JP2016093047A - Motor with reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently transmit the rotating force of a rotary shaft to a worm shaft.SOLUTION: In a motor 10 with a reduction gear, a ball bearing 122 is fixed to a worm shaft 62, and a load transmission member 124 fixed to a gear housing 52 is adjacent to the other side in a first direction with respect to the ball bearing 122 and disposed in contact with the ball bearing 122. Due to this, when thrust load to the other side in the first direction is applied to the worm shaft 62, thrust load is transmitted to the gear housing 52 via the ball bearing 122 and load transmission member 124. By virtue of this, thrust load is restricted from being input to the rotation shaft 32 of a motor body 12. Accordingly, since the rotary shaft 32 and worm shaft 62 arranged on the same axis are restricted from being displaced such that they are bent into an approximately V-shape having a coupling device 90 as its initial point, rotating force of the rotary shaft 32 can efficiently be transmitted to the worm shaft 62.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a motor with a reduction gear.

  The motor device described in Patent Document 1 below includes a motor unit and a speed reduction unit. The rotating shaft of the motor unit and the worm shaft of the speed reducing unit are configured separately and are drivingly connected by a coupling device. Thereby, the diameter dimension of a rotating shaft can be made small, for example, and a motor part can be reduced in size.

JP 2008-2496 A

  However, the above motor device has room for improvement in the following points. That is, during operation of the motor unit, a thrust load along the axial direction of the worm shaft acts on the worm shaft. In this case, the thrust load is input to the end of the rotating shaft on the worm shaft side, and the end of the rotating shaft opposite to the worm shaft is supported by the bearing plate via the ball. For this reason, when an excessive thrust load is input to the rotating shaft, the rotating shaft and the worm shaft arranged on the same axis are substantially started from the portion of the coupling device where the rotating shaft and the worm shaft are connected. The rotating shaft tends to be displaced so as to be bent in a V shape. At this time, since the rotating shaft is rotated in a bent state, the rotational force of the rotating shaft cannot be efficiently transmitted to the worm shaft, and the rotation loss increases. Therefore, the motor device described above has room for improvement in this respect.

  In consideration of the above-described facts, an object of the present invention is to provide a motor with a reduction gear that can efficiently transmit the rotational force of a rotating shaft to a worm shaft.

  A motor with a speed reducer according to the present invention is housed in a motor body having a rotating shaft and a housing provided on one side in the axial direction of the rotating shaft, and is disposed coaxially with the rotating shaft and of the rotating shaft. A worm shaft having a base end portion driven and connected to one end portion in the axial direction; a speed reducer that decelerates rotation of the rotating shaft; and a worm shaft that is fixed to the worm shaft and is operated when the motor body is in operation A load transmission mechanism for transmitting a thrust load acting on the base end side of the housing to the housing.

  According to the motor with a reduction gear configured as described above, the housing is provided on one axial side of the rotation shaft of the motor body. A reduction gear is accommodated in the housing, and the reduction gear has a worm shaft. The worm shaft is arranged coaxially with the rotation shaft, and the base end portion of the worm shaft is drivingly connected to the end portion on one axial side of the rotation shaft. Thereby, rotation of a rotating shaft is transmitted to a reduction gear by a worm shaft, and is decelerated by a reduction gear.

  Here, a load transmission mechanism is fixed to the base end side of the worm shaft. Then, a thrust load acting on the base end side of the worm shaft during operation of the motor body is transmitted to the housing by the load transmission mechanism. For this reason, it is suppressed that the said thrust load is input into the edge part of the axial direction one side of a rotating shaft. Thereby, it is suppressed that the rotating shaft and the worm shaft arranged coaxially are displaced so as to be bent in a substantially V shape starting from the connecting portion between the rotating shaft and the worm shaft. Therefore, the rotational force of the rotating shaft can be efficiently transmitted to the worm shaft.

  In the motor with a reduction gear according to the present invention, in addition to the above configuration, the worm shaft has a proximal end fixed to the load transmission mechanism and a distal end supported by a worm shaft side bearing, and the rotating shaft It is preferable that both end portions in the axial direction are pivotally supported by a rotary shaft side bearing, and the rotary shaft side bearing that pivotally supports one end portion in the axial direction is an alignment bearing.

  According to the above configuration, both axial ends of the worm shaft are pivotally supported by the load transmission mechanism and the worm shaft side bearing. Further, both end portions in the axial direction of the rotary shaft are supported by the rotary shaft side bearings. And the rotating shaft side bearing which pivotally supports the edge part of the axial direction one side of a rotating shaft is made into the alignment bearing. For this reason, the axial deviation which arises between the rotating shaft with which the axial direction both ends were supported, and the worm shaft can be absorbed by the alignment bearing.

  Further, in the motor with a reduction gear according to the present invention, in addition to the above configuration, the rotating shaft and the worm shaft are drivingly connected by a coupling device, and the coupling device is configured to be able to rotate integrally with the rotating shaft. A first coupling member formed, a second coupling member configured to be rotatable integrally with the worm shaft, and having elasticity, and interposed between the first coupling member and the second coupling member. And a damper member that transmits the rotational force of the first coupling member to the second coupling member.

  According to the above configuration, the rotating shaft and the worm shaft are drivingly connected by the coupling device. For this reason, for example, an impact between the first and second coupling members that occurs when the motor main body operates (particularly when rotation starts) can be absorbed by the damper member of the coupling device.

  In the motor with a reduction gear according to the present invention, in addition to the above configuration, the load transmission mechanism includes a bearing in which an inner ring is fixed to the worm shaft, and a cylindrical shape in which the second coupling member is accommodated. And a load transmitting member that is disposed adjacent to the rotary shaft side with respect to the bearing and is fixed to the housing and axially fixes an outer ring of the bearing to the housing; It is preferable that it is comprised including.

  According to the said structure, the load transmission mechanism is comprised including the bearing and the load transmission member. Then, the bearing is fixed to the worm shaft by fixing the inner ring of the bearing to the worm shaft. The load transmitting member is disposed adjacent to the bearing on the rotating shaft side, and is fixed to the housing to fix the outer ring of the bearing to the housing in the axial direction. Thereby, the said thrust load can be transmitted to a housing via a bearing and a load transmission member.

  Moreover, the load transmission member is formed in a cylindrical shape, and the second coupling member is accommodated in the load transmission member. For this reason, a 2nd coupling member can be arrange | positioned using the space inside a load transmission member. Thereby, while being able to implement | achieve an efficient arrangement structure with respect to a load transmission mechanism and a coupling apparatus, it can contribute to size reduction of a motor with a reduction gear.

It is sectional drawing seen from the 2nd orthogonal direction one side which shows the principal part of the motor with a reduction gear which concerns on this Embodiment. It is sectional drawing seen from the 2nd orthogonal direction one side which shows the whole motor with a reduction gear which concerns on this Embodiment. It is the disassembled perspective view seen from the 1st direction other side which shows the coupling apparatus and load transmission mechanism which are shown by FIG. It is the perspective view seen from the 1st direction one side which shows the 1st coupling member shown by FIG. It is sectional drawing which looked at the coupling apparatus shown by FIG. 2 from the 1st direction. It is explanatory drawing for demonstrating the displacement of a rotating shaft when a thrust load acts in the motor with a reduction gear of a comparative example, and a worm shaft.

  Hereinafter, the reduction gear-equipped motor 10 according to the present embodiment will be described with reference to the drawings. The motor 10 with a reduction gear is used as a drive source (a motor for a rear wiper in the present embodiment) of a wiper device of a vehicle (automobile), for example. As shown in FIG. 2, the motor 10 with a speed reducer includes a motor body 12 and a speed reducer 50 for reducing the rotation of the motor body 12. In addition, the motor 10 with a reduction gear includes a coupling device 90 for connecting the rotating shaft 32 of the motor body 12 and the worm shaft 62 of the reduction device 50, and a thrust load acting on the worm shaft 62. And a load transmission mechanism 120 to be transmitted to the housing 52. Hereafter, each said structure is demonstrated.

  In the drawings, the axial direction (hereinafter referred to as the first direction) of the motor main body 12 (rotational shaft 32) is indicated by arrows A and B, and the direction orthogonal to the axial direction of the motor main body 12 (hereinafter referred to as the first direction). (Referred to as the first orthogonal direction) is indicated by arrows C and D. Further, a direction orthogonal to the first orthogonal direction as viewed from the axial direction of the motor body 12 (the vertical direction in FIG. 2) is referred to as a second orthogonal direction. In the following description, the direction of arrow A is referred to as one direction in the first direction and the other direction in the first direction in the direction of arrow B. Further, the arrow C direction is referred to as one of the first orthogonal directions. Further, the upper side in FIG. 2 is referred to as one in the second orthogonal direction, and the lower side in FIG. 2 is referred to as the other in the second orthogonal direction.

(About motor body 12)
As shown in FIG. 2, the motor body 12 is configured as a so-called brushed DC motor. The motor body 12 includes a motor yoke 14, an armature 30, and a brush device 42.

  The motor yoke 14 is formed in a substantially bottomed cylindrical shape opened to one side in the first direction. A plurality of permanent magnets 16 are fixed to the inner peripheral surface of the motor yoke 14, and the permanent magnets 16 are arranged so that the magnetic poles of the permanent magnets 16 are alternately different along the circumferential direction of the motor yoke 14. Yes.

  A flange portion 14A is integrally formed at the opening end of the motor yoke 14, and the flange portion 14A extends radially outward of the motor yoke 14 and is arranged with the first direction as the plate thickness direction. Yes. A bearing recess 14B is formed at the bottom wall portion of the motor yoke 14 at the axial center of the motor yoke 14, and the bearing recess 14B protrudes from the bottom wall portion of the motor yoke 14 to the other side in the first direction. In addition, it is formed in a bottomed cylindrical shape opened to one side in the first direction. A bearing metal 18 as a “rotating shaft side bearing” having a substantially cylindrical shape is provided in the bearing recess 14B, and the bearing metal 18 is fixed to the motor yoke 14 with the first direction as an axial direction. A substantially disc-shaped bearing plate 20 is provided in the bearing recess 14B, and the bearing plate 20 is in contact with the bottom surface of the bearing recess 14B with the first direction as the plate thickness direction.

  The armature 30 includes a rotating shaft 32 that constitutes an axial center of the armature 30, an armature core 36, an armature coil 38, and a commutator 40, and is rotatably accommodated in the motor yoke 14. ing. The rotating shaft 32 is arranged coaxially with the motor yoke 14. Then, the end of the rotation shaft 32 on the other side in the first direction is rotatably supported by the bearing metal 18 and the end surface on the other side in the first direction of the rotation shaft 32 is a steel ball 22. Is supported by the bearing plate 20 from the other side in the first direction. Accordingly, the first ball 22 and the bearing plate 20 are configured to receive the thrust load generated on the rotating shaft 32 toward the other side in the first direction.

  On the other hand, the end portion on one side in the first direction (one side in the axial direction) of the rotating shaft 32 is rotatably supported by an alignment bearing 34 as a “rotating shaft side bearing” provided in a brush holder 44 described later. Yes. The alignment bearing 34 is configured to be aligned so that the inclination of the rotation shaft 32 with respect to the axis AL of the rotation shaft 32 can be adjusted. Specifically, as shown in FIG. 1, the outer peripheral surface of the alignment bearing 34 is formed in a spherical shape. Further, the brush holder 44 is formed with a fitting portion 45 into which the alignment bearing 34 is fitted, and the inner peripheral surface of the fitting portion 45 has a spherical shape corresponding to the outer peripheral surface of the alignment bearing 34. Is formed. The alignment bearing 34 is fitted into the fitting portion 45, and the alignment bearing 34 is held so as to be able to roll with respect to the brush holder 44.

  As shown in FIG. 3, a connecting shaft portion 32 </ b> A is integrally formed at an end portion on one side in the first direction of the rotating shaft 32. The connecting shaft portion 32A is disposed coaxially with the rotary shaft 32 and is formed in a substantially rectangular shape in cross section having a D-shaped cross section or two parallel planes.

  As shown in FIG. 2, the armature core 36 is fixed to the rotating shaft 32 and is formed by laminating a plurality of plate-shaped iron core single plates having a plurality of teeth. Then, the armature coil 38 is formed by successively winding the windings in predetermined slots of the armature core 36 in multiple turns.

  The commutator 40 is formed in a substantially cylindrical shape, and is press-fitted and fixed to the rotary shaft 32 at a position on one side in the first direction with respect to the armature core 36. In this commutator 40, a plurality of commutator pieces 40 </ b> A are arranged along the circumferential direction of the rotating shaft 32, and the adjacent commutator pieces 40 </ b> A are electrically insulated from each other. And the coil | winding wound by the predetermined slot of the armature coil 38 is electrically connected to each commutator piece 40A sequentially.

  The brush device 42 has a brush holder 44, and the brush holder 44 is made of an insulating resin material. The brush holder 44 includes a holder main body portion 44A formed in a substantially cylindrical shape and a connector portion 44B disposed on one side in the first orthogonal direction with respect to the holder main body portion 44A. Then, the holder main body 44A is fitted into the opening end of the motor yoke 14, and is clamped and fixed between the flange 14A of the motor yoke 14 and a holder cover 54 of the gear housing 52 described later. Yes. The brush device 42 includes a plurality of brushes 46, and the brushes 46 are disposed on the other side in the first direction of the holder main body 44 </ b> A and are disposed on the radially outer side of the commutator 40 of the armature 30. Yes. The brush 46 is pressed and abuts against the commutator 40 so as to be slidable.

(About the reducer 50)
The reduction gear 50 includes a gear housing 52 as a “housing”, and a reduction mechanism 60 and a clutch 70 housed in the gear housing 52.

  The gear housing 52 is made of metal (in this embodiment, made of an aluminum alloy), and is disposed on one side in the first direction with respect to the motor yoke 14. The gear housing 52 is formed in a substantially box shape opened to one side in the second orthogonal direction (the upper side in FIG. 2), and the opening of the gear housing 52 is closed by a cover (not shown).

  The gear housing 52 is integrally formed with a holder cover portion 54 for covering the brush holder 44 described above. The holder cover portion 54 is disposed at a position facing the opening of the motor yoke 14 described above, and is formed in a substantially bottomed cylindrical shape opened to the other side in the first direction. The outer peripheral portion of the holder cover portion 54 is fixed to the flange portion 14A of the motor yoke 14 so that the outer peripheral portion of the holder main body portion 44A of the brush device 42 is sandwiched and fixed, while the opening portion of the motor yoke 14 is closed. Has been.

  As shown in FIG. 1, an accommodation hole 56 for accommodating a coupling device 90 and a load transmission mechanism 120 described later is formed in the bottom wall portion of the holder cover portion 54 in the axial direction of the rotary shaft 32. The housing hole 56 has a substantially circular cross section. Further, as shown in FIG. 2, the gear housing 52 is formed with a shaft housing portion 58 for housing a worm shaft 62 described later at a position on one side in the first direction with respect to the housing hole 56. The shaft accommodating portion 58 is formed in a concave shape opened to one side in the second orthogonal direction, extends along the axial direction of the rotating shaft 32, and communicates with the accommodating hole 56. A stopper wall 56 </ b> A is formed at a boundary portion of the accommodation hole 56 with the shaft accommodation portion 58. The stopper wall 56 </ b> A is formed in a substantially ring shape, and the accommodation hole 56 is formed from the inner peripheral surface of the accommodation hole 56. Projecting radially inward.

  The speed reduction mechanism 60 includes a worm shaft 62 and a worm wheel 68. The worm shaft 62 is disposed coaxially with the rotating shaft 32 and is accommodated in the shaft accommodating portion 58. The tip of the worm shaft 62 (one end in the first direction) is rotatably supported by a bearing metal 64 as a cylindrical “worm shaft side bearing” fixed to the gear housing 52. A resin plug 66 fixed to the gear housing 52 is provided on one side in the first direction with respect to the worm shaft 62. Thus, the plug 66 receives a thrust load acting on the worm shaft 62 in one direction in the first direction. On the other hand, the base end portion (the end portion on the other side in the first direction) of the worm shaft 62 is drivingly connected to the connecting shaft portion 32A of the rotating shaft 32 so as to be integrally rotatable by a coupling device 90 described later. Further, a gear 62 </ b> A is integrally formed on the outer peripheral portion of the worm shaft 62 in the intermediate portion in the axial direction.

  The worm wheel 68 is disposed adjacent to one side in the first orthogonal direction with respect to the worm shaft 62 with the second orthogonal direction as the axial direction, and is rotatably supported by the gear housing 52. A gear 68A is formed on the outer periphery of the worm wheel 68, and the gear 68A meshes with the gear 62A of the worm shaft 62.

  The clutch 70 is disposed on one side in the first direction with respect to the worm wheel 68, and is connected to the worm wheel 68 via a link mechanism 80. The clutch 70 has an output shaft 72 whose axial direction is the second orthogonal direction, and the output shaft 72 projects from the clutch 70 to the other side in the second orthogonal direction. Although not shown, the gear housing 52 is formed with a substantially cylindrical support portion protruding from the gear housing 52 to the other side in the second orthogonal direction, and the clutch 70 is accommodated in the support portion. At the same time, the output shaft 72 is rotatably supported by the support portion. The distal end portion of the output shaft 72 protrudes from the support portion to the other side in the second orthogonal direction, and the wiper arm of the wiper device is fixed to the distal end portion of the output shaft 72. When an excessive load is applied to the wiper arm, the clutch 70 is actuated so that the rotary shaft 32 is idled.

  Hereinafter, the structure of the link mechanism 80 and the clutch 70 will be briefly described. The link mechanism 80 includes a first link 82 and a second link 84. One end portion of the first link 82 is rotatably connected to a portion biased radially outward with respect to the axial center of the worm wheel 68, and the other end portion of the first link 82 is one end of the second link 84. It is connected to the part so as to be relatively rotatable.

  The clutch 70 is configured to rotate integrally with the second link 84, and to be engaged with the clutch plate 74 and engaged with the output shaft 72 so as to be rotatable integrally and movable in the axial direction. A plate (not shown) and a base plate (not shown) fixed to the output shaft 72 so as to be integrally rotatable are configured, and these plates are arranged coaxially with the output shaft 72. The clutch plate 74 is supported so as to be rotatable relative to the output shaft 72. Further, a compression spring is provided between the base plate and the engagement plate, and the engagement plate and the clutch plate 74 are engaged with each other by the urging force of the compression spring. As a result, during normal operation of the motor main body 12, the clutch plate 74, the engagement plate, and the output shaft 72 rotate together around the output shaft 72. When a load of a predetermined value or more is applied to the rotary shaft 32, the clutch 70 is operated, and the engagement plate moves in the axial direction away from the clutch plate 74 against the urging force of the compression spring. ing. Accordingly, the meshing engagement state between the clutch plate 74 and the engagement plate is released, and the clutch plate 74 and the engagement plate rotate relative to each other. As a result, the transmission of the rotational force of the rotary shaft 32 is disconnected by the clutch 70 between the speed reduction mechanism 60 and the output shaft 72.

(About coupling device 90)
As shown in FIG. 3, the coupling device 90 includes a first coupling member 92, a second coupling member 102, and a damper member 106.

  The first coupling member 92 is made of a resin material. The first coupling member 92 has a substantially cylindrical base portion 94, and the base portion 94 is arranged coaxially with the rotation shaft 32. As shown in FIG. 4, a substantially cylindrical boss 96 is integrally formed on the end surface on one side in the first direction of the base portion 94 in the axial center portion. In addition, a key hole 92A having a substantially rectangular cross section is formed through the shaft portion of the base portion 94 and the boss 96 along the first direction. The connecting shaft portion 32A of the rotating shaft 32 is inserted into the key hole 92A, and the first coupling member 92 is connected to the rotating shaft 32 so as to be integrally rotatable (see FIG. 1).

  A ball holding portion 92 </ b> B is formed on the tip surface of the boss 96. The ball holding portion 92B is formed in a concave shape opened to one side in the first direction, and is formed in a circular shape when viewed from the axial direction of the boss 96. A second ball 100 (see FIG. 3), which is a steel ball, is accommodated and held in the ball holding portion 92B, and the distal end of the connecting shaft portion 32A of the rotating shaft 32 is placed on the outer peripheral surface of the second ball 100. The surface and the inner peripheral surface of the ball holding portion 92B are in contact (see FIG. 1).

  Furthermore, a plurality of (three in the present embodiment) first rotation transmitting portions 98 are formed to protrude from one end of the base portion 94. The first rotation transmitting portion 98 is disposed on the radially outer side of the boss 96 and on the radially inner side of the outer peripheral surface of the base portion 94, and is disposed at regular intervals (every 120 °) in the circumferential direction of the base portion 94. Has been. Further, the first rotation transmission part 98 is formed in a columnar shape having a substantially trapezoidal cross section. Specifically, the pair of side surfaces of the first rotation transmission unit 98 are inclined so as to approach each other as they approach the rotation axis center side when viewed from the axial direction of the base portion 94. Further, the inner peripheral surface and the outer peripheral surface of the first rotation transmitting portion 98 are curved so as to be concentric with the outer peripheral surface of the base portion 94 when viewed from the axial direction of the base portion 94. Furthermore, the front end surface of the first rotation transmission unit 98 and the front end surface of the boss 96 are arranged flush with each other.

  As shown in FIG. 3, the second coupling member 102 is integrally formed at the base end portion of the worm shaft 62 by cold forging. The second coupling member 102 is formed in a substantially bottomed cylindrical shape opened to the other side in the first direction, and is arranged coaxially with the worm shaft 62. As a result, the second coupling member 102 is formed in a cup shape, and a recess formed in the second coupling member 102 is a coupling recess 102A. And the 1st rotation transmission part 98 in the 1st coupling member 92 is fitted in the coupling recessed part 102A (refer FIG. 5). The outer diameter of the second coupling member 102 is set to be approximately the same as the outer diameter of the first coupling member.

  As shown in FIG. 5, a plurality of (three in this embodiment) second rotation transmission portions 104 are integrally formed on the inner peripheral surface of the coupling recess 102 </ b> A in the second coupling member 102. Yes. The second rotation transmitting portion 104 protrudes from the inner peripheral surface of the coupling recess 102A toward the rotation axis center side, and extends from the bottom surface of the coupling recess 102A to the distal end surface of the second coupling member 102. It is formed along the axial direction 102. Similar to the first rotation transmission unit 98, the second rotation transmission unit 104 is formed in a substantially trapezoidal shape when viewed from the axial direction of the second coupling member 102. Specifically, the pair of side surfaces of the second rotation transmission unit 104 are inclined so as to approach each other as they approach the rotation axis center side when viewed from the axial direction of the second coupling member 102. Further, the inner peripheral surface of the second rotation transmission unit 104 is curved so as to be concentric with the outer peripheral surface of the second coupling member 102 when viewed from the axial direction of the second coupling member 102.

  The damper member 106 is made of a rubber material and is configured to be elastically deformable. The damper member 106 has a cylindrical core portion 108, and the core portion 108 is fitted between the boss 96 of the first coupling member 92 and the first rotation transmission portion 98. (See FIG. 5). The damper member 106 has six buffer portions 110. The buffer portions 110 project radially from the core portion 108 radially outward of the core portion 108, and are arranged at equal intervals (60 °) in the circumferential direction of the core portion 108. Thereby, the fitting member 112 is formed with six fitting recesses 112 </ b> A to 112 </ b> F opened to the outside in the radial direction of the core portion 108 between the buffer portions 110 adjacent in the circumferential direction of the core portion 108. . The buffer portion 110 is formed in a substantially trapezoidal shape when viewed from the axial direction of the core portion 108, similarly to the first rotation transmission portion 98. Specifically, the pair of side surfaces of the buffer portion 110 are inclined so as to approach each other as they go inward in the radial direction of the core portion 108 when viewed from the axial direction of the core portion 108. Further, the outer peripheral surface of the core portion 108 is curved so as to be concentric with the outer peripheral surface of the core portion 108 when viewed from the axial direction of the core portion 108.

  Further, as shown in FIG. 5, in the state where the core portion 108 is fitted between the boss 96 of the first coupling member 92 and the first rotation transmitting portion 98, the fitting recesses 112A, 112C, 112E 1st rotation transmission part 98 is each fitted.

  Further, the first rotation transmitting portion 98 of the first coupling member 92 is fitted into the coupling recess 102 </ b> A of the second coupling member 102 in a state where the damper member 106 is assembled to the first coupling member 92. In this state, the second rotation transmission unit 104 is fitted in the fitting recesses 112B, 112D, and 112F, respectively. That is, in this state, in the circumferential direction of the first coupling member 92 (second coupling member 102), the first rotation transmission unit 98 and the second rotation transmission unit 104 are alternately arranged via the buffer unit 110. It is configured. The state where the first coupling member 92 is assembled to the second coupling member 102 is referred to as a sub-assembly state. Furthermore, in the sub-assy state, the side surface of the buffer 110, the side surface of the first rotation transmission unit 98, and the side surface of the second rotation transmission unit 104 are in contact with each other. Further, as shown in FIG. 1, the second ball 100 is in contact with the bottom surface of the coupling recess 102 </ b> A in the second coupling member 102 in the sub-assy state. In the sub-assy state, the rotation shaft 32 and the worm shaft 62 are driven and connected by the coupling device 90 by inserting the connection shaft portion 32A of the rotation shaft 32 into the key hole 92A of the first coupling member 92. Are configured to rotate together.

(About load transmission mechanism 120)
As shown in FIGS. 1 and 3, the load transmission mechanism 120 includes a ball bearing 122 as a “bearing” and a load transmission member 124.

  As shown in FIG. 1, the ball bearing 122 is fixed to the worm shaft 62 so that the inner ring is press-fitted into the outer periphery of the worm shaft 62 and adjacent to the second coupling member 102 on one side in the first direction. ing. A gap is provided between the second coupling member 102 and the ball bearing 122 in the axial direction of the worm shaft 62. That is, the ball bearing 122 and the second coupling member 102 are set so as not to contact in the axial direction of the worm shaft 62. Further, the outer diameter of the ball bearing 122 is set larger than the outer diameter of the second coupling member 102.

  Then, after the ball bearing 122 is press-fitted into the worm shaft 62, the worm shaft 62 is inserted into the accommodation hole 56 of the gear housing 52 from the other side in the first direction to the one side in the first direction. The second coupling member 102 of the coupling device 90 is accommodated in the accommodation hole 56 while being assembled in the accommodation hole 56 of the housing 52. At this time, the end surface on one side in the first direction of the ball bearing 122 (the outer cylinder portion thereof) is in contact with the stopper wall 56 </ b> A of the gear housing 52.

  The load transmission member 124 is made of metal. The load transmitting member 124 includes a cylindrical cylindrical portion 124A that is set slightly larger than the outer dimension of the outer ring of the ball bearing 122, and a radially outer side of the cylindrical portion 124A from the other axial end of the cylindrical portion 124A. And a flange 124 extending in a substantially annular plate shape. The cylindrical portion 124 </ b> A is press-fitted into the accommodation hole 56 of the gear housing 52, and the load transmission member 124 is fixed to the gear housing 52. In this state, the cylindrical portion 124A is disposed adjacent to the other side in the first direction with respect to the ball bearing 122, and the end surface on one side in the first direction of the cylindrical portion 124A is on the other side in the axial direction of the outer ring of the ball bearing 122. It is contact | abutted to the end surface. Further, the flange 124 </ b> B is in contact with the bottom surface of the holder cover portion 54 of the gear housing 52. Thereby, the movement of the ball bearing 122 in the first direction is restricted by the load transmitting member 124 and the stopper wall 56 </ b> A of the gear housing 52. The cylindrical portion 124A is disposed coaxially with the worm shaft 62, and the second coupling member 102 is disposed inside the cylindrical portion 124A. A gap is provided between the cylindrical portion 124 </ b> A and the second coupling member 102 so that they do not contact each other in the radial direction of the worm shaft 62.

  When the load transmitting member 124 is press-fitted into the housing hole 56 of the gear housing 52, the load transmitting member 124 is inserted into the housing hole 56 of the gear housing 52 in the first direction after the worm shaft 62 is assembled to the gear housing 52. It press-fits in the 1st direction one side from the other side. Thereafter, before the armature 30 is assembled to the brush device 42, the first coupling member 92, the damper member 106, and the second ball 100 are assembled in the coupling recess 102A of the second coupling member 102 in the accommodated state. To the sub-assy state.

  Next, the operation and effect of the present embodiment will be described.

  In the motor 10 with the speed reducer configured as described above, the rotating shaft 32 of the motor body 12 and the worm shaft 62 of the speed reducer 50 are configured separately, and the rotating shaft 32 and the worm shaft 62 are coupled. The device 90 is drivingly connected so as to be integrally rotatable. Thereby, when the motor main body 12 is operated, the rotational force of the rotary shaft 32 is transmitted to the worm shaft 62 of the speed reducer 50. Then, the rotational force of the rotary shaft 32 is transmitted to the output shaft 72 via the speed reducer 50, and the output shaft 72 is reciprocated around its own axis.

  The speed reduction mechanism 60 of the speed reducer 50 includes a worm shaft 62 and a worm wheel 68. For this reason, when the motor main body 12 is operated, a thrust load along the first direction acts on the worm shaft 62.

  Here, the case where the thrust load to the other side in the first direction acts on the worm shaft 62 will be described in comparison with the motor with a reduction gear of the comparative example. Note that the motor with a reduction gear of the comparative example does not have the load transmission mechanism 120 of the present embodiment.

  In the motor with a reduction gear of the comparative example, when a thrust load in the other side in the first direction acts on the worm shaft 62, the thrust load is input to the rotary shaft 32 via the coupling device 90. Specifically, the thrust load is input from the worm shaft 62 through the second ball 100 of the coupling device 90 to the distal end surface of the connecting shaft portion 32A of the rotating shaft 32. For this reason, in the rotating shaft 32, the end surface on the other side in the first direction is supported by the first ball 22 and the bearing plate 20 from the other side in the first direction. As a result, when a relatively large thrust load is input to the rotary shaft 32, the rotary shaft 32 and the worm shaft 62 arranged on the same axis are substantially V from the coupling device 90 as shown in FIG. It tries to be displaced so that it bends into a letter shape. In this case, the rotation shaft 32 tends to be displaced in a direction inclined with respect to the original axis line AL, and the rotation shaft 32 is rotated in a bent state, so that the rotation efficiency of the rotation shaft 32 may be reduced. Further, since a relatively large thrust load is received by the first ball 22 and the bearing plate 20, the bearing plate 20 may be worn. Further, if the bearing plate 20 is worn, rattling occurs between the bearing plate 20 and the first ball 22 in the thrust direction, and thus there is a possibility that abnormal noise may be generated in the motor 10 with a reduction gear.

  On the other hand, in the present embodiment, the ball bearing 122 is fixed to the other side in the first direction of the worm shaft 62 in the inner ring. A load transmission member 124 fixed to the gear housing 52 is adjacent to the ball bearing 122 on the other side in the first direction and is in contact with the outer ring of the ball bearing 122.

  Therefore, when a thrust load in the other side in the first direction acts on the worm shaft 62, the thrust load is transmitted from the inner ring of the ball bearing 122 to the load transmission member 124 via the outer ring. Then, the thrust load transmitted to the load transmission member 124 is transmitted to the gear housing 52. Thereby, it is suppressed that a thrust load is input to the rotating shaft 32. As a result, it is possible to prevent the rotation shaft 32 and the worm shaft 62 arranged on the same axis from being displaced so as to be bent in a substantially V shape starting from the coupling device 90. Therefore, the rotational force of the rotating shaft 32 can be efficiently transmitted to the worm shaft 62.

  Furthermore, the thrust load is prevented from acting on the first ball 22 and the bearing plate 20 by suppressing the input of the thrust load to the rotating shaft 32. For this reason, it is possible to prevent the bearing plate 20 from being worn by the first balls 22 and to prevent the generation of abnormal noise in the motor 10 with a reduction gear. Furthermore, since the thrust load is suppressed from being input to the rotating shaft 32, it is possible to suppress an increase in the diameter of the rotating shaft 32 and to contribute to the miniaturization of the motor body 12.

  In the present embodiment, the end of one side of the rotating shaft 32 in the axial direction is supported by the alignment bearing 34. For this reason, the shaft misalignment that occurs between the rotating shaft 32 and the worm shaft 62, which are formed separately, can be absorbed by the alignment bearing 34 when they are coupled by the coupling device 90. Hereinafter, this point will be described.

  That is, in general, when two shafts whose both ends in the axial direction are supported by a bearing metal are connected to each other due to assembly errors or dimensional tolerances, Since the shaft cannot be adjusted in the radial direction, it is difficult to absorb the misalignment.

  On the other hand, in the present embodiment, since the end of one axial direction of the rotating shaft 32 is supported by the alignment bearing 34, the inclination of the rotating shaft 32 with respect to the axis AL of the rotating shaft 32 is adjusted. 34 can be adjusted. Thereby, even if a shaft misalignment occurs between the rotating shaft 32 and the worm shaft 62, the shaft misalignment can be absorbed by the alignment bearing 34. Therefore, in order to transmit the thrust load acting on the worm shaft 62 to the gear housing 52, the ball bearing 122 is fixed to the base end portion of the worm shaft 62, and both end portions in the axial direction of the worm shaft 62 are pivotally supported. Even so, the misalignment between the rotating shaft 32 and the worm shaft 62 can be absorbed by the alignment bearing 34.

  In the present embodiment, the rotating shaft 32 and the worm shaft 62 are connected by the coupling device 90. Specifically, the first coupling member 92 is coupled to the coupling shaft portion 32 </ b> A of the rotating shaft 32, and the second coupling member 102 is integrally provided at the proximal end portion of the worm shaft 62. In the state where the first coupling member 92 is assembled in the coupling recess 102A of the second coupling member 102, the first rotation transmitting portion 98 of the first coupling member 92 and the second coupling member 102 are second. An elastically deformable damper member 106 is interposed between the rotation transmitting unit 104 and the rotation transmitting unit 104. Thereby, the impact of the rotating shaft 32 and the worm shaft 62 can be absorbed by the coupling device 90 when the motor body 12 is operated.

  Moreover, in the coupling device 90, the damper member 106 is accommodated in the coupling recess 102A of the second coupling member 102. Therefore, when the rotary shaft 32 rotates, the buffer portion 110 of the damper member 106 is elastically deformed by the first rotation transmission portion 98 of the first coupling member 92 and the second rotation transmission portion 104 of the second coupling member 102 ( Even in the case of compression deformation, the buffer 110 can be prevented from being deformed radially outward of the coupling device 90. Thereby, it can suppress that the buffer part 110 hits the internal peripheral surface of the accommodation hole 56 of the gear housing 52. FIG.

  Further, in the load transmission mechanism 120 of the present embodiment, the cylindrical portion 124A of the load transmission member 124 is formed in a cylindrical shape, and the second coupling member 102 is disposed in the cylindrical portion 124A. For this reason, the 2nd coupling member 102 can be arrange | positioned using the space inside 124 A of cylinder parts. Thereby, while being able to implement | achieve efficient arrangement | positioning structure with respect to the load transmission mechanism 120 and the coupling apparatus 90, it can contribute to size reduction of the motor 10 with a reduction gear in a 1st direction.

  In the present embodiment, the second coupling member 102 is disposed in the cylindrical portion 124A. That is, the load transmission mechanism 120 and the coupling device 90 are configured to wrap in the first direction. Instead of this, the load transmission mechanism 120 and the coupling device 90 may be shifted in the first direction.

  In the present embodiment, the load transmission member 124 is press-fitted into the accommodation hole 56 of the gear housing 52 and fixed to the gear housing 52, but the method of fixing the load transmission member 124 is not limited to this. For example, the load transmission member 124 may be fixed to the load transmission member 124 with a fastening member or an adhesive.

  In the present embodiment, a plurality of the first rotation transmission portions 98 of the first coupling member 92 and the second rotation transmission portions 104 of the second coupling member 102 are provided (three in this embodiment). However, the 1st rotation transmission part 98 and the 2nd rotation transmission part 104 are good also as one place.

DESCRIPTION OF SYMBOLS 10 ... Motor with reduction gear, 12 ... Motor body, 18 ... Bearing metal (rotating shaft side bearing), 32 ... Rotating shaft, 34 ... Centering bearing (Rotating shaft side bearing), 50 ... reducer, 52 ... gear housing (housing), 62 ... worm shaft, 64 ... bearing metal (worm shaft side bearing), 90 ... coupling device, 92 ... first DESCRIPTION OF SYMBOLS 1 coupling member, 102 ... 2nd coupling member, 106 ... Damper member, 120 ... Load transmission mechanism, 122 ... Ball bearing (bearing), 124 ... Load transmission member

Claims (4)

A motor body having a rotating shaft;
A worm housed in a housing provided on one axial side of the rotary shaft and disposed coaxially with the rotary shaft and having a base end driven and connected to an end on the one axial side of the rotary shaft A speed reducer that has a shaft and decelerates rotation of the rotating shaft;
A load transmission mechanism that is fixed to the worm shaft and transmits a thrust load acting on a proximal end side of the worm shaft to the housing when the motor body is operated;
A motor with a reduction gear. The base end side of the worm shaft is fixed to the load transmission mechanism, and the tip end is pivotally supported by a worm shaft side bearing,
The reduction shaft according to claim 1, wherein both end portions in the axial direction of the rotating shaft are pivotally supported by a rotating shaft side bearing, and the rotating shaft side bearing that pivotally supports one end portion in the axial direction is an alignment bearing. Motor with machine. The rotating shaft and the worm shaft are drivingly coupled by a coupling device,
The coupling device includes:
A first coupling member configured to rotate integrally with the rotating shaft;
A second coupling member configured to rotate integrally with the worm shaft;
A damper member having elasticity and interposed between the first coupling member and the second coupling member, and transmitting a rotational force of the first coupling member to the second coupling member;
The motor with a reduction gear according to claim 1 or 2, comprising the motor. The load transmission mechanism is
A bearing having an inner ring fixed to the worm shaft;
It has a cylindrical shape in which the second coupling member is accommodated, and is disposed adjacent to the rotary shaft side with respect to the bearing, and is fixed to the housing and has an outer ring of the bearing. A load transmission member fixed in an axial direction with respect to the housing;
The motor with a reduction gear according to claim 3, comprising: