JPH08130853A - Direct coupled planetary roller reduction gear - Google Patents

Abstract

PURPOSE: To provide a direct coupled motor planetary roller reduction gear having compactness and excellent durability with less vibration and noise. CONSTITUTION: This reduction gear has a thin motor 31 forming a sun roller 32a at the tip of an output shaft equipped with a mounting flange portion on the outer periphery of a casing, a reduction gear casing 41 fitted to an inner roller or an elastic ring 33 concentric with a motor shaft on the inner periphery of an end surface of a drum portion having an window drilled for inserting an output chain to the drum portion of an outer large-diameter cylindrical shape supporting, through a bearing, an output bearing 32 of the same motor with an inner small-diameter cylindrical portion attached to a flange portion, and a tip of the motor output shaft 32 circumscribing the sun roller. Therefore, the gear comprises a plurality of planetary rollers 34 inscribing elastic rings 33 or inner rollers, planetary roller shaft 35 supporting these planetary rollers 34 in a freely rotatable manner, and a planetary roller carrier 36 which fixes and supports said roller shaft 35 and is supported freely rotatably through a bearing on an inner small-diameter cylindrical portion of the reduction gear casing 41 thereby constituting an output of the reduction gear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mora directly connected planetary roller reducer for auxiliary driving of a bicycle.

[0002]

2. Description of the Related Art An example of the arrangement and function of a conventional transmission motor used as auxiliary power for a bicycle is shown in FIG.
8 (JP-A-58-149277), a first freewheel 2 and a second freewheel 3 are attached to a hub 1 of a rear wheel, and a drive sprocket is attached to the first freewheel 2. The first chain 5 is suspended between the second free wheel 3 and the second gear 7 attached to the output shaft of the drive motor 6, and the second chain 7 is suspended between the second chain 7 and the second gear 7. Suspend the chain 8. Further, a torque detector 9 for detecting the magnitude of the tension applied to the first chain 5 and converting it into an electric quantity (for example, the magnitude of electric resistance or electric capacity) is provided in the middle of the first chain 5. For details, refer to FIG. 7 and FIG.
As shown in, a tension arm 11 is attached to the rotating shaft 10 of the torque detector 9, and the free gear 12 and
12 'is pivotally mounted, the first chain 5 is mounted on these two free gears, and the tension arm 11 is provided with a spring 13 for urging rotational force in the clockwise direction in the drawing of FIG.
Install. With this configuration, the tension applied to the first chain 5 due to the stepping force transmitted by the occupant through the pedal 14, the crank 15, and the first gear 4 causes the rotation shaft 10 to rotate. It can be detected as an angle. When the pedal 14 is strongly depressed when starting, accelerating, or climbing a plate, a large tension is applied to the first chain 5, and the tension arm 11 rotates counterclockwise in the drawing against the elastic force of the spring 13. It moves to rotate a slider (not shown) of the potentiometer 9 connected to the rotating shaft 10 by an angle corresponding to the tension. When the motor 6 is rotated more than the required angle, the electric power of the motor 6 is supplied, the second gear 7 attached to the output shaft of the motor 6 is rotated, and the second freewheel 3 is rotated via the second chain 8, The wheels are driven, and therefore the rear wheels are driven by the combined torque of both the human power and the motor. To put it the other way around, the same driving torque is applied to the rear wheels, but the burden of human power is reduced as compared with the conventional bicycle. On the other hand, since a light torque is sufficient for traveling on a flat road, the tension applied to the first chain 5 is also small, and the rotation angle of the tension arm 11 is also small, so the power supply to the motor 6 is stopped and only the rotation of the pedal The power of the bicycle will drive the bicycle.

A general conventional example of the structure of the motor 6, which is the prime mover used for such auxiliary power, will be described. The structure shown in FIG. 9 is a small and compact example. Can be mentioned. That is, the thin DC motor 21 is directly connected to the thin planetary gear reducer.
Reference numeral 22 denotes an output shaft of the motor 21, and the sun gear 22a is directly processed at the tip of the output shaft 22. Internal gear 23 and internal gear 2 mounted on the reducer casing 28
3, a plurality of planetary gears 24 that mesh inwardly with the sun gear 22a, and a planetary gear carrier 26a that supports the planetary gears 24 by respective planetary gear shafts 25 constitute a planetary gear reduction mechanism. . Planet gear carrier 26a
Is integrated with the output shaft 26, a sprocket wheel 27 is attached to the output shaft 26, and a chain for driving the rear wheels of the bicycle is hung on the sprocket wheel 27.

[0004]

As described above, since the speed reducer of the conventional auxiliary power motor is a gear system, there is backlash between the meshing gears, and when used as auxiliary power for a bicycle, speed fluctuations occur when the motor power is applied. Caused vibration and noise, which deteriorated the riding comfort. In addition, since the chain is wrapped around the output end of the power plant, the width of the power device is larger than the width of the bicycle, and the output shaft 26 is easily bent by the cantilever support, making it difficult to balance left and right. there were. For this reason, the present invention solves the above-mentioned conventional problems, and provides a motor-directly connected planetary roller reducer which is compact in vibration and noise, excellent in durability, and excellent in durability.

[0005]

Therefore, according to the present invention, a thin motor having a mounting flange portion on the outer periphery of the casing and a sun roller formed at the tip of the output shaft, and a small inner diameter mounted on the flange portion of the motor. The output shaft of the motor is supported by the cylindrical part through a bearing, and a window for inserting an output chain is formed in the outer cylindrical part of the large diameter, and the inner part of the end face of the same part is elastically concentric with the motor shaft. A reduction gear casing in which a ring or an inner roller is fitted, a plurality of planet rollers that are circumscribing the sun roller at the tip of the motor output shaft and are inscribed in the elastic ring or the inner roller, and a planet roller shaft that rotatably supports these planet rollers. And a planetary roller carrier that fixes and supports the roller shaft and is rotatably supported via a bearing on a small-diameter cylindrical portion inside the reduction gear casing to configure the output of the reduction gear. A planetary roller deceleration mechanism configured and an output sprocket wheel mounted on the planetary roller carrier, and a bearing for supporting the planetary roller carrier is provided inside the output sprocket wheel arranged between the sun roller and the motor. The bearing is arranged so that the tensile force of the chain applied to the output sprocket is directly received, and this serves as means for solving the problem. The present invention also provides a bicycle equipped with an auxiliary power mechanism, wherein the output sprocket of the planetary roller reducer directly connected to the motor is connected to a driven sprocket attached to a rear wheel shaft via a chain.

[0006]

With the above means, the rotation of the output shaft of the motor is reduced to the expected output rotation by the high reduction ratio planetary roller reduction mechanism directly connected to this, and the required torque is output. Since it is a rolling friction drive using a planetary roller, there is little vibration and noise. Since the sun roller is formed at the output shaft end of the thin motor and the planetary roller speed reduction mechanism is formed on the rotation surface of the sun roller, the axial length of the entire combination of the motor and the speed reduction mechanism is shortened. In addition, a reduction mechanism output shaft formed as a planetary roller carrier is provided in the middle of the motor and the reduction mechanism, and an output chain hung on a sprocket wheel attached to the output shaft is the reduction gear casing. Since it is linked to the driven side sprocket wheel through the side window, it is possible to approach the center line of the vehicle body when mounting the reduction gear with motor to a narrow vehicle such as a bicycle, so the device fits It is good and avoids a large weight imbalance. Further, since the bearing for supporting the planetary roller carrier is arranged so as to overlap with the same position inside the output sprocket wheel, the bearing directly receives the tensile force of the chain applied to the output sprocket and has a conventional cantilever structure. Excellent durability because it does not receive bending stress like the output shaft.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described below. FIG. 1 is a side sectional view of a planetary roller reducer 30 directly connected to a motor, and FIG. The structure of the planetary roller speed reducer 30 directly connected to the motor will be described. 31 is a thin disk-shaped armature wired by a print coil,
It is a thin DC motor composed of a permanent magnet stator, a commutation brush, and the like. A sun roller 32a is formed at the tip of the output shaft 32 of the motor 31. A mounting flange is provided on the outer periphery of the motor 31, and the reduction gear casing 41 is mounted on the flange. A small-diameter cylindrical portion 41b provided inside the speed reducer casing 41 supports the motor output shaft 32 via a bearing 50, and a large-diameter cylindrical body portion on the outer side has a pair of large windows 41 symmetrically in a radial direction.
a (FIG. 2) is bored, and a circumferential step portion into which the elastic ring 33 or the shrink fit inner roller 33a is fitted is provided on the inner periphery of the surface of the body portion. A sun roller 32a at the tip of the motor output shaft 32, an elastic link 33 that is fastened and fixed by a speed reducer casing 41 and a speed reducer lid 42,
A plurality of planet rollers 34 that are pressed against this, and a planet roller shaft 35 that rotatably supports the planet rollers 34 via bearings.
And a planetary roller carrier 36 that fixes and supports the roller shaft 35 to form a planetary roller reduction mechanism.
The planetary roller carrier 36 is rotatably supported by a small diameter cylindrical portion 41b inside the reduction gear casing 41 via a bearing 38, and serves as an output shaft of the reduction gear. An output sprocket wheel 37 is attached to the planetary roller carrier 36. Reduction ratio 1 / n of this planetary roller reduction mechanism
Is

## EQU1 ## 1 / n = the diameter of the sun roller / (the diameter of the sun roller / the inner diameter of the elastic ring), and the output torque of the output sprocket wheel 37 is equal to the motor output torque if the mechanical loss of power transmission is ignored. n times. This motor directly connected planetary roller reducer 3
The action of 0 will be described. When the rotation of the output shaft 32 of the motor is reduced to 1 / n as described above by the planetary roller reduction mechanism directly connected to this, a large required torque is obtained, and vibration and noise are small. Output shaft 3 of DC thin motor 31
The sun roller 32a is formed at the two ends, and the sun roller 3a
Since the planetary roller reduction mechanism is formed on the rotation surface of 2a, the axial length of the entire combination of the motor 31 and the reduction mechanism is compact. In addition, the output shaft portion of the planetary roller carrier 36, which serves as a reduction mechanism output shaft to which the output sprocket wheel 37 is attached, is provided between the motor 31 and the reduction mechanism, and the output chain 39 hung on the output sprocket heel 37. However, since it is linked to the driven side sprocket wheel through the window 41a on the side surface of the speed reducer casing 41, it is possible to approach the center line of the vehicle body when it is mounted on a vehicle having a narrow width and light weight such as a bicycle. Therefore, the device fits well and a large weight imbalance can be avoided. Further, a bearing 38 such as a ball bearing that supports the planet carrier 36 is concentrically arranged inside the output sprocket wheel 37 in the radial direction, so that the bearing 38 linearly applies the tensile force of the chain 39 applied to the output sprocket 37. Since it can be received, bending stress unlike the conventional cantilevered output shaft is not received, so that durability is improved and there is no phenomenon such as runout.

Next, an example in which the motor-directly connected planetary roller reducer 30 is attached to a bicycle will be described. FIG. 3 is a side view of the bicycle, and FIG. 4 is an enlarged view of a BB section of FIG.
16 is a bicycle with auxiliary power, 4 is a human-operated crankshaft 1
It is a sprocket wheel attached to No. 5. 1
Reference numeral 4 is a pedal for rotating the crankshaft 15. Further, 5 is a chain that transmits the torque of the crankshaft 15 that is rotated by human power by connecting the driven sprocket wheel 2 and the sprocket wheel 4, which are attached to the shaft of the rear wheel 17 of the bicycle 16 via a one-way clutch. Is. The display of the bicycle part number up to this point is the same as that of the bicycle power mechanism of the conventional example because it has the same structural function. The rim that supports the tire of the rear wheel 17 is a molded product integrated with the rear wheel hub, and the supporting disc portion is biased. With such a structure, the motor-coupled planetary roller reducer 30 can be conveniently mounted between the components of the bicycle 16 as shown in the figure (a large number of spokes normally supporting the rim of a tire). If it is, the motor direct-coupled reducer 30 can be moved to the extent that it does not touch the spokes, but it moves a little lower than that shown in FIG. 4, and in this case, the output sprocket wheel 37 moves outward. Due to the shift, the position of the driven sprocket wheel 45 also moves outward, the hub of the rear wheel becomes slightly longer, and the mounting width of the rear wheel shaft becomes slightly wider.) The output sprocket wheel 37 of the reduction gear and the one-way for the rear wheel shaft of the bicycle The driven sprocket wheel 45 mounted via the clutch is linked by a chain 39. A torque sensor 19 is provided on the pulling side of the chain 5. In this torque sensor 19, a roller at the tip of the lever always pushes up the chain 5 by a spring or the like, and when the chain 5 is strongly pulled, the roller is pushed and the lever rotates to detect its displacement, thereby detecting the torque during operation. When a driving bicycle 16 approaches a slope or the like and the driving torque due to human power exceeds a certain numerical value, the torque sensor 19 detects the torque and the electric control (not shown) is performed. By the function of the circuit, a current can be sent from the mounted battery 46 to the motor direct connection planetary roller speed reducer 30, and this current can be driven to assist human power. When the road becomes flat and the driving torque of the bicycle 16 becomes small, the torque sensor 19 stops transmitting to the auxiliary drive, the motorized reduction gear transmission 30 stops, and the bicycle 16 travels manually. Since the driven sprocket wheels 2 and 45 are mounted via the rear wheel shaft and the one-way clutch, they may interfere with each other during manual operation, during operation by the motored reduction gear transmission 30, and during inertial movement of the bicycle. There is no such thing.

[0009]

As described above in detail, since the present invention uses the planetary roller reducer, it has less vibration and noise than the gear type reducer. A sun roller is formed at the output shaft end of the thin motor, and a planetary roller speed reduction mechanism is configured on the rotation surface of the sun roller. The output shaft side is arranged in the space between the motor and The axial length of the entire mechanism combination can be shortened. When using this planetary roller reducer with motor as auxiliary power for the bicycle, the output chain sprocket is placed between the thin motor and the thin reducer, so the reducer does not travel, and the driven side sprocket does not need to travel significantly. It disappears and the installation is good. The speed reducer can be configured symmetrically with the chain as the center. A bearing for supporting a planet carrier is concentrically arranged inside the output sprocket wheel, and the bearing directly receives the tensile force of the chain applied to the output sprocket and receives bending stress like a cantilevered output shaft. Since the bearing has a small load capacity, there is no runout and the durability is improved.

[Brief description of drawings]

FIG. 1 is a side sectional view of a motor direct coupling planetary roller reducer according to an embodiment of the present invention.

2 is a front view showing an AA cross section of FIG. 1. FIG.

FIG. 3 is a side view showing a bicycle to which the speed reducer of FIG. 1 is attached.

FIG. 4 is an enlarged plan view showing a BB cross section of FIG. 3;

FIG. 5 is a side view showing an outline of a conventional bicycle power mechanism.

FIG. 6 is a plan view of the power mechanism of the bicycle shown in FIG.

FIG. 7 is a front view showing an example of the torque detector in FIG.

8 is a plan view of the torque detector of FIG. 7. FIG.

FIG. 9 is a side sectional view of a conventional motor direct coupling planetary gear reducer.

[Explanation of symbols]

 16 Bicycle with auxiliary power 17 Rear wheel 19 Torque sensor 30 Motor direct connection planetary roller speed reducer 31 Thin DC motor 32 Motor output shaft 32a Sun roller 33 Elastic ring or inner roller 34 Planetary roller 35 Planetary roller shaft 36 Planetary roller carrier 37 Output sprocket 38 Ball bearing 39 Chain 41 Reducer casing 41a Casing window 45 Driven sprocket 50 Bearing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiro Sakai No. 1 Takamichi, Iwazuka-cho, Nakamura-ku, Nagoya-shi Mitsubishi Heavy Industries, Ltd. Nagoya Machinery Works

Claims (2)

[Claims] 1. A thin motor having a mounting flange portion on the outer periphery of a casing and a sun roller formed at the tip of an output shaft,
Attached to the flange portion of the motor, the output shaft of the motor is supported by a small-diameter cylindrical portion on the inner side through a bearing, and a window for inserting an output chain is bored on a large-diameter cylindrical body portion on the outer side. A reducer casing in which an elastic ring or an inner roller is fitted concentrically with the motor shaft on the inner circumference of the end face of the body, and a plurality of planets circumscribing the sun roller at the tip of the motor output shaft and inscribed in the elastic ring or the inner roller. A roller, a planetary roller shaft that rotatably supports these planetary rollers, and a roller shaft that fixes and supports the roller shaft and is rotatably supported via a bearing on a small-diameter cylindrical portion inside the speed reducer casing to configure the output of the speed reducer. A planetary roller carrier, and an output sprocket wheel mounted on the planetary roller carrier. A bearing directly attached to the motor is arranged inside the output sprocket wheel disposed between the sun roller and the motor, and the bearing directly receives the pulling force of the chain applied to the output sprocket. Decelerator. 2. A bicycle having an auxiliary power mechanism, wherein the output sprocket of the planetary roller reducer directly coupled to the motor according to claim 1 is connected to a driven sprocket mounted on a rear wheel shaft via a chain.