JP7152913B2 - Electric linear motion actuator and electric brake device - Google Patents

Description

The present invention relates to an electric linear motion actuator and an electric brake device using the electric linear motion actuator.

Fig. 1 of Japanese Unexamined Patent Application Publication No. 2002-100020 discloses an electric linear motion actuator provided with a linear motion conversion mechanism that converts the rotary motion of a rotating member rotated about an axis by an electric motor into a linear motion in the axial direction of a linear motion member. there is something

This electric linear motion actuator includes a linear motion conversion mechanism that converts the rotational motion of a rotating member rotated by an electric motor into linear motion in the axial direction of the linear motion member. A braking force can be obtained by pressing a brake pad provided on the linear motion member against a disk rotor that rotates integrally with the wheel.

As shown in more detail in FIG. 2 of this document, the electric linear motion actuator includes a sun roller (rotating shaft) that is rotatable around its axis and immovable in its axial direction, and a plurality of sun rollers that are in rolling contact with the outer periphery of the sun roller. a carrier that holds the plurality of planetary rollers rotatably and revolvingly; a thrust bearing provided interposed between the planetary rollers and the carrier in the axial direction; and the plurality of planetary rollers. and an outer ring (outer ring member) arranged in the following manner.

The outer peripheral surface of the planetary roller has a plurality of circumferential grooves extending along the circumferential direction of the planetary roller, and the inner peripheral surface of the outer ring has a plurality of grooves extending diagonally with respect to the circumferential direction of the outer ring. A spiral ridge is formed that engages a circumferential groove formed in the roller. When the planetary roller rotates and revolves along with the rotation of the sun roller, the engagement between the circumferential groove and the spiral ridge causes the outer ring to move in the axial direction.

The carrier that holds the planetary rollers has a pair of axially opposed carrier plates and a connecting rod that connects the pair of carrier plates to each other. A through hole through which the sun roller is passed is formed in the center of both carrier plates, and the sun roller is inserted through this through hole. A roller shaft that rotatably holds the planetary rollers is held by holding holes formed in both carrier plates.

Thrust bearings are provided to reduce friction between the carrier and the planetary rollers to allow the planetary rollers to rotate smoothly around the roller axis. There are, for example, the following two procedures as assembly procedures (procedures for incorporating the planetary rollers into the carrier) of the electric linear motion actuator according to this configuration.

In the first procedure, as shown in FIG. 12, first, a pair of carrier plates 101 and 102 are connected by a connecting rod 103 to assemble a carrier 104, and then a sun roller 105 is inserted. Then, in a state where the carrier 104 is assembled, the planetary roller 106 and the thrust bearing 107 are kept in alignment with each other in the radial direction, and the planetary roller 106 is inserted between the pair of carrier plates 101 and 102 from the outer diameter side thereof. Insert roller 106 and thrust bearing 107 . After inserting the planetary roller 106 and the thrust 107 bearing, the roller shaft 108 for rotatably supporting the planetary roller 106 is inserted through these axial centers.

In the second procedure, as shown in FIG. 13, first, one carrier plate 101 of a pair of axially opposed carrier plates 101 and 102 forming a carrier is placed in a horizontal state, and then this one carrier plate is placed in a horizontal state. A planetary roller 106 is placed on 101 in a state in which it is radially aligned with a thrust bearing 107 . Then, the roller shaft 108 is inserted through the axial center of the planetary roller 106 and the thrust bearing 107 , and the connecting rod 103 , the sun roller 105 and one end of the roller shaft 108 are inserted into one of the carrier plates 101 . Further, the connecting rod 103, the sun roller 105, and the other ends of the roller shafts 108 are inserted into the insertion holes formed in the other carrier plate 102 opposite to the one carrier plate 101. FIG.

JP 2016-98873 A

In the above first procedure, the planetary rollers 106 and the thrust bearings 107 must be carefully inserted between the pair of carrier plates 101 and 102 so that the radial positions of the planetary rollers 106 and 107 do not shift. It is difficult to shorten the cycle time of the work of inserting the roller 106 . In the second procedure, the plurality of connecting rods 103, the sun rollers 105, the planetary rollers 106, and the plurality of roller shafts 108 inserted into the thrust bearings 107 must be inserted into the other carrier plate 102 at the same time. Therefore, a dedicated jig is required to assist the insertion, and the insertion process tends to be complicated.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to smoothly assemble an electric linear motion actuator.

In order to solve this problem, in the present invention, a sun roller that is rotatable around an axis and immovable in the axial direction, a plurality of planetary rollers that are in rolling contact with the outer periphery of the sun roller, and the plurality of planetary rollers are provided. a carrier rotatable and revolatable; a thrust bearing interposed between the planetary rollers and the carrier in the axial direction; an outer ring arranged to surround the plurality of planetary rollers; In an electric linear motion actuator having a linear motion conversion mechanism having circumferential direction engaging portions having different lead angles formed on the outer peripheral surface of the roller and the inner peripheral surface of the outer ring, the planetary roller and The electric linear motion actuator is configured, further comprising a position restricting member for maintaining the radial position of the thrust bearing in a coaxial state.

In this way, when assembling the electric linear motion actuator, the operator does not need to pay attention to the radial positional deviation between the planetary roller and the thrust bearing, so the assembly can be smoothly performed. Cost reduction and assembly work can be automated.

In the above configuration, the position regulating member may be provided on the inner diameter side of the planetary roller and support the inner diameter surface of the retainer of the thrust bearing. In this case, the position regulating member is provided on the inner diameter side of the planetary roller so as to be interposed between the planetary roller and a roller shaft that rotatably supports the planetary roller. It can be configured as follows.

With this configuration, the position regulating member can reliably prevent radial displacement between the planetary roller and the thrust bearing. In addition, the end faces of the planetary rollers are ground to form the raceway surfaces of the thrust bearings, but by providing the position regulating member on the inner diameter side of the planetary rollers, the function of the raceway surfaces is not hindered. no. Moreover, the slide bearing is a member that has been used to smooth the rotation between the planetary roller and the roller shaft. Therefore, by making this slide bearing function as a position regulating member, it is possible to prevent an increase in the number of parts and reduce the manufacturing cost.

In the above configuration, the position regulating member may be provided on the outer diameter side of the planetary roller and support the outer diameter surface of the retainer of the thrust bearing.

With this configuration, the position restricting member can reliably prevent the planetary roller and the thrust bearing from being dislocated in the radial direction in the same manner as when the position restricting member is provided on the inner diameter side of the planetary roller.

In each of the above configurations, the position regulating member and the planetary rollers may be integrally formed.

In this way, the step of press-fitting the position regulating member into the planetary rollers becomes unnecessary, so that the electric linear motion actuator can be assembled more smoothly.

The position regulating member is a projection integrally formed so as to protrude from the inner diameter surface or the outer diameter surface of the retainer of the thrust bearing in the axial direction. can also be configured to support the

By doing so, the assembly of the electric linear motion actuator can be performed more smoothly, as in the case where the position regulating member and the planetary roller are integrally formed.

In each of the configurations described above, the sliding bearing can be made of a sintered alloy or resin.

By doing so, it is possible to improve desired characteristics such as improved durability of the slide bearing and improved smoothness of rotation.

The electric linear motion actuator according to each configuration includes a brake disk that rotates integrally with the wheel, a pair of brake pads that face each other in the axial direction with the brake disk interposed therebetween, and linearly drives the brake pads in the axial direction. It can be adopted in an electric brake device having this electric linear motion actuator.

In this way, as the assembling efficiency of the electric linear motion actuator is improved, the assembling efficiency of the electric braking device itself can also be improved, and the manufacturing cost of the electric braking device can be reduced.

The electric linear motion actuator according to the present invention is provided with a position regulating member that keeps the radial positions of the planetary rollers and the thrust bearing interposed between the planetary rollers and the carrier in a coaxial state. The operator does not need to pay attention to the radial positional deviation of the planetary rollers and the thrust bearing during assembly. Therefore, the assembly can be smoothly performed, and the assembly cost can be reduced and the assembly work can be automated.

Sectional view of an electric brake device according to the present invention Side view of the electric brake device shown in FIG. Sectional view of an electric linear motion actuator employed in the electric brake device of FIG. Sectional view of a linear motion conversion mechanism employed in the electric linear motion actuator shown in FIG. Cross-sectional view along line VV in FIG. Cross-sectional view of the main part of FIG. Cross-sectional view of the main part of FIG. Sectional drawing which shows the 1st modification of FIG. Cross-sectional view showing a second modification of FIG. Sectional view showing the third modification of FIG. Sectional view showing the fourth modification of FIG. Cross-sectional view showing a general assembly procedure (first procedure) for an electric linear actuator Cross-sectional view showing a general assembly procedure (second procedure) for an electric linear motion actuator

An embodiment of an electric brake device 10 and an electric linear motion actuator 14 according to the present invention will be described with reference to FIGS. 1 to 7. FIG.

As shown in FIG. 1, this electric brake device 10 includes a brake disc 11 that rotates integrally with a wheel (not shown), and a pair of brake pads 12 and 13 that are axially opposed to each other with the brake disc 11 therebetween. , an electric linear motion actuator 14 that linearly drives the brake pad 13 in the axial direction is a main component, and the brake pads 12 and 13 are pressed against the brake disc 11 by power transmitted from an electric motor 15 (see FIG. 3). to generate a braking force. In the following description, the axial direction of the brake pads 12 and 13 (leftward in FIG. 1) as viewed from the electric linear actuator 14 is referred to as front, and the opposite direction (rightward in FIG. 1) is referred to as rear.

The electric brake device 10 has a caliper body 19 in which a pair of opposing portions 16 and 17 that face each other in the axial direction with the brake disc 11 interposed therebetween are connected by a bridge 18 located on the outer diameter side of the brake disc 11 . The brake pads 12 and 13 are provided between one facing portion 16 of the caliper body 19 and the brake disc 11 and between the other facing portion 17 and the brake disc 11 via back plates 20 and 21, respectively. It is Each brake pad 12 , 13 is guided in the axial direction of the brake disc 11 by a pad pin (not shown) attached to the caliper body 19 and a slide portion (not shown) provided on the caliper bracket 22 .

As shown in FIG. 2, the caliper body 19 is movably supported in the axial direction of the brake disc 11 by a slide pin 23 attached to a caliper bracket 22 fixed to a knuckle (not shown) that supports the wheel. there is As a result, when the brake pad 13 moves axially forward and is pressed against the brake disc 11, the reaction force received from the brake disc 11 causes the caliper body 19 to move axially rearward. Thus, the brake pad 12 on the opposite side is also pressed against the brake disc 11.例文帳に追加

As shown in FIGS. 1, 3, etc., one opposing portion 17 of the caliper body 19 includes a cylindrical caliper housing 17A having open front and rear ends in the axial direction, and a cylindrical caliper housing 17A provided at the rear end in the axial direction of the caliper housing 17A. and a caliper flange 17B protruding to the side.

A linear motion converting mechanism 24 is incorporated in the caliper housing 17A. The linear motion conversion mechanism 24 converts the rotary motion of the rotary member, which is rotatable about the axis and immovable in the axial direction by the electric motor 15, into the linear motion of the linear motion member, which is non-rotatable about the axis and movable in the axial direction. It has a function to convert to

As shown in FIG. 4 and the like, the direct-acting conversion mechanism 24 includes a round-bar-shaped sun roller 25 that is rotatable around an axis and immovable in the axial direction, to which the rotation of the electric motor 15 is input, and an outer circumference of the sun roller 25 . a plurality of planetary rollers 26 arranged at regular intervals in the circumferential direction, a carrier 27 holding the plurality of planetary rollers 26 so that they can rotate and revolve, and between the planetary rollers 26 and the carrier 27 in the axial direction. A thrust bearing 28 interposed therebetween, a cylindrical outer ring 29 disposed so as to surround the plurality of planetary rollers 26 inside thereof, and formed on the outer peripheral surface of the planetary rollers 26 and the inner peripheral surface of the outer ring 29. Circumferential engagement portions 30 and 31 formed on the planetary roller 26 and the outer ring 29, respectively, are engaged with each other so that the rotation member It is a planetary roller screw mechanism that converts the rotation about the axis of the linear motion member into the linear motion in the axial direction of the linear motion member. In the direct-acting conversion mechanism 24, the rotating member corresponds to the sun roller 25, and the direct-acting member corresponds to the outer ring 29, respectively.

As shown in FIG. 3, the electric motor 15 is attached to a flange 33B provided at the axial rear end of the caliper housing 17A. A reduction mechanism 32 is provided between the electric motor 15 and the sun roller 25 to reduce the rotation speed of the motor shaft 15A of the electric motor 15 and transmit the rotation to the sun roller 25 . The deceleration mechanism 32 is housed in a cover 33A and a flange 33B so as to cover the rear end opening of the caliper housing 17A in the axial direction.

As shown in FIGS. 2 and 3, the speed reduction mechanism 32 includes a first gear 32A that rotates around the axis integrally with the rotor shaft 15A of the electric motor 15, a second gear 32B that meshes with the first gear 32A, and a second gear 32B that meshes with the first gear 32A. It has a gear 32B and a third gear 32C that rotates with the meshing sun roller 25. As shown in FIG. The rotation of the electric motor 15 is transmitted to the sun roller 25 through the plurality of gears 32A, 32B, 32C while being sequentially decelerated.

The circumferential engaging portion 30 formed on the outer peripheral surface of the planetary roller 26 includes a plurality of circumferential grooves extending along the circumferential direction of the planetary roller 26 (hereinafter, denoted by the same reference numerals as the circumferential engaging portion 30). ). A circumferential engaging portion 31 formed on the inner peripheral surface of the outer ring 29 engages with a circumferential groove 30 formed on the planetary roller 26 extending obliquely with respect to the circumferential direction of the outer ring 29 . (Hereinafter, the same reference numerals as those of the circumferential engaging portion 31 are attached.). That is, the lead angles of the circumferential groove 30 and the spiral ridge 31 are different from each other, and when the planetary roller 26 rotates with the two engaged, the outer ring 29 moves relative to the planetary roller 26 in the axial direction. In this embodiment, the circumferential groove 30 with a lead angle of 0 degrees is provided on the outer periphery of the planetary roller 26, but instead of the circumferential groove 30, a spiral groove with a lead angle different from that of the spiral ridge 31 may be used.

As shown in FIGS. 4, 5, etc., an insertion hole is formed in the axial center of the planetary roller 26, and the roller shaft 34 is inserted through the insertion hole. The roller shaft 34 causes the planetary roller 26 to rotate about its axis. Slide bearings 35A and 35B interposed between the roller shaft 34 and the front end side and the rear end side of the insertion hole are provided. The planetary roller 26 smoothly rotates around the roller shaft 34 by the sliding bearings 35A and 35B.

As shown in FIGS. 6 and 7, the sliding bearing 35B on the rear end side is provided so as to protrude slightly rearward from the axial rear end surface of the planetary roller 26. As shown in FIGS. The end of the sliding bearing 35B protruding rearward functions as a position regulating member 36 that maintains the radial positions of the planetary roller 26 and the thrust bearing 28 in a coaxial state, as will be described later. The sliding bearings 35A and 35B are made of sintered alloy, but can also be made of resin. In this embodiment, the end of the sliding bearing 35B functions as the position regulating member 36, but the position regulating member 36 may be a separate member from the sliding bearing 35B.

A preload spring 37 is stretched over both ends of each roller shaft 34 so as to circumscribe the roller shafts 34 of all the planetary rollers 26 arranged at intervals in the circumferential direction. With this arrangement, each planetary roller 26 is pressed against the outer periphery of the sun roller 25 by the preload spring 37, so slippage between the planetary roller 26 and the sun roller 25 can be prevented.

The carrier 27 includes a front carrier plate 27A that holds the planetary rollers 26 from the front in the axial direction, a rear carrier plate 27B that holds the planetary rollers 26 from the rear in the axial direction, and a plurality of connecting rods that connect the two carrier plates 27A and 27B. 27C. Each of the carrier plates 27A and 27B has a disc-shaped outer shape, and a sliding bearing 38 is provided between each carrier plate 27A and 27B and the sun roller 25. As shown in FIG. A snap ring 39 is provided axially forward of the front carrier plate 27A to restrict the axially forward movement of the carrier 27 .

Both carrier plates 27A and 27B have a through hole formed in the center thereof for inserting the sun roller 25, and a plurality of elongated holes extending in the radial direction. The hole holds the sun roller 25 movably in the radial direction. The carrier 27 rotates around the axis of the sun roller 25 as the planetary rollers 26 revolve.

A thrust bearing 28 is provided between the axial rear end of the planetary roller 26 and the rear carrier plate 27B. As shown in FIGS. 6, 7, etc., the inner diameter surface of the retainer 28A that constitutes the thrust bearing 28 is provided with a protruding end portion (position regulating portion) of the sliding bearing 35B that protrudes rearward from the axial rear end surface of the planetary roller 26. member 36) is inserted. The thrust bearing 28 allows the planetary roller 26 to rotate smoothly around the roller shaft 34 and the rear carrier plate 27B to rotate smoothly around the roller shaft 34 .

By inserting the position restricting member 36 into the inner diameter surface of the retainer 28A of the thrust bearing 28, the radial positions of the planetary roller 26 and the thrust bearing 28 are fixed. Then, when assembling the electric linear motion actuator 14 according to the general assembly procedure shown in FIG. Therefore, the assembly can be smoothly performed, and the assembly cost can be reduced.

A pressing member 40 is provided at the axially forward open end of the outer ring 29 . The pressing member 40 has a disc-shaped disc portion 40A and an annular flange portion 40B standing axially rearward from the outer peripheral edge of the disc portion 40A. The outer circumference of the portion is fitted into the inner circumference of the outer ring 29 .

A spacer 41 is provided behind the rear carrier plate 27B in the axial direction. The spacer 41 rotates about the axis of the sun roller 25 integrally with the rear carrier plate 27B.

A load sensor 43 is provided behind the spacer 41 in the axial direction via a thrust bearing 42 . This load sensor 43 detects the reaction force acting on the outer ring 29 from the brake pad 13 during braking via the planetary roller 26, the thrust bearing 28, the rear carrier plate 27B, the spacer 41, and the thrust bearing 42. It has a function of detecting the braking force by receiving it. A bearing 44 is provided between the load sensor 43 and the sun roller 25 so that they can rotate relative to each other. A retaining ring 45 is provided at the front end of the load sensor 43 in the axial direction, and the retaining ring 45 positions the load sensor 43 so as not to move forward in the axial direction.

A circumferential groove 46 is formed at the end of the fitting portion of the outer ring 29 to the caliper housing 17A. The small diameter end of the boot 47 is fitted into the circumferential groove 46, and the large diameter end of the boot 47 is fitted into the circumferential groove 48 formed on the inner circumference of the caliper housing 17A. With this configuration, the boot 47 isolates the internal mechanism of the electric linear motion actuator 14 from the outside, ensuring that foreign matter such as muddy water does not enter between the sliding surfaces of the outer surface of the outer ring 29 and the inner surface of the caliper housing 17A. can be prevented.

As shown in FIG. 1, an axial front surface of the pressing member 40 is formed with a detent groove 40C. Further, on the rear surface of the back plate 21 in the axial direction, a detent projection 21A is formed which engages with the groove end of the detent groove 40C. By engaging the detent projection 21A with the end portion of the detent groove 40C, the pressing member 40 (outer ring 29) is detented against the caliper housing 17A.

The operation of this electric linear motion actuator 14 will be described.

When the electric motor 15 is driven to rotate the sun roller 25 in one direction around the axis, the planetary roller 26 revolves while rotating. At this time, the outer ring 29 and the planetary rollers 26 move relative to each other in the axial direction due to the difference in lead angle between the spiral ridge 31 and the circumferential groove 30 , but the planetary rollers 26 move axially together with the carrier 27 due to the retaining ring 39 . is regulated, the planetary roller 26 does not move in the axial direction, and the outer ring 29 and the pressing member 40 move forward in the axial direction. As a result, the brake pad 13 pressed forward in the axial direction by the pressing member 40 is pressed against the brake disc 11 to exert a braking force.

On the other hand, when the sun roller 25 rotates about its axis in the opposite direction, the outer ring 29 and the pressing member 40 move axially rearward by the action opposite to the above. As a result, the brake pad 13 is no longer pressed against the brake disc 11, and the braking force is released.

A first modification of the configuration shown in FIG. 6 is shown in FIG. In this first modification, the position regulating member 36 is a ring-shaped member that is provided on the outer diameter side of the planetary roller 26 and is a separate member from the planetary roller 26. , support the outer diameter side of the retainer 28A of the thrust bearing 28. As shown in FIG. The configuration according to the first modification also exhibits the function of fixing the radial positions of the planetary rollers 26 and the thrust bearings 28, similarly to the configuration shown in FIG.

A second modification of the configuration shown in FIG. 6 is shown in FIG. In this second modification, the position regulating member 36 is a projecting portion integral with the planetary rollers 26, in which the inner diameter surface of the planetary roller 26 protrudes axially outward. , support the inner diameter side of the retainer 28A of the thrust bearing 28. As shown in FIG. In the configuration according to the second modified example, similarly to the configuration shown in FIG. 6, the function of fixing the radial positions of the planetary rollers 26 and the thrust bearings 28 is exhibited. In this second modified example, the inner diameter surface of the planetary roller 26 has the function of a slide bearing. It can also be configured as

A third modification of the configuration shown in FIG. 6 is shown in FIG. In this third modification, the position regulating member 36 is a projecting portion integral with the planetary rollers 26 that protrudes the outer diameter surface of the planetary roller 26 outward in the axial direction. , support the outer diameter side of the retainer 28A of the thrust bearing 28. As shown in FIG. The configuration according to the third modification also exhibits the function of fixing the radial positions of the planetary rollers 26 and the thrust bearings 28, similarly to the configuration shown in FIG.

A fourth modification of the configuration shown in FIG. 6 is shown in FIG. In this fourth modified example, the position regulating member 36 is a projecting portion integral with the retainer 28A, in which the inner diameter surface of the retainer 28A of the thrust bearing 28 protrudes axially outward. The outer diameter surface supports the inner diameter side of the insertion hole formed in the axial center of the planetary roller 26 . The configuration according to the fourth modification also exhibits the function of fixing the radial positions of the planetary rollers 26 and the thrust bearings 28, as in the configuration shown in FIG. Although not shown, the position regulating member 36 is formed by a protrusion that protrudes axially outward from the outer diameter surface of the retainer 28A. It can also be configured to support.

The electric brake device 10 and the electric linear motion actuator 14 according to each of the above-described embodiments are merely examples for solving the problem of the present invention, which is to smoothly assemble the electric linear motion actuator 14 . In particular, the formation position and shape of the position regulating member 36 can be appropriately changed as long as the radial positions of the planetary roller 26 and the thrust bearing 28 can be fixed.

11 Brake discs 12, 13 Brake pad 14 Electric linear motion actuator 24 Linear motion conversion mechanism 25 Sun roller 26 Planetary roller 27 Carrier 28 Thrust bearing 28A Cage 29 Outer ring 30 Circumferential engagement portion (circumferential groove)
31 Circumferential engaging portion (spiral ridge)
34 roller shaft 35B sliding bearing 36 position restricting member

Claims (8)

an axially rotatable and axially immovable sun roller (25);
a plurality of planetary rollers (26) in rolling contact with the outer periphery of the sun roller (25);
a carrier (27) holding the plurality of planetary rollers (26) rotatably and revolvingly;
a thrust bearing (28) interposed between the planetary roller (26) and the carrier (27) in the axial direction;
an outer ring (29) arranged to surround the plurality of planetary rollers (26);
circumferential engaging portions (30, 31) having different lead angles formed on the outer peripheral surface of the planetary roller (26) and the inner peripheral surface of the outer ring (29), respectively;
In an electric linear motion actuator comprising a linear motion conversion mechanism (24) having
It is fixed to or integrally provided with one of the planetary roller (26) or the cage (28A) of the thrust bearing (28), and the planetary roller (26) or the cage (28A) of the thrust bearing (28). further comprising a position regulating member (36) that maintains the radial positions of the planetary roller (26) and the thrust bearing (28) in a coaxial state by inserting the other of the two coaxially. dynamic actuator. 2. The position regulating member (36) is provided on the inner diameter side of the planetary roller (26) and supports the inner diameter surface of the retainer (28A) of the thrust bearing (28). The electric linear motion actuator described in . The position regulating member (36) is provided on the inner diameter side of the planetary roller (26) and interposed between a roller shaft (34) that rotatably supports the planetary roller (26). 3. The electric linear motion actuator according to claim 2, wherein the slide bearing (35B) protrudes from the axial end face of the (26). The position regulating member (36) is provided on the outer diameter side of the planetary roller (26) and supports the outer diameter surface of the retainer (28A) of the thrust bearing (28). Item 1. The electric linear motion actuator according to item 1. The electric linear motion actuator according to any one of claims 1 to 4, wherein the position regulating member (36) and the planetary roller (26) are integrally formed. The position regulating member (36) is a protrusion integrally formed so as to protrude axially from the inner diameter surface or the outer diameter surface of the retainer (28A) of the thrust bearing (28). 2. The electric linear motion actuator according to claim 1, wherein the planetary roller (26) is supported on the inner diameter side or the outer diameter side. 4. The electric linear motion actuator according to claim 3, wherein the sliding bearing (35B) is made of a sintered alloy or resin. a brake disc (11) rotating integrally with the wheel;
a pair of brake pads (12, 13) axially opposed to each other with the brake disc (11) therebetween;
The electric linear motion actuator (14) according to any one of claims 1 to 7, which linearly drives the brake pads (12, 13) in the axial direction;
An electric brake device having

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