Friction Torque Output Device

Abstract

To provide a friction torque output device capable of widening a selection range of a material and improving friction characteristics.SOLUTION: A housing 3 to which an electric motor is attached, an adjustment screw 5 that receives a rotational output from the electric motor via a speed reduction mechanism, a movable pressing body 7 that is pressed and moved in an axial direction by a pressing portion 71, a friction torque output shaft 9 that is rotatably supported by the housing, an output rotor 11 that rotates together with the friction torque output shaft 9, a torque generation portion 13 that frictionally engages between the housing 3 and the output rotor 11, and a transmission portion 15 that transmits a propulsive force generated in the adjustment screw 5 so as to be received by the housing 3, wherein the torque generation portion 13 includes a male tapered surface 87 and a female tapered surface 89 that face each other so as to be capable of being fastened to each other; Male tapered surface 87 is provided in outer circumferential portion 77, outer circumferential portion 77 is engaged with inner circumferential portion 99 of outputting rotator 11 in the rotational direction and loosely fitted thereto in the radial direction, and female tapered surface 89 is provided in the inner circumferential portion of the clutch ring side 91a, side 91b engaged with housing 3 in the rotational direction and opposed to pressing portion 71 in the axial direction.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a friction torque output device that frictionally engages a torque generating unit by means of an electric motor. [Background Art]

[0002] Conventionally, as a friction torque output device, there is an electromagnetic clutch shown in FIG. 6 described in Patent Document 1.

[0003] This electromagnetic clutch includes a housing 201, an electromagnetic mechanism 203, an armature 205, a cam mechanism 207, a receiving portion 209, a first coupling portion 211, a second coupling portion 213, and a clutch portion 215.

[0004] The electromagnetic mechanism 203 is supported by the housing 201, and the armature 205 is arranged to be relatively rotatable and attractable with respect to the electromagnetic mechanism 203.

[0005] The cam mechanism 207 exerts a cam thrust force between a pair of cam members 217 and 219 by the relative rotation of the two cam members 217 and 219, and transmits torque.

[0006] The receiving portion 209 restricts the movement of the one cam member 217 in the axial separating direction relative to the other cam member 219.

[0007] In the first coupling portion 211, the armature 205 and the one cam member 217 mesh with each other, and the second coupling portion 213 couples the other cam member 219 to a shaft 221 so that they can rotate integrally.

[0008] The clutch portion 215 is formed between the other cam member 219 and the housing 201, and receives the cam thrust force to bring the other cam member 219 into frictional engagement with the housing 201.

[0009] In such an electromagnetic clutch, for example, the housing 201 side is attached to a fixed side, and the shaft 221 is coupled to an object to be braked.

[0010] Furthermore, when the electromagnetic coil of the electromagnetic mechanism 203 is turned off, even if there is a rotational input to the shaft 221 from the object to be braked, the cam mechanism 207 and armature 205 rotate relative to the housing 201 together with the shaft 221, thus allowing the shaft 221 to rotate freely.

[0011] When the electromagnetic coil of the electromagnetic mechanism 203 is energized, the armature 205 is attracted in accordance with the electromagnetic force. This attraction causes the armature 205 to slide and rotate while experiencing rotational resistance corresponding to the magnetic force. This sliding rotation causes one cam member 217 of the cam mechanism 207 to experience rotational resistance. On the other hand, the rotation of the shaft 221 causes the other cam member 219 of the cam mechanism 207 to experience rotational force.

[0012] The rotational resistance acting on one cam member 217 on the electromagnetic mechanism 203 side and the rotational force acting on the other cam member 219 on the shaft 221 side generate a cam thrust force in the cam mechanism 207.

[0013] Due to this cam thrust force, the clutch portion 215 frictionally engages in accordance with the cam thrust force, and a braking force is applied to the shaft 221 via the cam member 219.

[0014] Furthermore, the rotational resistance of the armature 205 due to the electromagnetic mechanism 203 acts on the shaft 221 via the cam mechanism 207.

[0015] Therefore, when the electromagnetic coil is energized, the shaft 221 receives a braking force due to a braking force corresponding to the cam thrust force and a rotational resistance corresponding to the electromagnetic force, thereby braking the target.

[0016] However, this conventional structure required the use of magnetic materials for the friction components, which made it difficult to address issues such as stick-slip. [Prior art documents] [Patent Documents]

[0017] [Patent Document 1] Japanese Patent Publication No. 2021-81004 [Overview of the project] [Problems that the invention aims to solve]

[0018] The problem we are trying to solve is that electromagnetic clutches require the use of magnetic materials for the friction components, which makes it difficult to address issues such as stick-slip. [Means for solving the problem]

[0019] The friction torque output device of the present invention, in order to broaden the range of material selection and enable improved friction characteristics, comprises: a housing to which an electric motor is attached; an adjustment screw rotatably disposed within the housing and having a male threaded portion which receives rotational output from the electric motor via a reduction mechanism and is coupled to the reduction mechanism so as to be movable in the axial direction; a movable pressing body which has a female threaded portion on its inner circumference that screws into the male threaded portion and a pressing portion on its outer circumference, and the pressing portion moves axially due to the rotation of the male threaded portion; a friction torque output shaft rotatably supported in the housing; an output rotating body disposed within the housing and rotating together with the friction torque output shaft; and a housing disposed between the movable pressing body and the output rotating body which receives the pressing force from the pressing portion. The device comprises a torque generating unit that frictionally engages the jing and the output rotating body, and a transmission unit disposed between the adjustment screw and the housing that transmits the thrust force generated in the adjustment screw by the reaction force acting on the pressing unit to the housing. The torque generating unit is provided with a male tapered surface and a female tapered surface that are fastened to each other, the male tapered surface is provided on the outer circumference which is separated from the inner circumference of the output rotating body, the separated outer circumference which is disposed axially between the pressing unit and the receiving unit provided on the housing and is rotationally engaged with the inner circumference of the output rotating body and loosely fitted radially, and the female tapered surface is provided on the inner circumference of a clutch ring which is rotationally engaged with the housing and axially opposed to the pressing unit. [Effects of the Invention]

[0020] The friction torque output device of the present invention has the above-described configuration. Since the frictional engagement of the torque generating part can be controlled by the rotational output of the electric motor, a magnetic material for forming a magnetic path for causing frictional engagement is not required, the range of material selection can be widened, and friction characteristics can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] [Figure 1] FIG. 1 is a cross-sectional view of a friction torque output device according to Reference Example 1. [Figure 2] FIG. 2 is an essential part cross-sectional view showing the engagement between an adjustment screw and a speed reduction mechanism according to Reference Example 1. [Figure 3] FIG. 3 is a cross-sectional view of a friction torque output device according to Reference Example 2. [Figure 4] FIG. 5 is a cross-sectional view taken along line IV-IV in FIG. 5 according to Embodiment 1. [Figure 5] FIG. 4 is a cross-sectional view taken along line V-V in FIG. 4 according to Embodiment 1. [Figure 6] FIG. 6 is a cross-sectional view of an electromagnetic clutch according to a conventional example. MODES FOR CARRYING OUT THE INVENTION

[0022] The present invention achieves the object of widening the range of material selection and enabling improvement of friction characteristics as follows.

[0023] The device comprises a housing to which an electric motor is attached, an adjustment screw rotatably disposed within the housing and having a male threaded portion which receives rotational output from the electric motor via a reduction mechanism and is coupled to the reduction mechanism so as to be movable in the axial direction, a movable pressing body which has a female threaded portion on its inner circumference which screws onto the male threaded portion and a pressing portion on its outer circumference which presses and moves in the axial direction as the male threaded portion rotates, a friction torque output shaft rotatably supported in the housing, an output rotating body disposed within the housing and rotating together with the friction torque output shaft, a torque generating unit disposed between the movable pressing body and the output rotating body which receives the pressing force from the pressing portion and frictionally engages the housing and the output rotating body, and a transmission unit disposed between the adjustment screw and the housing which transmits the thrust force generated in the adjustment screw by the reaction force acting on the pressing portion so as to be received by the housing.

[0024] The torque generating unit can be realized using a non-magnetic material, taking into account its frictional properties.

[0025] The housing can be made from non-magnetic materials such as aluminum alloy or resin. Alternatively, the housing can be made from magnetic materials such as steel.

[0026] The electric motor and reduction mechanism are configured as an integrated geared motor, but they can also be implemented as separate components.

[0027] The movable pressing body can be realized in either a form in which the outer circumference with a pressing portion and the inner circumference with a female thread portion are formed from separate materials and joined together, or in a form in which they are formed integrally from a single material.

[0028] The movable pressing body and the output rotating body are formed in a disc shape, but it is sufficient that a torque generating unit is placed between them, and the shape can be freely determined.

[0029] The output rotating body can also be realized by having an outer circumference with a male tapered surface that is formed separately from the inner circumference.

[0030] The torque generating unit can be implemented by frictionally engaging the housing and the output rotating body, and its configuration can be freely determined.

[0031] The torque generating unit may also be implemented in a configuration in which a multi-plate clutch consisting of an inner plate and an outer plate is provided, the multi-plate clutch is arranged axially between the pressing portion and the receiving portion provided on the housing side, the inner plate engages in the rotational direction with the outer circumference of the output rotating body, and the outer plate engages in the rotational direction with the inner circumference of the housing.

[0032] The torque generating unit can also be realized in a configuration in which a male tapered surface and a female tapered surface are provided facing each other so as to be able to fasten together, the male tapered surface is provided on the outer circumference of the output rotating body, and the female tapered surface is provided on the inner circumference of a clutch ring that engages with the housing in the rotational direction and faces the pressing portion in the axial direction.

[0033] The torque generating unit can also be realized in a configuration in which a male tapered surface and a female tapered surface are provided facing each other so as to be able to fasten together, the male tapered surface is provided on an outer circumference that is separated from the inner circumference of the output rotating body, the separated outer circumference is positioned axially between the pressing portion and the receiving portion provided on the housing side and engages with the inner circumference of the output rotating body in the rotational direction and loosely fits in the radial direction, and the female tapered surface is provided on the inner circumference of a clutch ring that engages with the housing in the rotational direction and faces the pressing portion in the axial direction. [Examples]

[0034] Figure 1 is a cross-sectional view of a friction torque output device relating to Reference Example 1. Figure 2 is a cross-sectional view of the main part showing the engagement between the adjustment screw and the reduction mechanism.

[0035] As shown in Figure 1, the friction torque output device 1 comprises a housing 3, an adjustment screw 5, a movable pressing body 7, a friction torque output shaft 9, an output rotating body 11, a torque generating unit 13, and a transmission unit 15.

[0036] The housing 3 is made of an aluminum alloy or the like. The housing 3 consists of a shaft side portion 17 and a motor side portion 19.

[0037] The shaft side portion 17 has a shape in which a shaft support cylinder 23 is integrally provided on the inner circumference of the shaft side main portion 21. Between the shaft side main portion 21 and the shaft support cylinder 23, one shaft support portion 25 is formed at the end of the shaft support cylinder 23. The other shaft support portion that is paired with the shaft support portion 25 is formed on the shaft support cylinder 23 or the like, although it is not shown. The shaft side main portion 21 has a circumferential shaft side wall portion 27 that runs radially, and a stepped receiving portion 29 is provided around the outer circumference of this shaft side wall portion 27. The outer peripheral edge of the receiving portion 29 is provided with an outer peripheral wall portion 31.

[0038] The motor side portion 19 has a shape in which a motor support portion 35 is integrally provided with the motor side main portion 33. The motor side main portion 33 has a circumferential motor side wall portion 37 that runs radially, and an inner circumferential wall portion 39 is provided circumferentially on the outer circumference of this motor side wall portion 37. The inner circumferential wall portion 39 fits into the inner circumference of the outer circumferential wall portion 31, and the edge of the outer circumferential wall portion 31 abuts against the outer circumferential edge of the motor side wall portion 37.

[0039] The motor-side main body 33 is integrally connected to the shaft-side main body 21 by fastening nuts 43 to bolts 41 that penetrate the shaft-side side wall 27 and the outer circumference of the motor-side side wall 37. Multiple bolts 41 are provided at predetermined intervals in the circumferential direction. Each bolt 41 is exposed on the inner side along the inner circumferential wall 39.

[0040] The motor support portion 35 is positioned eccentrically toward the shaft center and is formed to be thicker than the motor side wall portion 37. On the inner surface of the motor support portion 35, a thrust bearing portion 45 is formed by a recess around the shaft center. The motor support portion 35 is formed through the shaft center (not shown), and the reduction output shaft 47 is positioned through it.

[0041] A geared motor 49 is positioned on the outer surface of the motor support portion 35. The geared motor 49 is fastened and fixed to the motor support portion 35 from the inner side by screws 51. The geared motor 49 integrates an electric motor 52 and a reduction mechanism 53. The reduction output shaft 47 protrudes from the reduction mechanism 53.

[0042] The adjustment screw 5 is rotatably positioned at the axial center of the housing 3. The adjustment screw 5 is cylindrical and has a male threaded portion 55 on its outer circumference. The adjustment screw 5 is coupled to the reduction output shaft 47 of the geared motor 49. This coupling allows the adjustment screw 5 to receive rotational output from the electric motor 52 via the reduction mechanism 53.

[0043] As shown in Figures 1 and 2, the adjustment screw 5 is coupled to the geared motor 49 by three equally spaced pins 57 in the circumferential direction. The adjustment screw 5 is fitted onto the reduction output shaft 47 of the geared motor 49, and the pins 57 are interposed between the inner and outer circumferences of the adjustment screw 5 and the reduction output shaft 47. The adjustment screw 5 is movable axially relative to the reduction output shaft 47 of the reduction mechanism 53.

[0044] The transmission unit 15 is positioned between the adjustment screw 5 and the housing 3. The transmission unit 15 transmits the thrust force generated in the adjustment screw 5 by the reaction force acting on the pressing part of the movable pressing body 7 (described later) to the thrust receiving part 45 of the housing 3. The transmission unit 15 includes a thrust plate 59, a wire clip 61, and a thrust needle bearing 63.

[0045] The thrust plate 59 is fixed to the base of the adjustment screw 5 by press-fitting or the like, and is positioned relative to the adjustment screw 5 by the wire clip 61. The thrust plate 59 faces the washer 64 of the thrust receiving portion 45 in the axial direction via the thrust needle bearing 63.

[0046] The movable pressing body 7 is a circumferentially shaped adjustment plate with an internal threaded portion 67 on its inner circumference 65 and a pressing portion 71 on its outer circumference 69. The movable pressing body 7 is formed by creating the outer circumference 69 with the pressing portion 71 and the inner circumference 65 with the internal threaded portion 67 from separate materials and then integrally joining them by welding, brazing, press-fitting, or the like.

[0047] The outer circumference 69 of the movable pressing body 7 is formed of, for example, carbon steel and is a stepped, donut-shaped disc plate. The inner circumference 65 of the movable pressing body 7 is formed of, for example, phosphor bronze and is in the shape of a ring. The female thread portion 67 of the inner circumference 65 is screwed onto the male thread portion 55 of the adjustment screw 5. The rotation of the male thread portion 55 causes the pressing portion 71 to move axially. The lead angle and friction angle of the male thread portion 55 of the adjustment screw 5 and the female thread portion 67 on the movable pressing body 7 side are designed to be approximately equal, so that the rotational transmission efficiency from the female thread portion 67 to the male thread portion 55 is set low. For this reason, even if the inner circumference 65 of the movable pressing body 7 moves axially toward the reduction mechanism 53, the rotation of the male thread portion 55 is restricted.

[0048] The pressing portion 71 of the movable pressing body 7 is located on the outermost circumference via a bent portion 73 and is oriented in the axial direction. The pressing portion 71 of the movable pressing body 7 is rotationally engaged with the bolt 41.

[0049] The friction torque output shaft 9 is rotatably supported by the housing 3 and is linked to the object to be braked. The friction torque output shaft 9 is supported on one side by a ball bearing 75 at the shaft support portion 25, and on the other side by a ball bearing or the like at a shaft support portion (not shown).

[0050] The output rotating body 11 is configured such that its inner circumference is integrally coupled to the friction torque output shaft 9 and it rotates together with the friction torque output shaft 9. This output rotating body 11 is an output plate with splines 79 on its outer circumference 77. The output rotating body 11 is located inside the housing 3 and is in close proximity to and facing the movable pressing body 7. The outer circumference 77 of the output rotating body 11 is positioned so that its axial end overlaps radially with the bent portion 73 of the movable pressing body 7.

[0051] The torque generating unit 13 is equipped with a multi-plate clutch 81. The multi-plate clutch 81 consists of an inner plate 83 and an outer plate 85. The multi-plate clutch 81 is positioned axially between the pressing portion 71 and the receiving portion 29 provided in the housing 3. The outer circumference 77 of the output rotating body 11 of the inner plate 83 is engaged in the spline 79 in the rotational direction. The outer plate 85 is engaged in the bolt 41 in the rotational direction on the inner circumference of the housing 3.

[0052] [braking] In the friction torque output device 1 with this configuration, for example, the housing 3 is attached to the fixed side, and the friction torque output shaft 9 is coupled to the object to be braked. However, the friction torque output device 1 can also be used as various torque transmission devices.

[0053] When the geared motor 49 is energized and controlled by the controller, the electric motor 52 causes the reduction output shaft 47 of the reduction mechanism 53 to rotate at a reduced speed. The rotation of the reduction output shaft 47 causes the male threaded portion 55 to drive the female threaded portion 67, causing the inner circumference 65 of the movable pressing body 7 to move axially toward the output rotating body 11.

[0054] The movement of the movable pressing body 7 causes the pressing part 71 to press against the multi-plate clutch 81, thereby controlling the engagement of the multi-plate clutch 81 with respect to the receiving part 29.

[0055] This fastening control causes the outer circumference 77 of the output rotating body 11 to receive rotational resistance from the bolt 41 on the housing 3 side via the multi-plate clutch 81. This rotational resistance corresponds to the fastening force of the multi-plate clutch 81.

[0056] Therefore, the rotational resistance of the output rotating body 11 is transmitted to the friction torque output shaft 9, allowing the target to be braked. In this case, by controlling the rotational speed of the geared motor 49, an axial thrust proportional to the rigidity of the member to which the axial thrust and its reaction force are transmitted can be obtained relative to the motor rotation position, enabling precise torque control.

[0057] During the aforementioned braking, if there is an axial reaction force from the object being braked to the friction torque output shaft 9, it is transmitted from the output rotating body 11 to the torque generating unit 13. This reaction force acts on the pressing portion 71 of the movable pressing body 7 with a magnitude corresponding to the fastening force of the multi-plate clutch 81. The reaction force transmitted to the pressing portion 71 is input to the threaded portion between the female threaded portion 67 and the male threaded portion 55 between the inner circumference 65 of the movable pressing body 7 and the adjustment screw 5. At this time, since there is no reverse transmission efficiency in the threaded portion, the reverse rotation of the adjustment screw 5 is restricted even if the motor output torque is set to 0.

[0058] Therefore, it is not necessary to continuously energize the geared motor 49 in order to maintain the friction torque of the object being braked, thus improving energy efficiency.

[0059] When the braking reaction force occurs, the adjustment screw 5 receives a thrust force toward the reduction mechanism 53 relative to the reduction output shaft 47. This thrust force is transmitted to the thrust receiving portion 45 via a washer 64 through the wire clip 61, thrust plate 59, and thrust needle bearing 63 by the sliding of the adjustment screw 5.

[0060] Therefore, even if a thrust force acts on the adjustment screw 5 toward the reduction mechanism 53 when the torque generating unit 13 is operating, it is absorbed by the thrust receiving portion 45 of the housing 3 and is not input to the reduction output shaft 47, thus maintaining durability.

[0061] When the multi-plate clutch 81 is not engaged and power is turned off to the geared motor 49, even if there is a rotational input to the friction torque output shaft 9 from the object being braked, the inner plate 83 of the multi-plate clutch 81 can rotate freely relative to the outer plate 85.

[0062] Since the frictional engagement of the torque generating unit 13 can be controlled by the rotational output of the geared motor 49, the range of materials that can be selected for the torque generating unit 13 and other components that perform the frictional engagement can be broadened, thereby enabling an improvement in frictional characteristics.

[0063] Specifically, it becomes unnecessary to use magnetic materials in the multi-plate clutch 81, allowing suitable materials to be used as friction members for the inner plate 83 and outer plate 85, thereby improving the friction torque characteristics.

[0064] The multi-plate clutch 81 and the housing 3 are engaged via bolts 41 that fasten the housing 3. Therefore, the housing 3 can be made of aluminum alloy or resin, allowing for weight reduction.

[0065] Figure 3 is a cross-sectional view of a friction torque output device relating to Reference Example 2. Components identical to or corresponding to those in Reference Example 1 are denoted by the same reference numerals and described accordingly; redundant explanations are omitted.

[0066] This Reference Example 2 differs from Reference Example 1 in the configuration of the torque generating unit 13.

[0067] As shown in Figure 3, the torque generating unit 13 in this Reference Example 2 is a cone clutch 86 instead of the multi-plate clutch 81 of Reference Example 1. The cone clutch 86 is provided with a male tapered surface 87 and a female tapered surface 89 facing each other so as to be able to fasten together.

[0068] The male tapered surface 87 is provided on the outer circumference 77 of the output rotating body 11.

[0069] The female tapered surface 89 is provided on the inner circumference of the clutch ring 91. The clutch ring 91 is rotationally engaged with the bolt 41 on the housing 3 side and faces the pressing portion 71 of the movable pressing body 7 in the axial direction.

[0070] In this reference example 2, the outer circumference 77 of the output rotating body 11 is formed separately from the inner circumference 92. The outer circumference 77 and the inner circumference 92 are fitted together by a spline 94. Therefore, the outer circumference 77 can move relative to the inner circumference 92 in the axial direction. Behind the outer circumference 77, a thrust washer 96 is interposed between it and the shaft-side wall 27. Therefore, the axial force that the outer circumference 77 receives when the cone clutch 86 is engaged can be received by the shaft-side wall 27 via the thrust washer 96.

[0071] In this reference example 2, the friction torque output shaft 9 of the output rotating body 11 is rotatably supported by ball bearings 75a and 75b on the shaft support portions 25a and 25b of a stepped shaft support cylinder 23. A seal support portion 25c is formed between the shaft support portions 25a and 25b of the support cylinder 23, housing an oil seal 93 such as an O-ring or X-ring, which is in close contact with the outer surface of the friction torque output shaft 9.

[0072] The outer end of the friction torque output shaft 9 is provided with a keyway 95 for a key. The key placed in the keyway 95 prevents rotation of the flange member or the like that which connects to the side to be braked. The outer end of the friction torque output shaft 9 is provided with a male threaded portion 97 for fastening a nut or the like. The flange member or the like is fastened and fixed by screwing a nut onto the male threaded portion 97. Fastening of the flange member or the like to the shaft may also be done by a spline or the like, instead of a key.

[0073] The housing 3 is configured such that the motor-side main body 33 is fitted to the edge of the outer peripheral wall portion 31 of the shaft-side main body 21.

[0074] Therefore, in this Reference Example 2, the geared motor 49 is energized, causing the pressing portion 71 to press against the clutch ring 91 in the same manner as in Reference Example 1, and the female tapered surface 89 to be fastened to the male tapered surface 87.

[0075] In Reference Example 2, as in Reference Example 1, the target can be controlled, and the same effects and actions as in Reference Example 1 can be obtained.

[0076] Figure 4 is a cross-sectional view taken along the line IV-IV in Figure 5, relating to Example 1. Figure 5 is a cross-sectional view taken along the line VV in Figure 4, relating to Example 1. Components that are the same as or corresponding to those in Reference Example 1 are denoted by the same reference numerals and described accordingly, and redundant descriptions are omitted.

[0077] This embodiment 1 differs from reference example 1 in the configuration of the torque generating unit 13 and the transmission unit 15.

[0078] As shown in Figures 4 and 5, the torque generating unit 13 of this embodiment 1 is equipped to engage a cone clutch 86 similar to that in Reference Example 2, instead of the multi-plate clutch 81 of Reference Example 1.

[0079] The male tapered surface 87 of the cone clutch 86 is provided on the outer circumference 77 of the output rotating body 11. A pair of male tapered surfaces 87 are provided on the outer circumference 77 of the outer circumference 77 in an axially symmetrical manner. The outer circumference 77 of the output rotating body 11 is formed separately from the inner circumference 99.

[0080] The female tapered surface 89 is provided on the inner circumference of a pair of axially oriented clutch rings 91a and 91b. The clutch rings 91a and 91b are rotationally engaged with the bolt 41 on the housing 3 side. The back surface of one clutch ring 91a faces the pressing portion 71 of the movable pressing body 7 in the axial direction. The other clutch ring 91b is received with its back surface facing the housing 3 side in the axial direction.

[0081] The separated outer periphery 77 is positioned axially between the pressing portion 71 and the housing 3, with each male tapered surface 87 facing the female tapered surfaces 89 of the clutch rings 91a and 91b. The outer periphery 77 is rotationally engaged with the inner periphery 99 of the output rotating body 11 and loosely fitted radially.

[0082] The loose fitting of the outer circumference 77 is performed via an intermediate ring 101. The intermediate ring 101 is loosely fitted to both the outer circumference 77 and the inner circumference 99. The intermediate ring 101 is provided with a pair of inward protrusions 103 and a pair of outward protrusions 105 offset by 90 degrees. The inward protrusions 103 fit into an inward recess 107 provided on the outer circumference surface of the inner circumference 99, and the inward protrusions 103 and the inward recess 107 are engaged in the rotational direction and loosely fitted in the radial direction. The outward protrusions 105 fit into an outward recess 109 provided on the inner circumference surface of the outer circumference 77, and the outward protrusions 105 and the outward recess 109 are engaged in the rotational direction and loosely fitted in the radial direction.

[0083] The inner circumference 99 of the output rotating body 11 is provided with positioning plates 111 on both sides in the axial direction. The outer circumference of the positioning plates 111 is formed to have a larger diameter than the inner circumference 99. The two positioning plates 111 sandwich the intermediate ring 101 in the axial direction, and position the intermediate ring 101 in the axial direction. The inner circumferences of both positioning plates 111 have protruding edges that are axially outward from each other. The protruding edge of one positioning plate 111 abuts axially against the stopper ring 107 fitted into the output rotating body 11. The protruding edge of the other positioning plate 111 abuts axially against the inner race of the ball bearing 75a.

[0084] An axial oil hole 113 is formed at the inner end of the output rotating body 11, and a radial oil hole 115 is formed in the back of this oil hole 113 on the side of the friction torque output shaft 9. The oil hole 115 opens between the ball bearing 75a and the oil seal 93.

[0085] A flange member 117, which connects to the side to be braked, is spline-connected to the outer end of the friction torque output shaft 9 and is fastened and secured with a nut 119 that screws onto the male threaded portion 97.

[0086] In this embodiment 1, the transmission unit 15 has a movable pressing body 7 whose inner circumference 65 is spline-fitted to its outer circumference 69. This spline fitting is crimped on one axial side between the inner circumference 65 and the outer circumference 69. An oil seal 121 is interposed between the reduction output shaft 47 and the motor-side wall portion 37 of the housing 3.

[0087] The housing 3, as in Reference Example 2, has a configuration in which the motor-side main body 33 is fitted to the edge of the outer peripheral wall portion 31 of the shaft-side main body 21.

[0088] Therefore, in this embodiment 1, the pressing portion 71 presses against one of the clutch rings 91a in the same manner as in reference example 1 when the geared motor 49 is energized. The clutch ring 91a presses against the outer circumference 77 of the output rotating body 11 in the axial direction, and the outer circumference 77 comes into contact with the other clutch ring 91b. This contact fastens the pair of female tapered surfaces 89 of the torque generating portion 13 to the pair of male tapered surfaces 87.

[0089] At this time, the clutch ring 91 and the inner circumference 99 can move relative to each other in the radial direction due to the loose fitting with the intermediate ring 101. This relative movement causes the clutch ring 91 to automatically center with respect to the inner circumference 99 when the female tapered surface 89 and the male tapered surface 87 are fastened together. This centering allows for accurate fastening between the female tapered surface 89 and the male tapered surface 87.

[0090] In Example 1, as in Reference Example 1, the target can be braked, and the same effects and actions as in Reference Example 1 can be obtained. [Explanation of Symbols]

[0091] 1. Friction Torque Output Device 3 Housing 5 Adjustment screw 7. Movable pressing element (adjustment plate) 9. Friction Torque Output Shaft (Output Shaft) 11. Output Rotating Body (Output Plate) 13 Torque generating section 15 Transmission Section 29 Receiving part 47 Deceleration output shaft 49 Geared motor 52 Electric motor 53 Reduction mechanism 55 Male threaded section 65 Inner circumference of the movable pressing body 67 Female thread section 69 Outer circumference of the movable pressing body 71 Pressing part 77 Outer circumference of the output rotating body 81 Multi-plate clutch 83 Inner Plate 85 Outer Plate 87 Male tapered surface 89 Female tapered surface 91, 91a, 91b clutch rings 99 Inner circumference

Claims

[Claim 1] A housing with an electric motor attached, An adjustment screw is rotatably disposed within the housing and has a male threaded portion, receiving rotational output from the electric motor via a reduction mechanism, and is coupled to the reduction mechanism so as to be movable in the axial direction, A movable pressing body having a female thread portion on its inner circumference that screws onto the male thread portion and a pressing portion on its outer circumference, wherein the pressing portion moves axially due to the rotation of the male thread portion, A friction torque output shaft rotatably supported in the housing, An output rotating body disposed within the housing and rotating together with the friction torque output shaft, A torque generating unit is positioned between the movable pressing body and the output rotating body, and receives the pressing force from the pressing part to frictionally engage the housing and the output rotating body. The system includes a transmission unit positioned between the adjustment screw and the housing, which transmits the thrust force generated in the adjustment screw by the reaction force acting on the pressing part to the housing. The torque generating section is provided with a male tapered surface and a female tapered surface facing each other so as to be able to fasten them together. The male tapered surface is provided on the outer circumference, which is formed separately from the inner circumference of the output rotating body. The separated outer periphery is positioned axially between the pressing portion and the receiving portion provided in the housing, and engages with the inner circumference of the output rotating body in the rotational direction and loosely fits in the radial direction. The female tapered surface is provided on the inner circumference of the clutch ring that engages with the housing in the rotational direction and faces the pressing portion in the axial direction. Friction torque output device.

Images