JP2011074950A - Electrically operated linear actuator and electrically operated brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To allow an external thrust load to be loaded equally on each planetary roller revolving while spinning, engaged on circumferential grooves thereof with a helical ridge on an outer ring member. <P>SOLUTION: A distance from a support end surface 6b of the each planetary roller 6 supported by a thrust bearing 18 to a predetermined reference position on the circumferential grooves 6a is set to a different dimension from the others such that the position of the support end surface 6b of the each planetary roller 6 in the axial direction matches the others when the helical ridge 5a of the outer ring member 5 fits into the circumferential grooves 6a of the each planetary roller 6. This allows the external thrust load to be loaded equally on the each planetary roller 6 revolving while spinning, engaged on the circumferential grooves 6a thereof with the helical ridge 5a on the outer ring member 5. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electric linear motion actuator that linearly drives a driven object by converting the rotational motion of an electric motor into linear motion, and an electric brake that presses a brake member against the braked member using the electric linear motion actuator Relates to the device.

  Many of the electric linear actuators that convert the rotational motion of the electric motor into linear motion to drive the driven object linearly employ a ball screw mechanism or a ball ramp mechanism as the motion conversion mechanism. In many cases, a gear reduction mechanism such as a planetary gear reduction mechanism is incorporated so that a large linear driving force can be obtained (see, for example, Patent Document 1).

  The ball screw mechanism and the ball ramp mechanism employed in the electric linear actuator described above have a certain degree of boosting function by a motion conversion mechanism along the lead screw thread and the inclined cam surface. It is not possible to secure a large boosting function that is necessary for the above. For this reason, in the electric linear actuator that employs these motion conversion mechanisms, a separate reduction mechanism such as a planetary gear reduction mechanism is incorporated to increase the driving force. In this way, a separate reduction mechanism is incorporated. Impedes the compact design of the electric linear actuator.

  In response to such a problem, the present inventors can secure a large boosting function without incorporating a separate speed reduction mechanism, and as an electric linear actuator suitable for an electric brake device having a relatively small linear motion stroke. A plurality of planets rotatably supported by a carrier between a rotating shaft to which rotation is transmitted from the rotor shaft of the electric motor and an outer ring member fixed to the inner diameter surface of the housing on the outer diameter side of the rotating shaft; These planetary rollers revolve while rotating around the rotating shaft as the rotating shaft rotates by interposing rollers, and spiral ridges are provided on the inner diameter surface of the outer ring member, and the outer diameter surface of the planetary roller is provided. A circumferential groove into which the spiral ridge is fitted at the same pitch as the spiral ridge is provided so that the outer ring member and the carrier move relative to each other in the axial direction, and the rotational motion of the rotating shaft is converted into the linear motion of the carrier. Carry Have previously developed a mechanism that an output member for linearly driving a driven object (see Patent Document 2). In addition, a mechanism has been proposed in which the movement of the carrier in the axial direction is regulated to make the outer ring member an output member that linearly moves (Japanese Patent Application No. 2008-233380).

  The electric linear actuator using the carrier described in Patent Document 2 as an output member that linearly moves is a thrust bearing that supports the rotation of each planetary roller that linearly moves together with the carrier, and the carrier linearly drives the driven object. Thus, it is arranged on the advancing side so as to receive a thrust load applied to the carrier. In addition, the electric linear motion actuator in which the outer ring member proposed in Japanese Patent Application No. 2008-233380 is an output member that linearly moves is a thrust bearing that supports the rotation of each planetary roller, and the outer ring member linearly drives the driven object. The thrust ring is disposed on the opposite side to the advancing side so as to receive a thrust load applied to the outer ring member.

  On the other hand, many hydraulic brake devices have been adopted, but in recent years, with the introduction of advanced brake control such as ABS (Antilock Brake System), these controls are performed without a complicated hydraulic circuit. Electric brake devices that can do this are attracting attention. The electric brake device operates an electric motor in response to a brake pedal depression signal or the like, and incorporates an electric linear actuator as described above into a caliper body to press a brake member against a member to be braked (for example, a patent) Reference 3).

JP-A-6-327190 JP 2007-32717 A JP 2003-343620 A

  The electric linear actuator described in Patent Document 2 and the electric linear actuator proposed in Japanese Patent Application No. 2008-233380 can secure a large boosting function with a compact design without incorporating a separate speed reduction mechanism. However, the axial positions of the planetary rollers that are supported by the carrier so as to revolve and engage with the spiral ridges of the outer ring member and the circumferential grooves are slightly shifted from each other due to the difference in the revolving positions in the circumferential direction. For this reason, the external thrust load applied to the carrier as the output member or the outer ring member is not equally applied to each planetary roller via the thrust bearing that supports rotation, and the life of some planetary rollers is shortened. There is a problem.

  Accordingly, an object of the present invention is to allow an external thrust load to be evenly applied to each planetary roller that revolves while rotating by being engaged with a spiral protrusion of a outer ring member and a circumferential groove. .

  In order to solve the above-described problems, the present invention provides a rotation shaft between a rotation shaft that transmits rotation from a rotor shaft of an electric motor and an outer ring member that is fitted on the inner diameter surface of the housing on the outer diameter side of the rotation shaft. A plurality of planetary rollers rotatably supported by the carrier so that each of the planetary rollers revolves while rotating around the rotation shaft as the rotation shaft rotates, and the inner diameter of the outer ring member A spiral ridge is provided on the surface, and a circumferential groove into which the spiral ridge is fitted at the same pitch as the spiral ridge is provided on the outer diameter surface of each planetary roller, so that the outer ring member and the carrier are moved in the axial direction. Relative movement is performed to convert the rotational motion of the rotating shaft into linear motion of the carrier so that the driven object is linearly driven, and the rotation of each planetary roller is thrust to the carrier that linearly drives the driven object. On the end face where In the electric linear motion actuator supported on the carrier by a last bearing, the axial position of the circumferential groove of each planetary roller supported by the thrust bearing is set to the spiral convexity of the outer ring member fitted in the circumferential groove. A configuration provided with circumferential groove position adjusting means for adjusting to match the axial position of the strip was adopted.

  The present invention also supports a carrier rotatably between a rotating shaft that transmits rotation from a rotor shaft of an electric motor and an outer ring member that is fitted on the inner diameter surface of the housing on the outer diameter side of the rotating shaft. The plurality of planetary rollers are interposed so that each of the planetary rollers revolves while rotating around the rotation shaft as the rotation shaft rotates, and a spiral protrusion is provided on the inner diameter surface of the outer ring member. The outer circumferential surface of each planetary roller is provided with a circumferential groove into which the spiral ridge is fitted at the same pitch as that of the spiral ridge, and the outer ring member and the carrier are moved relative to each other in the axial direction, and the rotating shaft The rotational motion of the outer ring member is converted into the linear motion of the outer ring member so that the driven object is linearly driven, and the rotation of each planetary roller is performed on the side where the thrust load is applied to the outer ring member that linearly drives the driven object. On the opposite end face to the thrust bearing In the electric linear actuator supported by the carrier, the axial ridges of the circumferential grooves of the planetary rollers supported by the thrust bearings are arranged on the spiral ridges of the outer ring member fitted into these circumferential grooves. A configuration in which circumferential groove position adjusting means for adjusting so as to match with the axial direction position is also adopted.

  That is, the circumferential groove that adjusts the axial position of the circumferential groove of each planetary roller supported by the thrust bearing to match the axial position of the spiral ridge of the outer ring member that fits into these circumferential grooves. By providing the position adjusting means, each planetary roller that revolves while rotating by rotating with the spiral ridge of the outer ring member and the circumferential groove is externally loaded on the carrier or outer ring member that drives the driven object linearly. The thrust load was uniformly applied via the thrust bearings supporting these rotations.

  The circumferential groove position adjusting means includes a spiral ridge that fits the circumferential groove with a distance from a support end surface supported by the thrust bearing of each planetary roller to a predetermined reference position of the circumferential groove. Different dimensions may be set so that the axial positions match.

  When the circumferential groove is formed over the entire axial length of each planetary roller and the distance from the support end surface to the predetermined reference position of the circumferential groove is set to a different dimension, any planetary roller is used. When an incompletely shaped circumferential groove whose end face side rises from the groove bottom is formed on any one of the end face sides, chamfering may be performed so as to remove the rising portion of the incompletely shaped circumferential groove.

  Provided on the support end surface side of the circumferential groove formed closest to the support end surface of each planetary roller is a small diameter portion equal to or smaller than the groove bottom diameter of the circumferential groove, and the axial length of the small diameter portion is changed. Thus, the distances from the support end surface of each planetary roller to the reference position of the circumferential groove can be set to different dimensions. The reason why the small diameter portion is set to a diameter equal to or smaller than the groove bottom diameter of the circumferential groove is to prevent interference with the spiral ridges of the outer ring member.

  By setting the axial length of the small diameter portion to be equal to or less than the pitch of the circumferential groove, the circumferential groove can be provided by effectively utilizing the outer diameter surface of the planetary roller.

  The small diameter portion may be formed of a separate ring member.

  The circumferential groove position adjusting means may include spacers having different axial thicknesses between the bearing ring of the thrust bearing supporting the planetary rollers and the carrier.

  The spacer may be formed integrally with the bearing or carrier of the thrust bearing.

  The planetary rollers preferably have the same axial length.

  The present invention further includes an electric linear actuator that linearly drives the brake member by converting the rotational motion of the electric motor into a linear motion of the output member, and that electrically presses the brake member that is linearly driven against the member to be braked. In the type brake device, by adopting a configuration using any one of the above-described electric linear actuators as the electric linear actuator, the helical ribs of the outer ring member are engaged with the circumferential grooves while rotating. A thrust load from the outside applied to the carrier or outer ring member that linearly drives the driven object is equally applied to each revolving planetary roller.

  The electric linear actuator of the present invention matches the axial position of the circumferential groove of each planetary roller supported by the thrust bearing with the axial position of the spiral ridge of the outer ring member fitted into these circumferential grooves. Since the circumferential groove position adjusting means for adjusting is provided, the planetary roller that revolves while rotating by engaging with the spiral protrusion of the outer ring member and the circumferential groove, or a carrier that linearly drives the driven object or A thrust load from the outside applied to the outer ring member can be equally applied, and the life of each planetary roller can be extended.

  In addition, since the electric brake device according to the present invention uses any of the above-described electric linear actuators for the electric linear actuator that presses the brake member that is linearly driven against the member to be braked, the brake member is linearly moved. An external thrust load applied to the driving carrier or the outer ring member can be equally applied to each planetary roller, and the life of each planetary roller can be extended.

1 is a longitudinal sectional view showing an electric linear actuator according to a first embodiment. Sectional view along the line II-II in FIG. Sectional view along line III-III in FIG. FIG. 1 is a developed plan view of a planetary roller that engages with the spiral ridges of the outer ring member of FIG. 1. (A), (b) is a front view explaining the formation method of the planetary roller of FIG. (A), (b) is a front view which shows the modification of the planetary roller of FIG. 4, respectively. 1 is a longitudinal sectional view showing an electric brake device employing the electric linear actuator of FIG. A longitudinal sectional view showing an electric linear actuator of a second embodiment FIG. 8 is a developed plan view of a planetary roller that engages with the spiral ridges of the outer ring member of FIG. A longitudinal section showing an electric linear actuator of a 3rd embodiment FIG. 10 is a developed plan view of the planetary roller that engages with the spiral ridge of the outer ring member of FIG. 10.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show a first embodiment. As shown in FIGS. 1 to 3, the electric linear actuator is provided with a flange 1b projecting to one end of a cylindrical portion 1a of the housing 1, and the electric motor 2 is connected to the cylindrical portion 1a on the flange 1b. Installed in parallel. The rotation of the rotor shaft 2a of the electric motor 2 is transmitted to the rotating shaft 4 disposed at the center of the cylindrical portion 1a by the gears 3a, 3b, 3c, and rotates with the outer ring member 5 fixed to the inner diameter surface of the cylindrical portion 1a. Four planetary rollers 6 interposed between the shafts 4 are rotatably supported by the carrier 7 and revolve while rotating around the rotation shafts 4 to rotate on the inner surface of the outer ring member 5. The carrier 7 supporting the planetary roller 6 and the outer ring member 5 are relatively moved in the axial direction by the engagement of the provided spiral ridge 5a and the circumferential groove 6a provided on the outer diameter surface of the planetary roller 6. It is like that. In this embodiment, the movement of the outer ring member 5 in the axial direction is restricted, the carrier 7 linearly moves, and the driven object is linearly driven as an output member.

  A lid 1c is attached to the side of the housing 1 where the flange 1b is provided, and the gears 3a, 3b, 3c are arranged so as to mesh with each other in the same axial section of the space covered with the lid 1c. A shaft support member 8 is fitted on the lid 1c side of the cylindrical portion 1a, and the base end side of the rotating shaft 4 to which the gear 3c is attached is supported by the shaft support member 8 with a ball bearing 9. The shaft support member 8 is brought into contact with the end surface of the outer ring member 5, and the outer ring member 5 is restricted from moving in the axial direction by a retaining ring 10a for retaining the shaft supporting member 8 and a retaining ring 10b on the opposite side. . An intermediate gear 3b meshed with the gear 3a and the gear 3c attached to the rotor shaft 2a is supported by a ball bearing 12 on a shaft pin 11 passed between the flange 1b and the lid 1c.

  The carrier 7 is supported at both ends by a carrier body 7a and a support plate 7b that are externally fitted to the rotary shaft 4 so as to be slidable and relatively rotatable by slide bearings 13a and 13b, and a carrier body 7a and a support plate 7b that are separated from each other. The support pin 7c for rotatably supporting the planetary roller 6 and a plurality of connecting rods 7d for connecting the support plate 7b in phase with the carrier body 7a are connected to both ends of the connecting rod 7d with bolts 7e. The main body 7a and the support plate 7b are connected. Each support pin 7c is attached to both ends thereof in a radial slot 14 provided in the carrier body 7a and the support plate 7b so that movement in the circumferential direction is restricted and movement in the radial direction is allowed. It has been.

  Grooves 15 are provided on the outer diameter surfaces of both end portions of each support pin 7c, and a reduced diameter ring spring 16 formed of spring steel with a part cut in the circumferential direction is fitted in each groove 15, Each support pin 7c is wound and attached so as to envelop. Therefore, each planetary roller 6 rotatably supported by each support pin 7c is pressed against the outer diameter surface of the rotating shaft 4, and the rotational torque of the rotating shaft 4 is stably transmitted to each planetary roller 6.

  Each planetary roller 6 is rotatably supported on a support pin 7c of a carrier 7 by a needle roller bearing 17 mounted on an inner diameter surface, and its rotation is supported by a carrier body 7a by a thrust roller bearing 18. On the front side of the carrier 7 that revolves together with each planetary roller 6 and linearly moves as an output member, a connecting member 19 that connects to the driven object is provided. A fan-shaped lubricant application member 20 that slidably contacts the outer diameter surfaces of the planetary rollers 6 on both sides and applies grease between the adjacent planetary rollers 6 is provided between the connecting rod 7 d of the carrier 7 and the outer ring member 5. It is held between the inner diameter surface.

  The connecting member 19 is externally fitted to the cylindrical portion of the carrier body 7a and is prevented from coming off by a retaining ring 21, and is supported by a thrust roller bearing 22 so as to be rotatable relative to the carrier body 7a, and is connected to a driven object. A key 23 for preventing rotation is provided on the front end face. The outer diameter side of the connecting member 19 is sealed between the cylindrical portion 1a of the housing 1 by an annular seal member 24, and the inner diameter side of the connecting member 19 is the rotational shaft 4 fitted in the carrier body 7a. It is sealed with a film-like sealing member 25 so as to cover the end.

  A spiral protrusion 5a is provided on the inner diameter surface of the outer ring member 5, and the spiral protrusion 5a is fitted on the outer diameter surface of the planetary roller 6, and a circumferential groove 6a having the same pitch as the spiral protrusion 5a is provided. It has been. By the engagement of the spiral ridges 5a and the circumferential grooves 6a, the planetary roller 6 that revolves while rotating around the rotation shaft 4 moves relative to the outer ring member 5 in the axial direction at the lead angle of the spiral ridges 5a. The carrier 7 as the output member also moves linearly together with the planetary roller 6. In this embodiment, when the carrier 7 moves forward so as to linearly drive the driven object, each planetary roller 6 is externally connected to each planetary roller 6 via each thrust roller bearing 18 disposed on the advance side of the carrier 7. Thrust load is applied.

  As shown in FIG. 4, the axial position of the spiral ridge 5a of the outer ring member 5 that fits into the circumferential groove 6a of each planetary roller 6 supported by the thrust roller bearing 18 is different in the revolving position in the circumferential direction. In this embodiment, the distance from the support end surface 6b of each planetary roller 6 supported by the thrust roller bearing 18 to a predetermined reference position of the circumferential groove 6a is set to a different size in this embodiment. The circumferential groove position is adjusted so that the axial positions of the spiral ridges 5a fitted into the respective circumferential grooves 6a are matched. Therefore, the thrust load from the outside is equally applied to each planetary roller 6.

  FIGS. 5A and 5B show a method of forming each planetary roller 6 for adjusting the circumferential groove position. First, as shown in FIG. 5 (a), a material for the planetary roller 6 having a circumferential groove 6a having the same pitch as the spiral ridge 5a formed on the outer diameter surface is prepared, and this material is scheduled to be cut. The measurement ball S is fitted in the circumferential groove 6a close to the position, and the distance d from the reference position to the support end surface 6b with the center of the measurement ball S as the reference position is different from each other for each planetary roller 6. In this manner, the material is cut at the support end surface 6b, and the end surface opposite to the support end surface 6b is cut so that the lengths in the axial direction of the planetary rollers 6 are the same.

  Thereafter, as shown in FIG. 5B, when an incompletely shaped circumferential groove 6a is formed on one end face side of the cut planetary roller 6, the end face side rises from the groove bottom. A chamfer 6c is applied to the outer diameter surface of the end so as to remove the rising portion of the incompletely shaped circumferential groove 6a. In this example, the chamfer 6c for removing the rising portion is provided on both ends, but the chamfer 6c may be provided on only one side or the chamfer 6c may not be provided on both sides depending on the cutting position with respect to the circumferential groove 6a.

  FIGS. 6A and 6B show modifications of the planetary roller 6 having different distances from the support end surface 6b to a predetermined reference position of the circumferential groove 6a. In the modified example (a), the center of the circumferential groove 6a formed closest to the support end surface 6b of the planetary roller 6 is used as a reference position, and a small diameter equal to or smaller than the groove bottom diameter of the circumferential groove 6a on the support end surface 6b side. A portion 6d is provided, the axial length of the small diameter portion 6d is changed, and the distance d from the reference position of each planetary roller 6 to the support end surface 6b is set to a different size. The axial direction of the small diameter portion 6d The length dimension is not more than the pitch of the circumferential groove 6a. In the modified example of (b), the small diameter portion 6d of the modified example of (a) is formed by a separate ring member 29.

  In each modification shown in FIGS. 6A and 6B, the axial length of each planetary roller 6 including the small diameter portion 6d or the ring member 29 is slightly different. No thrust load is applied to the opposite end surfaces, and axial gaps may be formed on these end surfaces, so the axial lengths of the planetary rollers 6 do not necessarily have to be the same.

  FIG. 7 shows an electric brake device that employs the electric linear actuator described above. This electric brake device is a disc brake in which a brake pad 33 as a brake member is disposed oppositely on both sides of a disc rotor 32 as a braked member inside the caliper body 31, and the electric linear actuator is connected to the caliper body 31. When the carrier 1 as the output member linearly moves to the left, the carrier 7 moves the brake pad 33 as the driven object against the load via the connecting member 19, and the disk rotor 32. It is designed to be pressed. In this figure, the electric linear actuator is shown in a cross section orthogonal to the cross section shown in FIG.

  8 and 9 show a second embodiment. This electric linear actuator is different from that of the first embodiment in that the movement of the carrier 7 in the axial direction is restricted and the outer ring member 5 is an output member that linearly moves. As shown in FIG. 8, in this embodiment, the carrier body 7a and the support plate 7b of the carrier 7 are disposed on the left and right sides opposite to those of the first embodiment, and the carrier body 7a is thrust through a support member 7f. A roller bearing 26 is supported by the shaft support member 8 fitted on the side of the lid 1c of the cylindrical portion 1a of the housing 1 so as to revolve freely. The shaft support member 8 is fixed on both sides in the axial direction by a retaining ring 10a, and the support plate 7b is prevented from being detached from the rotating shaft 4 by a retaining ring 28 via a slide bearing 27, so that movement of the carrier 7 in the axial direction is restricted. Has been.

  The outer ring member 5 as the output member is slidably fitted in the cylindrical portion 1a of the housing 1, and a key 23 that is connected to the driven object and prevents rotation is provided on the front end surface. The outer ring member 5 is sealed with an annular seal member 24 between the outer diameter side of the outer ring member 5 and the cylindrical portion 1 a, and the inner diameter side of the outer ring member 5 is fixed to the support plate 7 b of the carrier 7. It is sealed with a film-like sealing member 25 so as to cover the end. In this embodiment, when the outer ring member 5 moves forward so as to linearly drive the driven object, each planetary roller 6 is provided with a thrust roller bearing 18 disposed on the side opposite to the forward side of the outer ring member 5. Thus, an external thrust load is applied.

  As shown in FIG. 9, the axial position of the circumferential groove 6a of each planetary roller 6 is the circumferential groove of each planetary roller 6 supported by the thrust roller bearing 18 as in the first embodiment. Although the axial position of the spiral protrusion 5a of the outer ring member 5 fitted into 6a is slightly shifted due to the difference in the circumferential revolving position, as shown in FIG. 5 or FIGS. 6 (a) and 6 (b). The means for setting the distance from the support end surface 6b of each planetary roller 6 supported by each thrust roller bearing 18 to a predetermined reference position of the circumferential groove 6a to different dimensions fits with each circumferential groove 6a. The axial positions of the spiral ridges 5a coincide with each other.

  10 and 11 show a third embodiment. This electric linear actuator has the same basic configuration as that of the second embodiment, and the circumferential groove 6a of each planetary roller 6 and the spiral ridge 5a of the outer ring member 5 fitted therein. Only the circumferential groove position adjusting means for matching the axial positions of the two is different. In this embodiment, spacers 30 having different axial thicknesses are disposed between the raceway ring 18a of the thrust roller bearing 18 that supports the rotation of each planetary roller 6 and the carrier body 7a of the carrier 7, so that the revolution in the circumferential direction is performed. Adjustment is made so that the axial position of the spiral ridge 5a that is gradually shifted due to the difference in position coincides with the axial position of the circumferential groove 6a of each planetary roller 6 supported by the thrust roller bearing 18 for rotation. The spacer 30 can also be formed integrally with the race ring 18a or the carrier body 7a.

  In each of the above-described embodiments, the spiral protrusion on the inner surface of the outer ring member is integrally formed. However, a spiral groove is provided on the inner surface of the outer ring member, and the spiral protrusion is formed by a separate member fitted in the spiral groove. Can also be formed. Further, although the number of arranged planetary rollers is four, the number of arranged planetary rollers is not limited to four.

DESCRIPTION OF SYMBOLS 1 Housing 1a Cylindrical part 1b Flange 1c Lid 2 Electric motor 2a Rotor shaft 3a, 3b, 3c Gear 4 Rotating shaft 5 Outer ring member 5a Spiral ridge 6 Planetary roller 6a Circumferential groove 6b Support end face 6c Chamfer 6d Small diameter part 7 Carrier 7a Carrier Main body 7b Support plate 7c Support pin 7d Connecting rod 7e Bolt 7f Support member 8 Shaft support member 9 Ball bearing 10a, 10b, 10c Retaining ring 11 Shaft pin 12 Ball bearing 13a, 13b Slide bearing 14 Long hole 15 Groove 16 Reduced diameter ring spring 17 Needle roller bearing 18 Thrust roller bearing 18a Bearing ring 19 Connecting member 20 Lubricant application member 21 Retaining ring 22 Thrust roller bearing 23 Keys 24 and 25 Seal member 26 Thrust roller bearing 27 Sliding bearing 28 Retaining ring 29 Ring member 30 Spacer 31 Caliper body 32 Disc rotor 33 Brake pad

Claims (11)

  A plurality of planetary rollers rotatably supported by a carrier between a rotating shaft to which rotation is transmitted from a rotor shaft of an electric motor and an outer ring member fitted inside the inner diameter surface of the housing on the outer diameter side of the rotating shaft These planetary rollers revolve while rotating around the rotation shaft as the rotation shaft rotates, and provided with spiral ridges on the inner diameter surface of the outer ring member, A circumferential groove into which the spiral ridge is fitted at the same pitch as the spiral ridge is provided on the outer diameter surface, the outer ring member and the carrier are relatively moved in the axial direction, and the rotational movement of the rotating shaft is controlled by the carrier. In order to drive the driven object linearly, the rotation of each planetary roller is caused by the thrust bearing on the end face on the side where the thrust load is applied to the carrier that linearly drives the driven object. Supported by carrier In the above-described electric linear actuator, the axial position of the circumferential groove of each planetary roller supported by the thrust bearing coincides with the axial position of the spiral ridge of the outer ring member fitted in the circumferential groove. An electric linear motion actuator characterized in that circumferential groove position adjusting means for adjusting the position is provided.   A plurality of planetary rollers rotatably supported by a carrier between a rotating shaft to which rotation is transmitted from a rotor shaft of an electric motor and an outer ring member fitted inside the inner diameter surface of the housing on the outer diameter side of the rotating shaft These planetary rollers revolve while rotating around the rotation shaft as the rotation shaft rotates, and provided with spiral ridges on the inner diameter surface of the outer ring member, A circumferential groove into which the spiral ridges are fitted at the same pitch as the spiral ridges is provided on the outer diameter surface, the outer ring member and the carrier are relatively moved in the axial direction, and the rotational movement of the rotating shaft is controlled by the outer ring. The driven object is linearly driven by converting it into a linear motion of the member, and the rotation of each planetary roller is performed on the end surface opposite to the side on which the thrust load is applied to the outer ring member that linearly drives the driven object. The carrier by the thrust bearing The axial position of the circumferential groove of each planetary roller supported by the thrust bearing in the electric linear motion actuator supported by the thrust bearing, and the axial position of the spiral ridge of the outer ring member fitted into these circumferential grooves An electric linear motion actuator comprising a circumferential groove position adjusting means for adjusting so as to match with the motor.   The circumferential groove position adjusting means is arranged such that a distance from a support end surface supported by the thrust bearing of each planetary roller to a predetermined reference position of the circumferential groove is a spiral ridge that fits into the circumferential groove. 3. The electric linear actuator according to claim 1, wherein different dimensions are set so that the positions in the axial direction coincide with each other.   When the circumferential groove is formed over the entire axial length of each planetary roller and the distance from the support end surface to the predetermined reference position of the circumferential groove is set to a different dimension, any planetary roller The chamfering is performed so as to remove the rising portion of the incompletely shaped circumferential groove when the incompletely shaped circumferential groove rising from the groove bottom is formed on the end surface side of any of The electric linear actuator described.   Provided on the support end surface side of the circumferential groove formed closest to the support end surface of each planetary roller is a small diameter portion equal to or smaller than the groove bottom diameter of the circumferential groove, and the axial length of the small diameter portion is changed. 4. The electric linear actuator according to claim 3, wherein the distance from the support end face of each planetary roller to the reference position of the circumferential groove is set to a different size.   The electric linear actuator according to claim 5, wherein an axial length dimension of the small diameter portion is equal to or less than a pitch of the circumferential groove.   The electric linear actuator according to claim 5 or 6, wherein the small diameter portion is formed by a separate ring member.   3. The spacer according to claim 1, wherein the circumferential groove position adjusting means includes spacers having different axial thicknesses between the bearing ring of the thrust bearing that supports the planetary rollers and the carrier. Electric linear actuator.   The electric linear actuator according to claim 8, wherein the spacer is formed integrally with a bearing ring or a carrier of the thrust bearing.   The electric linear actuator according to claim 1, wherein the planetary rollers have the same length in the axial direction.   In the electric brake device that includes an electric linear motion actuator that linearly drives the brake member by converting the rotary motion of the electric motor into a linear motion of the output member, and presses the brake member that is linearly driven against the member to be braked, An electric brake device using the electric linear actuator according to any one of claims 1 to 10 as an electric linear actuator.

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