JP2017187050A - Electrically-driven actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an output part to be driven linearly by a motor while restricting its large-sized formation.SOLUTION: There are provided a motor having a motor shaft extending in an axial direction; an electromagnetic brake for braking a rotation of the motor shaft under non-electrical energized state; a speed reducing mechanism connected to the motor shaft; a rotating part to which a rotation of the motor shaft is transmitted through the speed reducing mechanism; and a movable member moved in an axial direction as the rotating part is rotated. The rotating part has a helical first helical groove. The movable member comprises a main body part having a first helical groove and a helical second helical groove opposing against the first helical groove through a clearance and an output part contacted to a driving force transmitted part. A ball screw is configured by several spherical balls positioned in and among the first helical groove, the second helical groove, and the first helical groove and the second helical groove. The motor shaft and the rotating part are cylindrical in shape and at least a part of the rotating part is arranged inside the motor shaft and at least a part of the main body part is arranged inside the rotating part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electric actuator.

  2. Description of the Related Art Conventionally, an apparatus for switching a vehicle clutch or the like is known. For example, in the clutch operating device of Patent Document 1, a screw is rotated by an electric motor, and a nut block that is screw-coupled to the screw linearly moves, whereby the operating rod moves linearly. Thereby, the clutch is switched.

JP 2012-112515 A

  However, the apparatus as described above has a problem that the efficiency of converting the rotation of the screw into the linear movement of the nut block is relatively low. Due to this problem, in order to obtain a force sufficient to move the actuating rod linearly, it is necessary to enlarge the electric motor and increase the rotational torque transmitted to the screw. Therefore, there is a problem that the entire apparatus becomes large.

  In view of the above problems, an aspect of the present invention has an object to provide an electric actuator that can linearly drive an output unit with a motor while suppressing an increase in size.

  One aspect of the electric actuator of the present invention is an electric actuator that transmits a force to the driven force transmission portion, and includes a motor having a motor shaft extending in the axial direction, and rotation of the motor shaft in a non-energized state. An electromagnetic brake for braking, a speed reduction mechanism coupled to the motor shaft, a rotating portion to which the rotation of the motor shaft is transmitted via the speed reducing mechanism, and a movable that moves in the axial direction along with the rotation of the rotating portion And the rotating part has a spiral first spiral groove, and the movable member has a spiral second spiral groove facing the first spiral groove through a gap. A main body portion having an output portion that contacts the driven transmission portion, and the first spiral groove, the second spiral groove, and the first spiral groove and the second spiral groove. Multiple spherical located between A ball screw is configured by a tool, the motor shaft and the rotating part are cylindrical, at least a part of the rotating part is disposed inside the motor shaft, and at least a part of the main body part is It arrange | positions inside the said rotation part.

  According to one aspect of the present invention, there is provided an electric actuator capable of linearly driving an output unit by a motor while suppressing an increase in size.

FIG. 1 is a cross-sectional view showing the electric actuator of the present embodiment. FIG. 2 is a 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 view showing the electric actuator of the present embodiment and is a cross-sectional view taken along line III-III in FIG.

  Hereinafter, an electric actuator according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the electric actuator 10 attached to the vehicle body of the vehicle and switching the clutch mechanism C of the vehicle will be described as an example of the electric actuator.

  In the following description, the direction parallel to the first central axis J1 shown in FIG. 1 (the left-right direction in FIG. 1) may be simply referred to as “axial direction”, and the radial direction centered on the first central axis J1 is referred to as “axial direction”. In some cases, it is simply called “radial direction”, and the circumferential direction around the first central axis J1 is simply called “circumferential direction”. In addition, in the axial direction, the side (left side in FIG. 1) on which the input side power shaft S1 is disposed with respect to the output side power shaft S2 may be referred to as “front side (one side in the axial direction)”. The side where the output side power shaft S2 is arranged (the right side in FIG. 1) is sometimes referred to as “rear side (the other side in the axial direction)” with reference to S1. The front side and the rear side do not indicate the positional relationship when the electric actuator 10 is actually incorporated into the device.

  As shown in FIG. 1, the clutch mechanism C switches between disconnection and connection of two power shafts extending in the axial direction, that is, the input power shaft S1 and the output power shaft S2. FIG. 1 shows a state where the input-side power shaft S1 and the output-side power shaft S2 are disconnected. The input side power shaft S1 and the output side power shaft S2 are centered on the first central axis J1.

  The input-side power shaft S1 includes a shaft main body S1a extending in the axial direction, and a cylindrical portion S1b connected to the front end of the shaft main body S1a. The shaft body S1a is supported by the bearing B1 so as to be rotatable around the first central axis J1. The cylindrical portion S1b has a cylindrical shape that opens to the front side. A gear portion is provided on the inner peripheral surface of the cylindrical portion S1b.

  The output side power shaft S2 includes a shaft main body S2a extending in the axial direction and a sun gear portion S2b extending in the radial direction from the shaft main body S2a. The front end portion of the shaft body S2a is supported by a bearing B2 held by the cylindrical portion S1b. A gear portion is provided on the outer peripheral surface of the sun gear portion S2b.

  A plurality of planetary gears PG are arranged between the radial directions of the sun gear portion S2b and the cylindrical portion S1b. The planetary gear PG meshes with both the gear portion of the sun gear portion S2b and the gear portion of the cylindrical portion S1b. In this way, the input-side power shaft S1 and the output-side power shaft S2 are rotatably connected to each other via the bearing B2 and the planetary gear PG in a disconnected state.

  The clutch mechanism C includes a driven transmission portion C1 and a connecting member C2. The driven transmission portion C <b> 1 is disposed so as to be movable in the axial direction and is driven in the axial direction by the electric actuator 10. The driven force transmission portion C1 includes an annular plate-like disc portion C1a that extends in the radial direction, a cylindrical portion C1b that extends rearward from the outer edge of the disc portion C1a, and a rear end portion of the cylindrical portion C1b. And a protruding portion C1c extending inward in the radial direction. The output side power shaft S2 is passed through the radially inner side of the disc portion C1a.

  The connecting member C2 is located on the front side of the driven force transmission portion C1. The connecting member C2 has an annular plate shape. The output side power shaft S2 is passed through the inside of the connecting member C2 in the radial direction. The connecting member C2 is connected to the driven transmission portion C1 via bearings B3 and B4 so as to be rotatable around the input side power shaft S1 and the output side power shaft S2, that is, around the first central axis J1. .

  The connecting member C2 moves in the axial direction together with the driven transmission portion C1 when a force is applied to the driven transmission portion C1 from an output portion 52 (to be described later) of the electric actuator 10, and thus two power shafts, that is, input side power. It contacts both the shaft S1 and the output-side power shaft S2, and connects the two power shafts.

  The electric actuator 10 transmits force to the driven force transmission part C1. The electric actuator 10 includes a motor housing 11, a motor 20 having a motor shaft 21 extending in the axial direction, an electromagnetic brake 30, a speed reduction mechanism 40, a rotating portion 41, a movable member 50, and a plurality of spherical balls 60. And comprising.

  The motor housing 11 houses the motor 20 and the electromagnetic brake 30 therein. The motor housing 11 includes a cylindrical tube portion 11a extending in the axial direction around the first central axis J1, a front lid portion 11b provided at the front end of the tube portion 11a, and a rear side of the tube portion 11a. And a rear lid portion 11c provided at the end portion. Through holes are provided in the center of the front lid portion 11b and the center of the rear lid portion 11c, respectively.

  The motor 20 is fixed to the inner peripheral surface of the cylindrical portion 11a. The motor 20 includes a stator 24, a rotor core 22, a rotor magnet 23, and a motor shaft 21. The motor shaft 21 is disposed on the radially inner side of the stator 24. The motor shaft 21 is cylindrical. More specifically, the motor shaft 21 has a cylindrical shape with the first central axis J1 as the center and opening at both ends in the axial direction.

  The rear end portion of the motor shaft 21 protrudes rearward from the motor housing 11 through the through hole of the rear lid portion 11c. The motor shaft 21 is rotatably supported around the first central axis J1 by a bearing 78 disposed in a through hole of the front lid portion 11b and a bearing 76 provided in an internal gear 43 described later.

  The rear end portion of the motor shaft 21 is an eccentric portion 21a that is eccentric with respect to the first central axis J1. As shown in FIG. 2, the second central axis J2 passes through the center of the eccentric portion 21a. The second central axis J2 is an axis parallel to the first central axis J1 and different from the first central axis J1. In FIG. 2, the second central axis J2 is located above the first central axis J1.

  The electromagnetic brake 30 shown in FIG. 1 brakes the rotation of the motor shaft 21 in a non-conduction state. The electromagnetic brake 30 is disposed at a position that overlaps the motor shaft 21, the rotating portion 41, and a main body portion 51 described later in the radial direction. The electromagnetic brake 30 includes a first brake member 31, a second brake member 32, an adsorption member 33, an elastic member 35, and a solenoid 34.

  The first brake member 31 has an annular shape. The first brake member 31 is attached to the motor shaft 21 through which the motor shaft 21 is passed. The first brake member 31 is prevented from rotating in the circumferential direction with respect to the motor shaft 21, and rotates around the first central axis J <b> 1 together with the rotation of the motor shaft 21. The first brake member 31 is attached to the motor shaft 21 so as to be movable in the axial direction.

  The second brake member 32 has an annular plate shape. The second brake member 32 is fixed to the rear lid portion 11c with a screw. The second brake member 32 faces the first brake member 31 on the front side of the first brake member 31. The motor shaft 21 is passed inside the second brake member 32.

  It is preferable that the friction coefficient when the first brake member 31 and the second brake member 32 contact each other is relatively large. This is because the rotation of the motor shaft 21 can be suitably braked by the electromagnetic brake 30.

  The adsorbing member 33 has an annular plate shape. The motor shaft 21 is passed inside the adsorption member 33. The suction member 33 faces the first brake member 31 on the rear side of the first brake member 31. Accordingly, the first brake member 31 is disposed so as to be sandwiched between the second brake member 32 and the suction member 33 in the axial direction. The adsorption member 33 is disposed so as to be movable in the axial direction. The attracting member 33 is made of a magnetic material.

  The solenoid 34 is disposed on the rear side of the attracting member 33 so as to surround the radially outer side of the motor shaft 21. The solenoid 34 excites the attracting member 33. The solenoid 34 has a yoke 34a and a coil 34b.

  The yoke 34 a has an annular shape that surrounds the radially outer side of the motor shaft 21. The yoke 34a is fixed to the front surface of the rear lid portion 11c. The yoke 34a is made of a magnetic material. The coil 34b is disposed in a recessed portion that is provided on the front surface of the yoke 34a and that is recessed toward the rear side. The coil 34b is configured by winding a conducting wire in the circumferential direction.

  The elastic member 35 is, for example, a compression coil spring that extends in the axial direction. The elastic member 35 is disposed in a concave portion recessed on the rear side provided on the front surface of the yoke 34a. The elastic member 35 is located radially outside the coil 34b, and a plurality of elastic members 35 are provided along the circumferential direction. The rear end of the elastic member 35 is in contact with the bottom surface of the recess provided in the yoke 34a. The front end of the elastic member 35 is in contact with the rear surface of the adsorption member 33. The elastic member 35 applies a force toward the front side with respect to the adsorption member 33.

  When a current is supplied to the coil 34b, the yoke 34a and the attracting member 33 are excited by the magnetic field generated from the coil 34b. As a result, a magnetic circuit through which the magnetic flux passes through the yoke 34 a and the attracting member 33 is generated, and the attracting member 33 is attracted to the solenoid 34. In other words, the attracting member 33 is attracted to the solenoid 34 in the energized state where current is supplied to the solenoid 34. At this time, the magnetic force (attraction force) by the magnetic circuit between the yoke 34 a and the adsorption member 33 is larger than the forward elastic force applied to the adsorption member 33 by the elastic member 35.

  When the supply of current to the coil 34b is stopped, the magnetic circuit between the yoke 34a and the attracting member 33 is not generated, and the magnetic force (attracting force) between the yoke 34a and the attracting member 33 disappears. Thereby, the attracting member 33 moves away from the solenoid 34 and moves forward due to the forward elastic force of the elastic member 35. That is, in the non-energized state in which the supply of current to the solenoid 34 is stopped, the attracting member 33 is positioned away from the solenoid 34 to the front side.

  The suction member 33 is pushed by the elastic member 35 and moves, thereby contacting the first brake member 31 from the rear side and moving the first brake member 31 to the front side. As a result, the front surface of the first brake member 31 is pressed against the rear surface of the second brake member 32. That is, the first brake member 31 is pressed against the second brake member 32 by applying a force from the elastic member 35 toward the front side via the adsorption member 33. Thereby, the frictional force between the first brake member 31 and the second brake member 32 prevents the first brake member 31 from rotating in the circumferential direction, and the rotation of the motor shaft 21 in the circumferential direction is suppressed. . Thus, the electromagnetic brake 30 brakes the rotation of the motor shaft 21 in a non-energized state.

  According to this configuration, the braking operation of the motor shaft 21 by the electromagnetic brake 30 can be switched only by switching the supply of current to the solenoid 34. Therefore, the braking operation of the motor shaft 21 is simple. Further, since the rotation of the motor shaft 21 can be braked in a non-energized state, the movement of the movable member 50 can be braked without supplying current to either the motor 20 or the solenoid 34. Therefore, the power consumption of the electric actuator 10 can be reduced.

  In the present embodiment, the first brake member 31 is movable in the axial direction. Therefore, the braking state of the motor shaft 21 by the electromagnetic brake 30 can be switched by moving the first brake member 31 by the adsorption member 33 while the axial position of the motor shaft 21 is fixed.

  FIG. 1 shows a non-energized state in which the supply of current to the solenoid 34 is stopped. When current is supplied to the solenoid 34, the attracting member 33 moves rearward from the position shown in FIG. 1 and is attracted to the solenoid 34.

  The speed reduction mechanism 40 is connected to the motor shaft 21. More specifically, the speed reduction mechanism 40 is connected to the rear end portion of the motor shaft 21 via a bearing 70. The speed reduction mechanism 40 includes an external gear 42, an internal gear 43, and a connection portion 44.

  The external gear 42 has a substantially annular plate shape that extends in a plane orthogonal to the axial direction. As shown in FIG. 2, the second central axis J <b> 2 is passed through the center of the external gear 42. That is, the external gear 42 is centered on the central axis of the motor shaft 21, that is, the axis that is eccentric with respect to the first central axis J1 in this embodiment.

  A gear portion is provided on the radially outer surface of the external gear 42. As shown in FIGS. 1 and 2, the external gear 42 is connected to the motor shaft 21 via a bearing 70. The external gear 42 is fitted to the outer ring of the bearing 70 from the outside in the radial direction. Thereby, the bearing 70 connects the motor shaft 21 and the external gear 42 so as to be relatively rotatable around the second central axis J2.

  The external gear 42 has a hole 42a that penetrates the external gear 42 in the axial direction. As shown in FIG. 2, a plurality of holes 42 a are provided and are arranged at equal intervals along the circumferential direction with the second central axis J <b> 2 as the center. In FIG. 2, eight holes 42a are provided, for example. The shape viewed along the axial direction of the hole 42a is circular. The inner diameter of the hole 42a is larger than the outer diameter of the pin 44a described later.

  The internal gear 43 is fixed so as to surround the outer side in the radial direction of the external gear 42 and meshes with the external gear 42. As shown in FIG. 1, the internal gear 43 includes a fixed portion 43 a and an internal gear main body 43 b.

  The fixed portion 43a has an annular shape that extends in the radial direction about the first central axis J1. The fixed portion 43 a is disposed on the front side of the external gear 42. The fixing portion 43a is fixed to the rear surface of the rear lid portion 11c. The outer ring of the bearing 76 is fixed to the inner side surface of the fixing portion 43a. The fixed portion 43 a supports the motor shaft 21 via the bearing 76.

  The internal gear main body 43b protrudes rearward from the radial outer edge of the fixed portion 43a. As shown in FIGS. 1 and 2, the internal gear main body 43b has an annular shape centered on the first central axis J1. The internal gear main body 43 b surrounds the outer side of the external gear 42 in the radial direction. A gear portion is provided on the inner peripheral surface of the internal gear main body 43b. The gear portion of the internal gear main body 43 b meshes with the gear portion of the external gear 42. More specifically, as shown in FIG. 2, the gear portion of the internal gear main body 43b meshes with the gear portion of the external gear 42 in part (upper portion in FIG. 2).

  As shown in FIG. 1, the connection portion 44 is disposed on the rear side of the external gear 42. The connecting portion 44 has an annular plate shape that extends in the radial direction about the first central axis J1. The connection unit 44 is connected to the rotation unit 41. More specifically, the connecting portion 44 extends radially outward from the rear end portion of the rotating portion 41. In this embodiment, the connection part 44 and the rotation part 41 are parts of a single member. Therefore, the number of parts and assembly man-hours of the electric actuator 10 can be reduced. The rotation of the motor shaft 21 is transmitted to the rotation unit 41 via the speed reduction mechanism 40.

  The connection part 44 has a plurality of pins 44a. The pin 44a has a columnar shape protruding to the front side. As shown in FIG. 2, the plurality of pins 44a are arranged at equal intervals along the circumferential direction. As shown in FIGS. 1 and 2, the plurality of pins 44 a are respectively passed through the plurality of holes 42 a provided in the external gear 42. The outer peripheral surface of the pin 44a is inscribed with the inner peripheral surface of the hole 42a. The pin 44a supports the external gear 42 so as to be swingable around the second central axis J2.

  When the motor shaft 21 is rotated around the first central axis J1, the eccentric portion 21a (second central axis J2) revolves in the circumferential direction around the first central axis J1. The revolution of the eccentric portion 21a is transmitted to the external gear 42 via the bearing 70, and the external gear 42 swings while the inscribed position between the inner peripheral surface of the hole 42a and the outer peripheral surface of the pin 44a is changed. . As a result, the position where the gear portion of the external gear 42 and the gear portion of the internal gear 43 mesh with each other changes in the circumferential direction. Therefore, the rotational force of the motor shaft 21 is transmitted to the internal gear 43 via the external gear 42.

  Here, in this embodiment, since the internal gear 43 is fixed, it does not rotate. Therefore, the external gear 42 rotates around the second central axis J2 by the reaction force of the rotational force transmitted to the internal gear 43. At this time, the rotating direction of the external gear 42 is opposite to the rotating direction of the motor shaft 21. The rotation of the external gear 42 around the second central axis J2 is transmitted to the connection portion 44 through the hole 42a and the pin 44a. As a result, the connecting portion 44 rotates about the first central axis J1, and the rotating portion 41 rotates about the first central axis J1.

  The rotation of the rotating unit 41 is decelerated with respect to the rotation of the motor shaft 21 by the reduction mechanism 40. Specifically, in the configuration of the speed reduction mechanism 40 of the present embodiment, the reduction ratio R of the rotation of the rotating portion 41 with respect to the rotation of the motor shaft 21 is represented by R = − (N2−N1) / N2. The negative sign at the head of the expression representing the reduction ratio R indicates that the rotation direction of the rotating portion 41 that is decelerated is opposite to the rotation direction of the motor shaft 21. N1 is the number of teeth of the external gear 42, and N2 is the number of teeth of the internal gear 43. As an example, when the number of teeth N1 of the external gear 42 is 59 and the number of teeth N2 of the internal gear 43 is 60, the reduction ratio R is −1/60.

  Thus, according to the speed reduction mechanism 40 of the present embodiment, the reduction ratio R of the rotation of the rotating portion 41 with respect to the rotation of the motor shaft 21 can be made relatively large. Therefore, the rotational torque of the rotating part 41 can be relatively increased, and the output of the movable member 50 can be increased.

  The rotating part 41 is cylindrical. More specifically, the rotating part 41 is a cylindrical hollow shaft that extends in the axial direction about the first central axis J1. At least a part of the rotating part 41 is disposed inside the motor shaft 21. In FIG. 1, the whole except for the rear end portion of the rotating portion 41 is disposed inside the motor shaft 21.

  The rotating part 41 opens at both axial ends. The rear end of the rotating part 41 is supported by a bearing 71 fixed to the inner surface of the eccentric part 21a so as to be rotatable around the first central axis J1. The front end portion of the rotating portion 41 is supported by a bearing 77 fixed to the inner surface at the front end of the motor shaft 21 so as to be rotatable around the first central axis J1. The rotating part 41 has a first spiral groove 41a. The first spiral groove 41 a is a spiral groove located on the inner peripheral surface of the rotating portion 41.

  The movable member 50 has a main body portion 51 and an output portion 52. The main body 51 has a cylindrical shape that extends in the axial direction and opens on both sides in the axial direction. More specifically, the main body 51 is cylindrical with the first central axis J1 as the center. At least a part of the main body 51 is disposed inside the rotating part 41. In FIG. 1, the main body portion 51 is disposed inside the rotating portion 41 except for ends on both sides in the axial direction of the main body portion 51.

  The main body 51 has a second spiral groove 51a. The second spiral groove 51 a is a spiral groove located on the outer peripheral surface of the main body 51. The second spiral groove 51a is opposed to the first spiral groove 41a in the radial direction through a gap. A plurality of spherical balls 60 are located between the first spiral groove 41a and the second spiral groove 51a.

  A ball screw 90 is configured by the first spiral groove 41 a, the second spiral groove 51 a, and the plurality of balls 60. Thereby, the movable member 50 is connected to the rotating unit 41 and moves in the axial direction as the rotating unit 41 rotates.

  Since the connecting portion between the rotating portion 41 and the movable member 50 is the ball screw 90, the frictional force between the rotating portion 41 and the movable member 50 can be reduced. Thereby, the rotational torque of the motor 20 can be efficiently converted into the driving force in the axial direction of the movable member 50. Therefore, even when the rotational torque of the motor 20 is relatively small, it is possible to sufficiently obtain the axial driving force transmitted to the driven power transmission portion C1 via the output portion 52. Thereby, the motor 20 can be reduced in size, and as a result, the electric actuator 10 can be reduced in size.

  Moreover, since the frictional force between the rotation part 41 and the movable member 50 can be made small, it can suppress that the 1st spiral groove 41a and the 2nd spiral groove 51a are worn out by friction. Therefore, it can suppress that the connection part of the rotation part 41 and the movable member 50 wears out, and can improve the durability of the electric actuator 10 as a result.

  Moreover, since the rotational torque of the motor 20 can be made relatively small, the energy consumption of the motor 20 can be reduced.

  In the ball screw 90, the plurality of balls 60 pass through a spiral path 90a in which a first spiral groove 41a and a second spiral groove 51a are opposed to each other. In the spiral passage 90a, the plurality of balls 60 are in contact with the inner surface of the first spiral groove 41a and the inner surface of the second spiral groove 51a. The plurality of balls 60 move in the circumferential direction along the spiral passage 90a while rolling. The rotation of the rotating portion 41 can be converted into the movement of the movable member 50 in the axial direction by moving the spiral passage 90a while the plurality of balls 60 roll.

  The ball screw 90 has, for example, a ball circulation unit (not shown). The ball circulation part is provided in the main body part 51. The ball circulation portion is a passage that connects both ends of the spiral passage 90a. The ball 60 that has reached one end of the spiral passage 90a passes through the ball circulation section and moves to the other end of the spiral passage 90a. Thereby, the ball 60 can circulate in the spiral passage 90a.

  In the present specification, the ball screw is not limited to the ball screw having the above-described configuration, and may be any known ball screw.

  Further, as described above, at least a part of the rotating part 41 is arranged inside the motor shaft 21, and at least a part of the main body part 51 is arranged inside the rotating part 41. Therefore, the axial dimension of the electric actuator 10 can be reduced by arranging at least a part of each part in the radial direction, and the electric actuator 10 can be further downsized.

  The motor shaft 21, the rotating part 41, and the main body part 51 are at least partially overlapped with each other in the radial direction. Therefore, the axial dimension of the electric actuator 10 can be further reduced.

  Further, as described above, the electromagnetic brake 30 is disposed at a position overlapping the motor shaft 21, the rotating portion 41, and the main body portion 51 in the radial direction. Therefore, in addition to the motor shaft 21, the rotating part 41, and the main body part 51, the electromagnetic brake 30 is also arranged so as to overlap in the radial direction, whereby the axial dimension of the electric actuator 10 can be further reduced.

  Further, as described above, the main body 51 has a cylindrical shape that opens on both sides in the axial direction. Therefore, a part of the device on which the electric actuator 10 is mounted can be accommodated inside the main body 51. Thereby, the installation area | region of the electric actuator 10 can be made small in the apparatus in which the electric actuator 10 is mounted.

  In the present embodiment, one of the two power shafts that can be switched between disconnection and connection by the clutch mechanism C, that is, the output-side power shaft S2 in FIG. Therefore, the space inside the main body 51 can be effectively used as a space through which the output-side power shaft S2 passes. Thereby, the installation area | region of the electric actuator 10 in a vehicle body can be made small.

  The output part 52 is a part that comes into contact with the driven transmission part C1. The output unit 52 is connected to the front end of the main body 51. That is, the side where the output part 52 is connected to the main body part 51 and the side where the speed reduction mechanism 40 is connected to the motor shaft 21 are opposite to each other.

  The output part 52 includes a disk part 52 a and an output elastic part 53. As shown in FIGS. 1 and 3, the disc part 52 a has an annular plate shape that extends radially outward from the front end part of the main body part 51. The first central axis J1 passes through the center of the disc part 52a. The disc part 52a is arrange | positioned at the radial inside of the cylindrical part C1b. The outer edge portion of the rear surface of the disc portion 52a faces the front surface of the protrusion C1c in the axial direction. The disc part 52a has a recess 52b that is recessed from the front surface to the rear side. As shown in FIG. 3, the shape seen along the axial direction of the recess 52b is a circular shape. A plurality (six in FIG. 3) of the recesses 52b are provided along the circumferential direction.

  As shown in FIG. 1, the output elastic portions 53 are respectively disposed in the recesses 52b. The output elastic portion 53 has a truncated cone shape that decreases in outer diameter and inner diameter from the rear side toward the front side. The front end portion of the output elastic portion 53 protrudes to the front side with respect to the recess 52b. The output elastic part 53 faces the rear surface of the disk part C1a in the axial direction.

  When the movable member 50 moves to the front side from the state shown in FIG. 1, the output elastic portion 53 contacts the driven transmission portion C1 from the rear side and pushes the driven transmission portion C1 forward. Thereby, the power transmission part C1 moves to the front side. When the driven transmission part C1 moves to the front side, the connecting member C2 connected to the driven transmission part C1 also moves to the front side. The connecting member C2 comes into contact with the tubular portion S1b of the input side power shaft S1 and the sun gear portion S2b of the output side power shaft S2 from the rear side. Thereby, the input side power shaft S1 and the output side power shaft S2 are connected by the output part 52 via the connecting member C2.

  When pushing the driven transmission part C1 forward, the output elastic part 53 receives a reaction force backward from the driven transmission part C1, and elastically deforms in the axial direction. Therefore, for example, even when the movement of the movable member 50 in the axial direction is stopped, the elastic force corresponding to the elastic deformation of the output elastic portion 53 is continuously applied to the driven transmission portion C1 via the output portion 52. Can do. In the present embodiment, the output unit 52 applies a forward elastic force to the driven force transmission unit C1. Thereby, the state of the clutch mechanism C can be maintained, and the state where the input-side power shaft S1 and the output-side power shaft S2 are connected can be maintained.

  Here, as described above, according to the present embodiment, even when no current is supplied to the motor 20 and the electromagnetic brake 30, the rotation of the motor shaft 21 can be braked by the electromagnetic brake 30, and the axis of the movable member 50 can be reduced. Directional movement can be braked. Therefore, the movable member 50 can be stopped without supplying current to the motor 20 and the electromagnetic brake 30, and a force can be continuously applied to the driven force transmission portion C1. As a result, the electric actuator 10 can save power.

  In this specification, “the output elastic portion is elastically deformed in the axial direction” means that the elastic force applied to the driven force transmission portion C1 by the elastically deformed output elastic portion includes an axial component. Including elastic deformation of the part.

  With the above configuration, according to the present embodiment, an energy-saving and highly efficient small and lightweight electric actuator 10 can be obtained.

  The present invention is not limited to the above-described embodiment, and other configurations can be employed.

  The configuration of the speed reduction mechanism 40 is not particularly limited. For example, the movable member 50 and the internal gear 43 are configured as a single member, and the rotation is transmitted to the movable member 50 by the rotation of the internal gear 43. It may be configured. In this case, the pin 44a is fixed to the rear lid portion 11c, for example.

  Moreover, the structure which directly connects the power transmission part C1 with the input side power shaft S1 and the output side power shaft S2 may be sufficient. That is, it is possible to employ a configuration in which the driven transmission portion C1 is a portion that constitutes at least a part of the clutch mechanism C.

  Further, the driven force transmission portion C1 is not particularly limited, and may be a portion other than the clutch mechanism C in the vehicle, or may be a portion such as a device and a product other than the vehicle.

  Each structure of the said embodiment can be suitably combined in the range which does not contradict each other.

  DESCRIPTION OF SYMBOLS 10 ... Electric actuator, 20 ... Motor, 21 ... Motor shaft, 30 ... Electromagnetic brake, 31 ... 1st brake member, 32 ... 2nd brake member, 33 ... Adsorption member, 34 ... Solenoid, 35 ... Elastic member, 40 ... Deceleration Mechanism: 41 ... Rotating part, 41a ... First spiral groove, 42 ... External gear, 42a ... Hole, 43 ... Internal gear, 44 ... Connection part, 44a ... Pin, 50 ... Movable member, 51 ... Body part, 51a ... 2nd spiral groove, 52 ... output part, 53 ... output elastic part, 60 ... ball, 90 ... ball screw, C ... clutch mechanism, C1 ... driven transmission part, C2 ... connecting member, S1 ... input side power shaft (Power shaft), S2 ... Output side power shaft (Power shaft)

Claims (9)

An electric actuator that transmits force to a driven transmission part,
A motor having a motor shaft extending in the axial direction;
An electromagnetic brake for braking the rotation of the motor shaft in a non-energized state;
A speed reduction mechanism coupled to the motor shaft;
A rotating part to which rotation of the motor shaft is transmitted via the speed reduction mechanism;
A movable member that moves in the axial direction along with the rotation of the rotating part;
With
The rotating part has a spiral first spiral groove,
The movable member is
A main body having a spiral second spiral groove facing the first spiral groove via a gap;
An output unit in contact with the driven transmission unit;
Have
A ball screw is configured by the first spiral groove, the second spiral groove, and a plurality of spherical balls positioned between the first spiral groove and the second spiral groove,
The motor shaft and the rotating part are cylindrical,
At least a part of the rotating part is disposed inside the motor shaft,
An electric actuator in which at least a part of the main body is disposed inside the rotating part. The deceleration mechanism is
An external gear that is connected to the motor shaft via a bearing and that is centered on an axis that is eccentric with respect to the central axis of the motor shaft;
An internal gear fixed around the radial outer side of the external gear and meshed with the external gear;
A plurality of pins respectively passed through a plurality of holes provided in the external gear, and a connection portion connected to the rotating portion;
The electric actuator according to claim 1, comprising:   The electric actuator according to claim 1, wherein the motor shaft, the rotating part, and the main body part overlap each other in the radial direction at least in part.   The electric actuator according to any one of claims 1 to 3, wherein the main body has a cylindrical shape that opens to both sides in the axial direction. The driven transmission part is a part constituting at least a part of a clutch mechanism for switching between disconnection and connection of two power shafts extending in the axial direction,
The electric actuator according to claim 4, wherein one of the power shafts is passed through the inside of the main body. The clutch mechanism includes the driven transmission portion arranged to be movable in the axial direction, and a connecting member connected to the driven transmission portion so as to be rotatable around the axis of the power shaft. ,
When a force is applied from the output part to the driven transmission part, the connecting member moves in the axial direction together with the driven transmission part and contacts both of the two power shafts. The electric actuator according to claim 5, wherein the shaft is connected.   The electric actuator according to claim 1, wherein the output unit includes an output elastic unit that elastically deforms in an axial direction.   The electric actuator according to any one of claims 1 to 7, wherein the electromagnetic brake is disposed at a position overlapping with the motor shaft, the rotating portion, and the main body portion in a radial direction. The electromagnetic brake is
A first brake member attached to the motor shaft;
A second brake member facing the first brake member on one axial side of the first brake member;
An adsorption member made of a magnetic material facing the first brake member on the other side in the axial direction of the first brake member and arranged to be movable in the axial direction;
An elastic member that applies a force toward one side in the axial direction with respect to the adsorption member;
A solenoid that surrounds the radially outer side of the motor shaft on the other side in the axial direction of the adsorption member, and energizes the adsorption member;
Have
In the energized state in which current is supplied to the solenoid, the adsorption member is adsorbed by the solenoid,
In the non-energized state in which the supply of current to the solenoid is stopped, the suction member is located away from the solenoid on one side in the axial direction, and the first brake member is interposed through the suction member. The electric actuator according to any one of claims 1 to 8, wherein a force is applied from an elastic member toward one side in an axial direction and is pressed against the second brake member.

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