WO2021075217A1 - Electric actuator - Google Patents

Abstract

An electric actuator provided with: an electric motor 2; a speed reducer 3 that reduces the rotation of the electric motor 2 and outputs the same; a screw shaft 7 that is rotated by the output from the speed reducer 3; a bearing 9 supporting the screw shaft 7 in a rotatable manner; and a housing accommodating the electric motor 2, the speed reducer 3, the screw shaft 7, and the bearing 9. The electric motor 2, the speed reducer 3, and the bearing 9 are coupled to each other by means of mating parts 16b, 26a, 26b, and 18f, which restrict radial movement between the electric motor 2, the speed reducer 3, and the bearing 9.

Description

Electric actuator

The present invention relates to an electric actuator.

In recent years, electric motors have been promoted in order to save labor and reduce fuel consumption of vehicles. For example, a system for operating an automatic transmission, a brake, a steering wheel, etc. of an automobile by the power of an electric motor has been developed and put on the market. ..

As an electric actuator used for such an application, for example, in Patent Document 1 below, an electric actuator including a speed reducer that decelerates and outputs the rotation of an electric motor, a motion conversion mechanism that converts a rotary motion into a linear motion, and the like. Is described. This electric actuator includes a pair of housing splits, and components of each mechanical element such as an electric motor, a speed reducer, and a sliding screw mechanism are held so as to be sandwiched between the pair of housing splits. ..

JP-A-2019-97352

By the way, in the electric actuator described in Patent Document 1, when assembling each component to the housing, if components such as an electric motor, a speed reducer, and a sliding screw mechanism are temporarily assembled from each other and tried to be housed in the housing. Since the components are not fixed to each other, the relative positions of the components may shift or separate during assembly.

Even if each component is assembled to the housing, if the housing and the component are made of different materials, the gap between the housing and the component is large due to the difference in expansion coefficient in a high temperature environment. As a result, there is a concern that the housing cannot maintain the relative positions of the components with high accuracy.

As described above, the configuration described in Patent Document 1 has problems in the assembling property of the component parts to the housing and the accuracy of the relative position holding.

Therefore, an object of the present invention is to provide an electric actuator capable of improving assembling property and relative position holding accuracy.

In order to solve the above problems, the present invention includes an electric motor, a speed reducer that reduces and outputs the rotation of the electric motor, a screw shaft that rotates by the output of the speed reducer, and a bearing that rotatably supports the screw shaft. An electric actuator comprising an electric motor, a speed reducer, a screw shaft and a housing for accommodating a bearing, the electric motor, the speed reducer and the bearing via a fitting portion that regulates radial movement between them. Provide what is linked.

In this way, the electric motor, the speed reducer, and the bearing are connected via a fitting portion that regulates the radial movement between them, so that when they are assembled in the housing, they are radially connected to each other. It is possible to prevent misalignment and separation, which facilitates assembly work. Further, even after the assembly is completed, the electric motor, the speed reducer, and the bearing can be prevented from being displaced in the radial direction, so that their relative positions can be maintained with high accuracy.

It is preferable that the electric motor, the reduction gear and the bearing are fixed by a fixing member so as not to be separated in the axial direction.

By fixing the electric motor, reduction gear and bearing so as not to separate in the axial direction in this way, it becomes easier to assemble these to the housing. In addition, the relative position retention after assembly becomes stronger.

The electric actuator may include a motor holder that holds the electric motor, a speed reducer housing that constitutes the exterior portion of the speed reducer, and a bearing holder that holds the bearing. In this case, the motor holder, the speed reducer housing, and the bearing holder are connected via a fitting portion that regulates radial movement, so that the motor holder, the speed reducer, and the bearing are relatively assembling property. The position holding accuracy can be improved.

The speed reducer includes an input rotating body to which a driving force is input, an orbital ring arranged on the outer periphery of the input rotating body, and a plurality of planetary rotating bodies that revolve while rotating between the input rotating body and the orbital ring. It may be a planetary reducer having an output rotating body that rotates with the revolving motion of the planetary rotating body. Further, the track ring may also serve as a speed reducer housing having the fitting portion.

Further, when the speed reducer is a planetary speed reducer as described above, the screw shaft is movably connected to the output rotating body in the axial direction, so that the screw is screwed even if an axial force is generated on the screw shaft. By moving the shaft in the axial direction with respect to the output rotating body, it is possible to suppress the application of the axial force to the planetary rotating body of the speed reducer or the like. This makes it possible to prevent the risk of damage to the planetary rotating body and the like.

According to the present invention, it becomes possible to improve the assembling property of the component parts to the housing and the relative position holding accuracy.

It is a perspective view of the electric actuator which concerns on one Embodiment of this invention. It is a vertical sectional view of an electric actuator. It is sectional drawing in the state which the electric motor, the reduction gear and the radial bearing are assembled. It is an exploded perspective view of the state where the electric motor, the reduction gear and the radial bearing are separated.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing for explaining the present invention, components such as members and components having the same function or shape are once described by giving the same reference numerals as much as possible, and then the description thereof will be described. Omit.

FIG. 1 is a perspective view of an electric actuator according to an embodiment of the present invention, and FIG. 2 is a vertical sectional view of the electric actuator according to the present embodiment.

As shown in FIG. 1, the electric actuator 1 according to the present embodiment linearly moves the electric motor 2, the speed reducer 3 that decelerates and outputs the rotation of the electric motor 2, and the rotary motion output from the speed reducer 3. The first motion conversion mechanism 4 that converts to, and the second motion conversion that converts the linear motion output from the first motion conversion mechanism 4 into the rotational motion of the axis in the direction different from the rotation axis 2a of the electric motor 2. It mainly includes a mechanism 5 and a housing 6 for accommodating them.

In this embodiment, a small motor such as a brushed motor or a brushless motor is used as the electric motor 2. The electric motor 2 is connected to a power supply (not shown) via a relay circuit (not shown) which is a switching element provided in the housing 6. A motor holder 16 for holding the electric motor 2 is provided on one end side (reducer 3 side) of the electric motor 2 in the axial direction. The motor holder 16 is assembled to the housing 6. As a result, the electric motor 2 is supported by the housing 6 via the motor holder 16. Further, the motor holder 16 and the electric motor 2 are fixed by a plurality of bolts 17 (see FIG. 2) as fixing members.

The housing 6 is configured by assembling two housing divisions 60. FIG. 1 shows a state in which one of the two housing divisions 60 is removed from the other. By assembling the housing divided bodies 60 to each other via a sealing member (not shown) between the mating surfaces, the internal space of the housing 6 is sealed, and foreign matter such as dust and water is prevented from entering the housing 6. Will be done. In particular, as in the present embodiment, by making the mating surface of the housing split 60 a flat surface parallel to the rotating shaft 2a of the electric motor 2 (without a step), the mating surfaces of the housing split 60 are aligned with each other at the time of assembly. Even if there is a slight deviation between the mating surfaces, a gap is unlikely to occur between the mating surfaces, and it is easy to ensure airtightness. As the sealing member, a solid sealing material such as an O-ring, a rubber sheet, a resin sheet, a joint sheet, or a metal gasket, or a liquid sealing member such as a liquid gasket can be adopted.

As shown in FIG. 2, the first motion conversion mechanism 4 has a screw shaft 7 as a rotating member and a nut 8 as a linear motion member that linearly moves in the direction of the rotation axis as the screw shaft 7 rotates. Have. Thread grooves are formed on the outer peripheral surface of the screw shaft 7 and the inner peripheral surface of the nut 8, respectively, and these screw shafts are directly screwed to form a sliding screw mechanism. As the first motion conversion mechanism 4, a ball screw mechanism in which a plurality of balls are interposed between the screw shaft (rotating member) and the nut (linear motion member) may be used. Both ends of the screw shaft 7 are rotatably supported with respect to the housing 6 via a radial bearing 9 and a thrust bearing 10, respectively. Further, two sets of radial bearings 9 and thrust bearings 10 arranged on one end side and the other end side of the screw shaft 7 are held by bearing holders 18 assembled to the housing 6, respectively.

The second motion conversion mechanism 5 includes a cylindrical output shaft 14 and a swing member 11 attached to the output shaft 14. The output shaft 14 is rotatably supported via a radial bearing 15 (see FIG. 1). The swinging members 11 are attached to both ends of the output shaft 14 in the axial direction, and are configured to swing (rotatably) integrally with the output shaft 14 around the output shaft 14. Further, the output shaft 14 is provided with a connecting hole 14a in which a plurality of irregularities (splines) are formed on the inner peripheral surface. The connecting hole 14a is a hole for inserting an operating shaft provided in an operation target (not shown), and when the operating shaft is inserted into the connecting hole 14a and spline-fitted, the operating shaft is integrated with the output shaft 14. It is rotatably connected. Further, the swing member 11 is provided with a slit-shaped elongated hole 11c that opens at the lower end side shown in FIG. A columnar protrusion 12 protruding from the nut 8 is inserted into the elongated hole 11c. As a result, the nut 8 and the swinging member 11 are configured to be interlocked with each other via the protrusion 12. Further, in the present embodiment, the protrusions 12 are provided on the surfaces of the nuts 8 opposite to each other, and the swinging members 11 having the elongated holes 11c are also provided on both sides of the nut 8 so as to correspond to the protrusions 12. There is.

The speed reducer 3 is arranged between the electric motor 2 and the first motion conversion mechanism 4. In this embodiment, a two-stage planetary reducer 20 is used as the speed reducer 3. Specifically, as shown in FIG. 2, the planetary gear reducer 20 includes a first sun gear 21 as a first-stage input rotating body, a plurality of first planetary gears 22 as a first-stage planetary rotating body, and a first-stage planetary gear 22. A first carrier 23 that also serves as an output rotating body for the eyes and an input rotating body for the second stage, a plurality of second planetary gears 24 as the planetary rotating bodies for the second stage, and a second carrier that serves as the output rotating body for the second stage. It includes a carrier 25 and a ring gear 26 that also serves as a first-stage and second-stage track ring.

The first sun gear 21 is attached to the rotating shaft 2a of the electric motor 2 so as to rotate integrally with the rotating shaft 2a. The ring gear 26 is arranged on the outer periphery of the first sun gear 21 and is assembled so as not to rotate with respect to the housing 6. The plurality of first planetary gears 22 are interposed between the first sun gear 21 and the ring gear 26, and are arranged so as to mesh with each other. Further, each of the first planetary gears 22 is rotatably attached to a flange portion 23b protruding in the outer diameter direction from the cylindrical portion 23a of the first carrier 23. A gear portion 23c in which a plurality of teeth are arranged in the circumferential direction is provided on the outer peripheral surface of the cylindrical portion 23a of the first carrier 23. Further, the rotating shaft 2a of the electric motor 2 is inserted into the inner circumference of the cylindrical portion 23a of the first carrier 23 in a relatively rotatable state. A plurality of second planetary gears 24 that mesh with the gear portion 23c of the first carrier 23 and the ring gear 26 are arranged. Each of the second planetary gears 24 is rotatably attached to a flange portion 25b protruding in the outer diameter direction from the cylindrical portion 25a of the second carrier 25. Further, the second carrier 25 is inserted with one end side of the screw shaft 7. A plurality of irregularities (splines) 25d and 7a extending in the axial direction are formed on the inner peripheral surface of the cylindrical portion 25a of the second carrier 25 and the outer peripheral surface on the one end side of the screw shaft 7, respectively, and these irregularities are formed. By spline fitting the 25d and 7a together, the screw shaft 7 is movable in the axial direction with respect to the second carrier 25 and is integrally rotatably connected in the circumferential direction. Further, on the outer peripheral surface of the cylindrical portion 25a of the second carrier 25, one radial bearing 9 that supports one end side of the screw shaft 7 is arranged.

Here, in the present embodiment, the first carrier 23 also serves as the first-stage output rotating body and the second-stage input rotating body, but functions as the first-stage output rotating body (first planet gear 22). The flange portion 23b) for holding the above and the portion (cylindrical portion 23a having the gear portion 23c) that functions as the input rotating body of the second stage may be formed as separate bodies. Similarly, the ring gear 26 also has a portion that functions as a first-stage orbital ring (a portion that meshes with the first planetary gear 22) and a portion that functions as a second-stage orbital ring (a portion that meshes with the second planetary gear 24). It may be configured separately.

Subsequently, the operation of the electric actuator according to the present embodiment will be described.

Electric power is supplied from the power source to the electric motor 2 by switching the relay circuit, and when the electric motor 2 rotates forward or reverse, the rotational motion is transmitted to the planetary reducer 20 (reducer 3). In the planetary speed reducer 20, the first sun gear 21 rotates integrally with the electric motor 2 (rotating shaft 2a), so that a plurality of first planetary gears 22 that mesh with the electric motor 2 start to rotate. Each of the first planetary gears 22 revolves along the ring gear 26 while rotating, and the revolving motion is output as the rotational motion of the first carrier 23 holding the first planetary gear 22. As a result, the rotational movement of the electric motor 2 is decelerated by one step.

Further, as the first carrier 23 rotates, a plurality of second planetary gears 24 that mesh with the gear portion 23c start rotating. Each second planetary gear 24 revolves along the ring gear 26 while rotating, and the revolving motion is output as the rotational motion of the second carrier 25 holding the second planetary gear 24. As a result, the rotational motion is further decelerated.

The rotary motion decelerated by the speed reducer 3 is transmitted to the first motion conversion mechanism 4. That is, when the second carrier 25 of the planetary reducer 20 rotates, the screw shaft 7 of the first motion conversion mechanism 4 rotates integrally with the second carrier 25. When the screw shaft 7 rotates, the nut 8 moves linearly with the rotation. The nut 8 moves forward in the direction of arrow A1 in FIG. 2 when the electric motor 2 rotates in the forward direction, and moves backward in the direction of arrow A2 in FIG. 2 when the electric motor 2 rotates in the reverse direction.

Then, when the nut 8 moves forward or backward, the swing member 11 is pushed and moved by the protrusion 12 provided on the nut 8. As a result, the swing member 11 swings in the direction of arrow B1 or arrow B2 in FIG. 2, and the output shaft 14 rotates integrally with the swing member 11, so that the linear motion of the nut 8 is caused by the electric motor 2. It is output as a rotary motion of an axis (output shaft 14) in a direction different from that of the rotary shaft 2a. In the present embodiment, since the output shaft 14 is arranged in the direction orthogonal to the rotation shaft 2a of the electric motor 2, the rotational movement of the electric motor 2 is the rotation of the axis orthogonal to the rotation shaft 2a of the electric motor 2. It is output as an exercise.

Hereinafter, the structure for assembling the components such as the electric motor 2 and the speed reducer 3 housed in the housing 6 will be described.

FIG. 3 is a cross-sectional view of a state in which the electric motor 2, the speed reducer 3, and the radial bearing 9 are assembled, and FIG. 4 is an exploded perspective view of the state in which they are separated. Here, the radial bearing 9 assembled to the speed reducer 3 is one of the two radial bearings 9 arranged on both end sides of the screw shaft 7 (the speed reducer 3 side). In the following description, in order to distinguish between the bearing holder 18 that holds the one radial bearing 9 and the bearing holder 18 that holds the other radial bearing 9, the radial bearing 9 on the speed reducer 3 side is held for convenience. The bearing holder 18 will be referred to as a first bearing holder 18A, and the bearing holder 18 holding the other radial bearing 9 will be referred to as a second bearing holder 18B.

As shown in FIGS. 3 and 4, a through hole 16a penetrating in the axial direction is formed in the center of the motor holder 16. The electric motor 2 is assembled to the motor holder 16 by fitting the convex portion 2b provided at one end of the electric motor 2 into the through hole 16a.

The first bearing halter 18A is provided with a radial bearing mounting portion 18c on which the radial bearing 9 is mounted and a thrust bearing mounting portion 18d on which the thrust bearing 10 (see FIG. 2) is mounted. A protruding wall portion 18e protruding in the inner diameter direction of the first bearing holder 18A is interposed between the radial bearing mounting portion 18c and the thrust bearing mounting portion 18d, and the radial bearing 9 and the thrust bearing 10 have the protruding wall portion. They are arranged on opposite sides of each other with 18e in between. In the present embodiment, the radial bearing 9 is arranged on the speed reducer 3 side and the thrust bearing 10 is arranged on the side opposite to the speed reducer 3 side with the protruding wall portion 18e interposed therebetween. Further, since the protruding wall portion 18e is provided, the radial bearing 9 and the thrust bearing 10 are inserted and mounted in the axial direction from opposite sides to the first bearing holder 18A. When the radial bearing 9 and the thrust bearing 10 are inserted into the first bearing holder 18A, the bearings 9 and 10 abut against the protruding wall portion 18e to position them in the axial direction.

The motor holder 16, the ring gear 26, and the first bearing holder 18A have fitting portions 16b, 26a, 26b, 18f that are fitted to each other. These fitting portions 16b, 26a, 26b, 18f are formed of an annular convex portion protruding in the axial direction or an annular concave portion recessed in the axial direction, and the motor holder 16 and the ring gear 26 are axially oriented with each other. It is provided on each of the end faces facing each other and on each end face of the ring gear 26 and the first bearing holder 18A facing each other in the axial direction. It should be noted that the fitting portions 16b, 26a, 26b, 18f are not limited to the case where they are provided over the entire circumference of each of the motor holder 16, the ring gear 26, and the first bearing holder 18A, and are partially provided in the circumferential direction. It may be a plurality of provided convex portions or concave portions.

As described above, in the present embodiment, the motor holder 16, the ring gear 26, and the first bearing holder 18A are configured to be connectable to each other via the fitting portions 16b, 26a, 26b, and 18f. Further, in the present embodiment, the motor holder 16, the ring gear 26, and the first bearing holder 18A are configured to be fixed to each other by a plurality of bolts 30 as fixing members.

In order to assemble each component such as the electric motor 2, the reduction gear 3, and the radial bearing 9 to the housing 6, first, the electric motor 2 is fixed to the motor holder 16 with bolts 17, and the radial bearing 9 is attached to the second carrier. Attach to 25. Next, the motor holder 16 and the speed reducer 3 (ring gear 26) are assembled, and the speed reducer 3 (ring gear 26) and the first bearing holder 18A are assembled.

The assembly of the motor holder 16 and the speed reducer 3 and the assembly of the speed reducer 3 and the first bearing holder 18A are performed by fitting the fitting portions 16b, 26a, 26b, 18f together in the axial direction. .. Then, after assembling these, the motor holder 16, the speed reducer 3 (ring gear 26), and the first bearing holder 18A are further fixed to each other with a plurality of bolts 30. As a result, the electric motor 2, the speed reducer 3, and the radial bearing 9 are assembled to each other via the motor holder 16, the ring gear 26, and the first bearing holder 18A (the state shown in FIG. 3).

Then, the thrust bearing 10 is mounted on the first bearing holder 18A, and the second bearing holder 18B for holding the screw shaft 7, the nut 8, the other radial bearing 9 and the thrust bearing 10 is assembled. Further, by assembling a pair of swinging members 11 to the nut 8 and the output shaft 14, each mechanical element is configured as one assembling unit. Then, each of the mechanical elements assembled in this way is collectively housed in one of the housing divisions 60. Finally, by assembling the other housing split body 60, the assembling work is completed.

As described above, in the present embodiment, by configuring the component parts of each machine element as one assembling unit, the assembling work to the housing 6 can be easily performed. In particular, the electric motor 2, the reduction gear 3, and the radial bearing 9 are formed by fitting the fitting portions 16b, 26a, 26b, 18f of the motor holder 16, the ring gear 26, and the first bearing holder 18A to each other and fixing the bolt 30. Since it is integrated, it is easy to handle without being displaced or separated from each other. Therefore, the assembling work becomes easy and the assembling property is improved.

Further, when the fitting portions 16b, 26a, 26b, and 18f are fitted to each other, the axes X of the electric motor 2, the speed reducer 3, the radial bearing 9, and the screw shaft 7 supported by the electric motor 2, respectively (FIG. 3). (See) can be reliably matched, and subsequent relative movements (deviations) in these radial directions can also be regulated. Therefore, even after the assembly of the component parts to the housing 6 is completed, the axial positions of the electric motor 2, the reduction gear 3, the radial bearing 9, and the screw shaft 7 can be maintained. Therefore, in a high temperature environment, even if the gap between the housing 6 and the component is increased due to the difference in the coefficient of linear expansion between the housing 6 and the component, and the position holding accuracy of the component by the housing 6 is lowered. , The relative positions of the electric motor 2, the speed reducer 3 and the screw shaft 7 can be maintained with high accuracy.

As described above, according to the present invention, it is possible to improve the assembling property of the component parts to the housing and the relative position holding accuracy. Further, according to the present invention, since the relative positions of the components can be maintained with high accuracy even in a high temperature environment, it becomes easy to select different materials for the housing and the components. As a result, for example, high-strength steel can be selected for the components of mechanical elements such as reduction gears and bearings, while aluminum or resin can be selected for the housing, which makes it possible to reduce the weight. ..

Further, in the above-described embodiment, the motor holder 16, the ring gear 26, and the first bearing holder 18A are fixed to each other by the bolt 30, so that the electric motor 2, the reduction gear 3, and the radial bearing 9 are more firmly integrated. Can be done. If the axial separation can be prevented or suppressed only by fitting the fitting portions 16b, 26a, 26b, and 18f together, the bolt 30 may be omitted. For example, by providing a claw-shaped engaging portion that can be engaged in the axial direction at the tip of each fitting portion 16b, 26a, 26b, 18f, it may be possible to reliably prevent the separation in the axial direction.

Further, in the above-described embodiment, since the screw shaft 7 and the second carrier 25 of the speed reducer 3 are spline-fitted, an axial force acts on the screw shaft 7 as the nut 8 moves forward or backward. Even so, by moving the screw shaft 7 in the axial direction with respect to the second carrier 25, it is possible to prevent the axial force from being applied to the second carrier 25 and the second planet gear 24 held by the second carrier 25. It is possible. Further, since the axial force acting in the direction of the second carrier 25 is received by the protruding wall portion 18e of the first bearing holder 18A via the thrust bearing 10, the first sun gear 21 and the first planet gear 22 and the first planet gear 22 It is also possible to avoid an axial force acting on the first carrier 23. As described above, according to the configuration of the above-described embodiment, it is possible to suppress the application of the axial load to the sun gear, the planetary gear, and the like in the speed reducer 3, and it is possible to prevent the possibility of damage thereof. ..

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Of course, it can be carried out in various forms without departing from the gist of the present invention.

In the above-described embodiment, since the ring gear 26 also serves as the speed reducer housing constituting the exterior portion of the speed reducer 3, the fitting portion 26a, which fits the ring gear 26 with the motor holder 16 and the first bearing holder 18A, Although 26b is provided, the ring gear 26 and the speed reducer housing may be configured as separate bodies, and a fitting portion may be provided in the separate speed reducer housing.

Further, the speed reducer 3 is not limited to the two-stage planetary reducer as described above, and may be a one-stage planetary reducer. Further, the speed reducer 3 is not limited to the planetary gear speed reducer that transmits the driving force via gears, and may be configured to transmit the driving force via rollers. That is, the speed reducer 3 is rotatably arranged between the solar roller as an input rotating body into which the driving force is input from the electric motor, the orbital ring arranged on the outer periphery of the solar roller, and the solar roller and the orbital ring. It may be a so-called traction drive type planetary speed reducer having a plurality of planetary rollers as the formed planetary rotating bodies and a carrier as an output rotating body for holding each planetary roller. It is also possible to use a speed reducer having a configuration other than the planetary speed reducer.

1 Electric actuator 2 Electric motor 2a Rotating shaft 3 Reducer 6 Housing 7 Screw shaft 8 Nut 9 Radial bearing 10 Thrust bearing 16 Motor holder 16b Fitting part 18 Bearing holder 18f Fitting part 20 Planetary reducer 21 First sun gear (input) Rotating body)
22 1st planetary gear (planetary rotating body)
23 First carrier (input rotating body and output rotating body)
24 Second planetary gear (planetary rotating body)
25 Second carrier (output rotating body)
26 Ring gear (track ring)
26a Fitting part 26b Fitting part

Claims (5)

An electric motor, a speed reducer that decelerates and outputs the rotation of the electric motor, a screw shaft that rotates by the output of the speed reducer, a bearing that rotatably supports the screw shaft, the electric motor, and the speed reducer. An electric motor including the screw shaft and a housing for accommodating the bearing.
The electric motor, the speed reducer, and the bearing are connected via a fitting portion that regulates radial movement between them. The electric actuator according to claim 1, wherein the electric motor, the speed reducer, and the bearing are fixed by a fixing member so as not to be separated in the axial direction. A motor holder for holding the electric motor, a speed reducer housing constituting the exterior portion of the speed reducer, and a bearing holder for holding the bearing are provided.
The electric actuator according to claim 1 or 2, wherein the motor holder, the speed reducer housing, and the bearing holder are connected via a fitting portion that regulates the radial movement. The speed reducer includes an input rotating body to which a driving force is input, an orbital ring arranged on the outer periphery of the input rotating body, and a plurality of planets that revolve while rotating between the input rotating body and the orbital ring. A planetary speed reducer having a rotating body and an output rotating body that rotates with the revolving motion of the planetary rotating body.
The electric actuator according to claim 3, wherein the track ring also serves as a speed reducer housing having the fitting portion. The speed reducer includes an input rotating body to which a driving force is input, an orbital ring arranged on the outer periphery of the input rotating body, and a plurality of planets that revolve while rotating between the input rotating body and the orbital ring. A planetary speed reducer having a rotating body and an output rotating body that rotates with the revolving motion of the planetary rotating body.
The electric actuator according to any one of claims 1 to 3, wherein the screw shaft is movably connected to the output rotating body in the axial direction.

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