Gear housing for a planetary gear unit with structurally separable internal gears

Abstract

This application provides an apparatus, a planetary gear assembly, and an actuator for suppressing noise generated in a planetary gear assembly. The apparatus for suppressing noise generated in a planetary gear assembly includes: an internal gear having a first protrusion formed on the outer peripheral surface of the internal gear, the first protrusion extending axially from one side of the internal gear to the other side; and a housing having a second protrusion formed on the inner peripheral surface of the housing, the second protrusion extending axially from one side of the housing to the other side, wherein the housing is configured to receive the internal gear such that a gap exists between the inner peripheral surface of the housing and the outer peripheral surface of the internal gear, wherein: movement of the internal gear within the housing is restricted by line contact between the first and second protrusions.

Description

Technical Field

[0001] This invention relates to a separate structural unit for an internal gear and a housing, a planetary gear assembly including said separate structural unit, and an actuator including said planetary gear assembly. Background Technology

[0002] Planetary gear systems are used in various technologies, such as automobiles and robotics. Because planetary gear systems are constructed using combinations of multiple gears, they generate noise and vibration during operation. Techniques have been proposed to suppress the generation of noise and vibration during the operation of planetary gear systems.

[0003] As one of such proposed technologies, Patent Document 1 discloses a planetary gear device having a structure that separates the internal gear from the housing, creating a gap between the internal gear and the housing. Using this structure, in which the internal gear and housing are separated, makes it more difficult for vibrations to be transmitted from the internal gear to the housing, thereby reducing noise generated by vibrations.

[0004] Existing technical references

[0005] Patent documents

[0006] Patent Document 1

[0007] Japanese Unexamined Patent Application Publication H6-74835 Summary of the Invention

[0008] Technical issues

[0009] In the planetary gear assembly of Patent Document 1, the outer peripheral surface of the internal gear and the inner peripheral surface of the housing are formed in a mating shape. Therefore, when the internal gear moves during operation of the planetary gear assembly, there is contact between the outer peripheral surface of the internal gear and the inner peripheral surface of the housing, and the contact area has a certain width. Consequently, in this contact state between the internal gear and the housing, vibrations propagating from the planetary gear mechanism to the internal gear are easily transmitted to the housing, thus presenting a problem: the planetary gear assembly also tends to generate noise.

[0010] The present invention aims to solve the problem areas described above, and aims to provide a separate structural unit for the internal gear and housing, capable of suppressing the transmission of vibrations from the planetary gear mechanism and noise generated by the planetary gear device, and capable of providing a planetary gear device equipped with the separate structural unit and an actuator equipped with the planetary gear device.

[0011] Technical solution

[0012] The structural unit for separating an internal gear and a housing according to the present invention comprises: an internal gear having a first protrusion formed on the outer peripheral surface, the first protrusion extending axially from one side to the other; and a housing wherein a second protrusion extending axially from one side to the other is formed on the inner peripheral surface, and the housing accommodates the internal gear in a state in which there is a gap with the inner peripheral surface, wherein: movement of the internal gear within the housing is restricted by line contact between the first protrusion and the second protrusion.

[0013] In the first protruding portion and the second protruding portion, one protruding portion may be formed as a pair with a gap between them, and another protruding portion may be configured to be easily inserted between the pair of protruding portions; and in the contact position of the one protruding portion and the contact position of the other protruding portion that are in line contact with each other, at least one contact position may be a curved surface.

[0014] The protruding portion may be the second protruding portion, and the other protruding portion may be the first protruding portion; and when cut by a plane perpendicular to the axial direction, the first protruding portion may have a triangular cross-section, and the first protruding portion may make line contact with the second protruding portion at an inclined surface formed in the plane.

[0015] In the contact positions of the first protrusion and the second protrusion, which are in line contact with each other, one contact position may be a convex surface and the other contact position may be a plane.

[0016] The contact positions of the first protrusion and the second protrusion, which are in line contact with each other, can be convex curved surfaces.

[0017] In the contact positions of the first protrusion and the second protrusion, which are in line contact with each other, one contact position may be a convex surface and the other contact position may be a concave surface.

[0018] The first protrusion and the second protrusion can make line contact along the axial direction, wherein the range of the line contact between the first protrusion and the second protrusion can be shorter than the axial width of the internal gear.

[0019] The length of the first protrusion extending on the internal gear may be shorter than the axial width of the internal gear.

[0020] The first protrusion may extend from only one end of the internal gear.

[0021] The first protrusion may extend from both ends of the internal gear, and the length of the first protrusion extending from both ends may be shorter than the axial width of the internal gear.

[0022] Multiple first protrusions may be spaced apart from each other along the axial direction on the internal gear.

[0023] The movement of the internal gear within the housing can be restricted by the line contact between the first protrusion and the second protrusion in a direction perpendicular to the axial direction.

[0024] In the first and second protruding portions, when cut by a plane perpendicular to the axial direction, one protruding portion may have a triangular cross-section, wherein the cross-sectional size of the triangle may vary depending on the position in the axial direction, and the contact with the other protruding portion is at the position with the largest cross-sectional size.

[0025] According to another aspect of the invention, a structural unit for separating an internal gear and a housing comprises: an internal gear having a first protrusion formed on the outer peripheral surface; and a housing having a second protrusion formed on the inner peripheral surface of the housing, the housing being configured to accommodate the internal gear in a state in which a gap is provided with respect to the inner peripheral surface, wherein: movement of the internal gear within the housing is restricted by point contact between the first protrusion and the second protrusion.

[0026] The first protrusion may be formed on the outer peripheral surface of the internal gear to extend axially from one side to the other, and the second protrusion may be formed on the inner peripheral surface of the housing to extend axially from one side to the other.

[0027] The protrusion may be formed on the first protrusion or the second protrusion at the contact position between the first protrusion and the second protrusion, and the first protrusion and the second protrusion may make point contact through the protrusion.

[0028] Multiple protrusions may be formed along the axial direction.

[0029] When cut by a plane perpendicular to the axis, the first protrusion may have a triangular cross-section, and the protrusion may be formed on an inclined surface forming the plane.

[0030] The internal gear and the housing may be made of synthetic resin; and the internal gear may be formed of a synthetic resin with a lower hardness than the synthetic resin used to form the housing.

[0031] The planetary gear assembly according to the invention comprises: a structural unit for separating the internal gear and the housing as described above; one or more planetary gears meshing with the internal gear; a sun gear meshing with the one or more planetary gears and positioned at the center of the one or more planetary gears; and a support rotatably supporting the one or more planetary gears.

[0032] The structure may further include a second sun gear that rotates in a manner similar to the rotation of the support as the support rotates; one or more second planetary gears disposed on the periphery of the second sun gear and meshing with the second sun gear; a second support that rotatably supports the one or more second planetary gears; and a second housing with internal teeth meshing with the one or more second planetary gears formed on the inner peripheral surface of the second housing, wherein the housing and the second housing may be integrally formed.

[0033] In another aspect of the invention, the planetary gear assembly includes at least two stages of planetary gear mechanisms, each stage comprising: a sun gear; one or more planetary gears arranged on the periphery of the sun gear for meshing with the sun gear; and a support rotatably supporting the one or more planetary gears, wherein: in the at least two stages of planetary gear mechanisms, the planetary gear mechanism operating at the highest speed includes a structural unit as described above for separating the internal gear and the housing, wherein the one or more planetary gears of the planetary gear mechanism mesh with the internal gear; and in the at least two stages of the planetary gear mechanisms, the planetary gear mechanism operating at the lowest speed includes a housing, wherein internal teeth meshing with the one or more planetary gears of the planetary gear mechanism are formed on the inner peripheral surface.

[0034] The actuator according to the invention comprises: a planetary gear assembly as described above; and a motor connected to the planetary gear assembly for driving the planetary gear assembly.

[0035] In one aspect of the invention, a device for suppressing noise generated in a planetary gear assembly includes: an internal gear and a housing. The internal gear has a first protrusion formed on its outer peripheral surface, the first protrusion extending axially from one side of the internal gear to the other side; the housing has a second protrusion formed on its inner peripheral surface, the second protrusion extending axially from one side of the housing to the other side, wherein the housing is configured to receive the internal gear such that a gap exists between the inner peripheral surface of the housing and the outer peripheral surface of the internal gear, wherein movement of the internal gear within the housing is restricted by line contact between the first protrusion and the second protrusion.

[0036] In some embodiments, one of the first and second protruding portions is formed in pairs with a gap between the paired protruding portions, while the other protruding portion is configured to be inserted between the paired protruding portions; and wherein the surface on one of the first and second protruding portions that contacts the surface on the other protruding portion is curved.

[0037] In some embodiments, the second protrusions are formed in pairs and have a gap between the pairs of second protrusions; and when truncated by a plane perpendicular to the axial direction, the first protrusion has a triangular cross-section, and the first protrusion contacts the second protrusion at an inclined surface formed in the plane.

[0038] In some embodiments, the surface of one of the protruding portions that contacts the surface of the other protruding portion is a convex surface, and the surface of the other protruding portion that contacts the surface is a plane.

[0039] In some embodiments, a portion of the first protrusion and a portion of the second protrusion that are in contact with each other are convex surfaces.

[0040] In some embodiments, the surface of one of the protruding portions and the second protruding portion that contacts the surface of the other protruding portion is a convex surface, and the surface of the other protruding portion that contacts the surface is also a convex surface.

[0041] In some embodiments, the first protrusion and the second protrusion are in contact along an axial line; and the length of the line contact between the first protrusion and the second protrusion is less than the axial width of the internal gear.

[0042] In some embodiments, the first protrusion extends on the internal gear by a length less than the axial width of the internal gear.

[0043] In some implementations, the first protrusion extends only from one end of the internal gear.

[0044] In some embodiments, the first protrusion extends from both ends of the internal gear; and the total length of the first protrusion extending from both ends is less than the axial width of the internal gear.

[0045] In some embodiments, a plurality of first protrusions spaced apart from each other are provided on the internal gear along the axial direction.

[0046] In some embodiments, the movement of the internal gear within the housing is restricted by a line contact between the first protrusion and the second protrusion in a direction perpendicular to the axial direction.

[0047] In some embodiments, when truncated by a plane perpendicular to the axial direction, one of the first and second protruding portions has a triangular cross-section, wherein the cross-sectional size of the triangle varies depending on its position in the axial direction, and wherein the contact between the first and second protruding portions is located at the position where the cross-sectional size of the triangle is largest.

[0048] In another aspect of the invention, an apparatus for suppressing noise generated in a planetary gear assembly includes an internal gear having a first protrusion formed on the outer peripheral surface of the internal gear; and a housing having a second protrusion formed on the inner peripheral surface of the housing, wherein the housing is configured to receive the internal gear such that a gap is provided between the inner peripheral surface and the outer peripheral surface, wherein movement of the internal gear within the housing is restricted by point contact between the first protrusion and the second protrusion.

[0049] In some embodiments, the first protrusion is formed to extend axially from one side of the internal gear to the other side of the internal gear, and the second protrusion is formed to extend axially from one side of the housing to the other side of the housing.

[0050] In some embodiments, a protrusion is formed on the first protrusion or the second protrusion at the contact position between the first protrusion and the second protrusion, and the first protrusion and the second protrusion make point contact through the protrusion.

[0051] In some embodiments, a plurality of the protrusions are formed along the axial direction.

[0052] In some embodiments, when cut by a plane perpendicular to the axis, the first protrusion has a triangular cross-section, and the protrusion is formed on an inclined surface forming the plane.

[0053] In some embodiments, the internal gear and the housing are made of synthetic resin; and the internal gear is formed of a synthetic resin with a lower hardness than the synthetic resin used to form the housing.

[0054] In another aspect of the invention, a planetary gear assembly includes: a device for suppressing noise generated in the planetary gear assembly as described above; one or more planetary gears meshing with the internal gear; a sun gear meshing with the one or more planetary gears and positioned at the center of the one or more planetary gears; and a support rotatably supporting the one or more planetary gears.

[0055] In some embodiments, the device further includes: a second sun gear that rotates together with the support; one or more second planetary gears disposed on the periphery of the second sun gear and meshing with the second sun gear; a second support that rotatably supports the one or more second planetary gears; and a second housing having internal teeth formed on its inner peripheral surface and meshing with the one or more second planetary gears, wherein the housing and the second housing are integrally formed.

[0056] In another aspect of the invention, a planetary gear device includes: at least two stages of planetary gear mechanisms, each stage including: a sun gear; one or more planetary gears arranged on the periphery of the sun gear for meshing with the sun gear; and a support rotatably supporting the one or more planetary gears, wherein, in the at least two stages of planetary gear mechanisms, the planetary gear mechanism operating at the highest speed includes the means for suppressing noise generated in the planetary gear device as described above, wherein the one or more planetary gears of the planetary gear mechanism mesh with the internal gear; and wherein, in the at least two stages of planetary gear mechanisms, the planetary gear mechanism operating at the lowest speed includes a housing having internal teeth formed on its inner peripheral surface, and the internal teeth mesh with the one or more planetary gears of the planetary gear mechanism.

[0057] In another aspect of the invention, an actuator includes: a planetary gear assembly as described above; and a motor connected to the planetary gear assembly for driving the planetary gear assembly.

[0058] Technical effect

[0059] In this invention, the contact range between the internal gear and the housing is narrower than that in the prior art, thereby reducing the transmission of vibrations caused by the planetary gear mechanism to the housing. This suppresses the transmission of vibrations from the planetary gear mechanism and also suppresses the noise generated by the planetary gear assembly that accompanies the vibrations of the planetary gear mechanism.

[0060] [Technical Issues]

[0061] In order to provide a separate structural unit for the internal gear and the housing, the structural unit enables the transmission of vibrations from the planetary gear mechanism and the suppression of noise generated by the planetary gear assembly.

[0062] [Solution and Technical Solution]

[0063] The structural unit for separating the internal gear and the housing includes: an internal gear, wherein a first protrusion extending axially from one side to the other is formed on an outer peripheral surface; and a housing, wherein a second protrusion extending axially from one side to the other is formed on an inner peripheral surface, and the housing accommodates the internal gear in a state where there is a gap with the inner peripheral surface. Movement of the internal gear within the housing is restricted by line contact between the first and second protrusions. Attached Figure Description

[0064] Figure 1 This is a perspective view of an actuator according to a first embodiment of the present invention.

[0065] Figure 2 From Figure 1 Arrow AII in the diagram shows the front view of the actuator.

[0066] Figure 3 In order to be in Figure 2 The cross-sectional view of the actuator taken from section line III-III in the diagram.

[0067] Figure 4 This is an assembly perspective view of the actuator according to a first embodiment of the present invention.

[0068] Figure 5 This is a cross-sectional view of the second housing according to a first embodiment of the present invention.

[0069] Figure 6 This is a perspective view of the second housing according to a first embodiment of the present invention.

[0070] Figure 7 This is a perspective view of a first planetary gear mechanism according to a first embodiment of the present invention.

[0071] Figure 8 This is a perspective view of a second planetary gear mechanism according to a first embodiment of the present invention.

[0072] Figure 9 A diagram illustrating the relationship between the second housing and the internal gear according to a first embodiment of the present invention.

[0073] Figure 10 To focus on the formation of Figure 9 An illustrative diagram of the stop in the second housing shown.

[0074] Figure 11 To focus on the formation of Figure 9 An illustrative diagram of the movement-limiting protrusion on the internal gear shown.

[0075] Figure 12 For the purpose of illustration Figure 9 The diagram shows the state in which the internal gear rotates about its axis and comes into contact with the second housing.

[0076] Figure 13 For the purpose of illustration Figure 9 The diagram shows the state in which the internal gear moves in a direction perpendicular to the axis and comes into contact with the second housing.

[0077] Figure 14 For the purpose of illustrating when from Figure 12 The diagram shows the contact state between the second housing and the internal gear when observed by arrow XIV.

[0078] Figure 15 To be Figure 11 The diagram shown compares the movement restriction protrusion with another example of a movement restriction protrusion.

[0079] Figure 16 A diagram illustrating an internal gear according to a second embodiment of the present invention.

[0080] Figure 17 This is a cross-sectional view of the second housing according to a second embodiment of the present invention.

[0081] Figure 18 A diagram illustrating an internal gear according to a third embodiment of the present invention.

[0082] Figure 19 This is a cross-sectional view of the second housing according to a third embodiment of the present invention.

[0083] Figure 20 A diagram illustrating an internal gear according to a fourth embodiment of the present invention.

[0084] Figure 21 This is a cross-sectional view of the second housing according to a fourth embodiment of the present invention.

[0085] Figure 22 This is a perspective view of an internal gear according to a fifth embodiment of the present invention.

[0086] Figure 23 An illustrative diagram showing the state of separation of the internal gear and the second housing according to a fifth embodiment of the present invention.

[0087] Figure 24 An illustrative diagram showing the state of contact between the internal gear and the second housing according to a fifth embodiment of the present invention.

[0088] Figure 25 This is a perspective view of an internal gear according to a sixth embodiment of the present invention.

[0089] Figure 26 An illustrative diagram showing the state of separation of the internal gear and the second housing according to the sixth embodiment of the present invention.

[0090] Figure 27 An illustrative diagram showing the state of contact between the internal gear and the second housing according to a sixth embodiment of the present invention.

[0091] Figure 28 This is a perspective view of an internal gear according to a seventh embodiment of the present invention.

[0092] Figure 29 An illustrative diagram showing the state of separation of the internal gear and the second housing according to the seventh embodiment of the present invention.

[0093] Figure 30 An illustrative diagram showing the state of contact between the internal gear and the second housing according to the seventh embodiment of the present invention.

[0094] Figure 31 An illustrative diagram for focusing on the contact position between the internal gear and the second housing according to another embodiment of the present invention. Detailed Implementation

[0095] The following description, with reference to the accompanying drawings, illustrates a structural unit for separating the internal gear and housing, a planetary gear assembly, and an actuator according to a preferred embodiment of the invention. It should be noted that, for ease of understanding, an orthogonal coordinate system is shown in each drawing, wherein the X-axis is parallel to the axial direction of the actuator 1 according to an embodiment of the invention, and the Y and Z axes are perpendicular to the X-axis.

[0096] (Implementation Plan 1)

[0097] (Structure of Actuator 1)

[0098] like Figure 1 and Figure 2 As shown, actuator 1 includes, for example, a motor 10 and a planetary gear assembly 20 connected to the motor 10.

[0099] Motor 10 has, for example, a motor main unit 11 and a rotating shaft 12, such as Figure 3 and Figure 4 As shown. Under the control of a control unit (not shown), the motor 10 rotates the rotating shaft 12 to drive the planetary gear unit 20.

[0100] Planetary gear unit 20 reduces the speed of the gears from the specified reduction ratio. Figure 1 The motor 10 shown is input to rotation and outputs it to the output gear 86a. The planetary gear unit 20 includes, for example, a housing 50 and a planetary gear mechanism 60 housed within the housing 50, the housing having a first housing 30 and a second housing 40, as... Figure 3 and Figure 4 As shown.

[0101] The first housing 30 is a component used, for example, to attach the motor 10 to the planetary gear mechanism 20. Furthermore, the first housing 30 is assembled with the second housing 40 to form a receiving space S for accommodating the planetary gear mechanism 60, such as... Figure 5 As shown. Figure 4 As shown, an opening 30a is formed at the center of the first housing 30, and the rotating shaft 12 of the motor 10 passes through this opening. The rotating shaft 12 passing through the opening 30a is fixed (connected) to the sun gear 71 of the planetary gear mechanism 60, as described below. The first housing 30 is formed by injection molding and is made of, for example, synthetic resin.

[0102] The second housing 40 is open on the side connected to the first housing 30 (“one side”), for example, as Figure 5 and Figure 6 As shown, and Figure 4 The planetary gear mechanism 60 shown can be accommodated in a second housing from this open portion. For example, as... Figure 4 As shown, the planetary gear mechanism 60 has a first planetary gear mechanism 70, a second planetary gear mechanism 80, and an output gear 86a arranged axially. The planetary gear mechanism 60 reduces the (input) rotation generated by the motor 10 in two stages and outputs it from the output gear 86a. For example, as Figure 5 As shown, the second housing 40 has a first position 41 in which the first planetary gear mechanism 70 is accommodated, a second position 42 in which the second planetary gear mechanism 80 is accommodated, and a third position 43 in which the output gear 86a of the second planetary gear mechanism 80 protrudes outward.

[0103] For example, such as Figure 5 and Figure 6 As shown, the first position 41 of the second housing 40 has a cylinder 44 and a stop (second protrusion) 45 extending axially (from one side of the axial direction to the other). When divided by a cross-section perpendicular to the axial direction, the stop 45 has a herringbone-shaped cross-section, wherein its shape and dimensions are constant in the axial direction. The stop 45 is formed axially within a portion of the first position 41, but alternatively, it can be formed over its entire range. For example, as... Figure 9 As shown, the stop members 45 are arranged in pairs along the circumferential direction of the inner wall 44a of the cylinder 44. For example, the pairs of stop members 45 are arranged at six positions on the inner wall 44a of the cylinder 44 at equal intervals. For example, as... Figure 10 As shown, the cross-sectional shape of each stop 45 has an upright portion 45a forming an arc that gradually rises from the inner wall 44a of the cylinder 44, a rounded top 45c, and a connecting portion 45b for connecting the upright portion 45a and the top 45c during bulging. It should be noted that the shape and dimensions of the cross-section of the stop 45 are constant in the axial direction. Therefore, for example, from... Figure 6 It can be understood that the upright part 45a, the connecting part 45b, and the top 45c are curved surfaces that do not bend in a direction parallel to the axis. Figure 9 The movement-limiting protrusion 75 of the internal gear 74 shown and described below is inserted between the pairs of stops 45 to limit the movement of the internal gear 74 within the second housing 40.

[0104] For example, such as Figure 5 and Figure 6As shown, the second position 42 of the second housing 40 has a cylinder 46 and an internal toothed portion 47 formed on the inner wall of the cylinder 46. The internal toothed portion 47 is oblique, for example, at an angle relative to the axial direction. That is, the second position 42 where the internal toothed portion 47 is present is configured, for example, as a helical gear.

[0105] The third position 43 of the second housing 40 is formed, for example, a cylinder, and has an opening 43a through which the output gear 86a of the planetary gear mechanism 60 passes, such as... Figure 4 As shown. The torque output from the output gear 86a can be transmitted to an external mechanism. The second housing 40 is formed by injection molding and is made of, for example, synthetic resin.

[0106] Additionally, for convenience in this instruction manual, Figures 4 to 6 In this design, the side of the second housing 40 that is open for attachment to the first housing 30 is referred to as "one side" (-X direction side), and the side of the second housing 40 with the opening 43a at the third position 43 is referred to as "the other side" (+X direction side), which are opposite sides. However, the invention is not limited thereto, and the side of the second housing 40 with the opening 43a at the third position 43 may be referred to and interpreted as one side, and the side of the second housing 40 that is open for attachment to the first housing 30 may be referred to and interpreted as the other side.

[0107] For example, such as Figure 4 As shown, the planetary gear mechanism 60 is housed within the housing 50 and reduces the rotation transmitted from the motor 10 and outputs it from the output gear 86a. The planetary gear mechanism 60 has, for example, a first planetary gear mechanism 70 and a second planetary gear mechanism 80 arranged axially.

[0108] For example, such as Figure 7 As shown, the first planetary gear mechanism 70 includes: a sun gear 71; three(multiple) planetary gears 72 arranged around the periphery centered on the sun gear 71; a support 73 for rotatably supporting the three(multiple) planetary gears 72; and an internal gear 74. It should be noted that, although for convenience, in... Figure 7 The perspective view shows only two planetary gears 72, but another planetary gear 72 is located on the back side and is blocked by the bracket 73.

[0109] The sun gear 71 is an external gear having a sun tooth portion 71a formed on its outer peripheral surface, and Figure 4 The rotating shaft 12 of the motor 10 shown is fixed (connected) to the external gear. In this way, the sun gear 71 rotates by the operation of the motor 10. The sun gear portion 71a has helical teeth that are cut at an angle relative to the axis of the sun gear 71, for example. That is, the sun gear 71 is, for example, a helical gear.

[0110] Planetary gear 72 is, for example, an external gear, wherein planetary tooth portions 72a are formed on its outer peripheral surface. The planetary tooth portions 72a have, for example, helical teeth that are angled relative to the axis of the planetary gear 72. That is, planetary gear 72 is, for example, a helical gear. Three planetary gears 72 are arranged at equal intervals on the same circle centered on the axis of the first planetary gear mechanism 70. A sun gear 71 is positioned between the three planetary gears 72, wherein the sun tooth portion 71a meshes with the corresponding planetary tooth portions 72a of the three planetary gears 72.

[0111] The support 73 is formed, for example, in a cylindrical shape, wherein three receiving openings 73a for receiving the planetary gears 72 are formed in the outer peripheral surface of the support. Each of the planetary gears 72 is rotatably supported within a corresponding receiving opening 73a by an axially facing pin 76, as shown below. Figure 3 As shown. The planetary gear 72 is attached with, for example, a portion of the planetary tooth portion 72a protruding from the outer peripheral surface of the support 73. Thus, the planetary tooth portion 72a can mesh with the internal tooth portion 74a of the internal gear 74, as described below.

[0112] The internal tooth portion 74a is formed on the inner peripheral surface of the internal gear 74, such as, for example... Figure 3 and Figure 7 As shown. The internal gear portion 74a is, for example, a helical gear, which has helical teeth that are angled relative to the axis of the internal gear 74. The rounded diameter of the tooth tips of the internal gear 74 is larger than the diameter of the cylindrical support 73. Therefore, the support 73 holding the planetary gear 72 is accommodated inside the internal gear 74. The planetary gear portion 72a, which protrudes from the outer peripheral surface of the support 73, meshes with the internal gear portion 74a of the internal gear 74.

[0113] Furthermore, a movement-limiting protrusion (first protrusion) 75, which enters the gap between a pair of stoppers 45 formed on, for example, the inner wall 44a of the second housing 40, is formed on the outer peripheral surface of the internal gear 74, such as... Figure 9 As shown. Movement-limiting protrusions 75 are provided corresponding to, for example, pairs of stops 45 formed in six positions, similar to the pairs of stops 45. When divided by a plane perpendicular to the axial direction, the movement-limiting protrusions 75 have a substantially triangular cross-section. Figure 11 As shown, the movement-restricting protrusion 75 has, for example, a straight, inclined edge portion 75a rising from the outer peripheral surface 74b of the internal gear 74, and a rounded top 75b positioned at the intersection of the inclined edge portions 75a rising from both sides. It should be noted that, as Figure 7As shown, the cross-sectional shape and dimensions of the movement-restricting protrusion 75 are constant in the axial direction (having a constant axial extension from one side to the other), and therefore the inclined edge portion 75a of the movement-restricting protrusion 75 constructs a planar region. It should be noted that although the movement-restricting protrusions 75 are formed over the entire width of the internal gear 74, they can alternatively be formed only in a portion of the range of the internal gear. Furthermore, as... Figure 7 As shown, a hemispherical protrusion 74b is formed on the end face of the internal gear 74 on the +X direction side. The hemispherical protrusion 74b is formed in each gap between adjacent movement-limiting protrusions 75, in a total of six positions. When the internal gear 74 is received in the first position 41 of the second housing 40, as... Figure 5 As shown, the tops of the six protrusions 74b will contact the stepped surface 46a. Figure 5 and Figure 6 The stepped surface forms the boundary between the first position 41 and the second position 42 of the second housing 40. Considering that the contact between a spherical surface and a plane is a point contact, the contact between the protrusion 74b and the stepped surface 46a is also a point contact. The internal gear 74 is made of, for example, synthetic resin. It should be noted that, as described below, the internal gear 74 is formed with a hardness ratio... Figure 9 The second shell 40 shown is formed of a synthetic resin with low hardness.

[0114] like Figure 9 As shown, the second housing 40 and the internal gear 74 are physically separated, and a gap is formed between the second gear and the internal gear when the actuator 1 is not operated. Therefore, the internal gear 74 is in a floating state within the second housing 40, allowing rotation about the axial direction and allowing movement within the second housing 40 in a direction perpendicular to the axial direction by an amount corresponding to the gap between the internal gear 74 and the second housing 40. Furthermore, further movement of the internal gear 74 is prevented by a stop 45 formed on the internal gear 74 that restricts contact movement against the protrusion 75.

[0115] The second planetary gear mechanism 80 (which is another planetary gear mechanism) includes, for example, a sun gear 81, three planetary gears 82, a support 83 rotatably supporting the three planetary gears 82, and an output shaft 86, such as Figure 8 As shown. It should be noted that, although for convenience, in Figure 8 The perspective view shows only two planetary gears 82, but another planetary gear 82 is located on the back side and is blocked by the bracket 83.

[0116] The sun gear 81 is an external gear, on which the sun tooth portion 81a is formed on, for example, the outer peripheral surface, and is fixed (connected) to the support 73 of the first planetary gear mechanism 70 with the axes aligned together. Figure 7 As shown. Therefore, as the support 73 of the first planetary gear mechanism 70 rotates, the sun gear 81 will rotate in the same direction as the support 73 of the first planetary gear mechanism 70 (linked for synchronization). That is, as the support 73 of the first planetary gear mechanism 70 rotates, the sun gear 81 rotates at the same speed as the support 73 of the first planetary gear mechanism 70 because its direction of rotation is the same as that of the support 73 of the first planetary gear mechanism 70. The sun gear portion 81a has, for example, helical teeth that are angled relative to the axis of the sun gear 81. That is, the sun gear 81 is, for example, a helical gear.

[0117] Planetary gear 82 is, for example, an external gear, wherein planetary tooth portions 82a are formed on its outer peripheral surface. The planetary tooth portions 82a have, for example, helical teeth that are angled relative to the axis of the planetary gear 82. That is, planetary gear 82 is, for example, a helical gear. For example, three planetary gears 82 are arranged at equal intervals on the same circle centered on the axis of the second planetary gear mechanism 80. A sun gear 81 is positioned between the three planetary gears 82, wherein the sun tooth portion 81a meshes with the corresponding planetary tooth portions 82a of the three planetary gears 82. Additionally, the planetary gears 82 mesh with internal tooth portions 47 formed on the second housing 40, such as... Figure 5 and Figure 6 As shown.

[0118] The support 83 has, for example, a gear retaining portion 84 for retaining planetary gears 82 and an output shaft retaining portion 85 for retaining an output shaft 86. The gear retaining portion 84 is formed, for example, in a cylindrical shape, wherein three receiving openings 84a for receiving the planetary gears 82 are formed in the outer peripheral surface of the support. Each of the planetary gears 82 is rotatably attached to a corresponding receiving opening 84a by an axially facing pin 87, as shown below. Figure 3 As shown. The planetary gear 82 is attached with a portion of its planetary tooth portion 82a protruding from the outer peripheral surface of the support 83. This makes it possible for the planetary tooth portion 82a to mesh with the internal tooth portion 47 formed on the second housing 40. Furthermore, as... Figure 8 As shown, the output shaft holding portion 85 is formed as a cylinder with a diameter smaller than that of the gear holding portion 84, and a mounting hole 85a for holding the output shaft 86 is formed in the center portion of the output shaft holding portion 85.

[0119] The output shaft 86 is held, for example, on the bracket 83 and rotates together with the bracket 83. The output shaft 86 has an output gear 86a, which has knurled teeth on the shaft. That is, the output shaft 86 is constructed as a gear, for example, having knurled teeth.

[0120] (Operation of Actuator 1)

[0121] The following will illustrate an example of the operation of actuator 1. First, when Figure 4 When the motor 10 shown is in operation, the rotating shaft 12 rotates in a first direction or a second direction. The following description will focus on the case where the rotating shaft 12 rotates in the first direction.

[0122] It should be noted that, relative to the rotation direction of each component in the structure, the first direction is when rotating from... Figure 1 The arrow AII indicates a clockwise direction when viewing all components. On the other hand, the second direction is the direction of rotation relative to each component within the group, when viewed from... Figure 2 The arrow AII shown indicates the counter-clockwise direction when observing all components.

[0123] When the rotating shaft 12 rotates in the first direction, the sun gear 71 (in) Figure 3 and Figure 7 (As shown in the diagram) it rotates in the first direction as the rotating shaft 12 rotates. As the sun gear 71 rotates in the first direction, the three planetary gears 72 meshing with the sun gear 71 each rotate in the second direction. Furthermore, because the planetary gears 72 mesh with the internal gear 74, they rotate (revolve) about the axis of the first planetary gear mechanism 70 in the first direction by rotating in the second direction. As the planetary gears 72 rotate (revolve), the support 73 rotates in the first direction around its own axis.

[0124] Thus, when the bracket 73 rotates in the first direction, the sun gear 81 fixed by the bracket 73 (in) Figure 3 and Figure 8 (As shown in the diagram) it will rotate in the first direction. As the sun gear 81 rotates in the first direction, the three planetary gears 82 meshing with the sun gear 81 each rotate in the second direction. Furthermore, because the planetary gears 82 mesh with the internal gear portion 47, as... Figure 5 and Figure 6 As shown, they rotate (revolve) about the axis of the second planetary gear mechanism 80 in the first direction by rotating in the second direction. As the planetary gear 82 rotates (revolve) in the first direction, the support 83 rotates about its own axis in the first direction. In view of this, the rotation of the support 83 is transmitted to the output shaft 86 held on the support 83.

[0125] Although the above description describes the case where the rotating shaft 12 rotates in the first direction, the description of the operation of the actuator 1 would be the same if the rotating shaft 12 rotates in the second direction, except that the rotation direction of each gear in the gear is opposite.

[0126] As described above, the second housing 40 and the internal gear 74 are physically separated. Furthermore, when the actuator 1 is not operated, a gap is formed between the second housing 40 and the internal gear 74. Therefore, when the actuator 1 is operated, the internal gear 74 can rotate about the axis of the second housing 40, or move in a direction perpendicular to the axis by an amount equivalent to the provided gap. For example, when the internal gear 74 moves from... Figure 9 When rotating in the first direction (clockwise) as shown, each of the plurality of movement-limiting protrusions 75 formed on the internal gear 74 will soon come into contact with the corresponding stop 45 formed on the second housing 40, as... Figure 12 As shown. Therefore, the internal gear 74 cannot rotate further in the clockwise direction. Because the stop members 45 are formed in pairs, even if the internal gear 74 rotates in the second direction (counterclockwise), the rotation of the internal gear 74 about the axis will be limited by the same line contact.

[0127] In addition, internal gear 74 from Figure 9 The state shown moves in a direction perpendicular to the axis, for example, moving upwards in the diagram. Therefore, as... Figure 13 As shown, the movement-limiting protrusion 75 formed on the upper part of the internal gear 74 makes line contact with the stop 45 formed on the second housing 40. Therefore, the internal gear 74 cannot move further in the upward direction, and its movement in the direction perpendicular to the axis is restricted. Furthermore, in this case, the top 75b of the internal gear 74 (more specifically, the top 75b of the movement-limiting protrusion 75) will not contact the second housing 40 (or more specifically, the inner wall 44a of the cylinder 44). It should be noted that the restriction on the movement of the internal gear 74 in the direction perpendicular to the axis is not limited to the upward movement of the internal gear 74. Because the six movement-limiting protrusions 75 and the stop 45 are arranged at equal intervals in the circumferential direction, they are able to restrict the movement of the internal gear 74 in various directions (e.g., vertical, lateral, and diagonal).

[0128] (Effect)

[0129] In view of the above implementation scheme, even in a structural unit in which the internal gear 74 and the second housing 40 are separated, the internal gear 74 will move during the operation of the actuator 1, and the stop 45 and the movement limiting protrusion 75 will make line contact, thereby limiting the movement of the internal gear 74. Figure 12 The diagram illustrates the line contact state between the internal gear 74 and the second housing 40 due to rotation of the internal gear 74 about its axis. In this case, the stop 45 and the movement-limiting protrusion 75 are in contact in all six positions, and the form of contact is the same in all positions. Therefore, reference will be made to... Figure 12The enlarged view in the figure illustrates the single contact location at the top of the figure. As shown, the contact location between the connecting portion 45b of the stop 45 (shown by the bulging convex curve) and the inclined edge portion 75a of the movement limiting protrusion 75 (shown by the straight line) can be depicted as contact point P1. That is, this contact will be within a very limited range. It should be noted that the cross-sections of the second housing 40 and the internal gear 74 have constant shapes and dimensions in the axial direction. Therefore, the contact between the connecting portion 45b and the inclined edge portion 75a will be a contact between a convex surface without curvature in the direction parallel to the axis and a plane parallel to the axis. Therefore, the contact between the internal gear 74 and the second housing 40 will be a line contact along the axial direction parallel to the X-axis, and with Figure 14 The contact area shown is the same as 90.

[0130] also, Figure 13 The diagram illustrates the contact state between the second housing 40 and the internal gear 74 via movement of the internal gear 74 in a direction perpendicular to the axis (e.g., upward movement in the figure). Figure 13 As shown, the contact positions between the second housing 40 and the internal gear 74 are indicated by four positions from contact points P2 to P5. Figure 13 As shown in the enlarged view, contact points P2 and P3 are the contact locations between the connecting portion 45b of the stop 45 (shown by the bulging convex curve) and the inclined edge portion 75a of the movement-limiting protrusion 75 (shown by a straight line). In the same manner as described above, such contact locations are line contacts between the two, assumed to be a contact between a convex surface without curvature in the direction parallel to the axis and a plane parallel to the axis. Furthermore, the contact between the stop 45 and the movement-limiting protrusion 75 at contact points P4 and P5 will also be line contacts, as they are contacts between a convex surface and a plane.

[0131] In this way, by providing a pair of herringbone-shaped stoppers 45 (with convex curved surfaces) and configuring them to facilitate the insertion of triangular movement-limiting protrusions 75 (with flat inclined surfaces) therebetween, the contact between the outer peripheral surface of the internal gear 74 and the inner peripheral surface of the second housing 40 can be made into line contact, even when the internal gear 74 has rotated about the axis and even when the internal gear has moved in a direction perpendicular to the axis. Since the contact area between the outer peripheral surface of the internal gear 74 and the inner peripheral surface of the second housing 40 is small (in this way, line contact), the vibration transmitted from the internal gear 74 to the second housing 40 during operation will be reduced. This suppresses the vibration of the second housing 40 generated by the first planetary gear mechanism 70, thereby suppressing the noise generated from the planetary gear unit 20 with the vibration caused by the first planetary gear mechanism 70.

[0132] It should be noted that the term "line contact" as described in this specification refers to a contact state in which the contact portions form a line, and it indicates not only a contact state shown by a single point or multiple points that are contact points in each individual cross-section, but also... Figure 14 As shown, this includes contact states where the width W is considered sufficiently small compared to the length L in the contact area 90. Furthermore, the term "line contact" as used in this specification also includes contact states where the contact is discontinuous (sporadic contact), such that when an imaginary line is drawn axially, the width W in the contact area 90 will form a line contact state. Additionally, the term "line contact" as used in this specification also includes contact states where the width W in the contact area 90 forms a line described as an angle rather than an axial line. Furthermore, the term "line contact" as used in this specification also includes contact states where the contact is discontinuous (sporadic contact), such that when an imaginary line is drawn as an angled line rather than axially, the width W in the contact area 90 will form a line contact state.

[0133] Furthermore, a hemispherical protrusion 74b is formed on the end face of the internal gear 74 on the +X direction side, where the protrusion 74b contacts the stepped surface 46a of the second housing 40. Figure 5 and Figure 6 The contact between the protrusion 74b and the stepped surface 46a can be maintained within a limited range, i.e., point contact. This reduces vibration transmitted from the internal gear 74 during operation to the second housing 40.

[0134] In addition, such as Figure 11 As shown, the cross-section of the movement-restricting protrusion 75, cut by a plane perpendicular to the axis, is triangular to create an outward-facing top 75b (narrow at the top) that allows the internal gear 74 to be easily removed from the mold during injection molding. This improves yield.

[0135] In addition, such as Figure 15 As shown, in a cross-section taken from a plane perpendicular to the axial direction, the movement-restricting protrusion 75 has straight, inclined edge portions 75a formed on both sides. Furthermore, Figure 15 A motion-limiting protrusion 100 is shown as a reference example of a motion-limiting protrusion 75, the shape of which is indicated by a double-dotted dashed line, wherein both sides are bulging. Comparing the two, the cross-sectional area of ​​the motion-limiting protrusion 75 is reduced by an amount equivalent to the area indicated by the shaded line compared to the cross-sectional area of ​​the motion-limiting protrusion 100. In view of this, this embodiment can reduce the load on the motor 10 by reducing the weight of the internal gear 74, and also reduce manufacturing costs. Furthermore, since the weight of the operating internal gear 74 is reduced, the present invention can reduce (suppress) the impact when the internal gear 74 contacts the second housing 40, thereby also reducing (suppressing) the vibration of the second housing.

[0136] Furthermore, the internal gear 74 is formed of a synthetic resin with a lower hardness than the synthetic resin used to form the second housing 40. From the perspective of mechanical strength, wear resistance, and thermal durability, it is preferable that the synthetic resin used to form the internal gear 74 and the second housing 40 is an engineering plastic or a super engineering plastic. These synthetic resins can be, for example, ultrapolymer polyethylene (UHPE), polyphenylene sulfide (PPS), polyarylate (PAR), polyoxymethylene (POM), polyamide (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethersulfone (PES), polyetheretherketone (PEEK), etc.

[0137] The synthetic resins used to form the internal gear 74 and the second housing 40 may be the same material or different materials. They may be suitably selected within the range that produces the effects of the present invention.

[0138] Among the aforementioned synthetic resins, the relatively soft synthetic resin suitable for forming the internal gear 74 is preferably, for example, ultrapolymer polyethylene (UHPE), polyphenylene sulfide (PPS), polyarylate (PAR), polyoxymethylene (POM), or polyamide (PA). Furthermore, the relatively hard synthetic resin suitable for forming the second housing 40 is preferably, for example, polycarbonate (PC), polybutylene terephthalate (PBT), polyethersulfone (PES), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyoxymethylene (POM), or polyamide (PA). Moreover, when synthetic resin materials having the same main components are used for forming the internal gear 74 and the second housing 40, preferably, by changing, for example, the density of the synthetic resin, the synthetic resin used to form the second housing 40 will be harder.

[0139] By forming the internal gear 74 from a synthetic resin with a hardness lower than that of the second housing 40, the impact when the internal gear 74 contacts the second housing 40 can be mitigated, thereby reducing (suppressing) vibrations generated within the second housing 40. In this way, the present invention can reduce (suppress) noise caused by vibrations of the second housing 40, and further reduce (suppress) noise when the internal gear 74 collides with the second housing 40. Therefore, noise generated from the planetary gear assembly 20 due to vibrations caused by the first planetary gear mechanism 70 can be suppressed.

[0140] Furthermore, in this embodiment, the structure in which the housing and internal gear are separated is applied only to the first planetary gear mechanism that rotates at high speed, and not to the second-stage planetary gear mechanism that rotates at low speed. That is, in this embodiment, the structure that allows the internal gear to float is used in mechanisms that rotate at high speed and tend to generate large vibrations and noise, while the housing structure forming the internal gear is used in mechanisms that rotate at low speed, where vibrations and noise tend to be relatively small. In this way, this embodiment not only suppresses the vibration and noise of the planetary gear unit caused by the planetary gear mechanism, but also prevents the number of parts in the planetary gear unit from increasing beyond the necessary number, and prevents an increase in assembly operations and assembly costs. Therefore, it is possible to reduce the manufacturing cost of the planetary gear unit. Thus, depending on the situation, two mechanisms with different structures can be used, specifically depending on the rotational form of the planetary gear mechanism, and these two mechanisms can be used in parallel.

[0141] Next, another embodiment of the invention will be described, but many features are the same as those in the first embodiment. Therefore, the following description will focus on the different features, and those identical features will be given the same reference numerals, and their detailed descriptions will be omitted.

[0142] (Implementation Plan 2)

[0143] In the first implementation scheme, such as Figure 7 As shown, six movement-limiting protrusions 75 are formed over the entire width of the internal gear 74. However, in the second embodiment, the six movement-limiting protrusions 275 are formed only within a portion of the entire width of the internal gear 274, where this point differs from the point in the structure of the first embodiment. It should be noted that the other structural details are the same as in the first embodiment. Figure 16 As shown, on the +X axial side of the internal gear 274, the movement-limiting protrusion 275 is formed only about half its width along the axial direction (X-axis). Note that the cross-section of the movement-limiting protrusion 275 is triangular. On the other hand, the movement-limiting protrusion 275 is not formed on the -X axial side approximately at the center of the internal gear 274. Through the internal gear 274 housed at the first position 41 of the second housing 40, as... Figure 17 As shown, the movement-limiting protrusion 275, formed only on the central +X axial side, is inserted between the pairs of stops 45. This allows the line contact length along the X-axis between the movement-limiting protrusion 275 and the stops 45 to be approximately half the length in the first embodiment. In this way, the contact area between the outer peripheral surface of the internal gear 274 and the inner peripheral surface of the second housing 40 can be further reduced, thereby reducing the transmission of vibrations from the internal gear 274 to the second housing 40 during operation.

[0144] (Implementation Plan 3)

[0145] In the second embodiment, the movement-limiting protrusion 275 provided on the internal gear 274 is positioned above approximately half its width on the +X axial side. On the other hand, as... Figure 18 As shown, in the third embodiment, on the internal gear 374, a movement limiting protrusion 375a is positioned approximately one-quarter of its width from its end portion on the +X axial side, and a movement limiting protrusion 375b is positioned approximately one-quarter of its width from its end portion on the -X axial side. The cross-sections of the movement limiting protrusions 375a and 375b are triangular. Figure 19 As shown, when the internal gear 374 is received in the first position 41 of the second housing 40, the movement-limiting protrusion 375a formed by the end portion on the +X axial side and the movement-limiting protrusion 375b formed by the end portion on the -X axial side are inserted between the pair of stops 345. In order to allow the insertion of the movement-limiting protrusion 375b formed on the end portion on the -X axial side, the pair of stops 345 is formed to be longer in the -X axial direction compared to the pair of stops 45 in the second embodiment. Therefore, as... Figure 19 As shown, a pair of stops 345 are provided that extend substantially over the entire range of the space in which the second housing 40 accommodates the internal gear 374.

[0146] A movement limiting protrusion 375a is formed above one-quarter of the X-axis width of the internal gear 374, and a movement limiting protrusion 375b is formed above one-quarter of the width. That is, both are formed together above approximately half the width of the internal gear 374. Therefore, the contact area between the outer peripheral surface of the internal gear 374 and the inner peripheral surface of the second housing 40 can be reduced to half the contact area in the first embodiment, thereby reducing the transmission of vibrations from the internal gear 374 to the second housing 40 during operation. Furthermore, because the movement limiting protrusions 375a and 375b of the contact stop 345 pair are located at both end portions of the internal gear 374, the orientation of the internal gear 374 can be stable without tilting. This suppresses vibrations and noise caused by the internal gear 374 during operation. Moreover, when the planetary gear meshes at the center of the internal gear 347, vibrations and noise can be suppressed even more by providing stops 345 at both end portions.

[0147] It should be noted that, such as Figure 19 As shown, the stop 345 formed on the second housing 40 is continuously formed over the entire range of the space in which the internal gear 374 does not need to be accommodated. For example, the stop may be provided only at the positions corresponding to the movement limiting protrusions 375a and 375b, with the components in between omitted.

[0148] (Implementation Plan 4)

[0149] In the internal gear 474 according to the fourth embodiment, such as Figure 20 As shown, a plurality of narrow movement-limiting protrusions 475a to 475f (which may be referred to as "movement-limiting protrusions 475", as a general term) are provided at equal intervals from the +X direction side to the -X direction side. The cross-section of the movement-limiting protrusions 475 is triangular. The movement-limiting protrusions 475a are provided at the end portion of the internal gear 474 on the +X axial side. Additionally, the movement-limiting protrusions 475f are provided at the end portion of the internal gear 474 on the -X axial side. When the internal gear 474 is received at the first position 41 in the second housing 40, as... Figure 21 As shown, the movement-limiting protrusion 475 is inserted between the pairs of stops 345. The pairs of stops 345 are continuously formed throughout the space in which the second housing 40 accommodates the internal gear 474, so that the movement-limiting protrusion 475 can be inserted, which is formed at equal intervals from its end portion on the +X side to its end portion on the -X side of the internal gear 474. In this way, the contact between the movement-limiting protrusion 475 and the pairs of stops 345 will be such that the components having line contact between the individual movement-limiting protrusions 475a to 475f and the pairs of stops 345 will be aligned along the X-axis in a straight line with a predetermined spacing between them.

[0150] Thus, the range where the movement limiting protrusions 475 are provided and not provided on the internal gear 474 is alternately arranged. This shortens the total length of the line contact along the X-axis between the movement limiting protrusions 475 and the stop 345. In this way, the contact area between the outer peripheral surface of the internal gear 474 and the inner peripheral surface of the second housing 40 can be further reduced, thereby reducing the transmission of vibrations from the internal gear 474 to the second housing 40 during operation. Furthermore, the internal gear 474 can contact the pair of stops 345 formed on the second housing 40 by a plurality of movement limiting protrusions 475a to 475f arranged at equal intervals, thereby stabilizing the orientation of the internal gear 474 so as not to tilt. This suppresses vibrations and noise caused by the internal gear 374 during operation.

[0151] (Implementation Plan 5)

[0152] In the above embodiments, the contact area is limited to a narrow range through structuring to create line contact between the stop pair and the movement-limiting protrusion in the X-axis direction. However, the direction of the line contact is not limited to the X-axis direction, but can be arbitrarily set. For example, it can be along a direction perpendicular to the X-axis direction, or along a direction between the X-axis direction and the direction perpendicular to the X-axis direction. The form in which line contact is created between the stop pair and the movement-limiting protrusion in a direction perpendicular to the X-axis direction will be interpreted as the fifth embodiment.

[0153] like Figure 22 As shown, with Figure 7 Similar to the internal gear 74 in the first embodiment shown, the internal gear 574 has a movement-limiting protrusion 575 formed over its entire width, the protrusion having a triangular cross-section. However, the cross-sectional dimensions of the triangle of the movement-limiting protrusion 575 are formed to vary depending on its position along the X-axis. This differs from the internal gear 74 in the first embodiment, which has a movement-limiting protrusion 75 with a constant cross-sectional dimension regardless of its position along the X-axis. Figure 22 As shown, the cross-sectional dimension of the movement-restricting protrusion 575 is smallest at the end portion 575a on the +X axial side and the end portion 575b on the -X axial side of the internal gear 574, and gradually increases towards the center along the X axial direction. Therefore, the cross-sectional dimension of the movement-restricting protrusion 575 is largest at the central portion 575c along the X axial direction.

[0154] In addition, such as Figure 10 As shown, in the first embodiment, the outer surface of the stop member 45 pair is a curved surface formed by the upright portion 45a, the connecting portion 45b, and the top 45c. On the other hand, as... Figure 23 As shown, the pair of stops 245a each has a straight, inclined edge portion 245 that stands upright from the inner wall 244a of the cylinder 244. Accordingly, each of the pairs of stops 245 has a triangular cross-section, and the inclined edge portion 245a forms a flat area.

[0155] It should be noted that, Figure 23 and Figure 24 In the diagram, the dashed lines describing the movement-limiting protrusion 575 show the end portions 575a and 575b of the internal gear 574. Figure 22 The cross-section of the movement-limiting protrusion 575 at the point is shown. On the other hand, the solid line shows the central portion 575c of the internal gear 574 in the X-axis direction. Figure 22The cross-section of the movement-restricting protrusion 575 at the center portion 575c of the internal gear 574 is larger than the cross-section of the movement-restricting protrusion 575 at the end portions 575a and 575b of the internal gear 574, as described above. Figure 23 As shown, the internal gear 574 moves upward in a direction perpendicular to the axis, for example, from a state in which the internal gear is not in contact with the second housing 240. In view of this, as... Figure 24 As shown, the movement-limiting protrusion 575 is inserted between the pairs of stops 245, and the plane of the inclined edge portion 245a of the pair of stops 245 will soon contact the inclined edge portion 575d of the movement-limiting protrusion 575. It should be noted that the cross-sectional dimension of the movement-limiting protrusion 575 is largest at the central portion 575c. Figure 22 Therefore, the movement-limiting protrusion 575 contacts the stop 245 at the inclined edge portion 575d in the center portion 575c. Figure 22 ), but except in the central part 575c ( Figure 22 The stop 245 at the inclined edge portion 575d is not in contact with the stop 245 outside of (e.g., at the part indicated by the dashed line). Therefore, the internal gear 574 may only contact the second housing 240 on line L1. Figure 23 ),like Figure 22 As shown. That is, the outer peripheral surface of the internal gear 574 and the inner peripheral surface of the second housing 240 can make line contact along a direction perpendicular to the X-axis. Note that although in Figure 22 The line L1 for centerline contact is shown as being used only for a single movement restriction protrusion 575, but similar line contact along a line perpendicular to the axis can also be made in other movement restriction protrusions 575.

[0156] It should be noted that although the above description pertains to the case where the internal gear 574 moves in a direction perpendicular to the axis, even when contacting the second housing 240 is achieved through rotation about the axis, line contact may occur in the same manner along a direction perpendicular to the X-axis. This limits the contact between the outer peripheral surface of the internal gear 574 and the inner peripheral surface of the second housing 240 to line contact, thereby reducing the transmission of vibrations from the operating internal gear 574 to the second housing 240.

[0157] (Implementation Plan 6)

[0158] Although the above embodiment describes a structure in which the contact between the stop and the movement-limiting protrusion forms a line contact, other contact forms are possible as long as they reduce the contact area. An embodiment in which the contact between the stop and the movement-limiting protrusion is a point contact will be explained below as a sixth embodiment.

[0159] like Figure 25 As shown, the movement-restricting protrusion 675 is formed over the entire width of the internal gear 674. (As indicated...) Figures 25 to 27 As shown, the movement-restricting protrusion 675 has a first position 675a ​​and a convex second position 675b. The first position has a triangular cross-section and extends along the X-axis. The convex second position is disposed on each of the inclined surfaces of the first position 675a. The second position 675b has a square pyramid shape, which is formed by a base 675c that coincides with the rectangular inclined surface of the first position 675a. Figure 26 The position is defined by the top P. Therefore, the position of the second position 675b, which is furthest from the first position 675a, is the top P. Note that the structure of the stop 245 pair is similar to... Figure 23 The structure described above. That is, on the outer surface of the stop 245 pair, the planar area is constructed by the inclined edge portion 245a.

[0160] like Figure 26 As shown, the internal gear 674 moves upward in a direction perpendicular to the axis, for example, from a state in which the internal gear is not in contact with the second housing 240. In view of this, as... Figure 27 As shown, the movement-limiting protrusion 675 is inserted between the pairs of stops 245, and the top P quickly contacts the inclined edge portion 245a of the pairs of stops 245. This type of contact is a point contact made through a plane that forms the inclined edge portion 245a of the pairs of stops 245 and the top P of the second position 675b having a square pyramid shape.

[0161] It should be noted that although the above description pertains to the case where the internal gear 674 moves in a direction perpendicular to the axis, even when contacting the second housing 240 is achieved through rotation about the axis, the top P can still form point contact with the stop 245. In this way, the contact range between the outer peripheral surface of the internal gear 674 and the inner peripheral surface of the second housing 240 can be maintained to a range that can be described as point contact. This reduces vibrations transmitted from the operating internal gear 674 to the second housing 240.

[0162] (Implementation Plan 7)

[0163] In the sixth embodiment, by providing a square pyramidal second position 675b at each of the inclined surfaces of the movement limiting protrusion 675, the structure is used to achieve point contact with the stop 245 at a single point; however, there is no specific limitation on the number of point contacts. The form of achieving point contact with the stop pair at multiple positions on a single inclined surface of the movement limiting protrusion will be explained next.

[0164] like Figure 28As shown, the movement-restricting protrusion 775 is formed over the entire width of the internal gear 774. The movement-restricting protrusion 775 has: a first position 775a having a triangular cross-section extending along the X-axis; and four second positions 775b arranged in a line on each inclined surface of the triangular first position 775a, as shown. Figures 28 to 30 As shown. Each of the second positions 775b forms a truncated cone, which are arranged in a line along the X-axis. Note that the structure of the stop pair 245 is similar to Figure 23 The structure described herein. That is, on the outer surface of the stop 245 pair, the planar region is constructed by the inclined edge portion 245a.

[0165] like Figure 29 As shown, the internal gear 774 moves upward in a direction perpendicular to the axis, for example, from a state in which the internal gear is not in contact with the second housing 240. In view of this, as... Figure 30 As shown, the movement-limiting protrusion 775 is inserted between the pairs of stops 245, and the second position 775b, which is truncated conical in shape, quickly contacts the pairs of stops 245. This type of contact is the contact between the plane of the inclined edge portion 245a forming the pairs of stops 245 and the second position 775b, which is a truncated cone. In this way, the internal gear 774 and the second housing 240 can form point contacts at four positions along the X-axis.

[0166] It should be noted that although the above description pertains to the case where the internal gear 774 moves in a direction perpendicular to the axis, even when contacting the second housing 240 is achieved through rotation about the axis, the conical second position 775b can still form point contact with the stop 245. In this way, the contact range between the outer peripheral surface of the internal gear 774 and the inner peripheral surface of the second housing 240 can be maintained to a range that can be described as point contact. This reduces vibrations transmitted from the operating internal gear 774 to the second housing 240.

[0167] (Modified Implementation Example)

[0168] This invention is not limited to the above-described embodiments, but can be modified and applied in various ways. In the above-described embodiments, the pair of stops 45 is disposed in the second housing 40, and the movement-limiting protrusion 75 inserted between the pair of stops 45 is disposed on the internal gear 74. However, this invention is not limited to this, but the positions of the pair of stops 45 and the movement-limiting protrusion 75 can be switched, such that the movement-limiting protrusion 75 is disposed on the inner peripheral surface of the second housing 40, and the pair of stops 45 is disposed on the outer peripheral surface of the internal gear 74.

[0169] Although the cross-section of the stop pair 45 is herringbone and the cross-section of the movement limiting protrusion 75 is triangular, these cross-sectional shapes can be changed so that the cross-section of the stop pair is triangular and the cross-section of the movement limiting protrusion inserted between the stops is herringbone.

[0170] Furthermore, there is no specific limitation on the number of positions where the 45 pairs of stops and the corresponding movement-limiting protrusions 75 are provided; the number can be a larger number or a smaller number than the six positions given in the above embodiment.

[0171] Furthermore, although in the first embodiment, the movement of the convex surfaces of the stop 45 is caused to restrict the plane of the protrusion 75 to result in line contact therebetween, line contact can also be achieved by causing contact of other shapes. Reference will be made next. Figure 31 This describes another implementation scheme for achieving line contact. (Compared to...) Figure 9 The difference in the structure shown in the enlarged view is that the cross-section of the movement-restricting protrusion (first protrusion) 175 is not triangular, but rather a rounded herringbone shape. Note that the structure of the second housing 40 is different from... Figure 9 The structure shown in the magnified view is the same. Figure 31 In the diagram, when the actuator is not in operation, the internal gear 174 is indicated by a solid line. Furthermore, the internal gear 174, shown by a double-dotted dashed line, is in a state where it has moved upwards to contact the second housing 40 due to the operation of the actuator. Figure 31 As shown, the contact between the stop pair 45 and the movement limiting protrusion 175 is a contact between convex surfaces, therefore, the contact points P6 and P7 between the stop pair 45 and the movement limiting protrusion 175 will be line contacts. Thus, in this embodiment, line contact is achieved by causing the bulging convex surfaces to contact each other.

[0172] Furthermore, there are no limitations on this, where line contact can be achieved through a second housing 40 with a locally concave component of high curvature and an internal gear 74 with a convex surface of lower curvature, wherein the concave surface with high curvature contacts the bulging convex surface. The actual structure used to achieve line contact is arbitrary.

[0173] It should be noted that in another example used to achieve the above-mentioned line contact, the configuration of the internal gear in the position of making line contact can be interchanged with the configuration of the second housing.

[0174] Furthermore, although the actuator 1 is provided with a two-stage planetary gear mechanism consisting of a first planetary gear mechanism 70 and a second planetary gear mechanism 80, the number of stages can be arbitrarily set as a speed reduction mechanism for reducing the rotation of the motor 10. For example, the reduction ratio can be increased by providing a three-stage or more planetary gear mechanism, or the structure may include only a single-stage planetary gear mechanism.

[0175] Furthermore, in the above embodiments, a configuration is used in which the housing and internal gear separation structure is applied only to the first planetary gear mechanism 70, which is a first-stage mechanism rotating at high speed, and the housing with internal teeth formed on its inner peripheral surface is used in the second planetary gear mechanism 80, which is a second-stage mechanism rotating at low speed. However, the housing and internal gear separation structure can also be used in the second planetary gear mechanism 80 as a second-stage mechanism to reduce vibration and noise.

[0176] Furthermore, although the above embodiment is described in relation to the case where the reduction gear is used to reduce the rotation input from the motor 10 and output it from the output gear 86a, this application is not limited thereto. For example, Figure 8 The component shown, equipped with an output shaft 86, can be used as an input side and connected to the rotating shaft of the motor. Figure 7 The component shown, equipped with the sun gear 71, can be used as the output side and is connected to the output shaft. This increases and outputs the rotation of the motor, serving as a speed-increasing mechanism. In this case, due to... Figure 7 The high-speed operation of the first planetary gear mechanism 70 shown is also preferably achieved using a structure in which the internal gear and housing are separated. Furthermore, since the rotation of the motor is directly transmitted to… Figure 8 The second planetary gear mechanism 80 shown is therefore preferably configured such that the internal gear and housing are separated, as needed. Furthermore, the invention can also be applied to industrial equipment such as robots and machine tools, as well as to amusement park equipment such as so-called "tumbler machines".

[0177] When this invention is used in various applications, when the planetary gear mechanism is provided in three or more stages, a structural unit for separating the internal gear and the housing is applied to the planetary gear mechanism operating at the highest speed. This effectively reduces the resulting vibration and noise. Furthermore, since the vibration and noise generated by the planetary gear mechanism operating at the lowest speed are minimal, a structure equipped with a housing in which the internal teeth are formed on the inner peripheral surface is applied. This eliminates the need for an unnecessary structure for separating the internal gear and the housing, thereby avoiding an increase in the number of parts and an increase in assembly operations and costs, and thus suppressing production costs.

[0178] Furthermore, although the embodiments described above are for the case where each gear in the gears used to transmit power from motor 10 to output shaft 86 is a helical gear, other gears may be used instead. For example, spur gears may be used. Although spur gears tend to produce a larger clearance at the meshing position compared to the case of using helical gears, the structure of the present invention can still be used to reduce (suppress) vibration and noise of the planetary gear unit even in this case.

[0179] Furthermore, although the description pertains to a case where the separate structural unit for the internal gear and the housing is used as part of a planetary gear mechanism, this application is not limited to this, but can be used as part of another gear mechanism.

[0180] In the above embodiments, the planetary gear mechanism of the planetary gear device is implemented using three planetary gears; however, the present invention is not limited thereto. In the present invention, the planetary gear device can be implemented by using a planetary gear mechanism having, for example, a single planetary gear or multiple (other than three) planetary gears.

[0181] Furthermore, the planetary gear device of the present invention can be applied to a variety of machines and equipment that use speed reduction or speed increase mechanisms, such as automobiles, robots, industrial equipment, amusement park equipment, etc.

[0182] Furthermore, although in the second embodiment, the movement-limiting protrusions 275 are formed on the +X axial side of the internal gear 274, they can alternatively be formed on the -X axial side. In this case, the pair of stops 45 formed on the second housing 40 extends to the -X axial side, such that the movement-limiting protrusions formed on the -X axial side will be inserted between the pair of stops.

[0183] In addition, Figure 20 In the internal gear 474 shown according to the fourth embodiment, the movement limiting protrusions 475 are arranged at equal intervals. However, the distance between adjacent movement limiting protrusions 475 can be arbitrarily varied, and the movement limiting protrusions 475 may be arranged at different intervals. Furthermore, six movement limiting protrusions 475 are arranged along the X-axis on the internal gear 474. However, the number of movement limiting protrusions 475 formed along the X-axis can be arbitrarily determined.

[0184] In addition, Figures 16 to 21 In embodiments 2 to 4 shown, the width of the movement-limiting protrusions formed on the internal gear in the X-axis is narrow, or multiple movement-limiting protrusions are arranged at equal intervals along the X-axis to result in continuous contact with the stop pair in the X-axis. However, this correspondence can be reversed, wherein the movement-limiting protrusions are continuous in the X-axis, and the width of the stop pair in the X-axis can be reduced, or it can be divided into multiple stops and arranged at equal intervals in the X-axis.

[0185] Furthermore, despite Figure 25 In the internal gear 674 shown according to the sixth embodiment, the top P is positioned at the center of the inclined surface of the first position 675a, but the position of the top P can be arbitrarily changed by changing the shape of the square pyramid.

[0186] In addition, although Figure 28 In the internal gear 774 according to the seventh embodiment shown, the second positions 775b of the truncated cone are arranged in a line along the X-axis, but the arrangement of the second positions 775b can be arbitrarily determined. For example, the second positions can be arranged horizontally and vertically in a grid shape, or they can form a zigzag pattern.

[0187] In addition, Figures 22 to 30 In embodiments 5 to 7 shown, features are added to enable line or point contact between the stop pair and the movement-limiting protrusion of the internal gear. However, these features can alternatively be provided on the stop pair. For example, as Figure 22 As shown, the structure in the fifth embodiment, where the cross-sectional dimension of the movement-limiting protrusion varies along the X-axis, can be applied to a pair of stops, wherein the cross-section of the stop varies along the X-axis to a maximum value at the center. In the sixth embodiment, corresponding to having Figure 25 The structure of the second position 675b, which is a square pyramid shape as shown, can alternatively be formed in the stop pair. In the seventh embodiment, corresponding to Figure 28 The structure shown for the second position 775b of the truncated cone can alternatively be formed for the stop pair.

[0188] Explanation of the voting process (see attached diagram)

[0189] 1: Actuator

[0190] 10: Motor

[0191] 11: Motor main unit

[0192] 12: Rotation axis

[0193] 20: Planetary gear mechanism

[0194] 30: First shell

[0195] 30a: Open

[0196] 40: Second shell

[0197] 41: First position

[0198] 42: Second position

[0199] 43: Third position

[0200] 43a: Opening

[0201] 44: Cylinder

[0202] 44a: Inner wall

[0203] 45: Stop (second protruding part)

[0204] 45a: Upright part

[0205] 45b: Connection part

[0206] 45c: Top

[0207] 46: Cylinder

[0208] 47: Internal teeth section

[0209] 50: Casing

[0210] 60: Planetary gear mechanism

[0211] 70: First planetary gear mechanism

[0212] 71: Sun Gear

[0213] 71a: Sun tooth portion

[0214] 72: Planetary Gears

[0215] 72a: Planetary tooth section

[0216] 73: Stent

[0217] 73a: Accommodation opening

[0218] 74: Internal gear

[0219] 74a: Internal teeth section

[0220] 74b: Outer peripheral surface

[0221] 75: Movement restriction protrusion (first protrusion)

[0222] 75a: Sloping edge portion

[0223] 75b: Top

[0224] 75c: Notch portion

[0225] 76: Sales

[0226] 80: Second planetary gear mechanism

[0227] 81: Sun Gear

[0228] 81a: Sun tooth portion

[0229] 82: Planetary Gear

[0230] 82a: Planetary tooth section

[0231] 83: Bracket

[0232] 84: Gear retaining part

[0233] 84a: Accommodation opening

[0234] 85: Output shaft holding section

[0235] 85a: Assembly hole

[0236] 86: Output shaft

[0237] 86a: Output gear

[0238] 87: Sales

[0239] 90: Contact Area

[0240] 140: Second shell

[0241] 141: Concave component

[0242] 174: Internal gear

[0243] 175: Movement restriction protrusion (first protrusion)

[0244] 240: Second shell

[0245] 244: Cylinder

[0246] 245: Stop

[0247] 245a: Sloping edge portion

[0248] 274: Internal gear

[0249] 275: Movement restriction protrusion

[0250] 345: Stop

[0251] 374: Internal gear

[0252] 375a, b: Movement restriction protrusions

[0253] 474: Internal gear

[0254] 475: Movement restriction protrusion

[0255] 574: Internal gear

[0256] 575: Movement restriction protrusion

[0257] 674: Internal gear

[0258] 675: Movement restriction protrusion

[0259] 774: Internal gear

[0260] 775: Movement restriction protrusion

Claims

1. A device for suppressing noise generated in a planetary gear mechanism, characterized in that, The device includes: An internal gear having a first protrusion formed on the outer peripheral surface of the internal gear, the first protrusion extending axially from one side of the internal gear to the other side; and A housing having a second protrusion formed on an inner peripheral surface of the housing, wherein the housing is configured to receive the internal gear such that a gap exists between the inner peripheral surface of the housing and the outer peripheral surface of the internal gear, wherein: The movement of the internal gear within the housing is restricted by two independent line contacts between the first and second protrusions. One of the first and second protruding portions forms a pair of protrusions spaced apart, while the other protrusion is positioned to be inserted between the pair of protrusions. The surface on one of the first and second protruding portions that contacts the surface on the other of the first and second protruding portions is curved.

2. The device according to claim 1, characterized in that: The second protrusions are formed in pairs, and there is a gap between the pairs of second protrusions; and When cut by a plane perpendicular to the axis, the first protrusion has a triangular cross-section, and the first protrusion contacts the second protrusion at an inclined surface formed in the plane.

3. The device according to claim 1, characterized in that: The surface of one of the first and second protruding portions that contacts the surface of the other protruding portion is a convex curved surface, and the surface of the other protruding portion that contacts the surface is a plane.

4. The device according to claim 1, characterized in that: A portion of the first protrusion and a portion of the second protrusion that are in contact with each other are convex surfaces.

5. The device according to claim 1, characterized in that: The surface of one of the first and second protruding portions that contacts the surface of the other protruding portion is a convex curved surface, and the surface of the other protruding portion that contacts the surface is also a convex curved surface.

6. The device according to any one of claims 1 to 5, characterized in that: The first protrusion and the second protrusion are in contact along the axial line; and The length of the line contact between the first protrusion and the second protrusion is less than the axial width of the internal gear.

7. The device according to any one of claims 1 to 5, characterized in that: The length of the first protrusion on the internal gear is less than the width of the internal gear in the axial direction.

8. The device according to claim 7, characterized in that: The first protrusion extends only from one end of the internal gear.

9. The device according to claim 7, characterized in that: The first protrusion extends from both ends of the internal gear; and The total length of the first protrusions extending from both ends is less than the axial width of the internal gear.

10. The device according to any one of claims 1 to 5, characterized in that: The internal gear has a plurality of first protrusions spaced apart from each other along the axial direction.

11. The device according to any one of claims 1 to 5, characterized in that: The movement of the internal gear within the housing is restricted by the line contact between the first protrusion and the second protrusion in a direction perpendicular to the axial direction.

12. The device according to claim 11, characterized in that: When cut by a plane perpendicular to the axial direction, one of the first and second protruding portions has a triangular cross-section, wherein the dimensions of the triangular cross-section vary depending on its position along the axial direction. The contact between the first protrusion and the second protrusion is located at the position where the cross-sectional dimension of the triangle is the largest.

13. A device for suppressing noise generated in a planetary gear mechanism, characterized in that, The device includes: An internal gear having a first protrusion formed on the outer peripheral surface of the internal gear; A housing having a second protrusion formed on an inner peripheral surface, wherein the housing is configured to receive the internal gear such that a gap is provided between the inner peripheral surface and the outer peripheral surface. One of the first protruding portion and the second protruding portion forms a pair of protrusions spaced apart, while the other protruding portion of the first protruding portion and the second protruding portion is configured to be inserted between the pair of protrusions. The surface on one of the first and second protruding portions that contacts the surface on the other of the first and second protruding portions is curved, and The movement of the internal gear within the housing is restricted by two independent point contacts between the first and second protrusions.

14. The device according to claim 13, characterized in that: The first protrusion is formed to extend axially from one side of the internal gear to the other side of the internal gear, and the second protrusion is formed to extend axially from one side of the housing to the other side of the housing.

15. The device according to claim 14, characterized in that: A protrusion is formed on the first protrusion or the second protrusion at the contact position between the first protrusion and the second protrusion, and the first protrusion and the second protrusion make point contact through the protrusion.

16. The device according to claim 15, characterized in that: Multiple of the protrusions are formed along the axial direction.

17. The device according to any one of claims 15 or 16, characterized in that: When cut by a plane perpendicular to the axis, the first protrusion has a triangular cross-section, and the protrusion is formed on an inclined surface forming the plane.

18. The device according to any one of claims 1 to 5 and 13 to 16, characterized in that: The internal gear and the housing are made of synthetic resin; and The internal gear is formed of a synthetic resin with a lower hardness than the synthetic resin used to form the housing.

19. A planetary gear mechanism, characterized in that, The device includes: Device for suppressing noise generated in a planetary gear assembly according to any one of claims 1 to 5 and 13 to 16; One or more planetary gears, which mesh with the internal gear; A sun gear, which meshes with one or more planetary gears and is positioned at the center of the one or more planetary gears; and A bracket that can rotatably support the one or more planetary gears.

20. The planetary gear device according to claim 19, characterized in that, The device further includes: The second sun gear rotates together with the bracket; One or more second planetary gears are disposed on the periphery of the second sun gear and mesh with the second sun gear; A second support, which rotatably supports one or more second planetary gears; and A second housing has internal teeth formed on its inner peripheral surface and meshes with the one or more second planetary gears, wherein the housing and the second housing are integrally formed.

21. A planetary gear mechanism, characterized in that, The device includes: At least two stages of planetary gear mechanisms, each stage of which includes: Sun gear; One or more planetary gears, the one or more planetary gears being arranged on the periphery of the sun gear for meshing with the sun gear; and A bracket, which rotatably supports the one or more planetary gears. In the at least two-stage planetary gear mechanism, the planetary gear mechanism operating at the highest speed includes a device for suppressing noise generated in the planetary gear assembly according to any one of claims 1 to 5 and 13 to 16, wherein the one or more planetary gears of the planetary gear mechanism mesh with the internal gear; and In the at least two-stage planetary gear mechanism, the planetary gear mechanism operating at the lowest speed includes a housing having internal teeth formed on its inner peripheral surface, and the internal teeth meshing with one or more planetary gears of the planetary gear mechanism.

22. An actuator, characterized in that, The actuator includes: The planetary gear assembly according to claim 19; and A motor connected to the planetary gear assembly for driving the planetary gear assembly.

23. An actuator, characterized in that, The actuator includes: The planetary gear assembly according to claim 20; and A motor connected to the planetary gear assembly for driving the planetary gear assembly.

24. An actuator, characterized in that, The actuator includes: The planetary gear assembly according to claim 21; and A motor connected to the planetary gear assembly for driving the planetary gear assembly.

Images