JP6700064B2 - Electric linear actuator and electric brake device - Google Patents

Description

  The present invention relates to an electric linear motion actuator that linearly drives a driven member such as a brake pad, and an electric brake device using the electric linear motion actuator.

  BACKGROUND ART As an electric linear motion actuator that linearly drives a brake pad in an electric brake device, the one described in Patent Document 1 is conventionally known. In the electric linear motion actuator described in Document 1, one end of the gear case is connected to the inner side end of the caliper housing in which the linear motion member for pressing the brake pad is incorporated, and one end of the gear case is connected. The rotation of the rotor shaft serving as the output shaft of the electric motor supported at the other end is reduced by the gear reduction mechanism incorporated in the gear case, and the rotation of the output gear of the gear reduction mechanism is converted by the motion conversion mechanism into the linear motion member. The linear motion of the brake pad is pressed against the brake disc by the linear motion member.

  Here, as a gear reduction mechanism incorporated in the gear case, the rotation of the input gear attached to the output shaft of the electric motor is transmitted to the first idle gear to perform primary deceleration, and is provided coaxially with the first idle gear. A parallel shaft type gear reduction mechanism is adopted in which the second idle gear is transmitted to the output gear to perform secondary reduction and output.

  In the parallel shaft type gear reduction mechanism as described above, in order to rotate the gear smoothly, both ends of the gear are rotatably supported by rolling bearings. Swings around, causing vibration and noise, and it becomes impossible to smoothly transmit torque.

  The above inconvenience can be eliminated by applying a preload to the rolling bearing. Here, as a method of applying a preload to a rolling bearing that rotatably supports a gear, a method of applying a preload using an elastic member such as a coil spring or a disc spring is known.

  Further, as described in Patent Document 2, there is also a method in which a screw member is screwed into a screw hole formed in a gear housing, and the outer ring of the rolling bearing is pressed by the screwing of the screw member to apply a preload. Known from the past.

JP, 2005-52341, A JP, 2003-154945, A

  By the way, in a method of applying a preload to a rolling bearing by using an elastic member or a screw member, the number of parts is increased, which is disadvantageous in cost, and it takes time and effort to assemble the gear reduction device. Since it is necessary to secure a space for incorporating the device, there is a disadvantage that the device becomes large.

  An object of the present invention is to provide a rolling bearing that rotatably supports a gear of a gear speed reducer, which is capable of applying a preload without increasing the number of parts, and which is cost-effective and can be downsized by an electric direct drive. It is to provide an actuator.

  In order to solve the above problems, in an electric linear actuator according to the present invention, an electric motor, a gear reduction device that decelerates and outputs rotation of an output shaft of the electric motor, and an output from the gear reduction device. The gear reduction device includes a motion conversion mechanism that converts the rotational motion of the rotating member that is rotated by rotation into the linear motion of the linear motion member, and the gear reduction device includes a gear case and a parallel shaft type gear reduction mechanism incorporated in the gear case. In the electric linear actuator having, the gear case is composed of a case body having a peripheral wall provided on an outer peripheral surface of one surface of the base plate, and a lid body welded to an opening end of the peripheral wall of the case body, Each of the base plate and the lid is provided with a bearing fitting portion at a position facing the gear of the gear reduction mechanism, and a rolling bearing for rotatably supporting the gear is incorporated in the bearing fitting portion, and the bearing on the lid side The fitting portion is provided with a pressing step portion that presses one of the inner and outer races of the rolling bearing in the welded state of the lid.

  As described above, the bearing fitting portion provided on the lid body is provided with the pressing step portion that presses one of the inner and outer races of the rolling bearing in the welded state of the lid body. By fixing the lid body by ultrasonic welding, which is for welding the lid body, the pressing step portion presses one of the inner and outer races of the rolling bearing to apply a preload to the rolling bearing.

  Here, each of the base plate and the lid body is provided with a stepped hole, the large diameter hole portion of the stepped hole serves as a bearing fitting portion, and the bottom portion of the large diameter hole portion of the lid side stepped hole serves as a pressing step portion. Alternatively, a stepped shaft portion may be provided on each of the base plate and the lid, and the small diameter shaft portion of the stepped shaft portion may be used as a bearing fitting portion, and the step of the base of the small diameter shaft portion of the lid side stepped shaft portion may be used. The part may be a pressing step part.

  In the electric linear actuator according to the present invention, since the case body and the lid are welded by ultrasonic welding as described above, the case body and the lid are made of resin. In this case, a lid fitting recess that allows the lid to be fitted is provided on the inner circumference of the opening end of the peripheral wall of the case body, and a tapered surface is formed at the bottom of the lid fitting recess, and the lid fitting recess is formed on the outer circumference of the lid. Is preferably provided with an annular edge that contacts the tapered surface, and the contact portion between the annular edge and the tapered surface is welded. By welding the contact portion between the annular edge and the tapered surface, the lid can be effectively ultrasonically welded.

  In the electric brake device according to the present invention, the brake pad is linearly driven by the electric linear actuator, the brake disc is pressed by the brake pad, and the braking force is applied to the brake disc. The electric linear actuator according to the present invention is adopted as the electric linear actuator, and the brake pad is linearly driven by the linear member of the electric linear actuator.

  In the present invention, as described above, since the bearing fitting portion provided on the lid body is provided with the pressing step portion for pressing one of the inner and outer races of the rolling bearing in the welded state of the lid body, It is possible to apply a preload to the rolling bearing by ultrasonically welding the lid to the case body with the rolling bearing that is rotatably supported installed, and to apply the preload to the rolling bearing without increasing the number of parts. ..

  Further, since it is not necessary to assemble preload applying parts such as elastic members and screw members, the cost can be reduced and the assembly of the gear reduction device can be facilitated, and the preload applying parts can be assembled. Since it is not necessary to secure a space, the gear reducer can be downsized.

FIG. 4 is a vertical cross-sectional view showing an embodiment of an electric brake device adopting the electric linear actuator according to the present invention. Cross section of electric linear actuator Sectional view taken along line III-III in FIG. Sectional view taken along line IV-IV in FIG. Gear reducer cross section Sectional drawing which shows the welding part of the cover body shown in FIG. Sectional drawing which expands and shows the support part of the output gear of FIG. Sectional drawing which shows the other example of the support part of an output gear. Schematic diagram of ultrasonic welding machine

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 3, the electric brake device includes a brake disc 10 that rotates integrally with a wheel (not shown), and a caliper 11 provided on the outer periphery of the brake disc 10.

  The caliper 11 has a structure in which a claw portion 13 axially opposed to the outer peripheral portion of the outer side surface of the brake disc 10 is provided at the outer end of a cylindrical caliper housing 12 arranged on the inner side of the brake disc 10. The outer brake pad 14 is supported by the claw portion 13. The inner side of the vehicle body with the electric brake device attached to the vehicle body is called the inner side, and the side surface of the vehicle body is called the outer side.

  Inner side brake pads 15 are arranged opposite to each other on the outer peripheral portion of the inner side surface of the brake disc 10, and the inner side brake pads 15 are moved toward the brake disc 10 by an electric linear actuator 20 provided in the caliper housing 12. It

  A mount 16 is provided on the outer peripheral portion of the inner side surface of the brake disc 10. The mount 16 is fixed to a knuckle (not shown), and as shown in FIG. 3, a pair of opposed pin support pieces 17 provided on both sides of the mount 16 are provided with slide pins 18 extending in a direction orthogonal to the brake disc 10. The caliper 11 is slidably supported by each of the slide pins 18.

  Further, although not shown in detail in the drawing, the mount 16 is movably supported toward the brake disc 10 in a state in which the outer side brake pad 14 and the inner side brake pad 15 are non-rotatable (stop). is doing.

  As shown in FIG. 1, the electric linear motion actuator 20 has an outer ring member 21 as a linear motion member incorporated in a caliper housing 12 as a housing. The outer ring member 21 has a cylindrical shape, and the opening at the outer end is closed by attaching a cap 22. The outer ring member 21 is slidably supported in the axial direction by the caliper housing 12, and is prevented from rotating with respect to the inner brake pad 15 as described later.

  As shown in FIG. 2, a shaft support member 23 is incorporated inside the caliper housing 12 inside the inner side end of the outer ring member 21. The shaft support member 23 has a disk shape, and a boss portion 23a protruding toward the outer ring member 21 side is provided in the center thereof.

  An inward flange 24 is provided at an inner end of the caliper housing 12 on the vehicle body side, and the inward flange 24 prevents the shaft support member 23 from coming out of the inner end of the caliper housing 12.

  A pair of rolling bearings 25 are incorporated in the boss portion 23a of the shaft supporting member 23 at intervals in the axial direction, and the rolling bearings 25 serve as a rotating shaft 26 as a rotating member arranged on the axial center of the outer ring member 21. Is rotatably supported.

  As shown in FIG. 2, a rotary drive device 30 that drives the rotary shaft 26 is provided at the inner end of the caliper housing 12. The rotation driving device 30 includes an electric motor 31 and a gear reduction device 33 that decelerates and outputs the rotation of the output shaft 32 of the electric motor 31.

  As shown in FIGS. 2 and 3, the gear reduction device 33 includes a gear case 34 and a gear reduction mechanism 45 housed in the gear case 34. The gear case 34 includes a case body 35 having a peripheral wall 37 provided on the outer peripheral surface of one surface of a base plate 36, and a lid body 38 that closes an end opening of the peripheral wall 37 of the case body 35. The lid body 38 and the case Each of the main bodies 35 is made of resin.

  The base plate 36 of the case main body 35 is provided with a spigot protrusion 39 on the rear surface side with respect to the peripheral wall 37, and the spigot protrusion 39 is provided on the inner side end of the caliper housing 12. Is fitted inside. Due to the fitting, one end of the base plate 36 abuts against the opening end face of the inner side end of the caliper housing 12, and the bolt 40 screwed into the opening end face is tightened to attach the base plate 36 to the inner side end of the caliper housing 12. One end of is fixed.

  As shown in FIGS. 5 and 6, a lid fitting recess 41 is provided on the inner periphery of the opening end of the peripheral wall 37 of the case body 35, and a tapered surface 42 is provided on the bottom of the lid fitting recess 41. It is provided. On the other hand, a fitting protrusion 43 is provided on the outer peripheral portion of one surface of the lid 38, and the fitting protrusion 43 is fitted into the lid fitting recess 41 of the case body 35 to form an end surface of the fitting protrusion 43. An outer peripheral annular edge 44 abuts the tapered surface 42, and the edge contact portion is welded by ultrasonic welding to be integrated with the case body 35. A chain line a in FIG. 6 indicates an annular edge before welding.

  Here, FIG. 9 shows the ultrasonic welding machine 100. The ultrasonic welding machine 100 includes a pressure unit 101, a transmitter 102, and a vibrator 103. The pressure unit 101 presses the vibrator 103 in a direction indicated by an arrow in FIG. The ultrasonic vibration generated by the vibrator 103 is applied to the lid 38 fitted in the lid fitting recess 41 (see FIG. 5) of the case body 35 via the resonator 104 called a horn, and the fitting is performed. The annular edge 44 of the end face of the joint protrusion 43 and the edge contact portion of the tapered surface 42 are welded. Reference numeral 105 denotes a jig that supports the case body 35.

  As shown in FIG. 2, the other end of the base plate 36 in the case main body 35 projects to the side of the caliper housing 12, the electric motor 31 is attached to the other end of the base plate 36, and the output shaft 32 is attached to the gear case 34. Facing inside.

  As shown in FIGS. 2 and 3, the gear reduction mechanism 45 includes an input gear 46 attached to the output shaft 32 of the electric motor 31, a first idle gear 47 meshing with the input gear 46, and a first idle gear thereof. It has a second idle gear 48 which is provided coaxially with the gear 47 and rotates integrally with the gear 47, and an output gear 49 which meshes with the second idle gear 48, and the rotation axes of the respective gears are arranged in parallel. Parallel shaft type gear reduction mechanism.

  As shown in FIG. 5, the first idle gear 47 and the second idle gear 48 are rotatably supported by a gear shaft 50, both ends of which are supported by the base plate 36 and the lid 38 of the case body 35, via bearings 93. Has been done.

  The output gear 49 has a pair of boss portions 51 and 52 projecting to both sides on its axis, and a small diameter shaft portion 51a is provided at an end of one boss portion 51 projecting toward the base plate 36. The output gear 49 is rotatably supported by the rolling bearing 53 fitted to the small-diameter shaft portion 51a and the rolling bearing 54 fitted to the other boss portion 52.

  Here, the inner race ring 53a of the rolling bearing 53 fitted to the small diameter shaft portion 51a has a shoulder portion 55 provided at the base of the small diameter shaft portion 51a and a stopper attached to the shaft end portion of the small diameter shaft portion 51a. It is axially positioned by a wheel 56. Further, the outer race ring 53 b of the rolling bearing 53 is incorporated in a boss insertion hole 57 provided in the base plate 36 of the case body 35.

  The boss insertion hole 57 is a through hole having a large diameter hole 57a on the side facing the output gear 49, and the large diameter hole 57a serves as a bearing fitting portion. The outer race ring 53b of the rolling bearing 53 is fitted, and the outer race ring 53b is retained by the bottom of the bearing fitting portion 57a so as to be retained.

  On the other hand, the inner race ring 54a of the rolling bearing 54 fitted to the boss portion 52 is attached to the step portion 58 formed at the base of the boss portion 52 and the end portion of the boss portion 52, as shown in FIG. The retaining ring 59 is positioned axially. Further, the outer race ring 54 b of the rolling bearing 54 is incorporated in a tubular portion 60 provided on the inner side surface of the lid body 38.

  The cylindrical portion 60 is provided with a stepped hole 61 having a large diameter hole portion 61a on the side facing the output gear 49, and the large diameter hole portion 61a serves as a bearing fitting portion. The outer race ring 54b of the rolling bearing 54 is fitted. The bottom of the bearing fitting portion 61a is a pressing step 62. The pressing step portion 62 axially presses the outer race ring 54b when the lid body 38 is ultrasonically welded to the case main body 35 and welds the lid body 38 to the pair of rolling members that rotatably support the output gear 49. Preload is applied to the bearings 53 and 54.

  As shown in FIG. 2, the inner side end of the rotary shaft 26 faces the inside of the gear case 34, and the output gear 49 is serration-fitted to the inner side end thereof to prevent rotation.

  As shown in FIG. 1, between the rotary shaft 26 and the outer ring member 21, a motion conversion mechanism 70 for converting a rotary motion from the output gear 49 to the rotary shaft 26 into a linear motion in the axial direction of the outer ring member 21. It is provided.

  As shown in FIGS. 2 and 4, in the motion converting mechanism 70, a spiral ridge 72 provided on the inner circumference of the outer ring member 21 is provided on the outer circumference of a planetary roller 71 incorporated between the outer ring member 21 and the rotary shaft 26. A plurality of circumferential grooves 73 meshing with the spiral protrusion 72 are formed at equal intervals in the axial direction, and the rotation of the rotary shaft 26 causes the planetary roller 71 to rotate by frictional contact with the rotary shaft 26. While revolving, the outer ring member 21 is moved in the axial direction. Instead of the circumferential groove 73, a spiral groove having the same pitch as the spiral protrusion 72 but having different lead angles may be provided.

  Here, the planetary roller 71 is rotatably supported by a carrier 74 which is rotatably supported around the rotation shaft 26. The carrier 74 has a pair of discs 74a and 74b opposed to each other in the axial direction, and a plurality of gap adjusting members 74c are provided on one side outer peripheral portion of one disc 74a toward the other disc 74b at intervals in the circumferential direction. The pair of disks 74a and 74b are connected to each other by tightening a screw 75 screwed into the end surface of the space adjusting member 74c.

  As shown in FIG. 2, each of the pair of disks 74a and 74b is rotatably supported by a slide bearing 76 incorporated between the pair of disks 74a and 74b, and a slide bearing that rotatably supports the outer disk 74a. The bearing 76 is retained by a washer 77 fitted to the shaft end of the rotary shaft 26 and a retaining ring 78 attached to the shaft end of the rotary shaft 26.

  Further, each of the pair of disks 74a and 74b is provided with a shaft insertion hole 79 formed of a pair of elongated holes facing each other in the axial direction at intervals in the circumferential direction, and the pair of opposed shaft insertion holes 79 are provided at both ends. A planetary roller 71 is rotatably supported by each of a plurality of roller shafts 80 slidably supported by.

  Both ends of the plurality of roller shafts 80 penetrate the discs 74a, 74b, and ring grooves 80a are formed on the outer periphery of the ends of the outer faces of the discs 74a, 74b. The elastic ring 81 is assembled so as to be circumscribed. The elastic ring 81 is assembled in a state where its diameter is expanded, and its restoring elasticity urges each of the plurality of roller shafts 80 inward in the radial direction to press the planetary roller 71 against the outer diameter surface of the rotating shaft 26. There is.

  A thrust bearing 82, a pressurizing seat plate 83, and a pressure receiving seat plate 84 are sequentially installed from the planetary roller 71 side between the inner side disk 74b of the carrier 74 and the axially facing portion of the planetary roller 71, and the thrust seating plate 83 and The pressure receiving seat plate 84 is in contact with the spherical seat 85. Further, a gap is provided between the fitting surfaces of the pressure receiving seat plate 84 and the roller shaft 80, and the roller shaft 80 and the pressure seat plate 83 are freely aligned within the range of the gap.

  Further, a backup plate 86 and a thrust bearing 87 are incorporated between the inner side disk 74b of the carrier 74 and the shaft support member 23 that rotatably supports the rotary shaft 26, and the outer ring member 21 and the planetary roller 71 are interposed therebetween. The thrust bearing 87 supports the axial reaction force applied to the carrier 74.

  As shown in FIG. 1, the outer side opening of the caliper housing 12 is closed by a bellows 88 which is incorporated between the outer ring member 21 and the outer side end.

  A rotation stop groove 89 is formed on the front end surface of the cap 22 that closes the outer side end opening of the outer ring member 21, and the rotation stop groove 89 is provided with a rotation stop groove 89 provided on the pad holder 90 of the inner brake pad 15. The stop projection 91 is engaged, and the engagement prevents the outer ring member 21 from rotating with respect to the inner brake pad 15.

  Here, since the pad holder 90 is supported by the mount 16 so as to be movable in the axial direction and is prevented from rotating, the outer ring member 21 is prevented from rotating with respect to the caliper housing 12 and is movable in the axial direction. It is regarded as supportive.

  The electric brake device shown in the embodiment has the above-mentioned configuration, and FIG. 1 shows a released state of the braking force applied to the brake disc 10, and the pair of brake pads 14 and 15 are separated from the brake disc 10.

  When the electric motor 31 shown in FIG. 2 is driven in the state where the braking force is released as described above, the rotation of the output shaft 32 of the electric motor 31 is reduced by the gear reduction mechanism 45, and the rotation shown in FIGS. The rotation shaft 26 is transmitted to the shaft 26 and rotates in the braking direction.

  Since the outer diameter surface of each of the plurality of planetary rollers 71 elastically contacts the outer diameter surface of the rotation shaft 26, the rotation of the rotation shaft 26 causes the planetary roller 71 to rotate by contact friction with the rotation shaft 26. Revolve around.

  At this time, since the circumferential groove 73 formed on the outer diameter surface of the planetary roller 71 meshes with the spiral ridge 72 provided on the inner diameter surface of the outer ring member 21, the circumferential groove 73 and the spiral ridge 72 are engaged. The outer ring member 21 moves in the axial direction due to the engagement of, and the inner brake pad 15 abutted on the outer ring member 21 abuts on the brake disc 10 and starts to press the brake disc 10 in the axial direction. The reaction force of the pressing force causes the caliper 11 to move in a direction in which the outer brake pad 14 supported by the claw portion 13 approaches the brake disc 10, and the outer brake pad 14 contacts the brake disc 10, The outer brake pad 14 and the inner brake pad 15 strongly clamp the outer peripheral portion of the brake disc 10 from both sides in the axial direction, and a braking force is applied to the brake disc 10.

  When the above braking force is applied, an axial load is applied from the outer ring member 21 to the planet roller 71. The input portion of the axial load is the engaging portion of the spiral projection 72 provided on the inner diameter surface of the outer ring member 21 and the circumferential groove 73 formed on the outer diameter surface of the planet roller 71, and therefore the planet roller 71 An unbalanced load will be applied to.

  At this time, the pressure seat plate 83 and the pressure seat plate 84 are incorporated between the planet roller 71 and the inner disk 74b of the carrier 74, and the spherical seat 85 is provided on the facing surface of the both seat plates 73 and 74. As described above, when an eccentric load is applied to the planetary roller 71, the pressure seat plate 83 tilts in a state of being guided by the spherical seat 85, and the contact portion of the pressure seat plate 83 and the pressure receiving seat plate 84 moves around. The surface pressure distribution in the direction can be made uniform.

  Therefore, the axial load of the same magnitude is applied to the thrust bearing 82 over the entire circumferential direction, and there is no inconvenience of uneven wear of the raceway surface and the rolling elements.

  When the output shaft 32 of the electric motor 31 shown in FIG. 2 is rotated in the reverse direction after the braking of the brake disc 10, the rotation shaft 26 shown in FIG. The outer ring member 21 moves backward due to the engagement of the circumferential groove 73 and the spiral protrusion 72, and the outer side brake pad 14 and the inner side brake pad 15 release the clamping of the brake disc 10 and release the braking force.

  In the embodiment, as shown in FIGS. 5 and 7, the bearing fitting portion 61a provided on the lid 38 is pressed by the outer race ring 54b of the rolling bearing 54 with the lid 38 welded. Since the step portion 62 is provided, a preload is applied to the rolling bearings 53 and 54 by ultrasonically welding the lid 38 to the case body 35 in a state where the rolling bearing 54 that rotatably supports the output gear 49 is incorporated. You can

  Therefore, the output gear 49 rotates smoothly without whirling and does not generate vibration or noise.

  Further, since preload can be applied to the rolling bearings 53 and 54 without assembling preload applying parts such as elastic members and screw members, the cost can be reduced and the gear reduction device 33 can be assembled. Since it is possible to achieve simplification and it is not necessary to secure a space for incorporating the preload applying component, it is possible to obtain a small gear reduction device 33.

  In FIG. 5, when the lid body 38 is ultrasonically welded to the case body 35, the outer bearing ring 54b of the rolling bearing 54 is fixed by the pressing step portion 62 at the bottom of the bearing fitting portion 61a provided on the lid body 38. Although the bearing device of the output gear 49 that presses in the axial direction to apply the preload to each of the rolling bearings 53 and 54 is shown, the bearing device is not limited to this.

  FIG. 8 shows another example of the bearing device for the output gear 49. In this example, a pair of cylindrical boss portions 63 and 64 that project laterally are provided on both side surfaces of the output gear 49, and large-diameter hole portions 63a and 64a are formed at the open end portions of the boss portions 63 and 64. Then, the rolling bearings 53, 54 are fitted into the large diameter holes 63a, 64a, and the outer races 53b, 54b of the rolling bearings 53, 54 are connected to the bottoms and the opening ends of the large diameter holes 63a, 64a. A retaining ring 65 attached to the inner circumference is positioned in the axial direction.

  Further, stepped shaft portions 66 and 67 are provided on the base plate 36 and the lid body 38 of the case body 35, respectively, and the small diameter shaft portions 66a and 67a at the tips of the stepped shaft portions 66 and 67 are used as bearing fitting portions. The inner bearing rings 53a are fitted to the bearing fitting portions 66a, 67a by the inner bearing rings 53a, 54a of the rolling bearings 53, 54 and the step portions 68, 69 provided at the bases of the small diameter shaft portions 66a, 67a. , 54a are supported, and the stepped portion 69 of the small-diameter shaft portion (bearing fitting portion) 67a on the lid 38 side is used as a pressing stepped portion, and the pressing stepped portion 69 is used to internally cover the lid 38 during ultrasonic welding. The bearing ring 54a is pressed in the axial direction to apply a preload to each of the rolling bearings 53 and 54.

  Also in the bearing device shown in FIG. 8, the preload can be applied to the rolling bearings 53 and 54 without the need to incorporate preload applying parts such as elastic members and screw members.

10 Brake Disc 15 Brake Pad 20 Linear Actuator 31 Electric Motor 32 Output Shaft 33 Gear Reduction Device 34 Gear Case 35 Case Body 36 Base Plate 37 Peripheral Wall 38 Lid 41 Lid Fitting Recess 42 Tapered Surface 44 Annular Edge 45 Gear Reduction Mechanism 49 Output gear (gear)
53 rolling bearing 53a inner race ring 53b outer race ring 54 rolling bearing 54a inner race ring 54b outer race ring 57a large diameter hole portion (bearing fitting portion)
61a Large diameter hole (bearing fitting part)
62 Pressing Step 66 Stepped Shaft 66a Small Diameter Shaft (Bearing Fitting)
67 Stepped Shaft 67a Small Diameter Shaft (Bearing Fitting)
69 step (press step)

Claims (6)

An electric motor, a gear speed reducer that decelerates and outputs the rotation of the output shaft of the electric motor, and the rotary motion of the rotary member that is rotated by the output rotation from the gear speed reducer is converted into the linear motion of the linear motion member. In the electric linear actuator, wherein the gear reduction device includes a gear conversion mechanism having a parallel shaft type gear reduction mechanism incorporated in the gear case,
The gear case includes a case body having a peripheral wall provided on the outer peripheral portion of one surface of the base plate, and a lid body welded to an opening end portion of the peripheral wall of the case body. The base plate and the lid body each have a gear. A bearing fitting part is provided at a position facing the gear of the reduction mechanism, and a rolling bearing that rotatably supports the gear is incorporated in the bearing fitting part. A pressing step portion that presses an end surface of one of the inner and outer races of the rolling bearing on the lid side is provided , and the gear has an end surface of the other race of the inner and outer races of the rolling bearing on the gear side. An electric direct-acting actuator, characterized in that a step portion for supporting the is provided .   A stepped hole is provided in each of the base plate and the lid, the large diameter hole portion of the stepped hole serves as a bearing fitting portion, and the bottom portion of the large diameter hole portion of the lid side stepped hole serves as a pressing step portion. The electric linear motion actuator according to claim 1.   A stepped shaft portion is provided on each of the base plate and the lid, and the small diameter shaft portion of the stepped shaft portion is used as a bearing fitting portion, and the step portion of the root of the small diameter shaft portion of the lid body side stepped shaft portion is pressed. The electric linear actuator according to claim 1, which is a stepped portion.   4. The electric linear actuator according to claim 1, wherein the case body and the lid are made of resin.   A lid fitting recess is provided on the inner periphery of the opening end of the peripheral wall of the case body, a tapered surface is formed at the bottom of the lid fitting recess, and the outer periphery of the lid is in contact with the tapered surface. The electric linear actuator according to any one of claims 1 to 4, wherein an annular edge is provided and the tapered edge is welded to the annular edge. In an electric brake device that linearly drives a brake pad by an electric linear actuator, presses a brake disc with the brake pad, and applies a braking force to the brake disc,
The electric linear actuator comprises the electric linear actuator according to any one of claims 1 to 5, and a linear member of the electric linear actuator linearly drives the brake pad. An electric brake device.

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