JPWO2007116788A1 - Electric actuator - Google Patents

Abstract

Provided is an electric actuator that can reduce assembly man-hours and improve work efficiency.
The housing 4 includes three members, a gear housing 5, a drive side cover 6, and a cap 7, and the gear housing 5 includes a first storage space 11, a second storage space 12, and a motor storage space 13. In the motor storage space, the motor 1 having the output shaft 17 provided with the worm 21 is stored. In the first storage space, the worm wheel 23 and the spur gear 25 that mesh with the worm are stored, and the second storage space is stored. In the storage space, a spur gear 43 meshed with the spur gear 25 and the output shaft 2 integrated with the spur gear 43 are stored, and the drive-side cover has a motor housing space and a first storage space in the gear housing. The cap 7 is attached so as to close the opening, and the cap 7 is attached so as to close the opening of the second storage space by causing the output shaft 2 to protrude from the gear housing. .

Description

  The present invention relates to an electric actuator incorporating a reduction gear device that transmits rotational power of a motor to an output shaft, and is an electric actuator for operating an intake system valve such as a variable intake control valve, a swirl control valve, or a tumble generator valve. It relates to an actuator.

  Conventionally, for example, such an electric actuator includes a motor, a reduction gear device that transmits rotational power of the motor to an output shaft, and a resin case (housing) that covers the motor and the reduction gear device, and A known resin case includes a case body having a substantially container shape that houses a motor and a reduction gear device, and a resin cover that closes an opening of the case body (see, for example, Patent Document 1).

Japanese Patent No. 3449163

  However, in such a conventional electric actuator, since the motor and the reduction gear device are assembled to the resin case main body from the opening side and the resin cover is attached to the resin case main body, all the members are assembled from one side. There is a problem that there are many assembly processes and work efficiency is poor.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric actuator that can reduce assembly man-hours and can improve work efficiency.

In order to achieve the object, an electric actuator according to claim 1 includes a motor, a reduction gear that transmits rotational power of the motor to an output shaft, and a housing that covers the motor and the reduction gear. An electric actuator,
The housing includes a gear housing, a drive side cover, and an output side cover.

  In the invention according to claim 1, since the assembly of the member into the gear housing can be performed in parallel from both the drive side cover side and the output side cover side, the assembly man-hour can be reduced, and the work efficiency can be reduced. Can be improved.

  According to a second aspect of the present invention, there is provided the electric actuator according to the first aspect, wherein the gear housing opens on different sides and is connected to the first storage space and the second storage space. A motor storage space formed on the same side as the first storage space and opening on the same side as the first storage space and connected to the first storage space on the opening side; The second storage space is an output-side storage space that stores the output shaft that transmits the output from the motor and the speed reducer.

  To assemble the electric actuator according to claim 2, the first storage space and the motor on one side of the first storage space (and the motor storage space) and the second storage space opened on different sides of the gear housing. In the storage space, the members such as the speed reducer and the motor are assembled and stored from the opening side, and in parallel, the members such as the output shaft are assembled and stored in the second storage space on the other side from the opening side. . Then, the drive side cover is attached to the opening of the motor housing space and the first housing space of the gear housing, and the output side cover is attached to the opening of the second housing space.

As described above, in the present invention, since the assembly of the members such as the motor, the reduction gear, and the output shaft can be performed in parallel from both sides of the gear housing, the number of assembling steps can be reduced and the working efficiency can be improved. .
In addition, when a plurality of types of electric actuators with different output shafts are manufactured according to the requirements of the operated side such as an intake system valve, it is easily handled by changing the assembly only on the second storage space side. be able to.

  According to a third aspect of the present invention, in the electric actuator according to the first or second aspect, the speed reduction device is a speed reduction gear device.

  In the invention described in claim 3, since the reduction gear device is used as the reduction gear, reliable power transmission can be performed.

  According to a fourth aspect of the present invention, in the electric actuator according to the third aspect, in the motor storage space, a motor having a first gear provided on an output shaft thereof is assembled and stored from the opening side, The first storage space is provided so as to be rotatable about the axis of the first storage space, and is engaged with the first gear of the motor, and the first storage space. And a third gear which is provided so as to be rotatable about the axis of the second gear and which rotates with the rotation of the second gear. The third gear is assembled and stored from the opening side, and the second storage space includes the second gear. A fourth gear which is provided to be rotatable about the axis of the storage space and is engaged with the third gear, and is provided on the fourth gear and rotates with the rotation of the fourth gear. The output shaft is assembled and stored from the opening side, and the drive side The bar is attached to the gear housing so as to close the openings of the motor storage space and the first storage space, and the output-side cover projects the output shaft from the gear housing. It is attached so that the opening part of 2 storage space may be obstruct | occluded.

  To assemble the electric actuator according to claim 4, the first storage space and the motor on one side of the first storage space (and the motor storage space) and the second storage space opened on different sides of the gear housing. The second gear, the third gear, the first geared motor, and the like are assembled and stored in the storage space from the opening side, and in parallel, the second gear is stored in the second storage space on the other side. The gear, output shaft, etc. are assembled and stored from the opening side. Then, the drive side cover is attached to the opening of the motor housing space and the first housing space of the gear housing, and the output side cover is attached to the opening of the second housing space.

As described above, in the present invention, since the motor and the gears of the reduction gear device can be assembled in parallel from both sides of the gear housing, the number of assembling steps can be reduced and the working efficiency can be improved.
In addition, when a plurality of types of electric actuators with different output shafts are manufactured according to the requirements of the operated side such as an intake system valve, it is easily handled by changing the assembly only on the second storage space side. be able to.

  According to a fifth aspect of the present invention, in the electric actuator according to the fourth aspect, the gear housing is provided with a detection device for detecting a magnetic field of a magnet embedded in the fourth gear. Features.

  In the fifth aspect of the invention, since the gear housing is equipped with a detection device for detecting the magnetic field of the magnet embedded in the fourth gear, the magnetic field of the magnet rotating with the fourth gear is detected. can do.

  According to a sixth aspect of the present invention, in the electric actuator according to the fifth aspect, the detection device is a reed switch.

  In the invention described in claim 6, since the reed switch is used as the detection device, it is possible to realize a small size, light weight and low cost.

  According to a seventh aspect of the present invention, in the electric actuator according to the fifth aspect, the detection device is a rotation angle sensor that detects a rotation angle of the output shaft.

  In the invention described in claim 7, since the rotation angle sensor is used as the detection device, the rotation angle of the magnet embedded in the fourth gear, that is, the rotation angle of the output shaft can be detected.

  An electric actuator according to an eighth aspect of the present invention is the electric actuator according to any one of the fourth to eighth aspects, wherein the first gear is a worm, the second gear is a worm wheel, and the third gear. The spur gear is a spur gear, the fourth gear is a spur gear, and the output shaft is integrally formed with the spur gear that is the fourth gear.

  In the invention according to claim 8, the reduction ratio can be increased, the space of the gear can be reduced, and reliable power transmission can be performed.

  According to a ninth aspect of the present invention, in the electric actuator according to the eighth aspect, the worm that is the first gear is a double thread.

  In invention of Claim 9, while being able to raise the intensity | strength of a screw, power can be transmitted reliably.

  According to a tenth aspect of the present invention, in the electric actuator according to the eighth or ninth aspect, the output shaft is supported at two points by bearings respectively provided on the gear housing and the output side cover. It is characterized by.

  In the invention according to claim 10, since the gear housing and the output side cover are respectively provided with bearings and the output shaft is supported at two points by these bearings, the power is stably supplied from the output shaft to the operated side. Can communicate.

  According to an eleventh aspect of the present invention, in the electric actuator according to any one of the eighth to tenth aspects, the output shaft is supported by a protrusion formed integrally with the gear housing. And

  In the eleventh aspect of the invention, since the output shaft is supported by the protrusion formed integrally with the gear housing, it is not necessary to separately incorporate a member that supports the output shaft, and therefore the member and the assembling process are omitted. can do.

  According to a twelfth aspect of the present invention, in the electric actuator according to any one of the eighth to eleventh aspects, the second gear and the third gear are connected via a buffer member. It is characterized by that.

  In the twelfth aspect of the invention, since the second gear and the third gear are connected via the buffer member, the biting of the gear can be reduced. This is particularly effective in reducing biting of the worm gear.

  The electric actuator according to a thirteenth aspect is the invention according to any one of the eighth to twelfth aspects, wherein the second gear and the third gear are the second gear and the third gear. The projections provided on the gear are integrally rotated by meshing with each other through a buffer member.

  In the invention described in claim 13, since the projections of the second gear and the third gear are engaged with each other with the buffer member interposed therebetween, the second gear and the third gear are surely connected. While rotating integrally, gear biting can be reduced. This is particularly effective in reducing biting of the worm gear.

  The electric actuator according to a fourteenth aspect is the invention according to the thirteenth aspect, wherein either one of the second gear and the third gear is provided on the outer peripheral side of the buffer member and the buffer member. In addition, there is provided an overhanging portion that extends to the other side of the second gear and the third gear, and a portion of the overhanging portion ahead of the buffer member, the second gear, and the second gear. The other of the three gears is snap-fit connected.

  In the invention according to the fourteenth aspect, the buffer member interposed between the protrusions of the second gear and the third gear is restricted from moving to the outer peripheral side by the projecting portion, and the tip of the projecting portion. Since the movement of the gear in the axial direction is also restricted by the snap-fit coupling of this portion, it is possible to prevent the buffer member from falling off between the two protrusions.

  An electric actuator according to a fifteenth aspect is the invention according to any one of the first to fourteenth aspects, wherein the gear housing, the drive side cover, and the output side cover are all formed of a thermoplastic resin. The drive-side cover and the output-side cover are each attached to the gear housing by ultrasonic welding.

  According to the fifteenth aspect of the present invention, it is possible to efficiently mount the drive side cover and the output side cover to the gear housing.

  According to the electric actuator of the present invention, the assembly of the member to the gear housing can be performed in parallel at two locations, so that the number of assembling steps can be reduced and the working efficiency can be improved.

It is a figure which shows the electric actuator which concerns on embodiment of this invention, Comprising: It is a perspective view. FIG. It is a front view of the state which removed the drive side cover similarly. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG. It is sectional drawing which follows the CC line of FIG. It is a perspective view which shows the connection part of a worm wheel and a spur gear. It is sectional drawing which shows the connection part of a worm wheel and a spur gear.

Explanation of symbols

1 Motor 2 Output shaft 3 Reduction gear device (reduction gear)
4 Housing 5 Gear housing 6 Drive side cover 7 Cap (output side cover)
11 First storage space 12 Second storage space (output-side storage space)
13 Motor storage space 14 Drive side storage space 17 Motor output shaft 21 Worm (first gear)
23 Worm wheel (second gear)
25 Spur gear (third gear)
26 Protruding part 27 Protruding part 28 Buffering member 29 Overhanging part 41 Protruding part 42 Slide bearing (bearing)
43 Spur gear (fourth gear)
47 Slide bearing (bearing)

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 8 are views showing an electric actuator according to an embodiment of the present invention. FIG. 1 is a perspective view, FIG. 2 is a plan view, and FIG. 3 is a state in which a drive side cover is removed. 4 is a cross-sectional view taken along line AA in FIG. 3, FIG. 5 is a cross-sectional view taken along line BB in FIG. 3, and FIG. 6 is taken along line CC in FIG. FIG. 7 is a perspective view showing a connecting portion between the worm wheel and the spur gear, and FIG. 8 is a cross-sectional view showing a connecting portion between the worm wheel and the spur gear.

  This electric actuator includes a motor 1, a reduction gear device (reduction device) 3 that decelerates the rotational power of the motor 1 and transmits it to the output shaft 2, and a housing 4 that covers the motor 1 and the reduction gear device 3. I have. The motor 1 is a DC motor that can rotate forward and reverse. The housing 4 is composed of three members: a gear housing 5, a driving side cover 6, and a cap (output side cover) 7. These gear housing 5, driving side cover 6 and cap 7 are all made of a thermoplastic resin. .

  The gear housing 5 includes a bottomed cylindrical first storage space 11 and a second storage space (output-side storage space) 12 extending in parallel with each other. The first storage space 11 and the second storage space 12 open to the opposite sides and are connected to each other at the bottom. On the same side as the first storage space 11, a motor storage space 13 is formed adjacent to the first storage space 11. The motor storage space 13 opens to the same side as the first storage space 11 and is connected to the first storage space 11 on the opening side. Therefore, the opening of the motor storage space 13 and the first storage space are connected. 11 openings are connected. A drive-side storage space 14 is formed by the motor storage space 13 and the first storage space 11.

The motor 1 is stored in the motor storage space 13. The motor 1 is inserted into the motor storage space 13 from the opening side and is sandwiched between the gear housing 5 and the drive side cover 6. The motor 1 is electrically connected to a terminal 51 described later by a plurality of joint plates 16. A double thread worm (first gear) 21 is fixed to the output shaft 17 of the motor 1. A cap member 19 is fixed to the joint plate 16 side of the motor 1, and the cap member 19 supports a thrust force acting on the output shaft 17 of the motor 1.
On the other hand, the first storage space 11 is provided with a shaft 22 along the axis of the first storage space 11. One end of the shaft 22 is supported by a recess at the bottom of the first storage space 11, and the other end is supported by a recess inside the drive side cover 6. A worm wheel (second gear) 23 that meshes with the worm 21 is rotatably supported on the shaft 22. Between the worm wheel 23 and the shaft 22, there is provided a ball bearing (bearing) 24 capable of supporting thrust acting on the worm wheel 23 and a radial force. Further, a spur gear (third gear) 25 is rotatably supported on the shaft 22 on the back side of the first storage space 11.

  The spur gear 25 is connected to the worm wheel 23, and rotates as the worm wheel 23 rotates. The worm wheel 23 and the spur gear 25 are connected as follows. In other words, the worm wheel 23 is formed with projections 26 projecting toward the spur gear 25, while the spar gear 25 is also formed with projections 27 projecting toward the worm wheel 23, and these projections 26 And the protrusion 27 are engaged with each other with a buffer member 28 made of an elastic material such as rubber interposed therebetween, whereby the spur gear 25 rotates integrally with the worm wheel 23 via the buffer member 28. .

  The protrusion 26 of the worm wheel 23, the buffer member 28, and the protrusion 27 of the spur gear 25 are formed in a cylindrical shape as a whole, and the spar gear 25 has a circle protruding toward the worm wheel 23 so as to cover the outer periphery. An annular projecting portion 29 is formed. In this projecting portion, two narrow linear notches 31 are formed at opposite positions in the circumferential direction. The protruding portion 29 protrudes toward the worm wheel 23 from the protruding portion 26 of the worm wheel 23, the buffer member 28, and the protruding portion 27 of the spur gear 25. A projecting portion 33 extending in the direction is formed. Further, the worm wheel 23 is formed with a protrusion 34 extending in the circumferential direction, and the spur gear 25 and the worm wheel 23 are snap-fit coupled by the protrusion 34 and the protrusion 33. This reliably prevents the buffer member 28 from falling off between the projection 26 of the worm wheel 23 and the projection 27 of the spur gear 25.

  The opening of the drive-side cover 6 is abutted with the opening of the motor housing space 13 and the first housing space 11 of the gear housing 5 and is attached by ultrasonic welding. The opening of one storage space 11 is closed. In this case, approximately half of the motor 1, approximately half of the worm 21, and a part of the worm wheel 23, which are exposed to the outside from the inside of the motor storage space 13 and the first storage space 11, are part of the drive side cover 6. It is stored.

On the other hand, in the second storage space 12, a cylindrical projection (shaft portion) 41 that protrudes along the axis of the second storage space 12 is formed integrally with the gear housing 5 on the bottom surface. . A spur gear (fourth gear) 43 is supported on the projection 41 via a slide bearing (bearing) 42 having a flange at one end. More specifically, in the sliding bearing 42 with a flange, the cylindrical portion is fitted to the outside of the protruding portion 41 and the flange portion is in contact with the bottom surface of the second storage space 12. A bottomed cylindrical fitting hole 44 is formed in the central boss, and the fitting hole 44 is rotatably fitted to the outside of the cylindrical portion of the slide bearing 42. The spur gear 43 meshes with the spur gear 25 through a portion (space) where the bottom of the second storage space 12 and the bottom of the first storage space 11 are connected. The spur gear 43 is not an ordinary circular shape, and a portion other than the boss is formed in a half shape. A magnet 45 is embedded in one end of the spur gear 43.
The reduction gear device 3 is configured by the worm 21, the worm wheel 23, the spur gear 25, and the spur gear 43.

  In the spur gear 43, the output shaft 2 is formed integrally with the spur gear 43 at the center of the side surface on the opening side of the second storage space 12. The output shaft 2 extends along the axis of the second storage space 12, and a tip portion of the output shaft 2 protrudes from the second storage space 12 to the outside.

  A cap 7 is fitted into the opening of the second storage space 12 and is attached by ultrasonic welding, whereby the opening of the second storage space 12 is closed. A through hole 46 is formed in the center of the cap 7, and the base of the output shaft 2 is supported in the through hole 46 via a slide bearing (bearing) 47 having a flange at one end. ing. More than half of the output shaft 2 protrudes outward from the cap 7. In addition, the inner surface of the cap 7 and the bottom surface of the second storage space 12 restrict the movement of the flange portion of the slide bearing 47, the spur gear 43, and the flange portion of the slide bearing 42 in the axial direction of the second storage space 12. ing. Further, the cap 7 is formed with a rotation stop 48 that protrudes in a fan shape in the direction toward the bottom of the storage space 12, and each end face in the circumferential direction of the spur gear 43 abuts on the rotation stop 48, thereby Thus, the rotation range of the output shaft 2 that rotates integrally with the spur gear 43 is restricted.

The gear housing 5 is provided with a terminal assembly 52 having a plurality of terminals 51 and a reed switch 53. The terminal 51 is provided with a motor side terminal connected to the motor 1 and a reed switch side terminal connected to the reed switch 53.
A sleeve 63 is press-fitted into the mounting hole of the mounting flange 61 of the gear housing 5.

Here, the reed switch 53 will be described. The reed switch 53 is a small and lightweight non-contact switch, and is operated by the magnetic attractive force of the magnet 45 embedded in one end of the spur gear 43. A magnet 45 is embedded in one end of the spur gear 43, and the magnet 45 also rotates as the spur gear 43 rotates. A magnetic field is generated by the rotating operation of the magnet 45, and the contact of the reed switch 53 is closed (turned on).
The reed switch 53 is a sensor installed to detect the rotation angle of the output shaft at a certain rotation angle. When the rotation angle of the magnet 45 embedded in one end portion of the spur gear 43 reaches the rotation angle overlapping the reed switch 53 due to the rotation of the output shaft, the contact of the reed switch 53 is closed and a current flows. That is, the rotation of the output shaft at a certain rotation angle can be detected by connecting the circuit by turning on and off the reed switch 53 and causing a current to flow. By using the proposed actuator, it is possible to detect the rotation angle of the operation shaft on the apparatus side (not shown) that is locked to the output shaft 2 and co-operates with the output shaft 2 at a rotation angle that is desired to be detected. As a result, there is no need to provide an angle sensor for detecting the rotation angle on the apparatus side, and the apparatus can be reduced in size, cost, and simplicity.
The reed switch 53 is a sensor for detecting the rotation angle of the output shaft at a certain rotation angle as described above, but a rotation angle sensor that outputs the rotation angle may be used as the detection device.

This electric actuator is assembled as follows.
That is, one of the drive side storage space 14 (the first storage space 11 and the motor storage space 13) and the second storage space (the output side storage space) 12 that open to opposite sides of the gear housing 5 is driven. In the side storage space 14, the motor 1 and a part of the gear (the worm 21, the worm wheel 23, and the spur gear 25) constituting the reduction gear device 3 that is rotationally driven by the motor 1 are assembled and stored from the opening side. In parallel with this, the remaining gear (spur gear 43) constituting the reduction gear device 3 and the last gear (spar gear 43) constituting the reduction gear device 3 are rotated in the output-side storage space 12 on the other side. Accordingly, the output shaft 2 (integrated with the spur gear 43) that rotates with the rotation is assembled and stored from the opening side. The drive-side cover 6 is attached to the opening of the drive-side storage space 14 of the gear housing 5, and the cap (output-side cover) 7 is attached to the opening of the second storage space 12.

More specifically, first, the worm wheel 23 and the spur gear 25 are integrated in advance by snap-fit coupling in a state in which the buffer member 28 is interposed between the projection 26 and the projection 27.
Next, the shaft 22 is inserted into the integrated worm wheel 23 and the spur gear 25, and the ball bearing 24 is mounted between the shaft 22 and the worm wheel 23.
Next, the worm wheel 23, the spur gear 25, the shaft 22, and the ball bearing 24 that are in such an integrated state are placed in the first storage space 11 of the drive-side storage space 14 of the gear housing 5. Inserting from the opening side of the first storage space 11, one end of the shaft 22 is inserted into the recess at the bottom of the first storage space 11.

Next, the motor 1 with the worm 21 fixed to the output shaft 17 is inserted into the motor storage space 13 of the drive side storage space 14 from the opening side of the drive side storage space 14, and the joint plate 16 drives the drive side. Fix in the storage space 14. At this time, the worm 21 is engaged with the worm wheel 23.
Next, the opening of the drive-side cover 6 abuts the opening of the drive-side storage space 14 of the gear housing 5 and is attached by ultrasonic welding.

On the other hand, in the second storage space (output-side storage space) 12 of the gear housing 5, a slide bearing 42, a spur gear 43 integrally formed with the output shaft 2 and a slide bearing 47 are arranged in this order. 12 is inserted from the opening side. At this time, the cylindrical portion of the slide bearing 42 is fitted to the outside of the protrusion 41, the fitting hole 44 of the spur gear 43 is fitted to the outside of the cylindrical portion of the slide bearing 42, and the slide bearing 47 is connected to the output shaft 2. It is fitted on the outside of the base.
Next, the cap 7 is fitted into the opening of the second housing space 12 of the gear housing 5 and attached by ultrasonic welding. At this time, the through hole 46 of the cap 7 is fitted to the outside of the cylindrical portion of the slide bearing 47.

  In such an electric actuator, when the motor 1 is energized and the motor 1 operates and the motor 1 rotates forward or backward, the motor is applied to the output shaft 2 via the worm 21, the worm wheel 23, the spur gear 25 and the spur gear 43. 1 rotational power is transmitted. At this time, the rotational speed of the output shaft 2 is greatly reduced with respect to the rotational speed of the motor 1. The output shaft 2 operates an intake system valve and the like.

In the electric actuator configured as described above, the motor 1 and the gears of the reduction gear device 3 can be assembled in parallel from both sides of the gear housing 5, so that the number of assembling steps can be reduced and the work efficiency can be reduced. Can be improved.
Further, when manufacturing a plurality of types of electric actuators incorporating different output shafts 2 according to the requirements of the operated side such as the intake system valve, only the assembly of the second storage space 12 side is changed. It can be easily handled.

  In addition, since the reduction gear device 3 using the worm gear (worm 21 and worm wheel 23) and the spur gears 25 and 43 is used, the reduction ratio can be increased, the gear space can be reduced, and reliable. Power transmission can be performed. Furthermore, since the worm 21 is a double thread, the strength of the screw can be increased and power can be transmitted reliably.

Further, since the output shaft 2 is supported at two points by the slide bearings 42 and 47 provided on the gear housing 5 and the cap 7, power can be stably transmitted from the output shaft 2 to the operated side.
Further, since the output shaft 2 is supported by the protrusion 41 formed integrally with the gear housing 5, it is not necessary to separately incorporate a member that supports the output shaft 2, and thus the member and the assembling process can be omitted. .
Furthermore, since the rotation stopper 48 for restricting the rotation range of the output shaft 2 is formed on the cap 7, it is not necessary to separately install the rotation stopper, so that the member and the assembly process can be omitted.

Further, since both the protrusions 26 and 27 of the worm wheel 23 and the spur gear 25 are engaged with each other with the buffer member 28 interposed therebetween, the worm wheel 23 and the spur gear 25 are reliably rotated integrally, and the worm gear (worm 21 and the worm wheel 23) can be reduced.
Further, the spur gear 25 is provided with an overhanging portion 29 that protrudes to the worm wheel 23 side of the buffer member 28 on the outer peripheral side of the buffer member 28, and a portion of the overhang portion 29 ahead of the buffer member 28. Since the worm wheel 23 and the worm wheel 23 are snap-fit coupled, the buffer member 28 interposed between the projections 26 and 27 of the worm wheel 23 and the spur gear 25 is restricted by the protruding portion 28 from moving toward the outer peripheral side. At the same time, since the movement of the gear in the axial direction is also restricted by the snap-fit coupling of the tip portion of the overhanging portion 28, it is possible to prevent the buffer member 28 from falling off between the two protruding portions 26 and 27.

  The gear housing 5, the drive side cover 6 and the cap 7 are all formed of thermoplastic resin, and the drive side cover and the cap 7 are attached to the gear housing 5 by ultrasonic welding. The work of attaching the cap 7 to the gear housing 5 can be performed efficiently.

  In the above-described embodiment, the output-side storage space (second storage space) 12 and the drive-side storage space 14 (motor storage space 13 and first storage space 11) are opened to the opposite sides. However, instead of this, the output side storage space and the drive side storage space may be opened on different sides such as an oblique direction and a right angle direction.

Further, the present invention is not limited to the embodiment described above, and various gears can be used as the reduction gear device 3.
In the above-described embodiment, the output shaft 2 is formed integrally with the spur gear 43, but may be a separate body.
In the above-described embodiment, the overhang portion 29 is provided on the spur gear 25 side, but the overhang portion may be provided on the worm wheel 23 side.

Claims (15)

  An electric actuator comprising a motor, a reduction gear that transmits the rotational power of the motor to an output shaft, and a housing that covers the motor and the reduction gear, the housing including a gear housing, a drive-side cover, and an output An electric actuator comprising a side cover.   The gear housing is formed on the same side as the first storage space and the first storage space and the first storage space that are open to different sides and connected to each other, and the first storage space A motor storage space that opens to the same side and is connected to the first storage space on the opening side, and the second storage space transmits the output from the motor and the speed reducer. The electric actuator according to claim 1, wherein the electric actuator is an output-side storage space for storing an output shaft.   The electric actuator according to claim 1, wherein the reduction device is a reduction gear device.   In the motor storage space, a motor having a first gear on its output shaft is assembled and stored from the opening side, and the first storage space is centered on the axis of the first storage space. A second gear that is rotatably provided and meshed with the first gear of the motor, and a second gear that is rotatable about the axis of the first storage space, and that rotates the second gear. A third gear that rotates with the second gear is assembled and stored from the opening side. The second gear is provided in the second gear space so as to be rotatable about the axis of the second gear space. A fourth gear meshed with the first gear and the output shaft provided in the fourth gear and rotating as the fourth gear rotates. The side cover is mounted on the gear housing in the motor storage space and the first storage. The output cover is attached to the gear housing so as to close the opening of the second storage space, and is attached to close the opening of the space. The electric actuator according to claim 3.   The electric actuator according to claim 4, wherein the gear housing is provided with a detection device for detecting a magnetic field of a magnet embedded in the fourth gear.   The electric actuator according to claim 5, wherein the detection device is a reed switch.   The electric actuator according to claim 5, wherein the detection device is a rotation angle sensor that detects a rotation angle of the output shaft.   The first gear is a worm, the second gear is a worm wheel, the third gear is a spur gear, the fourth gear is a spur gear, and the output shaft is the fourth gear. The electric actuator according to any one of claims 4 to 7, wherein the electric actuator is formed integrally with a spur gear.   The electric actuator according to claim 8, wherein the worm as the first gear is a double thread.   The electric actuator according to claim 8 or 9, wherein the output shaft is supported at two points by bearings respectively provided on the gear housing and the output side cover.   The electric actuator according to any one of claims 8 to 10, wherein the output shaft is supported by a protrusion formed integrally with the gear housing.   The electric actuator according to any one of claims 8 to 11, wherein the second gear and the third gear are connected with a buffer member interposed therebetween.   The second gear and the third gear rotate integrally by engaging both protrusions provided on the second gear and the third gear with a buffer member interposed therebetween. The electric actuator according to any one of claims 7 to 12, wherein the electric actuator is provided.   One of the second gear and the third gear projects to the outer peripheral side of the buffer member and to the other side of the second gear and the third gear from the buffer member. An overhanging portion is provided, and a portion of the overhanging portion ahead of the buffer member is snap-fitted to the other of the second gear and the third gear. Item 14. The electric actuator according to Item 13.   The gear housing, the driving side cover, and the output side cover are all formed of thermoplastic resin, and the driving side cover and the output side cover are respectively attached to the gear housing by ultrasonic welding. The electric actuator according to any one of claims 1 to 14.

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