Gear housing for a planetary gear device structurally separating the ring gear

Abstract

The present application provides an apparatus for suppressing noise generated in a planetary gear device, a planetary gear device, and an actuator. The apparatus for suppressing noise generated in a planetary gear device includes an inner gear having a first contact portion formed on an end surface of the inner gear on one side in an axial direction, and a housing for accommodating the inner gear, the housing having a second contact portion for restricting movement of the inner gear by contacting the first contact portion formed on the inner gear.

Description

Technical Field

[0001] The present invention relates to a separate structural unit for an internal gear and a housing, a planetary gear assembly including the separate structural unit, and an actuator including the 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] [Prior Art References]

[0005] [Patent Documents]

[0006] [Patent Document 1] Japanese Unexamined Patent Application Publication H6-74835 Summary of the Invention

[0007] The problem solved by this invention

[0008] 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.

[0009] 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.

[0010] Problem Solving Methods

[0011] According to the present invention, an apparatus for suppressing noise generated in a planetary gear assembly includes: an internal gear having a first contact portion formed on an end face of the internal gear on an axially upward side; and a housing for receiving the internal gear, the housing having a second contact portion for restricting movement of the internal gear by contacting the first contact portion formed on the internal gear.

[0012] In some embodiments, the internal gear is housed within the housing such that a gap is formed between the inner peripheral surface of the housing and the internal gear.

[0013] In some embodiments, one of the first contact portion and the second contact portion is a protrusion formed along the axial direction, and the other contact portion of the first contact portion and the second contact portion is a recessed portion into which the protrusion is inserted.

[0014] In some embodiments, the protrusion is a post, and the movement of the internal gear in a direction perpendicular to the axial direction is restricted by line contact between the side of the post and the sidewall portion of the recessed portion.

[0015] In some embodiments, the tip portion of the protrusion is formed as a hemispherical shape, and the movement of the internal gear in the axial direction is restricted by the contact between the tip portion and the bottom surface of the recessed portion.

[0016] In some embodiments, one of the first contact portion and the second contact portion includes a plurality of paired protrusions spaced apart from each other, and the protrusions are spaced apart in a circumferential direction, and the other contact portion includes a plurality of protrusions formed to be inserted between the paired protrusions and spaced apart in the circumferential direction.

[0017] In some embodiments, the first contact portion and the second contact portion are in line contact.

[0018] In some embodiments, the housing includes a first housing having an open portion on one side in the axial direction, wherein the housing includes a second housing attached to the first housing to block the open portion, and wherein a second contact portion is formed on the second housing.

[0019] According to the present invention, a planetary gear device includes: the aforementioned device for suppressing noise generated in the planetary gear device; 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.

[0020] An actuator according to the present invention includes: the planetary gear assembly; and a motor connected to the planetary gear assembly for driving the planetary gear assembly.

[0021] The structural unit for separating the internal gear and the housing includes: an internal gear, wherein a first contact portion is formed axially on an end face on one side; and a housing for receiving the internal gear, wherein a second contact portion is formed, the second contact portion being used to restrict the movement of the internal gear by contacting the first contact portion formed on the internal gear, thereby allowing the gear to move.

[0022] The internal gear can be accommodated within the first housing with a gap provided from the inner peripheral surface of the first housing.

[0023] In the first contact portion and the second contact portion, one contact portion may be a protrusion formed along the axial direction, and the other contact portion may be a recessed portion into which the protrusion is inserted.

[0024] The protrusion may have a post, and the movement of the internal gear in a direction perpendicular to the axial direction may be restricted by the line contact between the side of the post and the sidewall portion of the recess.

[0025] The tip portion of the protrusion may be formed in a hemispherical shape; and the movement of the internal gear in the axial direction may be restricted by the contact between the tip portion and the bottom surface of the recess.

[0026] In the first contact portion and the second contact portion, one contact portion may be a pair of protrusions formed to have a space between them, and may be arranged with a plurality of protrusions in the circumferential direction, wherein the other contact portion may be a protrusion formed to insert between the pair of said one contact portion, and may be provided with a plurality of protrusions in the circumferential direction.

[0027] The first contact portion and the second contact portion can make line contact.

[0028] The aforementioned housing may have a first housing and a second housing, the first housing having an open portion on one side in the axial direction, and the second housing being attached to the first housing to block the open portion; and the second contact portion may be formed on the second housing.

[0029] 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.

[0030] 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.

[0031] Effects of the present invention

[0032] 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.

[0033] 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 accompanied by the vibrations of the planetary gear mechanism.

[0034] A structural unit for separating an internal gear and a housing includes: an internal gear, wherein a first contact portion is formed axially on an end face on one side; and a housing for receiving the internal gear, having a second contact portion for restricting movement of the internal gear by contacting the first contact portion formed on the internal gear, thereby allowing movement. In the first and second contact portions, one contact portion is a protrusion formed axially, and the other contact portion is a recess into which the protrusion is inserted. Attached Figure Description

[0035] Figure 1 This is a perspective view of the actuator based on the reference example.

[0036] Figure 2 From Figure 1 Arrow AII in the diagram shows the front view of the actuator.

[0037] Figure 3In order to be in Figure 2 The cross-sectional view of the actuator taken from section line III-III in the diagram.

[0038] Figure 4 This is an assembly perspective view of the actuator based on the reference example.

[0039] Figure 5 It is a cross-sectional view of the first housing based on the reference example.

[0040] Figure 6 This is a perspective view of the first housing based on the reference example.

[0041] Figure 7 This is a perspective view of the first planetary gear mechanism based on the reference example.

[0042] Figure 8 This is a perspective view of the second planetary gear mechanism based on the reference example.

[0043] Figure 9 This is a diagram used to illustrate the relationship between the first housing and the internal gear according to the reference example.

[0044] Figure 10 To focus on the formation of Figure 9 An illustrative diagram of the stop in the first housing shown.

[0045] Figure 11 To focus on the formation of Figure 9 An illustrative diagram of the movement-limiting protrusion on the internal gear shown.

[0046] 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 first housing.

[0047] 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 first housing.

[0048] Figure 14 For the purpose of illustrating when from Figure 12 The arrow XIV in the diagram is an illustrative illustration of the contact state between the first housing and the internal gear when observed.

[0049] Figure 15 To be Figure 11 The diagram shown compares the movement restriction protrusion with another example of a movement restriction protrusion.

[0050] Figure 16 This is a perspective view of an internal gear according to a first embodiment of the present invention.

[0051] Figure 17 To show Figure 16 The diagram shows an internal gear, where (a) is the gear when... Figure 16 (a) is the view observed by arrow XVII in (b), and (b) is the cross-sectional view taken using section BB in (a).

[0052] Figure 18 This is a perspective view of the second housing according to a first embodiment of the present invention.

[0053] Figure 19 To show Figure 18 The diagram shows the second housing, where (a) is the first housing when... Figure 18 (a) is a view taken with arrow XIX in (b), and (b) is a cross-sectional view taken using section BB in (a).

[0054] Figure 20 A cross-sectional view showing the state in which the second housing and the internal gear according to the first embodiment of the present invention are attached to the first housing.

[0055] Figure 21 To illustrate that the internal gear has been removed Figure 19 (a) is a diagram of the state of rotation around the axis.

[0056] Figure 22 To illustrate that the internal gear has been removed Figure 19 (a) is a diagram of the state in which the state moves in a direction perpendicular to the axis.

[0057] Figure 23 To illustrate a schematic diagram of an internal gear according to a second embodiment of the present invention, (a) is a view when viewed from the -X direction side, and (b) is a cross-sectional view taken using section BB in (a).

[0058] Figure 24 To illustrate a schematic diagram of the second housing according to a second embodiment of the present invention, wherein (a) is a view when viewed from the +X direction side, and (b) is a cross-sectional view taken using section BB in (a).

[0059] Figure 25 This is a cross-sectional view of an internal gear according to a third embodiment of the present invention.

[0060] Figure 26 In order to be in Figure 25 The cross-sectional view of the internal gear taken from section line XXVI-XXVI in the diagram.

[0061] Figure 27 To illustrate that the internal gear has been removed Figure 26 The diagram shows the state of rotation around the axis.

[0062] Figure 28 To illustrate that the internal gear has been removed Figure 26 The diagram shows the state of rotation around the axis.

[0063] Figure 29 This is a perspective view of an internal gear according to a fourth embodiment of the present invention.

[0064] Figure 30 This is a perspective view of the first housing according to a fourth embodiment of the present invention.

[0065] Figure 31 From Figure 30 The arrow XXXI in the diagram shows a plan view of the first shell.

[0066] Figure 32 A diagram illustrating the state in which the internal gear is housed in the first housing according to a fourth embodiment of the present invention.

[0067] Figure 33 This is a view of the second housing according to the fifth embodiment of the present invention from the +X direction side.

[0068] Figure 34 To illustrate a schematic diagram of an internal gear according to a sixth embodiment of the present invention, wherein (a) is a view when viewed from the -X direction side, and (b) is a cross-sectional view taken using section BB in (a).

[0069] Figure 35 To illustrate a schematic diagram of the second housing according to the sixth embodiment of the present invention, wherein (a) is a view when viewed from the +X direction side, and (b) is a cross-sectional view taken using section BB in (a).

[0070] Figure 36 A cross-sectional view showing the state in which the internal gear is attached to the second housing according to a sixth embodiment of the present invention.

[0071] Figure 37 In order to be in Figure 36 A cross-sectional view of the internal gear taken from section line XXXVII-XXXVII in the diagram.

[0072] Figure 38 An illustrative diagram is provided to focus on the contact position between the internal gear and the first housing according to another embodiment of the present invention. Detailed Implementation

[0073] 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.

[0074] (Refer to the example)

[0075] (Structure of Actuator 1)

[0076] 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.

[0077] 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.

[0078] 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 second housing 30 and a first housing 40, as... Figure 3 and Figure 4 As shown.

[0079] The second housing 30 is a component used, for example, to attach the motor 10 to the planetary gear mechanism 20. Furthermore, the second housing 30 is assembled with the first housing 40 to form a receiving space S for accommodating the planetary gear mechanism 60, such as... Figure 5 As shown. The second housing 30 covers the opening on the -X direction side of the receiving space S, thereby preventing the planetary gear mechanism 60 from exiting the receiving space. Figure 4 As shown, an opening 30a is formed at the center of the second 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 second housing 30 is formed by injection molding and is made of, for example, synthetic resin.

[0080] The first housing 40 is open on the side ("side") that connects to the second housing 30, for example, as Figure 5 and Figure 6 As shown, and Figure 4The 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 first housing 40 has a first position 41 in which a first planetary gear mechanism 70 is accommodated, a second position 42 in which a 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.

[0081] For example, such as Figure 5 and Figure 6 As shown, the first position 41 of the first 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 size are constant in the axial direction. The stop 45 is formed axially within a portion of the first position 41, but may alternatively 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 first housing 40.

[0082] For example, such as Figure 5 and Figure 6 As shown, the second position 42 of the first 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.

[0083] The third position 43 of the first 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 first housing 40 is formed by injection molding and is made of, for example, synthetic resin.

[0084] Additionally, for convenience in this instruction manual, Figures 4 to 6 In this design, the side of the first housing 40 that is open for attachment to the second housing 30 is referred to as "one side" (-X direction side), and the side of the first 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 first 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 first housing 40 that is open for attachment to the second housing 30 may be referred to and interpreted as the other side.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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 first housing 40, is formed on the outer peripheral surface of the internal gear 74. 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 size of the movement-restricting protrusion 75 are constant in the axial direction (having a constant axial extension from one side to the other), and thus the inclined edge portion 75a of the movement-restricting protrusion 75 forms 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.

[0092] In addition, such as Figure 7 As shown, a hemispherical protrusion 74c is formed on the end face of the internal gear 74 on the +X direction side. The hemispherical protrusion 74c 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 first housing 40, as... Figure 5 As shown, the tops of the six protrusions 74c 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 first housing 40. Considering that the contact between a spherical surface and a plane is a point contact, the contact between the protrusion 74c and the stepped surface 46a is also a point contact. On the other hand, as... Figure 2 As shown, the end face of the internal gear 74 in the -X direction direction is constructed with a flat surface. 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 first housing 40 shown is formed of a synthetic resin with low hardness.

[0093] like Figure 9 As shown, the first housing 40 and the internal gear 74 are physically separated, and a gap exists between the first gear and the internal gear when the actuator 1 is not operated. Therefore, the internal gear 74 is in a floating state within the first housing 40, allowing rotation about the axial direction and allowing movement within the first housing 40 in a direction perpendicular to the axial direction by an amount corresponding to the gap between the internal gear 74 and the first 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 with the movement protrusion 75.

[0094] 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 obscured by the bracket 83.

[0095] 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 their 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.

[0096] 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, planetary gears 82 mesh with internal tooth portions 47 formed on the first housing 40, such as... Figure 5 and Figure 6 As shown.

[0097] 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 first 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 central portion of the output shaft holding portion 85.

[0098] 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.

[0099] (Operation of Actuator 1)

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] As described above, the first housing 40 and the internal gear 74 are physically separated. Furthermore, when the actuator 1 is not operated, a gap is formed between the first 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 first 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 first 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.

[0106] 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 internal gear 74 in the upper part of the figure makes line contact with the stop 45 formed on the first 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 first housing 40 (or more specifically, the inner wall 44a of the cylinder 44). It should be noted that when the internal gear 74 moves upward, the restriction on the movement of the internal gear 74 in the direction perpendicular to the axis is not restricted. 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 internal gear 74 in various directions (e.g., Figure 9 Movement in the vertical, horizontal and diagonal directions.

[0107] (Effect)

[0108] In view of the above reference example, even in a structural unit in which the internal gear 74 and the first 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 first housing 40 as the internal gear 74 rotates about its axis. In this case, the stop 45 and the movement-limiting protrusion 75 make contact in all six positions, and the form of contact is the same for all positions. Therefore, a single contact position at the top of the figure will be illustrated with reference to the enlarged view in Figure 12. As shown, the contact position 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 first 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 first 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.

[0109] also, Figure 13 The diagram illustrates the contact state between the first 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 first 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.

[0110] 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 first 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 first housing 40 is small (in this way, line contact), the vibration transmitted from the internal gear 74 to the first housing 40 during operation will be reduced. This suppresses the vibration of the first 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.

[0111] 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 does not merely indicate a contact state that will be shown only by a single point as a contact point in each individual cross-section, but rather as... 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.

[0112] Furthermore, a hemispherical protrusion 74c is formed on the end face of the internal gear 74 on the +X direction side, where the protrusion 74c contacts the stepped surface 46a of the first housing 40. Figure 5 and Figure 6 The contact between the protrusion 74c and the stepped surface 46a can be maintained within a limited range, i.e., point contact. This reduces vibrations transmitted from the internal gear 74 during operation to the first housing 40.

[0113] 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.

[0114] 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, with both sides 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. Therefore, the proposed reference example 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 above-described reference example can reduce (suppress) the impact when the internal gear 74 contacts the first housing 40, thereby also reducing (suppressing) the vibration of the first housing.

[0115] Furthermore, the internal gear 74 is formed of a synthetic resin with a lower hardness than the synthetic resin used to form the first 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 first 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.

[0116] The synthetic resins used to form the internal gear 74 and the first housing 40 may be the same material or different materials. They may be appropriately selected within the range that produces the effects of the present invention.

[0117] Among the aforementioned synthetic resins, the relatively soft synthetic resin suitable for forming the internal gear 74 preferably uses, 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 first housing 40 preferably uses, 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 first housing 40, preferably, by changing, for example, the density of the synthetic resin, the synthetic resin used to form the first housing 40 will be harder.

[0118] By forming the internal gear 74 from a synthetic resin with a hardness lower than that of the first housing 40, the reference example mitigates impact when the internal gear 74 contacts the first housing 40, thereby reducing (suppressing) vibrations generated within the first housing 40. In this way, the reference example reduces (suppresses) noise caused by vibrations of the first housing 40, and further reduces (suppresses) noise when the internal gear 74 collides with the first 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.

[0119] Furthermore, in the reference example, the structure where the housing and internal gear are separated is applied only to the first planetary gear mechanism rotating at high speed, and not to the second-stage planetary gear mechanism rotating at low speed. That is, in the reference example, the structure that makes the internal gear 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, the reference example 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.

[0120] The embodiments according to the present invention will now be described, but many features are identical to those in the above-described reference examples. Therefore, the description of the following embodiments will focus on the different features, and those identical features in the drawings will be assigned the same reference numerals, and their detailed descriptions will be omitted.

[0121] (Implementation Plan 1)

[0122] Although in the above-described reference example, the protrusions formed on the outer peripheral surface of the internal gear 74 and the protrusions formed on the inner peripheral surface of the first housing 40 are made to contact each other to restrict the movement of the internal gear 74, the position where the contact is made can be arbitrarily set, and there is no limitation on the reference example of the above arrangement. In the first embodiment of the invention, the movement of the internal gear is restricted by causing the protrusions formed on the end face of the internal gear to contact the recesses formed in the second housing.

[0123] like Figure 16 As shown, the outer peripheral surface 274a of the internal gear 274 according to this embodiment is not formed in the movement-restricting protrusion 75 illustrated in the reference example. Figure 7 Instead, it is constructed of a curved surface, in which no recessed or protruding portions are formed. Therefore, in this embodiment, it has been arranged to correspond to the movement-restricting protrusion. Figure 6 The pair of stoppers 45 shown can be omitted. In this way, the internal gear 274 is housed within the first housing 40 with a clearance from the inner peripheral surface of the first housing 40.

[0124] and Figure 7 Similar to the internal gear 74 shown, six hemispherical protrusions 74c are formed on the end face 274b on the +X direction side of the internal gear 274. As shown... Figure 20 As shown, the top of the hemispherical protrusion 74c makes point contact with the stepped surface 46a, which forms the boundary between the first position 41 and the second position 42 of the first housing 40. On the other hand, as... Figure 17 As shown, four protrusions 275 are arranged at equal angular intervals on the end face 274c of the internal gear 274 on the -X direction side. Figure 17 As shown in (b), four protrusions 275 protrude from the end face 274c by a height h1. The protrusions 275 have a shape in which a hemispherical body is connected to the end face of a cylindrical column, thereby fixing a height h1 greater than the radius of the hemispherical body.

[0125] like Figure 18 As shown, with the first housing 40 ( Figure 20 The second housing 230, assembled according to this embodiment, has an opening 230a formed at its center, and the rotating shaft 12 of the motor 10 ( Figure 4 The material is inserted into the opening. The end face 230B on the +X axial side of the second housing 230 is formed as an annular ring, and has four recessed portions 231 formed radially from its center (the position of the axis). The recessed portions 231 formed adjacent to each other in the circumferential direction are perpendicular to each other. That is, the four recessed portions 231 are overlapping grooves forming a "+", which has an intersection point coinciding with the center (position of the axis) of the second housing 230.

[0126] like Figure 18 As shown, the dimensions of the recessed portion 231 are a width of w1 and a depth of d1. Here, the depth d1 of the recessed portion 231 is shallower than w1. Figure 17 The height h1 of the protrusion 275 shown. Furthermore, the width w1 of the recessed portion 231 is wider than... Figure 17 The diameter of the protrusion 275 shown. For example, the width w1 of the recess 231 is approximately 1.2 times the diameter of the protrusion 275. Figure 20As shown, with the four protrusions 275 inserted into their corresponding recesses 231, the internal gear 274 is housed within a housing comprised of the second housing 230 and the first housing 40. Because the width w1 of the recess 231 is wider than the diameter of the protrusions 275, a gap is formed around the protrusions 275 inserted into the recesses 231, as shown... Figure 19 As shown in (a).

[0127] With the internal gear 274 housed within the housing, when the internal gear moves to the +X direction side, then as follows: Figure 20 As shown, the top of the protrusion 74c formed on the internal gear 274 makes point contact with the stepped surface 46a of the first housing 40 to prevent further movement of the internal gear 274. Thus, when the internal gear 274 moves to the +X direction side, the contact between the protrusion 74c and the stepped surface 46a restricts the movement of the internal gear 274 to the +X direction side, and this contact has a narrow range that can be described as a point contact.

[0128] On the other hand, with the internal gear 274 housed within the housing, when the internal gear moves to the -X direction side, then as... Figure 19 As shown in (b), the top of the protrusion 275 formed on the internal gear 274 contacts the bottom surface 231a of the recessed portion 231 formed in the second housing 230. The movement of the internal gear 274 to the -X axial direction is thus restricted. As described above, because the tip of the protrusion 275 is hemispherical, the contact between the top of the protrusion 275 and the bottom surface 231A of the recessed portion 231 will be a point contact. Furthermore, because the depth d1 of the recessed portion 231 ( Figure 18 Shallower than the height h1 of the protrusion 275 ( Figure 17 (b) Therefore, when the top of the protrusion 275 is in contact with the bottom surface 231a of the recess 231, the end face 230b of the second housing 230 can remain away from the end face 274c of the internal gear 274. In this way, the internal gear 274, which has moved to the -X direction side, is prevented from moving towards the -X direction side of the internal gear 274 only through the contact between the protrusion 275 and the bottom surface 231a of the recess 231 (which is within a narrow range that can be called point contact).

[0129] Thus, although the internal gear 274 moves axially, the movement is limited by contact within a narrow range, which can be described as point contact. Therefore, the transmission of vibration from the internal gear 274 to the second housing 230 and the first housing 40 during operation can be reduced.

[0130] Furthermore, let's assume that internal gear 274 has already... Figure 19 The state shown in (a) is rotated clockwise (around the axis). Therefore, as Figure 21As shown, the sides of all protrusions 275 will cause the sidewall portion 231b of the recessed portion 231 to contact the contact point P6, thereby preventing further rotation of the internal gear 274. Considering that the contact point P6 is the contact between the protrusion 275 (described as circular) and the sidewall portion 231b of the recessed portion 231 (described as a straight line), this contact point is a contact within a very limited range. The circular cylinder constituting a portion of the protrusion 275 and the sidewall portion 231b of the recessed portion 231 are continuous in the axial direction (vertical direction in the figures). Therefore, the contact form between the protrusion 275 and the recessed portion 231 can be a line contact along the axial direction. It should be noted that even if the internal gear 274 will... Figure 19 In the state shown in (a), when rotating counterclockwise around the axis, the contact between the protrusion 275 and the recess 231 will still be a line contact.

[0131] Furthermore, let's assume that internal gear 274 has already been... Figure 19 The state shown in (a) moves in a direction perpendicular to the axis, for example, moving upwards as depicted in the figure. Therefore, as... Figure 22 As shown, the sides of the two protrusions 275 contact the sidewall portion 231b of the recessed portion 231 at contact point P7, thereby limiting further movement of the internal gear 274 in the direction perpendicular to the axis. Considering that contact point P7 is the contact between the protrusion 275 (described as circular) and the sidewall portion 231b of the recessed portion 231 (described as a straight line), this contact point is a contact within a very limited range. The circular cylinder constituting a portion of the protrusion 275 and the sidewall portion 231b of the recessed portion 231 are continuous in the axial direction (the vertical direction in the figures). Therefore, the contact form between the protrusion 275 and the recessed portion 231 can be a line contact along the axial direction. It should be noted that even if the internal gear 274 will... Figure 19 As shown in (a), the state moves downwards, and the contact between the protrusion 275 and the recessed portion 231 will still be a line contact.

[0132] Thus, regardless of whether the internal gear 274 has rotated clockwise around its axis or moved in a direction perpendicular to the axial direction, the contact between the protrusion 275 and the recessed portion 231 can be limited to a narrow range that can be described as line contact. This reduces the transmission of vibration from the internal gear 274 to the second housing 230. The protrusion 275 is thus formed as a first contact portion on the end face 274c on the -X direction side of the internal gear 274. Furthermore, the four recessed portions 231 are formed as second contact portions on the end face 230B on the +X direction side of the second housing 230.

[0133] Furthermore, the recessed portion 231 for restricting the movement of the internal gear 274 is formed in the second housing 230, which forms the end portion of the housing, rather than in the first housing 40, which occupies most of the size of the housing. Figure 20 This allows for a reduction in the contact area between the internal gear 274 and the housing. Furthermore, the second housing 230 serves as part of a cap covering the opening of the first housing 40, thereby reducing vibrations directed towards the first housing 40. Figure 20 The transmission of the planetary gear mechanism 20 can be suppressed. Figure 4 The noise generated.

[0134] (Implementation Plan 2)

[0135] In the first embodiment, movement of the internal gear 274 is restricted by creating line contact between a protrusion 275 formed in the internal gear 274 and a recess 231 formed in the second housing 230. In the second embodiment, the position of the protrusion is switched with the position of the recess, and the recess is formed in the internal gear while the protrusion is formed in the second housing.

[0136] like Figure 23 As shown, the outer peripheral surface 374a of the internal gear 374 according to this embodiment is constructed of a curved surface, wherein no recessed or protruding portions are formed on this surface. Figure 16 Similar to the internal gear 274 shown, six hemispherical protrusions 74c are formed on the end face 374b on the +X direction side of the internal gear 374. On the other hand, the end face 374c on the -X direction side of the internal gear 374 has four recessed portions 375 formed radially from the center (axis position) of the internal gear 374. The four recessed portions 375 overlap to form a "+", which is consistent with the reference... Figure 19 The four recessed portions 231 described are identical. Note that, as... Figure 23 As shown, the recessed portion 375 has dimensions of width w1 and depth d1. The depth d1 of the recessed portion 375 is shallower than the height h1 of the protrusion 331 formed in the second housing 330, as shown. Figure 24 As shown. Furthermore, the width w1 of the recessed portion 375 is wider than the diameter of the protrusion 331 formed in the second housing 330, as... Figure 24 As shown.

[0137] like Figure 24 As shown, the second housing 330 has an opening 330a formed at its center, and the rotor shaft 12 of the motor 10 ( Figure 4 Four protrusions 331 are arranged at equal angles around the center (axis position) of the second housing 330 on the end face 330B on the +X axial side of the second housing 330. (Example) Figure 24 As shown in (b), four protrusions 331 extend from the end face 330B by a height h1 along the +X axis. The protrusions 331 have a shape in which a hemispherical body is connected to the end face of a cylindrical column, thereby fixing a height h1 greater than the radius of the hemispherical body.

[0138] With the internal gear 374 housed within the housing, when the internal gear moves to the +X direction side, the protrusion 74c formed on the internal gear 374 in the same manner as in the first embodiment described above ( Figure 23 (b)) top and the stepped surface 46a of the first housing 40 ( Figure 20 To prevent further movement of the internal gear 374, point contact is made.

[0139] On the other hand, with the internal gear 374 housed within the housing, when the internal gear moves to the -X direction side, then as... Figure 24 As shown in (b), the protrusion 331 formed in the second housing 330 makes point contact with the bottom surface 375a of the recessed portion 375 formed in the internal gear 374 to prevent further movement of the internal gear 374.

[0140] Thus, although the internal gear 374 moves axially, the movement is limited by contact within a narrow range, which can be described as point contact. Therefore, the transmission of vibration from the internal gear 374 to the second housing 330 and the first housing 40 during operation can be reduced.

[0141] Furthermore, since this is merely a change in the position of the protrusion and the recess compared to the first embodiment, even if the internal gear 374 has rotated clockwise around the axis and moved in a direction perpendicular to the axis, the movement of the internal gear 374 is still restricted by the line contact between the side of the protrusion 331 formed in the second housing 330 and the sidewall portion 375b of the recess 375 formed in the internal gear 374. This produces the same operational effect as in the first embodiment.

[0142] (Implementation Plan 3)

[0143] In the above embodiment, as a structure for contacting the protrusions 275 and 331, groove-shaped recesses 231 and 375 overlapping in a "+" shape are formed. However, the shape of the recesses can be arbitrarily set and is not limited to a groove shape. Furthermore, the position for forming the recesses is not limited to the above form. Next, a third embodiment will be described, in which the shape and position of the recesses contacted by the protrusions differ from the above form. It should be noted that the second housing in this embodiment and... Figure 24 The second housing 330 shown is the same.

[0144] like Figure 25 and Figure 26 As shown, the outer surface 474a of the internal gear 474 according to this embodiment is constructed of a curved surface, wherein no recessed or protruding portions are formed on this surface. Figure 16 Similar to the internal gear 274 shown, six hemispherical protrusions 74c are formed on the end face 474b on the +X direction side of the internal gear 474. On the other hand, as... Figure 25 and Figure 26 As shown, four recessed portions 475 are arranged on the end face 474c on the -X direction side of the internal gear 474, and are spaced apart at equal angles around the internal gear 474 (position of the axis). Figure 24 As shown, the protrusions 331 formed in the second housing 330 are inserted into the four recesses 475.

[0145] It should be noted that, such as Figure 25 As shown, the recessed portion 475 has a depth d1 at a distance from the end face 474c. This depth d1 of the recessed portion 475 is shallower than the height h1 of the protrusion 331 formed in the second housing 330, as... Figure 24 As shown in (b). In this way, the axially moving internal gear 474 passes through the protrusion 74c and the protrusion 331 formed on the second housing 330. Figure 24 It makes point contact with the second housing 230 and the first housing 40. This reduces the transmission of vibrations from the internal gear 474 as it moves axially into the second housing 230 and the first housing 40.

[0146] like Figure 26 As shown in the enlarged view, the recessed portion 475 is divided into: a substantially straight outer edge portion 475a with a large curvature, a convex arcuate portion 475b connected to the interior of the outer edge portion 475a, and a convex arcuate portion 475c connected to the interior of the arcuate portion 475b. The recessed portion 475 has a width w2 along the circumferential direction of the internal gear 474. The width w2 is wider than... Figure 23 (a) shows the width w1 of the recessed portion 375.

[0147] Let's assume that internal gear 474 has been from Figure 26 The state shown is rotated clockwise (around the axis). Therefore, when there is rotation in the clockwise direction, each of the four recessed portions 475 contacts the protrusion 331 at contact point P8, as... Figure 27 As shown. Further rotation of the internal gear 474 is thus limited. As... Figure 27As shown in the enlarged view, contact point P8 is a point within a very limited range, through the contact between the arcuate portion 475b, described as arc-shaped, and the protrusion 331, described as circular. It should be noted that the circular cylinder constituting a part of the protrusion 331 and the arcuate portion 475b are continuous in the axial direction (vertical direction in the drawing). Therefore, the contact between the protrusion 331 and the recessed portion 475 can be a line contact along the axial direction. Even if the internal gear 474 rotates counterclockwise about its axis from the state shown in FIG. 26, the contact between the protrusion 331 and the recessed portion 475 will still be a line contact.

[0148] It should be noted that the position where the protrusion 331 contacts the recessed portion 475 is described as the arc-shaped portion 475b. However, by changing the position of the internal gear 474 in a plane perpendicular to the axial direction, the protrusion 331 can also contact the arc-shaped portion 475c. Even in this case, the arc-shaped portion 475c is formed with the same arc shape as the arc-shaped portion 475b, so that the contact with the protrusion 331 can be a line contact.

[0149] Furthermore, let's assume that internal gear 474 originates from... Figure 26 The state shown moves in a direction perpendicular to the axis, for example, moving downwards in the diagram. Therefore, as... Figure 28 As shown, the recessed portion 475, positioned at the highest point in the figure, contacts the protrusion 331 at contact point P9, thereby preventing further movement of the internal gear 474. Figure 28 As shown in the enlarged view, the contact point P9 is a very limited contact because it contacts the essentially straight outer edge portion 475a with a large curvature and the protrusion 331, which is described as circular. It should be noted that the circular cylinder forming part of the protrusion 331 and the outer edge portion 475a are continuous in the axial direction (vertical direction in the drawing). Therefore, the contact between the protrusion 331 and the recessed portion 475 can be a continuous line contact along the axial direction. It should be noted that even if the internal gear 474 will... Figure 26 As the state shown moves upward, the contact between the protrusion 331 and the recessed portion 475 will still be a line contact.

[0150] Thus, regardless of whether the internal gear 474 has rotated about its axis or moved in a direction perpendicular to the axial direction, the contact form between the protrusion 331 and the recess 475 can be limited to a narrow range that can be described as line contact. This makes it possible to suppress the movement of the planetary gear assembly 20 in the same manner as in the embodiments described above. Figure 4 The noise generated.

[0151] (Implementation Plan 4)

[0152] In the above embodiment, the contact portion on the end face of one side (second housing side) of the internal gear in the axial direction contacts the contact portion formed in the housing to restrict the movement of the internal gear. In this embodiment, the contact portion on the end portion of the internal gear on the other side in the axial direction contacts the contact portion formed in the first housing to restrict the movement of the internal gear.

[0153] like Figure 29 As shown, the outer peripheral surface 574a of the internal gear 574 is formed by a curved surface without any recesses or protrusions, which is the same as in the above embodiment. Six protrusions 575 are positioned at equal angular intervals around the center of the internal gear 574 on the end face 574B on the +X direction side of the internal gear 574. Figure 32 As shown in the enlarged view, six protrusions 575 protrude from the end face 574B at a height of h2. The protrusions 575 have a shape in which a hemispherical body is connected to the end face of a cylindrical column, thereby fixing a height h2 greater than the radius of the hemispherical body.

[0154] According to this embodiment, the second shell and Figure 4 The second housing 30 shown in the above reference example is the same.

[0155] like Figure 30 and Figure 31 As shown, the first housing 540 assembled with the second housing does not have the stop 45 formed on the first housing 40 as in the reference example. Figure 6 In this way, the internal gear 574 is received within the first housing 540 with a gap provided from the inner peripheral surface of the first housing 540. Recesses 541 are formed in a stepped surface 546a, which is formed inside the first housing 540. The recesses 541 are arranged at equal angular intervals around an axis and are inserted... Figure 29 The protrusion 575 formed in the internal gear 574 is shown. For example... Figure 32 As shown in the enlarged view, the recessed portion 541 has a depth of d2. The depth d2 of the recessed portion 541 is shallower than the height h2 of the protrusion 575 formed in the internal gear 574. Figure 32 As shown in the enlarged view, when the tip of the protrusion 575 can contact the bottom surface of the recess 541, this creates a state where the end face 574b of the internal gear 574 is away from the stepped surface 546a of the first housing 540. In this way, the internal gear, which has moved in the +X axis, will make point contact with the first housing 540 at the tip of the protrusion 575.

[0156] like Figure 31As shown, the shape of the recessed portion 541 formed on the stepped surface 546a is the same as that formed on the stepped surface 546a. Figure 26 The recessed portions 475 in the internal gear 474 shown have the same shape. Therefore, regardless of Figure 29 Whether the internal gear 574 shown has rotated about its axis or moved in a direction perpendicular to the axial direction, the contact form between the protrusion 575 and the recess 541 can be limited to a narrow range that can be described as line contact. This makes it possible to suppress the movement of the planetary gear assembly 20 in the same manner as in the embodiments described above. Figure 4 The noise generated.

[0157] (Implementation Plan 5)

[0158] The fifth embodiment of the invention will now be described with reference to the accompanying drawings. Compared with the first embodiment, as... Figure 33 As shown, the difference is that the openings are formed on both sides of the recessed portion 631 formed in the second housing 630, while the other structures are the same.

[0159] like Figure 33 As shown, an opening 630c is formed between adjacent recesses 631, extending through the second housing 630. The opening 630c is fan-shaped because it is a quarter-circular annular opening (i.e., a quarter-circular opening in which the portion of the quarter-circle extending radially outward from the center is filled). By forming openings 630c on both sides of the recesses 631 in this way, the rigidity of the sidewall portion 631b of the recesses 631 contacted by the protrusion 275 is reduced, which increases the elasticity of the sidewall portion 631b. In this way, impact and noise can be absorbed when the protrusion 275 contacts the sidewall portion 631b of the recesses 631, thereby reducing the impact of the planetary gear mechanism 20 ( Figure 4 The vibrations and noise generated are the same as those in the above-described implementation scheme. Other actions and effects are the same as in the above-described implementation scheme.

[0160] (Implementation Plan 6)

[0161] The sixth embodiment of the invention will now be described with reference to the accompanying drawings. Figure 34 As shown, the outer peripheral surface 774a of the internal gear 774 according to this embodiment is constructed of a curved surface, wherein no recessed or protruding portions are formed on this surface. Figure 16Similar to the internal gear 274 shown, six hemispherical protrusions 74c are formed on the end face 774b of the internal gear 774 on the +X direction side. On the other hand, a peripheral portion 776, erected along its outer edge in a peripheral shape, and a pair of stoppers 775 protruding inward from the peripheral portion 776 are formed on the end face 774c of the internal gear 374 on the -X direction side. The stoppers 775 are positioned at six locations spaced equally around the axis. The shape of each stopper 775 is similar to the reference... Figure 10 The stop members 45 in the reference example are identical in shape and have a herringbone shape.

[0162] like Figure 35 As shown, the second housing 730 has an opening 730a formed at its center, and the rotor shaft 12 of the motor 10 ( Figure 4 The ring body 736, centered on the position of the axis, is configured to protrude along the +X direction on the end face 730B on the +X direction side of the second housing 730, and the movement limiting protrusion 735 is formed to protrude from the ring body 736 to the outside. The movement limiting protrusion 735 is provided in six positions spaced at equal angles around the axis. Figure 36 and Figure 37 As shown, the movement limiting protrusions 735 are configured to correspond to the pair of stops 775, and the tip of each movement limiting protrusion 735 is inserted between the pair of stops 775. The shape of the movement limiting protrusions 735 is consistent with that of the reference numerals. Figure 11 The movement restriction protrusion 75 in the illustrated reference example has the same shape, thus forming a triangle.

[0163] Thus, in this embodiment, the relationship between the stop 775 and the movement limiting protrusion 735 is... Figure 9 The relationship between the stop 45 and the movement-limiting protrusion 75 shown and illustrated in the above reference example is the same. Therefore, it is consistent with the reference... Figure 12 As described above, even if the internal gear 774 rotates around its axis, the stop 775 and the movement-limiting protrusion 735 will still make line contact to limit the rotation of the internal gear 774. Additionally, as per the reference... Figure 13 As described above, even if the internal gear 774 moves in a direction perpendicular to the axis, the stop 775 and the movement-limiting protrusion 735 will still make line contact to limit the movement of the internal gear 774. This makes it possible to suppress movement from the planetary gear assembly 20 in the same manner as in the above-described embodiment. Figure 4 The noise generated.

[0164] (Modified Implementation Example)

[0165] The present invention is not limited to the above-described embodiments, but can be modified and applied in various ways. Although, for example, in the first embodiment, the protrusion 275 formed on the internal gear 274 and the recess 231 formed in the second housing 230 are each formed in four positions, the number of positions can be arbitrarily set. For example, it can be set to three positions, or it can be set to more than four positions.

[0166] Furthermore, although, for example in the first embodiment, the protrusion 275 of the contact recess 231 is formed on the end face 274c on one side (-X direction side) of the internal gear 274, a protrusion for contacting the recess can also be formed on the end face 274b on the other side (+X direction side). In this case, the recessed portion contacting these protrusions can be formed on the stepped surface 46a of the first housing 40, such as... Figure 20 As shown. Thus, the orientation of the internal gear can be stabilized by forming protrusions on both end faces of the internal gear for contacting the recessed portion. Conversely, the protrusions for forming the recessed portion can be formed only on one end face 274b on the other side (+X direction side) of the internal gear 274.

[0167] Furthermore, although in the second embodiment, the recessed portion 375 of the contact protrusion 331 is formed on the end face 374c on one side (-X direction side) of the internal gear 374, alternatively, the recessed portion may be formed only on the end face 374b on the other side (+X direction side), or the recessed portion may be formed on both end faces 374b and 374c on one and the other side. When the recessed portion is formed on the end face 374B on the other side, a new protrusion may be formed on the stepped surface 46a of the first housing 40, such as... Figure 20 As shown.

[0168] Furthermore, in the first embodiment, for example, it should be noted that the protrusion 275 contacting the recessed portion 231 has a shape in which a hemispherical body is connected to the end face of a cylindrical column; however, the shape of the protrusion 275 is arbitrary. For example, it can be a shape in which a cone is connected to the end face of a cylindrical column, and can be constructed solely of a hemispherical body within the range of the required height in which the protrusion can be fixed. If the protrusion is formed solely of a hemispherical body, there will be no cylindrical portion for line contact, thereby allowing the contact with the recessed portion 231 to be a point contact. This can further reduce the contact area between the recessed portion 231 and the protrusion 275.

[0169] Furthermore, the shapes of the recessed portions 475 and 541 in the third and fourth embodiments are not limited to the shapes described above, but can be arbitrarily set. For example, they can be rectangular or pentagonal. Even with such shapes, the contact with the protrusion having a cylindrical column can be a line contact.

[0170] Furthermore, in the fifth embodiment, the opening 630c formed in the second housing 630 is not limited to... Figure 33 The shape and size shown. For example, the opening can be divided into multiple openings, and multiple fine holes can be formed near the recessed portion 631 to add elasticity to the recessed portion 631. Furthermore, these openings can... Figure 24 The adjacent protrusions 331 shown are formed between each other, and can be formed between each other. Figure 27 The adjacent recessed portions 475 shown are formed between each other.

[0171] Furthermore, although in the sixth embodiment, the movement limiting protrusion 735 is formed on the second housing 730 and the stop pair 775 is formed on the internal gear 774, alternatively, the movement limiting protrusion 735 and the stop pair 775 can be switched, wherein the stop pair 775 is formed on the second housing 730 and the movement limiting protrusion 735 is formed on the internal gear 774. Furthermore, although the stop pair 775 is formed on the end face of the internal gear 774 on the -X direction side, alternatively, the stop pair can be formed on the end face on the +X direction side, and the movement limiting protrusion 735 can be formed on the +X direction side. In this case, the movement limiting protrusion or the stop pair can be formed on the stepped surface 46a of the first housing 40, such as... Figure 20 As shown.

[0172] Furthermore, as a modification example of the pair of movement limiting protrusions 735 and stops 775 in the sixth embodiment, the pair of movement limiting protrusions 75 and stops 45 in the above-given reference examples may be appropriately applied.

[0173] Although the above implementation provides a movement restriction protrusion 75 ( Figure 7 ) and 45 pairs of stop parts ( Figure 6 For example, an unformed example (illustrated in the reference example, Figure 16 (As shown), but the invention is not limited thereto, and the movement-limiting protrusion and stop pair of the reference example may exist. That is, in addition to forming a first contact portion and a second contact portion in the axial direction (as in the above embodiment), the first protrusion portion and the second protrusion portion may be formed in a direction perpendicular to the axial direction.

[0174] Furthermore, in the above-described reference example, a pair of stops 45 are disposed in the first housing 40, and a movement-limiting protrusion 75 inserted between the pair of stops 45 is disposed on the internal gear 74. However, the present invention is not limited thereto, but the positions in which the pair of stops 45 and the movement-limiting protrusion 75 are disposed can be switched, such that the movement-limiting protrusion 75 is disposed on the inner peripheral surface of the first housing 40, and the pair of stops 45 is disposed on the outer peripheral surface of the internal gear 74.

[0175] 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.

[0176] 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.

[0177] Furthermore, although the movement of the convex surfaces of the stop 45 is limited to the plane of the protrusion 75 to result in line contact therebetween, line contact can also be achieved by causing contact of other shapes. (See below for further details.) Figure 38 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 first housing 40 is different from... Figure 9 The structure shown in the magnified view is the same. Figure 38 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 first housing 40 after the actuator's operation. Figure 38 As shown, the contact between the pair of stops 45 and the movement-limiting protrusion 175 is a contact between convex surfaces, therefore, the contact points P10 and P11 between the pair of stops 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.

[0178] Furthermore, there are no limitations on this, where line contact can be achieved through a first 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.

[0179] It should be noted that in another example of achieving the above-mentioned line contact, the configuration of the internal gear at the position of making line contact can be interchanged with the configuration of the first housing.

[0180] 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.

[0181] 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.

[0182] Furthermore, although the above embodiment is described in relation to the case where the reduction gear is used to reduce the rotation of 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".

[0183] 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.

[0184] 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.

[0185] 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.

[0186] 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.

[0187] 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.

[0188] Furthermore, instead of the structure in the above embodiments that restricts movement within the housing by creating an axial line contact between the movement-restricting protrusion (first protrusion) and the stop pair (second protrusion), the structure can be a structure in which movement within the housing is restricted by point contact between the movement-restricting protrusion (first protrusion) and the stop pair (second protrusion). More specifically, Figure 5 The stop pair (second protrusion) 45 may have a shape that is discontinuous in the axial direction, and Figure 7 The movement restriction protrusion (first protrusion) 75 may have a shape that is discontinuous in the axial direction.

[0189] Explanation of reference symbols

[0190] 1: Actuator

[0191] 10: Motor

[0192] 11: Motor main unit

[0193] 12: Rotation axis

[0194] 20: Planetary gear mechanism

[0195] 30: Second shell

[0196] 30a: Open

[0197] 40: First shell

[0198] 41: First position

[0199] 42: Second position

[0200] 43: Third position

[0201] 43a: Opening

[0202] 44: Cylinder

[0203] 44a: Inner wall

[0204] 45: Stop (second protruding part)

[0205] 45a: Upright part

[0206] 45b: Connection part

[0207] 45c: Top

[0208] 46: Cylinder

[0209] 47: Internal teeth section

[0210] 50: Casing

[0211] 60: Planetary gear mechanism

[0212] 70: First planetary gear mechanism

[0213] 71: Sun Gear

[0214] 71a: Sun tooth portion

[0215] 72: Planetary Gears

[0216] 72a: Planetary tooth section

[0217] 73: Stent

[0218] 73a: Accommodation opening

[0219] 74: Internal gear

[0220] 74a: Internal teeth section

[0221] 74b: Outer peripheral surface

[0222] 75: Movement restriction protrusion (first protrusion)

[0223] 75a: Sloping edge portion

[0224] 75b: Top

[0225] 75c: Notch portion

[0226] 76: Sales

[0227] 80: Second planetary gear mechanism

[0228] 81: Sun Gear

[0229] 81a: Sun tooth portion

[0230] 82: Planetary Gear

[0231] 82a: Planetary tooth section

[0232] 83: Bracket

[0233] 84: Gear retaining part

[0234] 84a: Accommodation opening

[0235] 85: Output shaft holding section

[0236] 85a: Assembly hole

[0237] 86: Output shaft

[0238] 86a: Output gear

[0239] 87: Sales

[0240] 90: Contact Area

[0241] 140: First shell

[0242] 141: Concave component

[0243] 174: Internal gear

[0244] 175: Movement restriction protrusion (first protrusion)

[0245] 230: Second shell

[0246] 230a: Open

[0247] 230b: End face

[0248] 231: Depressed portion

[0249] 231a: Bottom surface

[0250] 231b: Sidewall portion

[0251] 274: Internal gear

[0252] 274a: Outer peripheral surface

[0253] 274b: End face

[0254] 274c: End face

[0255] 275: Protrusion

[0256] 330: Second shell

[0257] 330a: Open

[0258] 330b: End face

[0259] 331: Protrusion

[0260] 374: Internal gear

[0261] 374a: Outer peripheral surface

[0262] 374B: End face

[0263] 374c: End face

[0264] 375: Depressed portion

[0265] 375a: Bottom surface

[0266] 375B: Sidewall section

[0267] 474: Internal gear

[0268] 474a: Outer surface

[0269] 474b: End face

[0270] 474c: End face

[0271] 475: Depressed portion

[0272] 475a: Outer edge portion

[0273] 475b: Curved section

[0274] 475c: Curved section

[0275] 540: First Shell

[0276] 541: Depressed portion

[0277] 546a: Stepped surface

[0278] 574: Internal gear

[0279] 574a: Outer peripheral surface

[0280] 574b: End face

[0281] 575: Protrusion

[0282] 630: Second shell

[0283] 630c: Open

[0284] 631: Depressed portion

[0285] 631B: Sidewall section

[0286] 730: Second Shell

[0287] 730a: Open

[0288] 730B: End face

[0289] 735: Movement restriction protrusion

[0290] 736: Ring Body

[0291] 774: Internal gear

[0292] 774a: Outer peripheral surface

[0293] 774b: End face

[0294] 774c: End face

[0295] 775: Stop

[0296] 776: Surrounding Area

Claims

1. A device for suppressing noise generated in a planetary gear mechanism, characterized in that, include: An internal gear having a first contact portion formed on an end face of the internal gear on an axially upward side; as well as The housing includes a first housing and a second housing, the first housing for accommodating the internal gear, and the second housing having a second contact portion for restricting movement of the internal gear by contacting the first contact portion formed on the internal gear. The housing is configured to accommodate the internal gear, such that the internal gear is a floating internal gear capable of moving relative to the housing, wherein a gap exists between the inner circumferential surface of the housing and the outer circumferential surface of the internal gear. Wherein, one of the first contact portion and the second contact portion includes a plurality of protrusions formed along the axial direction, and the other of the first contact portion and the second contact portion includes a plurality of recesses into which the plurality of protrusions are inserted, each recess being formed such that the longest dimension of the recess is aligned with the radial direction of the housing. Two of the plurality of recessed portions are spaced apart circumferentially around the second housing.

2. The device according to claim 1, characterized in that, The protrusion is a post, and The movement of the internal gear in the direction perpendicular to the axial direction is restricted by the line contact between the side of the column and the side wall of the recessed portion.

3. The device according to claim 1, characterized in that, The tip of the protrusion is hemispherical, and The movement of the internal gear in the axial direction is restricted by the contact between the pointed portion and the bottom surface of the recessed portion.

4. The device according to claim 1, characterized in that, The device further includes a plurality of paired first protrusions spaced apart from each other on the outer peripheral surface of the internal gear, and the first protrusions are spaced apart in a circumferential direction. A plurality of second protrusions are formed on the inner circumferential surface of the housing, the plurality of second protrusions being configured to be inserted between pairs of first protrusions that are spaced apart around the circumferential direction.

5. The device according to claim 4, characterized in that, At least one of the first protrusions makes line contact with the second protrusion.

6. The device according to any one of claims 1 and 4 to 5, characterized in that, The first housing of the housing has an open portion on one side in the axial direction. The second housing is attached to the first housing to block the open portion.

7. A planetary gear mechanism, characterized in that, include: Device for suppressing noise generated in a planetary gear assembly according to any one of claims 1 to 5; One or more planetary gears meshing with the internal gear; A sun gear that meshes with one or more planetary gears and is positioned at the center of one or more planetary gears; as well as A bracket that can rotatably support the one or more planetary gears.

8. An actuator, characterized in that, include: The planetary gear device according to claim 7; as well as A motor connected to the planetary gear assembly for driving the planetary gear assembly.

Images