JP2007247684A - Reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reduction gear that includes an eccentric rotor having the outer periphery being eccentric to an axial line of a motor shaft provided in an electric motor and rotating together with the motor shaft, an external tooth gear having the same axial line as that of the eccentric rotor and supported rotatably and pivotally at the outer periphery of the eccentric rotor, an internal tooth gear fixed and arranged coaxially with the motor shaft by meshing with the external tooth gear, an output member arranged coaxially with the motor shaft, and an Oldham's mechanism provided between the external tooth gear and the output member to transmit only rotation component of the external tooth gear, thereby suppressing run-out of axis due to eccentricity of the eccentric rotor and the external tooth gear securely and suppressing load applied to a bearing to small extent. <P>SOLUTION: The eccentric rotor 56 is constituted in such a way that balance of weight of the eccentric rotors 56 on both sides of an axial line C1 of the motor shaft 55 becomes substantially equal along the peripheral direction. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention provides an eccentric rotating body that has an outer periphery that is eccentric from the axis of the motor shaft included in the electric motor, and that rotates together with the motor shaft, and an outer periphery of the eccentric rotating body that has the same axis as the eccentric rotating body. An external gear that is rotatably supported and has external teeth on the outer periphery, and a motor gear shaft that is provided on the inner periphery so that a larger number of internal teeth mesh with the external teeth. An internal gear fixedly arranged coaxially, an output member arranged coaxially with the motor shaft, and provided between the external gear and the output member so as to transmit only the rotation component of the external gear. The present invention relates to a reduction gear including an Oldham mechanism.

Such a reduction gear is already known from Patent Document 1, for example.
Japanese Patent Laid-Open No. 10-51999

  However, in the one disclosed in Patent Document 1, a balancer weight is provided in the speed reducer for suppressing shaft runout caused by the eccentric rotating body and the external gear being eccentric from the axis of the motor shaft. Since the balancer weight is disposed at a position shifted in the axial direction from the eccentric rotating body, the shaft runout cannot be reliably suppressed, and a large load is generated on the bearing.

  The present invention has been made in view of such circumstances, and provides a speed reducer that can reliably suppress shaft runout due to eccentricity of an eccentric rotating body and an external gear, and can suppress a load applied to a bearing. For the purpose.

  In order to achieve the above object, the invention according to claim 1 is the same as the eccentric rotating body, the eccentric rotating body having an outer periphery eccentric with respect to the axis of the motor shaft included in the electric motor and rotating together with the motor shaft. An external gear that has an axis and is rotatably supported on the outer periphery of the eccentric rotating body and has external teeth on the outer periphery, and a larger number of internal teeth than the external teeth mesh the external teeth. The internal gear is provided on the inner periphery and fixedly arranged coaxially with the motor shaft, the output member is arranged coaxially with the motor shaft, and only the rotation component of the external gear is transmitted. In a speed reducer comprising the external gear and an Oldham mechanism provided between the output members, the weight balance of the eccentric rotating body on both sides of the axis of the motor shaft is substantially uniform along the circumferential direction. Eccentric rotating body Characterized in that it is configured.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the eccentric rotating body includes an axis of the motor shaft on a straight line connecting the axis of the motor shaft and the center of the eccentric rotating body. The balancer weight located on the opposite side to the eccentric side of the eccentric rotating body is provided so as to be accommodated in the eccentric rotating body in the axial direction and the radial direction of the eccentric rotating body.

  According to the first aspect of the invention, since the eccentric rotating body does not have a load eccentric with respect to the axis of the motor shaft, the inertial force generated by the eccentric motion can be suppressed, and a large load acts on the bearing. This prevents the shaft runout from being prevented.

  According to the second aspect of the present invention, the balancer weight can be arranged without changing the size of the speed reducer.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 8 show an embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a vehicle disc brake, FIG. 2 is a view taken along arrow 2 in FIG. 1, and FIG. 3 is shown by arrow 3 in FIG. 4 is an enlarged cross-sectional view taken along line 4-4 of FIG. 1, FIG. 5 is an enlarged view of a part indicated by an arrow 5 in FIG. 1, FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 7 is a sectional view taken along line 7-7, and FIG. 8 is a sectional view taken along line 8-8 in FIG.

  First, in FIG. 1 and FIG. 2, this vehicle disc brake can obtain a service brake state by hydraulic pressure and can be operated by the electric motor 11 to obtain a service brake state and a parking brake state. A pair of frictions disposed between the disk rotor 12 and the caliper body 13 so as to be opposed to both side surfaces of the disk rotor 12, the caliper body 13, and the disk rotor 12 rotating together with a wheel of a wheel (not shown). Pads 14 and 15 are provided.

  The caliper body 13 includes a working portion 13a supported by a bracket 16 attached to the vehicle body so as to be slidable in a direction along the axis of the disc rotor 12, and a reaction that sandwiches the disc rotor 12 between the working portion 13a. The portion 13 b is integrally connected by a bridge portion 13 c that straddles the disk rotor 12.

  The friction pad 14 facing one side of the disk rotor 12 on the side of the action part 13a is provided with a lining 17 that can slide and come into contact with the disk rotor 12 to exert a frictional force, and the disk 18 on the side of the reaction part 13b. The friction pad 15 facing the other side of the rotor 12 is formed by providing a lining 19 on the back metal 20 that can slide and contact the disk rotor 12 to exert a frictional force. As clearly shown in FIG. 2, the back metal 18 of the friction pad 14 is provided with ears 18 a, 18 a protruding from both ends along the circumferential direction of the disk rotor 12, and these ears 18 a. The holding grooves 16a and 16a provided are fitted so as to be able to move in the direction along the axis of the disk rotor 12. That is, the friction pad 14 can be moved in the direction along the axis of the disk rotor 12 and is held by the bracket 16. The friction pad 15 is also held by the bracket 16 with the same holding structure as the friction pad 14. It is possible to move in the direction along the axis of the disk rotor 12.

  A cylinder hole 21, which has an axis parallel to the axis of the disk rotor 12 and opens to the disk rotor 12 side and is closed by an end wall 22 on the side opposite to the disk rotor 12, is provided in the action portion 13 a of the caliper body 13. Are provided so as to have a circular cross-sectional shape, and a through hole 23 coaxial with the cylinder hole 21 is provided in the center of the end wall 22.

  The cylinder hole 21 has a brake fluid pressure chamber 24 formed between the end wall 22 and a brake piston 25 formed in a bottomed cylindrical shape having a closed portion 25a at the front end on the disk rotor 12 side. The front end closing portion 25a is slidably accommodated in the axial direction so as to contact the back metal 18 of the friction pad 14, and the front end closing portion 25a of the brake piston 25 prevents rotation in the cylinder hole 21. In order to do so, the back metal 18 is engaged.

  An annular piston seal 26 interposed between the caliper body 13 and the brake piston 25 is mounted on the inner surface of the cylinder hole 21, and an annular dust boot 27 is provided between the opening end of the cylinder hole 21 and the brake piston 25. And a hydraulic pressure path 28 for guiding the hydraulic pressure to the brake hydraulic pressure chamber 24 is provided in the action portion 13a.

  By the way, the brake piston 25 has an output of the electric motor 11 that exerts power for moving the friction pads 14 and 15 forward and backward with respect to the disk rotor 12, a speed reducer 32 that decelerates the output, and a rotation of the speed reducer 32. The output is transmitted via a screw mechanism 33 that is a motion conversion mechanism that converts the axial movement of the brake piston 25 into a forward / backward movement force, and the screw mechanism 33 is disposed behind the brake piston 25. The electric motor 11 is accommodated in the action part 13a of the caliper body 13 on the side opposite to the disk rotor 12, and the speed reducer 32 is attached to a speed reducer case 34 attached to the action part 13a. Be contained.

  Referring also to FIG. 3, the screw mechanism 33 includes a screw shaft 35 that is coaxial with the cylinder hole 21, and a nut 36 that is engaged with the brake piston 25 and is screwed into the screw shaft 35 while being relatively unable to rotate. The through-hole 23 of the end wall 22 is rotatable so as to transmit the rotational power of the electric motor 11 decelerated by the speed reducer 32 to the rear end of the screw shaft 35 on the side opposite to the brake piston 25. The transmission rotation shaft 37 that penetrates is coaxially and integrally connected, and the transmission rotation shaft 37 is integrally provided with a flange portion 37a that projects outward in the radial direction so as to face the end wall 22. Thus, an O-ring 38 is interposed between the end wall 22 of the operating portion 13 a and the transmission rotating shaft 37, and a thrust bearing 39 is interposed between the flange portion 37 a and the end wall 22. A retaining ring 40 that contacts the end wall 22 is mounted on the outer periphery of the protruding portion from the action portion 13a.

  Referring also to FIG. 4, the screw shaft 35 is screwed into a nut 36 surrounding the screw shaft 35 in the brake piston 25. Further, the nut 36 has an engaging portion 36a having an outer periphery of a regular square at the front end, and the front end surface of the engaging portion 36a abuts on the front end of the brake piston 25, that is, the inner surface of the closing portion 25a.

  On the other hand, on the inner periphery of the brake piston 25 having a bottomed cylindrical shape, there are locking grooves 42 that are integral multiples (twice in this embodiment) of the number of the four corners 41 of the engaging portion 36a. The corner portions 41 are selectively engaged at a plurality of locations whose phases are shifted in the circumferential direction, and are provided at equal intervals in the circumferential direction while extending in the axial direction. That is, the inner periphery of the brake piston 25 is formed in a shape corresponding to the outer periphery shape of the engaging portion 36a and a plurality of regular polygons whose phases are shifted from each other. In this embodiment, the phase is 45. It is formed in a star shape with two regular squares that are offset.

  Accordingly, the engaging groove 42 on the inner periphery of the brake piston 25, which cannot be rotated, has a simple structure in which each corner 41 of the engaging portion 36a provided on the nut 36 is engaged with the outer periphery as a regular polygon. The nut 36 can be made non-rotatable. In addition, the engaging grooves 36a are provided with locking grooves 42, which are an integral multiple of the number of corners 41, of the engaging portion 36a, on the inner periphery of the brake piston 25, and when the engaging portion 36a is engaged with the brake piston 25. Can be easily aligned, and the assemblability can be improved. Further, the air release performance is enhanced by the locking grooves 42 in which the engaging portions 36a are not locked.

  In such a screw mechanism 33, when the power from the electric motor 11 is decelerated by the speed reducer 32 and the power rotating in one direction is transmitted to the screw shaft 35 via the transmission rotating shaft 37, the brake piston 25 and The disc rotor 12 is clamped from both sides by the friction pads 14 and 15 due to the action and the reaction caused by the brake piston 25 sliding forward in the axial direction in a state in which the rotation of the nut 36 is prevented, thereby obtaining a braking force. become. Further, when the screw shaft 35 is rotated in the other direction, the brake piston 25 slides rearward in the axial direction to release the braking state.

  By the way, the screw mechanism 33 is accommodated in the brake piston 25 having a bottomed cylindrical shape, but is a rubber elastic boot 45 which is a separating means from the brake hydraulic pressure chamber 24 facing the back surface of the brake piston 25. A lubricating liquid chamber 46 isolated by the above is formed in the brake piston 25 so as to surround the screw mechanism 33, and the lubricating liquid chamber 46 is filled with a lubricating liquid such as grease or lubricating oil different from the brake liquid.

  A space 43 for allowing the screw shaft 35 to protrude forward from the nut 36 is formed between the screw mechanism 33 and the closing portion 25 a of the brake piston 25. Is connected to the lubricating fluid chamber 46 by at least one of the contact surface of the nut 36 to the closing portion 25a of the brake piston 25 and the inner surface of the closing portion 25a, in this embodiment the closing portion 25a. It is provided on the contact surface of the nut 36. As a result, the space 43 is also filled with the lubricating liquid, and the space 43 also functions as a part of the lubricating liquid chamber 46.

  One end of the elastic boot 45 is mounted on the outer periphery of the transmission rotating shaft 37 in a liquid-tight and relatively rotatable manner, and the other end of the elastic boot 45 is mounted on the inner periphery of the brake piston 25. In addition, a sliding portion 47 that is slidably contacted with the outer periphery of the transmission rotating shaft 37 in a fluid-tight manner and relative to the outer periphery of the transmission boot shaft 37 is provided on the inner periphery of the elastic boot 45. A sliding material is coated on the inner periphery of one end. Further, at one end portion of the elastic boot 45, a deformation preventing portion 48 formed by mounting a metal ring-shaped collar is provided so as to prevent elastic deformation of the elastic boot 45.

  The closing portion 25a of the brake piston 25 is provided with a through hole 50 that is closed by a detachable plug member 49, and the plug member 49 is screwed into, for example, the outer end of the through hole 50. It is attached to the blocking part 25a.

  In FIG. 1 again, the speed reducer case 34 includes a case member 51 that abuts the end portion of the caliper body 13 opposite to the disk rotor 12 of the action portion 13a and the case member 51 between the action portion 13a. The case member 51 is fastened to the action portion 13a by a plurality of bolts 53 (see FIGS. 6 and 7). The motor case 52 is fastened to the case member 51. In this fastened state, the motor shaft 55 provided in the electric motor 11 is arranged coaxially with the rotation axis of the screw mechanism 33, that is, the axis of the transmission rotation shaft 37. The An annular seal member 66 that coaxially surrounds the through hole 23 provided in the action portion 13a of the caliper body 13 is attached to the case member 51 so as to elastically contact the action portion 13a.

  The speed reducer case 34 forms a speed reducer chamber 54 that is isolated from the brake fluid pressure chamber 24 in the action portion 13 a of the caliper body 13 by the end wall 22. A reduction gear 32 is accommodated.

  Referring also to FIGS. 5 to 7, the speed reducer 32 has an eccentric rotating body 56 that has an outer periphery that is eccentric from the axis of the motor shaft 55 of the electric motor 11, and rotates together with the motor shaft 55. An external gear 57 having the same axis as the rotary body 56 and rotatably supported on the outer periphery of the eccentric rotary body 56, an internal gear 58, and the motor shaft 55 are arranged coaxially with the screw mechanism. 33, an output member 59 coupled to the transmission gear 33 through the transmission rotation shaft 37, and an Oldham mechanism 60 provided between the external gear 57 and the output member 59 so as to transmit only the rotation component of the external gear 57. Is provided.

  With further reference to FIG. 8, the eccentric rotating body 56 includes a disc portion 56 a into which the motor shaft 55 is fitted and inserted, and an electric motor 11 connected to the outer periphery of the disc portion 56 a at a right angle and integrally. It consists of the cylindrical part 56b extended to the side. On the other hand, the outer surface shape of the protruding end portion of the motor shaft 55 to the speed reducer chamber 54 is formed in a non-circular shape, and this protruding end portion is fitted and inserted into the disk portion 56a of the eccentric rotating body 56, Thereby, the eccentric rotator 56 rotates together with the motor shaft 55. Moreover, the motor shaft 55 is fitted and inserted into the disk portion 56a so as not to rotate relative to the disk portion 56a so that the center C2 of the disk portion 56a is located at a position shifted from the axis C1 of the motor shaft 55 by the eccentric amount ε. The outer periphery of the eccentric rotating body 56, that is, the outer periphery of the cylindrical portion 56 b is eccentric from the motor shaft 55 by the eccentric amount ε.

  Further, the weight balance of the eccentric rotator 56 with respect to the axis C1 of the motor shaft 55 is set so that the inertial force is not generated by the eccentric rotator 56 moving eccentrically around its rotation axis, that is, the axis C1 of the motor shaft 55. The eccentric rotator 56 is configured to be substantially uniform along the circumferential direction. In this embodiment, the eccentric rotator 56 is arranged on a straight line L connecting the axis C1 of the motor shaft 55 and the center C2 of the eccentric rotator 56. A balancer weight 67 is integrally provided on the eccentric rotator 56 on the side opposite to the eccentric side of the eccentric rotator 56 from the axis C1 of the motor shaft 55.

  Thus, the balancer weight 67 is integrally provided on the inner periphery of the cylindrical portion 56 a of the eccentric rotator 56 and is accommodated in the eccentric rotator 56 in the axial direction and the radial direction of the eccentric rotator 56. Thus, it is provided integrally with the eccentric rotator 56. Moreover, the thickness of the balancer weight 67 along the radial direction of the eccentric rotator 56 is greatest on the straight line L connecting the axis C1 of the motor shaft 55 and the center C2 of the eccentric rotator 56, and becomes thinner as it goes to both sides in the circumferential direction. Is set as follows.

  The external gear 57 is pivotally supported on the eccentric rotator 56 via a ball bearing 61 between the outer periphery of the eccentric rotator 56, and a plurality of external teeth 62, 62 are provided on the outer periphery of the external gear 57. ... are provided. Further, a larger number of internal teeth 63, 63... Than the number of the external teeth 62, 62... Are provided on the inner periphery of the internal gear 58 so as to mesh the external teeth 62, 62. The number of inner teeth 63, 63... Is set, for example, by one more than the number of outer teeth 62, 62.

  The output member 59 includes a disc portion 59a facing the external gear 57 on the side opposite to the electric motor 11, and the electric motor 11 connected to the inner periphery of the disc portion 59a at a right angle and integrally. The connecting cylindrical part 59b extending to the opposite side and the flange part 59c projecting radially inward from the end of the connecting cylindrical part 59b opposite to the electric motor 11 are integrally formed. A ball bearing 64 is interposed between 59b and the motor shaft 55, and a ball bearing 65 is interposed between the case member 51 and the connecting cylindrical portion 59b in the speed reducer case 34.

  By the way, the outer surface shape of the end portion of the transmission rotating shaft 37 that enters the speed reducer chamber 54 is non-circular, and the end portion of the transmission rotating shaft 37 is formed on the inner periphery of the flange portion 59c of the output member 59. The output member 59 is connected to the transmission rotation shaft 37 so as not to be relatively rotatable.

  Further, the Oldham mechanism 60 has a plurality of, for example, four pieces, which are fitted and fixed to the external gear 57 at equal intervals in the circumferential direction on the first virtual circle SC1 with the axis of the external gear 57 as the center. Pins 68 are provided on the disk portion 59a of the output member 59 at equal intervals in the circumferential direction on the second virtual circle SC2 with the axis of the motor shaft 55 as the center. A plurality of, for example, four connecting holes 69, which are formed to have a diameter larger than the diameter, are respectively inserted through eccentric positions.

  By the way, the internal gear 58 is sandwiched between the case member 51 and the motor case 52 in the reduction gear case 34 and is rotatably supported. The internal gear 58 functions as a worm wheel. A cylindrical worm 71 meshing with a plurality of teeth 70 provided on the outer periphery of the gear 58 is rotatably supported by the case member 51 in the reduction gear case 34, and a jig for rotating the cylindrical worm 71, such as a driver, is engaged. The cylindrical worm 71 is provided with an engaging portion 72 that enables this.

  The cylindrical worm 71 is inserted into and fitted into a cylindrical body 74 in which screw-like teeth 73 that mesh with the outer peripheral teeth 70 of the internal gear 58 are engraved on the outer periphery, and the cylindrical body 74 is relatively unrotatable. And a support shaft 75. The case member 51 of the speed reducer case 34 is provided with a worm support hole 76 that rotatably accommodates the cylindrical worm 71. The worm support hole 76 accommodates the cylindrical body 74 and a side surface thereof. A housing hole portion 76a that opens a part of the housing gear 51 into the case member 51 and faces a portion of the outer teeth 70 of the internal gear 58, and a first bottomed portion that is coaxially connected to one end of the housing hole portion 76a. The second support hole 76b includes a support hole 76b and a second support hole 76c having an outer end opened to the outside of the case member 51 and an inner end connected coaxially to the other end of the accommodation hole 76a. 76c is formed larger in diameter than the first support hole 76b.

  The support shaft 75 is fitted to and supported by the first support hole portion 76b, and a fitting shaft that passes through the cylindrical body 74 coaxially and relatively non-rotatably with a non-circular cross-sectional shape. Part 75b and second support shaft part 75c fitted and supported in second support hole part 76c, and abuts and engages with the outer peripheral edge of second support shaft part 76c. A retaining ring 77 is attached to the inner periphery of the second support hole 76c. Further, the engaging portion 72 is formed as a recess opening at the outer end of the second support shaft portion 75c.

  Moreover, a plug member 78 that closes the outer end opening of the worm support hole 76, that is, the outer end opening of the second support hole 76c, is detachably attached to the case member 51 of the speed reducer case 34.

  Next, the operation of this embodiment will be described. The operating portion 13a of the caliper body 13 is provided with a cylinder hole 21 opened on the disc rotor 12 side, and a brake piston 25 is formed on the back surface in the operating portion 13a. The brake is slidably fitted into the cylinder hole 21 so as to face the brake fluid pressure chamber 24 and has a closed portion 25a at the end on the disk rotor 12 side and is formed in a bottomed cylindrical shape. A screw mechanism 33 is accommodated in the piston 25, and a lubricating fluid chamber 46 that is isolated from the brake fluid pressure chamber 24 by an elastic boot 45 is formed in the brake piston 25 so as to surround the screw mechanism 33. The lubricating liquid chamber 46 is filled with different lubricating liquids.

  Therefore, the screw mechanism 33 is lubricated by the lubricating liquid in the lubricating fluid chamber 46 that is isolated from the brake fluid pressure chamber 24 by the elastic boot 45, and the screw mechanism 33 is sufficiently lubricated. It is possible to increase the life of 33 and improve transmission efficiency.

  The screw mechanism 33 includes a screw shaft 35 to which the rotational power from the electric motor 11 is transmitted, and a nut 36 that is screwed to the screw shaft 35 and comes into contact with the closing portion 25a of the brake piston 25. A communication groove 44 for communicating a space 43 formed between the closed portions 25a of the brake piston 25 with the lubricating liquid chamber 46 is provided on at least a contact surface of the nut 36 with the closed portion 25a and an inner surface of the closed portion 25a. On the other hand, in this embodiment, the nut 36 is provided on the contact surface of the nut 36 with the closing portion 25a, so that the space 43 is made part of the lubricating liquid chamber 46 by communicating the lubricating liquid chamber 46 with the space 43. It can comprise and can lubricate the screwed part of the screw shaft 35 and the nut 36 more effectively.

  In addition, one end of the elastic boot 45 is mounted in a liquid-tight and relatively rotatable manner on the outer periphery of the transmission rotating shaft 37 that inputs the rotational power transmitted from the electric motor 11 through the speed reducer 32 to the screw mechanism 33, and is elastic. The other end of the boot 45 is attached to the inner periphery of the brake piston 25, and the brake fluid pressure chamber 24 and the lubricating fluid chamber 46 can be isolated with a simple structure using the elastic boot 45.

  Further, a sliding portion 47 is provided on the inner periphery of one end portion of the elastic boot 45 so as to be slidably contacted with the outer periphery of the transmission rotation shaft 37 in a liquid-tight and relatively rotatable manner. Since the sliding material is coated on the inner periphery of the portion, the elastic boot 45 is prevented from being twisted despite the rotation of the transmission rotating shaft 37, and between the brake fluid pressure chamber 24 and the lubricating fluid chamber 46. Can be isolated. In addition, a deformation preventing portion 48 for preventing elastic deformation of the elastic boot 45 is provided at one end of the elastic boot 45, so that the elastic boot 45 can be prevented from being elastically deformed.

  Further, since the through hole 50 closed by the removable plug member 49 is provided in the closing part 25a of the brake piston 25, the brake piston 25, the screw mechanism 33, and the elastic boot 45 are assembled to the caliper body 13 and then lubricated. The liquid chamber 46 can be filled with a lubricating liquid, and the through-hole 50 can be accessed only by removing the friction pad 14 during maintenance, so that the lubricating liquid can be easily replaced and vented. .

  The speed reducer 32 that decelerates the rotational power of the electric motor 11 has an eccentric rotator 56 that has an outer periphery that is eccentric from the axis of the motor shaft 55 of the electric motor 11 and rotates together with the motor shaft 55, and the eccentric rotation. More than the number of external gears 57 having the same axis as the body 56 and rotatably supported on the outer periphery of the eccentric rotator 56 and having a plurality of external teeth 62. A large number of internal teeth 63... Are provided on the inner periphery so as to mesh the external teeth 62. The internal gear 58 is disposed coaxially with the motor shaft 55. The internal gear 58 is disposed coaxially with the motor shaft 55. An output member 59 connected to the mechanism 33 and an Oldham mechanism 60 provided between the external gear 57 and the output member 59 so as to transmit only the rotation component of the external gear 57 are provided. Collect Thus, the internal gear 58 is rotatably supported on the speed reducer case 34 disposed in the caliper body 13 and is provided on the outer periphery of the internal gear 58 so that the internal gear 58 functions as a worm wheel. A cylindrical worm 71 that meshes with the plurality of teeth 70 is rotatably supported, and an engaging portion 72 that can engage a jig that rotates the cylindrical worm 71 is provided in the cylindrical worm 71. .

  According to such a reduction gear 32, although the force for rotating the internal gear 58 acts on the internal gear 58 from the external gear 57 in accordance with the rotation of the eccentric rotating body 56 due to the rotation operation of the electric motor 11, When the cylindrical worm 71 is not operated, the cylindrical worm 71 is not rotated by the transmission of force from the internal gear 58 to the cylindrical worm 71, and the cylindrical worm 71 and the internal gear 58 are stationary. In such a stationary state of the internal gear 58, according to the rotation of the eccentric rotator 56, it corresponds to the difference between the number of internal teeth 63 of the internal gear 58 and the number of external teeth 62 of the external gear 57. The external gear 57 rotates with the reduction ratio, and the rotation component of the external gear 57 is input to the screw mechanism 33 via the Oldham mechanism 60, and the brake piston 25 is driven in the axial direction.

  Further, by adjusting the reduction ratio by meshing of the cylindrical worm 71 and the internal gear 58, the balance of the rotational operation amount and the rotational operation force of the cylindrical worm 71 can be freely set regardless of the configuration of the speed reducer 32 or the electric motor 11 itself. It becomes possible. In addition, when the operation of the electric motor 11 becomes impossible due to power supply abnormality or seizure of the motor shaft 55 in the brake state, the cylindrical worm 71 is rotated so as to be separated from the electric motor 11 and the internal gear 58. Can be rotated, whereby the external gear 57 can be rotated to release the brake state.

  Further, a worm support hole 76 is provided in the case member 51 of the speed reducer case 34 with a part of the outer teeth 70 of the internal gear 58 facing each other and one end opened to the outside, and the engaging portion 72 is provided at one end. An entire cylindrical worm 71 provided is accommodated and supported in the worm support hole 76 with the engaging portion 72 disposed on the outer end side, and a plug member 78 that closes the outer end opening of the worm support hole 76 is provided as a reduction gear. Since it is detachably attached to the case member 51 of the case 34, the entire cylindrical worm 71 is accommodated in the speed reducer case 34 to avoid an increase in the size of the entire disc brake, and the engaging portion 72 of the cylindrical worm 71 is used. Intrusion of foreign matter into the speed reducer case 34 can be prevented while enabling external access to the speed reducer case 34.

  Further, the Oldham mechanism 60 has a plurality of pins 68 provided on the external gear 57 at equal intervals in the circumferential direction on the first virtual circle SC1 with the axis of the external gear 57 as the center. Are provided on the disk portion 59a of the output member 59 at equal intervals in the circumferential direction on the second virtual circle SC2 with the axis C1 as the center, and are formed to have a diameter larger than the diameter of each pin 68. Each of the plurality of connecting holes 69 is inserted through the eccentric position, so that the configuration of the Oldham mechanism 60 can be simplified, the assemblability can be improved, and shaft shake can be prevented from occurring.

  Further, since the eccentric rotator 56 is configured such that the weight balance of the eccentric rotator 56 on both sides of the axis C1 of the motor shaft 55 is substantially uniform along the circumferential direction, the eccentric rotator 56 is the axis of the motor shaft 55. There is no eccentric load with respect to C1, the inertial force generated by the eccentric motion can be suppressed, and a large load is prevented from acting on a bearing such as the ball bearing 64 and the shaft runout is reliably suppressed. Can do.

  Moreover, the eccentric rotator 56 is located on the opposite side of the eccentric side of the eccentric rotator 56 from the axis C1 of the motor shaft 55 on the straight line L connecting the axis C1 of the motor shaft 55 and the center C2 of the eccentric rotator 56. Since the balancer weight 67 is provided so as to be accommodated in the eccentric rotator 56 in the axial direction and the radial direction of the eccentric rotator 56, the balancer weight 67 is arranged without changing the size of the speed reducer 32. Can do.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

  For example, in the above embodiment, a case has been described in which the balancer weight 67 is provided in the eccentric rotation 56 so that the weight balance of the eccentric rotation body 56 is substantially uniform along the circumferential direction. The weight may be reduced by providing a recess in the eccentric rotating body 56 on the eccentric side of the eccentric rotating body 56 from the axis C1 of the motor shaft 55 on the straight line L connecting the centers C2 of the eccentric rotating body 56. Since the balancer weight 67 only needs to rotate integrally with the eccentric rotator 56, the balancer weight 67 made of a member different from the eccentric rotator 56 may be fixed to the eccentric rotator 56 or integrally formed.

It is a longitudinal cross-sectional view of the disk brake for vehicles. FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1. FIG. 3 is an enlarged view of a portion indicated by an arrow 3 in FIG. 1. FIG. 4 is an enlarged sectional view taken along line 4-4 of FIG. FIG. 5 is an enlarged view of a part indicated by an arrow 5 in FIG. 1. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 1. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Electric motor 32 ... Reduction gear 55 ... Motor shaft 56 ... Eccentric rotating body 57 ... External gear 58 ... Internal gear 59 ... Output member 60 ... Oldham Mechanism 62 ... External teeth 63 ... Internal teeth 67 ... Balancer weight C1 ... Motor shaft axis C2 ... Center of eccentric rotating body L ... Motor shaft axis and center of eccentric rotating body Straight line connecting

Claims (2)

  An eccentric rotator (56) having an outer periphery eccentric with respect to the axis of the motor shaft (55) provided in the electric motor (11) and rotating together with the motor shaft (55), and the same axis as the eccentric rotator (56) An external gear (57) rotatably supported on the outer periphery of the eccentric rotating body (56) and provided with outer teeth (62) on the outer periphery, and a larger number than the outer teeth (62). The internal teeth (63) are provided on the inner periphery so as to mesh with the external teeth (62) and are fixedly arranged coaxially with the motor shaft (55), and the motor shaft ( 55) provided between the external gear (57) and the output member (59) so as to transmit only the rotation component of the external gear (57) and the output member (59) arranged coaxially with the external gear (55). In the reducer comprising the Oldham mechanism (60), the front The eccentric rotating body (56) is configured such that the weight balance of the eccentric rotating body (56) on both sides of the axis (C1) of the motor shaft (55) is substantially uniform along the circumferential direction. And reducer.   The eccentric rotating body (56) has an axis of the motor shaft (55) on a straight line (L) connecting the axis (C1) of the motor shaft (55) and the center (C2) of the eccentric rotating body (56). The balancer weight (67) located on the side opposite to the eccentric side of the eccentric rotating body (56) from (C1) is disposed in the eccentric rotating body (56) in the axial direction and the radial direction of the eccentric rotating body (56). The speed reducer according to claim 1, wherein the speed reducer is provided so as to be accommodated in the motor.

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