Gear housing for planetary gear units with structurally separated internal gears

Abstract

The present application provides an apparatus for suppressing noise generated in a planetary gear device, including: an inner gear having an inner peripheral surface on which an inner tooth portion is formed; the inner gear having an outer peripheral surface having a protrusion portion formed on at least a portion thereof in a direction from one side to the other side in an axial direction of the inner gear, the inner gear having an open end surface extending between the inner peripheral surface and the outer peripheral surface on an end portion located on the other side of the inner gear; a substantially cylindrical housing for accommodating the inner gear, movement of the inner gear in a circumferential direction within the housing being restricted by contact with the protrusion portion of the inner gear, the housing having a contact surface portion provided to face the open end surface on the other side of the inner gear, and the open end surface on the other side of the inner gear having a contact portion projecting toward the contact surface portion side, movement of the inner gear toward the contact surface portion side being restricted by contact in the axial direction with the contact surface portion.

Description

Technical Field

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

[0002] Planetary gears are used in various technologies, such as automobiles and robots. Since planetary gears are constructed by combining multiple gears, they generate noise and vibration during operation. Technologies have been proposed to suppress the generation of noise and vibration when planetary gears operate.

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

[0004] [Prior Art References]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Unexamined Patent Application Publication No. H6-74835 Summary of the Invention

[0007] [Problems to be solved by the present invention]

[0008] In the planetary gear device of Patent Document 1, the outer peripheral surface of the internal gear and the inner peripheral surface of the housing are formed to fit together. Therefore, when the internal gear moves during operation, contact occurs between the outer peripheral surface of the internal gear and the inner peripheral surface of the housing, with a relatively wide range of contact. Consequently, in a state where contact exists between the internal gear and the housing, vibrations of the planetary gear mechanism that propagate to the internal gear are easily transmitted to the housing, leading to a problem: the planetary gear device also tends to generate noise.

[0009] The present invention is intended to solve problem areas such as those described above, and has as its object to provide a separate structural unit for an internal gear and a housing, capable of suppressing the transmission of vibrations from a planetary gear mechanism and noise generated by the planetary gear device, and to provide a planetary gear device equipped with the separate structural unit and an actuator equipped with the planetary gear device.

[0010] [Solution to the problem]

[0011] According to the present invention, an apparatus for suppressing noise generated in a planetary gear device includes: an internal gear having an inner peripheral surface with an internal tooth portion formed thereon; wherein the internal gear has an outer peripheral surface with a raised portion formed on at least a portion thereof in a direction from one side to the other side in an axial direction of the internal gear, and wherein the internal gear has an open end surface extending between the inner peripheral surface and the outer peripheral surface on an end portion located on the other side of the internal gear; and a substantially cylindrical housing for accommodating the internal gear, wherein movement of the internal gear in a circumferential direction within the housing is restricted by contact with the raised portion of the internal gear, wherein the housing has a contact surface portion provided so as to face the open end surface on the other side of the internal gear, and wherein the open end surface on the other side of the internal gear has a contact portion protruding toward a contact surface portion side, wherein the contact portion restricts movement of the internal gear toward the contact surface portion side by contact with the contact surface portion in the axial direction.

[0012] In some embodiments, the contact portion includes at least three contact protrusion portions that make point contact with the contact surface portion.

[0013] In some embodiments, the contact portion includes a plurality of contact portions protruding from the contact surface portion side, and wherein the plurality of contact portions are provided on the opening end surface at equal intervals in the circumferential direction.

[0014] In some embodiments, the contact portion includes a plurality of contact portions protruding from the contact surface portion side, and wherein the plurality of contact portions are spaced apart on the opening end surface at unequal intervals in the circumferential direction.

[0015] In some embodiments, the contact portion is configured such that the further a cross section thereof perpendicular to the axial direction is from the opening end surface on the other side, the smaller the area of ​​the cross section becomes.

[0016] In some embodiments, the contact portion is a pyramid or cone-shaped body, wherein the tip portion of the contact surface portion side is a top.

[0017] In some embodiments, in the contact portion, the tip portion of the contact surface portion has a spherical surface shape.

[0018] In some embodiments, the contact portion has a rod-shaped extension portion extending from the open end surface toward the contact surface portion, and a hemispherical surface portion provided on the tip of the extension portion.

[0019] In some embodiments, the contact portion has a plus-sign cross-sectional shape in the cross section perpendicular to the axial direction.

[0020] In some embodiments, the second contact portion is provided on the open end surface on the one side to protrude from the one side.

[0021] In some embodiments, the internal gear and the housing are made of synthetic resin, and wherein the internal gear is formed of a synthetic resin having a lower hardness than the synthetic resin used to form the housing.

[0022] According to the present invention, a planetary gear device includes: an apparatus for suppressing noise generated in the planetary gear device; at least one planetary gear meshing with the internal gear; a sun gear meshing with the at least one planetary gear and positioned at the radial center along the housing; and a bracket capable of rotatably supporting the one or more planetary gears.

[0023] In some embodiments, the planetary gear device also includes: a second sun gear, which rotates with the rotation of the bracket; one or more second planetary gears, which are arranged on the periphery of the second sun gear and meshed with the second sun gear; a second bracket, which is capable of rotatably supporting the one or more second planetary gears; and a second housing, in which internal teeth meshing with the one or more second planetary gears are formed on the inner peripheral surface of the second housing, wherein the housing and the second housing are formed integrally.

[0024] According to the present invention, a planetary gear device includes at least two stages of planetary gear mechanisms, each stage of the planetary gear mechanism includes: a sun gear; one or more planetary gears, which are arranged on the periphery of the sun gear for engaging with the sun gear; and a bracket, which is capable of rotatably supporting the one or more planetary gears, wherein in the at least two stages of planetary gear mechanisms, the planetary gear mechanism operating at the highest speed includes a device for suppressing noise generated in the planetary gear device, wherein the one or more planetary gears of the planetary gear mechanism are engaged with the internal gear, and wherein in the at least two stages of planetary gear mechanisms, the planetary gear mechanism operating at the lowest speed includes a housing, which includes internal teeth formed on the inner peripheral surface of the housing and engaged with the one or more planetary gears of the planetary gear mechanism.

[0025] A planetary gear device and an actuator according to the present invention include: a planetary gear device; and a motor connected to the planetary gear device and used to drive the planetary gear device.

[0026] A structural unit for separating an internal gear and a housing includes: an internal gear having a first raised portion formed on the outer peripheral surface, the first raised portion extending from one side to the other side in the axial direction; and a housing, wherein a second raised portion extending from one side to the other side in the axial direction is formed on the inner peripheral surface, and the housing accommodates the internal gear in a state where there is a gap with the inner peripheral surface, wherein: movement of the internal gear within the interior of the housing is restricted by line contact between the first raised portion and the second raised portion.

[0027] Among the first raised portion and the second raised portion, one raised portion may be formed as a pair with a spacing therebetween, and the other raised portion may be arranged to be easily inserted between the one raised portion formed as a pair; and among the contact positions of the one raised portion and the contact positions of the other raised portion that are in line contact with each other, at least one contact position may be a curved surface.

[0028] The one raised portion may be the second raised portion, and the other raised portion may be the first raised portion; and when cut by a plane perpendicular to the axial direction, the first raised portion may have a triangular cross-section, and the first raised portion may be in line contact with the second raised portion at an inclined surface formed in the plane.

[0029] Of the contact position of the first convex portion and the contact position of the second convex portion that are in line contact with each other, one contact position may be a convex curved surface, and the other contact position may be a flat surface.

[0030] The contact position of the first convex portion and the contact position of the second convex portion that are in line contact with each other may be convex curved surfaces.

[0031] Of the contact position of the first convex portion and the contact position of the second convex portion that are in line contact with each other, one contact position may be a convex curved surface, and the other contact position may be a concave curved surface.

[0032] The internal gear and the housing may be made of synthetic resin; and the internal gear may be formed of a synthetic resin having a lower hardness than the synthetic resin used to form the housing.

[0033] According to the present invention, a structural unit for separating an internal gear and a housing includes: an internal gear having: an inner peripheral surface on which an internal tooth portion is formed; an outer peripheral surface on which a raised portion is formed, at least a portion of the raised portion being in a direction from one side to the other side in the axial direction; and an open end surface, the open end surface extending between the inner peripheral surface and the outer peripheral surface on the end portion located on the aforementioned other side; and a cylindrical housing, the cylindrical housing being used to accommodate the internal gear, wherein the movement of the internal gear in the circumferential direction within the housing is restricted by contact with the raised portion of the internal gear, wherein: the housing has a contact surface portion, the contact surface portion is arranged to face the open end surface on the other side of the internal gear; and the open end surface on the other side has a contact portion protruding toward the contact surface portion side, wherein the contact portion restricts the movement of the internal gear toward the contact surface portion side by contact with the contact surface portion in the axial direction.

[0034] The planetary gear device according to the present invention includes: a separate structural unit for 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 bracket capable of rotatably supporting the one or more planetary gears.

[0035] The structure may also include a second sun gear, which rotates similarly to the rotation of the bracket as the bracket rotates; one or more second planetary gears, which are arranged on the periphery of the second sun gear and mesh with the second sun gear; a second bracket, which is capable of rotatably supporting the one or more second planetary gears; and a second shell, in which internal teeth meshing with the one or more second planetary gears are formed on the inner peripheral surface of the second shell, wherein: the shell and the second shell can be formed integrally.

[0036] According to the present invention, the planetary gear device includes: at least two-stage planetary gear mechanisms, each stage of the planetary gear mechanism includes: a sun gear; one or more planetary gears, the one or more planetary gears being arranged on the periphery of the sun gear for engaging with the sun gear; and a bracket, the bracket being capable of rotatably supporting the one or more planetary gears, wherein: in the at least two-stage planetary gear mechanism, the planetary gear mechanism operating at the highest speed includes a separate structural unit for the internal gear and the housing as described above, wherein the one or more planetary gears of the planetary gear mechanism are engaged with the internal gear; and in the at least two-stage planetary gear mechanism, the planetary gear mechanism operating at the lowest speed includes a housing, wherein internal teeth engaging with the one or more planetary gears of the planetary gear mechanism are formed on the inner peripheral surface.

[0037] An actuator according to the present invention includes: a planetary gear device as described above; and a motor connected to the planetary gear device for driving the planetary gear device.

[0038] [Effects of the Invention]

[0039] In the present invention, the contact range between the internal gear and the housing is narrower than in conventional systems, 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 reduces the noise generated by the planetary gear device that accompanies the vibrations of the planetary gear mechanism.

[0040] [question]

[0041] To provide a separate structural unit for the internal gear and the housing, the structural unit enables suppression of transmission of vibrations from the planetary gear mechanism and suppression of noise generated by the planetary gear device.

[0042] [Solution]

[0043] 20. The camshaft of claim 19, wherein the guide rail is constructed so that the guide rails are constructed so that the gears are in a continuous line, and wherein the guide rails have a camming element and a cylindrical outer shell that is adapted to move relative to the guide rail. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a perspective view of an actuator according to an embodiment of the present invention.

[0045] Figure 2 For Figure 1 Front view of the actuator as viewed by arrow AII.

[0046] Figure 3 For Figure 2 A cross-sectional view of the actuator taken along section line III-III in FIG.

[0047] Figure 4 FIG. 1 is an assembled perspective view of an actuator according to an embodiment of the present invention.

[0048] Figure 5 FIG. 4 is a cross-sectional view of a second housing according to an embodiment of the present invention.

[0049] Figure 6 is a perspective view of a second housing according to an embodiment of the present invention.

[0050] Figure 7 is a perspective view of a first planetary gear mechanism according to an embodiment of the present invention.

[0051] Figure 8 is a perspective view of a second planetary gear mechanism according to an embodiment of the present invention.

[0052] Figure 9 : is a diagram for explaining the relationship between the second housing and the internal gear according to the embodiment according to the present invention.

[0053] Figure 10 For attention formed in Figure 9 Illustrative illustration of the stop in the second housing is shown.

[0054] Figure 11 For attention formed in Figure 9 Illustrative illustration of the movement limiting projection on the internal gear shown.

[0055] Figure 12 To illustrate the Figure 9 The diagram shows a state in which the internal gear rotates about the axis and contacts the second housing.

[0056] Figure 13 To illustrate the Figure 9 The diagram shows a state in which the internal gear moves in a direction perpendicular to the axis and contacts the second housing.

[0057] Figure 14 To illustrate when Figure 12 The diagram shows the state of contact between the second housing and the internal gear when viewed with arrow XIV.

[0058] Figure 15 For the general Figure 11 A schematic diagram comparing the movement-limiting protrusion shown with another example of the movement-limiting protrusion.

[0059] Figure 16 An explanatory diagram for focusing attention on a contact position between an internal gear and a second housing according to another embodiment of the present invention.

[0060] 17 is a diagram accompanying the description of a first modified example of the internal gear according to the embodiment of the present invention, wherein Figure 17A is a rear view of an internal gear as a first modified example, and Figure 17B It is a right side view of the gear.

[0061] FIG. 18 is a schematic diagram comparing the protruding portion having a sharp tip and the protruding portion having a rounded tip shown in FIG. 17 .

[0062] 19 is a diagram accompanying the description of a second modified example of the internal gear according to the embodiment of the present invention, wherein Figure 19A is a rear view of an internal gear as a second modified example, and Figure 19B It is a right side view of the gear.

[0063] 20 is a diagram accompanying the description of a third modified example of the internal gear according to the embodiment of the present invention, wherein Figure 20A is a rear view of an internal gear as a third modified example, and Figure 20B It is a right side view of the gear.

[0064] 21 is a diagram accompanying the description of a fourth modified example of the internal gear according to the embodiment of the present invention, wherein Figure 21A is a rear view of an internal gear as a fourth modified example, and Figure 21B It is a right side view of the gear.

[0065] 22 is a diagram accompanying the description of a fifth modified example of the internal gear according to the embodiment of the present invention, wherein Figure 22A is a rear view of an internal gear as a fifth modified example, and Figure 22B It is a right side view of the gear.

[0066] 23 is a diagram accompanying the description of a sixth modified example of the internal gear according to the embodiment of the present invention, wherein Figure 23A is a rear view of an internal gear as a sixth modified example, and Figure 23B It is a right side view of the gear.

[0067] 24 is a diagram accompanying the description of a seventh modified example of the internal gear according to the embodiment of the present invention, wherein Figure 24A is a rear view of an internal gear as a seventh modified example, and Figure 24B It is a right side view of the gear.

[0068] 25 is a diagram accompanying the description of an eighth modified example of the internal gear according to the embodiment of the present invention, wherein Figure 25A is a rear view of an internal gear as an eighth modified example, and Figure 25B It is a right side view of the gear.

[0069] 26 is a diagram accompanying the description of a ninth modified example of the internal gear according to the embodiment of the present invention, wherein Figure 26A is a rear view of an internal gear as a ninth modified example, and Figure 26B It is a right side view of the gear.

[0070] 27 is a diagram accompanying the description of a 10th modified example of the internal gear according to the embodiment of the present invention, wherein Figure 27A is a rear view of an internal gear as a 10th modified example, and Figure 27B It is a right side view of the gear.

[0071] 28 is a diagram accompanying the description of an 11th modified example of the internal gear according to the embodiment of the present invention, wherein Figure 28A is a rear view of an internal gear as an 11th modified example, and Figure 28B It is a right side view of the gear.

[0072] 29 is a diagram accompanying the description of a 12th modified example of the internal gear according to the embodiment of the present invention, wherein Figure 29A is a rear view of an internal gear as a 12th modified example, and Figure 29B It is a right side view of the gear. DETAILED DESCRIPTION

[0073] The following will describe a structural unit for separating an internal gear and a housing, a planetary gear device, and an actuator according to an ideal embodiment of the present invention with reference to the accompanying drawings. Note that, to facilitate understanding of the drawings, each drawing shows an orthogonal coordinate system in which the X-axis is parallel to the axial direction of the actuator 1 according to the embodiment of the present invention, and the Y-axis and Z-axis are perpendicular to the X-axis.

[0074] (Structure of Actuator 1)

[0075] like Figure 1 and Figure 2 As shown, the actuator 1 includes, for example, a motor 10 and a planetary gear device 20 connected to the motor 10 .

[0076] The motor 10 has, for example, a motor body 11 and a rotating shaft 12. Figure 3 and Figure 4 The motor 10 rotates the rotary shaft 12 under the control of a control portion (not shown) to drive the planetary gear device 20 .

[0077] The planetary gear device 20 reduces the speed by a predetermined reduction ratio. Figure 1 The planetary gear device 20 includes, for example, a housing 50 and a planetary gear mechanism 60 housed in the housing 50, the housing having a first housing 30 and a second housing 40, as shown. Figure 3 and Figure 4 shown.

[0078] The first housing 30 is a member for attaching the motor 10 to the planetary gear device 20, for example. In addition, the first housing 30 is assembled with the second housing 40 to form an accommodation space S for accommodating the planetary gear mechanism 60, as shown in FIG. Figure 5 As shown. Figure 4 As shown, an opening 30a is formed in the center of the first housing 30, and the rotating shaft 12 of the motor 10 passes through the opening. The rotating shaft 12 passing through the opening 30a is fixed (connected) to the sun gear 71 of the planetary gear mechanism 60, as described below. The first housing 30 is formed by injection molding and is made of, for example, a synthetic resin.

[0079] The second housing 40 is open on the side ("one side") connected to the first housing 30, for example, Figure 5 and Figure 6shown, and Figure 4 The planetary gear mechanism 60 shown can be accommodated in the second housing from the open portion. 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 in the axial direction. 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, Figure 5 As shown, the second housing 40 has a first position 41 in which the first planetary gear mechanism 70 is accommodated, a second position 42 in which the second planetary gear mechanism 80 is accommodated, and a third position 43 in which the output gear 86a of the second planetary gear mechanism 80 protrudes outward.

[0080] For example, Figure 5 and Figure 6 As shown, the first position 41 of the second housing 40 has a cylinder 44 and a stopper (second protruding portion) 45 that extends in the axial direction (from one side toward the other side in the axial direction). When divided in a cross section perpendicular to the axial direction, the stopper 45 has a cross section of a herringbone shape, wherein its shape and size are constant in the axial direction. The stopper 45 is formed within a portion of the first position 41 in the axial direction, but may alternatively be formed within the entire range thereof. For example, as Figure 9 As shown, the stoppers 45 are arranged to form a pair in the circumferential direction of the inner wall 44a of the cylinder 44. For example, the pair of stoppers 45 are arranged at six positions on the inner wall 44a of the cylinder 44 at equal intervals. Figure 10 As shown, the cross-sectional shape of each stopper 45 includes a vertical portion 45a that forms an arc gradually rising from the inner wall 44a of the cylinder 44, a rounded top portion 45c, and a connecting portion 45b for connecting the vertical portion 45a and the top portion 45c during expansion. It should be noted that the cross-sectional shape and size of the stopper 45 are constant in the axial direction. Therefore, for example, Figure 6 It can be understood that the upright portion 45a, the connecting portion 45b and the top portion 45c are curved surfaces that are not curved in a direction parallel to the axis. Figure 9 A movement restricting projection 75 of the internal gear 74 shown and described below is inserted between the pair of stoppers 45 to restrict movement of the internal gear 74 within the second housing 40 .

[0081] For example, Figure 5 and Figure 6 As shown, the second portion 42 of the second housing 40 has a cylinder 46 and an inner tooth portion 47 formed on the inner wall of the cylinder 46. The inner tooth portion 47 is oblique, for example, at an angle relative to the axial direction. That is, the second portion 42 having the inner tooth portion 47 is configured as a helical gear, for example.

[0082] The third portion 43 of the second housing 40 is formed into a cylindrical body, for example, and has an opening 43a through which the output gear 86a of the planetary gear mechanism 60 passes. Figure 4 The torque output from the output gear 86a can be transmitted to an external mechanism. The second housing 40 is formed by injection molding and is made of, for example, synthetic resin.

[0083] In addition, for the sake of convenience in this manual, Figures 4 to 6 , the side of the second housing 40 that is open so as to be attached to the first housing 30 is referred to as "one side" (-X direction side), and the side of the second housing 40 having the opening 43a of the third position 43 is referred to as "the other side" (+X direction side), which is the opposite side. However, the present invention is not limited to this, and the side of the second housing 40 having the opening 43a of the third position 43 may be referred to and interpreted as one side, and the side of the second housing 40 that is open for attachment to the first housing 30 may be referred to and interpreted as the other side.

[0084] For example, Figure 4 As shown, the planetary gear mechanism 60 is housed in 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 includes, for example, a first planetary gear mechanism 70 and a second planetary gear mechanism 80 arranged in the axial direction.

[0085] For example, Figure 7 As shown, the first planetary gear mechanism 70 includes: a sun gear 71; three (or more) planetary gears 72 arranged around the periphery of the sun gear 71; a bracket 73 for rotatably supporting the three (or more) planetary gears 72; and an internal gear 74. Figure 7 Only two planetary gears 72 are shown in the perspective view of FIG, but another planetary gear 72 is arranged at a position on the back side and is blocked by the bracket 73.

[0086] 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 tooth portion 71a has, for example, helical teeth cut at an angle relative to the axis of the sun gear 71. That is, the sun gear 71 is, for example, a helical gear.

[0087] The planetary gears 72 are, for example, external gears with planetary teeth 72a formed on their outer peripheral surfaces. These teeth 72a have, for example, helical teeth cut at an angle relative to the axis of the planetary gears 72. That is, the planetary gears 72 are, for example, helical gears. The three planetary gears 72 are arranged at equal intervals on a circle centered on the axis of the first planetary gear mechanism 70. The sun gear 71 is positioned between the three planetary gears 72, with its teeth 71a meshing with the corresponding teeth 72a of the three planetary gears 72.

[0088] The bracket 73 is formed into, for example, a cylindrical shape, in which three receiving openings 73a for receiving the planetary gears 72 are formed in the outer peripheral surface of the bracket. Each of the planetary gears 72 is rotatably supported in the corresponding receiving opening 73a by a pin 76 facing the axial direction, as shown in FIG. Figure 3 The planetary gear 72 is attached in a state where, for example, a portion of the planetary tooth portion 72a protrudes from the outer peripheral surface of the holder 73. Thereby, the planetary tooth portion 72a can mesh with the inner tooth portion 74a of the internal gear 74, as described below.

[0089] An inner 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. Internal gear portion 74a is, for example, a helical gear having helical teeth cut at an angle relative to the axis of internal gear 74. The rounded diameter of the tooth tips of internal gear 74 is larger than the diameter of cylindrical holder 73. Therefore, holder 73, which holds planetary gears 72, is accommodated within internal gear 74. Planetary gear portions 72a protruding from the outer peripheral surface of holder 73 mesh with internal gear portion 74a of internal gear 74.

[0090] Furthermore, a movement restricting projection 75 (first projection) that enters a gap between a pair of stoppers 45 formed on, for example, the inner wall 44a of the second housing 40 is formed on the outer peripheral surface of the internal gear 74, as shown in FIG. Figure 9 As shown. There are provided movement limiting protrusions 75 corresponding to the pairs of stoppers 45 formed in six positions, for example, similar to the pairs of stoppers 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 portion 75b positioned at a position where the inclined edge portions 75a rising from both sides intersect. Figure 7As shown, the cross-sectional shape and size of the movement limiting projection 75 are constant in the axial direction (having a constant extension from one side to the other side in the axial direction), and therefore the inclined edge portion 75a of the movement limiting projection 75 configures a flat area. It is to be noted that although the movement limiting projections 75 are formed over the entire width of the internal gear 74, they may alternatively be formed in only a portion of the internal gear range. The internal gear 74 is made of, for example, a synthetic resin. It is to be noted that, as described below, the internal gear 74 is formed of a hardness ratio of Figure 9 The synthetic resin of the second housing 40 shown is formed of a synthetic resin having low hardness.

[0091] The internal gear 74 has a contact projection (contact portion) 742 projecting axially from an end surface 740 on the other axial side. The other end surface 740 is an open end surface extending between the inner and outer peripheral surfaces on the other side and the axial portion. The contact projection 742 axially contacts the second housing 40. Within the second housing 40, the surface contacted by the contact projection 742 is the contact surface 411, which restricts the movement of the internal gear 74 toward the other axial side by contacting the end portion on the other axial side within the second housing 40. The contact surface 411 is positioned facing the other end surface 740 of the internal gear. Note that while the contact surface 411 is positioned on the other side of the first position 41, it also serves as the end surface on the second position 42 in the present invention. When housed within the second housing 40, the internal gear 74 axially contacts the contact surface 411 of the second housing 40 via the contact projection 742.

[0092] The contact protrusions 742 protrude toward the contact surface portion 411. In this embodiment, these contact protrusions 742 are arranged in a plurality on the end face 740 along the circumferential direction. The number of contact protrusions 742 provided can be any number as long as the configuration is such that the gear 74 is in stable contact with the contact surface portion 411 within the second housing 40, for example, a configuration in which contact with the contact surface portion 411 occurs without axial tilt and is centered in the axial direction. At least three contact protrusions 742 that make point contact with the contact surface portion 411 are provided on the end face 740. In addition, the contact protrusions 742 may protrude in a plurality at equal intervals along the circumferential direction on the end face (open end face) 740 (with spaces between them), or may protrude in a plurality at unequal intervals along the circumferential direction on the end face 740 (with spaces between them). In addition, there is no specific limitation on the number of contact protrusions 742, and at least one should be provided. Furthermore, the contact projection 742 may be configured so that the area of ​​the cross section perpendicular to the axial direction decreases the further away from the end surface 740, which is the open end surface on the other side. Furthermore, the contact projection 742 may be provided in the gear 74 in the same manner as the end surface 740, on the open end surface on the side to which the first housing 30 is attached. Doing so can suppress the transmission of vibrations to and from the first housing 30.

[0093] The contact projection 742 contacts the second housing 40 on the other side (in the axial direction) of the internal gear 74 to become a vibration path to the second housing 40 for vibration generated by the side of the internal gear 74. The contact projection 742 has a smaller area for the cross section perpendicular to the axial direction of the portion of the internal gear 74 that contacts the second housing 40 in the axial direction than the cross-sectional area when the end face 740 would contact the second housing 40 in the axial direction.

[0094] The contact protrusion 742 may be configured such that the area of ​​the cross section perpendicular to the axial direction gradually decreases toward the other side in the axial direction (i.e., toward the contact surface portion 411). The contact protrusion 742 reduces the transmission of vibration generated in the internal gear 74 (i.e., vibration driven by the first planetary gear mechanism 70) to the second housing 40.

[0095] In this embodiment, the contact protrusion 742 is formed into a hemispherical shape. Figure 3 and Figure 7 As shown, the contact surface portion 411 of the second housing 40 on the other side in the axial direction is contacted (by point contact). This more effectively suppresses the transmission of vibration from the internal gear 74 side to the second housing 40 in the axial direction.

[0096] While the contact projection 742 of this embodiment has a hemispherical structure, it can be configured in any shape as long as it reduces the area of ​​vibration propagation in the axial direction to the other end. For example, the contact projection 742 can be formed in a conical body, with the tip portion on the contact surface portion 411 side being the top. An internal gear equipped with the contact projection described above is described as Modifications 1 to 11 of the internal gear used in the separate structural unit, planetary gear device, and actuator according to the present invention.

[0097] like Figure 9 As shown, the second housing 40 and the internal gear 74 are physically separated, and a gap is formed between the second gear and the internal gear when the actuator 1 is not in operation. Consequently, the internal gear 74 floats within the second housing 40, allowing rotation about the axial direction and movement within the second housing 40 in a direction perpendicular to the axial direction by an amount equivalent to the gap provided between the internal gear 74 and the second housing 40. Furthermore, the stopper 45 formed on the internal gear 74 contacts the movement-limiting projection 75, preventing further movement of the internal gear 74.

[0098] The second planetary gear mechanism 80 (which is another planetary gear mechanism) includes, for example, a sun gear 81, three planetary gears 82, a carrier 83 that rotatably supports the three planetary gears 82, and an output shaft 86. Figure 8 Please note that although for convenience, Figure 8 Only two planetary gears 82 are shown in the perspective view of FIG, but another planetary gear 82 is arranged at a position on the back side and is blocked by the bracket 83.

[0099] The sun gear 81 is an external gear on which a sun tooth portion 81a is formed on, for example, an outer peripheral surface, and is fixed (connected) to the carrier 73 of the first planetary gear mechanism 70 in a state where the axes are aligned together, as shown in FIG. Figure 7 As shown. Thus, as the carrier 73 of the first planetary gear mechanism 70 rotates, the sun gear 81 rotates in the same manner as (linked for synchronization with) the rotation of the carrier 73 of the first planetary gear mechanism 70. That is, as the carrier 73 of the first planetary gear mechanism 70 rotates, the sun gear 81 rotates at the same rotational speed as the carrier 73 of the first planetary gear mechanism 70 because its rotational direction is the same as that of the carrier 73 of the first planetary gear mechanism 70. The sun tooth portion 81a has, for example, helical teeth cut at an angle relative to the axis of the sun gear 81. That is, the sun gear 81 is, for example, a helical gear.

[0100] The planetary gear 82 is, for example, an external gear in which a planetary tooth portion 82a is formed on its outer peripheral surface. The planetary tooth portion 82a has, for example, helical teeth cut at an angle relative to the axis of the planetary gear 82. That is, the 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. The sun gear 81 is positioned between the three planetary gears 82, in which the sun tooth portion 81a meshes with the corresponding planetary tooth portions 82a of the three planetary gears 82. In addition, the planetary gears 82 mesh with the internal tooth portion 47 formed on the second housing 40, as shown in FIG. Figure 5 and Figure 6 shown.

[0101] The bracket 83 has, for example, a gear holding portion 84 for holding the planetary gears 82 and an output shaft holding portion 85 for holding the output shaft 86. The gear holding portion 84 is formed, for example, in a cylindrical shape, in which three receiving openings 84a for receiving the planetary gears 82 are formed in the outer peripheral surface of the bracket. Each of the planetary gears 82 is rotatably attached to the corresponding receiving opening 84a by a pin 87 facing the axial direction, as shown in FIG. Figure 3 As shown. The planetary gear 82 is attached in a state where a portion of the planetary tooth portion 82a protrudes from the outer peripheral surface of the bracket 83. This makes it possible for the planetary tooth portion 82a to mesh with the internal tooth portion 47 formed on the second housing 40. In addition, as Figure 8 As shown, the output shaft holding portion 85 is formed as a cylinder having a diameter smaller than that of the gear holding portion 84 , and a fitting hole 85 a for holding the output shaft 86 is formed in a central portion of the output shaft holding portion 85 .

[0102] The output shaft 86 is held on the bracket 83, for example, and rotates together with the bracket 83. The output shaft 86 has an output gear 86a having knurled teeth on the shaft. That is, the output shaft 86 is configured as a gear having knurled teeth, for example.

[0103] (Operation of Actuator 1)

[0104] An example of the operation of the actuator 1 will be described below. First, when Figure 4 When the motor 10 is operated, the rotating shaft 12 rotates in a first direction or a second direction. The following description will be directed to the case where the rotating shaft 12 rotates in the first direction.

[0105] It should be noted that, relative to the rotation direction of each component in the components, the first direction is when Figure 1 The second direction is the clockwise direction when viewing all components from the direction indicated by the arrow AII shown in FIG. Figure 2The direction indicated by the arrow AII shown is counterclockwise when viewing all components.

[0106] When the rotation shaft 12 rotates in the first direction, the sun gear 71 (in Figure 3 and Figure 7 As the rotation shaft 12 rotates, the sun gear 71 rotates in the first direction. 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, their rotation in the second direction causes them to rotate (orbit) around the axis of the first planetary gear mechanism 70 in the first direction. As the planetary gears 72 rotate (orbit), the carrier 73 rotates in the first direction about its own axis.

[0107] Thus, when the bracket 73 rotates in the first direction, the sun gear 81 (in Figure 3 and Figure 8 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. In addition, because the planetary gears 82 mesh with the inner tooth portion 47, as shown in FIG. Figure 5 and Figure 6 As shown, the planetary gears 82 rotate in the second direction, causing them to rotate (orbit) in the first direction about the axis of the second planetary gear mechanism 80. As the planetary gears 82 rotate (orbit) in the first direction, the carrier 83 rotates in the first direction about its own axis. This rotation of the carrier 83 is transmitted to the output shaft 86 held on the carrier 83.

[0108] While the above description is of the case where the rotating shaft 12 rotates in the first direction, the description of the operation of the actuator 1 will be the same if the rotating shaft 12 rotates in the second direction, where only the rotation direction of each of the gears is opposite.

[0109] As described above, the second housing 40 and the internal gear 74 are physically separated. In addition, when the actuator 1 is not in operation, a gap is formed between the second housing 40 and the internal gear 74. In view of this, when the actuator 1 is in operation, the internal gear 74 can rotate around the axis of the second housing 40 or move in a direction perpendicular to the axis by an amount equivalent to the provided gap. For example, when the internal gear 74 is moved from Figure 9 When the state shown is rotated in the first direction (clockwise), each of the plurality of movement limiting projections 75 formed on the internal gear 74 will soon come into line contact with the corresponding stopper 45 formed on the second housing 40, as shown in FIG. Figure 12As shown. As a result, the internal gear 74 will not be able to rotate further in the clockwise direction. Because the stoppers 45 are formed in pairs, even if the internal gear 74 rotates in the second direction (counterclockwise), the rotation of the internal gear 74 around the axis will be restricted by the same line contact.

[0110] In addition, the internal gear 74 is Figure 9 The state shown is moving in a direction perpendicular to the axis, for example, moving upward in the figure. Figure 13 As shown, the movement limiting protrusion 75 formed on the internal gear 74 in the upper part of the figure is in line contact with the stopper 45 pair formed on the second housing 40. As a result, the internal gear 74 will not be able to move further in the upward direction, and the movement in the direction perpendicular to the axis will be restricted. In addition, in this case, the top 75b of the internal gear 74 (more specifically, the top 75b of the movement limiting protrusion 75) will not contact the second housing 40 (or more specifically, the inner wall 44a of the cylinder 44). It should be noted that in the case where 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 stopper 45 pairs are arranged at equal intervals in the circumferential direction, they are able to limit the movement of the internal gear 74 in various directions (such as Figure 9 Movement in the vertical, horizontal and diagonal directions).

[0111] (Effect)

[0112] In view of the above embodiment, even in the structural unit in which the internal gear 74 and the second housing 40 are separated, the internal gear 74 will move during operation of the actuator 1, the stopper 45 and the movement limiting protrusion 75 will make line contact, thereby limiting the movement of the internal gear 74. Figure 12 The figure shows the line contact state between the internal gear 74 and the second housing 40 by the rotation of the internal gear 74 around the axis. In this case, the stopper 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, the reference Figure 12An enlarged view in is used to illustrate a single contact position in which the contact is at the top of the figure. As shown in the figure, the contact position between the connecting portion 45b of the stopper 45 (shown by a bulging convex curve) and the inclined edge portion 75a of the movement limiting protrusion 75 (shown by a straight line) can be depicted as a contact point P1. That is, the contact will be within an extremely limited range. It should be noted that the cross-section of the second housing 40 and the cross-section of the internal gear 74 have a constant shape and size 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 that has no curvature in a direction parallel to the axis and a plane parallel to the axis. Therefore, the contact between the internal gear 74 and the second housing 40 will be a line contact along the axial direction parallel to the X-axis, and Figure 14 The contact area 90 shown is the same.

[0113] also, Figure 13 1 and 2 show a state of contact between the second housing 40 and the internal gear 74 by movement of the internal gear 74 in a direction perpendicular to the axis (eg, movement in an upward direction in the figure). Figure 13 As shown, the contact positions between the second housing 40 and the internal gear 74 are four positions indicated by contact points P2 to P5. Figure 13 As shown in the enlarged view in FIG, contact points P2 and P3 are the contact locations between the connecting portion 45b of the stopper 45 (indicated by a raised convex curve) and the inclined edge portion 75a of the movement-limiting protrusion 75 (indicated by a straight line). In the same manner as described above, such contact locations are linear contacts between the two, assuming that they are contact between a convex surface that does not curve in a direction parallel to the axis and a flat surface parallel to the axis. Furthermore, the contact between the stopper 45 and the movement-limiting protrusion 75 at contact points P4 and P5 will also be linear contacts, as they are contact between a convex surface and a flat surface.

[0114] Thus, by providing a pair of stoppers 45 having a herringbone shape (with convexly curved surfaces) and configured to facilitate insertion of the triangular movement-limiting projection 75 (with a flat, inclined surface) therebetween, it is possible to achieve line contact between the internal gear 74 and the second housing 40, even when the internal gear 74 is rotating about the axis and even when the internal gear is moving in a direction perpendicular to the axis. Because the contact area between the internal gear 74 and the second housing 40 is small (in this manner, line contact is achieved), vibration transmitted from the internal gear 74 to the second housing 40 during operation is reduced. Vibration of the second housing 40 generated by transmission from the first planetary gear mechanism 70 is thereby suppressed, thereby making it possible to suppress noise generated from the planetary gear device 20 accompanying vibration caused by the first planetary gear mechanism 70.

[0115] Note that "line contact" described in this specification is a contact state in which the contact portion forms a line, and does not only indicate a contact state to be shown by a single point or a plurality of points as a contact point in each individual cross section, but also indicates a contact state as shown in FIG. Figure 14 As shown, it includes a contact state in a form in which the width W is considered to be sufficiently small when compared with the length L in the contact area 90. In addition, the "line contact" used in this specification also includes a contact state in which the contact is discontinuous (sporadic contact) so that when an imaginary line is drawn in the axial direction, the width W in the contact area 90 will form a line. In addition, the "line contact" used in this specification also includes a contact state in which the width W in the contact area 90 forms a line that describes an angled line rather than a line in the axial direction. In addition, the "line contact" used in this specification also includes a contact state in which the contact is discontinuous (sporadic contact) so that when an imaginary line is drawn as an angled line rather than in the axial direction, the width W in the contact area 90 will form a line.

[0116] Although in the above embodiment, the description describes a form in which the first convex portion and the second convex portion are in line contact, the present invention is not limited to this. Instead, the contact method can be appropriately selected according to the form and can be a form in which there is point contact or a form in which there is surface contact between the first convex portion and the second convex portion.

[0117] In addition, if Figure 11 As shown, the cross section of the movement limiting protrusion 75 taken by a plane perpendicular to the axis is triangular to configure an outward-facing top 75b (which is narrow at the top end) to allow the internal gear 74 to be easily removed from the mold during injection molding. This can improve production yield.

[0118] In addition, if Figure 15 As shown, in a cross section taken by a plane perpendicular to the axial direction, the movement limiting projection 75 is formed with straight inclined edge portions 75a on both sides. Figure 15 A movement limiting protrusion 100 is shown as a reference example of the movement limiting protrusion 75, and the shape of the movement limiting protrusion 100 is shown by a double-dotted dashed line, in which both sides are bulged. Comparing the two, the cross-sectional area of ​​the movement limiting protrusion 75 is reduced by an amount equivalent to the area of ​​the region indicated by the hatched line compared to the cross-sectional area of ​​the movement limiting protrusion 100. In view of this, the present embodiment is able to reduce the load on the motor 10 by reducing the weight of the internal gear 74, and also reduce manufacturing costs. In addition, since the weight of the operating internal gear 74 is reduced, the present invention can reduce (suppress) the impact when the internal gear 74 contacts the second housing 40, thereby also reducing (suppressing) the vibration of the second housing.

[0119] Furthermore, the internal gear 74 is formed of a synthetic resin having a lower hardness than the synthetic resin used to form the second housing 40. From the perspectives of mechanical strength, wear resistance, thermal durability, and the like, it is preferable that engineering plastics or super engineering plastics be used as the synthetic resin used to form the internal gear 74 and the second housing 40. Examples of such synthetic resins include ultra-high-density polyethylene (UHPE), polyphenylene sulfide (PPS), polyarylate (PAR), polyoxymethylene (POM), polyamide (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyethersulfone (PES), and polyetheretherketone (PEEK).

[0120] The synthetic resins used to form the internal gear 74 and the second housing 40 may be the same material or different materials, and may be appropriately selected within the range of producing the effects of the present invention.

[0121] Among the above-mentioned synthetic resins, relatively soft synthetic resins suitable for forming the internal gear 74 are preferably used, for example, ultra-polymer polyethylene (UHPE), polyphenylene sulfide (PPS), polyarylate (PAR), polyoxymethylene (POM), or polyamide (PA). In addition, relatively hard synthetic resins suitable for forming the second housing 40 are preferably used, for example, polycarbonate (PC), polybutylene terephthalate (PBT), polyethersulfone (PES), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyoxymethylene (POM), or polyamide (PA). In addition, when a synthetic resin material having the same main component is used to form the internal gear 74 and the synthetic resin material used for the second housing 40, it is preferred that the synthetic resin used to form the second housing 40 be harder by changing, for example, the density of the synthetic resin.

[0122] By forming the internal gear 74 from a synthetic resin having a lower hardness than the second housing 40, the impact when the internal gear 74 contacts the second housing 40 can be reduced, thereby reducing (suppressing) the vibration generated in the second housing 40. In this way, the present invention can reduce (suppress) the noise caused by the vibration of the second housing 40, and further reduce (suppress) the noise when the internal gear 74 collides with the second housing 40. Therefore, the noise generated from the planetary gear device 20 due to the vibration caused by the first planetary gear mechanism 70 can be suppressed.

[0123] Furthermore, in this embodiment, the structure in which the housing and internal gear are separated is only applied to the first-stage planetary gear mechanism, which rotates at high speed, and not to the second-stage planetary gear mechanism, which rotates at low speed. That is, in this embodiment, the structure in which the internal gear is floating is used in a mechanism that rotates at high speed and tends to generate large vibrations and noise, while the structure in which the housing forms the internal gears is used in a mechanism that rotates at low speeds and tends to generate relatively low vibrations and noise. In this way, this embodiment not only suppresses the vibrations and noise caused by the planetary gear mechanism in the planetary gear device, but also prevents the number of components in the planetary gear device from increasing beyond necessity, and prevents increases in assembly work and assembly costs. Consequently, it is possible to reduce the manufacturing costs of the planetary gear device. In this way, two mechanisms with different structures can be employed, depending on the rotational form of the planetary gear mechanism, and these two mechanisms can be used in parallel.

[0124] (Modified embodiment)

[0125] The present invention is not limited to the above-described embodiment, but can be modified and applied in various ways. In the above-described embodiment, the pair of stoppers 45 is provided in the second housing 40, and the movement-limiting projection 75 inserted between the pair of stoppers 45 is provided on the internal gear 74. However, the present invention is not limited to this, and the positions in which the pair of stoppers 45 and the movement-limiting projection 75 are provided may be switched so that the movement-limiting projection 75 is provided on the inner peripheral surface of the second housing 40 and the pair of stoppers 45 is provided on the outer peripheral surface of the internal gear 74.

[0126] Although the cross-section of the pair of stoppers 45 is a herringbone shape 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 pair of stoppers is triangular and the cross-section of the movement limiting protrusion inserted between the stoppers is a herringbone shape.

[0127] Furthermore, there is no particular limitation on the number of positions at which pairs of stoppers 45 and corresponding movement restricting projections 75 are provided, and the number may be a larger number of positions or a smaller number of positions than the six positions given in the above embodiment.

[0128] Furthermore, although the convex curved surfaces of the pair of stoppers 45 are caused to contact the plane of the movement-limiting protrusion 75 to cause line contact therebetween, line contact may be achieved by causing contact of other shapes. Figure 16 Another embodiment of achieving line contact is described below. Figure 9 The difference in the structure shown in the enlarged view of FIG is that the cross section of the movement limiting protrusion (first protrusion) 175 is not a triangular cross section, but a rounded herringbone shape. Figure 9The same structure is shown in the enlarged view in Figure 16 , when the actuator is not operating, the internal gear 174 is indicated by a solid line. In addition, the internal gear 174 shown by the double-dashed line is in a state where it has been moved upward to contact the second housing 40 by the operation of the actuator. Figure 16 As shown, the contact between the pair of stoppers 45 and the movement-limiting protrusion 175 is contact between convex curved surfaces, and thus line contact occurs at contact points P6 and P7 between the pair of stoppers 45 and the movement-limiting protrusion 175. Thus, in this embodiment, line contact is achieved by causing the bulging convex curved surfaces to contact each other.

[0129] Furthermore, there is no limitation to this, wherein line contact can be achieved by the second housing 40 having a partially concave part with a large curvature, the internal gear 74 having a convex surface with a smaller curvature, wherein the concave surface with a high curvature contacts the convex surface of the bulge. The actual structure for achieving line contact is arbitrary.

[0130] Note that, in another example for achieving the above-described line contact, the configuration of the internal gear in the position for making line contact may be exchanged with the configuration of the second housing.

[0131] Furthermore, although the actuator 1 is provided with a two-stage planetary gear mechanism consisting of the first planetary gear mechanism 70 and the second planetary gear mechanism 80, the number of stages as a speed reduction mechanism for reducing the rotation of the motor 10 can be arbitrarily set. For example, the speed reduction ratio can be increased by providing a three-stage or more-stage planetary gear mechanism, or the structure can include only a single-stage planetary gear mechanism.

[0132] Furthermore, in the above-described embodiment, a configuration is employed in which a structure in which the housing and the internal gear are separated is applied only to the first planetary gear mechanism 70, which is a first-stage mechanism rotating at high speed, and a housing having 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, a structure in which the housing and the internal gear are separated can also be employed in the second planetary gear mechanism 80, which is a second-stage mechanism, to achieve reductions in vibration and noise.

[0133] In addition, although the above embodiment describes 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 is not limited to the present application. Figure 8 The component shown provided with the output shaft 86 can be used as the input side and connected to the rotating shaft of the motor, and Figure 7 The part shown with the sun gear 71 can be used as the output side and connected to the output shaft. This will increase and output the rotation of the motor to act as a speed increasing mechanism. In this case, due to Figure 7The high-speed operation of the first planetary gear mechanism 70 shown in FIG. 1 also preferably adopts a structure in which the internal gear and the housing are separated. In addition, since the rotation of the motor is directly transmitted to the Figure 8 The second planetary gear mechanism 80 shown is therefore preferably configured such that the internal gear and the housing are separated as required.

[0134] When using the present invention in various applications, when a planetary gear mechanism is provided with three or more stages, a separate structural unit for the internal gear and housing is used for the planetary gear mechanism operating at the highest speed. This effectively reduces the vibration and noise generated. Furthermore, since the planetary gear mechanism operating at the lowest speed generates minimal vibration and noise, a structure equipped with a housing having internal teeth formed on the inner peripheral surface is employed. This eliminates the need for an unnecessary separate structure for the internal gear and housing, thereby avoiding an increase in the number of components, as well as an increase in assembly work and costs, thereby suppressing production costs.

[0135] Furthermore, while the embodiment described above is directed to a case where each of the gears used to transmit power from the motor 10 to the 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 greater backlash at the point where the teeth mesh compared to when helical gears are used, even in this case, the structure of the present invention can be used to reduce (suppress) vibration and noise in the planetary gear device.

[0136] (Modified embodiment of internal gear)

[0137] <Internal Gear Modification Example 1>

[0138] FIG. 17 is a diagram accompanying the description of a first modified example of the internal gear 74 according to the embodiment of the present invention, wherein Figure 17A is a rear view of the internal gear 74A as a first modified example, and Figure 17B : is a right side view of the internal gear 74A. Figure 17A and Figure 17B As shown, when compared with the internal gear 74, the internal gear 74A differs only in the shape of the contact protrusion portion 742A.

[0139] The contact projection portion 742A is formed in a square pyramid shape that projects to the contact surface portion 411 side in the end surface (open end surface) 740A on the side of the internal gear 74A that contacts the contact surface portion 411 (the other side in the axial direction) of the second housing 40, and has a top of a tip portion on the contact surface portion 411 side. Figure 18A As shown, the contact protrusion 742A is formed to have a point so that the tip that contacts the contact surface portion 411 (i.e., the top of 742A) is pointed. In this way, as shown in FIG. Figure 18B As shown, when compared with contact protrusion 742 in which the tip of contact protrusion 742A is rounded, even if the contact protrusion is deformed, the area of ​​contact with the contact surface can be reduced. In this way, contact protrusion 742A can transmit vibration occurring on the side of internal gear 74A (i.e., one side in the axial direction) to the other side in a state where the vibration is more suppressed than in the case of contact protrusion 742.

[0140] <Internal Gear Modification Example 2>

[0141] FIG. 19 is a diagram accompanying the explanation of a second modified example of the internal gear 74 according to the embodiment of the present invention, wherein Figure 19A is a rear view of the internal gear 74B as a second modified example, and Figure 19B This is a right side view of the internal gear 74B. Compared to the internal gear 74, the shape of the contact projection 742B in the internal gear 74B is different. The contact projection 742B is formed into a triangular pyramidal shape that projects toward the contact surface 411 (the other side in the axial direction) of the end surface (open end surface) 740B on the side of the internal gear 74B that contacts the contact surface 411 of the second housing 40, and has a top portion at a tip portion on the contact surface 411 side. This produces a similar effect in operation as in Modification Example 1.

[0142] <Internal Gear Modification Example 3>

[0143] FIG. 20 is a diagram accompanying the explanation of a third modified example of the internal gear 74 according to the embodiment according to the present invention, wherein Figure 20A is a rear view of an internal gear 74C as a third modified example, and Figure 20B This is a right side view of the internal gear 74C. Compared to the internal gear 74, the internal gear 74C differs only in the shape of the contact projection 742C. The contact projection 742C is formed into a conical shape that projects toward the contact surface 411 (the other side in the axial direction) of the end face (open end face) 740C on the side of the internal gear 74C that contacts the contact surface 411 of the second housing 40, and has a tip portion on the contact surface 411 side. This produces a similar effect in operation as in Modified Example 1.

[0144] <Internal Gear Modification Example 4>

[0145] FIG. 21 is a diagram accompanying the explanation of a fourth modified example of the internal gear 4 according to the embodiment according to the present invention, wherein Figure 21A is a rear view of an internal gear 74D as a fourth modified example, and Figure 21B 74D is a right side view of the internal gear 74D. When compared with the internal gear 74, the internal gear 74D differs only in the shape of the contact projection 742D.

[0146] The contact projection 742D is formed in a rod-shaped body that protrudes from an end face (open end face) 740D on one side of the internal gear 74D that contacts the contact surface portion 411 (the other side in the axial direction) of the second housing 40, toward the contact surface portion 411 side, with the tip of the 742D being rounded into a spherical surface shape. Specifically, the contact projection 742D has a rod-shaped extension and a hemispherical surface portion provided at the tip of the extension. In this case, the tip has a hemispherical surface shape and thus makes point contact with the contact surface 411 portion. This can even further suppress the transmission of vibration from the internal gear 74D side to the second housing 40.

[0147] <Internal Gear Modification Example 5>

[0148] FIG. 22 is a diagram accompanying the description of a fifth modified example of the internal gear 74 according to the embodiment according to the present invention, wherein Figure 22A is a rear view of an internal gear 74E as a fifth modified example, and Figure 22B This is a right side view of the internal gear 74E. Compared to the internal gear 74, the internal gear 74E differs only in the shape of the contact projection 742E. The contact projection 742E is formed on the end face (open end face) 740E on the side of the internal gear 74E that contacts the contact surface 411 (the other side in the axial direction) of the second housing 40. This contact projection 742E protrudes toward the contact surface 411 and has a "+" shape when viewed from the back. The tip of the contact projection 742E is formed into a sharp shape, thereby making point contact with the contact surface 411.

[0149] When compared with the contact protrusions 742A to 742C having a pyramid or cone shape, and when compared with the contact protrusion 742D having a rod shape, the area of ​​the contact protrusion 742E in the cross section perpendicular to the axial direction (i.e., the area for propagating vibration in the axial direction) is smaller. This can even further suppress the transmission of vibration from one side to the other in the axial direction.

[0150] <Internal Gear Modification Example 6>

[0151] FIG. 23 is a diagram accompanying the explanation of a sixth modified example of the internal gear 74 according to the embodiment according to the present invention, wherein Figure 23Ais a rear view of an internal gear 74F as a sixth modified example, and Figure 22B 23 is a right side view of the internal gear 74F. When compared with the internal gear 74, the internal gear 74F shown in FIG23 is different only in the shape of the contact projection 742F.

[0152] The contact projection 742F is provided on the end surface (open end surface) 740F of the internal gear 74F on the side that contacts the contact surface 411 (the other side in the axial direction) of the second housing 40, so as to protrude toward the contact surface 411 side, and the shape of the cross section perpendicular to the axial direction forms a "+" (plus sign). The outer shape of the contact projection 742F is curved so as to protrude toward the tip, so that the curved tip portion makes point contact with the contact surface 411.

[0153] When compared with the contact protrusions 742A to 742C having a pyramidal or conical body, and when compared with the contact protrusion 742D having a rod shape, the area of ​​the contact protrusion 742F in the cross section perpendicular to the axial direction (i.e., the area for propagating vibration in the axial direction) is smaller. This can further suppress the transmission of vibration from one side to the other in the axial direction.

[0154] <Internal Gear Modification Example 7>

[0155] FIG. 24 is a diagram accompanying the description of a seventh modified example of the internal gear 74 according to the embodiment according to the present invention, wherein Figure 24A is a rear view of an internal gear 74G as a seventh modified example, and Figure 24B 7 is a right side view of the internal gear 74G. Compared to the internal gear 74, the internal gear 74G differs only in the shape of the contact projection 742G. The contact projection 742G is formed in an end surface (open end surface) 740G on the side of the internal gear 74G that contacts the contact surface 411 (the other side in the axial direction) of the second housing 40, thereby projecting toward the contact surface 411.

[0156] The contact protrusion 742G is an arched plate-shaped body that protrudes to the other side and is curved so that the center of the tip surface is the top. In other words, the tip portion of the contact protrusion 742g is formed into a spherical surface shape. The contact protrusions 742g are arranged parallel to each other on the end surface 740G, with a specified distance between them in the circumferential direction.

[0157] When compared with the contact protrusions 742A to 742C having a pyramid or cone shape, and when compared with the contact protrusion 742D having a rod shape, the area of ​​the contact protrusion 742G in the cross section perpendicular to the axial direction (i.e., the area for propagating vibration in the axial direction) is smaller. This can even further suppress the transmission of vibration from one side to the other in the axial direction.

[0158] <Internal Gear Modification Example 8>

[0159] FIG. 25 is a diagram accompanying the description of an eighth modified example of the internal gear 8 according to the embodiment of the present invention, wherein Figure 25A is a rear view of an internal gear 74H as an eighth modified example, and Figure 24B 74H is a right side view of the internal gear 74H. In the internal gear 74H, the direction of the contact projection 742G in the structure of the internal gear 74G is changed.

[0160] Specifically, the shape of the contact protrusion portion 742H of the internal gear 74H is the same as the shape of the contact protrusion portion 742G, so that the end face (open end face) 740H on one side (the other side in the axial direction) of the internal gear 74H that contacts the contact surface portion 411 of the second shell 40 protrudes to the contact surface portion 411.

[0161] The contact protrusion portions 742H are arched plate-shaped portions that protrude to the other side and are provided at prescribed intervals in the circumferential direction on the end surface 740H, with the corresponding flat portions (e.g., back surfaces) being provided so as to face the axis of the second housing 40. This can even further suppress the transmission of vibration from the internal gear 74H to the second housing 40 side.

[0162] Furthermore, in the contact projection 742H, each flat portion of the end surface 740H (and specifically, the inner surface 7421 on the axis side) is arranged in a circumferentially aligned state. The internal gear 74H is configured to achieve circumferential floating movement within the second housing 40, wherein the interior of the second housing 40 is coated with a lubricant (such as grease) on the portion that slides with the internal gear 74H. When the lubricant is applied to the internal gear 74H within the second housing 40, even when the internal gear 74H moves circumferentially, the lubricant tends to remain circumferentially on the inner surface 7421, thereby allowing the internal gear 74H to maintain its floating state well within the second housing 40.

[0163] <Internal Gear Modification Example 9>

[0164] FIG. 26 is a diagram accompanying the description of a ninth modified example of the internal gear 9 according to the embodiment of the present invention, wherein Figure 26A is a rear view of the internal gear 74I as a ninth modified example, and Figure 26B 74I is a right side view of the internal gear 74I. In the internal gear 74I, the direction of the contact projection 742G in the structure of the internal gear 74G is changed.

[0165] Specifically, the shape of the contact protrusion portion 742I of the internal gear 74I is the same as the shape of the contact protrusion portion 742G, so that the end face (open end face) 740I on one side (the other side in the axial direction) of the internal gear 74I that contacts the contact surface portion 411 of the second shell 40 protrudes to the contact surface portion 411.

[0166] The contact protrusions 742I are arched plate-shaped portions that protrude to the other side and are arranged at regular intervals in the circumferential direction on the end surface 740I, with corresponding flat portions (e.g., the back surface) being arranged in a radial shape in the radial direction of the second housing 40. This can even further suppress the transmission of vibration from the internal gear 74I to the second housing 40 side.

[0167] <Internal Gear Modification Example 10>

[0168] Although six contact projections 742 and 742A to 742I are provided at a time in each of the embodiments and the modified examples of Examples 1 to 8 described above, with equal spacing between them in the circumferential direction on the corresponding end faces (opening end faces) 740 and 740A to 740I, any number thereof may be provided. For example, as shown with respect to the internal gear 74J depicted in FIG27 , three contact projections 742J may be provided so as to protrude from the end face (opening end face) 740J on one side (the other side in the axial direction) of the contact surface portion 411 of the second housing 40, with spaces therebetween in the circumferential direction. The contact projections 742J are not limited to being in the same shape as the contact projections 742J shown in FIG27 , but may be provided in the same shape as any one of the contact projections 742A to 742I.

[0169] As described with respect to the internal gear 74J, the smaller the contact protrusions 742J provided on the end surface 740J, the smaller the propagation path of vibration to the contact surface portion 411, thereby being able to suppress the transmission of vibration from the internal gear 74J side to the second housing 40. Furthermore, although the contact protrusions 742 and 742A to 742J in the internal gears 74 and 74A to 74J are each configured to be arranged at equal intervals therebetween in the circumferential direction on the respective end surfaces 740 and 740A to 740J, there is no limitation thereto.

[0170] <Internal Gear Modification Example 11>

[0171] In an internal gear 74K, as an eleventh modified example of the internal gear 74 shown in FIG. 28 , contact projections 742K protrude to the other side with unequal spacing therebetween in the circumferential direction on an end surface (opening end surface) 740K. While the contact projections 742K are formed into a hemispherical shape (similar to the contact projections 740) in the internal gear 74K of the eleventh modified example, there is no limitation thereto, and the shape may be the same as that of any of the contact projections 742A to 742I of the internal gears 74A to 74I.

[0172] <Internal Gear Modification Example 12>

[0173] Compared to the internal gear 74, the internal gear 74L, as shown in FIG. 29 as a 12th modified example of the internal gear 74, is provided with a contact protrusion 742L on the end face 740L on the other side, and an end face on the other side (opening end face) 741L on the side opposite to the end face 740L. The contact protrusions 742L are provided so as to protrude in a plurality on both end faces 740L and 741L with a prescribed spacing therebetween (in this embodiment, equal spacing) in the circumferential direction. That is, the internal gear 74L is provided with a contact protrusion (contact portion on one side) that protrudes on the end face (opening end face) 741L on one side in the same manner as the contact protrusion 742L.

[0174] The internal gear 74L makes point contact with the contact surface 411 portion of the second housing 40 through the contact projection 742L on the end surface 740L on the other side, and makes point contact with the first housing 30 through the contact projection 742L on the end surface 741L on one side.

[0175] Thus, in an actuator in which the internal gear 74L is also connected to the motor side by point contact, the transmission of vibration to the housing and the motor can be suppressed. Note that this configuration in which the contact projections are provided on the two open end faces separated in the axial direction of the internal gear 74 can be applied to any of the internal gears 74A to 74K of various Modifications 1 to 11, and in addition to the various effects described above, effects similar to those of the internal gear 74L can be produced in operation.

[0176] With respect to the internal gears 74, 74A to 74C, and 74E to 74L shown in the present embodiment and in modified examples 1 to 12, the contact protrusions 742, 742A to 742C, and 742E to 742L are formed so that the area of ​​the cross section perpendicular to the axial direction becomes smaller toward the protruding direction. That is, in addition to the contact protrusions 742, 742A to 742C, and 742E to 742L being configured so that the area of ​​the cross section perpendicular to the axial direction becomes smaller as the contact protrusions 742, 742A to 742C, and 742E to 742L become smaller as the contact protrusions 742, 742A to 742C, and 742E to 742L are further away from the end surface (opening end surface) 740, 740A to 740C, and 740E to 740L on the other side, the internal gears 74, 74A to 74C, and 74E to 74L are held within the first housing 30 and the second housing 40 in a state where the corresponding contact protrusions 742, 742A to 742C, and 742E to 742L are in point contact with the contact surface portion 411. This makes it possible to suppress transmission of vibration from the internal gears 74 , 74A to 74C, and 74E to 74L to the first housing 30 and the second housing 40 through the contact surface portion 411 .

[0177] Furthermore, although the description is directed to a case in which a separate structural unit for an internal gear and a housing is used for a part of a planetary gear device, the present application is not limited thereto, but may be used as a part of another gear mechanism.

[0178] In the above embodiment, the planetary gear mechanism of the planetary gear device is implemented by 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 a plurality of (other than three) planetary gears.

[0179] Furthermore, the planetary gear device to which the present invention is applied can be applied to various machines and equipment using a speed reduction mechanism or a speed increase mechanism, such as automobiles, robots, industrial equipment, amusement park equipment, and the like.

[0180] Furthermore, instead of the structure in which the movement within the housing is restricted by producing line contact in the axial direction between the movement-restricting protrusion (first protrusion) and the pair of stoppers (second protrusion) in the above-described embodiment, the structure may be a structure in which the movement within the housing is restricted by point contact between the movement-restricting protrusion (first protrusion) and the pair of stoppers (second protrusion). More specifically, Figure 5 The stopper pair (second protruding portion) 45 in the embodiment may have a discontinuous shape in the axial direction, and Figure 7 The movement restricting protrusion portion (first protrusion portion) 75 in FIG. 1 may have a shape that is discontinuous in the axial direction.

[0181] [Explanation of Reference Symbols]

[0182] 1: Actuator

[0183] 10: Motor

[0184] 11: Motor host

[0185] 12: Rotation axis

[0186] 20: Planetary gear unit

[0187] 30: First shell

[0188] 30a: Opening

[0189] 40: Second shell

[0190] 41: First position

[0191] 42: Second position

[0192] 43: Third position

[0193] 43a: Opening

[0194] 44: Cylinder

[0195] 44a: Inner wall

[0196] 45: Stopper (second raised portion)

[0197] 45a: Upright part

[0198] 45b: Connecting part

[0199] 45c: Top

[0200] 46: Cylinder

[0201] 47: Inner tooth part

[0202] 50: Shell

[0203] 60: Planetary gear mechanism

[0204] 70: First planetary gear mechanism

[0205] 71: Sun gear

[0206] 71a: Sun gear part

[0207] 72: Planetary gear

[0208] 72a: Planetary gear part

[0209] 73: Bracket

[0210] 73a: Accommodating opening

[0211] 74, 74A, 74B, 74C, 74D, 74E, 74F, 74G, 74H, 74I, 74J, 74K, 74L: internal gear

[0212] 74a: Internal tooth part

[0213] 74b: Outer peripheral surface

[0214] 75: Movement limiting raised portion (first raised portion)

[0215] 75a: Slanted edge portion

[0216] 75b: Top

[0217] 75c: Notch

[0218] 76: Sales

[0219] 80: Second planetary gear mechanism

[0220] 81: Sun gear

[0221] 81a: Sun gear part

[0222] 82: Planetary gear

[0223] 82a: Planetary gear part

[0224] 83: Bracket

[0225] 84: Gear holding part

[0226] 84a: Accommodating opening

[0227] 85: Output shaft holding part

[0228] 85a: Mounting hole

[0229] 86: Output shaft

[0230] 86a: Output gear

[0231] 87: Sales

[0232] 90: Contact area

[0233] 140: Second shell

[0234] 141: Concave parts

[0235] 174: Internal gear

[0236] 175: Movement limiting protrusion (first protrusion)

[0237] 411: Contact surface part

[0238] 740, 740A, 740B, 740C, 740D, 740E, 740F, 740G, 740H, 740I, 740J, 740K, 740L: Open side

[0239] 742, 742A, 742B, 742C, 742D, 742E, 742F, 742G, 742H, 742I, 742J, 742K, 742L: Contact raised portion

[0240] 7421: Inner surface

Claims

1. A device for suppressing noise generated in a planetary gear device, characterized in that include: an internal gear having: an inner peripheral surface having an inner tooth portion formed thereon; wherein the internal gear has an outer peripheral surface having a convex portion formed on at least a portion thereof in a direction from one side to the other side in an axial direction of the internal gear, and wherein the internal gear has an open end surface extending between the inner peripheral surface and the outer peripheral surface at an end portion located on the other side of the internal gear; as well as a substantially cylindrical housing for accommodating the internal gear, wherein movement of the internal gear in a circumferential direction within the housing is restricted by contact with the raised portion of the internal gear, wherein the housing has a contact surface portion provided to face the opening end surface on the other side of the internal gear, and The opening end face on the other side of the internal gear has a contact portion located on the opening end face and protruding toward the contact surface portion side, wherein the contact portion includes an arched plate-shaped body protruding from the opening end face, and the arched plate-shaped body is formed with a flat portion extending in the axial direction, wherein the contact portion limits the movement of the internal gear toward the contact surface portion side by contacting the contact surface portion in the axial direction.

2. The device according to claim 1, characterized in that The contact portion includes at least three contact protrusion portions that make point contact with the contact surface portion.

3. The device according to claim 1, characterized in that The contact portion includes a plurality of contact portions protruding from the contact surface portion side, and wherein the plurality of contact portions are provided on the opening end surface at equal intervals in the circumferential direction.

4. The device according to claim 1, characterized in that The contact portion includes a plurality of contact portions protruding from the contact surface portion side, and wherein the plurality of contact portions are spaced apart on the opening end surface at unequal intervals in the circumferential direction.

5. The device according to any one of claims 1 to 4, characterized in that The contact portion is configured such that the further a cross section thereof perpendicular to the axial direction is from the opening end surface on the other side, the smaller the area of ​​the cross section becomes.

6. The device according to any one of claims 1 to 4, characterized in that The second contact portion is provided on a second opening end face of the internal gear, the second opening end face extending between the inner peripheral surface and the outer peripheral surface on an end portion opposite to the opening end face on the other side, and the second contact portion is configured to protrude from the opening end face on the one side.

7. The device according to any one of claims 1 to 6, characterized in that The internal gear and the housing are made of synthetic resin, and The internal gear is formed of a synthetic resin having a lower hardness than the synthetic resin used to form the housing.

8. A planetary gear device, characterized in that: include: An apparatus for suppressing noise generated in a planetary gear device according to any one of claims 1 to 4; at least one planetary gear meshing with the internal gear, a sun gear meshing with the at least one planetary gear and positioned at a radial center of the housing; as well as A carrier rotatably supports the one or more planetary gears.

9. The planetary gear device according to claim 8, characterized in that Also includes: a second sun gear, the second sun gear rotating as the bracket rotates; one or more second planetary gears, the one or more second planetary gears being disposed on a periphery of the second sun gear and meshing with the second sun gear; a second bracket rotatably supporting the one or more second planetary gears; as well as A second housing, internal teeth meshing with the one or more second planetary gears being formed on an inner peripheral surface of the second housing, wherein the housing and the second housing are integrally formed.

10. A planetary gear device, characterized in that: include: At least two stages of planetary gear mechanisms, each stage of the planetary gear mechanism comprising: Sun gear; one or more planet gears arranged on a periphery of the sun gear for meshing with the sun gear; and a carrier that rotatably supports the one or more planetary gears, wherein in the at least two-stage planetary gear mechanism, the planetary gear mechanism that operates at the highest speed includes the apparatus for suppressing noise generated in a planetary gear device according to any one of claims 1 to 4, wherein the one or more planetary gears of the planetary gear mechanism are meshed with the internal gear, and Among the at least two-stage planetary gear mechanisms, the planetary gear mechanism operating at the lowest speed includes a housing, the housing including internal teeth formed on an inner peripheral surface of the housing and meshing with the one or more planetary gears of the planetary gear mechanism.

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

Images