JP2021085504A - Housing, planetary gear drive, and actuator - Google Patents

Abstract

To provide a housing which reduces a number of components to facilitate assembly work and achieve reduction of assembly costs while inhibiting occurrence of noise and vibration during use.SOLUTION: A housing is formed into a cylindrical shape and has an internal gear part, which engages with a gear of a gear mechanism housed therein and forms a part of the gear mechanism, on its inner peripheral surface. The housing has: the internal gear part; and a cylindrical body part which is provided so as to enclose an outer periphery of the internal gear part. A gap part extending in an axial direction of the housing is provided between the internal gear part and the body part. The internal gear part and the body part are integrally provided by a connection part which partitions the gap part.SELECTED DRAWING: Figure 2

Description

The present invention relates to housings, planetary gears and actuators.

Conventionally, various mechanical devices have a planetary gear device incorporated as a speed reducer for decelerating and outputting the input rotation (see Patent Document 1). The planetary gear device disclosed in Patent Document 1 has a sun gear, an internal gear, a plurality of planetary gears, and a carrier in a housing.

The sun gear has external teeth on the outer peripheral surface. Such a sun gear rotates integrally with the output shaft of the electric motor. The internal gear has internal teeth on the inner peripheral surface. Each of the plurality of planetary gears has external teeth on the outer peripheral surface, and is provided between the sun tooth portion and the internal gear.

The external teeth of each planetary gear mesh with the external teeth of the sun gear and the internal teeth of the internal gear. Each such planetary gear rotates around its own central axis and revolves around the central axis of the sun gear based on the rotation of the sun gear. The carrier transmits the revolution of the planetary gear as an output to a member provided after the planetary gear device.

In such a planetary gear device, since a plurality of gears are combined and configured, noise and vibration are generated during operation due to, for example, backlash (gap in the meshing portion between the gears).

As a countermeasure, for example, in the planetary gear device of Patent Document 1, by forming the internal gear and the housing separately and fitted, it becomes difficult for vibration to be transmitted from the internal gear to the housing, which is caused by the vibration. The generation of noise is suppressed.

Special Fair 6-74835 Gazette

However, in the planetary gear device of Patent Document 1, since the internal gear and the housing are separated, vibration is less likely to be transmitted from the internal gear to the housing, and noise due to the vibration is less likely to be generated, but the number of parts is increased. The number increases, the assembly becomes complicated, and there arises a problem that the assembly workability deteriorates.

An object of the present invention is to provide a housing, a planetary gear device, and an actuator capable of reducing the number of parts, facilitating assembly work, and reducing assembly cost while suppressing the generation of noise and vibration during use. It is to be.

One aspect of the housing according to the present invention is
A housing that is formed in a tubular shape and has an internal gear portion that meshes with a gear of a gear mechanism housed inside and forms a part of the gear mechanism on the inner peripheral surface.
With the internal gear
It has a tubular main body portion provided so as to surround the outer circumference of the internal gear portion, and has a tubular main body portion.
A gap portion extending in the axial direction of the housing is provided between the internal gear portion and the main body portion.
The internal gear portion and the main body portion are integrally provided by a connecting portion that partitions the gap portion.

One aspect of the planetary gear device according to the present invention is
With the housing of the above configuration
A configuration is adopted in which the gear is housed in the housing and has a planetary gear mechanism having a planetary gear that meshes with the internal gear portion as the gear.

One aspect of the actuator according to the present invention includes an electric motor and a speed reducer for decelerating the rotation of the electric motor. The speed reducer is the above-mentioned planetary gear device, and the sun gear included in the planetary gear device. Is connected to the output shaft of the electric motor.

According to the present invention, it is possible to reduce the number of parts, facilitate the assembly work, and reduce the assembly cost while suppressing the generation of noise and vibration during use.

It is a main part exploded view of the actuator which incorporated the planetary gear device which concerns on Embodiment 1. FIG. It is a vertical sectional view of the actuator. It is an exploded view which shows the main part structure of a planetary gear device. FIG. 4A is a front view of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line ABC of FIG. 4A. FIG. 5A is a front view of a modified example 1 of a housing of a planetary gear device according to an embodiment of the present invention, and FIG. 5B is a cross-sectional view taken along the line DEF of FIG. 4A. FIG. 6A is a front view of a modified example 2 of a housing of a planetary gear device according to an embodiment of the present invention, and FIG. 6B is a sectional view taken along line GHJ of FIG. 6A. FIG. 7A is a front view of a modified example 3 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 7B is a sectional view taken along line KK of FIG. 7A. FIG. 8A is a front view of a modified example 4 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 8B is a sectional view taken along line LL of FIG. 8A. 9A is a front view of a modified example 5 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 9B is a cross-sectional view taken along the line MM of FIG. 9A.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The planetary gear device and actuator according to the embodiment described later are examples of the planetary gear device and actuator according to the present invention, and the present invention is not limited to the embodiment described later. Further, in order to facilitate understanding of the drawings, in each drawing, Cartesian coordinates having an X-axis parallel to the axial direction of the actuator 1 according to the embodiment of the present invention and a Y-axis and a Z-axis orthogonal to the X-axis. The system (X, Y, Z) is illustrated. That is, the X-axis direction is the other side of the actuator (the output side of the driving force of the actuator), but the Y-axis direction and the Z-axis direction may be used.

The actuator 1 according to the first embodiment and the planetary gear device 3 incorporated in the actuator 1 will be described with reference to FIGS. 1 to 4.

<Actuator configuration>
The actuator 1 shown in FIGS. 1 and 2 is used, for example, as an actuator for an electric back door for an automobile. However, the application of the actuator 1 is not particularly limited.

The actuator 1 has a motor (electric motor) 2 and a planetary gear device 3 connected to the motor 2. In the following description, the axial direction of each component means a direction parallel to the central axis of each member, and is an X-axis direction or a direction parallel to the X-axis. Further, one side in the axial direction is the −X axis direction side, for example, corresponds to the left side in FIGS. 1 and 2, and the other side (output direction side) in the axial direction is the + X axis direction, for example, FIG. And corresponds to the right side in FIG.

<Motor>
As shown in FIGS. 1 and 2, the motor 2 has a motor body 21 and a rotating shaft 22. The motor 2 operates under the control of a control unit (not shown) to rotate the rotating shaft 22 to drive the planetary gear device 3.

<Overall configuration of planetary gear device 3>
The planetary gear device 3 decelerates the rotation input by the motor 2 shown in FIGS. 1 and 2 at a predetermined reduction ratio and outputs the rotation from the output shaft 87.

As shown in FIGS. 1 and 2, the planetary gear device 3 includes, for example, a connecting lid 31, a housing 4, and a planetary gear mechanism 6 housed inside the connecting lid 31 and the housing 4. As shown in FIGS. 1 to 3, for example, the planetary gear mechanism 6 includes a plurality of planetary gear mechanisms (first planetary gear mechanism 7 and second planetary gear mechanism 8) arranged along the axial direction, and an output shaft. Has 87 and. Further, in the present embodiment, as shown in FIGS. 1 and 2, the housing 4 accommodates a plurality of planetary gear mechanisms 7 and 8 connected as the planetary gear mechanism 6 to realize a plurality of stages of deceleration. There is. In the housing 4 of the present embodiment, the planetary gear mechanism 6 decelerates the rotation of the rotating shaft 22 driven by the motor 2 in two steps and outputs the speed from the output shaft 87.

<Connecting lid 31>
The connection lid 31 is, for example, a member for attaching the motor 2 to the planetary gear device 3. Further, the connecting lid 31 is combined with the housing 4 to form an accommodating space for accommodating the planetary gear mechanism 6 inside. An opening 31a for passing the rotating shaft 22 of the motor 2 is formed in the center of the connecting lid 31. The rotating shaft 22 passed through the opening 31a is fixed to the sun gear 71 described later of the planetary gear mechanism 6. The connecting lid 31 is made of, for example, a synthetic resin and is molded by injection molding.

<Housing 4>
As shown in FIG. 2, the housing 4 is open on one side (−X direction side) in the axial direction to which the connecting lid 31 is attached, and the planetary gear mechanism 6 is housed from this opened portion. ing.

The housing 4 contains a first housing element 40 in which the first planetary gear mechanism 7 is housed, a second planetary gear mechanism 8 is housed in the housing 4, and the output shaft 87 of the second planetary gear mechanism 8 is projected to the outside. It has a housing element 50 and. The housing 4, specifically, the first housing element 40 and the second housing element 50 are made of, for example, synthetic resin and are molded by injection molding.

The first housing element 40 and the second housing element 50 are both ring-shaped first housing elements provided so as to surround the sun gears 71 and 81 and the plurality of planetary gears 72 and 82 (see FIGS. 2 and 3) described later. It has one internal gear 46 and a second internal gear 56, respectively. The first housing element 40 corresponds to an example of the housing of the present invention.

<First housing element 40>
FIG. 4 is a diagram provided for explaining the first housing element 40 in the housing of the planetary gear device according to the embodiment of the present invention. Specifically, FIG. 4A is a front view of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 4B is a cross-sectional view taken along the line ABC of FIG. 4A. The portion indicated by the dot in FIG. 4A is the gap portion 48, which is shown in the first housing element for convenience so as to be easily distinguished from the solid portion filled with meat. The hatching in FIG. 4B shows a cross section. Further, FIGS. A and B of FIGS. 5 to 9 showing this modification are also shown by dots and hatching in the same meaning.

The first housing element 40 is a tubular body and is open on one side (−X direction side), and is continuously provided on the second housing element 50 by the opening end surface portion 40a on the other side (X direction side). There is. In the present embodiment, the first housing element 40 and the second housing element 50 are integrally formed, and the hollow interiors of the first housing element 40 and the second housing element 50 communicate with each other to form a storage space for the planetary gear mechanism 6.

An engaging portion 42 that engages and is fixed to the connecting lid 31 is provided at the opening edge portion on one side of the first housing element 40. In the present embodiment, the engaging portion 42 is a claw portion that protrudes from the opening edge portion at a predetermined interval in the circumferential direction. By engaging the claw portion with the engaged portion provided on the connecting lid body 31, the relative movement of the connecting lid body 31 and the housing 4 in the axial direction and the circumferential direction is restricted.

In the present embodiment, the first housing element 40 of the housing 4 is connected to the first cylindrical body (main body portion) 44, the first internal gear 46, and the gap portion 48, as shown in FIGS. 2 and 4. It has a part 49 and. In the present embodiment, the first cylindrical body 44, the first internal gear 46, and the gap portion 48 are provided so as to extend in the axial direction of the housing 4 or the planetary gear mechanism 6, and are provided in the first cylindrical body 44 and the first inner portion. The gear 46 is connected to the first housing element 40 by an open end face portion 40a. The opening end face portion 40a is provided so as to be connected to each of the first cylindrical body 44 and the first internal gear 46 at the other end portion in the axial direction. In the present embodiment, the open end face portion 40a is provided integrally with the end portion on one side (−X direction side) of the second cylindrical body 54 of the second housing element 50. The opening end face portion 40a may have a function of partitioning the gap portion 48 on the other side (X direction side) in the axial direction and integrally connecting the first cylindrical body 44 and the first gear 46.

The first cylindrical body 44 is provided so as to surround the first internal gear 46 in addition to the sun gear 71, the planetary gear 72, and the carrier 73 constituting the first planetary gear mechanism 7. The first cylindrical body 44 has an outer peripheral surface 44a surrounding the sun gear 71, the planetary gear 72, the carrier 73, and the first internal gear 46, and this outer peripheral surface is the outer peripheral surface of the housing 4 together with the outer peripheral surface of the second housing element 50. Make up the face.

An engaging portion 42 is provided at the opening edge portion on one side of the first cylindrical body 44, and the opening edge portion on the other side is provided continuously and integrally with the second cylindrical body 54 of the second housing element 50. ..

Inside the first cylindrical body 44, a first internal gear 46 is provided via a gap 48.

The first internal gear 46 has a ring shape arranged so as to surround the planetary gear 72, and an internal tooth portion 46a is formed on the inner peripheral surface.

The internal tooth portion 46a has, for example, a spiral tooth cut diagonally with respect to the axis of the first internal gear 46, and the first internal gear 46 is a so-called helical gear.

The diameter of the tooth tip circle of the first internal gear 46 is larger than the diameter of the cylindrical carrier 73. A carrier 73 holding the planetary gear 72 is housed inside the first internal gear 46, and meshes with the planetary tooth portion 72a protruding from the outer peripheral surface of the carrier 73.

The gap portion 48 is provided in the first housing element 40 between the first internal gear 46 and the first cylindrical body 44 so as to extend in the axial direction of the housing 4.

The gap portion 48 is a lightening portion provided between the inner peripheral surface of the first cylindrical body 44 and the outer peripheral surface of the first internal gear 46, and has a diameter of the first internal gear 46 and the first cylindrical body 44. It is provided so as to be separated in the direction.

In the present embodiment, a plurality of gap portions 48 are provided in the circumferential direction between the inner peripheral side of the first cylindrical body 44 and the outer peripheral side of the first internal gear 46. In the present embodiment, the connecting portions 49 are arranged between the gap portions 48 arranged in the circumferential direction.

The connecting portion 49 connects the first cylindrical body 44 and the first internal gear 46, which are radially separated by the gap portion 48, in the radial direction. The connecting portion 49 extends in a direction intersecting the outer peripheral surface of the first internal gear 46 and the inner peripheral surface of the first cylindrical body 44 in the axial direction, and partitions the gap portion 48. The connecting portion 49 integrally connects the first internal gear 46 and the first cylindrical body 44.

In the present embodiment, as shown in FIG. 4, the connecting portion 49 projects radially outward from the outer peripheral surface of the first internal gear 46, is joined to the inner peripheral surface of the first cylindrical body 44, and has a shaft. It is formed in a rib shape extending in the direction.

In the present embodiment, the connecting portions 49 are provided on the outer circumference of the first internal gear 46 at equal intervals over the entire circumference.

As a result, the first internal gear 46 is not connected to the first cylindrical body 44 in the radial direction over the entire circumference on the outer peripheral side thereof, but is connected to the first cylindrical body 44 via the connecting portion 49. There is.

That is, in the housing 4, the tubular first housing element 40 is arranged on the inner peripheral side so as to surround the sun gear 71 and the planetary gear 72 of the first planetary gear mechanism 7. The first housing element 40 has a gap portion 48 between the internal tooth portion 46a of the first internal gear 46 on the inner peripheral side and the outer peripheral surface 44a of the first cylindrical body 44. Due to the gap portion 48, the first internal gear 46 is not continuous with the outer peripheral surface 44a of the first cylindrical body 44 on the entire circumference on the outer peripheral side, but has a structure that is partially continuous via the connecting portion 49. .. As a result, the vibration generated on the first internal gear 46 side when the planetary gear device 3 is operated is radially outward from the first internal gear 46, that is, on the outer peripheral surface side of the first cylindrical body 44. Transmitted by 49. That is, the vibration on the side of the first internal gear 46 is not transmitted from the entire circumference of the outer circumference of the first internal gear 46 to the outer peripheral surface 44a.

<Second housing element 50>
In the present embodiment, the second housing element 50 of the housing 4 has a second cylindrical body 54, a second internal gear portion 56 formed on the inner wall of the second cylindrical body 54, and an opening, as shown in FIG. It has a closing portion 57. In the present embodiment, the second internal gear portion 56 is carved diagonally at an angle with respect to the axial direction, and constitutes a so-called helical gear.

The opening closing portion 57 is connected to the other end of the second cylinder 54 so as to close the opening on the other side of the second cylinder 54. The opening closing portion 57 is formed in an annular shape, and has a tubular portion 57a for passing the output shaft 87 of the planetary gear mechanism 6 shown in FIGS. 1 to 3 so as to surround the central opening. The torque output from the output shaft 87 can be transmitted to an external mechanism via the tubular portion 57a.

<Planetary gear mechanism 6>
As shown in FIG. 2, the planetary gear mechanism 6 is housed in the housing 4 and decelerates the rotation transmitted from the motor 2 to output from the output shaft 87. The planetary gear mechanism 6 has a first planetary gear mechanism 7 and a second planetary gear mechanism 8 arranged along the axial direction.

<1st planetary gear mechanism 7>
As shown in FIGS. 2 and 3, the first planetary gear mechanism 7 rotates the sun gear 71, a plurality of planetary gears 72 arranged around the sun gear 71 in the center, and a plurality of planetary gears 72. A carrier 73 that supports the carrier 73 and a first internal gear 46 are provided. The first planetary gear mechanism 7 may include one or more planetary gears 72, but in the present embodiment, the first planetary gear mechanism 7 includes three planetary gears 72. In FIG. 3, for convenience of the perspective view, only two planetary gears 72 are shown, but another planetary gear 72 is provided at a position hidden behind the carrier 73 on the back side.

The sun gear 71 is an external gear having a sun tooth portion 71a formed on its outer peripheral surface, is connected to the rotating shaft 22 of the motor 2, and can rotate in a coaxial center with the rotating shaft 22. The sun gear 71 is rotated by the drive of the motor 2. In the present embodiment, the sun tooth portion 71a has a spiral tooth cut diagonally with respect to the axis of the sun gear 71, and the sun gear 71 of the present embodiment is a so-called helical gear. is there.

The planetary gear 72 is an external gear having a planetary tooth portion 72a formed on the outer peripheral surface thereof. The plurality of planetary gears 72 are arranged at equal intervals between the sun gear 71 and the first internal gear 46, and mesh with both the sun gear 71 and the first internal gear 46. In the present embodiment, the plurality of planetary gears 72 are arranged on the same circle centered on the axis of the first planetary gear mechanism 7, and are rotatably supported by the carrier 73. In the present embodiment, the planetary tooth portion 72a has a spiral tooth cut diagonally with respect to the axis of the planetary gear 72, and the planetary gear 72 of the present embodiment is a so-called helical gear. is there.

Each of the planetary gears 72 rotates about its own central axis (planetary axis 76) based on the rotation of the sun gear 71. Further, each of the planetary gears 72 revolves around the sun gear 71 based on its own rotation and meshing with the first internal gear 46. The central axis of revolution of the planetary gear 72 may coincide with the central axis of the sun gear 71.

The carrier 73 rotatably (rotates) the planetary gear 72. In addition, the carrier 73 rotates based on the revolution of the planetary gear 72, and transmits the rotation to the second planetary gear mechanism 8. Further, as shown in FIG. 3, the carrier 73 is formed in a cylindrical shape in the present embodiment, and the planetary gear 72 is accommodated in the accommodating opening 73a formed on the outer peripheral surface thereof. Each of the planetary gears 72 is rotatably supported by an axially oriented planetary shaft 76 within the accommodation opening 73a. In the present embodiment, the planetary gear 72 is attached in a state in which a part of the planetary gear 72 protrudes outward in the radial direction from the accommodating opening 73a and protrudes from the outer peripheral surface of the carrier 73. As a result, the planetary tooth portion 72a meshes with the internal tooth portion 46a of the first internal gear 46 (see FIG. 2).

<2nd planetary gear mechanism 8>
The second planetary gear mechanism 8 decelerates the rotation transmitted from the first planetary gear mechanism 7 at a predetermined reduction ratio and outputs the rotation. The second planetary gear mechanism 8 is provided on the other side (the right side in FIG. 2, the output side) in the axial direction from the first planetary gear mechanism 7. The second planetary gear mechanism 8 is arranged in the accommodation space of the housing 4 in the second housing element 50 of the housing 4, specifically, in the portion corresponding to the second internal gear portion 56. The second planetary gear mechanism 8 may be omitted.

In the present embodiment, the second planetary gear mechanism 8 includes a sun gear 81, a planetary gear 82, a carrier 83 that rotatably supports the planetary gear 82, and an output shaft 87. The second planetary gear mechanism 8 may include one or more planetary gears 82, but in the present embodiment, it includes three planetary gears 82. In FIG. 3, only two planetary gears 82 are shown for convenience of perspective view, but another planetary gear 82 is provided at a position hidden behind the carrier 83 on the back side.

The sun gear 81 is an external gear and has a sun tooth portion 81a on the outer peripheral surface. In the present embodiment, the sun tooth portion 81a has a spiral tooth cut diagonally with respect to the central axis of the sun gear 81, and the sun gear 81 is a so-called helical gear.

In the present embodiment, the sun gear 81 is fixed to the carrier 73 of the first planetary gear mechanism 7 in a state where the axes of the sun gear 81 are aligned with each other. As a result, the sun gear 81 rotates in conjunction with the rotation of the carrier 73 of the first planetary gear mechanism 7 as the carrier 73 of the first planetary gear mechanism 7 rotates.

That is, the sun gear 81 rotates in the same rotation direction as the carrier 73 of the first planetary gear mechanism 7 and at the same rotation speed as the carrier 73 of the first planetary gear mechanism 7 as the carrier 73 of the first planetary gear mechanism 7 rotates. Rotate.

The planetary gear 82 is an external gear having a planetary tooth portion 82a formed on the outer peripheral surface thereof. The plurality of planetary gears 82 are arranged at equal intervals between the sun gear 81 and the second internal gear portion 56, and mesh with both the sun gear 81 and the second internal gear portion 56. In the present embodiment, the plurality of planetary gears 82 are arranged on the same circle centered on the axis of the second planetary gear mechanism 8, and are rotatably supported by the planetary axis 86 of the carrier 83. In the present embodiment, the planetary tooth portion 72a has a spiral tooth cut diagonally with respect to the axis of the planetary gear 82, and the planetary gear 82 of the present embodiment is a so-called helical gear. is there.

Each of the planetary gears 82 rotates about its own central axis (planetary axis 86) based on the rotation of the sun gear 81. Further, each of the planetary gears 82 revolves around the sun gear 81 based on its own rotation and meshing with the second internal gear portion 56. The central axis of revolution of the planetary gear 82 may coincide with the central axis of the sun gear 81.

The carrier 83 rotatably supports the planetary gear 82 (rotates). In addition, the carrier 83 rotates based on the revolution of the planetary gear 82 and transmits the rotation to the output shaft 87.

In the present embodiment, the carrier 83 has a gear holding unit 84 and an output holding unit 85 that holds the output shaft 87.

The gear holding portion 84 holds the planetary gear 82 and is formed in a cylindrical shape. An accommodating opening 84a is formed on the outer peripheral surface of the gear holding portion 84, and the planetary gear 82 is accommodated in the accommodating opening 84a. Each of the planetary gears 82 is rotatably supported by an axially oriented planetary shaft 86 within the accommodation opening 84a. In the present embodiment, the planetary gear 82 is attached in a state in which a part of the planetary gear 82 protrudes outward in the radial direction from the accommodation opening 84a and protrudes from the outer peripheral surface of the carrier 83. As a result, the planetary tooth portion 82a meshes with the tooth portion 56a of the second internal gear portion 56.

The output holding portion 85 is continuously provided on the gear holding portion 84 on the other side (output side) of the gear holding portion 84. The output holding portion 85 is formed in a cylindrical shape having a diameter smaller than that of the gear holding portion 84, and the output shaft 87 is fixed inside the output holding portion 85 in the radial direction.

The output shaft 87 is formed in a shaft shape, is held by the carrier 83 in the present embodiment, and rotates together with the carrier 83. The output shaft 87 has knurled teeth on the outer periphery of the end on the output side. These teeth form an output gear at the end of the output shaft 87.

<Operation of actuator 1>
An example of the operation of the actuator 1 will be described below. First, when the motor 2 shown in FIGS. 1 and 2 is operated, the rotating shaft 22 rotates in the first direction or the second direction. Hereinafter, a case where the rotation shaft 22 rotates in the first direction will be described.

In the following description, the first direction regarding the rotation direction of each member is clockwise when each member is viewed from the other side (right side in FIG. 1) in the axial direction (direction parallel to X and the X axis). Means the direction of. On the other hand, in the following description, the second direction regarding the rotation direction of each member means a direction opposite to the clockwise direction when each member is viewed from the other side in the axial direction (right side in FIG. 1).

When the rotating shaft 22 rotates in the first direction, the sun gear 71 rotates in the first direction as the rotating shaft 22 rotates. As the sun gear 71 rotates, each of the three planetary gears 72 meshing with the sun gear 71 rotates (rotates) in the second direction around its own central axis (planetary axis 86). Further, the planetary gear 72 rotates (revolves) in the first direction around the rotation center axis of the sun gear 71 based on the rotation of the planetary gear 72 and the meshing of the planetary gear 72 and the first internal gear 46. To do. With the rotation (revolution) of the planetary gear 72, the carrier 73 rotates in the first direction about its own central axis (the central axis corresponding to the central axis of the sun gear 71).

In this way, when the carrier 73 rotates in the first direction, the sun gear 81 fixed to the carrier 73 rotates in the first direction. As the sun gear 81 rotates in the first direction, the three planetary gears 82 that mesh with the sun gear 81 rotate (rotate) in the second direction, respectively. Further, since the planetary gear 82 meshes with the second internal gear portion 56, it rotates (rotates) in the second direction, and due to this rotation, the planetary gear 82 moves around the central axis of the second planetary gear mechanism 8. Rotate (revolve) in the first direction. As the planetary gear 82 rotates (revolves) in the first direction, the carrier 83 rotates (rotates) in the first direction about its own central axis. Then, the rotation of the carrier 83 is transmitted to the output shaft 87 held by the carrier 83.

As an example of the operation of the actuator 1, the case where the rotating shaft 22 is rotated in the first direction has been described, but when the rotating shaft 22 is rotated in the second direction, the rotation directions of the gears are only opposite to each other. Similarly, the operation of the actuator 1 can be described.

<Action / effect>
According to the present embodiment, in the planetary gear device 3 that transmits the drive of the motor 2, the housing 4 that houses the planetary gear mechanism 6, particularly the planetary gear 72 of the first planetary gear mechanism 7, is the first housing element 40. Has.

In the first housing element 40, the first cylindrical body 44 surrounding the first planetary gear mechanism 7 and the first internal gear 46 that meshes with the planetary gear 72 are arranged apart from each other in the radial direction by the gap 48, and are connected. 49, connected by an open end face portion 40a. As a result, the vibration from the first internal gear 46 side to the first cylindrical body 44 is not transmitted through the gap portion 48, but is mainly transmitted through the connecting portion 49.

Therefore, the vibration of the first cylindrical body 44 transmitted from the first planetary gear mechanism 7, that is, the vibration of the housing 4 (specifically, the first housing element 40) is suppressed.

In this way, it is possible to suppress the noise generated from the planetary gear device 3 due to the vibration caused by the first planetary gear mechanism 7. Further, in the first housing element 40, the first internal gear 46 and the first cylindrical body 44 surrounding the first internal gear 46 are separated in the radial direction by the gap portion 48, and the connecting portion 49 (in the present embodiment). It is integrally connected at a portion (a portion provided between the gaps 48). Therefore, unlike the conventional case, it is not necessary to use the internal gear and the housing main body portion surrounding the internal gear separately.

Therefore, it is possible to reduce the number of parts, facilitate the assembly work, and reduce the assembly cost while suppressing the generation of noise and vibration during use.

The synthetic resin forming the first housing element 40 integrally including the first cylindrical body 44 and the first internal gear 46 and the housing 4 of the present embodiment includes real relate (PAR), polyacetal (POM), and polyamide (). PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethersulfone (PES), polyetheretherketone (PEEK) and the like can be mentioned. The synthetic resin forming the first housing element 40 including the first internal gear 46 and the first cylindrical body 44 may be made of the same material or different materials. It can be appropriately selected within the range in which the effect of the present invention is exhibited. Regarding the synthetic resin material (material) forming the first cylindrical body 44 and the first internal gear 46, the synthetic resin material having the same main component is used, and the density of the synthetic resin is changed to change the density of the synthetic resin to form the first cylindrical body. It is desirable that the synthetic resin forming 44 is harder.

(Modification example of housing)
The present invention is not limited to the above-described embodiment, and various modifications and applications are possible. In the above embodiment, in the first housing element 40 of the housing 4, the connecting portion 49 is connected between the first internal gear 46 and the first cylindrical body 44 to the outer periphery of the first internal gear 46 via the gap portion 48. A plurality of them are provided along the line, and the first internal gear 46 and the first cylindrical body 44 are integrally connected. However, the present invention is not limited to this, and due to the housing having a gap portion, the internal gear provided on the inner peripheral side must be connected to the cylindrical body surrounding the internal gear on the outer peripheral side over the entire circumference. It may be configured in any way.

Hereinafter, modifications of the housing 4 used in the planetary gear device 3 and the actuator 1 described above will be described with reference to FIGS. 5 to 9. The housings 4A to 4E of the modified examples 1 to 5 shown in FIGS. 5 to 9 have a configuration of the first housing element 40, specifically, a configuration of the gap portion 48 and the connection portion 49, as compared with the housing 4. Is different, and the other configurations are similar. Therefore, in the description of each modification, a configuration different from that of the housing 4 will be described, and similar components will be designated by the same names and reference numerals, and the description thereof will be omitted.

<Modification example 1>
FIG. 5 is a diagram provided for explaining a modification 1 of a housing of a planetary gear device according to an embodiment of the present invention. FIG. 5A is a front view of a modified example 1 of a housing of a planetary gear device according to an embodiment of the present invention, and FIG. 5B is a cross-sectional view taken along the line DEF of FIG. 4A.

The housing 4A shown in FIG. 5 is opened on one side (−X direction side), and the first housing element 40A is continuously provided on the second housing element 50 at the opening end surface portion 40a on the other side (X direction side). Has. A planetary gear mechanism 6 is housed inside the first housing element 40A and the second housing element 50.

The first housing element 40A in the housing 4A has a first cylindrical body (main body portion) 44A, a first internal gear 46A, a gap portion 48A, and a connecting portion 49A.

The first housing element 40A is different from the first housing element 40 in the shape of the gap portion 48A, that is, the shape of the connecting portion 49A.

The gap portion 48A is provided in the first housing element 40A between the first internal gear 46A and the first cylindrical body 44A so as to extend in the axial direction of the housing 4A.

A plurality of connecting portions 49A are arranged between the gap portions 48A, and the connecting portion 49A integrally continues the first cylindrical body 44A and the first internal gear 46A that are radially separated by the gap portion 48 in the radial direction. There is. The connecting portions 49A are formed at equal intervals in the circumferential direction. The connecting portion 49A partitions the gap portion 48A, and integrates the first cylindrical portion 44A and the first internal gear 46A.

The connecting portion 49A is provided so as to extend along the axial direction of the housing 4A, and is formed so that the width in the circumferential direction decreases from the first internal gear 46A side toward the first cylindrical body 44A side.

For example, as shown in FIG. 5A, the connecting portion 49A has a chevron-shaped triangular (inverted V-shaped) cross section so as to project outward in the radial direction.

The connecting portion 49A has a configuration in which it is linearly connected to the first cylindrical body 44A. As a result, the cross section of the connecting portion between the connecting portion 49A and the first cylindrical body 44A that is orthogonal to the radial direction becomes smaller than the area of the connecting portion between the connecting portion 49A and the first internal gear 46A.

As a result, the portion capable of transmitting the vibration by the connecting portion 49A becomes smaller, so that the vibration transmitted from the first internal gear 46A side to the first cylindrical body 44A can be further suppressed.

<Modification 2>
FIG. 6 is a diagram provided for explaining a modification 1 of a housing of a planetary gear device according to an embodiment of the present invention. FIG. 6A is a front view of a modified example 2 of a housing of a planetary gear device according to an embodiment of the present invention, and FIG. 6B is a sectional view taken along line GHJ of FIG. 6A. The housing 4B shown in FIG. 6 is opened on one side (−X direction side), and the first housing element 40B is continuously provided on the second housing element 50 at the opening end surface portion 40a on the other side (X direction side). Has. A planetary gear mechanism 6 is housed inside the first housing element 40B and the second housing element 50.

The first housing element 40B in the housing 4B has a first cylindrical body (main body portion) 44B, a first internal gear 46B, a gap portion 48B, and a connecting portion 49B.

The connecting portion 49B connects the first cylindrical body 44B and the first internal gear 46B at two positions sandwiching the central axis of the housing 4B between the first cylindrical body 44B and the first internal gear 46B, and connects the housing. It extends along the axial direction of 4B. The connecting portion 49B partitions the gap portion 48B, and integrates the first cylindrical portion 44B and the first internal gear 46B.

As a result, the same effect as that of the embodiment can be obtained, and the cross-sectional area of the connecting portion 49B as a vibration transmission path between the first cylindrical body 44B and the first internal gear 46B is reduced to reduce the first The vibration transmitted from the internal gear 46B side to the first cylindrical body 44B can be suppressed.

<Modification example 3>
FIG. 7 is a diagram provided for explaining a modification 1 of a housing of a planetary gear device according to an embodiment of the present invention. FIG. 7A is a front view of a modified example 3 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 7B is a sectional view taken along line KK of FIG. 7A.

The housing 4C shown in FIG. 7 is opened on one side (−X direction side), and the first housing element 40C is continuously provided on the second housing element 50 at the opening end surface portion 40a on the other side (X direction side). Has. A planetary gear mechanism 6 is housed inside the first housing element 40C and the second housing element 50.

The housing 4C has a first cylindrical body (main body portion) 44C, a first internal gear 46C, a gap portion 48C, and an open end face portion (connection portion) 40a.

In the first housing element 40C in the housing 4C, the gap portion 48C is provided between the first cylindrical body 44C and the first internal gear 46C so as to surround the entire circumference of the first internal gear 46C.

The first cylindrical body (main body portion) 44C and the first internal gear 46C are connected by an opening end face portion 40a on the other side (output side). The opening end face portion 40a is an end portion on one end side in the axial direction, and connects the first cylindrical body and the first internal gear 46C so as to partition the gap portion 48C in the axial direction. In the housing 4C, the opening end face portion 40a functions as a connecting portion, and is integrally formed with one end portion of the second housing element 50 via the opening end face portion 40a. The open end face portion 40a partitions the gap portion 48C, and integrates the first cylindrical portion 44C and the first internal gear 46C.

As a result, vibration is not transmitted from the outer peripheral surface of the first internal gear 46C to the first cylindrical body 44C, but is transmitted from only the open end surface portion 40a to the first cylindrical body 44C. The vibration transmitted to the cylindrical body 44C can be suppressed.

<Modification example 4>
FIG. 8 is a diagram provided for explaining a modification 1 of a housing of a planetary gear device according to an embodiment of the present invention. FIG. 8A is a front view of a modified example 4 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 8B is a sectional view taken along line LL of FIG. 8A.

The first housing element 40D in the housing 4D shown in FIG. 8 has a first cylindrical body (main body portion) 44D, a first internal gear 46D, a gap portion 48D, and a connecting portion 49D.

The connecting portion 49D connects the first cylindrical body 44D and the first internal gear 46D between the first cylindrical body 44D and the first internal gear 46D, and is provided so as to extend along the axial direction of the housing 4D. Has been done. The connecting portion 49D has a bent portion 491 that bends in the circumferential direction. The bent portion 491 is elastically deformable.

The connecting portions 49D are provided at equal intervals on the entire circumference of the first internal gear 46D. The connecting portion 49D partitions the gap portion 48D, and integrates the first cylindrical portion 44D and the first internal gear 46D.

As a result, the first internal gear 46D is in a state of being displaceably supported in the radial direction and the axial direction with respect to the first cylindrical body 44D, and the same effect as that of the embodiment can be obtained, and the bent portion 491 can be obtained. The vibration transmitted from the first internal gear 46D can be absorbed, and the vibration transmitted from the first internal gear 46D side to the first cylindrical body 44D can be suppressed.

<Modification 5>
FIG. 9 is a diagram provided for explaining a modification 1 of a housing of a planetary gear device according to an embodiment of the present invention. 9A is a front view of a modified example 5 of the housing of the planetary gear device according to the embodiment of the present invention, and FIG. 9B is a cross-sectional view taken along the line MM of FIG. 9A.

The first housing element 40E in the housing 4E shown in FIG. 9 has a first cylindrical body (main body portion) 44E, a first internal gear 46E, a gap portion 48E, and a connecting portion 49E.

The connecting portion 49E is formed so as to be inclined with respect to the axial direction as compared with the connecting portion 49 of the embodiment. The inclination of the connecting portion 49E is provided corresponding to the inclination of the helical gear. The connecting portion 49E connects the first cylindrical body 44E and the first internal gear 46E between the first cylindrical body 44E and the first internal gear 46E, and shafts while being inclined with respect to the axial direction of the housing 4E. It is provided extending in the direction. Further, the connecting portion 49E partitions the gap portion 48E, and integrates the first cylindrical portion 44E and the first internal gear 46E.

The connecting portions 49E are provided at equal intervals over the entire circumference of the internal gear 46E. As a result, the vibration transmitted from the first internal gear 46E side to the first cylindrical body 44E can be suppressed.

In each of the first internal gears 46, 46A to 46E of the housing of the embodiment and the modified example, the end portion on the other side in the axial direction, which is connected to the open end face portion 40a, is the open end face portion 40a. It may be formed so that the wall thickness becomes thinner. In this configuration, the first internal gears 46, 46A to 46E are joined to the open end face portion 40a at a portion thinner than the portion where the internal tooth portions 46a are formed in the first internal gears 46, 46A to 46E. As a result, the vibrations from the first internal gears 46, 46A to 46E are connected to the other side (X direction side) in the axial direction (in the present embodiment, the second housing element 50 via the open end face portion 40a). The vibration transmitted from the internal planetary gear mechanism 6 can be further suppressed in the housings 4, 4A to 4E as a whole.

Further, the actuator 1 has a two-stage planetary gear mechanism of a first planetary gear mechanism 7 and a second planetary gear mechanism 8 as a speed reducer for decelerating the rotation of the motor 2, but the number of stages is arbitrary. Can be set. For example, the planetary gear mechanism may be provided in three or more stages to further increase the reduction ratio, or the planetary gear mechanism in only one stage may be configured.

Further, in the above embodiment, the first planetary gear mechanism, which is a first-stage mechanism that rotates at high speed, has a configuration in which an internal gear is provided in the housing and a gap 48 is provided between the internal teeth and the outer surface of the housing. Although it was applied to 7, it may be applied to the second planetary gear mechanism 8, which is a second-stage mechanism that rotates at a low speed. As a result, vibration and noise can be further reduced.

Further, in the above embodiment, the case where the motor 2 is used as a speed reducer that reduces the rotation of the motor 2 and outputs the power from the output shaft 87 has been described, but the application is not limited. For example, the rotating shaft of the motor 2 may be connected with the portion provided with the output shaft 87 shown in FIG. 1 as the input side, and the output shaft may be connected with the portion provided with the sun gear 71 as the output side. As a result, it can be used as a speed increasing machine that speeds up the rotation of the motor and outputs it. Further, the configuration of the first housing element 40 can be applied to any configuration as long as a gear mechanism is provided inside the housing, such as an industrial machine such as a robot or a machine tool, or a playset such as a so-called coffee cup. it can. Further, the planetary gear device 3 having the first housing element 40 can also be similarly applied to various machines and devices such as automobiles, robots, industrial machines, playsets, etc. that use a speed reducer or a speed increaser.

Further, in using the present invention for various purposes, when a planetary gear mechanism having three or more stages is provided, the structure of the housing of the present embodiment is applied to the planetary gear mechanism operating at the highest speed, specifically, the first. It is preferable to apply the configuration of the housing element 40. Thereby, the generation of vibration and noise can be effectively reduced.

Further, in the above embodiment, the gears used for transmitting the power of the motor 2 to the output shaft 87 have been described as helical gears, but other gears such as spur gears may be used. ..

Further, although the case where the housing 4 is used as a part of the planetary gear device has been described, its use is not limited and may be used as a part of another gear mechanism.

The embodiments of the present invention have been described above. The above description is an example of a preferred embodiment of the present invention, and the scope of the present invention is not limited thereto. That is, the description of the configuration of the device and the shape of each part is an example, and it is clear that various changes and additions to these examples are possible within the scope of the present invention.

The planetary gear device and actuator according to the present invention can be incorporated into various mechanical devices.

1 Actuator 2 Motor 3 Planetary gear device 4, 4A, 4B, 4C, 4D, 4E Housing 6 Planetary gear mechanism 7 1st planetary gear mechanism 8 2nd planetary gear mechanism 21 Motor body 22 Rotating shaft 31a Opening 31 Connection lid 40, 40A, 40B, 40C, 40D, 40E 1st housing element 40a Open end face 42 Engagement 44, 44A, 44B, 44C, 44D, 44E 1st cylinder (main body)
44a Outer peripheral surface 46, 46A, 46B, 46C, 46D, 46E 1st internal gear (internal gear part)
48, 48A, 48B, 48C, 48D, 48E Air gap 49, 49A, 49B, 49D, 49E Connection 50 Second housing element 54 Second cylinder 56 Second internal gear 56a, 72a Tooth 57 Opening closure 57a Cylinders 71, 81, Sun gears 71a, 81a Sun teeth 72, 82 Planetary gears 72a, 82a Planetary teeth 73, 83 Carriers 73a, 84a Storage openings 76, 86 Planetary shafts 84 Gear holders 85 Output holders 87 Output shafts 491 Bent part

Claims (9)

A housing that is formed in a tubular shape and has an internal gear portion that meshes with a gear of a gear mechanism housed inside and forms a part of the gear mechanism on the inner peripheral surface.
With the internal gear
It has a tubular main body portion provided so as to surround the outer circumference of the internal gear portion, and has a tubular main body portion.
A gap portion extending in the axial direction of the housing is provided between the internal gear portion and the main body portion.
The internal gear portion and the main body portion are integrally provided by a connecting portion that partitions the gap portion.
housing. A plurality of the gap portions are provided in the circumferential direction between the internal gear portion and the main body portion.
The connection portion is provided between the plurality of gap portions.
The housing according to claim 1. A plurality of the gap portion and the connection portion are provided at equal intervals in the circumferential direction.
The housing according to claim 2. The connecting portion is provided so as to extend along the axial direction, and is formed so that the width in the circumferential direction decreases from the internal gear portion side to the main body portion side.
The housing according to any one of claims 1 to 3. The connecting portion extends along the axial direction and is provided so as to be bent in the circumferential direction between the main body portion and the internal gear portion, and has a bent portion that can be elastically deformed.
The housing according to any one of claims 1 to 3. The connecting portion extends along the axial direction and is provided so as to be inclined in the circumferential direction.
The housing according to any one of claims 1 to 3. The gap portion is provided on the inner peripheral side of the main body portion so as to surround the outer circumference of the internal gear portion.
The connecting portion is an end portion on one end side in the axial direction, and connects the main body portion and the internal gear portion so as to partition the gap portion in the axial direction.
The housing according to claim 1. The housing according to any one of claims 1 to 7.
A planetary gear mechanism housed in the housing and having a planetary gear that meshes with the internal gear portion as the gear.
Have,
Planetary gear device. With an electric motor
A speed reducer for decelerating the rotation of the electric motor is provided.
The speed reducer is the planetary gear device according to claim 8.
The sun gear provided in the planetary gear device is connected to the output shaft of the electric motor.
Actuator.

Images