JP2022057875A - Speed reduction device - Google Patents

Abstract

To provide a speed reduction device that can reduce the number of components, reduce manufacturing cost, and improve assembly workability.SOLUTION: A speed reduction device 1 comprises a sun rotation body 10, an annular body 40, a planetary rotation body 30, and a carrier 20. The sun rotation body rotates about a center axis J extending vertically. The annular body is arranged radially outside the sun rotation body. The planetary rotation body is in contact with an outer peripheral surface of the sun rotation body and an inner peripheral surface of the annular body, and revolves about the center axis. The carrier rotates about the center axis. The carrier comprises a carrier body 21 and a carrier pin 22. The carrier body is arranged axially above the sun rotation body. The carrier pin rotatably supports the planetary rotation body, and only an upper end part is connected to the carrier body.SELECTED DRAWING: Figure 1

Description

The present invention relates to a speed reducer.

The conventional speed reducer includes a sun gear, a planetary gear, a carrier shaft member, and a pair of carrier support members. The sun gear rotates around the central axis. The planetary gear revolves around the sun gear around the central axis. The carrier shaft member rotatably supports the planetary gears. The pair of carrier support members rotate about the central axis and fix the upper part and the lower part of the carrier shaft member. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-003985

However, the conventional speed reducer has a large number of parts, which may increase the manufacturing cost and reduce the assembly workability.

An object of the present invention is to provide a speed reducing device capable of reducing the number of parts, reducing the manufacturing cost, and improving the assembly workability.

An exemplary speed reducer of the present invention comprises a sun rotating body, an annular body, a planetary rotating body, and a carrier. The solar rotating body rotates about a central axis extending in the vertical direction. The annular body is arranged radially outside the solar rotating body. The planetary rotating body comes into contact with the outer peripheral surface of the solar rotating body and the inner peripheral surface of the annular body, and revolves around the central axis. The carrier rotates about a central axis. The carrier includes a carrier body and a carrier pin. The carrier body is arranged on the axially upper side of the solar rotating body. The carrier pin rotatably supports the planetary rotating body, and only the upper end thereof is connected to the carrier body.

According to an exemplary invention, it is possible to provide a speed reducing device capable of reducing the number of parts, reducing the manufacturing cost, and improving the assembly workability.

FIG. 1 is a vertical cross-sectional perspective view of the speed reducing device according to the first embodiment of the present invention. FIG. 2 is a perspective view showing a carrier and a planetary rotating body of the speed reducing device according to the first embodiment of the present invention. FIG. 3 is an enlarged vertical sectional view showing a part of the speed reducing device according to the second embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In the present specification, in the speed reducing device 1, the rotation axis of the solar rotating body 10 is referred to as "central axis J", and the direction parallel to the central axis J is referred to as "axial direction". Further, the direction orthogonal to the central axis J of the solar rotating body 10 is referred to as "diameter direction", and the direction along the arc centered on the central axis J of the solar rotating body 10 is referred to as "circumferential direction". Further, in the present application, the axial direction is set to the vertical direction, and the shape and positional relationship of each part will be described. It should be noted that the vertical direction is a name used only for explanation and does not limit the actual positional relationship and direction in the speed reducing device 1.

<First Embodiment>
<1. Overall configuration of speed reducer>
An exemplary embodiment of the speed reducer of the present invention will be described below. FIG. 1 is a perspective view of the speed reducing device 1 according to the present embodiment, and FIG. 2 is a perspective view showing a carrier 20 and a planetary rotating body 30. In FIGS. 1, 2, and 3, the tooth shapes of the sun tooth 10a, the internal tooth 40a, the first planet tooth 31a, and the second planet tooth 32a are not shown.

The speed reducing device 1 converts the rotational movement of the first rotation speed into the rotational movement of the second rotation speed lower than the first rotation speed. The speed reducing device 1 is incorporated and used in, for example, a drive mechanism of a robot, a machine tool, an electrically assisted bicycle, an electric wheelchair, or the like. However, the speed reducing device 1 of the present invention may be used for other purposes.

The speed reducing device 1 includes a solar rotating body 10, an annular body 40, a planetary rotating body 30, a carrier 20, a housing 50, and an output rotating body 70.

The housing 50 is a substantially cylindrical member, and houses the sun rotating body 10, the carrier 20, the planetary rotating body 30, and the annular body 40 inside. The housing 50 rotatably supports the solar rotating body 10 via the bearing portion 63. Further, the housing 50 rotatably supports the carrier 20 via the bearing portion 61.

The solar rotating body 10 rotates about a central axis J extending in the vertical direction. The solar rotating body 10 is connected to an input shaft (not shown). The input shaft is connected to a motor (not shown). When the motor is driven, the solar rotating body 10 rotates at the first rotation speed about the central axis J. The solar rotating body 10 has sun teeth 10a protruding radially outward from the radial outer surface.

The annular body 40 is an annular member arranged on the radial outer side of the solar rotating body 10. The annular body 40 is fixed to the housing 50 and has internal teeth 40a. The internal teeth 40a project radially inward from the radial inner surface of the annular body 40.

The planetary rotating body 30 comes into contact with the outer peripheral surface of the solar rotating body 10 and the inner peripheral surface of the annular body 40, and revolves around the central axis J.

The carrier 20 is connected to the upper end portion of the solar rotating body 10 via the bearing portion 62. As a result, the carrier 20 is rotatably supported relative to the solar rotating body 10 and the housing 50. Further, the carrier 20 rotatably supports the planetary rotating body 30. For the bearing portions 61, 62, 63, for example, ball bearings are used.

When the solar rotating body 10 rotates at the first rotation number, the plurality of planetary rotating bodies 30 rotate at a second rotation number lower than the first rotation number along the radial inner surface of the annular body 40. Revolve. When the plurality of planetary rotating bodies 30 revolve at the second rotation speed, the carrier 20 rotates at the second rotation speed about the central axis J.

The output rotating body 70 is a member having a covered cylinder shape and is fixed to the carrier 20. As a result, the output rotating body 70 rotates about the central axis J at the second rotation speed after deceleration.

<2. Detailed career structure>

The carrier 20 has a carrier main body 21, a carrier pin 22, a connecting portion 23, and a carrier bearing holding portion (carrier convex portion) 24.

The carrier main body 21 is formed in a disk shape and is arranged on the upper side in the axial direction of the solar rotating body 10. The carrier main body 21 is provided with three through holes 21a arranged at equal intervals in the circumferential direction on the outer peripheral portion. The through hole 21a penetrates the carrier main body 21 in the axial direction. The upper end of the carrier pin 22 is press-fitted into the through hole 21a.

The carrier pin 22 is a columnar member and connects the carrier main body 21 and the planetary rotating body 30. The carrier pin 22 is arranged substantially parallel to the central axis J. The carrier pin 22 is inserted inside a cylindrical portion 31 described later of the planetary rotating body 30, and rotatably supports the planetary rotating body 30 via a bearing portion (not shown) such as a ball bearing, for example. That is, the carrier pin 22 rotatably supports the planetary rotating body 30, and only the upper end thereof is connected to the carrier main body 21.

In contrast to the structure in which the upper carrier connects the upper end of the carrier pin and the lower carrier connects the lower end of the carrier pin as in the conventional speed reducer, the structure of the present embodiment is thus a carrier. The lower carrier that supports the lower end of the pin 22 can be omitted. At this time, the bearing portion that rotatably supports the lower carrier with respect to the solar rotating body 10 can also be omitted. Therefore, it is possible to provide the speed reducing device 1 which can reduce the number of parts, reduce the manufacturing cost, and improve the assembly workability.

The connecting portion 23 extends axially upward from the upper surface of the carrier main body 21 and is connected to the upper wall bearing holding portion 53a described later via the bearing portion 61. Further, the upper end portion of the connecting portion 23 is fixed to the output rotating body 70.

The carrier bearing holding portion 24 extends downward in the axial direction from the lower surface of the carrier main body 21, and is formed in a cylindrical shape surrounding the central axis J. The carrier bearing holding portion 24 holds the bearing portion 62.

<3. Detailed composition of the planetary revolution>
Three planetary rotating bodies 30 are arranged around the sun rotating body 10 at equal intervals. The planetary rotating body 30 has a cylindrical portion 31 and a planetary annular portion 32.

The tubular portion 31 has a carrier pin 22 arranged inside and is formed in a cylindrical shape. The tubular portion 31 has a first planetary tooth 31a protruding radially outward from the radial outer surface. The first planetary tooth 31a meshes with the internal tooth 40a of the annular body 40.

The planetary annular portion 32 extends radially outward from the lower portion of the tubular portion 31 and is formed in an annular shape. The planetary annular portion 32 has a second planetary tooth 32a protruding radially outward from the radial outer surface. The second planetary tooth 32a meshes with the sun tooth 10a. At this time, the planetary rotating body 30 comes into contact with the outer peripheral surface of the solar rotating body 10 and the inner peripheral surface of the annular body 40, and receives forces from the radial inner side and the radial outer side, respectively. This makes it possible to prevent the planetary rotating body 30 from tilting with respect to the carrier pin 22 arranged substantially parallel to the central axis J.

Further, the lower end of the carrier pin 22 is arranged between the lower end and the upper end of the planetary annular portion 32. This makes it possible to prevent the planetary rotating body 30 from tilting with respect to the carrier pin 22 due to the force received from the sun rotating body 10.

Further, the carrier bearing holding portion (carrier convex portion) 24 is arranged radially inside the tubular portion 31 and faces the tubular portion 31 in the radial direction via a gap. This makes it possible to prevent the carrier bearing holding portion 24 and the tubular portion 31 from sliding. Further, when the planetary rotating body 30 receives a force radially inward from the annular body 40 and tilts with respect to the carrier pin 22, the tubular portion 31 comes into contact with the carrier bearing holding portion 24. This makes it possible to prevent the planetary rotating body 30 from being greatly tilted with respect to the carrier pin 22.

<4. Detailed housing configuration>
The housing 50 has a peripheral wall portion 51, a bottom wall portion 52, and an upper wall portion 53. The peripheral wall portion 51 can be divided into upper and lower parts, and is formed in a cylindrical shape. The peripheral wall portion 51 is arranged radially outside the annular body 40 and holds the annular body 40.

In the present embodiment, the annular body 40 is composed of a member separate from the peripheral wall portion 51, but the annular body 40 is formed by the peripheral wall portion 51 by providing internal teeth 40a on the radial inner surface of the peripheral wall portion 51. May be good.

The bottom wall portion 52 extends radially inward from the lower end portion of the peripheral wall portion 51 and faces the lower portion of the planetary rotating body 30 in the axial direction. The bottom wall portion 52 has a bottom wall bearing holding portion 52a that holds the bearing portion 63.

The upper wall portion 53 extends radially inward from the upper end portion of the peripheral wall portion 51 and faces the upper portion of the planetary rotating body 30 in the axial direction. Further, the upper wall portion 53 has an upper wall bearing holding portion 53a for holding the bearing portion 61.

<Second Embodiment>
Next, a second embodiment of the present invention will be described. FIG. 3 is an enlarged perspective view showing a part of the speed reducing device 1 according to the second embodiment. For convenience of explanation, the same parts as those in the first embodiment shown in FIGS. 1 and 2 described above are designated by the same reference numerals. The second embodiment is different from the first embodiment in that the housing 50 has the first convex portion 81 and the second convex portion 82. Other parts are the same as those in the first embodiment.

The tubular portion 31 projects downward from the planetary annular portion 32. Further, the housing 50 has a first convex portion 81 and a second convex portion 82. The first convex portion 81 and the second convex portion 82 are formed in an annular shape so as to project upward in the axial direction from the upper surface of the bottom wall portion 52 and surround the central axis J. The first convex portion 81 is arranged radially outside the tubular portion 31, and the second convex portion 82 is arranged radially inside the tubular portion 31. The inner surface of the first convex portion 81 faces the lower end portion of the tubular portion 31 in the radial direction via a gap. The outer surface of the second convex portion 82 faces the lower end portion of the tubular portion 31 in the radial direction via a gap.

Further, on the upper surface of the bottom wall portion 52, the lubricant 83 is arranged in a region facing the tubular portion 31 in the axial direction. Specific examples of the lubricant 83 include liquid grease and slip washers. By providing the lubricant 83, the rotation and revolution of the planetary rotating body 30 become smooth.

By providing the first convex portion 81, when the planetary rotating body 30 receives a force radially outward from the sun rotating body 10 and tilts with respect to the carrier pin 22, the planetary annular portion 32 becomes the first convex portion. It is possible to prevent the planetary rotating body 30 from tilting significantly with respect to the carrier pin 22 by abutting on the portion 81.

Further, by providing the second convex portion 82, when the planetary rotating body 30 receives a force radially inward from the annular body 40 and tilts with respect to the carrier pin 22, the planetary annular portion 32 becomes the second. It is possible to prevent the planetary rotating body 30 from tilting significantly with respect to the carrier pin 22 by abutting on the convex portion 82.

In this embodiment, both the first convex portion 81 and the second convex portion 82 are provided, but one of the first convex portion 81 and the second convex portion 82 may be provided.

<4. Others>
The embodiment of the present invention has been described above. The scope of the present invention is not limited to the above-described embodiment. The present invention can be carried out with various modifications without departing from the gist of the invention. In addition, the above-described embodiments can be arbitrarily combined.

INDUSTRIAL APPLICABILITY The present invention can be used by being incorporated into a drive mechanism of, for example, a robot, a machine tool, an electrically assisted bicycle, or an electric wheelchair.

1 Deceleration device 10 Solar rotating body 10a Solar tooth 20 Carrier 21 Carrier body 21a Through hole 22 Carrier pin 23 Connecting part 24 Carrier bearing holding part (carrier convex part)
30 Planet of revolution 31 Cylindrical part 31a 1st planetary tooth 32 Planetary annular part 32a 2nd planetary tooth 40 annular body 40a Internal tooth 50 Housing 51 Peripheral wall part 52 Bottom wall part 52a Bottom wall bearing holding part 53 Upper wall part 53a Upper wall Bearing holding part 61, 62, 63 Bearing part 63 Solar rotating body 70 Output rotating body 81 First convex part 82 Second convex part 83 Lubricating material J Central axis

Claims (8)

A sun-rotating body that rotates around a central axis that extends in the vertical direction,
An annular body arranged radially outside the solar rotating body, a planetary rotating body that comes into contact with the outer peripheral surface of the solar rotating body and the inner peripheral surface of the annular body, and revolves around a central axis.
With a carrier that rotates about the central axis,
The carrier
A carrier body arranged on the upper side in the axial direction of the solar rotating body, and
A speed reducing device comprising a carrier pin that rotatably supports the planetary rotating body and has only an upper end portion connected to the carrier body. The planetary rotating body is
A cylindrical portion in which the carrier pin is arranged, and a tubular portion.
It has an annular planetary annular portion extending radially outward from the tubular portion.
The outer peripheral surface of the tubular portion comes into contact with the inner peripheral surface of the annular body,
The speed reducing device according to claim 1, wherein the outer peripheral surface of the planetary annular portion comes into contact with the outer peripheral surface of the solar rotating body. The speed reducing device according to claim 2, wherein the lower end of the carrier pin is arranged between the lower end and the upper end of the planetary annular portion. The carrier
It has a carrier convex portion that protrudes downward in the axial direction from the lower surface of the carrier body and is arranged radially inside the tubular portion.
The speed reducing device according to claim 2 or 3, wherein the carrier convex portion faces the tubular portion with a gap in the radial direction. A cylindrical peripheral wall portion arranged on the radial outer side of the annular body and holding the annular body,
Further comprising a housing having a bottom wall portion extending radially inward from the lower end portion of the peripheral wall portion and facing the lower portion of the planetary rotating body in the axial direction.
The tubular portion protrudes downward from the planetary annular portion and
The housing has a first convex portion that projects axially upward from the upper surface of the bottom wall portion.
The first convex portion is arranged radially outside the tubular portion and is an annular shape surrounding the central axis.
The speed reducing device according to any one of claims 2 to 4, wherein the inner surface surface of the first convex portion is radially opposed to the lower end portion of the tubular portion via a gap. The housing has a second convex portion that projects axially upward from the upper surface of the bottom wall portion.
The second convex portion is arranged radially inside the tubular portion and is an annular shape surrounding the central axis.
The speed reducing device according to claim 5, wherein the outer surface of the second convex portion is radially opposed to the lower end portion of the tubular portion via a gap. A cylindrical peripheral wall portion arranged on the radial outer side of the annular body and holding the annular body,
Further comprising a housing having a bottom wall portion extending radially inward from the lower end portion of the peripheral wall portion and facing the lower portion of the planetary rotating body in the axial direction.
The tubular portion protrudes downward from the planetary annular portion, and the tubular portion protrudes downward.
The housing has a second convex portion that projects axially upward from the upper surface of the bottom wall portion.
The second convex portion is arranged radially inside the tubular portion and is an annular shape surrounding the central axis.
The speed reducing device according to any one of claims 2 to 4, wherein the outer surface of the second convex portion is radially opposed to the lower end portion of the tubular portion via a gap. The speed reducing device according to any one of claims 1 to 7, wherein a lubricating material is arranged on the upper surface of the bottom wall portion in a region facing the cylindrical portion in the axial direction.

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