Electric actuator

Abstract

An electric actuator is provided with: a motor; a rotating member that is driven by the motor to rotate and has a first threaded portion; a moving member having a second threaded portion that engages with the first threaded portion, the moving member moving in a predetermined direction in accordance with the rotation of the rotating member; a housing having a first cylindrical portion extending in a predetermined direction; and a path part, at least a part of which is provided in the housing. The first cylindrical portion has a thread accommodation portion that accommodates at least a portion of each of the first and second thread portions therein. The moving member protrudes from the inside of the screw accommodating portion to the outside of the screw accommodating portion through an opening portion that opens on one side in the predetermined direction. The inner surface of the screw accommodating portion has a support surface that supports the rotating member or the moving member. The path portion has at least one of a portion composed of a groove and a portion composed of a hole, and connects a space located on the other side of the moving member in the predetermined direction to an external space located on one side of the screw accommodating portion in the predetermined direction when the moving member moves in the predetermined direction.

Description

Technical Field

[0001] This invention relates to electric actuators. Background Technology

[0002] Electric actuators that convert the rotation of a motor rotor into linear motion are known (e.g., Patent Document 1).

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-17148

[0004] In the electric actuators described above, the moving component that performs linear motion is sometimes exposed in the space where the fluid is present. In this case, due to the pressure of the fluid, the torque of the motor required to move the moving component can sometimes increase. Therefore, there is a problem of increasing the size of the motor and the overall size of the electric actuator. Summary of the Invention

[0005] In view of the above circumstances, one of the objectives of this invention is to provide an electric actuator with a miniaturizable structure.

[0006] One embodiment of the electric actuator of the present invention comprises: a motor; a rotating member driven by the motor to rotate, the rotating member having a first threaded portion; a moving member having a second threaded portion engaging with the first threaded portion and moving in a predetermined direction as the rotating member rotates; a housing having a first cylindrical portion extending in the predetermined direction; and a path portion, at least a portion of the path portion being disposed in the housing. The first cylindrical portion has a threaded receiving portion that accommodates at least a portion of the first threaded portion and at least a portion of the second threaded portion internally. The threaded receiving portion has an opening on one side of the predetermined direction. The moving member protrudes from the interior of the threaded receiving portion to the exterior of the threaded receiving portion via the opening. The inner surface of the threaded receiving portion has a support surface that supports the rotating member or the moving member. The path portion has at least one of a groove portion and a hole portion, and connects a space located on the other side of the predetermined direction of the moving member when it moves in the predetermined direction to an external space located on one side of the predetermined direction of the threaded receiving portion.

[0007] According to one aspect of the present invention, electric actuators can be miniaturized. Attached Figure Description

[0008] Figure 1 This is a perspective view showing the electric actuator in the first embodiment.

[0009] Figure 2 It is a cross-sectional view showing the electric actuator in the first embodiment, and a view showing the cross-section through which the second central axis passes.

[0010] Figure 3 It is a cross-sectional view showing the electric actuator in the first embodiment, and a view showing the cross section through which the first central axis passes.

[0011] Figure 4 This is a perspective view showing the actuator section in the first embodiment.

[0012] Figure 5 This is a cross-sectional view showing a portion of the electric actuator in the first embodiment, and is Figure 3 VV sectional view.

[0013] Figure 6 This is a cross-sectional perspective view showing a portion of the electric actuator in the first embodiment.

[0014] Figure 7 This is an exploded perspective view showing the first cylindrical part, the rotating member, and the moving member in the first embodiment.

[0015] Figure 8 This is a cross-sectional view showing a portion of the electric actuator in the first embodiment, and is Figure 2 Sectional view of VIII-VIII.

[0016] Figure 9 This is an exploded perspective view showing a portion of the electric actuator in the first embodiment.

[0017] Figure 10 This is a perspective view showing the motor, pressing member, and elastic member in the first embodiment.

[0018] Figure 11 This is an exploded perspective view showing a portion of the electric actuator in the first embodiment, and is a view showing... Figure 9 Diagrams of different body parts.

[0019] Figure 12 This is a cross-sectional view showing a portion of the electric actuator in the first embodiment, and is Figure 2 Sectional view XII-XII.

[0020] Figure 13 This is a cross-sectional view showing the electric actuator in the second embodiment.

[0021] Figure 14 This is a cross-sectional view showing the electric actuator in the third embodiment.

[0022] Figure 15 This is a cross-sectional view showing a portion of the electric actuator in the fourth embodiment.

[0023] Explanation of reference numerals in the attached figures

[0024] 10, 210: Housing; 41, 241, 341: First cylindrical portion; 41a, 241a: Threaded receiving portion; 41c: Second opening (opening); 43, 243: Groove; 44, 344: Support surface; 50, 450: Motor; 52: Rotor; 52a: Motor shaft; 60: Reduction mechanism; 71, 371, 471: Rotating component; 71c, 371c: First threaded portion; 72, 372: Moving part Components; 72a: Second cylindrical portion; 72c, 372c: Second threaded portion; 80: First sealing component (sealing component); 90, 290, 390: Path portion; 91, 291: Extension path portion; 100, 200, 300, 400: Electric actuator; 241e: Small diameter portion; 241f: Large diameter portion; 371a: Third cylindrical portion; 371e: Hole; S1a: External space; S1b, S2b: Space. Detailed Implementation

[0025] The accompanying drawings conjecturely illustrate the first central axis J1 of the motor in the electric actuator of the embodiment described below. In the following description, unless otherwise specified, the axial direction of the first central axis J1 is simply referred to as "axial direction." The radial direction centered on the first central axis J1 is simply referred to as "radial direction." The Y-axis shown in each figure represents the direction in which the first central axis J1 extends. The X-axis shown in each figure represents a direction orthogonal to the Y-axis direction. The Z-axis shown in each figure represents a direction orthogonal to both the X-axis and Y-axis directions. In the following description, the direction along the X-axis is referred to as the "width direction," and the direction along the Z-axis is referred to as the "vertical direction." Furthermore, the side in the axial direction where the arrow of the Y-axis points (+Y side) is called the "axial side," and the side in the axial direction opposite to the side where the arrow of the Y-axis points (-Y side) is called the "axial side." The side in the width direction where the arrow of the X-axis points (+X side) is called the "width direction side," and the side in the width direction opposite to the side where the arrow of the X-axis points (-X side) is called the "width direction side." The side in the vertical direction where the arrow on the Z-axis points (+Z side) is called the "upper side", and the side in the vertical direction opposite to the side in the vertical direction where the arrow on the Z-axis points (-Z side) is called the "lower side".

[0026] In the following embodiments, the axial direction (Y-axis direction) corresponds to the "prescribed direction". The vertical direction (Z-axis direction) corresponds to the "first direction" that intersects the axial direction, the upper side (+Z side) corresponds to "one side of the first direction", and the lower side (-Z side) corresponds to "the other side of the first direction". The width direction (X-axis direction) corresponds to the "second direction" that is orthogonal to both the axial direction and the first direction. It should be noted that the vertical direction, width direction, upper side, and lower side are merely names used to describe the relative positional relationships of each part, and the actual configuration relationship may be other than the configuration relationship shown by these names.

[0027] <First Implementation Method>

[0028] Figure 1 The electric actuator 100 shown is a linear actuator. In this embodiment, the electric actuator 100 is an actuator capable of switching the flow path for fluid flow. The electric actuator 100 is, for example, mounted in a vehicle. Figure 1 As shown, the electric actuator 100 includes a housing 10 and an actuator section 100a. (As...) Figure 2 As shown, the electric actuator 100 includes a pressing member 55, a base plate 56, a first sealing member 80, a first spacer 81, a second spacer 82, a plate member 83, a second sealing member 84, and a third sealing member 85. Figure 3 As shown, the electric actuator 100 has an elastic member 54.

[0029] The actuator section 100a can switch the flow path (not shown) via a moving member 72 that moves linearly in the axial direction. For example... Figure 1 As shown, in this embodiment, the electric actuator 100 includes three actuator sections 100a. The three actuator sections 100a are arranged at intervals in the width direction (X-axis direction). The structures of the three actuator sections 100a are the same except for their arrangement positions. It should be noted that the number of actuator sections 100a included in the electric actuator 100 is only required to be one or more, and there is no particular limitation.

[0030] like Figure 2 As shown, the actuator section 100a includes a motor 50, a reduction gear 60, a rotating member 71, and a moving member 72. That is, the electric actuator 100 includes a motor 50, a reduction gear 60, a rotating member 71, and a moving member 72. In this embodiment, the motor 50 is an internal rotor type motor. Figure 3 As shown, the motor 50 has a motor housing 51, a rotor 52, and a stator 53.

[0031] The motor housing 51 houses the rotor 52 and stator 53 internally. For example... Figure 4As shown, the motor housing 51 has a cylindrical portion 51a, a plate-shaped portion 51b, and a supported portion 51d. The cylindrical portion 51a is cylindrical with a first central axis J1 as its center. The plate-shaped portion 51b is connected to the axial side (+Y side) of the cylindrical portion 51a. The plate-shaped portion 51b is plate-shaped with its plate surface facing axially. When viewed axially, the plate-shaped portion 51b is approximately quadrilateral. The plate-shaped portion 51b protrudes further to both sides in the width direction (X-axis direction) than the cylindrical portion 51a.

[0032] The supported portion 51d protrudes from the plate-shaped portion 51b towards one axial direction (+Y side). In this embodiment, the supported portion 51d is annular, surrounding the first central axis J1. More specifically, the supported portion 51d is annular, centered on the first central axis J1. Figure 3 As shown, the motor housing 51 has a protrusion 51c that protrudes from the other axial side (-Y side) of the cylindrical portion 51a. The protrusion 51c is a circular plate centered on the first central axis J1.

[0033] Rotor 52 rotates about a first central axis J1. Rotor 52 has a motor shaft 52a and a rotor body 52b. Motor shaft 52a extends axially. Motor shaft 52a is cylindrical and extends axially about the first central axis J1. Motor shaft 52a passes axially through the radially inner side of the supported portion 51d. Motor shaft 52a protrudes axially from the inside of motor housing 51 to the outside of motor housing 51 on one side (+Y side). The end of motor shaft 52a on the axial side is located outside motor housing 51. Rotor body 52b is fixed to the outer circumferential surface of motor shaft 52a. Although not shown in the figure, rotor body 52b has a rotor core and rotor magnets. Stator 53 is located radially outside rotor 52. Stator 53 surrounds rotor body 52b.

[0034] The reduction gear 60 is connected to the rotor 52 of the motor 50. The reduction gear 60 is located on one axial side (+Y side) of the motor 50. Figure 4 As shown, in this embodiment, the reduction mechanism 60 has a first gear portion 61 and a second gear portion 62. The first gear portion 61 rotates together with the rotor 52 about a first central axis J1. In this embodiment, the first gear portion 61 is annular, surrounding the first central axis J1. The first gear portion 61 has a plurality of teeth arranged circumferentially around the first central axis J1 on its outer peripheral surface. The portion of the motor shaft 52a located outside the motor housing 51 is fitted inside the first gear portion 61. The first gear portion 61 is fixed to the outer peripheral surface of the portion of the motor shaft 52a located outside the motor housing 51. Thus, the motor shaft 52a is connected to the reduction mechanism 60. It should be noted that the first gear portion 61 and the motor shaft 52a may also be part of the same single component.

[0035] The second gear portion 62 is located on one side (+X side) of the width direction of the first gear portion 61. The second gear portion 62 meshes with the first gear portion 61. The second gear portion 62 rotates together with the rotating member 71 about the second central axis J2. The second central axis J2 is an imaginary line extending axially from the first central axis J1. The second central axis J2 is positioned at a different radial position from the first central axis J1 centered on the first central axis J1. Figure 5 As shown, in this embodiment, the second central axis J2 is located on the side further along the width direction than the first central axis J1. The second central axis J2 is located on the lower side than the first central axis J1. Figure 6 As shown, the second gear portion 62 is annular, surrounding the second central axis J2. The outer diameter of the second gear portion 62 is larger than the outer diameter of the first gear portion 61. The second gear portion 62 has a plurality of teeth arranged circumferentially around the second central axis J2 on its outer peripheral surface. The teeth of the second gear portion 62 mesh with the teeth of the first gear portion 61.

[0036] like Figure 7 As shown, in this embodiment, the rotating member 71 is a rotating shaft extending axially. The rotating member 71 is generally cylindrical, extending axially about a second central axis J2. The rotating member 71 rotates about the second central axis J2. The rotating member 71 has a shaft body portion 71a and a supported shaft portion 71b. The shaft body portion 71a is generally cylindrical, extending axially. Figure 6 As shown, the shaft body 71a passes axially through the inner side of the second gear 62. The outer peripheral surface of the shaft body 71a is fixed to the inner peripheral surface of the second gear 62. Thus, the rotating member 71 is connected to the reduction mechanism 60. The rotation of the rotor 52 is transmitted to the rotating member 71 via the reduction mechanism 60. The rotating member 71 is driven to rotate by the motor 50.

[0037] like Figure 7 As shown, the supported shaft portion 71b is connected to the end of the shaft body portion 71a on the other axial side (-Y side). The outer diameter of the supported shaft portion 71b is smaller than the outer diameter of the shaft body portion 71a. The end of the supported shaft portion 71b on the other axial side is the end of the rotating member 71 on the other axial side. The axial dimension of the supported shaft portion 71b is smaller than the axial dimension of the shaft body portion 71a. The supported shaft portion 71b is rotatably supported on the bearing portion 21e, which will be described later.

[0038] The rotating member 71 has a first threaded portion 71c on its outer peripheral surface. The first threaded portion 71c is driven by the motor 50 to rotate about the second central axis J2. In this embodiment, the first threaded portion 71c is provided on one axial side (+Y side) of the outer peripheral surface of the shaft body portion 71a. Figure 8As shown, at least a portion of the rotating member 71 overlaps with the motor 50 when viewed axially. In this embodiment, the center of the rotating member 71 through which the second central axis J2 passes overlaps with the motor 50 when viewed axially. In this embodiment, the rotating member 71, except for the edge on the width direction side (+X side), overlaps with the motor 50 when viewed axially.

[0039] like Figure 2 As shown, the moving member 72 extends axially. The moving member 72 protrudes axially from the interior of the housing 10 to the exterior of the housing 10 via an opening on one axial side (+Y side) of the first cylindrical portion 41 (described later). The moving member 72 has a second cylindrical portion 72a and a connected portion 72b. The second cylindrical portion 72a is a cylindrical portion extending axially. The second cylindrical portion 72a opens on the other axial side (-Y side). The second cylindrical portion 72a is generally cylindrical about a second central axis J2. The second cylindrical portion 72a has a second threaded portion 72c on its inner circumferential surface. That is, the moving member 72 has a second threaded portion 72c. In this embodiment, the second threaded portion 72c is provided in a manner that extends substantially throughout the inner circumferential surface of the second cylindrical portion 72a axially. At least a portion of the rotating member 71 is located inside the second cylindrical portion 72a. In this embodiment, a portion of the rotating member 71 on one axial side is located inside the second cylindrical portion 72a. The portion of the rotating member 71 located on the other side of the axial direction is located on the other side of the axial direction than the second cylindrical portion 72a. The second threaded portion 72c provided on the inner circumferential surface of the second cylindrical portion 72a engages with the first threaded portion 71c provided on the outer circumferential surface of the rotating member 71.

[0040] The connected portion 72b is connected to one axial side (+Y side) of the second cylindrical portion 72a. A drive object driven axially by an electric actuator 100 is connected to the connected portion 72b. This drive object is, for example, a slide valve for switching a flow path (not shown). The connected portion 72b is provided with a hole 72e that connects to the interior of the second cylindrical portion 72a.

[0041] like Figure 7 As shown, a pair of planar portions 72d are provided on the outer peripheral surface of the movable member 72. The pair of planar portions 72d are arranged such that they are spaced apart from the second central axis J2 in the width direction (X-axis direction). The pair of planar portions 72d extend axially. The portion of the outer peripheral surface of the movable member 72 other than the pair of planar portions 72d is a curved surface 72f that is arc-shaped and centered on the second central axis J2 when viewed axially.

[0042] When the rotating member 71 rotates about the second central axis J2, the first threaded portion 71c rotates, and the second threaded portion 72c, which meshes with the first threaded portion 71c, feeds axially. As a result, the moving member 72 moves axially along with the rotation of the rotating member 71. Figures 1 to 3 The movable member 72 shown is in the state where it is located on the other side (-Y side) closest to the axis.

[0043] like Figure 1 As shown, the housing 10 is a generally rectangular box-shaped structure extending in the width direction (X-axis direction). The housing 10 houses a plurality of actuator parts 100a. The housing 10 has a housing body 20, a first cover 30, and a second cover 40. In this embodiment, the housing body 20, the first cover 30, and the second cover 40 are made of resin. It should be noted that the housing body 20, the first cover 30, and the second cover 40 may also be made of materials other than resin, such as metal. The housing body 20 is a generally rectangular box-shaped structure extending in the width direction. Figure 2 As shown, the housing body 20 has an opening on its upper side. The housing body 20 has a first housing portion 21, a second housing portion 22, and a substrate receiving portion 23. That is, the housing 10 includes a first housing portion 21, a second housing portion 22, and a substrate receiving portion 23.

[0044] The first housing portion 21 is a generally rectangular box-shaped structure extending in the width direction (X-axis direction) and open at the top. The first housing portion 21 has a motor receiving portion 20a that houses the motor 50. That is, the housing 10 has motor receiving portions 20a. Although not shown in the figures, in this embodiment, three motor receiving portions 20a are arranged in the width direction. Each of the three motor receiving portions 20a houses the motor 50 of the three actuator portions 100a. The motor receiving portion 20a is a box-shaped structure open at the top. The motor receiving portion 20a has a first opening 21i open at the top. The first opening 21i is an opening large enough for the motor 50 to pass through in the vertical direction.

[0045] The motor housing 20a has a first bottom wall portion 21a, a first support wall portion 21b, a second support wall portion 21c, and a side wall portion 21d. That is, the housing 10 has a first bottom wall portion 21a, a first support wall portion 21b, a second support wall portion 21c, and a side wall portion 21d. The first bottom wall portion 21a is the lower wall portion among the wall portions constituting the motor housing 20a. The first support wall portion 21b is the wall portion constituting the motor housing 20a located on one axial side (+Y side). The second support wall portion 21c is the wall portion constituting the motor housing 20a located on the other axial side (-Y side). The side wall portions 21d are the wall portions constituting the motor housing 20a located on both sides in the width direction.

[0046] In this embodiment, the first support wall portion 21b is a support wall portion that supports the motor 50 from one axial side (+Y side) between the motor 50 and the reduction mechanism 60. The motor 50 is in contact with the surface of the first support wall portion 21b on the other axial side (-Y side). In this embodiment, the surface of the plate-shaped portion 51b in the motor housing 51 on one axial side is in contact with the surface of the first support wall portion 21b on the other axial side.

[0047] The first support wall portion 21b has a bearing portion 21e that supports the rotatable end of the rotating member 71 on the other axial side (-Y side). Therefore, the rotating member 71 can be supported for rotation using the first support wall portion 21b that supports the motor 50 in the axial direction. Thus, for example, it is not necessary to provide other walls or the like on the axial side (+Y side) of the first support wall portion 21b to support the rotating member 71. Therefore, compared to the case where such other walls or the like are provided, it is easier to miniaturize the electric actuator 100 in the axial direction. Furthermore, at least a portion of the rotating member 71 supported on the bearing portion 21e overlaps with the motor 50 when viewed in the axial direction as described above. Therefore, compared to the case where the entire rotating member 71 is located radially outward from the motor 50, the electric actuator 100 can be miniaturized in the radial direction. Therefore, according to this embodiment, the electric actuator 100 can be miniaturized in both the axial and radial directions while providing the reduction mechanism 60.

[0048] Furthermore, as described above, in this embodiment, the first opening 21i of the motor housing 20a is sized to allow the motor 50 to pass through in the vertical direction. Therefore, the motor 50 can be disposed in the motor housing 20a from above via the first opening 21i. As a result, for example, compared to a structure in which the motor 50 is disposed in the motor housing 20a from one axial side or the other axial side, the electric actuator 100 can be further miniaturized in the axial direction.

[0049] Furthermore, as described above, in this embodiment, the reduction mechanism 60 is composed of two gear portions: a first gear portion 61 and a second gear portion 62. Therefore, the number of components in the reduction mechanism 60 can be reduced, and radial enlargement of the reduction mechanism 60 can be suppressed. Consequently, the number of components in the electric actuator 100 can be reduced, and the electric actuator 100 can be further miniaturized radially.

[0050] In this embodiment, the bearing portion 21e is formed by a hole through which the first support wall portion 21b passes in the axial direction. For example... Figure 5As shown, the bearing portion 21e, when viewed axially, is circular with the second central axis J2 as its center. The supported shaft portion 71b of the rotating member 71 is clearance-fitted with the bearing portion 21e. Thus, the supported shaft portion 71b, supported by the bearing portion 21e, can rotate about the second central axis J2. Figure 2 As shown, in this embodiment, the portion of the supported shaft portion 71b on the other axial side (-Y side) is clearance-fitted with the bearing portion 21e. The end of the supported shaft portion 71b on one axial side (+Y side) is located on the axial side further than the bearing portion 21e. The end of the supported shaft portion 71b on the other axial side is located on the axial side further than the end of the bearing portion 21e on the other axial side. The opening on the other axial side of the bearing portion 21e is blocked by the motor 50. More specifically, the opening on the other axial side of the bearing portion 21e is blocked by the plate-like portion 51b of the motor housing 51. The end of the supported shaft portion 71b located inside the bearing portion 21e is opposed to the motor 50 with a clearance.

[0051] like Figure 3 As shown, an elastic member 54 is disposed inside the motor housing 20a. The elastic member 54 is located on the other side (-Y side) of the axial direction of the motor 50 inside the motor housing 20a. The elastic member 54 clamps the motor 50 between itself and the first support wall 21b in the axial direction and contacts the motor 50 in a state of elastic deformation. Therefore, the motor 50 can be pressed against the first support wall 21b from the other side of the axial direction by the elastic member 54. As a result, axial movement of the motor 50 within the motor housing 20a can be suppressed. Therefore, the motor 50 is subjected to a force by the elastic member 54 toward the axial side (towards the +Y side), thereby suppressing its axial wobble. Since the axial wobble of the motor 50 can be suppressed, the axial wobble of the first gear portion 61 can also be suppressed. Since the first gear section 61 can suppress axial wobble relative to the second gear section 62, uneven wear and noise / vibration / backlash increase on the tooth surfaces of both gears can be suppressed. In addition, axial wobble of the second gear section 62 and the rotating member 71 and the moving member 72 can be suppressed.

[0052] like Figure 9 and Figure 10 As shown, in this embodiment, the elastic member 54 is a metal plate member. The elastic member 54 has a base plate portion 54a, a deformable portion 54b, and a contact portion 54d. The base plate portion 54a is a plate with its surface facing vertically. In this embodiment, the base plate portion 54a is a rectangular plate. Figure 3As shown, the base plate portion 54a contacts the upper surface of the first bottom wall portion 21a. The base plate portion 54a is located below the motor 50. A gap is provided between the base plate portion 54a and the motor 50 in the vertical direction. The end of the base plate portion 54a on the other axial side (-Y side) contacts the surface of the second support wall portion 21c on one axial side (+Y side).

[0053] The deformable portion 54b extends upward from the end of the base plate portion 54a on the other side of the axial direction (-Y side). The deformable portion 54b is located on the other side of the axial direction of the motor 50. The deformable portion 54b is bent in a direction that bulges towards the axial side on a cross-section orthogonal to the width direction (X-axis direction). The deformable portion 54b is a portion that can elastically deform in the axial direction. The surface of the deformable portion 54b on the axial side (+Y side) contacts the motor 50. More specifically, the central portion in the vertical direction of the surface of the deformable portion 54b on the axial side contacts the surface of the cylindrical portion 51a in the motor housing 51 on the other side of the axial direction. The lower end and the upper end of the deformable portion 54b contact the surface of the second support wall portion 21c on the axial side.

[0054] like Figure 10 As shown, a through hole 54c is provided at the center of the deformable portion 54b in the vertical direction, through which the deformable portion 54b passes in the axial direction. The protrusion 51c of the motor housing 51 is located in the through hole 54c. The through hole 54c is an elongated hole that extends in the vertical direction. The deformable portion 54b is bent in a direction that protrudes to one side in the axial direction, so that the upper end of the through hole 54c is open to the upper side. Therefore, when the motor 50 is inserted into the motor housing 20a from the top with the elastic member 54 disposed in the motor housing 20a, the protrusion 51c of the motor 50 can be inserted into the through hole 54c from the upper end of the through hole 54c. Therefore, when the motor 50 is disposed in the motor housing 20a, the contact between the protrusion 51c and the elastic member 54 can be suppressed, and the motor 50 can be easily disposed in the motor housing 20a. Furthermore, by preventing the deformable portion 54b from contacting the protrusion 51c, the deformable portion 54b can be stably contacted with the cylindrical portion 51a of the motor housing 51. Thus, the motor 50 can be stably pressed against the first support wall portion 21b via the deformable portion 54b. Therefore, by applying force to the motor 50 towards the axial side (towards the +Y side) via the deformable portion 54b, as described above, axial wobble of the motor 50, axial wobble of the first gear portion 61, and axial wobble of the second gear portion 62 and the rotating member 71 and the moving member 72 can be suppressed.

[0055] With the motor 50 in contact with the first support wall 21b, the axial gap between the motor 50 and the second support wall 21c is smaller than the axial dimension of the deformable portion 54b in its non-elastically deformed state. Therefore, when the motor 50 is inserted into the motor housing 20a from above with the elastic member 54 disposed within the motor housing 20a, the deformable portion 54b elastically deforms in an axially compressed direction by the motor 50 and the second support wall 21c. Thus, the deformable portion 54b contacts the motor 50 in an elastically deformed state, thereby applying a force to the motor 50 towards the axial side (towards the +Y side).

[0056] The contact portion 54d is connected to the upper end of the deformable portion 54b. The contact portion 54d protrudes upward from the upper end of the deformable portion 54b. In this embodiment, the contact portion 54d is a rectangular plate that is long in the width direction (X-axis direction). The plate surface of the contact portion 54d is orthogonal to the axial direction. Figure 3 As shown, the contact portion 54d is in surface contact with the axial side (+Y side) of the second support wall portion 21c.

[0057] like Figure 9 As shown, the first support wall portion 21b has a through portion 21g that extends through the first support wall portion 21b in the axial direction. In this embodiment, the through portion 21g extends in the vertical direction. The through portion 21g has an opening on the upper side. Figure 3 As shown, the motor shaft 52a passes axially through the through portion 21g. The supported portion 51d of the motor housing 51 is located within the through portion 21g. Figure 5 As shown, the inner surface of the through portion 21g has a bottom portion 21m and a pair of side portions 21n. The bottom portion 21m is the lower part of the inner surface of the through portion 21g. The bottom portion 21m is located below the supported portion 51d. The pair of side portions 21n are portions located on both sides of the inner surface of the through portion 21g in the width direction (X-axis direction). The pair of side portions 21n are located on both sides of the supported portion 51d in the width direction. The bottom portion 21m contacts the lower end of the supported portion 51d. The pair of side portions 21n contact the ends of the supported portion 51d on both sides in the width direction. Thus, the supported portion 51d is supported by the inner surface of the through portion 21g in both the vertical and width directions.

[0058] A pressing member 55 is disposed on the upper side of the supported portion 51d. The pressing member 55 presses the motor 50 from above. The pressing member 55 is fixed to the housing 10. The pressing member 55 clamps the supported portion 51d between it and the bottom portion 21m in the vertical direction. Therefore, the pressing member 55 can suppress the upward movement of the supported portion 51d. Thus, in this embodiment, the supported portion 51d is stably supported in the vertical direction by the pressing member 55 and the bottom portion 21m, and stably supported in the width direction (X-axis direction) by a pair of side portions 21n. As a result, the movement of the motor 50 in the vertical and width directions within the motor housing 20a can be suppressed. Furthermore, by supporting the annular supported portion 51d through which the motor shaft 52a passes, the first central axis J1 of the motor 50 can be configured with high axial precision.

[0059] In this embodiment, the pressing member 55 is made of resin. It should be noted that the pressing member 55 may also be made of materials other than resin, such as metal. Figure 9 As shown, the pressing member 55 has a fixed portion 55a, a first pressing portion 55b, and a pair of second pressing portions 55c. The fixed portion 55a extends in the width direction (X-axis direction). The fixed portion 55a has a pair of fixing holes 55f through which the fixed portion 55a passes in the vertical direction. Figure 5 As shown, a pair of fixing protrusions 25 protrude upward from the upper end of the first support wall portion 21b through a pair of fixing holes 55f in the vertical direction. When viewed vertically, the pair of fixing protrusions 25 are separated by a through portion 21g in the width direction. With the pair of fixing protrusions 25 passing through the pair of fixing holes 55f, the periphery of the fixing hole 55f in the lower surface of the fixed portion 55a contacts the upper surface of the first support wall portion 21b. The upper end of each fixing protrusion 25 is located above the fixing hole 55f. The protruding portion 25a of each fixing protrusion 25 located above the fixing hole 55f is formed, for example, by thermal riveting. Figure 5 The roughly hemispherical shape shown by the double-dotted line contacts the upper surface of the fixed part 55a. Thus, the pressing member 55 is fixed to the upper end of the first support wall part 21b. Therefore, the pressing member 55 is fixed to the housing 10.

[0060] The first pressing part 55b extends downward from the fixed part 55a. The dimension of the first pressing part 55b in the width direction (X-axis direction) is approximately the same as the dimension of the through part 21g in the width direction. The first pressing part 55b is inserted into the through part 21g from the top and fits into the through part 21g. A recess 55e is provided at the lower end of the first pressing part 55b, which is recessed upward. A pair of inclined surfaces 55g located on both sides in the width direction in the inner surface of the recess 55e approach each other in the width direction as they tend to move upward. The pair of inclined surfaces 55g, in a state of contact with the outer peripheral surface of the upper part of the supported part 51d, clamp the outer peripheral surface of the upper part of the supported part 51d in the width direction. The pair of inclined surfaces 55g also contact the outer peripheral surface of the supported part 51d from the top. Therefore, the supported portion 51d can be pressed in the width direction by the first pressing portion 55b, and the supported portion 51d can also be pressed from above by the first pressing portion 55b.

[0061] like Figure 10 As shown, a pair of second pressing portions 55c protrude downwards from the fixed portion 55a. In this embodiment, the pair of second pressing portions 55c protrude downwards from the ends on both sides of the fixed portion 55a in the width direction. Figure 8 As shown, one second pressing part 55c is located on the side (+X side) of the width direction relative to the first central axis J1. The other second pressing part 55c is located on the other side (-X side) of the width direction relative to the first central axis J1. The lower surfaces of the pair of second pressing parts 55c are arc-shaped along the outer peripheral surface of the cylindrical part 51a of the motor housing 51 when viewed axially. The lower surfaces of the pair of second pressing parts 55c contact the outer peripheral surface of the cylindrical part 51a from above. Thus, the cylindrical part 51a is pressed from above by the pair of second pressing parts 55c. The lower surfaces of the pair of second pressing parts 55c are located on the lower side as they move away from the other second pressing part 55c in the width direction (X-axis direction). Therefore, the upper part of the cylindrical part 51a is sandwiched in the middle by the lower surfaces of the pair of second pressing parts 55c in the width direction. Thus, the cylindrical part 51a can be pressed in the width direction by the pair of second pressing parts 55c.

[0062] like Figure 8As shown, the first housing portion 21 has a pair of protruding wall portions 21h that protrude upward from the first bottom wall portion 21a of the motor receiving portion 20a. The pair of protruding wall portions 21h are arranged spaced apart in the width direction (X-axis direction). One protruding wall portion 21h is connected to one side wall portion 21d. The other protruding wall portion 21h is connected to the other side wall portion 21d. The pair of protruding wall portions 21h are located below the cylindrical portion 51a. The upper edges of the pair of protruding wall portions 21h are located downward as they move away from each of the pair of side wall portions 21d in the width direction. This prevents the upper edges of the pair of protruding wall portions 21h from contacting the cylindrical portion 51a. Figure 2 As shown, a pair of protruding wall portions 21h protrude upwards from one axial side (+Y side) of the first bottom wall portion 21a. The pair of protruding wall portions 21h are located on the other axial side (-Y side) of the first support wall portion 21b. The pair of protruding wall portions 21h and the first support wall portion 21b are positioned opposite each other with a gap. A plate-shaped portion 51b is inserted into the axial gap between the pair of protruding wall portions 21h and the first support wall portion 21b. Thus, the plate-shaped portion 51b is positioned axially. The plate-shaped portion 51b, for example, has a clearance fit between the pair of protruding wall portions 21h and the first support wall portion 21b axially.

[0063] The second housing portion 22 is located on one axial side (+Y side) of the first housing portion 21. The second housing portion 22 extends in the width direction (X-axis direction). The second housing portion 22 is box-shaped with an opening on one axial side. The second housing portion 22 has a reduction mechanism receiving portion 20b that houses the reduction mechanism 60 inside. Although not shown in the figure, in this embodiment, three reduction mechanism receiving portions 20b are provided in a manner arranged in the width direction. Each of the three reduction mechanism receiving portions 20b houses the reduction mechanism 60 of the three actuator portions 100a. Each reduction mechanism receiving portion 20b is arranged on one axial side of each motor receiving portion 20a.

[0064] The reduction gear receiving portion 20b has an opening on one axial side (+Y side). This opening on the axial side of the reduction gear receiving portion 20b is sealed by a second cover 40. The wall portion on the other axial side (-Y side) of the wall portion constituting the reduction gear receiving portion 20b is the first support wall portion 21b, which constitutes the wall portion on the axial side of the motor receiving portion 20a. (As follows...) Figure 6 As shown, the speed reduction mechanism receiving part 20b has a first gear receiving part 21j and a second gear receiving part 21k.

[0065] The first gear receiving portion 21j houses the first gear portion 61. The portion of the motor shaft 52a in which the first gear portion 61 is fixed is located inside the first gear receiving portion 21j. The first gear receiving portion 21j extends in the vertical direction. The first gear receiving portion 21j has an opening on its upper side. The first gear receiving portion 21j is located on the axial side (+Y side) of the through portion 21g. The interior of the first gear receiving portion 21j is connected to the interior of the through portion 21g.

[0066] The second gear receiving portion 21k houses the second gear portion 62. The second gear receiving portion 21k is located on one side (+X side) of the width direction of the first gear receiving portion 21j. The interior of the second gear receiving portion 21k is connected to the interior of the first gear receiving portion 21j. When viewed axially, the second gear receiving portion 21k is approximately circular with the second central axis J2 as its center.

[0067] like Figure 2 As shown, the substrate receiving portion 23 houses the substrate 56 internally. The substrate 56 is electrically connected to the motor 50. The surface of the substrate 56 faces the vertical direction. Figure 8 As shown, the substrate 56 has a portion located on the upper side of each motor 50. Multiple conductive portions 53a, extending upwards from each of the three actuator sections 100a, are electrically connected to the substrate 56. These conductive portions 53a are electrically connected to the coils of the stator 53. The conductive portions 53a can be formed by wires constituting the coils of the stator 53, or by busbars connected to those wires. Although not shown in the figure, the substrate 56 has an inverter circuit that supplies power to the coils of the stator 53. Power is supplied from this inverter circuit to the coils of the stator 53 via the multiple conductive portions 53a, thereby driving the motor 50.

[0068] like Figure 1 As shown, the substrate receiving portion 23 is a generally rectangular box-shaped structure extending in the width direction (X-axis direction) and open on the upper side. Figure 2 As shown, the substrate receiving portion 23 is located above the first housing portion 21 and the second housing portion 22. The opening on the upper side of the substrate receiving portion 23 is sealed by the first cover 30. The substrate receiving portion 23 has a second bottom wall portion 23a and a peripheral wall portion 23b. The second bottom wall portion 23a is the lower wall portion among the wall portions constituting the substrate receiving portion 23. In this embodiment, the second bottom wall portion 23a constitutes the upper wall portion among the wall portions constituting the deceleration mechanism receiving portion 20b. The peripheral wall portion 23b protrudes upward from the outer periphery of the second bottom wall portion 23a. The peripheral wall portion 23b is generally rectangular. The opening on the upper side of the peripheral wall portion 23b is the opening on the upper side of the substrate receiving portion 23.

[0069] The axial dimension of the substrate receiving portion 23 is larger than the sum of the axial dimensions of the motor receiving portion 20a and the axial dimensions of the reduction mechanism receiving portion 20b. The substrate receiving portion 23 has a portion located above each motor receiving portion 20a and a portion located axially closer (+Y side) than each motor receiving portion 20a. As described above, in this embodiment, the moving member 72 protrudes axially from the inside of the housing 10 to the outside of the housing 10. That is, the substrate receiving portion 23 has a portion located axially closer to the side where the moving member 72 protrudes from the motor receiving portion 20a. Therefore, the substrate receiving portion 23 can be made larger axially while suppressing the overall axial dimension enlargement of the electric actuator 100. As a result, the substrate 56 housed in the substrate receiving portion 23 can be made larger axially when the plate surface is facing up and down. Therefore, compared with the case where the substrate 56 is arranged with the plate surface facing the axial direction, the radial enlargement of the electric actuator 100 can be suppressed, and the overall axial enlargement of the electric actuator 100 can also be suppressed.

[0070] The interior of the portion of the substrate receiving portion 23 located above each motor receiving portion 20a is connected to the interior of each motor receiving portion 20a via a first opening 21i. The portion of the substrate receiving portion 23 located on the axial side (+Y side) of each motor receiving portion 20a includes a portion located above the reduction mechanism receiving portion 20b and a portion located on the axial side of the reduction mechanism receiving portion 20b. The interior of the substrate receiving portion 23 is separated from the interior of the reduction mechanism receiving portion 20b by a second bottom wall portion 23a.

[0071] The substrate receiving portion 23 has a substrate support portion 23c that supports the substrate 56. The substrate support portion 23c protrudes upward from the second bottom wall portion 23a. The substrate support portion 23c has a base portion 23d and a thermally riveted portion 23e. That is, the housing 10 has a base portion 23d and a thermally riveted portion 23e. The base portion 23d protrudes upward from the second bottom wall portion 23a. The base portion 23d is, for example, cylindrical. The base portion 23d contacts the lower surface of the substrate 56. The base portion 23d supports the substrate 56 from below.

[0072] The thermally riveted portion 23e is connected to the upper side of the base portion 23d. The thermally riveted portion 23e is the portion that secures the substrate 56 by thermal riveting. Figure 2 In the diagram, the heat-riveting portion 23e before heat riveting is represented by a solid line, and the heat-riveting portion 23e after heat riveting is represented by a double-dotted line. The heat-riveting portion 23e before heat riveting is cylindrical with an outer diameter smaller than the outer diameter of the base portion 23d. In its state before heat riveting, the heat-riveting portion 23e passes axially through a hole provided in the substrate 56. The portion of the heat-riveting portion 23e in its state before heat riveting that protrudes upwards from the substrate 56 is heat-riveted as follows. Figure 2The portion shown by the double-dotted line is approximately hemispherical, and the portion that has been heat-riveted contacts the upper surface of the substrate 56. Thus, the substrate 56 is fixed by the heat-riveting portion 23e. In this way, by using a structure to fix the substrate 56 using heat riveting, the portion fixing the substrate 56 is less likely to protrude upwards compared to fixing the substrate 56 with bolts. Therefore, it is possible to further suppress the enlargement of the electric actuator 100 in the vertical direction. In this embodiment, multiple substrate support portions 23c are provided.

[0073] The first cover 30 is fixed to the upper end of the substrate receiving portion 23. The first cover 30 seals the upper opening of the substrate receiving portion 23. The first cover 30 has a top plate portion 31 and a frame-shaped portion 32. The top plate portion 31 is plate-shaped with its surface facing up and down. The frame-shaped portion 32 protrudes downward from the outer peripheral edge of the lower surface of the top plate portion 31. The frame-shaped portion 32 is generally square-shaped. The frame-shaped portion 32 fits into the upper opening of the peripheral wall portion 23b in the substrate receiving portion 23. The outer peripheral surface of the frame-shaped portion 32 and the inner peripheral surface of the peripheral wall portion 23b are sealed by a second sealing member 84. The second sealing member 84 is, for example, an O-ring.

[0074] The second cover 40 is located on one axial side (+Y side) of the second housing portion 22. The second cover 40 seals the openings on one axial side of each reduction gear receiving portion 20b. Figure 1 As shown, the second cover 40 has a first cylindrical portion 41, a cover portion 42, and a mounting portion 45. That is, the housing 10 has a first cylindrical portion 41, a cover portion 42, and a mounting portion 45. The mounting portion 45 is used to assemble the electric actuator 100 to the device on which the electric actuator 100 is mounted. The mounting portions 45 are respectively provided on both sides of the second cover 40 in the width direction.

[0075] The first cylindrical portion 41 is a cylindrical portion extending axially. The first cylindrical portion 41 is open on both sides axially. In this embodiment, the first cylindrical portion 41 is generally cylindrical about the second central axis J2. The first cylindrical portion 41 is provided for each actuator portion 100a. In this embodiment, three first cylindrical portions 41 are provided at intervals in the width direction (X-axis direction).

[0076] like Figure 2As shown, the first cylindrical portion 41 is located on one axial side (+Y side) of the reduction mechanism 60. More specifically, the first cylindrical portion 41 is located on one axial side of the second gear portion 62. The end of the first cylindrical portion 41 on the other axial side (-Y side) is located inside the reduction mechanism receiving portion 20b. At least a portion of the rotating member 71 is located inside the first cylindrical portion 41. In this embodiment, the portion of the rotating member 71 located on the axial side closer to the part fixed to the second gear portion 62 is substantially entirely located inside the first cylindrical portion 41. A portion of the moving member 72 is located inside the first cylindrical portion 41. The moving member 72 protrudes axially from an opening on one axial side of the first cylindrical portion 41. With the moving member 72 located on the most axial side, the connected portion 72b is located outside the first cylindrical portion 41, and the second cylindrical portion 72a is substantially entirely located inside the first cylindrical portion 41. The first cylindrical portion 41 has a threaded receiving portion 41a and a sealing receiving portion 41b.

[0077] The threaded receiving portion 41a is a portion that houses at least a portion of the first threaded portion 71c and at least a portion of the second threaded portion 72c. In this embodiment, the threaded receiving portion 41a houses the entire first threaded portion 71c. It should be noted that a portion of the first threaded portion 71c may also be located outside the threaded receiving portion 41a. When the moving member 72 is positioned at its axially furthest opposite side (-Y side), the threaded receiving portion 41a houses the entire second threaded portion 72c. When the moving member 72 is positioned at its axially furthest side (+Y side), the threaded receiving portion 41a houses the portion of the second threaded portion 72c on the axially opposite side. It should be noted that, regardless of the axial position of the moving member 72, the entire second threaded portion 72c may be housed inside the threaded receiving portion 41a, or a portion of the second threaded portion 72c may be located outside the threaded receiving portion 41a, regardless of the axial position of the moving member 72.

[0078] The threaded receiving portion 41a is a cylindrical shape extending axially. In this embodiment, the threaded receiving portion 41a is generally cylindrical about a second central axis J2. The threaded receiving portion 41a has a second opening 41c that opens on one axial side (+Y side). The second opening 41c is the end of the threaded receiving portion 41a on one axial side. The end of the threaded receiving portion 41a on one axial side is the end of the first cylindrical portion 41 on one axial side. The moving member 72 passes through the second opening 41c axially. The moving member 72 protrudes from the inside of the threaded receiving portion 41a to the outside of the threaded receiving portion 41a via the second opening 41c. The moving member 72 has a clearance fit with the inside of the threaded receiving portion 41a. In this embodiment, the second opening 41c opens into an external space S1a located outside the electric actuator 100. The external space S1a is filled with fluid flowing in a flow path switched by the electric actuator 100. Therefore, fluid flows from the second opening 41c into the interior of the first cylindrical portion 41. The fluid is, for example, water. It should be noted that the fluid may also be a fluid other than water, such as oil. The portion of the moving member 72 located on the axial side relative to the first cylindrical portion 41 is exposed in the external space S1a.

[0079] like Figure 7 As shown, the inner surface of the threaded receiving portion 41a has a support surface 44. In this embodiment, the support surface 44 is a surface that supports the movable member 72 so that it can move axially. The support surface 44 has a curved support portion 44a and a pair of flat support portions 44b. The curved support portion 44a is an arc-shaped surface centered on the second central axis J2 when viewed axially. The curved support portion 44a is positioned opposite or in contact with the arc-shaped surface centered on the second central axis J2 on the outer peripheral surface of the movable member 72 with a small gap, supporting the arc-shaped surface. It should be noted that the shape of the support surface 44 is not particularly limited as long as it can support the movable member 72. For example, the support surface 44 may also be shaped to protrude inward from the first cylindrical portion 41 within a range that does not significantly impede the axial movement of the movable member 72. In this case, it is sufficient to appropriately design the shape of the outer peripheral surface of the movable member 72.

[0080] A pair of planar support portions 44b are arranged such that they are spaced apart by the second central axis J2 in the width direction (X-axis direction). Each pair of planar support portions 44b supports a pair of planar portions 72d on the outer peripheral surface of the moving member 72. The pair of planar portions 72d and the pair of planar support portions 44b are positioned opposite or in contact with each other with a small gap. Therefore, even if the moving member 72 wants to rotate when the rotating member 71 rotates, the rotation of the moving member 72 is prevented by the abutment between the planar portions 72d and the planar support portions 44b. Thus, when the second threaded portion 72c provided on the moving member 72 feeds axially, the moving member 72 moves axially without rotation. A pair of planar support portions 44b are provided on one axial side (+Y side) of the inner surface of the threaded receiving portion 41a. The ends on the other axial side (-Y side) of the pair of planar support portions 44b are arranged such that they are further away from the other axial side of the threaded receiving portion 41a. In this embodiment, the pair of planar support portions 44b are respectively cut off in the vertical direction by the groove 43 described later. The portion of the inner surface of the thread receiving portion 41a that is provided with a pair of flat support portions 44b and the portion provided with groove 43 is a curved support portion 44a.

[0081] A groove 43 extending axially is provided on the inner surface of the threaded receiving portion 41a. The groove 43 is recessed inwardly from the support surface 44 in the radial direction centered on the second central axis J2. For example... Figure 2 As shown, groove 43 extends from one axial side (+Y side) end of threaded receiving portion 41a to the other axial side (-Y side) end of threaded receiving portion 41a. Groove 43 opens on both axial sides. The other axial end of groove 43 opens into the interior of sealing receiving portion 41b.

[0082] like Figure 7 As shown, in this embodiment, multiple slots 43 are provided at intervals around the second central axis J2. The multiple slots 43 are equally spaced around the second central axis J2 in a manner that covers the entire circumference. In this embodiment, four slots 43 are provided. The four slots 43 include a pair of slots 43 spaced apart from the second central axis J2 in the vertical direction and a pair of slots 43 spaced apart from the second central axis J2 in the width direction (X-axis direction). A portion of the pair of slots 43 spaced apart from the second central axis J2 in the width direction is respectively provided on a pair of planar support portions 44b, and the pair of planar support portions 44b are respectively cut off in the vertical direction.

[0083] like Figure 2As shown, the seal receiving portion 41b is located on the other axial side (-Y side) of the threaded receiving portion 41a. The end of the seal receiving portion 41b on one axial side (+Y side) is connected to the end of the threaded receiving portion 41a on the other axial side. The seal receiving portion 41b is annular with the second central axis J2 as its center. The end of the seal receiving portion 41b on the other axial side is the end of the first cylindrical portion 41 on the other axial side. The inner diameter of the seal receiving portion 41b is larger than the inner diameter of the threaded receiving portion 41a. The rotating member 71 passes axially through the interior of the seal receiving portion 41b.

[0084] The sealing member receiving portion 41b houses the first sealing member 80 internally. That is, the first sealing member 80 is disposed inside the first cylindrical portion 41. The first sealing member 80 seals the inner surface of the first cylindrical portion 41 with the rotating member 71. In this embodiment, the first sealing member 80 seals the inner circumferential surface of the sealing member receiving portion 41b with the outer circumferential surface of the shaft body portion 71a in the rotating member 71. The first sealing member 80 is annular about the second central axis J2. The first sealing member 80 is, for example, a sealing member having a lip that presses against the outer circumferential surface of the rotating member 71. The first sealing member 80 is located on the opposite side (-Y side) axially than the moving member 72. Even if fluid enters the interior of the first cylindrical portion 41 from the second opening portion 41c, the first sealing member 80 can prevent the fluid from reaching the reduction mechanism 60 and the motor 50.

[0085] A plate member 83 is disposed on the opposite axial side (-Y side) of the first sealing member 80. The plate member 83 supports the first sealing member 80 from the opposite axial side. Therefore, it can prevent the first sealing member 80 from falling out of the first cylindrical portion 41. The plate surface of the plate member 83 faces axially. Figure 11 As shown, the plate member 83 is a rounded quadrilateral when viewed axially. The plate member 83 has a through hole 83a that extends through it axially. Figure 2 As shown, the shaft body 71a of the rotating member 71 passes through the through hole 83a axially. The outer periphery of the axial side (+Y side) of the plate member 83 contacts the end face of the other axial side of the first cylindrical part 41. Figure 11 As shown, the plate member 83 is supported in the vertical direction and the width direction (X-axis direction) by the frame portion 42b of the cover portion 42 (described later) and the protrusion 41d that protrudes from the end face of the first cylindrical portion 41 on the other side of the axial direction.

[0086] like Figure 2As shown, plate member 83 is located on one axial side (+Y side) of the reduction mechanism 60. More specifically, plate member 83 is located on one axial side of the second gear portion 62. Plate member 83 clamps the second gear portion 62 between itself and the first support wall portion 21b in the axial direction. That is, at least a portion of the reduction mechanism 60 is located between plate member 83 and the first support wall portion 21b in the axial direction. In this embodiment, the second gear portion 62, which is part of the reduction mechanism 60, is located between plate member 83 and the first support wall portion 21b in the axial direction.

[0087] A first spacer 81 surrounding the rotating member 71 is disposed between the plate member 83 and the reduction mechanism 60 in the axial direction. A second spacer 82 surrounding the rotating member 71 is disposed between the reduction mechanism 60 and the first support wall portion 21b in the axial direction. Therefore, the gaps between the plate member 83 supporting the first sealing member 80 and the reduction mechanism 60, as well as the gap between the reduction mechanism 60 and the first support wall portion 21b, can be filled by the first spacer 81 and the second spacer 82, respectively. As a result, the axial movement of the plate member 83 can be suppressed without the need for bolts or the like to fix the plate member 83. Therefore, the number of components and assembly steps of the electric actuator 100 can be reduced by eliminating the need for bolts or the like to fix the plate member 83. Furthermore, by adjusting the axial dimensions of the first spacer 81 and the second spacer 82, axial wobbling of the plate member 83 can be appropriately suppressed.

[0088] The first spacer 81 is located axially between the plate member 83 and the second gear portion 62. The first spacer 81 contacts at least one of the plate member 83 and the second gear portion 62. The second spacer 82 is located axially between the second gear portion 62 and the first support wall portion 21b. The second spacer 82 contacts at least one of the second gear portion 62 and the first support wall portion 21b. Figure 11 As shown, the first spacer 81 and the second spacer 82 are annular rings surrounding the second central axis J2. The first spacer 81 and the second spacer 82 are plates with their surfaces facing axially. The first spacer 81 and the second spacer 82 are, for example, washers. The axial dimensions of the first spacer 81 and the second spacer 82 may be the same as or different from each other. Operators assembling the electric actuator 100 may appropriately select the spacers used as the first spacer 81 and the second spacer 82 based on the tolerances of the assembled components.

[0089] The cover portion 42 connects a plurality of first cylindrical portions 41 to each other. The cover portion 42 has a cover body portion 42a and a frame portion 42b. The cover body portion 42a extends in the width direction (X-axis direction). In this embodiment, the cover body portion 42a is plate-shaped with its plate surface facing axially. The cover body portion 42a connects a plurality of first cylindrical portions 41 to each other. More specifically, the cover body portion 42a connects the threaded receiving portion 41a and the sealing receiving portion 41b in each of the first cylindrical portions 41 to each other. Figure 3 As shown, the cover body 42a seals the opening on one axial side (+Y side) of the second housing part 22. The frame part 42b protrudes from the outer peripheral edge of the cover body 42a to the other axial side (-Y side). The frame part 42b is a generally rectangular frame that is long in the width direction (X-axis direction). The frame part 42b fits into the inner side of the second housing part 22. The outer peripheral surface of the frame part 42b and the inner peripheral surface of the second housing part 22 are sealed by a third sealing member 85. The third sealing member 85 is, for example, an O-ring.

[0090] like Figure 2 As shown, the electric actuator 100 includes at least a portion of a path portion 90 provided in the housing 10. The path portion 90 has a portion formed by a groove 43. The path portion 90 connects the space S1b located on the other axial side (-Y side) of the moving member 72 when it moves axially, and the external space S1a located on the axial side (+Y side) of the threaded receiving portion 41a. Therefore, when the moving member 72 moves axially while fluid is inside the first cylindrical portion 41, fluid can flow between the space S1b and the external space S1a via the path portion 90. The path portion 90 has a portion formed by the groove 43, so fluid can easily flow into the path portion 90. Thus, even if the volume of the space S1b changes due to the axial movement of the moving member 72, fluid can easily flow into or out of the space S1b via the path portion 90. Therefore, the pressure difference between the fluids in space S1b and external space S1a can be appropriately suppressed, and the increase in the force required to move the moving member 72 axially can be appropriately suppressed. Therefore, the torque of the motor 50 required to move the moving member 72 axially is reduced. Thus, the motor 50 can be miniaturized. Therefore, the electric actuator 100 can be miniaturized.

[0091] In this embodiment, as described above, a reduction mechanism 60 is provided connected to the rotor 52, and the rotation of the rotor 52 is transmitted to the rotating member 71 via the reduction mechanism 60. Therefore, the torque of the motor 50 is increased by the reduction mechanism 60 and transmitted to the rotating member 71. Consequently, the torque of the motor 50 required to rotate the rotating member 71 and move the moving member 72 axially is further reduced. Therefore, the motor 50 can be further miniaturized, and the electric actuator 100 can be further miniaturized.

[0092] In this embodiment, space S1b is the space located axially between the moving member 72 and the first sealing member 80. Space S1b also includes the space within the internal space of the sealing member receiving portion 41b located on one axial side (+Y side) of the first sealing member 80. When the moving member 72 moves to one axial side, the volume of space S1b increases. When the moving member 72 moves to the other axial side (-Y side), the volume of space S1b decreases.

[0093] In this embodiment, as described above, at least a portion of the rotating member 71 is located inside the second cylindrical portion 72a of the moving member 72. The second cylindrical portion 72a opens on the other axial side (-Y side). Therefore, the internal space of the second cylindrical portion 72a is connected to the space S1b located on the other axial side of the moving member 72. Thus, the internal space of the second cylindrical portion 72a is connected to the external space S1a via the space S1b and the path portion 90. Therefore, when the moving member 72 moves axially, fluid can easily flow between the internal space of the second cylindrical portion 72a and the external space S1a. Therefore, the torque of the motor 50 required for the moving member 72 to move axially can be further reduced. Thus, the motor 50 can be further miniaturized, and the electric actuator 100 can be further miniaturized. Furthermore, the moving member 72 is provided with a structure having a second cylindrical portion 72a with a second threaded portion 72c on its inner circumferential surface, thereby simplifying the structure of the electric actuator 100 compared to the case where a cylindrical portion for the moving member 72 is provided on the rotating member 71 for insertion.

[0094] In this embodiment, the path portion 90 has an extending path portion 91 extending axially. The extending path portion 91 is formed by a groove 43. Therefore, it is easy to connect the external space S1a and the space S1b through the extending path portion 91 extending axially. In this embodiment, the extending path portion 91 is formed by a groove 43 provided on the inner surface of the first cylindrical portion 41 and opening on one axial side (+Y side). The inner surface of the extending path portion 91 is the inner surface of the groove 43. Figure 12 As shown, the inner surface of the extension path portion 91 is connected to the support surface 44. Therefore, the fluid flowing in the extension path portion 91 enters the gap between the support surface 44 and the moving member 72, making it easy for the moving member 72 to move axially.

[0095] like Figure 2As shown, the extension path portion 91 opens on both axial sides. The end of the extension path portion 91 on one axial side (+Y side) opens into and connects to the external space S1a. The portion of the extension path portion 91 located on the other axial side (-Y side) of the moving member 72 opens into and connects to space S1b. In this embodiment, when the moving member 72 is located at its furthest point on the other axial side, the end of the extension path portion 91 on the other axial side is connected to space S1b.

[0096] like Figure 12 As shown, in this embodiment, four slots 43 are provided, and therefore four extension path portions 91 are also provided. The four extension path portions 91 are arranged at equal intervals around the second central axis J2 in a manner that covers the entire circumference. The four extension path portions 91 include a pair of extension path portions 91 that are separated from the second central axis J2 in the vertical direction and a pair of extension path portions 91 that are separated from the second central axis J2 in the width direction (X-axis direction).

[0097] In this embodiment, the path portion 90 has a gap path portion 92. The gap path portion 92 is formed by the gap between the planar portion 72d of the moving member 72 and the curved support portion 44a in the inner surface of the first cylindrical portion 41. The gap path portion 92 is provided between the portion of the curved support portion 44a located on the opposite side (-Y side) axially than the planar support portion 44b and the planar portion 72d. A pair of gap path portions 92 are provided, separated by the second central axis J2 in the width direction (X-axis direction). The pair of gap path portions 92 are located radially inside the pair of extended path portions 91 arranged in the width direction separated by the second central axis J2, respectively, and are connected to the pair of extended path portions 91. In this embodiment, instead of providing the planar support portion 44b as an integral part of the inner surface of the first cylindrical portion 41 in the axial direction, the planar support portion 44b is arranged such that its end on the other side of the axial direction of the first cylindrical portion 41 is further away from the axial direction (+Y side), thereby enabling the clearance path portion 92 to be provided. This allows fluid to flow more easily to the path portion 90. Furthermore, the area of ​​the portion of the outer peripheral surface of the moving member 72 that rubs against the inner surface of the first cylindrical portion 41 can be reduced, thus making it easier for the moving member 72 to move axially.

[0098] Hereinafter, embodiments different from the embodiments described above will be described. In the following descriptions of each embodiment, descriptions may be omitted by appropriately labeling the same reference numerals as those used for configurations identical to those described in the preceding paragraphs of each embodiment. Furthermore, sometimes the same names are used for parts corresponding to the configurations described in the preceding paragraphs of each embodiment, but different reference numerals are used. Points that differ from the above configurations are described, while points that are identical to the above configurations are omitted. It should be noted that, as for the configurations omitted in the following embodiments, configurations identical to those described in the preceding paragraphs of each embodiment may be used to the extent that they do not contradict each other.

[0099] <Second Implementation Method>

[0100] like Figure 13 As shown, the configuration of the second cover 240 of the housing 210 of the electric actuator 200 differs from that of the first embodiment. In the first cylindrical portion 241 of the second cover 240, the threaded receiving portion 241a has a small-diameter portion 241e and a large-diameter portion 241f. The small-diameter portion 241e is the portion having a support surface 44. The large-diameter portion 241f is located on the other axial side (-Y side) of the small-diameter portion 241e. The end of the large-diameter portion 241f on one axial side (+Y side) is connected to the end of the small-diameter portion 241e on the other axial side. The inner diameter of the large-diameter portion 241f is larger than the inner diameter of the small-diameter portion 241e. Therefore, the inner circumferential surface of the large-diameter portion 241f is disposed separately from the outer circumferential surface of the moving member 72 and does not contact the outer circumferential surface of the moving member 72. Therefore, a gap path portion 293 with a flow path cross-sectional area larger than that of the extension path portion 291 can be provided between the inner peripheral surface of the large-diameter portion 241f and the outer peripheral surface of the moving member 72. This allows fluid to flow more easily into the path portion 290. Furthermore, by providing the large-diameter portion 241f, the axial dimension of the small-diameter portion 241e provided on the support surface 44 can be reduced. This reduces the area of ​​the portion of the outer peripheral surface of the moving member 72 that rubs against the inner surface of the first cylindrical portion 241 when the moving member 72 moves axially. Therefore, the moving member 72 can move more easily in the axial direction.

[0101] In this embodiment, the extension path portion 291 is formed by a groove 243 extending axially from one end of the small diameter portion 241e to the other end. The other end of the extension path portion 291, i.e., the other end of the groove 243, is connected to the interior of the large diameter portion 241f. The extension path portion 291 is connected to the space S1b via the gap path portion 293. The other configurations of the electric actuator 200 are the same as those of the electric actuator 100 in the first embodiment.

[0102] <Third Implementation Method>

[0103] like Figure 14As shown, the actuator portion 300a of the electric actuator 300 in this embodiment differs from the electric actuator 100 of the first embodiment. In the actuator portion 300a, the rotating member 371 has a third cylindrical portion 371a, a shaft portion 371d, and a supported shaft portion 71b. The third cylindrical portion 371a is a cylindrical shape extending axially. More specifically, the third cylindrical portion 371a is a generally cylindrical shape centered on the second central axis J2. The third cylindrical portion 371a is open on one axial side (+Y side). The end of the third cylindrical portion 371a on the other axial side is closed. The third cylindrical portion 371a has a first threaded portion 371c on its inner circumferential surface. The third cylindrical portion 371a is located inside the first cylindrical portion 341 in the second cover 240. The outer circumferential surface of the third cylindrical portion 371a is supported by a support surface 344 provided on the inner surface of the first cylindrical portion 341 so that it can rotate about the second central axis J2. That is, in this embodiment, the support surface 344 supports the rotating member 371. In this embodiment, the support surface 344 is different from the support surface 44 in the first embodiment, and does not have a planar support portion 44b. The other configurations of the first cylindrical portion 341 are the same as those of the first cylindrical portion 41 in the first embodiment.

[0104] The third cylindrical portion 371a has a hole 371e that extends from the inner circumferential surface to the outer circumferential surface. In this embodiment, the hole 371e is provided at the end of the peripheral wall portion of the third cylindrical portion 371a on the other axial side (-Y side). Multiple holes 371e are provided at intervals around the second central axis J2 in the circumferential direction. The shaft portion 371d extends from the end of the third cylindrical portion 371a on the other axial side in the opposite direction. The shaft portion 371d passes axially through the seal receiving portion 41b. The second gear portion 62 is fixed to the shaft portion 371d. The supported shaft portion 71b is connected to the end of the shaft portion 371d on the other axial side.

[0105] The moving member 372 of the actuator section 300a is a shaft extending axially. The moving member 372 has a main shaft portion 372a and a connected portion 72b. The main shaft portion 372a extends axially. A second threaded portion 372c is provided on the outer peripheral surface of the main shaft portion 372a. That is, the moving member 372 has a second threaded portion 372c on its outer peripheral surface. At least a portion of the main shaft portion 372a is located inside the third cylindrical portion 371a. That is, at least a portion of the moving member 372 is located inside the third cylindrical portion 371a. The outer diameter of the main shaft portion 372a is smaller than the outer diameter of the connected portion 72b. The moving member 372 is suppressed from rotating about a second central axis J2, for example, by having a drive object (not shown) connected to the connected portion 72b.

[0106] Furthermore, a portion of the support surface 344 near the second opening (opening) 41c is provided with a protrusion 372h that protrudes radially inward toward the second central axis J2. An axially extending planar portion 372g is provided at the outer diameter of the moving member 372 having the second threaded portion 372c, i.e., at the outer diameter of the main shaft portion 372a. The top end of the protrusion 372h contacts the planar portion 372g, thereby suppressing rotation of the moving member 372 around the second central axis J2. The planar portion 372g can be the bottom surface of a groove extending axially, or it can be a planar portion 72d provided on the outer peripheral surface of the moving member 72 in the first embodiment.

[0107] In this embodiment, the path portion 390 has both a portion formed by a groove and a portion formed by a hole. The path portion 390 has an extending path portion 91 and a hole path portion 392. The hole path portion 392 is formed by a hole 371e that extends from the inner peripheral surface to the outer peripheral surface of the third cylindrical portion 371a. Therefore, the space S2b inside the third cylindrical portion 371a and the external space S1a can be connected through the path portion 390. As a result, when the moving member 372, which is located in at least a portion of the third cylindrical portion 371a, moves axially, fluid can easily flow appropriately between the space S2b located on the other axial side (-Y side) of the moving member 372 and the external space S1a via the path portion 390. Therefore, the torque of the motor 50 required for the moving member 372 to move axially can be reduced, and the electric actuator 300 can be miniaturized. The space S2b is the space located on the other axial side of the moving member 372 in the internal space of the third cylindrical portion 371a. The hole path section 392 connects the space S2b and the extension path section 91.

[0108] The other configurations of the actuator section 300a are the same as those of the actuator section 100a in the first embodiment. The other configurations of the electric actuator 300 are the same as those of the electric actuator 100 in the first embodiment.

[0109] <Fourth Implementation Method>

[0110] like Figure 15 As shown, in the electric actuator 400 of this embodiment, the rotating member 471 is the motor shaft of the motor 450. Therefore, compared with the case where a reduction gear is provided, the number of components in the electric actuator 400 can be reduced. Furthermore, by providing the path portion 90, as described above, the torque of the motor 450 required to move the moving member 72 axially can be reduced, so the motor 450 can be made smaller even without a reduction gear. The other configurations of the electric actuator 400 are the same as those of the electric actuator 100 of the first embodiment.

[0111] This invention is not limited to the embodiments described above, and other configurations and methods can be employed within the scope of the technical concept of this invention. The path portion may have at least one of a portion formed by a groove and a portion formed by a hole, or it may have any portion. Alternatively, the path portion may not have a portion formed by a groove but have a portion formed by a hole. When the path portion has an extended path portion extending in a predetermined direction (axial direction), the extended path portion may also be formed by a hole. In this case, the extended path portion may, for example, be formed by a hole provided in the wall portion constituting the first cylindrical portion extending in the predetermined direction. The predetermined direction in which the moving member moves can be any direction, or it may be a direction different from the axial direction of the motor.

[0112] The bearing portion supporting the rotating component can be simply located within the support wall and can be of any configuration. The bearing portion can also be constructed by embedding a bearing, such as a rolling bearing, into the support wall. The support wall may also not have a bearing portion supporting the rotating component. Alternatively, the rotating component may overlap with the motor when viewed axially. Or, the rotating component may not overlap with the motor when viewed axially.

[0113] The reduction gear mechanism only needs to reduce the rotational speed of the rotor and transmit it to the rotating components; it can be of any configuration. The reduction gear mechanism can also consist of three or more gear sections. It can also be a structure that transmits rotation via pulleys and belts. The motor can be any type of motor. The motor can also be an external rotor type motor.

[0114] The application of the electric actuator of the present invention is not particularly limited. The electric actuator can also be mounted on any device.

[0115] It should be noted that this technology can have the following configuration.

[0116] (1) An electric actuator comprising: a motor; a rotating member driven by the motor to rotate, the rotating member having a first threaded portion; a moving member having a second threaded portion engaging with the first threaded portion, the moving member moving in a predetermined direction as the rotating member rotates; a housing having a first cylindrical portion extending in the predetermined direction; and a path portion having at least a portion of the path portion disposed in the housing, the first cylindrical portion having a threaded receiving portion accommodating at least a portion of the first threaded portion and at least a portion of the second threaded portion, the threaded receiving portion having an opening on one side in the predetermined direction, the moving member protruding from the interior of the threaded receiving portion to the exterior of the threaded receiving portion via the opening portion, the inner surface of the threaded receiving portion having a support surface supporting the rotating member or the moving member, the path portion having at least one of a groove portion and a hole portion, and connecting a space located on the other side of the predetermined direction of the moving member when it moves in the predetermined direction to an external space located on one side of the predetermined direction of the threaded receiving portion.

[0117] (2) The electric actuator according to (1), wherein the path portion has an extension path portion extending in the predetermined direction, the extension path portion being formed by a slot or a hole.

[0118] (3) The electric actuator according to (2), wherein the extension path portion is formed by a groove provided on the inner surface of the first cylindrical portion and opening on one side in the predetermined direction, and the inner surface of the extension path portion is connected to the support surface.

[0119] (4) The electric actuator according to any one of (1) to (3), wherein the moving member has a second cylindrical portion that opens on the other side of the predetermined direction, the second cylindrical portion having a second threaded portion on its inner circumferential surface, the rotating member being a shaft extending in the predetermined direction and having a first threaded portion on its outer circumferential surface, and at least a portion of the rotating member being located inside the second cylindrical portion.

[0120] (5) The electric actuator according to (4), wherein the threaded receiving portion has: a small diameter portion having the support surface; and a large diameter portion located on the other side of the small diameter portion in the predetermined direction, wherein the inner diameter of the large diameter portion is larger than the inner diameter of the small diameter portion.

[0121] (6) The electric actuator according to any one of (1) to (3), wherein the rotating member has a third cylindrical portion that opens on one side in the predetermined direction, the third cylindrical portion having a first threaded portion on its inner circumferential surface, the moving member being a shaft extending in the predetermined direction and having a second threaded portion on its outer circumferential surface, at least a portion of the moving member being located inside the third cylindrical portion, and the path portion having a portion consisting of a hole through which the third cylindrical portion extends from the inner circumferential surface to the outer circumferential surface.

[0122] (7) The electric actuator according to any one of (1) to (6) includes: a sealing member that seals the inner surface of the first cylindrical portion with the rotating member, the sealing member being located on the other side of the moving member in the predetermined direction.

[0123] (8) The electric actuator according to any one of (1) to (7) includes: a reduction mechanism connected to the rotor of the motor, wherein rotation of the rotor is transmitted to the rotating member via the reduction mechanism.

[0124] (9) The electric actuator according to any one of (1) to (7), wherein the rotating member is the motor shaft of the motor.

[0125] The configurations and methods described above in this specification can be appropriately combined within the scope of not contradicting each other.

Claims

1. An electric actuator comprising: a motor; a rotating member that is rotated by the motor, the rotating member having a first threaded portion; a moving member that has a second threaded portion engaged with the first threaded portion, the moving member moving in a prescribed direction as the rotating member rotates; a housing having a first cylindrical portion extending in the prescribed direction; and a path portion, at least a portion of the path portion being provided in the housing, the first cylindrical portion having a threaded accommodation portion that accommodates at least a portion of the first threaded portion and at least a portion of the second threaded portion inside, the threaded accommodation portion having an opening portion that is open on one side in the prescribed direction, the moving member protruding from inside the threaded accommodation portion to outside the threaded accommodation portion via the opening portion, an inner surface of the threaded accommodation portion having a support surface that supports the rotating member or the moving member, the path portion having at least one of a portion composed of a groove and a portion composed of a hole, and connecting a space on the other side in the prescribed direction of the moving member when the moving member moves in the prescribed direction and an outside space on one side in the prescribed direction of the threaded accommodation portion.

2. The electric actuator according to claim 1, wherein the path portion has an extended path portion extending in the prescribed direction, and the extended path portion is composed of a groove or a hole.

3. The electric actuator according to claim 2, wherein the extended path portion is composed of a groove provided in an inner surface of the first cylindrical portion and open on one side in the prescribed direction, and an inner surface of the extended path portion is connected to the support surface.

4. The electric actuator according to claim 1, wherein the moving member has a second cylindrical portion open on the other side in the prescribed direction, the second cylindrical portion has the second threaded portion in an inner peripheral surface, the rotating member is a shaft extending in the prescribed direction and has the first threaded portion in an outer peripheral surface, and at least a portion of the rotating member is located inside the second cylindrical portion.

5. The electric actuator according to claim 4, wherein the threaded accommodation portion has: a small-diameter portion having the support surface; and a large-diameter portion located at the other side in the prescribed direction than the small-diameter portion, an inner diameter of the large-diameter portion being larger than an inner diameter of the small-diameter portion.

6. The electric actuator according to claim 1, wherein the rotating member has a third cylindrical portion open on one side in the prescribed direction, the third cylindrical portion has the first threaded portion in an inner peripheral surface, the moving member is a shaft extending in the prescribed direction and has the second threaded portion in an outer peripheral surface, at least a portion of the moving member is located inside the third cylindrical portion, and the path portion has a portion composed of a hole that penetrates the third cylindrical portion from the inner peripheral surface to the outer peripheral surface.

7. The electric actuator according to claim 1, comprising a sealing member that seals between an inner surface of the first cylindrical portion and the rotating member. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The sealing member is located at the other side of the moving member than the prescribed direction.

8. The electric actuator according to any one of claims 1 to 7, wherein The electric actuator is provided with a reduction mechanism connected to a rotor of the motor, Rotation of the rotor is transmitted to the rotating member via the reduction mechanism.

9. The electric actuator according to any one of claims 1 to 7, wherein The rotating member is a motor shaft of the motor.

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