JP2017160981A - Planetary roller screw type linear motion mechanism and electrically-driven brake control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of component elements of a linear motion mechanism to simplify their assembly works and make a compact axial length.SOLUTION: Both ends of a roller shaft 47 for supporting several planetary rollers 49 between an outer diameter surface of a rotating shaft 34 and an inner diameter surface of an outer ring member 21 are supported between a pair of opposing disks 41a, 41b of a rotatably supported carrier 40 by roller shaft supporting parts 46a, 46b formed at a disk. Planetary rollers are auto-rotated and revolved through frictional contact with the rotating shaft by rotation of the rotating shaft, and the outer ring member is linearly moved in an axial direction through engagement between a peripheral groove 54 formed at the outer diameter surface of the planetary roller 49 and a spiral protrusion 53 arranged at the inner diameter surface of the outer ring member. A roller shaft supporting part 46a formed at a disc 41a placed at inner side of the carrier is defined as a non-opened taper hole. A raceway surface 60 is formed at an inner side surface of the inner disc, and a thrust bearing 56 is assembled between the opposing parts between the raceway surface and the shaft supporting member 35 to support the carrier in rotatable manner.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a planetary roller screw type linear motion mechanism used in an electric linear motion actuator capable of linearly driving a driven member such as a brake pad, and an electric brake device using the planetary roller screw type linear motion mechanism.

  Patent Document 1 discloses an electric linear motion actuator using a planetary roller screw type linear motion mechanism that converts a rotational motion of a rotor shaft of an electric motor into a linear motion of a driven member that is supported so as to be axially movable by a motion conversion mechanism. What has been described in the past is known.

  In the planetary roller screw type linear motion mechanism described in Patent Document 1, a plurality of planetary rollers are incorporated between a rotating shaft that is rotationally driven by an electric motor and an outer ring member, and the planetary roller is centered on the rotating shaft. A spiral formed on the outer diameter surface of the planetary roller, which is rotatably supported by a carrier that is rotatably supported, and revolves while the planetary roller rotates by frictional contact with the rotation shaft. The outer ring member or the carrier is relatively linearly moved in the axial direction by meshing between the groove or the circumferential groove and the spiral protrusion provided on the inner diameter surface of the outer ring member.

  Further, when supporting each of the plurality of planetary rollers, both end portions of a support shaft that rotatably supports each planetary roller are inserted into radially long slots formed in a pair of opposed disks of the carrier, and the slots A diameter-reduced spring (C-shaped ring) is stretched over both ends protruding from the surface, the support shaft is urged radially inward, and each planetary roller is pressed against the rotation shaft, and the planet is rotated by rotation of the rotation shaft. The roller is reliably rotated in contact.

  In the planetary roller screw type linear motion mechanism, the outer ring member or the carrier is linearly moved relatively in the axial direction by the meshing of the spiral groove or circumferential groove provided on the planetary roller and the spiral protrusion provided on the outer ring member. Therefore, it is possible to ensure a large boosting function without separately installing a planetary gear type reduction mechanism, and it is suitable for use in an electric brake device with a relatively small linear motion stroke. ing.

JP 2010-90959 A

  Incidentally, in the planetary roller screw type linear motion mechanism described in Patent Document 1, in order to smoothly rotate the carrier, the carrier is rotatably supported by a thrust bearing. Therefore, the carrier disk cannot be directly rotatably supported by the thrust bearing, and it is necessary to incorporate a support member. For this reason, the number of parts is increased, and it takes time to assemble, and the length in the axial direction also becomes long. There are still points to be improved in order to facilitate the assembly and make the axial length compact.

  In addition, since it is necessary to provide a boss for supporting the support member on one of the disks of the carrier, the shape of the disk becomes complicated, which takes time to manufacture, and points that should be improved in order to facilitate the manufacture of the disk. Is left.

  An object of the present invention is to reduce the number of parts of a linear motion mechanism, to facilitate assembly and to reduce the axial length.

  In order to solve the above-described problems, in the present invention, a cylindrical outer ring member is slidably incorporated in a housing, and a rotary shaft that is rotationally driven by an electric motor is provided on the axis of the outer ring member. A plurality of planetary rollers are incorporated between the outer diameter surface of the rotation shaft and the inner diameter surface of the outer ring member between a pair of opposed disks of a carrier supported rotatably around the roller shaft, and each planetary roller is rotatably supported. A shaft support member that is supported by a roller shaft support portion formed on the disk, and that is incorporated in the housing and rotatably supports a shaft end portion on the torque input side of the rotating shaft, and the carrier. A thrust bearing that rotatably supports the carrier is incorporated between the opposed portions of the inner disk located on the shaft support member side, and frictional contact with the rotating shaft is achieved by rotation of the rotating shaft. To rotate and revolve the planetary roller, and move the outer ring member in the axial direction by meshing the spiral groove provided on the inner diameter surface of the outer ring member with the circumferential groove or the spiral groove formed on the outer diameter surface of the planetary roller. In the planetary roller screw type linear motion mechanism, the roller shaft support portion formed on the inner disk of the carrier is formed as a non-penetrating taper hole, and the inner circumference of the taper hole on the side away from the rotation shaft is uniform. The shaft end portion of the roller shaft is brought into pressure contact with the inner portion, and the inner disk is provided with a raceway surface for rolling and guiding the rolling element of the thrust bearing.

  As described above, the roller shaft support portion formed on the inner disk of the carrier is formed as a non-through tapered hole, so that the rolling element of the thrust bearing is placed on the surface facing the shaft support member of the inner disk. It is possible to form a raceway surface for rolling and guiding, and it is possible to eliminate the need for incorporating a support member, which has been conventionally required.

  In addition, by providing a raceway surface that rolls and guides the rolling elements on the surface facing the shaft support member of the inner side disk, the inner side disk also serves as a thrust bearing washer. The score can be reduced.

  Further, by pressing the shaft end of the roller shaft against a part of the inner periphery of the tapered hole on the side away from the rotating shaft, the planetary roller is pressed against the outer diameter surface of the rotating shaft by the reaction force caused by the pressing. Thus, the planetary roller can be reliably rotated in contact with the rotating shaft. The taper hole only needs to have a shape capable of obtaining a reaction force due to pressure contact, may have a stepped diameter reduction shape, and may not be in contact with the inner circumference on the side close to the rotation axis, and may have a straight shape or other shapes. . In other words, it is sufficient that the surface with which the roller shaft abuts at least on the inner circumference away from the rotation shaft is reduced in diameter toward the hole bottom.

  Here, it is preferable that a column hole for connecting a column member that maintains an opposing distance between the inner side disk and the outer side disk in the carrier is provided, and the column hole is a non-penetrating blind hole.

  As described above, by making the connecting column hole of the column member a blind hole, the column member does not appear on the surface facing the shaft support member on the inner disk, so the column member is a rolling element of a thrust bearing. The trajectory of rolling is not obstructed and can be set to an appropriate trajectory radius. Further, the inner disk has a simple shape in which a blind hole is formed on one surface of the annular plate, and can be manufactured by plastic working by press working or forging, so that the production cost can be reduced.

  Also, the roller shaft support part formed on the disk on the outer side of the carrier has a long hole in the radial direction, and a C-shaped elastic ring is hung so as to wrap the shaft end part of the roller shaft facing the outside from the long hole. It is preferable that the roller shaft is brought into pressure contact with the inner surface of the planetary roller via a bearing. At this time, the axial movement of the roller shaft and the elastic ring is performed by attaching a thrust washer which is coaxial with the rotation shaft at the shaft end portion of the rotation shaft and whose outer edge is larger than at least a common circumscribed circle passing through each roller shaft. It is good to regulate.

  As described above, the C-shaped elastic ring is stretched over the shaft end of the roller shaft, and the roller shaft is brought into pressure contact with the inner diameter surface of the planetary roller via the bearing, whereby the planetary roller is rotated over the entire length in the axial direction. The planetary roller can be contacted and rotated more reliably on the rotating rotating shaft. In addition, a thrust washer that is coaxial with the rotary shaft at the shaft end and whose outer edge is at least larger than a common circumscribed circle passing through each roller shaft is attached to restrict movement of the roller shaft and the elastic ring in the axial direction. By doing so, it is possible to reliably maintain the pressure contact state of the planetary roller with respect to the rotating shaft, and to eliminate the need for a retaining groove for retaining the C-shaped elastic ring at the shaft end of the roller shaft.

  In the electric brake device according to the present invention, the brake pad is linearly driven by the electric linear actuator using the planetary roller screw type linear movement mechanism, the disc rotor is pressed by the brake pad, and the braking force is applied to the disc rotor. In the electric brake device provided with the above-described configuration, a configuration using the planetary roller screw type linear motion mechanism according to the present invention is adopted as the planetary roller screw type linear motion mechanism.

  In the planetary roller screw type linear motion mechanism according to the present invention, as described above, the roller shaft support portion formed on the inner disk of the carrier is a non-penetrating taper hole, and the roller shaft support comprising the taper hole is provided. By supporting the one end portion of the roller shaft by this portion, the thrust bearing can be supported by the outer end surface of one of the disks, and the support member that has been conventionally required can be dispensed with. In addition, by providing a raceway surface for rolling and guiding the rolling element of the thrust bearing on the outer end face of one of the disks, one thrust washer is not required on the thrust bearing side, and assembly is facilitated by reducing the number of parts. be able to. Further, the axial length can be reduced.

A longitudinal sectional view showing an embodiment of an electric linear actuator incorporating a planetary roller screw linear motion mechanism according to the present invention FIG. 1 is an enlarged sectional view showing the vicinity of the planetary roller screw type linear motion mechanism of FIG. Sectional view along line III-III in FIG. Sectional view along line IV-IV in FIG. Sectional drawing which expands and shows a part of FIG. Sectional view showing another example of thrust bearing A longitudinal sectional view showing an embodiment of an electric brake device according to the present invention Right side view of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 5 show an electric linear actuator A that incorporates a planetary roller screw type linear movement mechanism that is employed in the electric brake device shown in FIGS. 7 and 8.

  In the electric brake device shown in FIGS. 7 and 8, a caliper 11 is provided on the outer periphery of the disc rotor 10 that rotates integrally with a wheel (not shown), and an outer peripheral portion of the outer side surface of the disc rotor 10 is provided at one end portion of the caliper 11. The claw part 12 which opposes in an axial direction is provided, and the outer side brake pad 13 is supported by the claw part 12.

  Further, an inner brake pad 14 is disposed opposite to the outer peripheral portion of the inner side surface of the disk rotor 10, and the inner brake pad 14 is attached to the disk rotor 10 by an electric linear actuator A provided on the other side of the caliper 11. I try to move it.

  The mount 15 is supported by a knuckle (not shown), and is fixed to the outer periphery of the disk rotor 10 so as not to move in the axial direction. A pair of opposed pin support pieces 16 are provided on both sides of the mount 15, and slide pins 17 extending in a direction orthogonal to the disk rotor 10 are provided at the respective ends of the pin support pieces 16. The caliper 11 is slidably supported by each.

  Although not shown in detail in the figure, the mount 15 is supported so as to be movable toward the disc rotor 10 in a state in which each of the outer brake pad 13 and the inner brake pad 14 is non-rotatable. doing.

  As shown in FIG. 1, the electric linear actuator A has a housing 20. The housing 20 is integrally provided with the caliper 11 shown in FIG. 7 to form a cylinder, and a cylindrical outer ring member 21 is slidably incorporated therein.

  A base plate 22 is provided radially outward at the inner end of the housing 20 away from the disk rotor 10 (see FIG. 7). The outer surface of the base plate 22 and one end opening of the housing 20 are covered by the cover 23. The base plate 22 and the cover 23 form a gear case.

  An electric motor 24 is supported on the base plate 22, and the rotation of the rotor shaft 25 of the electric motor 24 is decelerated and output by a gear reduction mechanism 30 in a gear case formed by the base plate 22 and the cover 23.

  As shown in FIGS. 1 and 8, the gear reduction mechanism 30 includes an input gear 31 attached to the rotor shaft 25 of the electric motor 24, an intermediate gear 32 that meshes with the input gear 31, and a mesh with the intermediate gear 32. The outer diameter of the output gear 33 is larger than the outer diameter of the input gear 31.

  As shown in FIG. 1, the output gear 33 is supported at the inner shaft end of the rotating shaft 34. The rotating shaft 34 passes through a shaft support member 35 incorporated in the inner end portion of the housing 20, and the shaft end portion on the torque input side is rotatably supported by a plurality of bearings 36 incorporated in the penetrating portion. It is arranged on the axial center of the outer ring member 21.

  Here, the shaft support member 35 is press-fitted into the inner diameter surface of the housing 20 and is positioned in the axial direction by a retaining ring 37 attached to the inner diameter surface of the housing 20. Reference numeral 38 denotes a circumferential groove for attaching the retaining ring 37. Further, the shaft support member 35 is provided with a circular bulging portion 35 a having a size that can be inserted into the outer ring member 21 on the outer side surface facing the outer ring member 21.

  As shown in FIGS. 1 and 2, a carrier 40 that is rotatable within the outer ring member 21 around the rotation shaft 34 is incorporated on the rotation shaft 34. As shown in FIGS. 2 and 3, the carrier 40 includes a pair of annular disks 41 a and 41 b that face each other in the axial direction, and a plurality of round shaft-shaped column members that maintain a constant interval between the disks 41 a and 41 b. 42.

  In each of the pair of disks 41a and 41b, a plurality of a pair of column holes 43a and 43b opposed in the axial direction are formed at equal intervals in the circumferential direction. Here, the column hole 43a formed in the inner disk 41a is a blind hole. On the other hand, the column hole 43b formed in the outer side disk 41b is a through-hole penetrating from one side surface to the other side surface, and both ends of the column member 42 are press-fitted into the respective column holes 43a and 43b to assemble the carrier 40. It is said that.

  Here, as shown in FIG. 3, the number of column members 42 is four, and the four column members 42 are provided at intervals of 90 ° in the circumferential direction, but the number of the column members 42 is four. It is not limited to, and it is sufficient that there are at least three or more.

  As shown in FIG. 2, the carrier 40 is rotatably supported around a rotating shaft 34 by a slide bearing 44 incorporated in each of the inner diameter surfaces of the pair of disks 41 a and 41 b, and the shaft end of the rotating shaft 34. The retaining ring 45 attached to the section prevents the shaft from rotating from the shaft end.

  Each of the pair of disks 41a and 41b in the carrier 40 is formed with a pair of roller shaft support portions 46a and 46b opposed in the axial direction at intervals in the circumferential direction, and the pair of roller shaft support portions 46a and 46b facing each other. These support the shaft end of the roller shaft 47. Each roller shaft 47 is fitted with a pair of bearings 48, and planetary rollers 49 are rotatably supported by the bearings 48.

  Here, the roller shaft support portion 46a formed on the inner disk 41a has a non-through tapered hole, and the shaft end of the roller shaft 47 is formed on a part of the inner periphery of the taper hole 46a on the side away from the rotation shaft 34. A radial gap 50 is provided at a position that is 180 ° circumferentially deviated from the pressure contact portion, and is caused by a reaction force caused by the pressure contact of the shaft end portion of the roller shaft 47 against the inner periphery of the tapered hole 46a. The inner end of the planetary roller 49 is in pressure contact with the outer diameter surface of the rotating shaft 34.

  On the other hand, the roller shaft support 46b formed on the outer disk 41b is a long hole in the radial direction, and the shaft end of the roller shaft 47 is slidably inserted into the long hole 46b.

  A C-shaped elastic ring 51 (see FIG. 4) is wrapped around the shaft end portion facing the outside from the long hole 46b of the roller shaft 47 so as to wrap the shaft end portions of the plurality of roller shafts 47. The planetary roller 49 is in pressure contact with the outer diameter surface of the rotating shaft 34 over the entire length in the axial direction by the elastic force of 51 in the diameter reducing direction.

  As described above, when the planetary roller 49 is brought into pressure contact with the outer diameter surface of the rotating shaft 34 over the entire length in the axial direction, the planetary roller 49 can be reliably rotated by the rotation of the rotating shaft 34.

  A thrust washer 52 is attached to the shaft end of the rotating shaft 34. The thrust washer 52 is provided with a cylindrical portion 52b on the outer peripheral portion of the disc portion 52a that is incorporated between the facing portions of the retaining ring 45 and the outer disk 41b, and has a large-diameter circle facing outward at the end of the cylindrical portion 52b. The plate portion 52c is continuously provided, and the large-diameter cylindrical portion 52d is continuously provided on the outer periphery of the large-diameter disc portion 52c. The large-diameter disc portion 52c faces the shaft end surface of the roller shaft 47, and The movement of the roller shaft 47 in the axial direction is restricted, and the large-diameter cylindrical portion 52d faces the elastic ring 51 in the axial direction to restrict the movement of the elastic ring 51 in the axial direction.

  As shown in FIGS. 2 and 3, a plurality of circumferential grooves 54 are formed on the outer diameter surface of the planetary roller 49 at the same pitch as the pitch of the spiral protrusions 53 having a V-shaped cross section provided on the outer ring member 21. The spiral protrusion 53 is engaged with the circumferential groove 54 formed. Instead of the circumferential groove 54, a spiral groove having a lead angle different from that of the spiral protrusion 53 may be formed.

  Of the pair of disks 41 a and 41 b in the carrier 40, a thrust retainer roller-attached 55 is incorporated between the opposed parts of the inner disk 41 a located on the shaft support member 35 side and the plurality of planetary rollers 49.

  An end surface 49a of the planetary roller 49 facing the roller 55 with thrust retainer is a raceway surface, and the roller 55 with thrust retainer is rolled and guided by the raceway surface 49a. The raceway surface 49a is heat-treated to increase its hardness. The raceway surface 49a is polished so that the surface roughness Ra is 0.2 or less.

  As shown in FIGS. 1 and 2, a thrust bearing 56 is incorporated between the circular bulging portion 35 a of the shaft support member 35 that rotatably supports the inner disk 41 a and the rotation shaft 34 in the carrier 40. .

  As shown in FIG. 5, the thrust bearing 56 includes a washer disk 57 supported by the circular bulging portion 35 a of the shaft support member 35, a plurality of rolling elements 58 that can roll along the washer disk 57, and The inner surface disc 41a of the carrier 40 is provided with a raceway surface 60 for rolling and guiding the rolling member 58. The thrust bearing 56 supports an axial reaction force applied to the carrier 40 from the outer ring member 21 via the planetary roller 49.

  The inner disk 41a in the carrier 40 is formed by plastic working. The plastic working may be forging or press working. The inner side disk 41 a is heat treated and has a guide layer for guiding the roller 55 with a thrust cage and a hardened layer on the surface layer portion of the raceway surface 60. The surface layer portion is polished to have a surface roughness Ra of 0.2 or less.

  As shown in FIG. 7, a cover 61 is fitted in the outer side end portion of the outer ring member 21. An anti-rotation groove 62 is formed on the front end surface of the outer ring member 21, and the outer ring member 21 is engaged with the inner side brake by engagement of the anti-rotation groove 62 and the anti-rotation protrusion 19 provided on the back plate 18 of the inner brake pad 14. It is prevented from rotating with respect to the pad 14.

  A boot 63 is attached between the outer side end of the housing 20 and the outer ring member 21, and the boot 63 seals between the outer end of the housing 20 and the tip of the outer ring member 21.

  The electric brake device shown in the embodiment has the above-described configuration. FIG. 7 shows a state where the braking force is released from the disk rotor 10, and the pair of brake pads 13 and 14 are separated from the disk rotor 10.

  When the electric motor 24 shown in FIG. 1 is driven in the state in which the braking force is released as described above, the rotation of the rotor shaft 25 of the electric motor 24 is decelerated by the gear reduction mechanism 30 and transmitted to the rotating shaft 34, and the rotating shaft 34 rotates in the braking direction.

  Since the outer diameter surfaces of the plurality of planetary rollers 49 are in elastic contact with the outer diameter surface of the rotating shaft 34, the planetary roller 49 is rotated by contact friction with the rotating shaft 34 when the rotating shaft 34 is rotated. The revolution 40 causes the carrier 40 to rotate about the rotation shaft 34.

  At this time, since the circumferential groove 54 formed on the outer diameter surface of the planetary roller 49 meshes with the spiral protrusion 53 provided on the inner diameter surface of the outer ring member 21, the circumferential groove 54 and the spiral protrusion 53. , The outer ring member 21 and the planetary roller 49 move relative to each other in the axial direction. However, since the planetary roller 49 is restricted from moving in the axial direction together with the carrier 40, the planetary roller 49 is axially moved relative to the housing 20. The outer ring member 21 moves in the axial direction with respect to the housing 20 without moving. Then, as shown in FIG. 7, the inner brake pad 14 in contact with the outer ring member 21 comes into contact with the disk rotor 10 and starts to press the disk rotor 10 in the axial direction. The caliper 11 moves toward the direction in which the outer brake pad 13 supported by the claw portion 12 approaches the disc rotor 10 by the reaction force of the pressing force, and the outer brake pad 13 contacts the disc rotor 10, The outer brake pad 13 strongly clamps the outer periphery of the disk rotor 10 from both sides in the axial direction with the inner brake pad 14, and a braking force is applied to the disk rotor 10.

  When the braking force is applied as described above, an axial load is applied from the outer ring member 21 to the planetary roller 49, and the axial load is supported by the inner disk 41a of the carrier 40 via the roller 55 with a thrust cage. The planetary roller 49 always rotates smoothly.

  Further, the axial load applied to the inner disk 41 a of the carrier 40 through the planetary roller 49 and the roller 55 with thrust cage is supported by the shaft support member 35 through the thrust bearing 56. For this reason, the carrier 40 rotates smoothly around the rotation shaft 34.

  When the rotor shaft 25 of the electric motor 24 shown in FIG. 1 is reversely rotated after the disk rotor 10 is braked, the rotating shaft 34 is decelerated and rotated in the reverse direction to that described above, and the circumferential groove 54 of the planetary roller 49 that revolves while rotating. The outer ring member 21 is moved backward to the position shown in FIG. 7 by the meshing of the spiral protrusions 53, the outer brake pad 13 and the inner brake pad 14 release the clamping of the disc rotor 10, and the braking force is released. The

  In the electric linear actuator A shown in the embodiment, as shown in FIG. 2, the roller shaft support portion 46a formed on the inner disk 41a of the carrier 40 is formed as a non-through tapered hole, and the column Since the connecting column hole 43a of the member 42 is a non-penetrating blind hole, a raceway surface 60 that rolls and guides the rolling element 58 of the thrust bearing 56 is formed on the axial end surface of the inner disk 41a. It is possible to eliminate the need for incorporating the support member described in the prior art document.

  Further, by providing a raceway surface 60 that rolls and guides the rolling elements 58 on the outer end face of the inner side disc 41 a, the inner side disc 41 a also serves as a raceway for the thrust bearing 56. Can eliminate the need for a single washer.

  As described above, since the support member and the washer can be omitted, the number of parts can be reduced and the assembly can be facilitated. Further, the axial length can be reduced.

  Moreover, the inner side disk 41a becomes a simple shape by making the roller shaft support portion 46a into a non-through tapered hole and the connecting column hole 43a of the column member 42 into a non-penetrating blind hole. And can be easily manufactured by plastic working by forging.

  In FIG. 5, as the thrust bearing 56, the rolling element 58 is composed of rollers, but is not limited thereto. For example, as shown in FIG. 6, the rolling element 58 may be a thrust bearing made of balls. In this case, a raceway surface 60 made of a raceway groove is provided on the raceway disk 57 and the inner disk 41a.

  1, 2, and 5, the inner disk 41 a of the carrier 40 is provided with a raceway surface 60 that rolls and guides the rolling element 58 of the thrust bearing 56. Alternatively, the raceway surface 57 may be eliminated by forming a raceway surface similar to the raceway surface 60 on the circular bulging portion 35 a of the shaft support member 35 that supports the raceway disc 57. The same applies to the embodiment of FIG.

A Electric linear actuator 10 Disc rotor 13, 14 Brake pad 20 Housing 21 Outer ring member 24 Electric motor 34 Rotating shaft 35 Shaft support member 40 Carrier 41a Inner side disc 41b Outer side disc 42 Column member 43a Column hole (blind hole) )
46a Roller shaft support (taper hole)
46b Roller shaft support (long hole)
49 planetary roller 51 elastic ring 52 thrust washer 53 spiral ridge 54 circumferential groove 56 thrust bearing 60 raceway surface

Claims (5)

A cylindrical outer ring member is slidably incorporated in the housing, a rotation shaft is provided on the axis of the outer ring member, and a rotation shaft is provided between a pair of opposed disks of a carrier supported rotatably about the rotation axis. A plurality of planetary rollers are incorporated between the outer diameter surface of the outer ring member and the inner diameter surface of the outer ring member, and both end portions of a roller shaft that rotatably supports each planetary roller are supported by roller shaft support portions formed on the disk, and the housing The carrier is freely rotatable between a shaft support member that is incorporated in the shaft and rotatably supports the torque input side shaft end portion of the rotating shaft, and an inner side disk located on the shaft support member side of the carrier. A thrust bearing provided on the inner diameter surface of the outer ring member, in which a thrust bearing to be supported is incorporated, and the rotation of the rotating shaft causes the planetary roller to rotate and revolve by frictional contact with the rotating shaft. In the planetary roller screw linear motion mechanism so as to move the outer ring member in the axial direction by meshing of the formed on the outer diameter surface circumferential groove or a spiral groove of the planetary rollers,
The roller shaft support portion formed on the inner disk of the carrier is formed as a non-penetrating taper hole, and the shaft end of the roller shaft is pressed against a part of the inner periphery of the taper hole on the side away from the rotation shaft. A planetary roller screw type linear motion mechanism, wherein a raceway surface for rolling and guiding a rolling element of the thrust bearing is provided on the inner disk.   The inner disk of the carrier is provided with a column hole for connecting a column member that maintains a facing interval between the inner disk and the outer disk, and the column hole is a non-penetrating blind hole. Planetary roller screw type linear motion mechanism.   The roller shaft support portion formed on the disk on the outer side of the carrier is a long hole in the radial direction, and a C-shaped elastic ring is hung so as to wrap the shaft end portion of the roller shaft facing the outside from the long hole. 3. The thrust washer according to claim 1, wherein the planetary roller is brought into pressure contact with the outer diameter surface of the roller shaft, and a thrust washer for restricting movement of the roller shaft and the elastic ring in the axial direction is attached to an end portion of the rotating shaft. Planetary roller screw type linear motion mechanism.   An electric linear actuator comprising the planetary roller screw type linear motion mechanism according to any one of claims 1 to 3 and an electric motor that rotationally drives the rotary shaft. In the electric brake device in which the brake pad is linearly driven by the electric linear actuator, the disc rotor is pressed with the brake pad, and the braking force is applied to the disc rotor.
The electric brake device, wherein the electric linear actuator comprises the electric linear actuator according to claim 4.

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