JP2022057439A - Electric actuator - Google Patents

Abstract

To provide a compact electric actuator.SOLUTION: An electric actuator 10 has: a motor shaft 21 which is rotationally driven around a central axis by a motor part 20, and which has a through-hole 25 in the axial direction; and an output shaft 41 whose one side in the axial direction is inserted through the through-hole, and to which rotation of the motor shaft is transmitted. On the other side in the axial direction of the motor shaft, there is provided an axially recessed part 26 which is continuous with the through-hole. On the other side in the axial direction of the output shaft, there is provided a coupling part 42 to which a driven body, where rotation of the output shaft is transmitted, is coupled from the other side in the axial direction. One side in the axial direction of the coupling part is inserted into the recessed part.SELECTED DRAWING: Figure 1

Description

The present invention relates to an electric actuator.

An electric actuator in which the rotation of a motor unit is transmitted via a speed reducer is known. For example, Patent Document 1 discloses an electric actuator in which a motor shaft, a reduction gear, and a spline as an interface with the vehicle side are configured on one shaft, and the spline protrudes.

Japanese Unexamined Patent Publication No. 2018-126032

Since many functional parts are configured on one axis, there is a problem that the physique in the axial direction becomes large.

The present invention has been made in consideration of the above points, and an object of the present invention is to provide a small electric actuator.

One aspect of the electric actuator of the present invention is a motor shaft that is rotationally driven by a motor unit around a central axis and has a through hole in the axial direction, and one side of the through hole is passed in the axial direction to rotate the motor shaft. The motor shaft has an output shaft to which the motor shaft is transmitted, an axial recess portion connected to the through hole is provided on the other side in the axial direction of the motor shaft, and the output is provided on the other side in the axial direction of the output shaft. A connecting portion is provided in which the driven body to which the rotation of the shaft is transmitted is connected from the other side in the axial direction, and the one side in the axial direction of the connecting portion is inserted into the recessed portion.

According to one aspect of the present invention, a small electric actuator can be provided.

FIG. 1 is a cross-sectional view showing an electric actuator of the present embodiment. FIG. 2 is a cross-sectional view showing the electric actuator of the present embodiment, and is a cross-sectional view taken along the line II-II in FIG. FIG. 3 is a schematic cross-sectional view showing a part of the electric actuator of the present embodiment.

Hereinafter, the electric actuator according to the embodiment of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the following embodiments, and can be arbitrarily changed within the scope of the technical idea of the present invention. Further, in the following drawings, in order to make each configuration easy to understand, the scale and number of each structure may be different from the actual structure.

In each figure, the Z-axis direction is a vertical direction with the positive side as the upper side and the negative side as the lower side. The axial direction of the central axis J1 shown in each figure is parallel to the Z-axis direction, that is, the vertical direction. In the following description, unless otherwise specified, the direction parallel to the axial direction of the central axis J1 is simply referred to as "axial direction". Unless otherwise specified, the radial direction centered on the central axis J1 is simply referred to as "diametrical direction", and the circumferential direction centered on the central axis J1 is simply referred to as "circumferential direction".

In the present embodiment, the upper side corresponds to one side in the axial direction, and the lower side corresponds to the other side in the axial direction. It should be noted that the upper side and the lower side are simply names for explaining the relative positional relationship of each part, and the actual arrangement relationship or the like may be an arrangement relationship or the like other than the arrangement relationship or the like indicated by these names. ..

The electric actuator 10 of the present embodiment shown in FIGS. 1 to 3 is, for example, an electric actuator mounted on a vehicle. As shown in FIGS. 1 and 3, the electric actuator 10 includes a case 11, a partition member 15, a motor portion 20 having a motor shaft 21 that rotates about a central axis J1, a first bearing 53, and a second bearing. It includes a bearing 51, a third bearing 52, a reduction mechanism 30, an output shaft 41, a magnetic sensor 63, a circuit board 70, and a bus bar holder 140.

As shown in FIG. 1, the case 11 houses a partition member 15, a motor unit 20, a motor shaft 21, a reduction mechanism 30, an output shaft 41, a magnetic sensor 63, a circuit board 70, and a bus bar holder 140. The case 11 has a lower case 11A that opens upward and an upper case 11B that is fixed to the opening of the lower case 11A.

The lower case 11A has a cylindrical shape extending in the axial direction about the central axis J1. The lower case 11A has a substrate accommodating portion 13a, a case cylinder portion 13b, an output portion accommodating portion 13c, and a bearing holding portion 13d. The board accommodating portion 13a is a portion accommodating the circuit board 70 and the bus bar holder 140. The substrate accommodating portion 13a opens upward. The substrate accommodating portion 13a is configured inside the upper portion of the lower case 11A in the radial direction. The bottom surface of the board accommodating portion 13a is a support surface 12 that supports and fixes the circuit board 70 and the bus bar holder 140. The support surface 12 faces upward.

The case cylinder portion 13b surrounds the radial outside of the motor portion 20. The output unit accommodating unit 13c is a portion accommodating the output unit 46 described later. The bearing holding portion 13d holds the third bearing 52. The bearing holding portion 13d extends upward from the lower end portion of the case 11 with the central axis J1 as the center.

The upper case 11B is a container-shaped member having a recess 16a that opens downward. The upper case 11B and the lower case 11A are fastened by a plurality of bolts that penetrate the upper case 11B in the axial direction. In the present embodiment, the upper case 11B corresponds to a lid portion that covers the opening of the lower case 11A from above. The upper case 11B has a bearing holding portion 16b. The bearing holding portion 16b holds the first bearing 53. The bearing holding portion 16b extends downward with the central axis J1 as the center.

The central axis of the motor unit 20 is the central axis J1. As shown in FIG. 1, the motor unit 20 includes a rotor 22 and a stator 23. The rotor 22 includes a motor shaft 21, a rotor core 22a, and a magnet 40.

The motor shaft 21 includes a first shaft portion 21a, a second shaft portion 21b, and a through hole 25. The first shaft portion 21a extends in the axial direction and is located above the motor shaft 21. The second shaft portion 21b extends in the axial direction and is located below the motor shaft 21. The diameter of the second shaft portion 21b is larger than the diameter of the first shaft portion 21a. More specifically, the outer diameter of the second shaft portion 21b is larger than the outer diameter of the first shaft portion 21a. The second shaft portion 21b is an eccentric shaft portion centered on the eccentric shaft J2 that is eccentric with respect to the central shaft J1. The eccentric axis J2 is parallel to the central axis J1. The through hole 25 extends about the central axis J1. Therefore, the first shaft portion 21a has a cylindrical shape extending about the central shaft J1. The second shaft portion 21b has an axially recessed portion 26 on the lower side. The recessed portion 26 extends about the eccentric axis J2. Therefore, the second shaft portion 21b has a cylindrical shape extending about the eccentric shaft J2. The upper side of the recess 26 is connected to the lower side of the through hole 25. In the motor shaft 21, the second shaft portion 21b is rotatably supported around the eccentric shaft J2 by the third bearing 52.

The output shaft 41 transmits the rotation of the motor shaft 21 via the reduction mechanism 30. The output shaft 41 has a shaft portion 41a and a connecting portion 42. The shaft portion 41a is located on the upper side, and the connecting portion 42 is located on the lower side. The shaft portion 41a is a columnar shape extending around the central shaft J1. The upper side of the shaft portion 41a is passed through the through hole 25 of the motor shaft 21. The upper end of the shaft portion 41a projects upward from the motor shaft 21. The upper end of the shaft portion 41a protruding upward from the motor shaft 21 is rotatably supported around the central shaft J1 by the first bearing 53. The upper end of the motor shaft 21 is supported by the case 11 via the first bearing 53.

The lower end of the connecting portion 42 projects below the motor shaft 21. The lower end of the connecting portion 42 projecting to the lower side of the motor shaft 21 is rotatably supported around the central axis J1 by the second bearing 51. The lower end of the motor shaft 21 is supported by the case 11 via a second bearing 51. The end of the output shaft 41 in the axial direction is rotatably supported around the central axis J1 by the first bearing 53 and the second bearing 51. Therefore, the motor shaft 21 through which the shaft portion 41a of the output shaft 41 is passed through the through hole 25 is rotatably supported around the central shaft J1 by the shaft portion 41a.

The first bearing 53, the second bearing 51, and the third bearing 52 are rolling bearings having an inner ring and an outer ring located radially outside the inner ring, respectively. In the present embodiment, the first bearing 53, the second bearing 51, and the third bearing 52 are ball bearings in which, for example, an inner ring and an outer ring are connected via a plurality of balls.

The upper side of the connecting portion 42 is inserted into the recessed portion 26 of the motor shaft 21. Since the upper side of the connecting portion 42 is inserted into the recessed portion 26 of the motor shaft 21, the axial length of the output shaft 41 can be shortened. Therefore, the axial length of the electric actuator 10 can be shortened to reduce the size.

The connecting portion 42 has a cylindrical tubular portion 44 extending about the central axis J1. A connecting recess 45 is provided in the inner diameter of the tubular portion 44. The connecting recess 45 is recessed upward from the lower end of the output shaft 41. The connecting recess 45 has a substantially circular shape centered on the central axis J1 when viewed along the axial direction. A plurality of spline grooves are provided on the inner peripheral surface of the connecting recess 45 along the circumferential direction. Another member that outputs the driving force of the electric actuator 10 is inserted into the connecting recess 45 and connected. Other members are, for example, manual shafts in vehicles. The electric actuator 10 drives the manual shaft based on the shift operation of the driver, and switches the gear of the vehicle.

Since the connecting portion 42 has the connecting recess 45 recessed upward, the axial length of the output shaft 41 can be shortened as compared with the case where the connecting portion 42 has a shaft shape protruding downward. Therefore, the axial length of the electric actuator 10 can be shortened to reduce the size. The first bearing 53 is held by the bearing holding portion 16b provided in the case 11, and the second bearing 51 is held by the bearing holding portion 13d provided in the case 11, so that the output shaft 41 is coaxial with the central axis J1. The degree can be improved. The first bearing 53 is held by the bearing holding portion 16b provided in the case 11, and the second bearing 51 is held by the bearing holding portion 13d provided in the case 11, so that the first bearing 53 and the second bearing 51 are held. It is not necessary to separately provide the bearing, which can contribute to cost reduction and miniaturization of the electric actuator 10.

The rotor core 22a is fixed to the outer peripheral surface of the motor shaft 21. More specifically, the rotor core 22a is fixed to the outer peripheral surface of the first shaft portion 21a. The peripheral edge of the rotor core 22a is supported from below by a partition member 15 described later, which is supported from below by the lower case 11A. The partition member 15 is a support member that supports the rotor core 22a from below. The magnet 40 is fixed to the outside of the rotor core 22a in the radial direction. A plurality of magnets 40 are arranged at intervals in the circumferential direction.

The stator 23 is located radially outside the rotor 22. The stator 23 has a stator core 23a and a plurality of coils 23b. The stator core 23a is an annular shape that surrounds the radial outer side of the rotor 22. The outer peripheral surface 24a of the stator core 23a is fixed to the inner peripheral surface of the case cylinder portion 13b. The plurality of coils 23b are mounted on the teeth of the stator core 23a, for example, via an insulator (not shown).

As shown in FIG. 2, the stator 23 has an outer peripheral surface 24b on the inner side in the radial direction with respect to the outer peripheral surface 24a. The outer peripheral surface 24b is arranged for each magnetic pole. The outer peripheral surface 24b when viewed in the axial direction is orthogonal to the center of the magnetic pole in the circumferential direction. The outer peripheral surface 24b of the stator 23 is provided with a groove portion 27 that is recessed inward in the radial direction. The groove portion 27 extends in the axial direction. The groove portions 27 are arranged on the upper side and the lower side of the outer peripheral surface 24a of the stator core 23a, respectively. A plurality of groove portions 27 are arranged at intervals in the circumferential direction.

The bus bar holder 140 is arranged above the rotor 22. The bus bar holder 140 has a ring plate shape. As shown in FIG. 1, the bus bar holder 140 has a spacer 143. The spacer 143 has a cylindrical shape extending in the axial direction. The spacer 143 projects upward from the bus bar holder 140. The upper end of the spacer 143 is in contact with the lower side of the circuit board 70. The bus bar holder 140 and the circuit board 70 are screwed to the support surface 12 of the lower case 11A by bolts 144 penetrating the circuit board 70 and the spacer 143 from above. For example, three bolts 144 are provided. The bus bar holder 140 and the circuit board 70 are screwed from above at a position where they overlap the spacer 143 when viewed in the axial direction with bolts 144. The screwed circuit board 70 is arranged on the upper side of the bus bar holder 140 with a gap. The dimension of the gap between the circuit board 70 and the bus bar holder 140 is the dimension in which the spacer 143 projects upward from the bus bar holder 140.

The bus bar holder 140 has a peripheral wall portion 141 extending downward. The peripheral wall portion 141 is located radially outside the outer peripheral surface 24b of the stator 23. The peripheral wall portion 141 is located radially inside the outer peripheral surface 24a of the stator 23. The lower end of the peripheral wall portion 141 comes into contact with the upper side of the stator 23 when the bus bar holder 140 is screwed to the support surface 12.

When the bus bar holder 140 is screwed to the support surface 12 of the lower case 11A, the lower end of the peripheral wall portion 141 comes into contact with the upper side of the stator 23, so that the stator 23 is supported from the lower side by the partition member 15. Is axially positioned and fixed to the lower case 11A.

As shown in FIG. 2, the peripheral wall portion 141 of the bus bar holder 140 has a protrusion 142 protruding inward in the radial direction. The protrusion 142 extends in the axial direction. The position of the protrusion 142 in the circumferential direction of the protrusion 142 is the same as the position of the groove 27 of the stator 23 in the circumferential direction. The protrusion 142 faces the groove 27 in the radial direction. The protrusion 142 protruding inward in the radial direction of the peripheral wall portion 141 is inserted into the groove portion 27. The bus bar holder 140 in which the protrusion 142 is inserted into the groove 27 is positioned in the circumferential direction with the stator 23. When the bus bar holder 140 is accommodated in the substrate accommodating portion 13a while inserting the protrusion 142 from the upper side with respect to the groove portion 27 opening on the upper side, the bus bar holder 140 is positioned in the circumferential direction with respect to the stator 23 and the lower case 11A. can. Therefore, when the bus bar holder 140 is screwed to the support surface 12 of the lower case 11A, the bus bar holder 140, the stator 23, and the lower case 11A can be positioned with each other in the circumferential direction and the axial direction.

The bus bar holder 140 holds a magnetic sensor 63, a conductive wire 64, and a plurality of bus bars 150. In the present embodiment, the bus bar holder 140, the magnetic sensor 63, the conductive wire 64, the spacer 143, and the plurality of bus bars 150 are resin-molded and integrated bodies. More specifically, the bus bar holder 140 is made by insert molding using a magnetic sensor 63, a conductive wire 64, a spacer 143, and a bus bar 150 as insert members.

The magnetic sensor 63 can detect the magnetic field of the magnet 40. The magnetic sensor 63 is, for example, a Hall element. The magnetic sensor 63 is fixed to the lower side of the bus bar holder 140. The magnetic sensor 63 is arranged on the upper side of the magnet so as to face each other with a gap. As shown in FIG. 2, three magnetic sensors 63 are arranged at intervals in the circumferential direction. The circumferential spacing between the magnetic sensors 63 is the same as the circumferential spacing of the magnetic poles. The magnetic sensor 63 detects the rotation position of the magnet 40 by detecting the magnetic field of the magnet 40, and detects the rotation of the motor shaft 21.

According to the electric actuator 10 of the present embodiment, since the magnetic sensor 63 arranged in the bus bar holder 140 detects the magnetic field of the magnet 40, an extra substrate for mounting the magnetic sensor is not required separately. According to the electric actuator 10 of the present embodiment, the magnetic sensor 63 and the bus bar holder 140 are resin-molded and integrated, and the bus bar holder 140 is assembled by screwing it to the support surface 12 of the lower case 11A. Occasionally, it can be positioned in the circumferential direction and the axial direction with the stator 23. According to the electric actuator 10 of the present embodiment, it is possible to prevent the advance angle deviation from occurring depending on the assembly accuracy and the deterioration of the rotation control accuracy of the motor.

One end of the conductive wire 64 is electrically connected to the magnetic sensor 63. The conductive wire 64 may be a terminal extending from the magnetic sensor 63, or may be a bus bar having one end connected to the magnetic sensor 63. The conductive wire 64 penetrates the bus bar holder 140 from the inside of the bus bar holder 140, and the other end side is electrically connected to the circuit board 70 by a connection method such as soldering, welding, or press fitting.

The circuit board 70 has a plate shape extending in a plane orthogonal to the axial direction. The circuit board 70 is housed in the lower case 11A. More specifically, the circuit board 70 is housed in the board accommodating portion 13a. The circuit board 70 is a board that is electrically connected to the motor unit 20. The circuit board 70 controls, for example, the current supplied to the motor unit 20. That is, for example, an inverter circuit is mounted on the circuit board 70.

As shown in FIG. 3, one end 150a of the bus bar 150 grips the coil leader wire drawn from the coil 23b of the stator 23 and is connected to the coil 23b by soldering or welding. The other end 150b of the bus bar 150 projects upward from the upper surface of the bus bar holder 140. In the present embodiment, the other end portion 150b of the bus bar 150 penetrates the circuit board 70 from the lower side to the upper side. The end portion 150b is electrically connected to the circuit board 70 at a position penetrating the circuit board 70 by a connection method such as soldering, welding, or press fitting. As a result, the circuit board 70 is electrically connected to the motor unit 20 via the bus bar 150.

The deceleration mechanism 30 is arranged on the radial outside of the second shaft portion 21b of the motor shaft 21 and the radial outside of the connecting portion 42 of the output shaft 41. The deceleration mechanism 30 is arranged below the motor unit 20. The partition member 15 is arranged between the stator 23 and the speed reduction mechanism 30 in the axial direction. The reduction mechanism 30 has an external tooth gear 31, an internal tooth gear 32, an output unit 46, and a plurality of projecting portions 43.

The external tooth gear 31 has an annular plate shape that extends in the radial direction of the eccentric shaft J2 with the eccentric shaft J2 of the eccentric shaft portion 21b as the center. A gear portion is provided on the radial outer surface of the external tooth gear 31. The gear portion of the external tooth gear 31 has a plurality of tooth portions arranged along the outer circumference of the external tooth gear 31.

The external tooth gear 31 is connected to the motor shaft 21. More specifically, the external tooth gear 31 is connected to the eccentric shaft portion 21b of the motor shaft 21 via a third bearing 52. As a result, the motor shaft 21 is connected to the deceleration mechanism 30. The external tooth gear 31 is fitted to the outer ring of the third bearing 52 from the outside in the radial direction. The eccentric shaft portion 21b is fitted to the inner ring of the third bearing 52 from the outside in the radial direction. As a result, the third bearing 52 connects the motor shaft 21 and the external tooth gear 31 so as to be relatively rotatable around the eccentric shaft J2.

In the present embodiment, the external tooth gear 31 has a plurality of holes 31a. In the present embodiment, the hole portion 31a penetrates the external tooth gear 31 in the axial direction. The plurality of hole portions 31a are arranged along the circumferential direction. More specifically, the plurality of hole portions 31a are arranged at equal intervals over one circumference along the circumferential direction centered on the eccentric axis J2. The hole portion 31a has a circular shape when viewed in the axial direction. The inner diameter of the hole 31a is larger than the outer diameter of the protruding portion 43. The hole portion 31a may be a hole having a bottom portion.

The internal tooth gear 32 is located radially outside the external tooth gear 31 and is an annular shape surrounding the external tooth gear 31. In the present embodiment, the internal tooth gear 32 is an annular shape centered on the central axis J1. The radial outer edge portion of the internal tooth gear 32 is arranged and fixed to the stepped portion 13e provided on the inner peripheral surface of the case cylinder portion 13b and recessed in the radial direction. As a result, the deceleration mechanism 30 is held in the lower case 11A. The internal tooth gear 32 meshes with the external tooth gear 31. A gear portion is provided on the radial inner surface of the internal tooth gear 32. The gear portion of the internal tooth gear 32 has a plurality of tooth portions arranged along the inner circumference of the internal tooth gear 32. In the present embodiment, the gear portion of the internal tooth gear 32 meshes with the gear portion of the external tooth gear 31 only in a part in the circumferential direction.

The output unit 46 has an annular plate shape that extends in the radial direction about the central axis J1. The output unit 46 is located below the external tooth gear 31. The output unit 46 is fixed to the outer peripheral surface of the output shaft 41. More specifically, the output unit 46 is fixed to the outer peripheral surface of the connecting portion 42 of the output shaft 41.

The plurality of protrusions 43 are fixed to the output portion 46, for example, by welding. The plurality of protruding portions 43 project upward from the output portion 46. That is, the plurality of protruding portions 43 project from the output portion 46 toward the external tooth gear 31. The protrusion 43 is columnar. The plurality of protrusions 43 are arranged along the circumferential direction. More specifically, the plurality of protrusions 43 are arranged at equal intervals over one circumference along the circumferential direction centered on the central axis J1.
The number of protrusions 43 is, for example, eight.

The plurality of projecting portions 43 are inserted into the plurality of hole portions 31a, respectively. The outer peripheral surface of the protruding portion 43 is inscribed with the inner peripheral surface of the hole portion 31a. As a result, the plurality of projecting portions 43 swingably support the external tooth gear 31 around the central axis J1 via the inner side surface of the hole portion 31a.

In the present embodiment, the hole portion 31a and the protruding portion 43 overlap with the third bearing 52 and the second shaft portion 21b when viewed along the radial direction. In other words, each of the hole portion 31a, the protruding portion 43, the third bearing 52, and the second shaft portion 21b has a portion located at the same position in the axial direction.

When the motor shaft 21 is rotated around the central axis J1, the second shaft portion 21b, which is an eccentric shaft portion, revolves around the central axis J1 in the circumferential direction. The revolution of the second shaft portion 21b is transmitted to the external tooth gear 31 via the third bearing 52, and the position of the external tooth gear 31 inscribed between the inner peripheral surface of the hole portion 31a and the outer peripheral surface of the protruding portion 43 changes. While doing so, it swings. As a result, the position where the gear portion of the external tooth gear 31 and the gear portion of the internal tooth gear 32 mesh with each other changes in the circumferential direction. Therefore, the rotational force of the motor shaft 21 is transmitted to the internal gear 32 via the external gear 31.

Here, in the present embodiment, since the internal tooth gear 32 is fixed, it does not rotate. Therefore, the external tooth gear 31 rotates around the eccentric shaft J2 due to the reaction force of the rotational force transmitted to the internal tooth gear 32. At this time, the rotation direction of the external tooth gear 31 is opposite to the rotation direction of the motor shaft 21. The rotation of the external tooth gear 31 around the eccentric shaft J2 is transmitted to the output portion 46 via the hole portion 31a and the protruding portion 43. As a result, the output shaft 41 rotates around the central axis J1. In this way, the rotation of the motor shaft 21 is transmitted to the output shaft 41 via the reduction mechanism 30.

The rotation of the output shaft 41 is decelerated with respect to the rotation of the motor shaft 21 by the deceleration mechanism 30. Specifically, in the configuration of the reduction mechanism 30 of the present embodiment, the reduction ratio R of the rotation of the output shaft 41 with respect to the rotation of the motor shaft 21 is represented by R = − (N2-N1) / N2. The minus sign at the beginning of the equation representing the reduction ratio R indicates that the direction of rotation of the output shaft 41 to be decelerated is opposite to the direction of rotation of the motor shaft 21. N1 is the number of teeth of the external tooth gear 31, and N2 is the number of teeth of the internal tooth gear 32. As an example, when the number of teeth N1 of the external gear 31 is 59 and the number of teeth N2 of the internal gear 32 is 60, the reduction ratio R is -1/60.

As described above, according to the reduction mechanism 30 of the present embodiment, the reduction ratio R of the rotation of the output shaft 41 with respect to the rotation of the motor shaft 21 can be made relatively large. Therefore, the rotational torque of the output shaft 41 can be relatively large.

The electric actuator to which the present invention is applied may be any device as long as it can move the target object by being supplied with electric power, and may be a motor without a deceleration mechanism. Further, the electric actuator may be an electric pump including a pump unit driven by a motor unit. The use of the electric actuator is not particularly limited. The electric actuator may be mounted on a shift-by-wire actuator device driven based on the shift operation of the driver. Further, the electric actuator may be mounted on a device other than the vehicle. It should be noted that the configurations described in the present specification can be appropriately combined within a range that does not contradict each other.

10 ... Electric actuator, 12 ... Support surface, 15 ... Support member (partition member), 20 ... Motor part, 21 ... Motor shaft, 21a ... First shaft part, 21b ... Second shaft part (eccentric shaft part), 22 ... Rotor, 23 ... stator, 24b ... outer peripheral surface, 25 ... through hole, 30 ... reduction mechanism, 40 ... magnet, 41 ... output shaft, 45 ... connecting recess, 51 ... second bearing, 52 ... third bearing, 53 ... third 1 bearing, 63 ... magnetic sensor, 64 ... conductive wire, 70 ... circuit board, 140 ... bus bar holder, 141 ... peripheral wall, 142 ... protrusion, 143 ... spacer, 150 ... bus bar, J1 ... central axis, J2 ... eccentric axis

Claims (7)

A motor shaft that is rotationally driven by the motor section around the central axis and has a through hole in the axial direction,
An output shaft through which one side in the axial direction is passed through the through hole and the rotation of the motor shaft is transmitted.
Have,
An axial recess connected to the through hole is provided on the other side of the motor shaft in the axial direction.
On the other side of the output shaft in the axial direction, a connecting portion is provided to which the driven body to which the rotation of the output shaft is transmitted is connected from the other side in the axial direction.
One side of the connecting portion in the axial direction is an electric actuator inserted into the recessed portion. The output shaft has one end in the axial direction and the other end protruding from the motor shaft.
One end of the output shaft in the axial direction is supported by the case via a first bearing.
The electric actuator according to claim 1, wherein the end of the output shaft on the other side in the axial direction has the connecting portion supported by the case via a second bearing. The motor unit includes a rotor that can rotate around the central axis.
The motor shaft is
The first shaft portion fixed to the rotor and
A second shaft portion located on the other side of the first shaft portion in the axial direction and having a diameter larger than that of the first shaft portion.
Have,
The electric actuator according to claim 1 or 2, wherein the recessed portion is provided in the second shaft portion. The connecting portion has a tubular portion and has a tubular portion.
The electric actuator according to claim 3, further comprising a connecting recess in which the driven body is connected to the inner diameter of the cylinder portion. The electric actuator according to claim 3 or 4, wherein the motor shaft is supported by a third bearing at the second shaft portion. The motor unit has a stator facing the rotor in the radial direction through a gap.
The stator is
An annular stator core along the circumferential direction and
The insulator mounted on the stator core and
Have,
Any of claims 3 to 5, wherein the one end portion of the third bearing in the axial direction is located between the other end portion of the rotor in the axial direction and the other end portion of the insulator in the axial direction. The electric actuator according to one item. A deceleration mechanism connected to the other side of the motor shaft in the axial direction is provided.
The electric actuator according to any one of claims 1 to 6, wherein the output shaft is transmitted with the rotation of the motor shaft via the reduction mechanism.

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