Electric drive

Abstract

The utility model provides an electric driver. The electric driver comprises: a motor having a rotor with a motor shaft and a stator; a transmission mechanism that transmits rotation of the motor shaft to the output shaft; a stator cover disposed on one axial side of the stator and in contact with the stator in the axial direction; and a housing. The housing main body includes: a first positioning portion that supports the stator from the other side in the axial direction; and a second positioning portion determining a radial position of the stator. A radially outward surface of the stator cover is in contact with a radially inward surface of the housing main body in the radial direction. The surface of the housing body facing the radial inner side is provided with a first circumferential groove which is recessed towards the radial outer side and extends in the circumferential direction. The surface of the stator cover facing the radial outer side is provided with a second circumferential groove which is recessed toward the radial inner side, extends in the circumferential direction, and faces the first circumferential groove in the radial direction. A space formed by the first peripheral groove and the second peripheral groove is filled with an adhesive that spans the inside of the first peripheral groove and the inside of the second peripheral groove.

Description

Technical Field

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

[0002] There is known an electric actuator having a structure in which a stator is fixed to a case that accommodates a motor (for example, Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-68520 Utility Model Content

[0006] Issues to be Solved by Utility Models

[0007] In the electric actuator as described above, in a structure where the stator is pressed and fixed to the housing, if the interference between the housing and the stator is large, the press-in load applied to the housing increases, so the housing may crack. In addition, if the interference between the housing and the stator is small, the press-in load decreases due to the thermal contraction of the housing and the stator accompanying the temperature change of the electric actuator, and the stator may not be firmly fixed to the housing. Therefore, in order to reduce the press-in load applied to the housing while firmly fixing the stator to the housing, it is necessary to improve the dimensional accuracy of the housing and the stator, but in this case, the manufacturing cost of the housing and the stator increases, so the manufacturing cost of the electric actuator increases.

[0008] In view of the above situation, one of the purposes of the present invention is to provide an electric drive capable of suppressing an increase in manufacturing cost.

[0009] Solutions to Solve Problems

[0010] Scheme 1 of the present invention is an electric drive, characterized in that it comprises: a motor having a rotor with a motor shaft rotatable around a motor axis and a stator arranged on the radially outer side of the rotor; a transmission mechanism for reducing the rotation of the motor shaft and transmitting it to an output shaft; a stator cover arranged on one axial side of the stator and in axial contact with the stator; and a housing in which the motor, the transmission mechanism and the stator cover are respectively accommodated, the housing comprising: a cylindrical housing body having an opening portion opened on one axial side; and a cover member covering the opening portion, the housing body comprising: a cover member extending from the other axial side A first positioning portion supporting the above-mentioned stator; and a second positioning portion determining the radial position of the above-mentioned stator relative to the above-mentioned housing body, the radially outward surface of the above-mentioned stator cover is in radial contact with the radially inward surface of the above-mentioned housing body, and the radially inward surface of the above-mentioned housing body is provided with a first circumferential groove which is recessed radially outward and extends circumferentially, and the radially outward surface of the above-mentioned stator cover is provided with a second circumferential groove which is recessed radially inward, extends circumferentially and is radially opposite to the above-mentioned first circumferential groove, and the space formed by the above-mentioned first circumferential groove and the above-mentioned second circumferential groove is filled with an adhesive which spans the interior of the above-mentioned first circumferential groove and the interior of the above-mentioned second circumferential groove.

[0011] Solution 2 is the electric actuator according to Solution 1, characterized in that the first circumferential groove and the second circumferential groove each extend throughout the circumference in the circumferential direction.

[0012] Solution 3 is the electric actuator according to Solution 1, characterized in that at least one of the stator cover and the housing body has a connection portion that connects the space portion and a space inside the housing.

[0013] A fourth aspect is the electric actuator according to the third aspect, wherein a plurality of the connection portions are arranged at intervals in the circumferential direction.

[0014] A fifth aspect is the electric actuator according to the fourth aspect, wherein two of the plurality of connection portions are arranged at positions sandwiching the motor axis in a radial direction.

[0015] Aspect 6 is the electric actuator according to any one of aspects 3 to 5, characterized in that an adhesive is filled inside the connecting portion.

[0016] A seventh aspect is the electric actuator according to any one of the third to fifth aspects, wherein the connection portion is a hole provided in the stator cover and extending from the space portion to one side in the axial direction.

[0017] Aspect 8 is the electric actuator according to any one of aspects 1 to 5, characterized in that the housing body and the stator cover are each made of resin.

[0018] Utility Model Effect

[0019] According to one aspect of the present invention, in the electric actuator, it is possible to suppress an increase in manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a perspective view showing the electric actuator according to the first embodiment.

[0021] Figure 2 It is a cross-sectional view showing the electric actuator according to the first embodiment.

[0022] Figure 3 is a cross-sectional view showing the electric actuator according to the first embodiment, and is Figure 2 III-III sectional view.

[0023] Figure 4 It is a plan view showing a part of the electric actuator according to the first embodiment.

[0024] Figure 5 This is an enlarged cross-sectional view showing a part of the electric actuator according to the first embodiment.

[0025] Figure 6 It is an enlarged cross-sectional view showing another part of the electric actuator according to the first embodiment.

[0026] Figure 7 This is a first cross-sectional view showing the stator fixing step of the first embodiment.

[0027] Figure 8 This is a second cross-sectional view showing the stator fixing step of the first embodiment.

[0028] Fig. 9 It is a first cross-sectional view showing the electric actuator according to the second embodiment.

[0029] Fig.10 It is a second cross-sectional view showing the electric actuator according to the second embodiment.

[0030] In the figure:

[0031] 1. 101—electric driver, 9—motor, 10. 110—housing, 11. 111—housing body, 12b—opening, 12c—first positioning portion, 12e—second positioning portion, 12g—first circumferential groove, 16—cover component, 20—rotor, 23—motor shaft, 30—stator, 40. 140—stator cover, 42a—second circumferential groove, 43. 118—connecting portion, 50—space portion, 55—adhesive, 60—transmission mechanism, 66—output shaft, J1—motor axis. DETAILED DESCRIPTION

[0032] In each figure, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the Z-axis direction is the up-down direction with the positive side (+Z side) being the upper side and the negative side (-Z side) being the lower side. The X-axis direction is orthogonal to the Z-axis direction, and is the left-right direction with the positive side (+X side) being the right side and the negative side (-X side) being the left side. The Y-axis direction is orthogonal to both the X-axis direction and the Z-axis direction, and is the front-back direction with the positive side (+Y side) being the front side and the negative side (-Y side) being the rear side. In addition, the left side, right side, front side, rear side, upper side, and lower side are merely names used to illustrate the relative positional relationship of each part, and the actual configuration relationship, etc. may also be a configuration relationship, etc. other than the configuration relationship, etc. indicated by these names, etc.

[0033] 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". In this embodiment, the upper side (+Z side) corresponds to one side of the axial direction, and the lower side (-Z side) corresponds to the other side of the axial direction.

[0034] In each figure, the circumferential direction is indicated by an arrow θ1. The side in the circumferential direction to which the arrow θ1 points is referred to as "one circumferential side". The side opposite to the side in the circumferential direction to which the arrow θ1 points is referred to as "the other circumferential side". One circumferential side is the side that moves clockwise around the motor axis J1 when viewed from the top. The other circumferential side is the side that moves counterclockwise around the motor axis J1 when viewed from the axial side.

[0035] <First embodiment>

[0036] Figure 1 The electric actuator 1 of the present embodiment shown is mounted on a vehicle. More specifically, the electric actuator 1 is mounted on a drive device of a park-by-wire method that is driven based on a shift operation of a vehicle driver, for example. 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 .

[0037] 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 and a cover member 16. The housing body 11 is cylindrical and surrounds the motor axis J1. The housing body 11 has an opening portion 12b that is open on the upper side, i.e., on one side in the axial direction. The housing body 11 has a first storage portion 12, a second storage portion 14 and a connector portion 15. The second storage portion 14 is arranged on the upper side of the first storage portion 12. The first storage portion 12 and the second storage portion 14 are connected 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.

[0038] The first housing portion 12 is a lower portion of the housing body 11. The first housing portion 12 includes a cylindrical first peripheral wall portion 12a extending in the axial direction and a bottom wall portion 13 extending radially inward from a lower end of the first peripheral wall portion 12a.

[0039] The bottom wall portion 13 is provided with a hole portion 13a and a bearing holding portion 13b. The hole portion 13a is a hole that penetrates the bottom wall portion 13 in the axial direction. When viewed in the axial direction, the hole portion 13a is a circular shape centered on the motor axis J1. A filter component 95 is detachably mounted on the hole portion 13a. The filter component 95 is a filter that can ventilate the inside of the housing 10 and the outside of the housing 10. An O-ring 96 is arranged between the filter component 95 and the inner side surface of the hole portion 13a. The O-ring 96 seals the filter component 95 and the housing 10.

[0040] The bearing holding portion 13b protrudes upward from the bottom wall portion 13. The bearing holding portion 13b is cylindrical centered on the motor axis J1. The first bearing 91 is held on the inner peripheral surface of the bearing holding portion 13b. In the present embodiment, the first bearing 91 is a ball bearing.

[0041] The first circumferential wall portion 12a is cylindrical and surrounds the motor axis J1. The first circumferential wall portion 12a surrounds the lower portion of the motor 9 and the stator cover 40 from the radial outside. When viewed in the axial direction, the inner circumferential surface of the first circumferential wall portion 12a is a circle centered on the motor axis J1. The first circumferential wall portion 12a has a first positioning portion 12c, a first step surface 12d, a second positioning portion 12e, a first circumferential groove 12g, and a housing protrusion 12h.

[0042] The first positioning portion 12c is a stepped surface facing upward. The first positioning portion 12c is a portion of the inner surface of the first peripheral wall portion 12a. When viewed in the axial direction, the first positioning portion 12c is annular in shape with the motor axis J1 as the center. The first step surface 12d is a stepped surface facing upward. The first step surface 12d is a portion of the inner surface of the first peripheral wall portion 12a. When viewed in the axial direction, the first step surface 12d is annular in shape with the motor axis J1 as the center. The first step surface 12d is arranged on the upper side 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.

[0043] The second positioning portion 12e is cylindrical and surrounds the motor axis J1 and extends 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 stepped surface 12d in the first circumferential wall portion 12a. 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 stepped surface 12d.

[0044] The first circumferential groove 12g is a groove recessed radially outward from the inner circumferential surface of the first circumferential wall portion 12a. That is, the first circumferential groove 12g is provided on the surface of the housing body 11 facing radially inward. The first circumferential groove 12g is arranged above the first step surface 12d. Figure 3 As shown, the first circumferential groove 12g extends in the circumferential direction. The first circumferential groove 12g extends all around the circumferential direction. Figure 2 As shown, when viewed in the circumferential direction, the first circumferential groove 12g is a semicircular shape convex to the radial outside. When viewed in the circumferential direction, the first circumferential groove 12g may also be a rectangular or triangular shape. The first circumferential groove 12g is filled with an adhesive 55.

[0045] The housing protrusion 12h is a cylindrical shape that protrudes upward from the edge of the right side (+X side) of the upper surface of the first housing portion 12. An internal threaded hole that is recessed downward is provided on the upper surface of the housing protrusion 12h. Figure 4 As shown in FIG. 1 , in this embodiment, two housing protrusions 12h are provided. The housing protrusions 12h are arranged at intervals in the front-rear direction (Y-axis direction).

[0046] like Figure 2 As shown, the second housing portion 14 is the upper portion of the housing body 11. The second housing portion 14 is cylindrical and surrounds the motor axis J1 and protrudes in the axial direction. The second housing portion 14 surrounds the circuit substrate 80 from the radially outer side. Figure 1As shown in FIG. 1 , when viewed along the axial direction, the left side (-X side) of the second housing portion 14 is a roughly semicircular arc centered on the motor axis J1. When viewed along the axial direction, the right side (+X side) of the second housing portion 14 is a roughly rectangular shape with the long side extending in the front-to-back direction (Y-axis direction). Figure 2 As shown, the right side portion of the inner side surface of the second housing portion 14 is located to the right of the inner peripheral surface of the first housing portion 12 .

[0047] The connector portion 15 is cylindrical and protrudes to the right (+X side) from the first housing portion 12. The connector portion 15 holds a plurality of connector pins 15a. The right ends of the plurality of connector pins 15a are located inside the connector portion 15. The plurality of connector pins 15a are electrically connected to the circuit board 80.

[0048] 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 receiving portion 16a and a flange portion 16d. The cover receiving portion 16a is box-shaped and protrudes in the axial direction. The cover receiving portion 16a is open at the lower side. The interior of the cover receiving 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 receiving portion 16a. Figure 1 As shown, when viewed in the axial direction, the left side (-X side) of the cover storage portion 16a is a roughly semicircular shape centered on the motor axis J1. When viewed in the axial direction, the right side (+X side) of the cover storage portion 16a is a roughly rectangular shape with the long side extending in the front-to-back direction (Y-axis direction). The cover storage portion 16a is provided with a cover hole portion 16b.

[0049] 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 (+X 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 figure.

[0050] The flange portion 16d is a plate-shaped portion 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 second receiving portion 14. The outer edge of the flange portion 16d is fixed to the second receiving portion 14. Thus, the cover member 16 is fixed to the housing body 11. In addition, the cover member 16 and the housing body 11 may be fixed by bolts, etc., which are not shown, or may be fixed by heat welding.

[0051] like Figure 2As shown, the motor 9 has a rotor 20 and a stator 30. The rotor 20 can rotate 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 on the motor axis J1. The rotor core 21 is housed inside the first housing portion 12. The magnet is fixed to the rotor core 21. In this embodiment, a plurality of magnets are arranged at intervals in the circumferential direction.

[0052] The motor shaft 23 is rotatable about the motor axis J1. The motor shaft 23 is substantially cylindrical and extends axially about the motor axis J1. The motor shaft 23 extends across the interior of the first housing portion 12, the interior of the second housing portion 14, and the interior of the cover housing portion 16a. The rotor core 21 is fixed to the outer peripheral surface of the motor shaft 23. The lower end of the motor shaft 23 is located below the rotor core 21. The motor shaft 23 is supported by the first bearing 91 and the second bearing 92 so as to be rotatable about the motor axis J1.

[0053] The stator 30 surrounds the rotor 20 from the radially outer side. The stator 30 is arranged radially outside the rotor 20. The stator 30 and the rotor 20 are arranged to face each other with a gap therebetween in the radial direction. The stator 30 is accommodated inside the first accommodation portion 12. The stator 30 has a stator core 31, an insulator 32, and a coil portion 35.

[0054] The stator core 31 is annular and surrounds the rotor core 21 from the outside in the radial direction. The stator core 31 and the rotor 20 are opposed to each other with a gap therebetween in the radial direction. Figure 3 As shown in FIG. 1 , the stator core 31 includes a core back 31 a and a plurality of teeth 31 b. The core back 31 a is annular centered on the motor axis J1. Figure 2 As shown, the core back portion 31a is loosely fitted in the second positioning portion 12e of the housing body 11. As a result, the radial position of the stator 30 relative to the housing body 11 is determined. That is, the radial position of the stator 30 relative to the housing body 11 is determined by the second positioning portion 12e. The surface of the core back portion 31a facing downward, that is, the first support surface 31d, is in axial contact with the first positioning portion 12c. As a result, the housing body 11 supports the stator 30 from the bottom, that is, the other axial side. Therefore, the axial position of the stator 30 relative to the housing body 11 is determined.

[0055] like Figure 3 As shown, a plurality of teeth 31b protrude radially inward from the core back portion 31a. In this embodiment, the stator core 31 has six teeth 31b. The teeth 31b are arranged at intervals along the circumferential direction. The insulator 32 is mounted on the stator core 31. The insulator 32 insulates the stator core 31 and the coil portion 35.

[0056] like Figure 2As shown, the coil portion 35 has a plurality of coil main bodies 35a and coil lead wires 35b. The plurality of coil main bodies 35a are respectively mounted on the teeth 31b via the insulator 32. The coil lead wires 35b are led out from the coil main bodies 35a to the upper side and connected to the circuit substrate 80. Thus, the coil portion 35 is electrically connected to the circuit substrate 80. Figure 4 As shown in FIG. 1 , in the present embodiment, the coil portion 35 has six coil lead wires 35 b. In addition, the coil portion 35 and the circuit board 80 may be electrically connected via a conductive member such as a bus bar.

[0057] 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 on the upper side of the stator 30. The circuit substrate 80 is accommodated in the second accommodating portion 14. The coil lead wire 35b is connected to the circuit substrate 80. 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.

[0058] When viewed in the axial direction, the first substrate hole 80a is a roughly 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 a roughly circular shape. 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 (-X side) of the circuit substrate 80. Although not shown in the figure, the other two second substrate holes 80b are arranged in the front-to-back direction (Y-axis direction) with the motor axis J1 sandwiched therebetween.

[0059] 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. In the present embodiment, two third substrate holes 80c are provided in the circuit substrate 80. Each third substrate hole 80c is arranged at intervals in the front-to-back direction (Y-axis direction). The periphery of each third substrate hole 80c is supported from the lower side 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 is passed axially through each third substrate hole 80c and 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.

[0060] The transmission mechanism 60 is arranged on the upper side of the circuit substrate 80. The transmission mechanism 60 is housed inside the cover housing 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 motor shaft 23 and transmits it to the output shaft 66. The transmission mechanism 60 may also increase the speed of the rotation of the motor shaft 23 and transmit it to the output shaft 66, or may transmit the rotation of the same speed as the rotation of the motor shaft 23 to the output shaft 66. The transmission mechanism 60 includes 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 sequentially 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.

[0061] 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.

[0062] 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.

[0063] The first large diameter gear 62a is in the shape of an annular plate with the output axis J2 as the center. 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 radially 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. As a result, the rotation of the motor shaft 23 and the motor gear 61 is reduced in speed and transmitted to the first-stage gear 62. The first small diameter gear 62b is in the shape of an annular plate with the output axis J2 as the center. 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 radially outer side of the output.

[0064] 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 an annular plate centered on the motor axis J1. The motor shaft 23 passes through the inside 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 includes 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.

[0065] 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 larger than the number of teeth of the first small diameter gear portion. As a result, the rotation of the first stage gear 62 is transmitted to the second stage gear 63 at a reduced speed. 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.

[0066] The output gear 64 transmits the rotation of the second-stage gear 63 to the output shaft 66. The output gear 64 is 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.

[0067] The output shaft 66 outputs the driving force of the electric actuator 1. The output shaft 66 is 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.

[0068] 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 first housing portion 12. The stator cover 40 is surrounded by the first peripheral wall portion 12a from the radially outer side. The stator cover 40 is arranged on the upper side of the stator 30, that is, on one side in the axial direction. 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.

[0069] The cover body 41 is in the shape of a plate extending in a direction perpendicular to the axial direction. Figure 4 As shown in FIG. 1 , in this embodiment, the cover body 41 is an annular plate centered on the motor axis J1. The cover body 41 includes a first cover hole 41b, a second cover hole 41f, a third cover hole 41h, and a protruding portion 41i. The first cover hole 41b, the second cover hole 41f, and the third cover hole 41h are holes that penetrate the cover body 41. Figure 2 As shown, the cover body 41 has a cover recess 41e.

[0070] When viewed in the axial direction, the first cover hole portion 41b is 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. Figure 4 As shown, when viewed in the axial direction, the second cover hole portion 41f is circular. In this embodiment, the cover body portion 41 has three second cover holes 41f. The three second cover holes 41f are arranged at approximately equal intervals in the circumferential direction. Two coil lead wires 35b are passed through each second cover hole portion 41f in the axial direction. When viewed in the axial direction, the third cover hole portion 41h is circular centered on the output axis J2. As shown in FIG. Figure 2As shown, 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 as to be rotatable around the output axis J2. In this embodiment, the third bearing 93 is a sliding bearing. The third bearing 93 can also be a ball bearing.

[0071] 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.

[0072] The protrusion 41i is a cylindrical shape that protrudes upward from the cover body 41. Figure 4 As shown, in the present embodiment, the cover body 41 has three protrusions 41i. One protrusion 41i is connected to the edge of the left side (-X side) of the cover body 41. The other two protrusions 41i are arranged in the front-to-back direction (Y-axis direction) with the motor axis J1 sandwiched therebetween. The other two protrusions 41i are connected to the edges of the cover body 41 in the front-to-back direction. An internal threaded hole that is recessed downward from the surface of each protrusion 41i facing upward is provided on each protrusion 41i. As shown in FIG. Figure 2 As shown, each protrusion 41i supports the peripheral edge 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. In addition, when the screw 98 passes through each second substrate hole 80b in the axial direction and is screwed into the internal thread 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.

[0073] 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 upper portion of the inner circumferential surface of the cover fixing portion 42 is connected to the radial outer edge of the cover main body 41. The lower end of the cover fixing portion 42 is located below the lower end of the cover main body 41. The surface of the cover fixing portion 42 facing downward is in axial contact with the surface of the core back portion 31a of the stator core 31 facing upward, that is, the second support surface 31e. Thus, the stator cover 40 supports the stator 30 from the upper side. Therefore, the axial position of the stator 30 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 stator core 31 relative to the housing body 11 is determined via the stator cover 40. The outer circumferential surface of the cover fixing portion 42 is in radial contact with the inner circumferential surface of the housing body 11. That is, the surface of the stator cover 40 facing radially outward is in radial contact with the surface of the housing body 11 facing radially inward. In the present embodiment, the cover fixing portion 42 is loosely fitted in the housing body 11. Thus, the radial position of the stator cover 40 relative to the housing body 11 is determined. In addition, the lower end of the cover fixing portion 42 may be in axial contact with the first step surface 12d of the housing body 11, or may not be in contact with the first step surface 12d. The cover fixing portion 42 has a second circumferential groove 42a and a connecting portion 43. That is, in the present embodiment, the stator cover 40 has a connecting portion 43.

[0074] The second circumferential groove 42a is a groove recessed radially inward from the outer circumferential surface of the cover fixing portion 42. That is, the second circumferential groove 42a is provided on the surface of the stator cover 40 that faces radially outward. Figure 3 As shown, the second circumferential groove 42a extends in the circumferential direction. The second circumferential groove 42a extends all around the circumferential direction. Figure 2 As shown, when viewed in the circumferential direction, the second circumferential groove 42a is a semicircular shape convex radially inward. When viewed in the circumferential direction, the second circumferential groove 42a may also be other shapes such as a rectangle and a triangle. The second circumferential groove 42a is radially opposed to the first circumferential groove 12g. Thus, the interior of the second circumferential groove 42a and the interior of the first circumferential groove 12g are radially connected. The internal space of the first circumferential groove 12g and the internal space of the second circumferential groove 42a constitute a space portion 50. That is, the space portion 50 is composed of the first circumferential groove 12g and the second circumferential groove 42a. When viewed in the circumferential direction, the space portion 50 is a circular space. As shown in FIG. Figure 3 As shown in FIG. 1 , the space portion 50 is formed all around the circumference. Figure 2 As shown, the second peripheral groove 42a is filled with adhesive 55. As described above, the first peripheral groove 12g is filled with adhesive 55. That is, the space 50 is filled with adhesive 55 that spans the first peripheral groove 12g and the second peripheral groove 42a. Thus, the stator cover 40 is fixed to the housing body 11. Figure 3As shown, the adhesive 55 is filled in the space 50 all around the circumference.

[0075] In the present embodiment, for example, a thermosetting adhesive such as an epoxy resin adhesive, a melamine resin adhesive, or a phenol resin adhesive can be used as the adhesive 55. In the present embodiment, the adhesive 55 is an epoxy resin adhesive.

[0076] like Figure 2 As shown, in this embodiment, the connection portion 43 is a hole extending downward from the upper surface of the cover fixing portion 42. The connection portion 43 is connected to the second peripheral groove 42a. The connection portion 43 is a hole extending upward from the space portion 50, that is, one side of the axial direction. Thus, the connection portion 43 connects the space portion 50 and the space inside the housing 10. Figure 3 As shown, when viewed along the axial direction, the connection portion 43 is circular. When viewed along the axial direction, the connection portion 43 may also be other shapes such as a rectangle and a triangle. In this embodiment, the cover fixing portion 42 has a plurality of connection portions 43. In this embodiment, the cover fixing portion 42 has two connection portions 43. The connection portion 43 includes a first connection portion 43a and a second connection portion 43b. In addition, the cover fixing portion 42 may also have more than three connection portions 43.

[0077] The first connection portion 43a is provided at the edge of the left side (-X side) of the cover fixing portion 42. Figure 5 As shown, the first connection portion 43a connects the space portion 50 and the space inside the housing 10. Figure 4 As shown in FIG. 1 , the second connection portion 43b is provided at the edge of the right side (+X side) of the cover fixing portion 42. That is, a plurality of connection portions 43 are arranged at intervals from each other in the circumferential direction. Figure 6 As shown, the second connection portion 43b connects the space portion 50 and the space inside the housing 10. Figure 4 As shown in FIG. 1 , the two connection portions 43a and 43b are arranged at positions sandwiching the motor axis J1 in the radial direction. Figure 3 As shown, the space portion 50 has a first space portion 50a and a second space portion 50b. The first space portion 50a extends from the first connection portion 43a toward the other side (-θ1 side) in the circumferential direction. The first space portion 50a connects the first connection portion 43a and the second connection portion 43b. The second space portion 50b extends from the first connection portion 43a toward one side (+θ1 side) in the circumferential direction. The second space portion 50b connects the first connection portion 43a and the second connection portion 43b. As described above, the two connection portions 43a and 43b are arranged at positions that sandwich the motor axis J1 in the radial direction, so the circumferential length of the first space portion 50a is the same length as the circumferential length of the second space portion 50b. In addition, as described above, Figure 5 As shown in FIG. 4 , the first connecting portion 43a is filled with an adhesive 55. Figure 6 As shown, the second connection portion 43 b is filled with the adhesive 55 . That is, the connection portion 43 is filled with the adhesive 55 .

[0078] Next, the stator fixing process Ms of the electric drive 1 of the present embodiment is described. The stator fixing process Ms is a part of the manufacturing process of the electric drive 1. In the stator fixing process Ms, the stator 30 and the stator cover 40 are fixed to the housing body 11. The stator fixing process Ms includes a first step S1 of installing various parts of the motor 9 on the housing body 11, a second step S2 of installing the stator cover 40 on the housing body 11, and a third step S3 of filling the space portion 50 with an adhesive 55. In addition, in this specification, "operators, etc." include operators and assembly devices, etc. who perform various operations of the stator fixing process Ms. Each operation may be performed only by an operator, only by an assembly device, or by an operator and an assembly device.

[0079] In the first step S1, Figure 7 As shown, the operator etc. installs the various parts of the motor 9 such as the rotor 20 and the stator 30 and the first bearing 91 to the housing body 11 fixed by a clamp etc. not shown in the figure. The various parts of the motor 9 are installed inside the housing body 11 through the opening portion 12b. At this time, the outer peripheral surface of the stator core 31 is gap-fitted into the second positioning portion 12e of the housing body 11. Thus, the radial position of the stator 30 relative to the housing body 11 is determined. In addition, the first support surface 31d of the stator core 31 is in contact with the first positioning portion 12c in the axial direction. Thus, the stator 30 is supported by the housing body 11 from the bottom side. When the various parts of the motor 9 are installed in the housing body 11, the first step S1 is completed.

[0080] In the second step S2, the operator moves the stator cover 40 with the second bearing 92 installed from the upper side to the lower side of the housing body 11 and inserts it into the housing body 11 through the opening 12b. At this time, the motor shaft 23 and the coil lead wire 35b pass through the first cover hole 41b and the second cover hole 41f in the axial direction, respectively. Figure 8 As shown, when the operator moves the stator cover 40 downward until the surface of the cover fixing portion 42 facing downward contacts the second supporting surface 31e of the stator core 31 in the axial direction, the movement of the stator cover 40 is stopped. At this time, the first circumferential groove 12g and the second circumferential groove 42a are opposite to each other in the radial direction. Thus, the space portion 50 is formed by the first circumferential groove 12g and the second circumferential groove 42a. In addition, the outer peripheral surface of the cover fixing portion 42 is gap-fitted into the first circumferential wall portion 12a. Thus, the stator cover 40 is mounted on the housing body 11. When the stator cover 40 is mounted on the housing body 11, the second step S2 ends.

[0081] In the third step S3, first, the operator inserts a filling jig (not shown) into the housing body 11 through the opening 12b, and inserts the nozzle of the filling jig into the first connection portion 43a. Next, the operator fills the space portion 50 with a liquid adhesive 55 (not shown) from the first connection portion 43a using the filling jig. The liquid adhesive 55 that flows from the first connection portion 43a into the space portion 50 is Figure 3 As shown, the liquid adhesive 55 flows toward the second connection portion 43b in the first space portion 50a and the second space portion 50b, respectively. Then, the liquid adhesive 55 flowing in the first space portion 50a and the second space portion 50b, respectively, reaches the second connection portion 43b, and leaks out to the upper surface of the cover fixing portion 42 through the second connection portion 43b. When the operator or the like confirms that the liquid adhesive 55 leaks out to the upper surface of the cover fixing portion 42, the filling of the liquid adhesive 55 is completed. Then, when the operator or the like solidifies the liquid adhesive 55, the stator cover 40 is fixed to the housing body 11. As described above, the lower surface of the cover fixing portion 42 is in contact with the second support surface 31e of the stator core 31 in the axial direction. As a result, the stator 30 is supported from the upper side by the housing body 11 via the stator cover 40. In addition, as described above, the first support surface 31d of the stator core 31 is in contact with the first positioning portion 12c in the axial direction, so the stator 30 is supported from the lower side by the housing body 11. As a result, the axial position of the stator core 31 relative to the housing body 11 is determined. When the stator cover 40 is fixed to the housing body 11, the third step S3 is completed. When the third step S3 is completed, the stator fixing step Ms is completed.

[0082] According to the present embodiment, the connection portion 43 is a hole provided in the stator cover 40 and extending from the space portion 50 to the upper side, that is, to one side in the axial direction. Thus, in the third step S3 of the stator fixing process Ms, the nozzle of the filling jig can be easily inserted into the interior of the first connection portion 43a through the opening 12b. Therefore, in the third step S3, the workability of the operation of filling the space portion 50 with the liquid adhesive 55 can be improved. Therefore, the increase in the working hours of the stator fixing process Ms can be suppressed, and thus the increase in the manufacturing hours and manufacturing costs of the electric actuator 1 can be suppressed.

[0083] According to the present embodiment, the electric actuator 1 includes a stator cover 40 which is arranged on the upper side of the stator 30, i.e., on one axial side, and in contact with the stator 30 in the axial direction. The housing 10 includes a cylindrical housing body 11, the housing body 11 includes an opening 12b which is open on the upper side, and the housing body 11 includes a first positioning portion 12c which supports the stator 30 from the lower side, i.e., on the other axial side. The surface of the stator cover 40 which faces radially outward contacts the surface of the housing body 11 which faces radially inward in the radial direction. A first circumferential groove 12g is provided on the radially inner surface of the shell body 11 and is recessed radially outward and extends circumferentially. A second circumferential groove 42a is provided on the radially outer surface of the stator cover 40 and is recessed radially inward, extends circumferentially, and is radially opposite to the first circumferential groove 12g. An adhesive 55 is filled in a space portion 50 formed by the first circumferential groove 12g and the second circumferential groove 42a and spans the interior of the first circumferential groove 12g and the interior of the second circumferential groove 42a.

[0084] In the structure in which the stator 30 is pressed into and fixed to the housing body 11, when the interference is too large, the press-in load applied to the housing body 11 becomes large. Therefore, when the housing body 11 is made of resin, cracks may occur in the housing body 11. In addition, when the interference is too small, when the temperature of the electric actuator 1 rises, the press-in load between the housing body 11 and the stator 30 is easily reduced due to the thermal expansion of the housing body 11. Therefore, the axial position of the stator 30 relative to the housing body 11 may be offset. In particular, when the housing body 11 is made of resin, the thermal expansion of the housing body 11 is large, so the press-in load between the housing body 11 and the stator 30 is reduced, and the axial position of the stator 30 relative to the housing body 11 is easily offset. Therefore, in the electric actuator of this structure, it is necessary to improve the dimensional accuracy of the housing body 11 and the stator 30.

[0085] In contrast, in the present embodiment, the stator cover 40 supporting the stator 30 from the upper side can be fixed to the housing body 11 by the adhesive 55 filled in the space portion 50. Therefore, even if the housing body 11 and the stator cover 40 are not fixed by press-fitting, the positional deviation of the stator cover 40 in the axial direction relative to the housing body 11 can be suppressed. In addition, as described above, the stator 30 can be supported from both sides in the axial direction by the first positioning portion 12c of the housing body 11 and the stator cover 40. Therefore, even if the housing body 11 and the stator 30 are not fixed by press-fitting, the positional deviation of the stator 30 in the axial direction relative to the housing body 11 can be suppressed. As a result, the forces applied to the housing body 11 from the stator 30 and the stator cover 40 can be reduced, so even if the housing body 11 is made of resin, the generation of cracks in the housing body 11 can be suppressed. Therefore, it is easy to relax the dimensional accuracy of the housing body 11, the stator cover 40, and the stator 30, so it is possible to suppress the increase in the manufacturing cost of the housing body 11, the stator cover 40, and the stator 30. Therefore, it is possible to suppress an increase in the manufacturing cost of the electric drive 1 .

[0086] In addition, in the present embodiment, as described above, the stator 30 and the stator cover 40 are respectively fitted with a gap relative to the housing body 11. Therefore, in the first step S1 of the stator fixing process Ms, when the stator 30 is mounted on the housing body 11, it is easy to reduce the force of pressing the stator 30 downward. In addition, in the second step S2 of the stator fixing process Ms, when the stator cover 40 is mounted on the housing body 11, it is easy to reduce the force of pressing the stator cover 40 downward. Therefore, the stator 30 and the stator cover 40 can be easily mounted on the housing body 11, so that the increase in the manufacturing man-hours of the stator fixing process Ms can be suppressed. Therefore, the increase in the manufacturing man-hours and manufacturing costs of the electric actuator 1 can be suppressed.

[0087] According to the present embodiment, the first circumferential groove 12g and the second circumferential groove 42a extend all around the circumference. Thus, the space portion 50 can be formed all around the circumference, and the housing body 11 and the stator cover 40 can be fixed all around the circumference by the adhesive 55. Therefore, the stator cover 40 can be fixed to the housing body 11 more firmly, and the position of the stator 30 relative to the housing body 11 can be more appropriately suppressed from being offset in the axial direction.

[0088] According to the present embodiment, the stator cover 40 has a connection portion 43 that connects the space portion 50 and the space inside the housing 10. Unlike the present embodiment, when the stator cover 40 does not have a structure of the connection portion 43, in the second step S2 of the stator fixing process Ms, after the liquid adhesive 55 is filled in advance in the first peripheral groove 12g and the second peripheral groove 42a, the stator cover 40 is mounted on the housing body 11. In this case, in order to prevent the liquid adhesive 55 filled in the second peripheral groove 42a of the stator cover 40 from leaking out from the second peripheral groove 42a, it is necessary to insert the stator cover 40 into the housing body 11 while stabilizing the posture of the stator cover 40 and mount it on the housing body 11. Therefore, the operation of mounting the stator cover 40 on the housing body 11 becomes complicated. In contrast, in the present embodiment, in the second step S2 of the stator fixing process Ms, after the stator cover 40 is mounted on the housing body 11, the liquid adhesive 55 can be filled into the interior of the space portion 50 via the connecting portion 43. Therefore, the stator cover 40 can be easily mounted on the housing body 11. Therefore, the increase in the working hours of the stator fixing process Ms can be suppressed, and thus the increase in the manufacturing hours and manufacturing cost of the electric actuator 1 can be suppressed.

[0089] According to the present embodiment, a plurality of connection parts 43 are arranged at intervals from each other along the circumferential direction. Therefore, at least one connection part 43 can be used as a filling hole for filling the space part 50 with liquid adhesive 55, and at least one other connection part 43 can be used as an exhaust hole for exhausting the air in the space part 50 to the outside of the space part 50. Specifically, in the present embodiment, the first connection part 43a can be used as a filling hole, and the second connection part 43b can be used as an exhaust hole. Therefore, when the liquid adhesive 55 is filled into the space part 50, it is possible to suppress the air from being drawn into the liquid adhesive 55. Thus, it is possible to suppress the generation of pores in the cured adhesive 55, and thus it is possible to improve the bonding strength between the housing body 11 and the stator cover 40. Thus, it is possible to more appropriately suppress the axial positional deviation of the stator cover 40 relative to the housing body 11, and thus it is possible to more appropriately suppress the axial positional deviation of the stator 30 relative to the housing body 11.

[0090] In addition, in the present embodiment, as described above, in the third step S3 of the stator fixing process Ms, when the operator or the like fills the space portion 50 with the liquid adhesive 55, after confirming that the liquid adhesive 55 leaks out from the second connection portion 43b used as the exhaust hole, the operator can stop filling the liquid adhesive 55. Thus, the liquid adhesive 55 can be more preferably filled all around the circumference of the space portion 50. Therefore, the bonding strength between the housing body 11 and the stator cover 40 can be further improved, and thus the positional deviation of the stator 30 in the axial direction relative to the housing body 11 can be more preferably suppressed.

[0091] According to the present embodiment, two connection parts 43a and 43b among the plurality of connection parts 43 are arranged at positions sandwiching the motor axis J1 in the radial direction. Therefore, as described above, it is easy to make the length of the first space part 50a the same as the length of the second space part 50b. Therefore, in the third step S3 of the stator fixing process Ms, the deviation of the time when the liquid adhesive 55 passing through the first space part 50a and the liquid adhesive 55 passing through the second space part 50b reach the second connection part 43b can be reduced. Therefore, after confirming that the liquid adhesive 55 leaks from the second connection part 43b, the operator stops filling the liquid adhesive 55, thereby making it possible to more appropriately fill the liquid adhesive 55 throughout the circumference of the space part 50. Therefore, the bonding strength between the housing body 11 and the stator cover 40 can be further improved, so that the axial positional deviation of the stator 30 relative to the housing body 11 can be more appropriately suppressed.

[0092] According to the present embodiment, the inside of the connection portion 43 is filled with the adhesive 55. Therefore, in the third step S3 of the stator fixing process Ms, the operator or the like can stop filling the liquid adhesive 55 into the space portion 50 after confirming that the liquid adhesive 55 leaks out from the second connection portion 43b. Thus, as described above, the liquid adhesive 55 can be more appropriately filled throughout the circumference of the space portion 50. Therefore, the bonding strength between the housing body 11 and the stator cover 40 can be more stably improved, and thus the axial positional deviation of the stator 30 relative to the housing body 11 can be more appropriately suppressed.

[0093] According to the present embodiment, the housing body 11 and the stator cover 40 are respectively made of resin. Therefore, it is easy to reduce the difference between the linear expansion coefficient of the housing body 11 and the linear expansion coefficient of the stator cover 40. Therefore, even if the temperature of the electric actuator 1 changes, it is easy to reduce the difference between the thermal contraction amount of the housing body 11 and the thermal contraction amount of the stator cover 40. Therefore, even if the temperature of the electric actuator 1 changes, it is easy to suppress the increase of the load applied to the housing body 11 and the stator cover 40. Therefore, it is easy to suppress the generation of cracks in the housing body 11 and the stator cover 40.

[0094] <Second embodiment>

[0095] Fig. 9 and Fig.10 1 is a cross-sectional view showing a part of the 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.

[0096] like Fig. 9 and Fig.10As shown, in this embodiment, the cover fixing portion 142 of the stator cover 140 does not have a connection portion. The other structures of the stator cover 140 of this embodiment are the same as those of the stator cover 40 of the first embodiment described above.

[0097] like Fig. 9 and Fig.10 As shown, in the present embodiment, the first storage portion 112 of the shell 110 has a connecting portion 118. In the present embodiment, the connecting portion 118 is a hole extending radially inward from the outer peripheral surface of the first peripheral wall portion 112a of the shell body 111. The connecting portion 118 is connected to the first peripheral groove 12g. Thus, the connecting portion 118 connects the space portion 50 and the space outside the shell 10. In the present embodiment, the shell body 111 has a plurality of connecting portions 118. In the present embodiment, the shell body 111 has two connecting portions 118. The connecting portion 118 includes a first connecting portion 118a and a second connecting portion 118b. In addition, the shell body 111 may also have more than three connecting portions 118.

[0098] like Fig. 9 As shown in FIG. 1 , the first connection portion 118a is provided at the edge of the left side (-X side) of the first peripheral wall portion 112a. The first connection portion 118a connects the space portion 50 and the space outside the housing 110. Fig.10 As shown, the second connection portion 118b is provided at the edge of the right side (+X side) of the first circumferential wall portion 112a. That is, a plurality of connection portions 118 are arranged at intervals from each other in the circumferential direction. The second connection portion 118b connects the space portion 50 and the space outside the housing 110. In addition, the two connection portions 118a and 118b are arranged at positions that clamp the motor axis J1 in the radial direction. Therefore, although illustration is omitted, similarly to the above-mentioned first embodiment, the circumferential length of the first space portion 50a is the same length as the circumferential length of the second space portion 50b. As shown in FIG. Fig. 9 and Fig.10 As shown, the inside of the first connection part 118a and the inside of the second connection part 118b are filled with adhesive 55.

[0099] Next, the stator fixing process Ms of the electric actuator 101 of the present embodiment is described. The stator fixing process Ms includes a first step S1 of mounting the various parts of the motor 9 on the housing body 111, a second step S2 of mounting the stator cover 140 on the housing body 111, and a third step S32 of filling the space 50 with the adhesive 55. The first step S1 and the second step S2 of the present embodiment are the same as the first step S1 and the second step S2 of the first embodiment described above.

[0100] In the third step S32, first, the operator or the like inserts the nozzle of the filling jig (not shown) from the outside of the housing body 111 into the housing body 111. Fig. 9 Next, the operator fills the space 50 with a liquid adhesive 55 (not shown) from the first connection portion 118a using a filling jig. The liquid adhesive 55 that flows from the first connection portion 118a into the space 50 flows toward the second connection portion 118b in the first space 50a and the second space 50b, respectively, and reaches Fig.10 The second connection portion 118b shown. When the operator confirms that the liquid adhesive 55 leaks out of the housing body 111 through the second connection portion 118b, the filling of the liquid adhesive 55 is completed. Then, when the operator solidifies the liquid adhesive 55, the stator cover 140 is fixed to the housing body 111. When the stator cover 140 is fixed to the housing 111, the third step S32 is completed. When the third step S32 is completed, the stator fixing process Ms is completed.

[0101] According to the present embodiment, the connection portion 118 is a hole provided in the housing body 111 and extending radially outward from the space portion 50. Therefore, in the third step S32 of the stator fixing process Ms, the nozzle of the filling jig can be easily inserted into the inside of the first connection portion 118a from the outside of the housing body 11. Therefore, in the third step S32, the workability of the operation of filling the space portion 50 with the liquid adhesive 55 can be improved. Therefore, the increase in the working hours of the stator fixing process Ms can be suppressed, and thus the increase in the manufacturing hours and manufacturing costs of the electric actuator 101 can be suppressed.

[0102] In addition, in the present embodiment, the inside of the connection portion 118 is filled with the adhesive 55. Therefore, in the third step S32 of the stator fixing process Ms, after confirming that the liquid adhesive 55 leaks out from the second connection portion 118b, the filling of the liquid adhesive 55 into the space portion 50 can be stopped. Thus, similarly to the first embodiment described above, the liquid adhesive 55 can be more appropriately filled throughout the circumference of the space portion 50. Therefore, the bonding strength between the housing body 111 and the stator cover 140 can be further improved, and thus the positional deviation of the stator 30 in the axial direction relative to the housing body 111 can be more appropriately suppressed.

[0103] In addition, in the present embodiment, the second connection portion 118b is connected to the external space of the housing 10, so that the operator can easily confirm that the liquid adhesive 55 leaks from the second connection portion 118b to the outside of the housing body 111. Thus, the operability of the third step S32 can be improved, so that the increase in the manufacturing man-hours of the electric actuator 101 can be suppressed.

[0104] 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 gist of the present invention. In addition, the present invention is not limited to the embodiments.

[0105] The position of the connection part is not limited to the present embodiment. For example, the first connection part may be provided at the right side of the housing fixing part or the first peripheral wall part, and the second connection part may be provided at the left side of the housing fixing part or the first peripheral wall part. In addition, the first connection part and the second connection part may not be arranged at the position sandwiching the motor axis in the radial direction. The inside of the connection part may not be filled with adhesive.

[0106] 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, and the output shaft and the output gear may also be part of the same single component.

[0107] The application of the electric drive of the utility model is not particularly limited. The electric drive can be mounted on a drive device of a shift-by-wire mode driven based on a shift operation of a driver. In addition, the electric drive can also be mounted on equipment other than a vehicle. In addition, the various structures described in this specification can be appropriately combined within the scope of non-contradiction.

[0108] Furthermore, the present technology can adopt the following structures.

[0109] (1) An electric drive, 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 for reducing the rotation of the motor shaft and transmitting it to an output shaft; a stator cover disposed on one axial side of the stator and in axial contact with the stator; and a housing in which the motor, the transmission mechanism, and the stator cover are respectively housed, the housing comprising: a cylindrical housing body having an opening portion opened on one axial side; and a cover member covering the opening portion, the housing body comprising: a housing body supporting the stator from the other axial side a first positioning portion; and a second positioning portion that determines the radial position of the stator relative to the housing body, the radially outward surface of the stator cover is in radial contact with the radially inward surface of the housing body, the radially inward surface of the housing body is provided with a first circumferential groove that is recessed radially outward and extends circumferentially, the radially outward surface of the stator cover is provided with a second circumferential groove that is recessed radially inward, extends circumferentially and is radially opposite to the first circumferential groove, and the space formed by the first circumferential groove and the second circumferential groove is filled with an adhesive that spans the interior of the first circumferential groove and the interior of the second circumferential groove.

[0110] (2) The electric actuator according to (1), wherein the first circumferential groove and the second circumferential groove each extend throughout the circumference in the circumferential direction.

[0111] (3) The electric actuator according to (1) or (2), wherein at least one of the stator cover and the housing body has a connection portion that connects the space portion and a space inside the housing.

[0112] (4) The electric actuator according to (3), wherein a plurality of the connection portions are arranged at intervals in the circumferential direction.

[0113] (5) The electric actuator according to claim (4), wherein two of the plurality of connection portions are disposed at positions sandwiching the motor axis in a radial direction.

[0114] (6) The electric actuator according to any one of items (3) to (5), wherein the interior of the connecting portion is filled with an adhesive.

[0115] (7) The electric actuator according to any one of solutions (3) to (6), wherein the connection portion is a hole provided in the stator cover and extending from the space portion to one side in the axial direction.

[0116] (8) The electric actuator according to any one of means (1) to (7), wherein the housing body and the stator cover are each made of resin.

Claims

1. An electric drive, characterized in that: have: A motor having a rotor having a motor shaft rotatable about a motor axis and a stator arranged radially outside the rotor; A transmission mechanism for reducing the speed of rotation of the motor shaft and transmitting it to the output shaft; a stator cover disposed on one axial side of the stator and in contact with the stator in the axial direction; and The motor, the transmission mechanism and the stator cover are respectively housed in a housing. The housing has: A cylindrical housing body having an opening portion opened on one axial side; and a cover member covering the opening, The housing body has: A first positioning portion that supports the stator from the other axial side; and a second positioning portion for determining a radial position of the stator relative to the housing body, The radially outward-facing surface of the stator cover is in contact with the radially inward-facing surface of the housing body in the radial direction. A first circumferential groove is provided on a surface of the housing body facing radially inward and recessed radially outward and extending in the circumferential direction. A second circumferential groove is provided on a surface of the stator cover facing radially outward, which is recessed radially inward, extends in the circumferential direction and is radially opposite to the first circumferential groove. A space formed by the first circumferential groove and the second circumferential groove is filled with an adhesive extending across the inside of the first circumferential groove and the inside of the second circumferential groove.

2. The electric drive according to claim 1, characterized in that The first circumferential groove and the second circumferential groove each extend all around the circumference in the circumferential direction.

3. The electric drive according to claim 1, characterized in that: At least one of the stator cover and the housing body includes a connection portion that connects the space portion and a space inside the housing.

4. The electric drive according to claim 3, characterized in that: A plurality of the connection portions are arranged at intervals in the circumferential direction.

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

6. The electric drive according to any one of claims 3 to 5, characterized in that: The connection portion is filled with an adhesive.

7. The electric drive according to any one of claims 3 to 5, characterized in that: The connection portion is a hole provided in the stator cover and extending from the space portion to one side in the axial direction.

8. The electric drive according to any one of claims 1 to 5, characterized in that: The housing body and the stator cover are each made of resin.

Images