KR20220022451A - Speed reduction device and geared motor - Google Patents

Abstract

A speed reduction apparatus of one aspect of the present invention comprises: an internally toothed gear which is extended in an axial direction about a central axis; a first sun gear which is disposed inside the internally toothed gear and centered about the central axis; a first planetary gear which is meshed with the first sun gear and the internally toothed gear; and a first carrier which supports the first planetary gear to be rotatable from one side of the axial direction. The first carrier has a first facing surface that faces the planetary gear in the axial direction. On the first facing surface, a recessed unit is provided to overlap a passing trajectory of a tooth surface of the first planetary gear from the axial direction. The speed reduction apparatus reduces a size of the gear while securing strength of the gear.

Description

SPEED REDUCTION DEVICE AND GEARED MOTOR

The present invention relates to a reduction device and a geared motor.

BACKGROUND ART In recent years, with the precision of electronic devices such as smart phones, the development of geared motors having a smaller size and higher functions is progressing. As a geared motor, one in which a gearbox (reduction device) including a plurality of stages of a planetary gear reduction mechanism is connected to the motor is known (Patent Document 1).

Japanese Patent Laid-Open No. 2019-49325

In a reduction mechanism having a plurality of stages of a planetary gear mechanism, as it approaches the output side, the transmitted torque increases, and it is necessary to ensure the strength of each gear. On the other hand, it is required to reduce the tooth width of each gear from the necessity to pursue miniaturization. That is, in the reduction mechanism, it is calculated|required to achieve the intensity|strength securing of a gear and size reduction simultaneously.

One aspect of the present invention aims to provide a reduction device and a geared motor capable of realizing miniaturization while ensuring the strength of a gear.

A reduction device of one aspect of the present invention includes an internal gear extending in an axial direction about a central axis, a first sun gear disposed inside the internal gear and centered on the central axis, and the first sun A first planetary gear meshed with a gear and the internally toothed gear, and a first carrier for rotatably supporting the first planetary gear from one side in the axial direction. The first carrier has a first opposed surface axially opposed to the planetary gear. A concave portion is provided in the first opposing surface, which overlaps with the passage trajectory of the tooth surface of the first planetary gear as viewed from the axial direction.

The geared motor of one aspect of this invention has the speed reduction device mentioned above, and a motor main body. The speed reduction device is connected to the motor body.

According to one aspect of the present invention, a reduction device and a geared motor capable of realizing miniaturization while ensuring the strength of a gear are provided.

1 is a cross-sectional view of a geared motor according to an embodiment.
2 is an exploded perspective view of a geared motor according to an embodiment.
FIG. 3 is a partially enlarged view of FIG. 1 ;
4 is a perspective view of a first carrier according to an embodiment.
5 is a perspective view of a first carrier of a modified example;

EMBODIMENT OF THE INVENTION Hereinafter, the geared motor which concerns on embodiment of this invention is demonstrated, referring drawings. In addition, the scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention.

In the figure, the Z axis parallel to the central axis J is shown. In the following description, unless otherwise specified, the Z-axis direction is simply referred to as "axial direction" or "up-and-down direction", and the +Z side is referred to as "axial direction one-sided" or "upper side", and -Z side is called “the other side in the axial direction” or “the lower side”. In addition, the up-down direction in this specification is a direction set for convenience of description, and does not limit the attitude|position at the time of use of a geared motor. In addition, in the following description, the circumferential direction around the central axis J is simply called a "circumference direction", and the radial direction with respect to the central axis J is simply called a "radial direction."

<Geared Motor>

1 is a cross-sectional view of a geared motor 1 . 2 is an exploded perspective view of the geared motor 1 . The geared motor 1 includes a motor body 2 and a speed reduction device 3 connected to the motor body 2 . Hereinafter, each part of the geared motor 1 is demonstrated in detail.

<Motor body>

The motor body 2 has a cylindrical shape centered on the central axis J as a whole. In the present embodiment, the motor body 2 is a stepping motor.

As shown in FIG. 1 , the motor body 2 includes a rotor 21 and a stator 26 surrounding the rotor 21 from the radially outer side. Further, the motor body 2 has a motor shaft 22 fixed to the rotor 21 .

The motor shaft 22 extends in the axial direction about the central axis J. In the present embodiment, the motor shaft 22 protrudes upward from the motor body 2 . The motor shaft 22 rotates with the rotor around the central axis J. At the upper end of the motor shaft 22, a third sun gear 33a is fixed.

<Reducing device>

The speed reduction device 3 is located above the motor body 2 . The speed reduction device 3 is connected to the motor body 2 . The deceleration device 3 decelerates the motive power output from the motor body 2 . The reduction device 3 includes a first planetary gear mechanism 30A, a second planetary gear mechanism 30B, and a third planetary gear mechanism 30C. Power output from the motor body 2 is transmitted to the third planetary gear mechanism 30C, the second planetary gear mechanism 30B, and the first planetary gear mechanism 30A in this order, and the first planetary gear mechanism 30A ) is output in The third planetary gear mechanism 30C, the second planetary gear mechanism 30B, and the first planetary gear mechanism 30A are arranged in this order from the lower side to the upper side.

The reduction device 3 includes a gear housing 39 , a third sun gear 33a , three third planetary gears 33b , a third carrier 31 , and three second planetary gears 34b . ), a second carrier 32 , three first planetary gears 35b and a first carrier 36 . As will be described later, the gear housing 39 has an internally toothed gear 39a. In addition, the third carrier 31 has a second sun gear 31c. Similarly, the second carrier 32 has a first sun gear 32c.

The third sun gear 33a, the third planetary gear 33b, the third carrier 31, and the internally toothed gear 39a constitute the third planetary gear mechanism 30C. The second sun gear 31c, the second planetary gear 34b, the second carrier 32, and the internally toothed gear 39a constitute the second planetary gear mechanism 30B. The first sun gear 32c, the first planetary gear 35b, the first carrier 36, and the internally toothed gear 39a constitute the first planetary gear mechanism 30A.

The gear housing 39 has an internal gear 39a, a bottom part 39b, and a bearing part 39d. That is, the reduction gear 3 has the internal gear 39a. The internally toothed gear 39a is a cylindrical shape extending in the axial direction centering on the central axis J. The internally toothed gear 39a meshes with the third planetary gear 33b, the second planetary gear 34b, and the first planetary gear 35b. The bottom part 39b is located at the upper end of the internally toothed gear 39a. Seen from the axial direction, a bearing portion 39d is provided in the center of the bottom portion 39b. The bearing portion 39d extends from the bottom portion 39b upward in a cylindrical shape. The bearing portion 39d is a sliding bearing. The bearing part 39d rotatably supports the output part 36d mentioned later on an inner peripheral surface.

The third sun gear 33a is disposed below the first sun gear 32c and the second sun gear 31c (the other side in the axial direction) inside the internally toothed gear 39a. The third sun gear 33a is centered on the central axis J. The third sun gear 33a is fixed to the motor shaft 22 and rotates together with the motor shaft 22 about the central axis J.

The three third planetary gears 33b are arranged at equal intervals in the circumferential direction of the central axis J. The three third planetary gears 33b are disposed between the third sun gear 33a and the internally toothed gear 39a in the radial direction. The three third planetary gears 33b mesh with the third sun gear 33a and the internally toothed gear 39a. The three third planetary gears 33b orbit around the central axis J with rotation of the third sun gear 33a. In the center of the third planetary gear 33b, a holding hole 33ba that opens upward is provided.

The third carrier 31 has a third disk portion 31b, three third sub shafts 31a, and a second sun gear 31c. The third disk portion 31b extends in the radial direction with the central axis J as the center. The third disk portion 31b is located below the second planetary gear 34b and above the third planetary gear 33b. The third disk portion 31b is connected to the second sun gear 31c. The third disk portion 31b has a plate shape orthogonal to the central axis J. The third disk portion 31b is located above the third sun gear 33a and the third planet gear 33b. The three third sub shafts 31a extend downward from the third disk portion 31b. The second sun gear 31c extends upward from the third disk portion 31b with the central axis J as the center.

The third sub shaft 31a is inserted into the holding hole 33ba of the third planetary gear 33b. The three third sub shafts 31a each rotatably support the third planetary gear 33b. That is, the third carrier 31 rotatably supports the plurality of third planetary gears 33b from the upper side (one side in the axial direction). The third carrier 31 rotates about the central axis J with the orbital rotation of the three third planetary gears 33b.

The second sun gear 31c is disposed below the first sun gear 32c (the other side in the axial direction) inside the internally toothed gear 39a. The second sun gear 31c is centered on the central axis J. Since the second sun gear 31c is a part of the third carrier 31, it rotates about the central axis J with the orbital rotation of the third planetary gear 33b.

The three second planetary gears 34b are arranged at equal intervals in the circumferential direction of the central axis J. The three second planetary gears 34b are disposed between the second sun gear 31c and the internally toothed gear 39a in the radial direction. The three second planetary gears 34b mesh with the second sun gear 31c and the internally toothed gear 39a. The three second planetary gears 34b orbit rotate in the circumferential direction of the central axis J with the rotation of the second sun gear 31c. A holding hole 34ba that opens upward is provided in the center of the second planetary gear 34b.

The second carrier 32 has a second disk portion (disk portion) 32b , three second sub shafts 32a , and a first sun gear 32c . The second disk portion 32b extends in the radial direction with the central axis J as the center. The second disk portion 32b is located below the first planetary gear 35b and above the second planetary gear 34b. The second disk portion 32b is connected to the first sun gear 32c. The second disk portion 32b has a plate shape orthogonal to the central axis J. The second disk portion 32b is located above the second sun gear 31c and the second planet gear 34b. The three second sub shafts 32a extend downward from the second disk portion 32b. The first sun gear 32c extends upward from the second disk portion 32b with the central axis J as the center.

The second sub shaft 32a is inserted into the holding hole 34ba of the second planetary gear 34b. The three second sub shafts 32a each rotatably support the second planetary gear 34b. That is, the second carrier 32 supports the plurality of second planetary gears 34b so as to be orbitally rotatable around the central axis J. That is, the second carrier 32 rotatably supports the plurality of second planetary gears 34b from the upper side (one side in the axial direction). The second carrier 32 rotates about the central axis J with the orbital rotation of the three second planetary gears 34b.

The first sun gear 32c is disposed inside the internally toothed gear 39a. The first sun gear 32c is centered on the central axis J. Since the first sun gear 32c is a part of the second carrier 32, it rotates about the central axis J with the orbital rotation of the second planet gear 34b.

The three first planetary gears 35b are arranged at equal intervals in the circumferential direction of the central axis J. The three first planetary gears 35b are disposed between the first sun gear 32c and the internally toothed gear 39a in the radial direction. The three first planetary gears 35b mesh with the first sun gear 32c and the internally toothed gear 39a. The three first planetary gears 35b orbit rotate in the circumferential direction of the central axis J with the rotation of the first sun gear 32c. In the center of the first planetary gear 35b, a holding hole 35ba that opens upward is provided.

The 1st carrier 36 has the 1st disk part 36b, the three 1st sub shafts (sub shafts) 36a, and the output part 36d. The first disk portion 36b extends in the radial direction with the central axis J as the center. The first disk portion 36b has a plate shape orthogonal to the central axis J. The first disk portion 36b is located above the first sun gear 32c and the first planet gear 35b. The three first sub shafts 36a extend downward from the first disk portion 36b. The output portion 36d extends upward from the first disk portion 36b with the central axis J as the center.

The first sub shaft 36a is inserted into the holding hole 35ba of the first planetary gear 35b. The three first sub shafts 36a rotatably support the first planet gear 35b, respectively. That is, the first carrier 36 rotatably supports the plurality of first planetary gears 35b from the upper side (one side in the axial direction). The first carrier 36 rotates about the central axis J with the orbital rotation of the three first planetary gears 35b.

Since the output part 36d is a part of the 1st carrier 36, it rotates centering on the central axis J with the orbital rotation of the 1st planetary gear 35b. The output part 36d is a column shape centering on the central axis J. The output part 36d is rotatably supported by the bearing part 39d of the gear housing 39. As shown in FIG. The upper end of the output portion 36d protrudes upward from the upper end of the gear housing 39 . A pinion gear (not shown) or the like that transmits the power of the geared motor 1 to another mechanism is fixed to the upper end of the output unit 36d.

The first carrier 36 is provided with a through hole 36e extending along the central axis J. The through hole 36e is opened to the upper end surface of the output portion 36d and the lower end surface of the first disk portion 36b. The through hole 36e has a circular shape centering on the central axis J. The insertion shaft 50 is inserted into the through hole 36e. The upper end of the insertion shaft 50 protrudes from the upper end surface of the through hole 36e. The upper end of the insertion shaft 50 is rotatably supported by a bearing part (not shown). The insertion shaft 50 guides rotation about the central axis J of the output part 36d.

FIG. 3 is a partially enlarged view of FIG. 1 .

3, the upper end surface and the lower end surface of the 1st planetary gear 35b are flat surfaces, respectively. The first planetary gear 35b is disposed between the first disk portion 36b and the second disk portion 32b. The first disk portion 36b has a first opposed surface 36ba that is axially opposed to the first planetary gear 35b. The first opposing surface 36ba is a surface facing downward. The second disk portion 32b has a second opposing surface 32ba that is axially opposed to the first planetary gear 35b. The second opposing surface 32ba is a surface facing upward.

4 is a perspective view of the first carrier 36 .

As shown in FIG. 4 , from the first opposing surface 36ba, the first sub shaft 36a extends downward (the other side in the axial direction). In the first opposing surface 36ba, a concave portion 37 is provided around the first sub shaft 36a. That is, a plurality (three in this embodiment) of the concave portions 37 are provided in the first opposing surface 36ba.

The concave portion 37 has a circular shape centering on the first sub shaft 36a as viewed from the axial direction. The diameter of the concave portion 37 is larger than the diameter of the first sub shaft 36a. Accordingly, the concave portion 37 includes the first planetary gear 35b mounted on the first sub-shaft 36a as viewed from the axial direction.

According to this embodiment, the recessed part 37 overlaps with the passage locus|trajectory of the tooth surface of the 1st planetary gear 35b as seen from the axial direction. Thereby, it becomes possible to ensure large tooth width (a dimension along the axial direction of a tooth surface) of the 1st planetary gear 35b while suppressing that the axial dimension of the reduction gear 3 enlarges. As a result, the strength of the first planetary gear 35b can be increased by suppressing the surface pressure generated on the tooth surface of the first planetary gear 35b.

The recessed portion 37 has a bottom surface 37a facing downward (the other side in the axial direction). The bottom surface 37a is smoothly curved along the radial direction of the central axis J. Here, the pitch circle CV passing through the three first sub shafts 36a is assumed on the bottom surface 37a. The pitch circle CV passes through the center J2 of the three first sub shafts 36a. The pitch circle CV is an imaginary circle centered on the central axis J. The bottom surface 37a inclines upward (one side in the axial direction) from the pitch circle CV to the radial inner and outer sides of the central axis J with the pitch circle CV as the peak P.

The upper surface of the first planetary gear 35b may contact the lower surface 37a of the concave portion 37 of the first carrier 36 . According to this embodiment, since the bottom surface 37a is inclined, the upper end surface of the first planetary gear 35b contacts the bottom surface 37a only at the peak P of the inclination of the bottom surface 37a.

When viewed from the axial direction, a part of the first planetary gear 35b projects radially outward from the outer edge of the first disk portion 36b. In addition, when viewed from the axial direction, a part of the first planetary gear 35b overlaps the through hole 36e. For this reason, when the bottom surface 37a is flat, at the time of rotation of the 1st planet gear 35b, the tooth surface of the 1st planet gear 35b is on the outer edge or inner edge of the 1st disk part 36b. there is a risk of taking

According to the present embodiment, the bottom surface 37a is inclined in a direction away from the first planetary gear 35b as it faces upward from the outside and inside in the radial direction from the pitch circle CV. For this reason, a vertical gap is provided between the outer edge and inner edge of the first disk portion 36b and the first planetary gear 35b, so that the tooth surface of the first planetary gear 35b is the first disk portion 36b. ) can be suppressed from being caught on the outer edge and the inner edge. Thereby, smooth rotation of the 1st planet gear 35b can be implement|achieved, and the rotation efficiency of the 1st planet gear 35b can be improved.

According to this embodiment, the bottom surface 37a curves smoothly along the radial direction with the pitch circle CV being the peak P. For this reason, the contact of the upper end surface of the 1st planetary gear 35b and the bottom surface 37a becomes a line contact, and a contact area is suppressed, and sliding resistance can be reduced. In addition, since the bottom surface 37a is smoothly curved, sliding between the upper end surface and the bottom surface 37a of the first planetary gear 35b becomes smooth, and the rotational efficiency of the first planetary gear 35b can be increased.

According to the present embodiment, the bottom surface 37a is a smooth convex shape curved along the circumferential direction. The thickness of the first disk portion 36 is greatest in the pitch circle CV, and decreases toward the radially inner and outer sides of the central axis J1. That is, the rigidity of the 1st carrier 36 is high on the pitch circle CV in which the 1st sub-shaft 36a aligns. According to this embodiment, sufficient intensity|strength of each member can be ensured, realizing size reduction of the axial direction dimension of the speed reduction device 3 .

As shown in FIG. 3, the 2nd opposing surface 32ba of the 2nd disk part 32b opposes the lower end surface of the 1st planetary gear 35b in an up-down direction. On the outer edge of the second opposing surface 32ba, a tapered portion 32bb is provided which inclines downward (the other side in the axial direction) as it moves away from the central axis J.

When viewed from the axial direction, a part of the first planetary gear 35b projects radially outward from the outer edge of the second disk portion 32b. According to this embodiment, the outer edge of the second opposing surface 32ba is inclined in a direction away from the first planetary gear 35b along the radially outward direction. For this reason, a vertical gap is provided between the outer edge of the second disk portion 32b and the first planetary gear 35b, so that the tooth surface of the first planetary gear 35b is the outer side of the second disk portion 32b. It is possible to suppress being caught on the edge. Thereby, smooth rotation of the first planetary gear 35b can be realized, and the rotational efficiency of the first planetary gear 35b can be increased.

The second planetary gear 34b is disposed between the second disk portion 32b and the third disk portion 31b. The second disk portion 32b has a third opposing surface 32bc that is axially opposed to the second planetary gear 34b. The third opposing surface 32bc is a surface facing downward. The third disk portion 31b has a fourth opposing surface 31ba that is axially opposed to the second planetary gear 34b. The fourth opposing surface 31ba is a surface facing upward.

Protrusions 34bp are provided on the upper end surface and the lower end surface of the second planetary gear 34b. The protrusion 34bp extends in an annular shape with respect to the center of the second planetary gear 34b. The protrusion 34bp of the upper end surface of the second planetary gear 34b protrudes upward. On the other hand, the protrusion 34bp of the lower end surface of the second planetary gear 34b protrudes downward.

According to the present embodiment, the second planetary gear 34b contacts the third opposing surface 32bc and the fourth opposing surface 31ba in the protrusion 34bp. For this reason, it is possible to suppress that the tooth surface of the second planetary gear 34b comes into contact with the third opposed surface 32bc and the fourth opposed surface 31ba, and the rotational efficiency of the second planetary gear 34b is increased. can In addition, it is possible to suppress the generation of the sliding noise accompanying the contact of the tooth surfaces of the second planetary gear 34b.

The third planetary gear 33b is disposed between the third disk portion 31b and the motor body 2 . The third disk portion 31b has a fifth opposed surface 31bb axially opposed to the third planetary gear 33b. The fifth opposing surface 31bb is a surface facing downward. The motor body 2 has a sixth opposing surface 2a which is axially opposed to the third planetary gear 33b. The sixth opposing surface 2a is a surface facing upward.

Protrusions 33bp are provided on the upper end surface and the lower end surface of the third planetary gear 33b. The protrusion 33bp extends in an annular shape with respect to the center of the third planetary gear 33b. The protrusion 33bp of the upper end surface of the third planetary gear 33b protrudes upward. On the other hand, the protrusion 33bp of the lower end surface of the third planetary gear 33b protrudes downward.

According to the present embodiment, the third planetary gear 33b is in contact with the fifth opposing surface 31bb and the sixth opposing surface 2a in the protrusion 33bp. For this reason, it can suppress that the tooth surface of the 3rd planetary gear 33b contacts the 5th opposing surface 31bb and the 6th opposing surface 2a, and the rotational efficiency of the 3rd planetary gear 33b is improved. can In addition, it is possible to suppress the generation of the sliding noise accompanying the contact of the tooth surfaces of the third planetary gear 33b.

In the present embodiment, protrusions 34bp and 33bp are provided on the upper end surface and lower end surface of the second planetary gear 34b and the third planetary gear 33b. On the other hand, the upper end surface and the lower end surface of the 1st planetary gear 35b are flat surfaces in which the protrusion part is not provided. In addition, the total length in the axial direction of the 1st planetary gear 35b, the 2nd planetary gear 34b, and the 3rd planetary gear 33b is substantially equal. For this reason, the tooth width D2 of the 2nd planetary gear 34b and the tooth width D3 of the 3rd planetary gear 33b are smaller than the tooth width D1 of the 1st planetary gear 35b by the height of the protrusion parts 34bp, 33bp.

The motive power of the motor body 2 is reduced in this order by the third planetary gear mechanism 30C, the second planetary gear mechanism 30B, and the first planetary gear mechanism 30A. For this reason, the surface pressure applied to the tooth surface of the 1st planetary gear 35b becomes larger than the surface pressure applied to the tooth surface of the 2nd planetary gear 34b and the 3rd planetary gear 33b. According to the present embodiment, by making the tooth width D1 of the first planetary gear 35b larger than the tooth widths D2 and D3 of the second planetary gear 34b and the third planetary gear 33b, the first planetary gear 35b damage can be suppressed.

On the other hand, the rotation speed of the 2nd planetary gear 34b and the 3rd planetary gear 33b is faster than the rotation speed of the 1st planetary gear 35b. For this reason, the sliding sound resulting from the rotation of the second planetary gear 34b and the third planetary gear 33b becomes larger than the sliding noise caused by the rotation of the first planetary gear 35b. According to this embodiment, by providing protrusions 34bp and 33bp, respectively, on the upper end surface and lower end surface of the 2nd planetary gear 34b and the 3rd planetary gear 33b, the sliding sound emitted by the speed reducer 3 can be suppressed.

(variant example)

5 : is a perspective view of the 1st carrier 136 of the modification employable to the above-mentioned embodiment.

The configuration of the bottom surface 137a of the concave portion 137 is different from that of the first carrier 136 of the present modification compared with the above-described embodiment. In addition, about the component of embodiment and the same aspect mentioned above, the same code|symbol is attached|subjected, and the description is abbreviate|omitted.

The 1st carrier 136 of this modification has the 1st disk part 136b, the three 1st sub shafts 36a, and the output part 36d similarly to embodiment mentioned above. The first sub shaft 36a rotatably supports the first planetary gear 35b. The first disk portion 136b has a first opposing surface 136ba facing downward. The first opposing surface 136ba faces the first planetary gear 35b in the axial direction. The first sub shaft 36a extends downward from the first opposed surface 136ba. A concave portion 137 is provided on the first opposing surface 136ba, which overlaps with the passage trajectory of the tooth surface of the first planetary gear 35b as viewed from the axial direction. The recessed portion 137 has a bottom surface 137a facing downward (the other side in the axial direction). The bottom surface 137a has a circular shape centering on the first sub shaft 36a as viewed from the axial direction.

In the present modification, the bottom surface 137a is inclined upward as it moves away from the first sub shaft 36a. That is, the bottom surface 137a has a tapered shape centering on the center J2 of the first sub shaft 36a. According to this modification, the bottom surface 137a is in contact with the first planetary gear 35b in the vicinity of the base end of the first sub shaft 36a. Accordingly, a vertical gap is provided between the bottom surface 137a and the tooth surface of the first planetary gear 35b so that the tooth surface of the first planetary gear 35b is the outer edge and the inner edge of the first disk portion 136b. can be prevented from getting caught. Thereby, smooth rotation of the first planetary gear 35b can be realized, and the rotational efficiency of the first planetary gear 35b can be increased.

According to this modification, the first disk portion 136b becomes thicker as it approaches the first sub shaft 36a. For this reason, in the base end of the 1st sub shaft 36a, the rigidity of the 1st disk part 136b can be improved.

In addition, the bottom surface 137a of this modification may have the shape of a conical surface with a fixed inclination angle, or the dome shape curved smoothly by changing the inclination angle may be sufficient as it.

As mentioned above, although embodiment and modification of this invention were described, each structure in an embodiment, their combination, etc. are an example, and within the range which does not deviate from the meaning of this invention, addition, omission, substitution and Other changes are possible. In addition, this invention is not limited by embodiment.

For example, in the above-described embodiment, in the first, second, and third planetary gear mechanisms 30A, 30B, and 30C, when the internal gear is fixed and the power input from the sun gear is output from the carrier, explained about it. However, the planetary gear mechanism employed in the reduction device may input from any and output from any as long as the internally toothed gear, the sun gear, and the carrier rotate relatively. For example, the carrier may be fixed and the motive power input from the sun gear may be output from an internal gear. Moreover, it may have a transmission mechanism which changes the reduction ratio by switching the output part.

Further, in the present embodiment, the motor main bodies 20A and 20B are stepping motors. However, as the motor body, a motor having a different configuration may be employed.

1: geared motor
2: Motor body
3: reduction gear
31: third carrier
31c: second sun gear
32: second carrier
32b: second disc part (disc part)
32ba: second opposing surface
32bb: tapered part
32c: first sun gear
33a: third sun gear
33b: third planetary gear
33bp, 34bp: Doljobu
34b: second planetary gear
35b: first planetary gear
36, 136: first carrier
36a: first sub shaft (sub shaft)
36ba, 136ba: first opposing surface
37, 137: concave
39a: internal gear
D1, D2, D3: tooth width
J: center axis
J2: center
P: peak
CV: Pitch One

Claims (9)

an internally toothed gear extending in an axial direction about the central axis;
a first sun gear disposed inside the internal gear and centered on a central axis;
a first planetary gear meshing with the first sun gear and the internally toothed gear;
and a first carrier for rotatably supporting the first planetary gear from one side in the axial direction;
The first carrier has a first opposing surface facing the first planetary gear in an axial direction,
A concave portion is provided on the first opposed surface, which overlaps with the passage trajectory of the tooth surface of the first planetary gear as viewed from the axial direction;
reduction gear. The method according to claim 1, wherein the first carrier has a sub-shaft extending and protruding from the first opposing surface to the other side in the axial direction to support the first planetary gear,
A surface of the concave portion facing the other side of the axial direction is smoothly curved along the radial direction of the central axis, and a pitch circle passing through the sub-shaft with the central axis as a center is a peak in the radial direction of the central axis. Inclined to one side in the axial direction as it faces inward and outward,
reduction gear. The method according to claim 1, wherein the first carrier has a sub-shaft extending and protruding from the first opposing surface to the other side in the axial direction to support the first planetary gear,
A surface facing the other axial side of the recess is inclined to one axial side as it moves away from the sub-shaft,
reduction gear. According to any one of claims 1 to 3, wherein the first planetary gear has a disk portion located on the other side in the axial direction connected to the first sun gear,
The disc part has a second opposing surface facing the first planetary gear in an axial direction,
An outer edge of the second opposing surface is provided with a tapered portion inclined to the other side in the axial direction as it moves away from the central axis,
reduction gear. The method according to any one of claims 1 to 3, further comprising: a second sun gear disposed inside the internal tooth gear on the other axial side of the first sun gear and centered on the central axis;
a second planetary gear meshing with the second sun gear and the internally toothed gear;
Further comprising a second carrier for rotatably supporting the second planetary gear from one side in the axial direction,
A protrusion portion is provided on an end surface of one axial direction of the second planetary gear, which extends in an annular shape with respect to the center of the second planetary gear and protrudes upward.
reduction gear. The method of claim 5, wherein the tooth width of the second planetary gear is smaller than that of the first planetary gear,
reduction gear. The method according to claim 5, wherein the third sun gear is disposed inside the internal tooth gear on the other side in the axial direction of the second sun gear and has the central axis as its center;
a third planetary gear meshing with the third sun gear and the internally toothed gear;
Further comprising a third carrier for rotatably supporting the third planetary gear from one side in the axial direction,
A protrusion is provided on one end surface of the third planetary gear in the axial direction, which extends in an annular shape with respect to the center of the third planetary gear and protrudes upward.
reduction gear. The method of claim 7, wherein the tooth width of the third planetary gear is smaller than that of the first planetary gear,
reduction gear. The reduction device according to any one of claims 1 to 3;
having a motor body,
The speed reduction device is connected to the motor body,
geared motor.

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