WO2007116788A1

WO2007116788A1 - Electric actuator

Info

Publication number: WO2007116788A1
Application number: PCT/JP2007/056632
Authority: WO
Inventors: Takashi Watabe
Original assignee: Mikuni Corporation
Priority date: 2006-04-12
Filing date: 2007-03-28
Publication date: 2007-10-18
Also published as: JPWO2007116788A1

Abstract

An electric actuator capable of being assembled by a reduced number of man-hour to improve work efficiency. A housing (4) is made up of three members that are a gear housing (5), a drive-side cover (6), and a cap (7). The gear housing (5) has a first receiving space (11), a second receiving space (12), and a motor receiving space (13). A motor (1), on the output shaft (17) of which a worm (21) is provided, is received in the motor receiving space. A worm wheel (23) meshing with the worm and a spur gear (25) are received in the first receiving space. A spur gear (43) meshed with the spur gear (25) and an output shaft (2) integral with the spur gear (43) are received in the second receiving space are received. The drive-side cover is attached to the gear housing so as to close the openings of motor receiving space and the first receiving space. The cap (7) is attached to the gear housing to close the opening of the second receiving space with the output shaft (2) projected from the gear housing.

Description

Specification

Electric actuator

Technical field

TECHNICAL FIELD [0001] The present invention relates to an electric actuator having a reduction gear device that transmits rotational power of a motor to an output shaft, and operates an intake system valve such as a variable intake control valve, a swirl control valve, or a tumble generator valve. The present invention relates to an electric actuator.

Background art

Conventionally, for example, as such an electric actuator, a motor, a reduction gear device that transmits rotational power of the motor to an output shaft, and a cover case (housing) that covers the motor and the reduction gear device are provided. And a resin case is known which includes a case body having a substantially container shape in which a motor and a reduction gear device are housed, and a resin cover covering the opening of the case body (for example, Patent Document 1).

[0003] Patent Document 1: Japanese Patent No. 3449163

Disclosure of the invention

Problems to be solved by the invention

[0004] However, in such a conventional electric actuator, the motor and the reduction gear device are assembled from the opening side to the resin case body, and the resin cover is attached to the resin case body. It is necessary to assemble this member only from one side, and there is a problem that the work efficiency is poor due to many assembly processes.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide an electric actuator capable of reducing the number of assembling steps and improving the work efficiency. Means for solving the problem

[0006] In order to achieve the above object, an electric actuator according to claim 1 includes a motor, a reduction device that transmits rotational power of the motor to an output shaft, and a housing that covers the motor and the reduction device. An electric actuator comprising:

The housing includes a gear housing, a drive side cover, and an output side cover. Features.

[0007] In the invention described in claim 1, since the assembly of the member into the gear housing can be performed in parallel on both the drive side cover side and the output side cover side, the assembly man-hours Can be reduced and work efficiency can be improved.

[0008] 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 to different sides and is connected to the first storage space and the second storage space. A storage space, and a motor storage space that is formed on the same side as the first storage space and opens to the same side as the first storage space, and is connected to the first storage space on the opening side. The second storage space is an output-side storage space for storing the output shaft for transmitting the output from the motor and the speed reducer.

[0009] To assemble the electric actuator according to claim 2, the first storage space 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 space and the motor storage space, parts such as the speed reducer and motor are assembled and stored from the opening side, and in parallel, members such as the output shaft are installed on the opening side in the second storage space on the other side. Assemble the force and store it. 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.

[0010] In this way, according to the present invention, the assembly of members such as the motor, the reduction gear, and the output shaft can be performed in parallel from both sides of the gear housing, so that the number of assembly steps can be reduced. And work efficiency can be improved.

In addition, when manufacturing multiple types of electric actuators with different output shafts according to the requirements of the actuated side such as intake system valves, it can be easily handled by changing the assembly only on the second storage space side can do.

[0011] The electric actuator according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the speed reduction device is a speed reduction gear device.

[0012] In the invention described in claim 3, since the reduction gear device is used as the reduction device, reliable power transmission can be performed. [0013] 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 in which a first gear is provided on an output shaft of the motor storage space also assembles an opening side force. A second gear that is rotatably provided around the axis of the first storage space and meshed with the first gear of the motor; and The second storage space is provided so as to be rotatable about the axis of the first storage space, and is assembled with an opening-side force assembled with a third gear that rotates as the second gear rotates. Includes a fourth gear which is provided rotatably about the axis of the second storage space and meshed with the third gear, and is provided on the fourth gear. The output shaft that rotates as the motor rotates is housed in an opening-side force assembled, and is stored in the drive-side cover. 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.

[0014] To assemble the electric actuator according to claim 4, the first storage on one side of the first storage space (and the motor storage space) and the second storage space that open to different sides of the gear housing. The second gear, the third gear, the motor with the first gear, and the like are stored in the space and the motor storage space, respectively, while being assembled with the opening side force. Storing the 4th gear, output shaft, etc. with the opening side force assembled. Then, the drive side cover is attached to 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.

[0015] Thus, according to the present invention, since the assembly of the motor, the gear of the reduction gear device, etc. can be performed in parallel from both sides of the gear housing, the number of assembly steps can be reduced and the work can be reduced. Efficiency can be improved.

[0016] According to a fifth aspect of the present invention, there is provided the electric actuator according to the fourth aspect of the invention. The housing is provided with a detecting device for detecting the magnetic field of the magnet embedded in the fourth gear.

[0017] In the invention according to claim 5, since the gear housing is equipped with the detection device for detecting the magnetic field of the magnet embedded in the fourth gear, the magnet rotating with the fourth gear is provided. The magnetic field of the stone can be detected.

[0018] 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.

[0019] In the invention according to claim 6, since the reed switch is used as the detection device, a small size, light weight and low cost can be realized.

[0020] 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.

[0021] In the invention according to claim 7, the rotation angle sensor is used as the detection device.

The rotation angle of the magnet embedded in the gear 4, that is, the rotation angle of the output shaft can be detected.

[0022] In the electric actuator according to claim 8, in the invention according to any one of claims 4 to 8, the first gear is a worm, and 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 formed integrally with a spur gear that is the fourth gear.

[0023] In the invention according to claim 8, the reduction ratio can be increased, the gear space can be reduced, and reliable power transmission can be performed.

[0024] The electric actuator according to claim 9 is the invention according to claim 8, wherein the first

The worm that is the gear of 1 is characterized by being a double thread.

[0025] In the invention according to claim 9, the strength of the screw can be increased and the power can be reliably transmitted.

[0026] In the electric actuator according to claim 10, in the invention according to claim 8 or 9, 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. [0027] In the invention according to claim 10, since the gear housing and the output side cover are each provided with a bearing, and the output shaft is supported by these bearings at two points, the output shaft is stably provided. Power can be transmitted to the actuated side.

[0028] The electric actuator according to claim 11 is the invention according to any one of claims 8 to 10, wherein the output shaft is supported by a protrusion formed integrally with the gear housing. It is characterized by that.

[0029] In the invention according to claim 11, since the output shaft is supported by the protrusion formed integrally with the gear housing, it is not necessary to separately incorporate a member for supporting the output shaft. Therefore, the member and the assembly process can be omitted.

[0030] The electric actuator according to claim 12 is the invention according to any one of claims 8 to 11, wherein the second gear and the third gear are connected via a buffer member. Being featured!

[0031] In the invention according to claim 12, since the second gear and the third gear are connected via the buffer member, the biting of the gear can be reduced. This is especially effective in reducing the warm gear!

[0032] The electric actuator according to claim 13 is the invention according to any one of claims 8 to 12, wherein the second gear and the third gear are the second gear and the second gear. In addition, it is characterized in that both protrusions provided on the third gear rotate together by interposing a buffer member therebetween.

[0033] In the invention according to claim 13, since the protrusions of the second gear and the third gear are entangled with each other with the buffer member interposed therebetween, the second gear and the second gear The three gears can rotate reliably and can reduce the biting of the gears. It is particularly effective in reducing the worm gear bite and sticking.

[0034] The electric actuator according to claim 14 is the invention according to claim 13, in which one of the second gear and the third gear is on the outer peripheral side of the buffer member. And an overhanging portion is provided so as to extend to the other side of the second gear and the third gear from the buffer member, and a portion of the overhang portion ahead of the buffer member The other of the second gear and the third gear is snap-fit connected. It is characterized by that.

[0035] In the invention according to claim 14, 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 protruding portion, and Since the movement of the gear in the axial direction is also restricted by the snap-fit coupling at the tip of the protruding portion, it is possible to prevent the buffer member from falling off between the two protruding portions.

[0036] The electric actuator according to Claim 15 is the invention according to any one of Claims 1 to 14, wherein the gear housing, the drive side cover, and the output side cover are all formed of thermoplastic resin. The drive-side force bar and the output-side cover are each attached to the gear housing by ultrasonic welding.

[0037] In the invention according to claim 15, the drive side cover and the output side cover can be efficiently attached to the gear housing.

The invention's effect

[0038] 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.

Brief Description of Drawings

FIG. 1 is a perspective view showing an electric actuator according to an embodiment of the present invention.

FIG. 2 is a plan view.

FIG. 3 is a front view showing the state in which the drive side cover is removed.

4 is a cross-sectional view taken along the line AA in FIG.

FIG. 5 is a sectional view taken along line BB in FIG.

6 is a cross-sectional view taken along the line CC in FIG.

FIG. 7 is a perspective view showing a connecting portion between a worm wheel and a spur gear.

FIG. 8 is a cross-sectional view showing a connecting portion between a worm wheel and a spur gear.

Explanation of symbols

[0040] 1 motor 2 Output shaft

3 Reduction gear unit (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 Warm Hoi Nore (second gear)

25 Spur gear (third gear)

26 Protrusion

27 Protrusion

28 cushioning material

29 Overhang

41 Protrusion

42 Slide bearing (bearing)

43 Spur gear (4th gear)

47 Slide bearing (bearing)

BEST MODE FOR CARRYING OUT THE INVENTION

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 a cross-sectional view taken along line CC in FIG. Figure 7 shows the worm wheel and spar. FIG. 8 is a perspective view showing a connecting portion with a gear, and FIG. 8 is a cross-sectional view showing a connecting portion between a worm wheel and a spur gear.

[0042] The electric actuator includes a motor 1, a reduction gear device (reduction device) 3 that reduces the rotational power of the motor 1 and transmits it to the output shaft 2, and a housing that covers the motor 1 and the reduction gear device 3 4 and. 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 drive side cover 6, and a cap (output side cover) 7. These gear housing 5, the drive side cover 6 and the cap 7 are both thermoplastic resin. Consists of.

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 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 13 are connected. The opening of the storage space 11 is connected. A drive side storage space 14 is formed by the motor storage space 13 and the first storage space 11.

[0044] In the motor storage space 13, the motor 1 is stored. The motor 1 is also inserted into the motor housing space 13 by the opening side force, 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, a shaft 22 is provided in the first storage space 11 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 a thrust and a thrust acting on the worm wheel 23. A ball bearing (bearing) 24 capable of supporting a force in the radial direction is provided. Further, a spur gear (third gear) 25 is rotatably supported on the shaft 22 on the back side of the first storage space 11.

[0045] 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. That is, the worm wheel 23 is formed with a protrusion 26 protruding toward the spur gear 25, while the spar gear 25 is also formed with a protrusion 27 protruding toward the worm wheel 23. The portion 26 and the protrusion 27 are joined together with a cushioning member 28 made of a rubber or other elastic material, so that the spur gear 25 rotates integrally with the worm wheel 23 via the cushioning member 28. It is becoming like that.

[0046] The protrusion 26 of the worm wheel 23, the buffer member 28, and the protrusion 27 of the spur gear 25 have a cylindrical shape as a whole, and the spar gear 25 has a worm wheel 23 side so as to cover the outer periphery. A protruding 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 tip of the overhang 29 protrudes further toward the worm wheel 23 than the protrusion 26 of the worm wheel 23, the buffer member 28, and the protrusion 27 of the spur gear 25, and is located inside the tip of the overhang 29. Is formed with a protrusion 33 extending in the circumferential direction. 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-fitted by the protrusion 34 and the protrusion 33. This reliably prevents the buffer member 28 from falling off between the protrusion 26 of the worm wheel 23 and the protrusion 27 of the spur gear 25.

[0047] 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 openings of the space 13 and the first storage space 11 are closed. In this case, approximately half of the motor 1 and approximately half of the worm 21 and a part of the worm wheel 23 that are exposed to the outside from the inside of the motor storage space 13 and the first storage space 11 are inside the drive side cover 6. It is stored in. On the other hand, in the second storage space 12, a cylindrical protrusion (shaft portion) 41 protruding along the axis of the second storage space 12 is integrally formed with the gear housing 5 on the bottom surface. Is formed. A spur gear (fourth gear) 43 is supported on the protrusion 41 via a slide bearing (bearing) 42 having a flange at one end. More specifically, in the plain bearing 42 with the flange, the cylindrical portion is fitted to the outside of the protrusion 41 and the flange is in contact with the bottom surface of the second storage space 12, while the spur gear 43 A centered boss is formed with a bottomed cylindrical fitting hole 44, and the fitting hole 44 is rotatably fitted to the outside of the cylindrical portion of the slide bearing 42. The spur gear 43 is engaged 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 formed in a shape in which only the half other than the boss, which is not a regular circular one, is formed. A magnet 45 is embedded in one end of the spur gear 43. The worm 21, the worm wheel 23, the spur gear 25 and the spur gear 43 constitute the reduction gear device 3.

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 thereof protrudes from the second storage space 12 to the outside.

[0050] 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 move the axial direction of the second storage space 12 of the flange portion of the slide bearing 47, the spur gear 43 and the flange portion of the slide bearing 42. Is regulated. Further, the cap 7 is formed with a rotation stop 48 that protrudes in a fan shape in the direction of the force at the bottom of the storage space 12, and each end face in the circumferential direction of the spur gear 43 abuts against the rotation stop 48. Thus, the rotation range of the spur gear 43 is restricted, and thereby the rotation range of the output shaft 2 that rotates together with the spur gear 43 is restricted.

[0051] The gear housing 5 includes a terminal assembly 52 including a plurality of terminals 51. In addition, a reed switch 53 is provided. 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 attraction 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 sparger 43 rotates. The rotating operation of the magnet 45 generates a magnetic field and closes the contact of the reed switch 53 (becomes 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 at which the magnet 45 embedded in one end of the spur gear 43 is overlapped with the reed switch 53 by the rotation of the output shaft reaches the reed switch 53, the contact of the reed switch 53 is closed and current flows. In other words, the circuit is connected by turning ON / OFF the reed switch 53 and the current flows, whereby the rotation angle of the output shaft at a certain rotation angle can be detected. By using the present invention actuator, it is connected to the output shaft 2 and is not shown in the figure. The rotation angle of the operation shaft on the apparatus side is detected, and can be detected by the rotation angle. As a result, it is not necessary 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.

[0053] 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 (output-side storage space) 12 that open on opposite sides of the gear housing 5 is provided. In the drive-side storage space 14, the motor 1 and some of the gears (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 also assembled with the opening side force. While storing, in parallel with this, the output on the other side In the side storage space 12, 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 (spar gear 43 and Integrate the output shaft 2 with the opening side force and store it. Then, 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.

[0054] More specifically, first, the worm wheel 23 and the spur gear 25 are integrated in advance by snap-fit coupling in a state where the buffer member 28 is interposed between the projection 26 and the projection 27. Keep it.

Next, the shaft 22 is inserted into the integrated worm wheel 23 and 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, which 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 a 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 Secure to drive side storage space 14 with 16. At this time, the worm 21 is engaged with the worm wheel 23.

Next, the opening of the drive side cover 6 is brought into contact with the opening of the drive side storage space 14 of the gear housing 5 and attached by ultrasonic welding.

[0056] 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 in which the output shaft 2 is formed in a body, and a slide bearing 47 are arranged in this order. The second storage space 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 projection 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 sliding bearing 47 is also fitted. Is fitted to the outside of the base of the output shaft 2.

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. [0057] 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 1 outputs through the worm 21, the worm wheel 23, the sparger 25 and the spur gear 43. The rotational power of the motor 1 is transmitted to the shaft 2. 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.

[0058] In the electric actuator configured as described above, the assembly of the motor 1 and the gear of the reduction gear device 3 and the like can be performed in parallel from both sides of the gear housing 5, thus reducing the number of assembly steps. And work efficiency can be improved.

Also, when manufacturing multiple types of electric actuators incorporating different output shafts 2 according to the requirements of the actuated side such as intake system valves, only the assembly on the second storage space 12 side needs to be changed. Can be easily accommodated.

[0059] 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 and the gear space can be reduced. And reliable power transmission. Furthermore, since the worm 21 is a double thread screw, the strength of the screw can be increased and power can be transmitted reliably.

[0060] Further, since the output shaft 2 is supported at two points by the slide bearings 42 and 47 provided in the gear housing 5 and the cap 7, respectively, power is stably transmitted from the output shaft 2 to the operated side. it can.

In addition, since the output shaft 2 is supported by the protrusion 41 formed integrally with the gear housing 5, there is no need to separately install a member that supports the output shaft 2, and therefore, the member and the assembly process are omitted. Can do.

Further, 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. Therefore, the member and the assembly process can be omitted.

[0061] Further, since both the protrusions 26 and 27 of the worm wheel 23 and the spur gear 25 are interposed between the force buffer members 28, the worm wheel 23 and the spur gear 25 are reliably rotated integrally. And worm gear (worm 21 and worm wheel 23) The food can be relaxed.

Further, the spur gear 25 is provided with an overhanging portion 29 that protrudes to the outer peripheral side of the buffer member 28 and to the worm wheel 23 side of the buffer member 28, and ahead of the buffer member 28 of the overhang portion 29. The worm wheel 23 and the worm wheel 23 are snap-fit connected, so the buffer member 28 interposed between the projections 26 and 27 of the worm wheel 23 and the spur gear 25 regulates the movement toward the outer periphery side by the overhanging portion 28. At the same time, the snap fit coupling of the tip of the overhanging portion 28 restricts the movement of the gear in the axial direction, so that it is possible to prevent the buffer member 28 from falling off between the protrusions 26 and 27. it can

[0062] Further, since the gear housing 5, the drive side cover 6 and the cap 7 are both formed of thermoplastic resin, and the drive side cover and the cap 7 are respectively attached to the gear housing 5 by ultrasonic welding, Installation of drive side cover 6 and cap 7 to gear housing 5 can be performed efficiently.

[0063] In the above-described embodiment, the output side storage space (second storage space) 12 and the drive side storage space 14 (the motor storage space 13 and the first storage space 11) are opposite to each other. 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.

[0064] Not limited to the above-described embodiment, various types of gears can be used as the reduction gear device 3.

In the above-described embodiment, the output shaft 2 may be a force-separated body formed integrally with the spur gear 43.

In the above-described embodiment, the overhanging portion 29 is provided on the spur gear 25 side, but the overhanging portion may be provided on the warm wheel 23 side!

Claims

The scope of the claims

[1] An electric actuator comprising 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, and the housing is driven with a gear housing. An electric actuator characterized by comprising a side cover and an output side cover.

[2] The gear housing is formed on the same side as the first storage space and the first storage space and the second storage space that are open to different sides and connected to each other. A motor storage space that opens to the same side as the storage space and is connected to the first storage space on the opening side, and the second storage space includes the motor and the speed reducer. 2. The electric actuator according to claim 1, wherein the electric actuator is an output-side storage space for storing the output shaft for transmitting the output from the motor.

[3] The electric actuator according to claim 1 or 2, wherein the reduction gear is a reduction gear device.

[4] 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 axis of the first storage space is stored in the first storage space. A second gear meshed with the first gear of the motor, and a second gear geared about the axis of the first storage space. A third gear that rotates with the rotation of the first gear, and is housed by being assembled with an opening-side force, and the second storage space is provided so as to be rotatable about the axis of the second storage space. A fourth gear that meshes with the third gear and the output shaft that is provided in the fourth gear and that rotates as the fourth gear rotates is assembled and stored with the opening side force assembled. The drive side cover is disposed in the gear housing in the motor storage space and the first storage space. The output-side cover is attached to the gear housing so that the output shaft protrudes and closes the opening of the second storage space. The electric actuator according to claim 3.

5. 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.

6. The electric actuator according to claim 5, wherein the detection device is a reed switch.

7. 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.

[8] 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 first gear. The electric actuator according to any one of claims 4 to 7, wherein the electric actuator is formed integrally with a spur gear which is a gear of 4.

9. The electric actuator according to claim 8, wherein the worm as the first gear is a double thread.

10. 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.

[11] The electric actuator according to any one of claims 8 and 10, wherein the output shaft is supported by a protrusion formed integrally with the gear housing.

[12] The electric actuator according to any one of claims 8 and 11, wherein the second gear and the third gear are connected via a buffer member. .

[13] The second gear and the third gear are integrated with each other 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 rotating.

[14] One of the second gear and the third gear is provided on the outer peripheral side of the buffer member and on the other side of the second gear and the third gear with respect to the buffer member. A projecting portion is provided, and a portion of the projecting portion ahead of the buffer member and the other of the second gear and the third gear are snap-fit coupled, The electric actuator according to claim 13.

[15] The gear housing, the drive-side cover, and the output-side cover are all formed of thermoplastic resin, and the drive-side cover and the output cover are formed on the gear housing. The force side covers are attached by ultrasonic welding, respectively.

1. The electric actuator according to claim 14.