Electric actuator

Abstract

The utility model provides an electric actuator which can realize miniaturization. An electric actuator is provided with a motor having a rotor and a stator, a transmission mechanism, and a housing, the housing having: a cylindrical housing main body having an opening and a main body side wall part; and a cover member having a cover side wall portion and covering the opening portion, a main body side wall surface, which is a surface of the main body side wall portion facing one side in the radial direction, and a cover side wall surface, which is a surface of the cover side wall portion facing the other side in the radial direction, face each other in the radial direction, and one of the main body side wall surface and the cover side wall surface is provided with a first circumferential groove. The housing has a first peripheral groove that is recessed in the radial direction with respect to the other of the body-side wall surface and the cover-side wall surface and extends over a circle in a direction orthogonal to the axial direction, and has a connection hole that connects a space formed by the first peripheral groove and the other of the body-side wall surface and the cover-side wall surface to an external space of the housing. The space part is filled with a sealing material for sealing the space between the main body side wall part and the cover side wall part.

Description

Technical Field

[0001] The utility model relates to an electric actuator. Background Art

[0002] There is known an actuator including a housing composed of a plurality of parts (for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-231834 Utility Model Content

[0006] Issues to be Solved by Utility Models

[0007] In the above-mentioned actuator, when the mutually opposing surfaces of the multiple components are sealed by elastic components such as O-rings, a groove for accommodating the elastic component needs to be provided on the opposing surface of at least one component. Therefore, the size of the opposing surface of one component tends to become larger, and there is a concern that the actuator may become larger.

[0008] In view of the above situation, one of the objects of the present invention is to provide an electric actuator that can be miniaturized.

[0009] Solutions to Solve Problems

[0010] The electric actuator of scheme 1 of the present invention is characterized in that it comprises: a motor, which has: a rotor, which has a motor shaft that can rotate around the motor axis; and a stator, which is arranged on the radial outside of the rotor; a transmission mechanism, which reduces the speed of rotation of the motor shaft and transmits it to an output shaft; and a housing, which respectively accommodates the motor and the transmission mechanism, the housing having: a cylindrical housing body, which has an opening portion opened to one axial side and a main body side wall portion extending in the axial direction; and a cover component, which has a cover side wall portion extending in the axial direction and covering the opening portion, and the surface of the main body side wall portion facing the radial side, namely the main body side wall The surface is radially opposed to the surface of the cover side wall portion facing the other radial side, namely the cover side wall surface, and a first circumferential groove is provided on one of the main body side wall surface and the cover side wall surface. The first circumferential groove is radially recessed relative to the other of the main body side wall surface and the cover side wall surface, and extends all around in a direction orthogonal to the axial direction. The shell has a connecting hole, which connects a space portion formed by the first circumferential groove and the other of the main body side wall surface and the cover side wall surface with an external space of the shell, and in the space portion, a sealing material is filled all around to seal the space between the main body side wall portion and the cover side wall portion.

[0011] The electric actuator of scheme 2 of the utility model is characterized in that, when viewed in the axial direction, the side wall surface of the main body has a main body corner portion bent into an angle, and when viewed in the axial direction, the side wall surface of the cover is bent into an angle and has a cover corner portion radially opposite to the main body corner portion.

[0012] The electric actuator according to claim 3 of the present invention is characterized in that, when viewed in the axial direction, a plurality of the connection holes are arranged at intervals along the direction in which the space portion extends.

[0013] The electric actuator according to claim 4 of the present invention is characterized in that two of the plurality of connection holes are arranged at positions sandwiching the motor axis in the radial direction.

[0014] The electric actuator of scheme 5 of the utility model is characterized in that the space portion has: a first space portion, which passes through a side of a first direction orthogonal to the axial direction that is closer to the motor axis; and a second space portion, which passes through the other side of the first direction that is closer to the motor axis, the multiple connecting holes include a first connecting hole and a second connecting hole, the first space portion and the second space portion respectively connect the first connecting hole and the second connecting hole, and the length of the first space portion is the same as the length of the second space portion.

[0015] The electric actuator according to claim 6 of the present invention is characterized in that, when viewed in the axial direction, the first space portion and the second space portion are line-symmetrically shaped with respect to a straight line passing through the first connection hole and the second connection hole as a symmetry line.

[0016] The electric actuator according to claim 7 of the present invention is characterized in that the first circumferential groove is provided on a surface facing radially outward among the body side wall surface and the cover side wall surface.

[0017] The electric actuator according to claim 8 of the present invention is characterized in that a sealing material is filled inside the connecting hole.

[0018] The electric actuator of scheme 9 of the utility model is characterized in that a second circumferential groove is provided on the other side of the main body side wall surface and the cover side wall surface, the second circumferential groove is radially recessed, extends all around in a direction orthogonal to the axial direction, and is radially opposite to the first circumferential groove, the space portion is composed of the first circumferential groove and the second circumferential groove, and the sealing material is filled in a manner spanning the interior of the first circumferential groove and the interior of the second circumferential groove.

[0019] Effect of utility model

[0020] According to one aspect of the present invention, the electric actuator can be downsized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a perspective view showing the electric actuator according to the first embodiment.

[0022] Figure 2 It is a cross-sectional view showing the electric actuator according to the first embodiment.

[0023] Figure 3 It is a plan view showing a part of the electric actuator according to the first embodiment.

[0024] Figure 4 is a cross-sectional view showing the electric actuator of the first embodiment. Figure 2 IV-IV cross-sectional view.

[0025] Figure 5 This is an enlarged cross-sectional view showing a part of the electric actuator according to the first embodiment.

[0026] Figure 6 This is a first cross-sectional view showing a cover member fixing step of the electric actuator according to the first embodiment.

[0027] Figure 7 This is a second cross-sectional view showing the cover member fixing step of the electric actuator according to the first embodiment.

[0028] Figure 8 It is a cross-sectional view showing an electric actuator according to a second embodiment.

[0029] In the figure:

[0030] 1. 101—electric actuator; 9—motor; 10. 110—housing; 11. 111—housing body; 12b—opening; 13. 113—body side wall; 13d. 113d—body side wall surface; 13m. 13n—body corner; 14—second circumferential groove; 16—cover component; 17—cover side wall; 17d—cover side wall surface; 17m. 17n—cover corner; 19. 119—connecting hole; 19a. 119a—first connecting hole; 19b. 119b—second connecting hole; 20—rotor; 23—motor shaft; 30—stator; 18—first circumferential groove; 50. 150—space; 50a—first space; 50b—second space; 55. 155—sealing material; 60—transmission mechanism; 66—output shaft; D1—first direction; J1—motor axis. DETAILED DESCRIPTION

[0031] In each drawing, the Z-axis direction is an up-down direction with the positive side (+Z side) being the upper side and the negative side (-Z side) being the lower side. In this embodiment, the upper side (+Z side) corresponds to one axial side and the lower side (-Z side) corresponds to the other axial side.

[0032] In each of the drawings, the first direction D1 is a direction orthogonal to the Z-axis direction. In the present embodiment, the first direction D1 is the front-rear direction of the electric actuator. In the following description, the side to which the arrow of the first direction D1 points (+D1 side) is referred to as the "front side" or "one side of the first direction D1", and the side opposite to the side to which the arrow of the first direction D1 points (-D1 side) is referred to as the "rear side" or "the other side of the first direction D1".

[0033] In each of the accompanying drawings, the second direction D2 is a direction orthogonal to both the Z-axis direction and the first direction D1. In the present embodiment, the second direction D2 is the left-right direction of the electric actuator. In the following description, the side to which the arrow of the second direction D2 points (+D2 side) is referred to as the "right side", and the side opposite to the side to which the arrow of the second direction D2 points (-D2 side) is referred to as the "left side". It should be noted that the upper side, lower side, front side, rear side, left side and right side are names used only to illustrate the relative positional relationship of each part, and the actual configuration relationship, etc. may also be a configuration relationship other than the configuration relationship indicated by these names, etc.

[0034] The direction in which the motor axis J1 shown in each figure extends is parallel to the Z-axis direction, that is, the up-down direction. The motor axis J1 is a virtual axis. In the following description, the direction parallel to the motor axis J1 is referred to as the "axial direction". The radial direction centered on the motor axis J1 is referred to as the "radial direction". The circumferential direction centered on the motor axis J1 is referred to as the "circumferential direction".

[0035] In each of the drawings, the circumferential direction is indicated by an arrow θ1. The side in the circumferential direction toward which the arrow θ1 points is referred to as the "circumferential one side". The side in the circumferential direction opposite to the side in which the arrow θ1 points is referred to as the "circumferential other side". The circumferential one side is the side that moves clockwise around the motor axis J1 when viewed from the upper side. The circumferential other side is the side that moves counterclockwise around the motor axis J1 when viewed from the axial side.

[0036] In the following description, "radially outward" also includes the case where, when a direction is decomposed into a component facing radially and a component facing circumferentially, the component facing radially faces radially outward. Similarly, "radially inward" also includes the case where, when a direction is decomposed into a component facing radially and a component facing circumferentially, the component facing radially faces radially inward. In addition, "one circumferential side" also includes the case where, when a direction is decomposed into a component facing radially and a component facing circumferentially, the component facing circumferentially faces one circumferential side. Similarly, "the other circumferential side" also includes the case where, when a direction is decomposed into a component facing radially and a component facing circumferentially, the component facing circumferentially faces the other circumferential side. In addition, in the following description, "one radial side" refers to the direction in which the side wall surface of the main body faces, and "the other radial side" refers to the direction in which the side wall surface of the cover faces. "One radial side" is either "the inner radial side" or "the outer radial side", and "the other radial side" is the other of "the inner radial side" or "the outer radial side".

[0037] <First embodiment>

[0038] Figure 1 The electric actuator 1 of the present embodiment shown in FIG. 1 is mounted on a vehicle. More specifically, the electric actuator 1 is mounted on, for example, an actuator device of a parking-by-wire system that is driven based on a shift operation by a driver of the vehicle. Figure 2 As shown, the electric actuator 1 includes a housing 10 , a motor 9 , a stator cover 40 , a transmission mechanism 60 , an output shaft 66 , and a circuit board 80 .

[0039] The housing 10 accommodates the motor 9, the stator cover 40, the transmission mechanism 60, the output shaft 66 and the circuit substrate 80 inside. The housing 10 has a housing body 11, a cover member 16, a space portion 50 and a connecting hole 19. The housing body 11 is in the shape of a tube surrounding the motor axis J1. The housing body 11 has an opening portion 12b that opens to the upper side, i.e., one axial side. The housing body 11 has a peripheral wall portion 12, a main body side wall portion 13, a bottom wall portion 15, and a connector portion 12m. The main body side wall portion 13 is arranged on the upper side of the peripheral wall portion 12. The peripheral wall portion 12 is connected to the main body side wall portion 13 in the axial direction. In the present embodiment, the housing body 11 is made of resin. The housing body 11 can also be made of metal.

[0040] The peripheral wall portion 12 is cylindrical and surrounds the motor axis J1. The peripheral wall portion 12 extends in the axial direction. The peripheral wall portion 12 surrounds the lower part of the motor 9 and the stator cover 40 from the radial outside. When viewed in the axial direction, the inner peripheral surface of the peripheral wall portion 12 is a circle centered on the motor axis J1. The peripheral wall portion 12 has a first positioning portion 12c, a first step surface 12d, a second positioning portion 12e, and a housing protrusion 12h.

[0041] The first positioning portion 12c is a step surface facing upward. The first positioning portion 12c is a portion of the inner surface of the peripheral wall portion 12. When viewed in the axial direction, the first positioning portion 12c is in the shape of an annulus centered on the motor axis J1. The first step surface 12d is a step surface facing upward. The first step surface 12d is a portion of the inner surface of the peripheral wall portion 12. When viewed in the axial direction, the first step surface 12d is in the shape of an annulus centered on the motor axis J1. The first step surface 12d is arranged at a position higher than the first positioning portion 12c. The inner diameter of the first step surface 12d is larger than the inner diameter of the first positioning portion 12c.

[0042] The second positioning portion 12e is cylindrical in shape, surrounding the motor axis J1 and extending in the axial direction. When viewed in the axial direction, the inner circumferential surface of the second positioning portion 12e is a circular shape centered on the motor axis J1. The second positioning portion 12e is a portion between the first positioning portion 12c and the first step surface 12d in the peripheral wall portion 12. The lower end of the inner circumferential surface of the second positioning portion 12e is connected to the radial outer edge of the first positioning portion 12c. The upper end of the inner circumferential surface of the second positioning portion 12e is connected to the radial inner edge of the first step surface 12d.

[0043] The housing protrusion 12h is cylindrical and protrudes upward from the edge of the right side (+D2 side) of the upward surface of the peripheral wall 12. An internal threaded hole recessed downward is provided on the upward surface of the housing protrusion 12h. Figure 3 As shown in FIG. 1 , in the present embodiment, two housing protrusions 12h are provided. The housing protrusions 12h are arranged at intervals in the first direction D1.

[0044] The bottom wall portion 15 is in the shape of a plate extending radially inward from the lower end of the peripheral wall portion 12. The bottom wall portion 15 is provided with a hole portion 15a and a bearing retaining portion 15b. The hole portion 15a is a hole that penetrates the bottom wall portion 15 in the axial direction. When viewed in the axial direction, the hole portion 15a is a circular shape centered on the motor axis J1. A filter component 95 is detachably mounted on the hole portion 15a. The filter component 95 is a filter that allows ventilation between the interior of the housing 10 and the exterior of the housing 10. An O-ring 96 is arranged between the filter component 95 and the inner side surface of the hole portion 15a. The O-ring 96 seals between the filter component 95 and the housing 10.

[0045] The bearing holding portion 15b protrudes upward from the bottom wall portion 15. The bearing holding portion 15b is in a cylindrical shape centered on the motor axis J1. The first bearing 91 is held on the inner peripheral surface of the bearing holding portion 15b. In the present embodiment, the first bearing 91 is a ball bearing.

[0046] The main body side wall portion 13 is in a cylindrical shape that surrounds the motor axis J1 and extends in the axial direction. The main body side wall portion 13 surrounds the circuit substrate 80 from the radially outer side. The main body side wall portion 13 is connected to the peripheral wall portion 12 in the axial direction. Figure 3As shown, the main body side wall portion 13 includes a first main body side wall portion 13a, a second main body side wall portion 13b and a main body side wall surface 13d. The main body side wall portion 13 is provided with a main body protrusion 13p.

[0047] The first main body side wall portion 13a is the left side (-D2 side) portion of the main body side wall portion 13. When viewed in the axial direction, the first main body side wall portion 13a is in a roughly semicircular arc shape centered on the motor axis J1. The second main body side wall portion 13b is the right side (+D2 side) portion of the main body side wall portion 13. When viewed in the axial direction, the second main body side wall portion 13b is in a roughly rectangular shape with the long side extending along the first direction D1. Figure 2 As shown, the right side portion of the inner side surface of the second main body side wall portion 13 b is located further to the right than the inner peripheral surface of the peripheral wall portion 12 .

[0048] like Figure 3 As shown, in this embodiment, the main body side wall surface 13d is the inner side surface of the main body side wall portion 13. The main body side wall surface 13d faces radially inward. In this embodiment, the radial side is the radially inward. The main body side wall surface 13d includes a first main body side wall surface 13e, a second main body side wall surface 13f, a third main body side wall surface 13g and a fourth main body side wall surface 13h. Figure 2 As shown, a second peripheral groove 14 is provided on the main body side wall surface 13d.

[0049] like Figure 3 As shown, the first main body side wall surface 13e is the inner side surface of the first main body side wall portion 13a. The first main body side wall surface 13e faces radially inward. When viewed in the axial direction, the first main body side wall surface 13e is roughly semicircular with the motor axis J1 as the center. The second main body side wall surface 13f is the surface facing the rear side (-D1 side) of the inner side surface of the second main body side wall portion 13b. The second main body side wall surface 13f faces radially inward. When viewed in the axial direction, the second main body side wall surface 13f is a straight line extending along the second direction D2. The end of the left side (-D2 side) of the second main body side wall surface 13f is connected to the end of the front side (+D1 side) of the first main body side wall surface 13e.

[0050] The third main body side wall surface 13g is a surface facing the front side (+D1 side) of the inner side surface of the second main body side wall portion 13b. The third main body side wall surface 13g faces radially inward. When viewed in the axial direction, the third main body side wall surface 13g is in a straight line extending along the second direction D2. The end of the left side (-D2 side) of the third main body side wall surface 13g is connected to the end of the rear side (-D1 side) of the first main body side wall surface 13e.

[0051] The fourth main body side wall surface 13h is the surface facing the left side (-D2 side) among the inner side surfaces of the second main body side wall portion 13b. The fourth main body side wall surface 13h faces radially inward. When viewed in the axial direction, the fourth main body side wall surface 13h is in the shape of a straight line extending along the first direction D1. The end of the front side (+D1 side) of the fourth main body side wall surface 13h is connected to the end of the right side (+D2 side) of the second main body side wall surface 13f. When viewed in the axial direction, the portion of the main body side wall surface 13d where the fourth main body side wall surface 13h is connected to the second main body side wall surface 13f is a main body corner portion 13m bent into an angle. The end of the rear side (-D1 side) of the fourth main body side wall surface 13h is connected to the end of the right side of the third main body side wall surface 13g. When viewed in the axial direction, the portion of the main body side wall surface 13d where the fourth main body side wall surface 13h is connected to the third main body side wall surface 13g is a main body corner portion 13n bent into an angle. That is, the main body side wall surface 13d has main body corners 13m and 13n. In the present embodiment, the internal angle of each of the main body corners 13m and 13n is approximately 90 degrees.

[0052] like Figure 2 As shown, the second circumferential groove 14 is a groove that is recessed radially from the main body side wall surface 13d. In more detail, the second circumferential groove 14 is recessed radially outward from the main body side wall surface 13d. The inner side surface of the second circumferential groove 14 is a part of the main body side wall surface 13d. When viewed in the circumferential direction, the second circumferential groove 14 is in a semicircular shape that protrudes radially outward. When viewed in the circumferential direction, the second circumferential groove 14 can also be in other shapes such as a rectangle or a triangle. The interior of the second circumferential groove 14 is filled with a sealing material 55. As shown in FIG. Figure 4 As shown, the second circumferential groove 14 extends around the entire circumference in a direction perpendicular to the axial direction.

[0053] like Figure 5 As shown in FIG. 1 , the main body protrusion 13p protrudes upward from the main body side wall portion 13. More specifically, the main body protrusion 13p protrudes upward from the radial inner edge of the main body side wall portion 13. Figure 3 As shown in FIG. 1 , the main body protrusion 13 p surrounds the motor axis J1 . The main body protrusion 13 p is provided along the main body side wall portion 13 over a circumference.

[0054] like Figure 2 As shown, the connector portion 12m is in a cylindrical shape protruding from the peripheral wall portion 12 to the right (+D2 side). The connector portion 12m holds a plurality of connector pins 12n. The plurality of connector pins 12n are electrically connected to the circuit board 80.

[0055] The cover member 16 is fixed to the upper end of the shell body 11. The cover member 16 covers the opening portion 12b of the shell body 11 from the upper side. The cover member 16 has a cover storage portion 16a, a flange portion 16d, a cover protrusion 16e and a cover side wall portion 17. The cover storage portion 16a is in the shape of a box that protrudes in the axial direction. The cover storage portion 16a is open to the lower side. The interior of the cover storage portion 16a is connected to the interior of the shell body 11 in the axial direction. The transmission mechanism 60 is stored in the interior of the cover storage portion 16a. Figure 1 As shown, when viewed in the axial direction, the left side (-D2 side) of the cover receiving portion 16a is in a substantially semicircular shape centered on the motor axis J1. When viewed in the axial direction, the right side (+D2 side) of the cover receiving portion 16a is in a substantially rectangular shape with the long side extending in the first direction D1. The cover receiving portion 16a is provided with a cover hole portion 16b.

[0056] The cover hole portion 16b is a hole that penetrates the cover housing portion 16a in the axial direction. When viewed in the axial direction, the cover hole portion 16b is a circular shape centered on the output axis J2. The output axis J2 is an imaginary axis extending in a direction parallel to the motor axis J1. The output axis J2 is located on the right side (+D2 side) of the motor axis J1. In the following description, the radial direction centered on the output axis J2 is referred to as the "output radial direction", and the circumferential direction centered on the output axis J2 is referred to as the "output circumferential direction". The output circumferential direction is indicated by the arrow θ2 in each of the accompanying drawings.

[0057] like Figure 2 As shown in FIG. 1 , the flange portion 16d is in the shape of a plate extending from the lower end of the cover receiving portion 16a in a direction perpendicular to the axial direction. When viewed in the axial direction, the outer edge of the flange portion 16d overlaps with the main body side wall portion 13. Figure 5 As shown, the outer edge of the flange portion 16d contacts the upper end of the main body protrusion 13p in the axial direction. The outer edge of the flange portion 16d is fixed to the main body side wall portion 13. Thus, the cover member 16 is fixed to the housing body 11. It should be noted that the cover member 16 and the housing body 11 can be fixed by fastening members such as bolts not shown in the figure, or can be fixed by heat welding.

[0058] like Figure 2 As shown in FIG. 1 , the cover protrusion 16e protrudes downward from the outer edge of the flange portion 16d. The cover protrusion 16e is provided all around the outer edge of the flange portion 16d. The cover protrusion 16e surrounds the motor axis J1. Figure 5 As shown, the cover protrusion 16e is arranged radially outward of the main body protrusion 13p.

[0059] like Figure 2 As shown in FIG. 1 , the cover side wall portion 17 is cylindrical and surrounds the motor axis J1 and extends in the axial direction. The cover side wall portion 17 extends downward from the flange portion 16d. Figure 5As shown, the cover side wall portion 17 is arranged radially inward of the main body side wall portion 13. The cover side wall portion 17 is in contact with the main body side wall portion 13 in the radial direction. The cover side wall portion 17 may not be in contact with the main body side wall portion 13. In addition, a portion of the cover side wall portion 17 may be in contact with a portion of the main body side wall portion 13. Figure 4 As shown, the cover side wall portion 17 includes a first cover side wall portion 17 a , a second cover side wall portion 17 b , and a cover side wall surface 17 d .

[0060] The first cover side wall portion 17a is a portion on the left side (-D2 side) of the cover side wall portion 17. When viewed in the axial direction, the first cover side wall portion 17a is in a substantially semicircular arc shape centered on the motor axis J1. The second cover side wall portion 17b is a portion on the right side (+D2 side) of the cover side wall portion 17. When viewed in the axial direction, the second cover side wall portion 17b is in a substantially rectangular shape with the long side extending in the first direction D1.

[0061] In this embodiment, the cover side wall surface 17d is the outer side surface of the cover side wall portion 17. The cover side wall surface 17d faces radially outward. In this embodiment, the other radial side is radially outward. The cover side wall surface 17d includes a first cover side wall surface 17e, a second cover side wall surface 17f, a third cover side wall surface 17g, and a fourth cover side wall surface 17h. Figure 5 As shown, a first peripheral groove 18 is provided on the cover side wall surface 17d.

[0062] like Figure 4 As shown, the first cover side wall surface 17e is the outer side surface of the first cover side wall portion 17a. The first cover side wall surface 17e faces radially outward. When viewed in the axial direction, the first cover side wall surface 17e is roughly semicircular with the motor axis J1 as the center. The first cover side wall surface 17e and the first main body side wall surface 13e are opposite in the radial direction. The first cover side wall surface 17e contacts the first main body side wall surface 13e in the radial direction.

[0063] The second cover side wall surface 17f is the surface facing the front side (+D1 side) among the outer side surfaces of the second cover side wall portion 17b. The second cover side wall surface 17f faces radially outward. When viewed in the axial direction, the second cover side wall surface 17f is a straight line extending along the second direction D2. The second cover side wall surface 17f is radially opposite to the second main body side wall surface 13f. The second cover side wall surface 17f is in radial contact with the second main body side wall surface 13f. The end of the left side (-D2 side) of the second cover side wall surface 17f is connected to the end of the front side of the first cover side wall surface 17e.

[0064] The third cover side wall surface 17g is the surface facing the rear side (-D1 side) among the outer side surfaces of the second cover side wall portion 17b. The third cover side wall surface 17g faces radially outward. When viewed in the axial direction, the third cover side wall surface 17g is a straight line extending along the second direction D2. The third cover side wall surface 17g is radially opposed to the third main body side wall surface 13g. The third cover side wall surface 17g is in radial contact with the third main body side wall surface 13g. The end of the left side (-D2 side) of the third cover side wall surface 17g is connected to the end of the rear side (-D1 side) of the first cover side wall surface 17e.

[0065] The fourth cover side wall surface 17h is the surface facing the right side (+D2 side) among the outer side surfaces of the second cover side wall portion 17b. The fourth cover side wall surface 17h faces radially outward. When viewed in the axial direction, the fourth cover side wall surface 17h is a straight line extending along the first direction D1. The fourth cover side wall surface 17h is radially opposite to the fourth main body side wall surface 13h. The fourth cover side wall surface 17h is in radial contact with the fourth main body side wall surface 13h. The end of the front side (+D1 side) of the fourth cover side wall surface 17h is connected to the end on the right side of the second cover side wall surface 17f. When viewed in the axial direction, the portion of the cover side wall surface 17d where the fourth cover side wall surface 17h is connected to the second cover side wall surface 17f is a cover corner portion 17m bent into an angle. The end of the rear side (-D1 side) of the fourth cover side wall surface 17h is connected to the end on the right side of the third cover side wall surface 17g. When viewed in the axial direction, the portion of the cover side wall surface 17d where the fourth cover side wall surface 17h and the third cover side wall surface 17g are connected is a cover corner portion 17n bent into an angle. That is, the cover side wall surface 17d has cover corner portions 17m and 17n. In this embodiment, the inner angles of the cover corner portions 17m and 17n are approximately 90°.

[0066] The cover corner portion 17m faces the main body corner portion 13m in the radial direction. The cover corner portion 17n faces the main body corner portion 13n in the radial direction. That is, the cover side wall surface 17d has the cover corner portions 17m and 17n facing the main body corner portions 13m and 13n in the radial direction.

[0067] As described above, the first cover side wall surface 17e, the second cover side wall surface 17f, the third cover side wall surface 17g, and the fourth cover side wall surface 17h are radially opposed to the first body side wall surface 13e, the second body side wall surface 13f, the third body side wall surface 13g, and the fourth body side wall surface 13h, respectively. That is, the body side wall surface 13d and the cover side wall surface 17d are radially opposed.

[0068] like Figure 5As shown, the first circumferential groove 18 is a groove that is radially recessed from the cover side wall surface 17d. In more detail, the first circumferential groove 18 is recessed radially inward from the cover side wall surface 17d. The first circumferential groove 18 is radially recessed relative to the main body side wall surface 13d. In the present embodiment, the first circumferential groove 18 is provided on the surface facing radially outward between the main body side wall surface 13d and the cover side wall surface 17d, namely, the cover side wall surface 17d. The first circumferential groove 18 is a part of the cover side wall surface 17d. When viewed in the circumferential direction, the first circumferential groove 18 is in the shape of a semicircle that protrudes radially inward. When viewed in the circumferential direction, the first circumferential groove 18 may also be in other shapes, such as a rectangle and a triangle. The interior of the first circumferential groove 18 is filled with a sealing material 55. As shown Figure 4 As shown, the first circumferential groove 18 extends around the entire circumference in a direction perpendicular to the axial direction.

[0069] like Figure 5 As shown, the second circumferential groove 14 is radially opposed to the first circumferential groove 18. Thus, the interior of the first circumferential groove 18 is radially connected to the interior of the second circumferential groove 14. The internal space of the first circumferential groove 18 and the internal space of the second circumferential groove 14 constitute a space portion 50. That is, the space portion 50 is constituted by the first circumferential groove 18 and the second circumferential groove 14. As described above, the second circumferential groove 14 is a part of the main body side wall surface 13d. Therefore, the space portion 50 is constituted by the first circumferential groove 18 and the main body side wall surface 13d. When viewed in the circumferential direction, the space portion 50 is a circular space. As shown in FIG. Figure 4 As shown in FIG. 1 , the space portion 50 extends all around in a direction perpendicular to the axial direction. Figure 2 As shown, the space 50 is filled with a sealing material 55. The sealing material 55 is filled in a manner that spans the inside of the first peripheral groove 18 and the inside of the second peripheral groove 14. Thus, the sealing material 55 seals between the main body side wall portion 13 and the cover side wall portion 17. Figure 4 As shown in FIG. 1 , the space portion 50 is filled with a sealing material 55 all around. Therefore, the sealing material 55 seals all around between the body side wall portion 13 and the cover side wall portion 17. In addition, in this embodiment, as the sealing material 55, for example, a thermosetting liquid sealing material having elasticity, such as a silicone gasket and an acrylic gasket, can be used.

[0070] like Figure 2 As shown, in the present embodiment, the connection hole 19 is provided in the main body side wall portion 13. The connection hole 19 is a hole that penetrates the main body side wall portion 13 in the radial direction. The connection hole 19 is connected to the second circumferential groove 14. The connection hole 19 is a hole that extends radially outward from the space portion 50. Thus, the connection hole 19 connects the space portion 50 with the external space of the shell 10. Although omitted from the illustration, when viewed in the radial direction, the connection hole 19 is circular. When viewed in the radial direction, the connection hole 19 may also be other shapes such as a rectangle or a triangle. As shown in FIG. Figure 4As shown, in this embodiment, the housing 10 has a plurality of connection holes 19. The housing 10 has two connection holes 19. The plurality of connection holes 19 include a first connection hole 19a and a second connection hole 19b. It should be noted that the housing 10 may also have more than three connection holes 19.

[0071] The first connection hole 19a is provided at the edge of the left side (-D2 side) of the first main body side wall portion 13a. The first connection hole 19a connects the space portion 50 with the external space of the housing 10. The second connection hole 19b is provided at the edge of the right side (+D2 side) of the second main body side wall portion 13b. That is, a plurality of connection holes 19 are arranged at intervals along the direction in which the space portion 50 extends. The second connection hole 19b connects the space portion 50 with the external space of the housing 10. The two connection holes 19a and 19b are arranged at positions that clamp the motor axis J1 in the radial direction. The interior of the first connection hole 19a and the interior of the second connection hole 19b are filled with sealing material 55. That is, the interior of the connection hole 19 is filled with sealing material 55.

[0072] The space portion 50 has a first space portion 50a and a second space portion 50b. The first space portion 50a and the second space portion 50b are connected to the first connection hole 19a and the second connection hole 19b, respectively. The first space portion 50a extends from the first connection hole 19a toward the other side (-θ1 side) in the circumferential direction, and is connected to the second connection hole 19b. The first space portion 50a is a portion of the space portion 50 that passes through a position that is further forward than the motor axis J1, that is, one side (+D1 side) of the first direction D1. The second space portion 50b extends from the first connection hole 19a toward one side (+θ1 side) in the circumferential direction, and is connected to the second connection hole 19b. The second space portion 50b is a portion of the space portion 50 that passes through a position that is further rearward than the motor axis J1, that is, the other side (-D1 side) of the first direction D1. In this embodiment, the length of the first space portion 50a, that is, the length of the first space portion 50a from the part connected to the first connection hole 19a to the part connected to the second connection hole 19b, is the same as the length of the second space portion 50b, that is, the length of the second space portion 50b from the part connected to the first connection hole 19a to the part connected to the second connection hole 19b.

[0073] Figure 4 The first imaginary line L1 shown is an imaginary straight line passing through the first connection hole 19a and the second connection hole 19b. In this embodiment, when viewed in the axial direction, the first space portion 50a and the second space portion 50b are in a shape that is line symmetrical to each other with the first imaginary line L1 as a symmetry line. When viewed in the axial direction, the portion of the first space portion 50a that overlaps with the main body corner portion 13m and the cover corner portion 17m is bent into an angle shape. When viewed in the axial direction, the portion of the second space portion 50b that overlaps with the main body corner portion 13n and the cover corner portion 17n is bent into an angle shape.

[0074] like Figure 2 As shown, the motor 9 has a rotor 20 and a stator 30. The rotor 20 is rotatable around the motor axis J1. The rotor 20 has a rotor core 21, a magnet (not shown) and a motor shaft 23. The rotor core 21 is annular centered around the motor axis J1. The rotor core 21 is housed inside the peripheral wall portion 12. The magnet (not shown) is fixed to the rotor core 21. In this embodiment, a plurality of magnets are arranged at intervals in the circumferential direction.

[0075] The motor shaft 23 is rotatable around the motor axis J1. The motor shaft 23 is substantially cylindrical and extends axially around the motor axis J1. The motor shaft 23 extends across the interior of the peripheral wall 12, the interior of the main body side wall 13, and the interior of the cover storage portion 16a. The motor shaft 23 passes through the interior of the rotor core 21 in the axial direction. The rotor core 21 is fixed to the outer peripheral surface of the motor shaft 23. The motor shaft 23 is supported by the first bearing 91 and the second bearing 92 so as to be rotatable around the motor axis J1.

[0076] The stator 30 is arranged radially outside the rotor 20. The stator 30 is arranged to face the rotor 20 with a gap therebetween in the radial direction. The stator 30 is accommodated inside the peripheral wall portion 12. The stator 30 includes a stator core 31, an insulator 32, and a coil portion 35.

[0077] The stator core 31 is in an annular shape that surrounds the rotor core 21 from the radial outside. The stator core 31 is opposite to the rotor 20 with a gap in the radial direction. The stator core 31 has a core back 31a and a plurality of teeth 31b. The core back 31a is in an annular shape centered on the motor axis J1. The core back 31a is fixed to the second positioning portion 12e of the housing body 11. The surface of the core back 31a facing the lower side is in axial contact with the first positioning portion 12c. Thus, the axial position of the stator 30 relative to the housing body 11 is determined. A plurality of teeth 31b protrude radially inward from the core back 31a. The teeth 31b are arranged at intervals in the circumferential direction. The insulator 32 is mounted on the stator core 31. The insulator 32 insulates the stator core 31 from the coil portion 35.

[0078] The coil portion 35 includes a plurality of coil main bodies 35a and coil lead wires 35b. Each coil main body 35a is attached to the teeth 31b via an insulator 32. The coil lead wires 35b are drawn upward from the coil main body 35a and connected to the circuit board 80. Thus, the coil portion 35 is electrically connected to the circuit board 80.

[0079] The circuit substrate 80 is in the shape of a plate extending in a direction perpendicular to the axial direction. The circuit substrate 80 is arranged above the stator 30. The circuit substrate 80 is accommodated inside the main body side wall portion 13. The circuit substrate 80 is provided with a first substrate hole 80a, a second substrate hole 80b, a third substrate hole 80c, and a fourth substrate hole 80d. The first substrate hole 80a, the second substrate hole 80b, the third substrate hole 80c, and the fourth substrate hole 80d are holes that penetrate the circuit substrate 80 in the axial direction.

[0080] When viewed in the axial direction, the first substrate hole 80a is in a generally circular shape centered on the motor axis J1. The motor shaft 23 passes through the first substrate hole 80a in the axial direction. When viewed in the axial direction, the second substrate hole 80b is in a generally circular shape. Although not shown in the figure, three second substrate holes 80b are provided in the circuit substrate 80. One second substrate hole 80b is provided at the edge of the left side (-D2 side) of the circuit substrate 80. Although not shown in the figure, the other two second substrate holes 80b are arranged across the motor axis J1 in the first direction D1.

[0081] The third substrate hole 80c is provided at the edge of the right side (+X side) of the circuit substrate 80. When viewed in the axial direction, the third substrate hole 80c is roughly circular. Although not shown in the figure, two third substrate holes 80c are provided in the circuit substrate 80. Each third substrate hole 80c is arranged at intervals in the first direction D1. The periphery of each third substrate hole 80c is supported from the bottom by the shell protrusion 12h of the shell body 11. Thus, the axial position of the circuit substrate 80 relative to the shell body 11 is determined. When the screw 98 passes through each third substrate hole 80c in the axial direction and is screwed into the internal threaded hole of the shell protrusion 12h, the circuit substrate 80 is fixed to the shell body 11. When viewed in the axial direction, the fourth substrate hole 80d is roughly circular with the output axis J2 as the center. The output shaft 66 passes through the fourth substrate hole 80d in the axial direction.

[0082] The transmission mechanism 60 is arranged on the upper side of the circuit substrate 80. The transmission mechanism 60 is stored inside the cover storage portion 16a. The transmission mechanism 60 is connected to the motor shaft 23 and the output shaft 66. The transmission mechanism 60 transmits the rotation of the motor shaft 23 to the output shaft 66. In the present embodiment, the transmission mechanism 60 decelerates the rotation of the rotor 20 and transmits it to the output shaft 66. The transmission mechanism 60 can increase the speed of the rotation of the rotor 20 and transmit it to the output shaft 66, or it can transmit the rotation of the same rotation speed as the rotation of the rotor 20 to the output shaft 66. The transmission mechanism 60 has a motor gear 61, a first-stage gear 62, a second-stage gear 63, and an output gear 64. The rotation of the motor shaft 23 is transmitted to the motor gear 61, the first-stage gear 62, the second-stage gear 63, the output gear 64, and the output shaft 66 in sequence.

[0083] The motor gear 61 transmits the rotation of the motor shaft 23 to the first-stage gear 62. The motor gear 61 is in the shape of an annular plate centered on the motor axis J1. The inner circumferential surface of the motor gear 61 is fixed to the upper end of the motor shaft 23. Thus, the motor gear 61 rotates around the motor axis J1 together with the motor shaft 23. A motor gear portion is provided on the radially outward surface of the motor gear 61.

[0084] The first stage gear 62 transmits the rotation of the motor gear 61 to the second stage gear 63. The first stage gear 62 is in the shape of an annular plate centered on the output axis J2. The output shaft 66 passes through the interior of the first stage gear 62 in the axial direction. The first stage gear 62 is supported by the output shaft 66 so as to be rotatable around the output axis J2. The first stage gear 62 has a first large diameter gear 62a and a first small diameter gear 62b. The first large diameter gear 62a and the first small diameter gear 62b are part of the same single component.

[0085] The first large diameter gear 62a is in the shape of an annular plate centered on the output axis J2. The first large diameter gear 62a is radially opposed to the motor gear 61. A first large diameter gear portion is provided on the surface of the first large diameter gear 62a facing the radial outer side of the output. The first large diameter gear portion is meshed with the motor gear portion. The number of teeth of the first large diameter gear portion is greater than the number of teeth of the motor gear portion. Thus, the rotation of the motor shaft 23 and the motor gear 61 is decelerated and transmitted to the first-stage gear 62. The first small diameter gear 62b is in the shape of an annular plate centered on the output axis J2. The first small diameter gear 62b is arranged on the lower side of the first large diameter gear 62a. A first small diameter gear portion is provided on the surface of the first small diameter gear 62b facing the radial outer side of the output.

[0086] The second stage gear 63 transmits the rotation of the first stage gear 62 to the output gear 64. The second stage gear 63 is in the shape of an annular plate centered on the motor axis J1. The motor shaft 23 passes through the interior of the second stage gear 63 in the axial direction. The second stage gear 63 is supported by the motor shaft 23 so as to be rotatable around the motor axis J1. The second stage gear 63 has a second large diameter gear 63a and a second small diameter gear 63b. The second large diameter gear 63a and the second small diameter gear 63b are part of the same single component.

[0087] The second large diameter gear 63a is in the shape of an annular plate centered on the motor axis J1. The second large diameter gear 63a is radially opposed to the first small diameter gear 62b. A second large diameter gear portion is provided on the radially outward surface of the second large diameter gear 63a. The second large diameter gear portion meshes with the first small diameter gear portion. The number of teeth of the second large diameter gear portion is greater than the number of teeth of the first small diameter gear portion. Thus, the rotation of the first stage gear 62 is decelerated and transmitted to the second stage gear 63. The second small diameter gear 63b is in the shape of an annular plate centered on the motor axis J1. The second small diameter gear 63b is arranged on the lower side of the second large diameter gear 63a. A second small diameter gear portion is provided on the radially outward surface of the second small diameter gear 63b.

[0088] The output gear 64 transmits the rotation of the second-stage gear 63 to the output shaft 66. The output gear 64 is in the shape of an annular plate centered on the output axis J2. The inner circumferential surface of the output gear 64 is fixed to the output shaft 66. Thus, the output shaft 66 rotates together with the output gear 64 around the output axis J2. An output gear portion is provided on the surface of the output gear 64 facing the output radial outer side. The output gear portion meshes with the second small-diameter gear portion. The number of teeth of the output gear portion is larger than the number of teeth of the second small-diameter gear portion. Thus, the rotation of the second-stage gear 63 is decelerated and transmitted to the output gear 64. As described above, the rotation of the motor gear 61 is decelerated and transmitted to the first-stage gear 62, and the rotation of the first-stage gear 62 is decelerated and transmitted to the second-stage gear 63. Thus, the transmission mechanism 60 decelerates the rotation of the motor shaft 23 and transmits it to the output shaft 66.

[0089] The output shaft 66 outputs the driving force of the electric actuator 1. The output shaft 66 is in a generally cylindrical shape extending axially with the output axis J2 as the center. The output shaft 66 can rotate around the output axis J2. The output shaft 66 passes through the first-stage gear 62 and the output gear 64 in the axial direction. The output shaft 66 passes through the fourth substrate hole 80d of the circuit substrate 80 in the axial direction. The upper part of the output shaft 66 passes through the cover hole portion 16b in the axial direction. The output shaft 66 is supported by the inner circumferential surface of the cover hole portion 16b so as to be rotatable around the output axis J2. The lower part of the output shaft 66 is supported by the third bearing 93 so as to be rotatable around the output axis J2. The upper end of the output shaft 66 is exposed to the outside of the housing 10. The portion including the upper end of the output shaft 66 is connected to a driven component not shown. Thus, the electric actuator 1 can drive the driven component. In the present embodiment, as described above, the transmission mechanism 60 decelerates the rotation of the motor shaft 23 and transmits it to the output shaft 66. Therefore, the electric actuator 1 can increase the rotational torque of the output shaft 66 relative to the rotational torque of the motor shaft 23 , and thus can smoothly drive the driven member.

[0090] The stator cover 40 is in the shape of a plate extending in a direction perpendicular to the axial direction. The stator cover 40 is arranged inside the peripheral wall portion 12. The stator cover 40 is arranged on the upper side of the stator 30. The stator cover 40 is arranged on the lower side of the circuit substrate 80. In the present embodiment, the stator cover 40 is made of resin. The stator cover 40 may also be made of metal. The stator cover 40 has a cover body portion 41 and a cover fixing portion 42.

[0091] The cover body 41 is in the shape of a plate extending in a direction orthogonal to the axial direction. The cover body 41 is in the shape of a circular ring plate centered on the motor axis J1. The cover body 41 has a first cover hole 41b, a second cover hole 41f, a third cover hole 41h, a cover recess 41e, and a protrusion 41i. The first cover hole 41b, the second cover hole 41f, and the third cover hole 41h are each a hole that penetrates the cover body 41.

[0092] When viewed in the axial direction, the first cover hole portion 41b is in a circular shape centered on the motor axis J1. The motor shaft 23 passes through the first cover hole portion 41b in the axial direction. When viewed in the axial direction, the second cover hole portion 41f is in a circular shape. The coil lead wire 35b passes through the second cover hole portion 41f in the axial direction. When viewed in the axial direction, the third cover hole portion 41h is in a circular shape centered on the output axis J2. The output shaft 66 passes through the third cover hole portion 41h in the axial direction. A third bearing 93 is installed in the third cover hole portion 41h. The third bearing 93 supports the lower part of the output shaft 66 so that it can rotate around the output axis J2. In the present embodiment, the third bearing 93 is a sliding bearing. The third bearing 93 may also be a ball bearing.

[0093] The cover recess 41e is recessed upward from the downward surface of the cover body 41. The cover recess 41e extends circumferentially around the motor axis J1. The upper portion of the insulator 32 and the upper portions of the plurality of coil bodies 35a are disposed inside the cover recess 41e.

[0094] The protrusion 41i is cylindrical and protrudes upward from the cover body 41. Although not shown in the figure, in the present embodiment, the cover body 41 has three protrusions 41i. An internal threaded hole that is recessed downward from the surface of each protrusion 41i facing upward is provided on each protrusion 41i. Each protrusion 41i supports the periphery of each second substrate hole 80b of the circuit substrate 80 from the lower side. Thus, the axial position of the circuit substrate 80 relative to the stator cover 40 is determined. As described later, the stator cover 40 is fixed to the housing body 11. Therefore, the axial position of the circuit substrate 80 relative to the housing body 11 is determined via the stator cover 40. When the screw 98 passes through each second substrate hole 80b in the axial direction and is screwed into the internal threaded hole of each protrusion 41i, the circuit substrate 80 is fixed to the stator cover 40. The circuit substrate 80 is fixed to the housing body 11 via the stator cover 40.

[0095] The cover fixing portion 42 protrudes downward from the radial outer edge of the cover main body 41. The cover fixing portion 42 is annular with the motor axis J1 as the center. The outer peripheral surface of the cover fixing portion 42 is fixed to the peripheral wall portion 12. Thus, the stator cover 40 is fixed to the housing body 11. The surface of the cover fixing portion 42 facing downward is in contact with the core back 31a of the stator core 31 in the axial direction. Thus, the axial position of the stator 30 relative to the housing body 11 is determined via the stator cover 40.

[0096] Next, the cover member fixing step Mf of the electric actuator 1 of the present embodiment is described. The cover member fixing step Mf is a part of the manufacturing process of the electric actuator 1. In the cover member fixing step Mf, the cover member 16 is fixed to the housing body 11, and the sealing material 55 is filled in the space portion 50. The cover member fixing step Mf includes: a first step S1 of installing the various parts of the electric actuator 1 such as the motor 9 and the transmission mechanism 60 to the housing body 11; a second step S2 of fixing the cover member 16 to the housing body 11; and a third step S3 of filling the sealing material 55 in the space portion 50. It should be noted that in this specification, "operators, etc." include operators and assembly devices, etc. who perform various operations of the cover member fixing step Mf. Each operation may be performed only by the operator, only by the assembly device, or by both the operator and the assembly device.

[0097] like Figure 6 As shown, in the first step S1, the operator or the like installs the various parts of the electric actuator 1, such as the motor 9, the transmission mechanism 60, and the output shaft 66, on the housing body 11 fixed to a jig or the like (not shown). The various parts of the electric actuator 1 are installed inside the housing body 11 through the opening 12b. When the various parts of the electric actuator 1 are installed on the housing body 11, the first step S1 is completed.

[0098] In the second step S2, the operator moves the cover member 16 from the upper side to the lower side of the housing body 11. At this time, the operator axially passes the output shaft 66 through the cover hole 16b of the cover member 16. In addition, the operator inserts the cover side wall 17 into the body side wall 13. Figure 8 As shown, if the operator moves the cover member 16 downward until the outer edge of the flange portion 16d of the cover member 16 contacts the main body protrusion 13p of the housing body 11 in the axial direction, the movement of the cover member 16 is stopped. At this time, the first circumferential groove 18 and the second circumferential groove 14 are radially opposed. Therefore, the space portion 50 is formed by the first circumferential groove 18 and the second circumferential groove 14. After that, the operator fixes the cover member 16 to the housing body 11. The cover member 16 can be fixed to the housing body 11 by fastening members such as bolts not shown in the figure, or can be fixed to the housing body 11 by heat welding. When the cover member 16 is fixed to the housing body 11, the second step S2 ends.

[0099] In the third step S3, the operator first inserts the nozzle of a filling jig (not shown) into the first connection hole 19a from the outside of the housing body 11. Then, the operator fills the space 50 with a liquid sealing material 55 (not shown) from the first connection hole 19a using the filling jig. Figure 4 As shown, the liquid sealing material 55 flowing into the space portion 50 from the first connection hole 19a flows toward the second connection hole 19b in the first space portion 50a and the second space portion 50b, respectively. Then, the liquid sealing material 55 flowing in the first space portion 50a and the second space portion 50b, respectively, reaches the second connection hole 19b and leaks out to the outside of the shell body 11 through the second connection hole 19b. When the operator etc. confirms that the liquid sealing material 55 leaks out to the outside of the shell body 11, the filling of the liquid sealing material 55 is completed. Then, if the operator etc. solidifies the liquid sealing material 55, the sealing material 55 is used to seal the body side wall portion 13 and the cover side wall portion 17. That is, the shell body 11 and the cover member 16 are sealed by the sealing material 55. When the solidification of the sealing material 55 is completed, the third step S3 is completed. When the third step S3 is completed, the cover member fixing process Mf is completed.

[0100] It should be noted that in this embodiment, as described above, after the cover part 16 is fixed to the shell body 11 in the second step S2, the liquid sealing material 55 is filled into the space portion 50 in the third step S3, but it is also possible to use the shell body 11 to hold the cover part 16 in the second step S2, and after the liquid sealing material 55 is filled into the space portion 50 in the third step S3, the cover part 16 is fixed to the shell body 11.

[0101] According to the present embodiment, the housing 10 includes: a cylindrical housing body 11 having a main body side wall portion 13 extending in the axial direction; and a cover member 16 having a cover side wall portion 17 extending in the axial direction and covering the opening portion 12b. A main body side wall surface 13d, which is a surface of the main body side wall portion 13 facing radially inward, i.e., one radial side, and a cover side wall surface 17d, which is a surface of the cover side wall portion 17 facing radially outward, i.e., the other radial side, are radially opposed to each other, and a first circumferential groove 18 is provided on the cover side wall surface 17d, which is recessed in the radial direction relative to the main body side wall surface 13d and extends all around in a direction orthogonal to the axial direction. The housing 10 includes a connection hole 19, which connects a space portion 50 formed by the first circumferential groove 18 and the main body side wall surface 13d to an external space of the housing 10, and a sealing material 55 is filled all around in the space portion 50 to seal between the main body side wall portion 13 and the cover side wall portion 17. In the case of a structure in which the main body side wall portion 13 and the cover side wall portion 17 are sealed by an elastic member such as an O-ring disposed in a groove on the axially oriented surface of the side wall portion of one of the main body side wall portion 13 or the cover side wall portion 17, it is necessary to press the axially oriented surface of the other side wall portion of the main body side wall portion 13 or the cover side wall portion 17 against the elastic member. Therefore, in the case of this structure, in order to ensure the rigidity of the one side wall portion, the radial dimension of the one side wall portion is likely to become large. Therefore, it is difficult to achieve miniaturization of the electric actuator 1. In contrast, the electric actuator 1 of the present embodiment is a structure in which the main body side wall portion 13 and the cover side wall portion 17 are sealed by a sealing material 55 filled in a space portion 50 formed by the first circumferential groove 18 recessed radially from the cover side wall surface 17d and the main body side wall surface 13d. Therefore, it is not necessary to press the main body side wall portion 13 and the cover side wall portion 17 against each other, so it is easy to reduce the force applied to the main body side wall portion 13 and the cover side wall portion 17. Therefore, it is easy to reduce the radial dimensions of the body side wall portion 13 and the cover side wall portion 17. Therefore, it is easy to reduce the radial dimensions of the body side wall portion 13 and the cover side wall portion 17, so that the electric actuator 1 can be miniaturized.

[0102] According to the present embodiment, the main body side wall surface 13d has main body corners 13m and 13n bent in an angular shape when viewed in the axial direction, and the cover side wall surface 17d has cover corners 17m and 17n bent in an angular shape and facing the main body corners 13m and 13n in the radial direction when viewed in the axial direction. In the case of a structure in which the main body side wall surface 13d and the cover side wall surface 17d are sealed by an elastic member such as an O-ring, it is difficult to form the elastic member in a shape along the bent corner, and the manufacturing cost of the elastic member is likely to increase. In contrast, in the present embodiment, after the liquid sealing material 55 is filled into the space portion 50 in the third step S3 of the cover member fixing process Mf, the liquid sealing material 55 is solidified, thereby forming the sealing material 55. Therefore, even if the main body side wall surface 13d and the cover side wall surface 17d each have a corner, the sealing material 55 in a shape along the corner can be easily formed. Therefore, the increase in the manufacturing cost of the electric actuator 1 can be suppressed.

[0103] According to the present embodiment, when viewed in the axial direction, a plurality of connection holes 19 are arranged at intervals along the direction in which the space portion 50 extends. Therefore, at least one connection hole 19, in the present embodiment, the first connection hole 19a, can be used as a filling hole for filling the space portion 50 with the liquid sealing material 55, and at least one connection hole 19, in the present embodiment, the second connection hole 19b, can be used as an exhaust hole for exhausting the air in the space portion 50 to the outside of the space portion 50. Therefore, when the liquid sealing material 55 is filled into the space portion 50, it is possible to suppress the air from being drawn into the liquid sealing material 55. Thus, it is possible to suppress the generation of pores in the cured sealing material 55, and thus it is possible to improve the sealing performance of the housing body 11 and the cover member 16.

[0104] According to the present embodiment, two of the plurality of connection holes 19 are arranged at positions sandwiching the motor axis J1 in the radial direction. Therefore, in the third step S3 of the cover member fixing process Mf, when the operator fills the space portion 50 with the liquid sealing material 55, after confirming that the liquid sealing material 55 leaks out from the second connection hole 19b used as the exhaust hole, the operator can stop filling the liquid sealing material 55. Thus, it is easy to fill the liquid sealing material 55 around the space portion 50. Therefore, the sealing performance of the housing body 11 and the cover member 16 can be improved.

[0105] According to the present embodiment, the space portion 50 includes a first space portion 50a passing through the front side of the motor axis J1, that is, one side (+D1 side) of the first direction D1, and a second space portion 50b passing through the rear side of the motor axis J1, that is, the other side (-D1 side) of the first direction D1, and the plurality of connection holes 19 include a first connection hole 19a and a second connection hole 19b, and the first space portion 50a and the second space portion 50b connect the first connection hole 19a and the second connection hole 19b, respectively, and the length of the first space portion 50a is the same as the length of the second space portion 50b. Therefore, in the third step S3 of the cover member fixing process Mf, the deviation in the timing at which the liquid sealing material 55 passing through the first space portion 50a and the liquid sealing material 55 passing through the second space portion 50b reach the second connection hole 19b can be reduced. Therefore, after confirming that the liquid sealing material 55 leaks out of the second connection hole 19b, the operator stops filling the liquid sealing material 55, thereby more appropriately filling the liquid sealing material 55 around the space 50. Therefore, the sealing performance between the housing body 11 and the cover member 16 can be further improved.

[0106] According to the present embodiment, when viewed in the axial direction, the first space portion 50a and the second space portion 50b have shapes that are line symmetrical to each other with the first imaginary line L1 being the line of symmetry, and the first imaginary line L1 is a straight line passing through the first connection hole 19a and the second connection hole 19b. Therefore, in the third step S3 of the cover member fixing process Mf, the difference in pressure loss of the liquid sealing material 55 flowing in the first space portion 50a and the second space portion 50b, respectively, can be reduced. Therefore, the difference in flow rate of the liquid sealing material 55 flowing in the first space portion 50a and the second space portion 50b, respectively, can be reduced. Therefore, the deviation in the timing at which the liquid sealing material 55 passing through the first space portion 50a and the liquid sealing material 55 passing through the second space portion 50b reach the second connection hole 19b, respectively, can be more appropriately reduced. Therefore, after confirming that the liquid sealing material 55 leaks out of the second connection hole 19b, the operator stops filling the liquid sealing material 55, thereby more appropriately filling the liquid sealing material 55 around the space 50. Therefore, the sealing performance between the housing body 11 and the cover member 16 can be further improved.

[0107] According to the present embodiment, the connection hole 19 is filled with the sealing material 55. Therefore, in the third step S3 of the cover member fixing process Mf, the operator can stop filling the liquid sealing material 55 into the space portion 50 after confirming that the liquid sealing material 55 has leaked from the second connection hole 19b. Thus, as described above, the liquid sealing material 55 can be more appropriately filled around the space portion 50. Therefore, the sealing performance between the housing body 11 and the cover member 16 can be further improved.

[0108] According to the present embodiment, the second circumferential groove 14 is provided on the main body side wall surface 13d, the second circumferential groove 14 is recessed in the radial direction, extends all around in a direction orthogonal to the axial direction, and is radially opposed to the first circumferential groove 18, the space portion 50 is composed of the first circumferential groove 18 and the second circumferential groove 14, and the sealing material 55 is filled in a manner spanning the inside of the first circumferential groove 18 and the inside of the second circumferential groove 14. Therefore, when viewed in the axial direction, the sealing material 55 can be arranged to span both the main body side wall surface 13d and the cover side wall surface 17d, so that the main body side wall portion 13 and the cover side wall portion 17 can be more appropriately sealed by the sealing material 55. Therefore, the sealing performance between the housing main body 11 and the cover member 16 can be further improved.

[0109] <Second embodiment>

[0110] Figure 8 1 is a cross-sectional view showing an electric actuator 101 according to the second embodiment. In the following description, the same reference numerals are given to the same components as those of the first embodiment, and the description thereof will be omitted.

[0111] like Figure 8 As shown, in the present embodiment, the second circumferential groove is not provided on the main body side wall surface 113d of the main body side wall portion 113. The main body side wall surface 113d extends linearly in the up-down direction (Z-axis direction). It should be noted that the first circumferential groove 18 of the present embodiment is provided on the surface of the main body side wall surface 113d and the cover side wall surface 17d that faces radially outward, i.e., the cover side wall surface 17d, similarly to the first embodiment described above.

[0112] The space portion 150 is composed of the first circumferential groove 18 and the main body side wall surface 113d. When viewed in the circumferential direction, the space portion 150 is a semicircular space that protrudes radially inward. Although the illustration is omitted, as in the first embodiment described above, the space portion 150 extends all around in a direction orthogonal to the axial direction. The space portion 150 is filled with a sealing material 155. The sealing material 155 is in contact with both the inner surface of the first circumferential groove 18 and the main body side wall surface 113d. Thus, the sealing material 155 seals between the main body side wall portion 113 and the cover side wall portion 17. That is, the sealing material 155 seals between the shell body 111 and the cover member 16. Other structures of the space portion 150 and the sealing material 155 of this embodiment are the same as other structures of the space portion 50 and the sealing material 55 of the first embodiment described above.

[0113] The connection hole 119 is provided on the main body side wall portion 113. The connection hole 119 is a hole that penetrates the main body side wall portion 113 in the radial direction. When viewed in the radial direction, the connection hole 119 overlaps with the first circumferential groove 18. Thus, the connection hole 119 connects the space portion 150 with the external space of the shell 110. In the present embodiment, the shell 110 has a plurality of connection holes 119. In the present embodiment, the shell 110 has two connection holes 119. The plurality of connection holes 119 include a first connection hole 119a and a second connection hole 119b. The first connection hole 119a is provided at the edge of the left side (-D2 side) of the main body side wall portion 113. The first connection hole 119a connects the space portion 150 with the external space of the shell 110. The second connection hole 119b is provided at the edge of the right side (+D2 side) of the main body side wall portion 113. The second connection hole 119b connects the space portion 150 with the external space of the shell 110. The other structures and the like of the connection hole 119 are the same as the structures and the like of the connection hole 19 of the above-mentioned first embodiment.

[0114] According to the present embodiment, the first circumferential groove 18 is provided on the surface of the main body side wall surface 113d and the cover side wall surface 17d that faces radially outward. Therefore, for example, when the first circumferential groove 18 is provided on the cover side wall surface 17d using a cutting machine, the first circumferential groove 18 can be provided from the radially outward of the cover side wall portion 17 using the cutting machine. Therefore, compared with the case where the first circumferential groove 18 is provided on the surface of the main body side wall surface 113d and the cover side wall surface 17d that faces radially inward, the first circumferential groove 18 can be provided more easily. Therefore, it is possible to suppress an increase in the manufacturing man-hours and manufacturing costs of the housing 10.

[0115] In addition, in the present embodiment, the sealing material 155 is filled in the space 150 formed by the first circumferential groove 18 recessed radially from the cover side wall surface 17d and the main body side wall surface 113d extending linearly in the up-down direction (Z-axis direction), so that the main body side wall portion 113 and the cover side wall portion 17 can be sealed. Therefore, compared with a structure in which a circumferential groove is also provided on the main body side wall portion 113, it is easy to reduce the radial thickness of the main body side wall portion 113. Therefore, the miniaturization of the electric actuator 101 can be more appropriately achieved.

[0116] The embodiments of the present invention are described above, but the various structures and their combinations in the embodiments are examples, and addition, omission, substitution and other changes of structures can be made without departing from the scope of the purpose of the present invention. In addition, the present invention is not limited to the embodiments.

[0117] The space portion can be composed of a second circumferential groove that is recessed radially inward from the main body side wall surface and a cover side wall surface that extends linearly along the axial direction. In addition, the length of the first space portion and the length of the second space portion can be different lengths, and the first space portion and the second space portion can also be asymmetrical shapes relative to the first imaginary line. In these structures, in the third step of the cover component fixing process, after the operator confirms that the liquid sealing material has leaked from the second connecting hole, after continuing to fill the liquid sealing material for a predetermined time, the operator stops filling the liquid sealing material, etc., thereby filling the liquid sealing material all around the space portion.

[0118] The positions of the first connection hole and the second connection hole are not limited to the present embodiment. For example, the first connection hole may be provided at the right side of the main body side wall portion, and the second connection portion may be provided at the left side of the main body side wall portion. In addition, the first connection hole and the second connection hole may not be provided at positions sandwiching the motor axis in the radial direction. The interior of the connection hole may not be filled with adhesive.

[0119] The shapes of the main body side wall surface and the cover side wall surface are not limited to the present embodiment. For example, when viewed in the axial direction, the main body side wall surface and the cover side wall surface may be rectangular or circular. In addition, the main body side wall surface and the cover side wall surface may not have corners. In this case, in the third step of the cover component fixing process, the pressure loss of the liquid sealing material flowing in the space portion can be reduced, so that the liquid sealing material can be more easily filled into the interior of the space portion.

[0120] The structure of the transmission mechanism is not particularly limited as long as it can reduce the rotation of the motor shaft and transmit it to the output shaft. For example, the motor shaft and the motor gear may be part of the same single component, or the output shaft and the output gear may be part of the same single component.

[0121] The application of the electric actuator of the utility model is not particularly limited. The electric actuator can be installed on an actuator device of a wire-controlled shift system driven based on the driver's shift operation. In addition, the electric actuator can also be mounted on equipment other than the vehicle. It should be noted that the above-mentioned structures described in this specification can be appropriately combined within the scope of non-contradiction.

[0122] It should be noted that the present technology can adopt the following structures.

[0123] (1) An electric actuator comprising: a motor having: a rotor having a motor shaft rotatable about a motor axis; and a stator disposed radially outside the rotor; a transmission mechanism that decelerates the rotation of the motor shaft and transmits it to an output shaft; and a housing that accommodates the motor and the transmission mechanism, the housing having: a cylindrical housing body having an opening portion opening to one axial side and a body side wall portion extending in the axial direction; and a cover member having a cover side wall portion extending in the axial direction and covering the opening portion, wherein a surface of the body side wall portion facing the radial side, i.e., a body side wall surface, and the The surface of the cover side wall portion facing the other radial side, namely the cover side wall surface, is radially opposed, and a first circumferential groove is provided on one of the main body side wall surface and the cover side wall surface. The first circumferential groove is radially recessed relative to the other of the main body side wall surface and the cover side wall surface, and extends all around in a direction orthogonal to the axial direction. The shell has a connecting hole, which connects a space portion formed by the first circumferential groove and the other of the main body side wall surface and the cover side wall surface with an external space of the shell. In the space portion, a sealing material is filled all around to seal the main body side wall portion and the cover side wall portion.

[0124] (2) An electric actuator according to (1), wherein, when viewed in the axial direction, the main body side wall surface has a main body corner portion that is bent into an angle, and when viewed in the axial direction, the cover side wall surface is bent into an angle and has a cover corner portion that is radially opposite to the main body corner portion.

[0125] (3) The electric actuator according to (1) or (2), wherein a plurality of the connection holes are arranged at intervals along a direction in which the space portion extends when viewed in the axial direction.

[0126] (4) The electric actuator according to (3), wherein two of the plurality of connection holes are arranged at positions sandwiching the motor axis in a radial direction.

[0127] (5) An electric actuator according to (3) or (4), wherein the space portion comprises: a first space portion, which passes through a side of a first direction orthogonal to the axial direction that is closer to the motor axis; and a second space portion, which passes through a side of the first direction that is closer to the motor axis, wherein the plurality of connecting holes include a first connecting hole and a second connecting hole, the first space portion and the second space portion respectively connect the first connecting hole and the second connecting hole, and the length of the first space portion is the same as the length of the second space portion.

[0128] (6) The electric actuator according to (5), wherein the first space portion and the second space portion are symmetrical to each other with a straight line passing through the first connection hole and the second connection hole as a symmetry line when viewed in the axial direction.

[0129] (7) The electric actuator according to any one of (1) to (6), wherein the first circumferential groove is provided on a surface facing radially outward among the body side wall surface and the cover side wall surface.

[0130] (8) The electric actuator according to any one of (1) to (7), wherein a sealing material is filled inside the connection hole.

[0131] (9) An electric actuator according to any one of (1) to (8), wherein a second circumferential groove is provided on the other of the main body side wall surface and the cover side wall surface, the second circumferential groove is radially recessed, extends all around in a direction orthogonal to the axial direction, and is radially opposite to the first circumferential groove, the space portion is composed of the first circumferential groove and the second circumferential groove, and the sealing material is filled in a manner spanning the interior of the first circumferential groove and the interior of the second circumferential groove.

Claims

1. An electric actuator, characterized in that: have: A motor having: a rotor having a motor shaft rotatable about a motor axis; and a stator disposed radially outside the rotor; a transmission mechanism that reduces the speed of rotation of the motor shaft and transmits the speed to an output shaft; and a housing for housing the motor and the transmission mechanism, The housing has: A cylindrical housing body having an opening portion opened to one side in the axial direction and a body side wall portion extending in the axial direction; and a cover member having a cover side wall portion extending in the axial direction and covering the opening portion, The main body side wall surface, which is a surface of the main body side wall portion facing one side in the radial direction, and the cover side wall surface, which is a surface of the cover side wall portion facing the other side in the radial direction, are opposed to each other in the radial direction. A first circumferential groove is provided on one of the main body side wall surface and the cover side wall surface. The first circumferential groove is recessed in the radial direction relative to the other of the main body side wall surface and the cover side wall surface and extends all around in a direction orthogonal to the axial direction. The housing has a connection hole that connects a space formed by the first peripheral groove and the other of the main body side wall surface and the cover side wall surface to an external space of the housing. The space portion is filled all around with a sealing material that seals between the main body side wall portion and the cover side wall portion.

2. The electric actuator according to claim 1, characterized in that: When viewed in the axial direction, the side wall of the main body has a main body corner portion that is bent into an angle. When viewed in the axial direction, the cover side wall surface is curved into an angle shape and has a cover corner portion radially opposite to the main body corner portion.

3. The electric actuator according to claim 1, characterized in that: When viewed in the axial direction, a plurality of the connection holes are arranged at intervals along a direction in which the space portion extends.

4. The electric actuator according to claim 3, characterized in that: Two of the plurality of connection holes are arranged at positions sandwiching the motor axis in the radial direction.

5. The electric actuator according to claim 3, characterized in that: The space portion includes: a first space portion passing through one side of the motor axis in a first direction orthogonal to the axial direction; and a second space portion passing through the other side of the motor axis in the first direction. The plurality of connection holes include a first connection hole and a second connection hole, The first space portion and the second space portion are connected to the first connection hole and the second connection hole respectively. The length of the first space portion is the same as the length of the second space portion.

6. The electric actuator according to claim 5, characterized in that: When viewed in the axial direction, the first space portion and the second space portion are in line-symmetric shapes with respect to a straight line passing through the first connection hole and the second connection hole.

7. The electric actuator according to claim 1, characterized in that: The first circumferential groove is provided on a surface facing radially outward among the main body side wall surface and the cover side wall surface.

8. The electric actuator according to claim 1, characterized in that: The connection hole is filled with a sealing material.

9. The electric actuator according to any one of claims 1 to 8, characterized in that: A second circumferential groove is provided on the other of the main body side wall surface and the cover side wall surface. The second circumferential groove is recessed in the radial direction, extends all around in a direction perpendicular to the axial direction, and faces the first circumferential groove in the radial direction. The space portion is formed by the first circumferential groove and the second circumferential groove, The sealing material is filled so as to span the inside of the first peripheral groove and the inside of the second peripheral groove.

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