 32 and to be in contact with the output shaft 28 of the electric motor 24 inside. An output pin 34 is provided at the center of the planetary roller 33.
A needle bearing 35 is provided between the needle bearing 33 and the needle bearing 35.

The planetary roller speed reduction mechanism 30 is a planetary roller deceleration mechanism in contact with the output shaft 28 of the electric motor 24 when the output shaft 28 rotates in the direction of the arrow.
Since 33 starts rotating around the output pin 34 and is in contact with the fixed ring 32, it starts revolving around the output shaft 28 in the arrow direction. By extracting the rotating output from the output pin 34, the output of the electric motor 24 can be decelerated and extracted.
The planetary roller speed reduction mechanism 30 has the configuration shown in FIG.

Numeral 36 denotes a cylindrical support having a bottom surface pivotally supported by the output pin 34 and penetrating the output shaft 28. The support 36 is provided between the output shaft 28 and a bearing 37 via a bearing 37. Further, a distal end is provided via a bearing 38.

Reference numeral 39 denotes a one-way clutch mounted on the outer periphery of the support 36. The one-way clutch 39 prevents the force from the pedal 5 from being transmitted to the electric motor 24, and the driving force of the electric motor 24 is applied to the rotating side casing. To tell 22.

Reference numeral 40 denotes a first pulley which is mounted on the output shaft 28 via two bearings and further coaxially with the output shaft 28 via the one-way clutch 39. The first pulley 40 is made of rubber. The belt 41 is hung.

Reference numeral 42 denotes a second pulley on which the other end of the belt 41 is hung. The second pulley 42 is fixed to the rotating casing 22 by bolts 43. The second pulley 42 has a hollow inside, and a torque detecting unit 56 described later is provided therein.

Reference numeral 44 denotes a tension pulley for adjusting the tension of the belt 41. The tension pulley 44 has a roller 46 attached to one end of a support 45, and a tension pulley 44 attached to the fixed side casing 21 at the other end. A screw 47 is provided, the support body 45 can swing around the part where the screw 47 is attached, the tension pulley 44 is fixed by tightening the other screw 48, and the belt 41 is pressed,
The tension of the belt 41 can be adjusted.

Reference numeral 49 denotes a control board incorporated in the fixed casing 22. The control board 49 is incorporated in a portion having no pulley. Then, the control board 49 is a constant voltage for inputting a starting voltage to a drive circuit or a microcomputer for PWM controlling the electric motor 24, in addition to the microcomputer for controlling the rotation of the electric motor 24 according to the output result from the torque detection unit 56 described later. It is equipped with a circuit and a torque detection circuit.

Reference numeral 50 denotes a rear sprocket on which the chain 17 is hung. The rear sprocket 50 is provided on an axle 51 via a bearing 52, and a one-way clutch 53 is provided.
It is attached to a rotating plate 57 to be described later.

Reference numeral 54 denotes a rotating cylinder provided on the axle 51 via a bearing 55. The rotating cylinder 54 is
It rotates with the rotation of.

Reference numeral 56 denotes a torque detecting unit attached near the second pulley 42 and the axle 51. The torque detecting unit 56 detects a human-powered driving force transmitted through the chain 17, that is, a human-powered torque. It is provided in.

First, referring to FIG.
An explanation will be given based on. FIG. 5 is a schematic diagram of the torque detection unit 56, and each will be described.

The rotating plate 57 is concentric with the axle shaft 51, and a pressing rod 58 and a conversion rod 59 are integrally formed in two axially opposite positions. The pressing rod 58 is formed in a column shape with a bell-shaped surface, and the elastic body, that is, the spring 60 is pressed by a curved portion of the bell shape. And the rotating plate
57 extends and retracts the spring 60, and the other end of the spring 60 is a second pulley.
The second pulley 42 rotates while pressing the inner wall of 42. The conversion rod 59 is a rectangular body extending in the direction of the axle 28, and is formed obliquely so that the tip portion becomes shorter in the rotation direction.

A spring 60 pressed by the pressing rod 58
Has the other end in contact with a part of the rotating side casing 22, and presses the pressing rod
58, the spring 60 is expanded and contracted to rotate the rotating casing 22. At this time, the rotating plate 57 rotates while slightly distorting the rotating casing 22 in accordance with the expansion and contraction size of the expanded and contracted spring 60. Then, the rotating plate 57 rotates according to the distortion caused by human power. At this time, the conversion rod 59 also rotates by a slight rotation of the rotation plate 57 at the same time, and the angled portion 62 that comes into contact with the inclined portion 61 by the inclined portion 61 formed at the tip of the conversion rod 59.
Is pushed to move in the axle 28 direction. A magnetic member, that is, a ferrite ring 63 is attached to the chevron 62, and the ring 63 moves as the chevron 62 moves. A ring 63 is attached to the tip of this ring 63
A C-ring 64 and a spring 65 are provided for biasing toward the 57 side. Therefore, the ring 63 moves in the direction of the axle 28 by the amount of the distortion of the rotating casing 22 and the rotating plate 35.

Reference numeral 66 is a magnetic detecting member, that is, a coil provided in the fixed casing 21 near the ring 63, and the coil 66 converts an inductance change due to the approach of the ring 63 into an electric signal. It is possible to detect the torque of human power by using this output.

The members shown in FIG. 5 are collectively referred to as the torque detection unit 56. Here, the conversion rod 59, the chevron 62, the ring 63, and the coil 66 are referred to as a detection unit, and the degree of expansion and contraction of the elastic body can be detected by these. Also, conversion rod 5
9. The chevron portion 62 and the angled portion 62 are collectively referred to as a conversion member 67, which converts expansion and contraction of the elastic body 60 in the rotational direction into movement in the axle 28 direction.

In the above structure, the ring 63 is made of ferrite, but the ring may be made of a conductive material such as aluminum. Further, although the elastic body is the spring 60, rubber or the like may be an elastic body, and the detecting unit may be configured using a scale capable of detecting expansion and contraction of the rubber. Further, the elastic body may be used as pressure-sensitive rubber, and the expanding and contracting pressure may be extracted as an electric signal.

Next, a power system diagram having the above configuration will be described with reference to FIG.

First, the human power drive system will be described. The human power given by the pedal 5 is transmitted to the rear sprocket 50 by the chain 17 and rotates the rear wheel 11 via the rotating plate 57 and the spring 60. Next, the electric drive system will be described.The magnitude of expansion and contraction of the spring 60, that is, the rotational movement distance of the rotating plate 57 is converted into movement in the axle 28 direction by the conversion member 67,
The ring 63 moves along with the movement. The movement of the ring 63 is converted into a change in the inductance of the coil 66 and is input to the control board 49 as an electric signal. Control board
49 is built in the fixed side casing 21. Then, the control board 49 inputs a signal from the coil 66, and outputs a drive signal to rotate the electric motor 24 based on the signal. The output of the electric motor 24 is the planetary roller reduction mechanism.
The speed is reduced by 30 and the rear wheel 11 rotates via the first pulley 40.

As described above, the first pulley 40 connected to the output of the planetary roller reduction mechanism 30 is connected to the output shaft 28 of the electric motor 24.
Since the structure is provided coaxially with the shaft, vibration and noise do not occur due to the displacement of the input and output shafts, and the strength can be increased by the output shaft.

Since the one-way clutch 39 is provided between the planetary roller speed reduction mechanism 30 and the first pulley 40 coaxially with the output shaft 28 of the electric motor 24, the structure becomes small.

Further, a holding portion 31 for holding the planetary roller speed reduction mechanism 30 is provided on the outer ring of the planetary roller speed reduction mechanism 30.
Since the output shaft 29 is fitted to the output shaft 29, the displacement of the output shaft 29 can be eliminated.

A bearing 37 is provided at the fitting portion of the holding portion 31 with the output shaft 28.
Since the configuration is provided, the holding portion 31 does not generate vibration or noise.

The output shaft 28 of the planetary roller reduction mechanism 30 and the axle
Since 51 and 51 are arranged in parallel, the electric motor 24 can be easily installed in the hub, and the control board 49, the connector, etc. can be stored in the empty space.

[0049]

According to the structure of claim 1 of the present invention, a planetary roller speed reduction mechanism is provided in the middle of the output shaft of the electric motor coaxially with the output shaft, and the pulley connected to the output of the planetary roller speed reduction mechanism is provided in the electric motor. Since it is provided coaxially with the output shaft, vibration and noise do not occur due to the displacement of the input and output shafts, and the strength can be increased by the output shaft.

According to the present invention, the one-way clutch is provided between the planetary roller speed reduction mechanism and the pulley coaxially with the output shaft of the electric motor. Play.

Further, according to claim 3, the outer ring of the planetary roller reduction mechanism is provided with a holding portion for holding the planetary roller reduction mechanism, and the holding portion is configured to be fitted to the output shaft. There is an effect that the deviation can be eliminated.

According to the fourth aspect, since the bearing is provided in the fitting portion of the holding portion with the output shaft, there is an effect that the holding portion does not generate vibration or noise.

According to the fifth aspect of the invention, since the output portion of the planetary roller reduction mechanism and the axle are arranged so as to be displaced from each other, the electric motor can be easily installed in the hub, and the control board can be installed in the empty space. It is possible to store connectors, connectors and the like.

[Brief description of drawings]

FIG. 1 is a side sectional view of a drive unit that is an embodiment of the present invention.

FIG. 2 is a plan configuration diagram of the drive unit.

FIG. 3 is a plan configuration diagram of the planetary roller reduction mechanism.

FIG. 4 is a power system diagram of the same.

FIG. 5 is a schematic view of the operation of the torque detection unit.

FIG. 6 is an overall configuration diagram of the same.

[Explanation of symbols]

 24 Electric motor 28 Output shaft 30 Planetary roller reduction mechanism 40 Pulley (1st pulley) 39 One-way clutch 31 Holding part 37 Bearing 51 Axle

Claims (5)

[Claims] 1. A planetary roller speed reduction mechanism is provided in the middle of the output shaft of the electric motor coaxially with the output shaft, and a pulley connected to the output of the planetary roller speed reduction mechanism is provided coaxially with the output shaft of the electric motor. And a deceleration mechanism for electric vehicles. 2. The reduction mechanism for an electric vehicle according to claim 1, further comprising a one-way clutch provided between the planetary roller reduction mechanism and the pulley coaxially with an output shaft of the electric motor. 3. The electric vehicle according to claim 1, wherein a holding portion for holding the planetary roller reduction mechanism is provided on an outer ring of the planetary roller reduction mechanism, and the holding portion is fitted to the output shaft. Reduction mechanism. 4. A reduction gear mechanism for an electric vehicle according to claim 3, wherein a bearing is provided at a fitting portion of the holding portion with the output shaft. 5. The speed reduction mechanism for an electric vehicle according to claim 1, wherein the output portion of the planetary roller speed reduction mechanism and the axle are displaced from each other.