Planetary gear device and resin molded body

Abstract

This invention provides a highly convenient planetary gear device and a resin molded body. The planetary gear device includes: a sun gear; an internal gear, which surrounds the outer periphery of the sun gear and is configured to be coaxial with the sun gear; a planetary gear having a protruding planetary shaft portion, which meshes with the sun gear and the internal gear, and rotates around the sun gear while revolving around the planetary shaft portion; and a bracket having a bearing portion that accommodates the planetary shaft portion in a manner that allows the planetary shaft portion to rotate, and outputs rotational motion by means of a pressing force transmitted from the planetary shaft portion through the bearing portion during the rotation of the planetary gear, rotating around the bracket axis, wherein the planetary shaft portion can be displaced in the bearing portion.

Description

Technical Field

[0001] This invention relates to planetary gear assemblies and resin molded bodies. Background Technology

[0002] Planetary gear units, as speed reducers that reduce the input rotational speed to output speed, are used in various mechanical devices such as automobiles and robots.

[0003] In a planetary gear system, the sun gear is connected to the rotating shaft of a drive source such as a motor. Between the sun gear and an internal gear arranged around its outer periphery and aligned with the same axis, planetary gears mesh with both. Supported by a carrier, the planetary gears rotate (also called "rotation") around their planetary shafts and revolve around the sun gear (also called "revolution"). The rotational speed of the planetary gears (revolutions per unit time) is a speed reduced at a predetermined ratio (reduction ratio) relative to the rotational speed input from the drive source to the sun gear. The carrier rotates around its axis as the planetary gears revolve. An output shaft is connected to the carrier at its axis, and the rotational motion of the carrier is output to the outside via this output shaft.

[0004] For example, in the conventional planetary gear device described in Patent Document 1, the opening of the bearing portion accommodating the planetary shaft in the bracket supporting the planetary gear not only penetrates the main body of the bracket axially but also opens radially outward from the bracket. Therefore, the opening of the bearing portion has a generally C-shaped opening when viewed from above in the axial direction. The inner wall of the bearing portion opening contacts the outer peripheral surface of the mounted planetary shaft in a range exceeding 180° (in Patent Document 1, this range is formed by combining angles α and β, each exceeding 90°). In other words, the bearing portion holds the mounted planetary shaft in a manner that prevents it from shifting.

[0005] Existing technical documents Patent documents Patent Document 1: U.S. Patent No. 11353105. Summary of the Invention

[0006] The technical problem that the invention aims to solve Furthermore, as mentioned above, planetary gear units are used by connecting to external mechanical devices via their output shafts. Therefore, it is desirable for them to be robust and not easily affected by external influences during operation. In addition, from a manufacturing cost perspective, it is desirable for them to have a high degree of flexibility in adapting to various mechanical devices or installation environments. In other words, a highly convenient planetary gear unit is required.

[0007] The purpose of this invention is to provide a highly convenient planetary gear device and resin molded body.

[0008] Technical solutions for solving technical problems One technical solution of the planetary gear device of the present invention includes: Sun gear; An internal gear surrounds the outer periphery of the sun gear and is configured to be on the same axis as the sun gear; A planetary gear having a protruding planetary shaft portion that meshes with the sun gear and the internal gear, and rotates around the sun gear while revolving around the planetary shaft portion; and The bracket has a bearing portion that accommodates the planetary shaft portion in a manner that allows the planetary shaft portion to rotate. Rotational motion is output by means of a pressing force transmitted from the planetary shaft portion via the bearing portion within the orbit of the planetary gears, rotating about the bracket's axis. Within the bearing section, the planetary shaft section is capable of displacement.

[0009] One technical solution of the present invention is used as the bracket in the above-described planetary gear device.

[0010] Invention Effects According to the present invention, the convenience of planetary gear devices can be improved. Attached Figure Description

[0011] Figure 1 This is an exploded perspective view of an actuator of a planetary gear device having one embodiment of the present invention.

[0012] Figure 2 This is an exploded perspective view of the planetary gear device of this embodiment.

[0013] Figure 3 This is an exploded perspective view of the main part of the output-side planetary gear mechanism in the planetary gear device of this embodiment.

[0014] Figure 4 This is a diagram used to illustrate the relationship between the components of the output-side planetary gear mechanism.

[0015] Figure 5 This is a three-dimensional view of the front side of the output side bracket.

[0016] Figure 6 This is a three-dimensional view of the rear side of the output side bracket.

[0017] Figure 7 This diagram illustrates the effects of external factors on a planetary gear mechanism.

[0018] Figure 8 This is a diagram illustrating the structure of the bearing section of the output side bracket.

[0019] Figure 9 This is a diagram illustrating the details of the bearing section of the output side bracket.

[0020] Figure 10 This is a diagram used to illustrate the relationship between the output shaft connection of the output side bracket and the outer cylinder of the output side housing component.

[0021] Figure 11 This is a diagram showing the phenomenon of displacement occurring on the + side of the output axis in the Y direction.

[0022] Figure 12 It indicates accompaniment Figure 11 The diagram shows the phenomenon where the output shaft connection of the bracket has been displaced in the Y direction (+).

[0023] Figures 13A-13D It is used for explanation Figure 12 The diagram shows the rotational motion of the output-side planetary gear mechanism in the indicated state, where... Figure 13A This is a diagram showing the angular position of the movable part on the output side at the first time point. Figure 13B It is a graph showing the displacement of a specific planetary shaft within a specific bearing section at the first time point. Figure 13C This is a diagram showing the angular position of the movable part on the output side at the second time point. Figure 13D It is a graph showing the displacement of a specific planetary shaft within a specific bearing section at the second time point.

[0024] Figure 14 This is a diagram illustrating a modified example of the planetary gear assembly with respect to gear dimensions, namely Modified Example 1, of this embodiment.

[0025] Figure 15A , Figure 15B This is a diagram illustrating a modified example, namely Modified Example 2, of the planetary gear assembly regarding the opening shape of the bearing portion in this embodiment, wherein... Figure 15A This diagram shows the state in which the bearing section accommodates the planetary shaft section with a smaller diameter. Figure 15B This diagram shows the state in which the bearing section accommodates a planetary shaft section with a larger diameter.

[0026] Figure 16A , 16B This is a diagram illustrating another variation of the planetary gear assembly with respect to the opening shape of the bearing portion in this embodiment, namely variation 3, in which... Figure 16A This diagram shows the state in which the bearing section accommodates the planetary shaft section with a smaller diameter. Figure 16B This diagram shows the state in which the bearing section accommodates a planetary shaft section with a larger diameter.

[0027] Figure 17 This is a diagram of a planetary gear device, namely, Variation 4, which is used to illustrate another variation of the opening shape of the bearing portion in this embodiment.

[0028] Explanation of reference numerals in the attached figures 1 Actuator 2 Output shaft 10 motors 11 Motor body 12 Rotation axis 100 Planetary Gear Assembly 101 Input-side planetary gear mechanism 102 Output-side planetary gear mechanism 120 casing 121 Input-side housing component 1211 Input side internal gear 122 Output side housing component 1221 Output side internal gear 1222 outer cylinder 140 movable parts 141 Input-side movable part 1412, 1414 Input-side planetary gears 1415 Input side bracket 1416 Bearing Section 142 Output-side movable part 1421 Output-side sun gear 1422, 1423, 1424 Output-side planetary gears Planetary axis sections of 1422s, 1423s, and 1424s 1425 Output side bracket 1427 Output shaft connection part 1430 First annular plate-shaped part 1432, 1433, 1434 First Bearing Section 1440 Second annular plate-shaped part 1442, 1443, 1444 Second Bearing Section 1441 Through Hole 1450 radial columnar part CC Output Side Bracket Shaft G1, G2 interval O orbit R1 and R2 are the orbital radii (interaxial distances). SC output side sun gear shaft Widths W, W1, W2, W3, W4, W5, W6 Diameters of shafts D, D1, D2, D3, D4, and D5 L, L1, L2, L3, L4, L5 are lengths. Detailed Implementation

[0029] Hereinafter, a planetary gear device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] Figure 1 This is an exploded perspective view of the actuator of the planetary gear device having this embodiment. Figure 2 This is an exploded perspective view of the planetary gear device of this embodiment. Figure 3 This is an exploded perspective view of the main part of the output-side planetary gear mechanism in the planetary gear device of this embodiment. Figure 4 This is a diagram used to illustrate the relationship between the components of the output-side planetary gear mechanism. Figure 5 This is a three-dimensional view of the front side of the output side bracket. Figure 6 This is a three-dimensional view of the rear side of the output side bracket. Figure 7 This diagram illustrates the effects of external factors on a planetary gear mechanism. Figure 8 This is a diagram illustrating the structure of the bearing section of the output side bracket. Figure 9 This is a diagram illustrating the details of the bearing section of the output side bracket. Figure 10 This is a diagram used to illustrate the relationship between the output shaft connection of the output side bracket and the outer cylinder of the output side housing component.

[0031] In the following description, an orthogonal coordinate system (X, Y, Z) is used. The Z-direction is parallel to the axial direction of each component constituting the planetary gear unit 100. For ease of explanation, in the Z-direction, the + (positive) side is also called the front side or output side, and the - (negative) side is also called the rear side or input side. Furthermore, the X-direction is also called the left-right direction, and the Y-direction is also called the up-down direction. Additionally, the direction extending radially from the axis of each component is called the radial direction; the side radially closer to the axis of each component is called the inner side, and the side radially farther from the axis of each component is called the outer side. Furthermore, the direction extending in a ring around the axis of each component is called the circumferential direction. It should be noted that when referring to terms such as axial direction, axis, radial direction, and circumferential direction for a specific component, the name of the component is combined with the term. For example, when referring to the axial direction, axis, radial direction, and circumferential direction of the bracket, it is called "bracket axial direction," "bracket axis," "bracket radial direction," and "bracket circumferential direction." When referring to the direction of rotation of each component, it is combined with the name of the component to refer to the direction of rotation (e.g., "bracket rotation direction"). In the following text, clockwise rotation refers to rotation that is clockwise (right-handed) when viewed from the Z-direction + side, and counterclockwise rotation refers to rotation that is counterclockwise (left-handed) when viewed from the Z-direction + side.

[0032] In this embodiment, the actuator 1 includes a motor 10 as an example of a drive source and a planetary gear assembly 100. The actuator 1 is used, for example, as an electric rear door actuator for opening and closing a car's rear door. However, the application of the actuator 1 is not limited to this. The motor 10 includes a motor body 11 and a rotating shaft 12. The motor 10 operates under the control of a control unit (not shown), causing the rotating shaft 12 to rotate and drive the planetary gear assembly 100. There is no particular limitation on the type of motor 10; it can be any conventionally known electric motor.

[0033] The planetary gear unit 100 reduces the rotation input from the motor 10 by a predetermined reduction ratio and outputs it to the outside. The planetary gear unit 100 includes a housing 120 and a movable part 140 housed within the housing 120. The housing 120 includes an input-side housing member 121 and an output-side housing member 122. The movable part 140 includes an input-side movable part 141 and an output-side movable part 142. The input-side movable part 141, together with the internal gear (input-side internal gear) 1211 of the input-side housing member 121, constitutes an input-side planetary gear mechanism 101. The output-side movable part 142, together with the internal gear (output-side internal gear) 1221 of the output-side housing member 122, constitutes an output-side planetary gear mechanism 102.

[0034] The various components of the planetary gear unit 100 can be resin molded bodies made by processing resin material through methods such as injection molding. Alternatively, some components can be made of resin, while others can be made of metal. However, for structurally complex components such as the input-side bracket 1415 or the output-side bracket 1425, described later, it is advantageous to use resin material for integral molding, which can significantly reduce the manufacturing cost of the planetary gear unit 100.

[0035] The input-side movable part 141 and the output-side movable part 142 are arranged relative to each other along the Z-direction on the input and output sides, and are housed inside the housing 120 formed by the input-side housing member 121 and the output-side housing member 122. The input-side planetary gear mechanism 101 reduces the rotation input from the motor 10 by a predetermined reduction ratio and outputs it to the subsequent output-side planetary gear mechanism 102. The output-side planetary gear mechanism 102 reduces the rotation input from the preceding input-side planetary gear mechanism 101 by a predetermined reduction ratio and outputs it to the outside.

[0036] It should be noted that, in this embodiment, the planetary gear device 100 has a structure including a two-stage planetary gear mechanism (input-side planetary gear mechanism 101 and output-side planetary gear mechanism 102), but the number of stages of the planetary gear mechanism is not limited to two. The number of stages of the planetary gear mechanism can be only one stage, or it can be three or more stages.

[0037] The input-side movable part 141 includes an input-side sun gear (not shown), three input-side planetary gears 1412 and 1414 (one of which is not shown), and an input-side bracket 1415. The input-side sun gear is connected to the rotating shaft 12 of the motor 10 and rotates coaxially with the rotating shaft 12. That is, the input-side sun gear is directly driven to rotate by the motor 10. The sun teeth formed on the outer circumferential surface of the input-side sun gear have, for example, helical teeth obliquely cut relative to the axial direction of the input-side sun gear, i.e., a so-called helical gear. The three input-side planetary gears 1412 and 1414 are arranged at approximately equal intervals in the circumferential direction of the input-side sun gear. The three input-side planetary gears 1412 and 1414 mesh with both the input-side sun gear and the input-side internal gear 1211, which is arranged on the same axis relative to the input-side sun gear. The teeth formed on the outer circumferential surfaces of the three input-side planetary gears 1412 and 1414, and the teeth formed on the inner circumferential surface of the input-side internal gear 1211, all have helical teeth obliquely cut relative to their respective axial directions; that is, they are so-called helical gears. Each of the three input-side planetary gears 1412 and 1414 is supported in a rotatable manner by a bearing portion 1416 formed in the input-side bracket 1415. Based on the rotation of the input-side sun gear, the three input-side planetary gears 1412 and 1414 rotate around their own axes (planetary shafts) while simultaneously revolving around the input-side sun gear. The input-side bracket 1415 rotates around its own axis based on the revolution of the three input-side planetary gears 1412 and 1414. The input-side bracket 1415 outputs rotational motion to the sun gear (output-side sun gear) 1421 of the output-side movable portion 142 connected to its output-side end.

[0038] Furthermore, in this embodiment, the opening shape of the bearing portion 1416 formed on the input-side bracket 1415 is the same as the opening shape of the bearing portions (first bearing portions 1432, 1433, 1434, and second bearing portions 1442, 1443, 1444) formed on the output-side bracket 1425, which will be described later. Details regarding the opening shape of the bearing portions will be described later. It should be noted that various conventionally known structures can be used as the structure of the input-side planetary gear mechanism 101, including the input-side bracket 1415.

[0039] The output-side movable part 142 includes an output-side sun gear 1421, three output-side planetary gears 1422, 1423, and 1424, and an output-side bracket 1425. As described above, the output-side sun gear 1421 is connected to the output-side end of the input-side bracket 1415 and rotates coaxially with the input-side bracket 1415. That is, the output-side sun gear 1421 is driven to rotate by the input-side bracket 1415, but it can also be considered as being indirectly driven to rotate by the motor 10. As a variation, the output-side sun gear 1421 may be directly connected to the rotating shaft 12 of the motor 10, in which case the output-side sun gear 1421 is directly driven to rotate by the motor 10.

[0040] The sun teeth formed on the outer circumferential surface of the output-side sun gear 1421, for example, have helical teeth that are obliquely cut relative to the axial direction of the output-side sun gear 1421, i.e., they are so-called helical gears. The teeth formed on the outer circumferential surfaces of the three output-side planetary gears 1422, 1423, and 1424, and the teeth formed on the inner circumferential surface of the output-side internal gear 1221, for example, all have helical teeth that are obliquely cut relative to their respective axial directions, i.e., they are so-called helical gears.

[0041] Three output-side planetary gears 1422, 1423, and 1424 are arranged at approximately equal intervals around the output-side sun gear. These three output-side planetary gears 1422, 1423, and 1424 mesh with both the output-side sun gear 1421 and the output-side internal gear 1221, which is arranged on the same axis relative to the output-side sun gear 1421 (see [link]). Figure 4 ).

[0042] in addition, Figure 4 The diagram schematically illustrates the meshing of the teeth. Figure 4 In the diagram, circle 1421b represents the root of the output-side sun gear 1421, and circle 1421t represents the tip of the output-side sun gear 1421. Similarly, circle 1422b represents the root of the output-side planetary gear 1422, and circle 1422t represents the tip of the output-side planetary gear 1422. Likewise, circles 1423b and 1424b represent the roots of the output-side planetary gears 1423 and 1424, and circles 1423t and 1424t represent the tips of the output-side planetary gears 1423 and 1424. Figure 4 As shown, the interaxial distance between the output-side sun gear 1421 and the output-side planetary gears 1422, 1423, 1424, which are meshed together with the output-side internal gear 1221, is called the radius (orbit radius) R1 of the orbital O of the output-side planetary gears 1422, 1423, 1424. Furthermore, as... Figure 4As shown, a gap G1 is left between the outer periphery of the first annular plate portion 1430 and the second annular plate portion 1440 of the output side bracket 1425 and the inner periphery (circle 1221t) of the output side internal gear 1221.

[0043] The output-side planetary gear 1422 is supported in a rotatable manner by rotatably accommodating the planetary shaft portion 1422 in the first bearing portion 1430 and the second bearing portion 1442 formed in the second annular plate portion 1430 and the second annular plate portion 1440. The output-side planetary gear 1423 is supported in a rotatable manner by rotatably accommodating the planetary shaft portion 1423 in the first bearing portion 1430 and the second bearing portion 1443 formed in the second annular plate portion 1430 and the second annular plate portion 1440. The output-side planetary gear 1424 is supported in a rotatable manner by rotatably accommodating the planetary shaft portion 1424 in the first bearing portion 1430 and the second bearing portion 1444 formed in the second annular plate portion 1440.

[0044] The output-side planetary gears 1422, 1423, and 1424 rotate around their own axes (i.e., the planetary shaft portions 1422s, 1423s, and 1424s protruding from their own axes) and revolve around the output-side sun gear 1421 based on the rotation of the output-side sun gear 1421. The output-side bracket 1425 rotates around its own axis based on the revolution of the planetary gears 1422, 1423, and 1424. The output-side bracket 1425 outputs rotational motion to the outside via the output shaft 2 connected to the output shaft connector 1427 disposed at its output-side end. In this embodiment, the output shaft connector 1427 is a cylindrical portion with knurled teeth on its inner circumferential surface, and an output shaft 2 with corresponding teeth on its outer circumferential surface at its rear end is inserted into the output shaft connector 1427. The output shaft connector 1427 is an example of a rotational motion output portion.

[0045] The output-side bracket 1425 has a first annular plate portion 1430 and a second annular plate portion 1440, each a ring-shaped plate, spaced apart in the Z direction. The first annular plate portion 1430 and the second annular plate portion 1440 are connected in parallel to each other by a radial columnar portion 1450, which extends radially in the XY plane and columnarly in the Z direction. A through hole 1441 for the output-side sun gear 1421 to pass through is provided on the second annular plate portion 1440, and an output shaft connecting portion 1427 is provided on the output-side end face of the first annular plate portion 1430. When each output-side planetary gear 1422, 1423, 1424 is mounted on the output-side bracket 1425, the first annular plate portion 1430 and the second annular plate portion 1440 are respectively arranged on both sides of each output-side planetary gear 1422, 1423, 1424 in the Z direction.

[0046] Bearing portions, with an equal number to the number of output-side planetary gears 1422, 1423, and 1424, are provided on the first annular plate portion 1430 and the second annular plate portion 1440, and these bearing portions are located at approximately equal angular intervals. The bearing portions provided on the first annular plate portion 1430 are first bearing portions 1432, 1433, and 1434. The bearing portions provided on the second annular plate portion 1440 are second bearing portions 1442, 1443, and 1444. The first bearing portions 1432, 1433, and 1434 and the second bearing portions 1442, 1443, and 1444, located at the same angular positions, have the same opening shape. Specifically, in this embodiment, the openings of the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444 not only extend axially through the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444, but also open radially outwards from the output side bracket (hereinafter referred to as "bracket radial"). Therefore, these openings have a generally C-shaped opening when viewed from an axial perspective. Thus, the output side planetary gears 1422, 1423, 1424 can be easily installed from the radially outwards from the bracket, and can also be easily disassembled.

[0047] Furthermore, planetary gear units are typically connected to the outside via output shaft 2, thus presenting a technical problem of being susceptible to external influences through output shaft 2 (see [link to relevant documentation]). Figure 7 In particular, if an external force in the vertical or horizontal direction is applied to the output shaft 2 while the planetary gear unit 100 is operating, causing a shaft offset (displacement of the shaft center) of the output shaft 2, and this shaft offset is transmitted to the planetary gear unit 100, abnormal noise is likely to be generated in the planetary gear unit 100.

[0048] In this embodiment, the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444 are configured in such a way that the planetary shaft portions 1422s, 1423s, 1424s can be displaced. As a result, even if the output shaft 2 is offset during operation, the generation of abnormal noise can be suppressed.

[0049] Specifically, such as Figure 8 , 9 As shown, the openings of the first bearing portion 1432 and the second bearing portion 1442 have an extended shape extending radially along the bracket. This shape allows the planetary shaft portion 1422s to be displaced radially within the first bearing portion 1432 and the second bearing portion 1442. In this embodiment, the first bearing portion 1432 and the second bearing portion 1442 have a continuous wide shape, meaning that they continuously have a width W greater than or equal to the diameter of the planetary shaft portion 1422s along almost the entire radial length of their bracket. Therefore, the first bearing portion 1432 and the second bearing portion 1442 can ensure a range of motion for the planetary shaft portion 1422s along almost the entire radial length of their bracket. Furthermore, while ensuring a large range of motion for the planetary shaft portion 1422s to allow it to displace within a large range is preferable, the ensured range of motion does not necessarily have to be very large. The extended shapes of the openings of the first bearing portion 1432 and the second bearing portion 1442 can be designed according to the tolerance of shaft misalignment. Furthermore, in the conventional bearing portions described above, the bearing portion contacts more than half a circumference of the outer periphery of the mounted planetary shaft portion to hold the planetary gear, thus preventing any displacement of the planetary shaft portion. However, if there is clearance due to manufacturing tolerances between the bearing portion and the planetary gear, a small displacement of the planetary shaft portion within the bearing portion is permissible. However, such a small displacement cannot suppress abnormal noise caused by shaft misalignment. In this embodiment, in order to suppress abnormal noise caused by shaft misalignment, the openings of the first bearing portion 1432 and the second bearing portion 1442 are formed into a continuous wide shape with a length L that significantly exceeds the clearance caused by manufacturing tolerances.

[0050] Furthermore, the aforementioned extended shape is only required to have a width W and a length L that allow the planetary shaft portion 1422s to move radially in the bracket. Therefore, it does not necessarily have to be a straight strip shape as in this embodiment, nor does it need to be an oblong or elliptical shape. Even a perfect circle shape can have a width W and a length L that allow the planetary shaft portion 1422s to move radially in the bracket.

[0051] Furthermore, the radial displacement of the planetary shaft 1422s along this direction does not necessarily refer to the radial displacement of the output side bracket axis CC in a strict sense. Even a displacement that moves obliquely relative to the aforementioned strict radial displacement of the bracket can be considered a radial displacement of the bracket as long as it changes the distance between the bracket and the output side bracket axis CC.

[0052] When the planetary shaft 1422s is in operation, it rotates and moves clockwise in this embodiment while meshing with the output-side sun gear 1421 and the output-side internal gear 1221. At this time, the planetary shaft 1422s abuts against the inner walls of the first bearing portion 1432 and the second bearing portion 1442, applying pressure to these inner walls. By means of the pressure transmitted from the planetary shaft 1422s via the first bearing portion 1432 and the second bearing portion 1442 in the manner described above, the output-side bracket 1425 rotates around the output-side bracket axis CC and outputs this rotational motion. Figure 9 As shown, the planetary shaft portion 1422s can be displaced within the first bearing portion 1432 and the second bearing portion 1442 within a range up to the length L. Therefore, the contact position of the planetary shaft portion 1422s, i.e. the position where the pressure is transmitted to the first bearing portion 1432 and the second bearing portion 1442, can also be displaced within a range up to the length L.

[0053] Here, the preferred option is, Figure 8 The distance G1 shown is greater than the distance G2 between the outer periphery of the output shaft connection portion 1427 (which is left as a gap) and the outer cylindrical portion 1222 (an example of a cylindrical portion) surrounding the output shaft connection portion 1427 (see [reference]). Figure 10 If the interval G1 is smaller than the interval G2, the first annular plate-shaped portion 1430 of the output side bracket 1425 is more likely to collide with the inner circumference of the output side internal gear 1221. In other words, by making the interval G1 larger than the interval G2, the possibility of the first annular plate-shaped portion 1430 colliding with the inner circumference of the output side internal gear 1221 can be reduced.

[0054] If the interval G1 is greater than the interval G2, the output shaft connecting portion 1427 will abut against the inner circumference of the outer cylinder portion 1222 before the first annular plate portion 1430 abuts against the inner circumference of the output-side internal gear 1221. Preferably, there is still a clearance area remaining at this time, allowing the planetary shaft portion 1422s to be displaced further radially inward of the bracket than the position of the planetary shaft portion 1422s in the first bearing portion 1432 and the second bearing portion 1442. If the first bearing portion 1432 and the second bearing portion 1442 have an extended shape that includes this clearance area, even if the output-side bracket 1425 experiences a large shaft offset, the first bearing portion 1432 and the second bearing portion 1442 will not push the planetary shaft portion 1422s from the inside to the outside. Therefore, the output-side planetary gear 1422 will not be pressed against the output-side internal gear 1221 and stop working.

[0055] Reference Figure 8 , 9 The description only mentions the planetary shaft portion 1422s of the output-side planetary gear 1422 and the first bearing portion 1432 and second bearing portion 1442 that house it. However, the output-side planetary gears 1423 and 1424 have the same shape and size as the output-side planetary gear 1422, and the first bearing portion 1433, the second bearing portion 1443, the first bearing portion 1434, and the second bearing portion 1444 also have the same shape and size as the first bearing portion 1432 and the second bearing portion 1442. Therefore, referring to... Figure 8 , 9 The description also applies to the relationship between the planetary shaft portion 1423s of the output-side planetary gear 1423 and the first bearing portion 1433 and the second bearing portion 1443, and the relationship between the planetary shaft portion 1424s of the output-side planetary gear 1424 and the first bearing portion 1434 and the second bearing portion 1444.

[0056] The following describes the rotational action of the output-side planetary gear mechanism 102 when the output shaft 2 is undergoing a axial offset phenomenon with a displacement in the Y direction + side. Figure 11 This diagram illustrates the shaft offset phenomenon where the output shaft 2 is displaced in the Y-direction + side. When the output shaft 2 is displaced in the Y-direction + side, the output shaft connection 1427 also shifts in the Y-direction + side, and the position of the output side bracket axis CC deviates from the position of the output side sun gear axis SC in the Y-direction + side by a distance equal to the interval G2 (see...). Figure 12 ).

[0057] At this time, the output side bracket 1425 is displaced to the + side in the Y direction as a whole, and the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444 are also displaced to the + side in the Y direction at all angular positions around the output side bracket axis CC. Even so, the planetary shaft portions 1422s, 1423s, 1424s can still be displaced radially in the bracket within the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444. Furthermore, although the contact position of the planetary shaft portions 1422s, 1423s, 1424s that transmit the pressing force to the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444 changes, the planetary shaft portions 1422s, 1423s, 1424s can still maintain their predetermined orbital path O. For example, at the first time point when the planetary axis is located on the Y-direction + side at 1422s (see...) Figure 13A Corresponding to the amount of displacement of the first bearing portion 1432 and the second bearing portion 1442 in the Y direction, the planetary shaft portion 1422s moves radially inward toward the bracket (see...). Figure 13B Then, at the second time point, at 1422s, the planetary axis had rotated approximately 120° clockwise from the first time point (see...). Figure 13C The planetary shaft portion 1422s moves radially outward relative to the bracket. Even though the position of the planetary shaft portion 1422s and its contact position with the first bearing portion 1432 and the second bearing portion 1442 change with the rotational operation, the orbital path O of the planetary shaft portion 1422s is maintained. Therefore, the output-side planetary gear mechanism 102 can continue to operate while allowing for axial offset of the output shaft 2. Since it is not easy to apply excessive load between the components of the output-side planetary gear mechanism 102 during operation, the generation of abnormal noise can also be suppressed.

[0058] The following describes variations of this embodiment.

[0059] Figure 14 The variation shown in Example 1 is a variation concerning gear dimensions. In Figure 14In the modified example 1 shown, for example, a sun gear with a larger diameter than the output-side sun gear 1421 is used. Therefore, compared to the embodiment described above, the inter-axis distance of the output-side planetary gear mechanism 102, i.e., the interval distance (around the orbital radius R2) from the output-side sun gear axis SC and the output-side bracket axis CC to the planetary shafts 1422s, 1423s, and 1424s, is increased (R2>R1). Even so, the output-side bracket 1425 can still rotatably accommodate the planetary shafts 1422s, 1423s, and 1424s at a relatively outer position among the first bearing portions 1432, 1433, and 1434 and the second bearing portions 1442, 1443, and 1444. Thus, the output-side bracket 1425 can accommodate various inter-axis distances, thereby increasing the design freedom of the planetary gear device. In addition, if the inter-axis distance (radius around the track) of the output-side planetary gear mechanism 102 is increased while the dimensions of the output-side planetary gears 1422, 1423, and 1424 remain unchanged, then the inner diameter of the output-side internal gear 1221 needs to be increased.

[0060] Figure 15A , 15B The modified example 2 shown is a modification concerning the opening shape of the bearing portions (represented by the first bearing portion 1432 and the second bearing portion 1442). In this modification, the first bearing portion 1432 and the second bearing portion 1442 have an opening shape whose width linearly increases as they approach the radial direction from the inner side to the outer side of the bracket. Conversely, the first bearing portion 1432 and the second bearing portion 1442 have an opening shape whose width linearly decreases as they approach the radial direction from the outer side to the inner side of the bracket. With this opening shape, by changing the diameter of the planetary shaft portion 1422s, the length of its movable range can be adjusted while ensuring the movable range of the planetary shaft portion 1422s. For example, a planetary shaft portion 1422s with a diameter of D1 can be displaced to a position with a width of W1 (= diameter D1). However, if a planetary shaft portion 1422s with a diameter of D2 (> diameter D1) is used instead, the planetary shaft portion 1422s can only be displaced to a position with a width of W2 (= diameter D2). As a result, the range of motion is shortened from length L1 to length L2. This adjustment is effective in ensuring the ease of insertion of the output-side sun gear 1421.

[0061] Figure 16A , 16BThe modified example 3 shown, like modified example 2, is a modification concerning the opening shape of the bearing portion (represented by the first bearing portion 1432 and the second bearing portion 1442). In this modified example, the first bearing portion 1432 and the second bearing portion 1442 have an opening shape that gradually widens as they approach from the inner side to the outer side radially from the bracket. Conversely, the first bearing portion 1432 and the second bearing portion 1442 have an opening shape that gradually narrows as they approach from the outer side to the inner side radially from the bracket. Similarly, with this opening shape, by changing the diameter of the planetary shaft portion 1422s, the length of its movable range can be adjusted while ensuring the movable range of the planetary shaft portion 1422s. For example, the planetary shaft part 1422s with a diameter of D3 can be moved to a position with a width of W3 (= diameter D3), but if the planetary shaft part 1422s with a diameter of D4 (> diameter D3) is replaced, the planetary shaft part 1422s can only be moved to a position with a width of W4 (= diameter D4), resulting in the movable range being shortened from length L3 to length L4.

[0062] Figure 17 Similar to modifications 2 and 3, the modified example 4 shown relates to the opening shape of the bearing portion (represented by the first bearing portion 1432 and the second bearing portion 1442). As shown in this modified example, a narrowing can be partially added to the opening shape as an anti-detachment part to prevent the planetary shaft portion 1422s from dislodging from the first bearing portion 1432 and the second bearing portion 1442. In this case, as long as the planetary shaft portion 1422s has a diameter D5 equal to the width W5 (> width W6), the length L5 of the movable range can be ensured even if the diameter is larger than the width W6 of the narrowed portion.

[0063] As described above, according to this embodiment, the planetary gear device 100 includes an output-side sun gear 1421, an output-side internal gear 1221, output-side planetary gears 1422, 1423, and 1424, and an output-side bracket 1425. The output-side internal gear 1221 surrounds the outer periphery of the output-side sun gear 1421 and is arranged coaxially with the output-side sun gear 1421. The output-side planetary gears 1422, 1423, and 1424 have protruding planetary shaft portions 1422s, 1423s, and 1424s, which mesh with the output-side sun gear 1421 and the output-side internal gear 1221, and rotate around the output-side sun gear 1421 while rotating about the planetary shaft portions 1422s, 1423s, and 1424s. The output-side bracket 1425 has first bearing portions 1432, 1433, 1434 and second bearing portions 1442, 1443, 1444 that accommodate the planetary shaft portions 1422s, 1423s, 1424s in a manner that allows the planetary shaft portions 1422s, 1423s, 1424s to rotate. The output-side bracket 1425 outputs rotary motion by means of the pressing force transmitted from the planetary shaft portions 1422s, 1423s, 1424s via the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444 in the orbit of the output-side planetary gears 1422, 1423, 1424, rotating about the output-side bracket axis CC. In the first bearing portions 1432, 1433, 1434 and the second bearing portions 1442, 1443, 1444, particularly in the radial direction of the bracket, the planetary shaft portions 1422s, 1423s, 1424s can be displaced. This allows the planetary gear assembly 100 to continue operating while allowing for shaft offset of the output shaft 2, and it prevents excessive load from being applied between the components of the planetary gear assembly 100 during operation, thus suppressing abnormal noise. In other words, the planetary gear assembly 100 is less susceptible to external influences during operation and possesses robustness.

[0064] The embodiments of the present invention have been specifically described above, but the present invention is not limited to the specific embodiments described above. Various modifications and alterations can be made to the specific examples described in the above embodiments within the scope of the key points of the present invention as set forth in the claims.

[0065] Industrial applicability The planetary gear device of the present invention is useful as a planetary gear device for various actuators such as actuators for opening and closing rear doors.

Claims

1. A planetary gear mechanism, characterized in that, include: Sun gear; An internal gear surrounds the outer periphery of the sun gear and is configured to be on the same axis as the sun gear; The planetary gear has a protruding planetary shaft portion that meshes with the sun gear and the internal gear, and rotates around the sun gear while being centered on the planetary shaft portion; as well as The bracket has a bearing portion that accommodates the planetary shaft portion in a manner that allows the planetary shaft portion to rotate. Rotational motion is output by means of a pressing force transmitted from the planetary shaft portion via the bearing portion within the orbit of the planetary gears, rotating about the bracket's axis. Within the bearing section, the planetary shaft section is capable of displacement.

2. The planetary gear device as claimed in claim 1, wherein, In the bearing section, the abutting position of the planetary shaft section can be displaced radially in the bracket, and this abutting position is the position where the pressing force is transmitted.

3. The planetary gear device as claimed in claim 1, wherein, The planetary shaft can be displaced in accordance with the displacement of the bracket axis relative to the axis of the sun gear.

4. The planetary gear device as claimed in claim 3, wherein, When the planetary gear revolves in a state where the axis of the bracket has been displaced relative to the axis of the sun gear, the bearing portion causes the abutment position of the planetary shaft portion to change radially in the bracket, and this abutment position is the position to which the pressing force is transmitted.

5. The planetary gear device as claimed in claim 1, wherein, The bearing portion has an opening that extends radially along the bracket, in a manner that allows the planetary shaft portion to be displaced radially within the opening.

6. The planetary gear device as claimed in claim 5, wherein, The bearing section includes a first bearing section and a second bearing section disposed on both sides of the planetary gear in the axial direction of the bracket. The shape in the first bearing portion is the same as the shape in the second bearing portion.

7. The planetary gear device as claimed in claim 5, wherein, The shape is one that has a width that is greater than or equal to the diameter of the planetary shaft portion and is continuously arranged radially in the bracket.

8. The planetary gear device as claimed in claim 7, wherein, The shape is one in which the width narrows as the bracket moves radially from the outside to the inside.

9. The planetary gear device as claimed in claim 7, wherein, The planetary gear assembly also includes a housing having a cylindrical portion that surrounds a rotary motion output portion with a radial clearance from the bracket, the rotary motion output portion defining the bracket axis. The shape includes a free area that allows the planetary axis to be displaced to a position further inward than the position of the planetary axis when the rotational motion output portion abuts against the cylindrical portion.

10. A resin molded article, characterized in that, It is used as the bracket in the planetary gear assembly of claim 1.

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