JP7215374B2 - motor - Google Patents

Description

The present disclosure relates to motors.

2. Description of the Related Art Conventionally, there is a motor in which a rotating shaft to be rotated and a worm shaft arranged coaxially with the rotating shaft are connected by a clutch so as to be integrally rotatable. For example, in the motor disclosed in Patent Literature 1, the clutch connects the rotating shaft and the worm shaft via a connecting member so that they can rotate together. The rotary shaft has a drive-side insertion portion that is inserted into a drive shaft insertion hole provided in the connecting member. The driving-side insertion portion has a width across flat shape having an outer peripheral surface having a pair of flat portions parallel to each other and a pair of curved surface portions positioned between the pair of flat portions. The drive shaft insertion hole has an inner peripheral surface having a pair of connecting plane portions parallel to each other and a pair of connecting curved surface portions positioned between the pair of connecting plane portions. It has a width across flat shape that is one size larger. Therefore, the width across flat portion of the driving side insertion portion is loosely fitted into the drive shaft insertion hole. Further, each connecting flat portion of the drive shaft insertion hole is covered with a drive-side elastic member having elasticity from one end to the other end in the circumferential direction of each connecting flat portion. The drive-side elastic member presses the flat portion of the width across flat portion radially inward. Therefore, when the motor is assembled, the connecting member attached to the tip of the rotating shaft is elastically held by the drive-side elastic member so as not to fall off the rotating shaft. Therefore, workability in assembling the motor is improved.

Further, in the motor described in Patent Document 1, even if there is an axial misalignment between the rotating shaft and the connecting member due to an error in the assembly part, the width across flat portion of the driving side insertion portion is driven. The shaft misalignment is allowed because it is loosely fitted in the shaft insertion hole. In this case, the drive-side elastic member is elastically deformed to allow relative movement of the width across flats portion in the radial direction with respect to the drive shaft insertion hole. Therefore, it is possible to prevent a large radial load from being applied to the connecting portion between the rotating shaft and the connecting member when the rotating shaft rotates. As a result, when the rotating shaft rotates, it is possible to suppress the occurrence of large abnormal noise and vibration at the connecting portion between the rotating shaft and the connecting member.

JP 2003-278784 A

By the way, in the motor described in Patent Document 1, the width across flat portion that engages with the drive shaft insertion hole in the rotational direction has a width across flat shape. It has corners that extend to When the width across flats portion engages the drive shaft insertion hole in the rotational direction during rotation of the rotary shaft, the corner portion is pressed against the drive-side elastic member. As a result, the corner portion is repeatedly pressed against the drive-side elastic member, which may cause the drive-side elastic member to rupture or otherwise deteriorate the durability of the drive-side elastic member.

An object of the present disclosure is to provide a motor capable of suppressing deterioration in durability of a drive-side elastic member provided on the inner peripheral surface of a drive shaft insertion hole.

The motor of the present disclosure includes a rotation shaft (24) to be rotated, a speed reduction mechanism (51) including a worm shaft (52) arranged coaxially with the rotation shaft, and the rotation shaft and the worm shaft. and a clutch (13) having a connecting member (62) for integrally rotatably connecting the rotating shaft, the rotating shaft having a driving side insertion portion (31) at the tip of the rotating shaft, and the worm shaft: The worm shaft has a driven side insertion portion (102), and the connecting member has an inner peripheral surface into which the drive side insertion portion is inserted and the drive side insertion portion engages in the rotational direction. A shaft insertion hole (72) and a driven shaft insertion hole (75) having an inner peripheral surface into which the driven side insertion portion is inserted and with which the driven side insertion portion engages in the rotational direction, and the drive side insertion portion is , a width across flat shape portion (32) having an outer peripheral surface having a pair of flat portions (32a) parallel to each other and a pair of curved surface portions (32b) positioned between the pair of flat portions (32). and the drive shaft insertion hole has an inner peripheral surface having a pair of connecting flat portions (72c) parallel to each other and a pair of connecting curved surface portions (72d) located between the pair of connecting flat portions. and has a width across flats hole portion (72a) into which the width across flats portion is inserted, and between the opposing flat portion and the connecting flat portion and the opposing curved surface portion and the connecting curved surface portion, a driving side allowance gap (G1) that allows radial movement of the driving side insertion portion in the drive shaft insertion hole is provided, and the connecting curved surface portion has elasticity. A drive-side elastic member (74) is provided for pressing the curved surface portion radially inward, and both circumferential ends of the connecting flat portion are exposed inside the drive shaft insertion hole.

According to the above aspect, the drive-side elastic members are not provided at both circumferential ends of the connecting flat portion where there is a high possibility that the corners of the boundary portion between the flat portion and the curved portion are pressed during rotation of the rotating shaft. do not have. Further, the drive-side elastic member is provided on the connecting curved surface portion, which is less likely to be pressed against the corner portion of the boundary portion between the flat portion and the curved surface portion during rotation of the rotating shaft. Therefore, when the rotating shaft rotates, the corners of the boundary portion between the flat portion and the curved portion are prevented from being pressed against the drive-side elastic member, thereby preventing the drive-side elastic member from being torn or the like. As a result, deterioration in durability of the drive-side elastic member provided on the inner peripheral surface of the drive shaft insertion hole can be suppressed.

According to the motor of the present disclosure, deterioration in durability of the drive-side elastic member provided on the inner peripheral surface of the drive shaft insertion hole can be suppressed.

Sectional drawing of the motor in one Embodiment. FIG. 2 is a partially enlarged cross-sectional view of a motor in one embodiment; FIG. 2 is a partially enlarged cross-sectional view of a motor in one embodiment; Sectional drawing of the connection member in one Embodiment. Sectional drawing of the connection member in one Embodiment. The top view which shows some connection members in one Embodiment. (a) and (b) are sectional views of the clutch in one embodiment. (a) and (b) are sectional views of the clutch in one embodiment. (a) and (b) are sectional views of the clutch in one embodiment. (a) to (d) are sectional views showing a part of the motor in one embodiment. Sectional drawing of the connection member in the example of a change. The top view which shows a part of connection member in the example of a change.

An embodiment of the motor will be described below.
As shown in FIG. 1 , the motor 10 includes a motor section 11 , a reduction section 12 and a clutch 13 .

[Configuration of motor part]
A yoke 21, which is the outer shell of the motor section 11, has a cylindrical shape with a bottom. The yoke 21 has a brim-shaped flange portion 21a extending from the opening-side end of the yoke 21 to the outer peripheral side. A permanent magnet 22 is fixed to the inner peripheral surface of the yoke 21 . An armature 23 is arranged inside the yoke 21 at a position inside the permanent magnets 22 . The armature 23 includes a rotating shaft 24, an armature core 25 fixed to the rotating shaft 24 so as to be able to rotate integrally, a coil 26 wound around the armature core 25, and a commutator 27 rotating integrally with the rotating shaft 24. and The rotating shaft 24 has a substantially columnar shape and is arranged in the central portion of the yoke 21 . A base end of the rotating shaft 24 is supported by a bearing 28 provided at the center of the bottom of the yoke 21 .

As shown in FIGS. 2 and 3 , the rotating shaft 24 has a drive-side insertion portion 31 at the distal end of the rotating shaft 24 . The drive-side insertion portion 31 includes a width across flat portion 32 having a width across flat shape chamfered in parallel from a cylindrical shape at the distal end of the rotating shaft 24 and a short portion of the width across flat portion 32 at the base end of the width across flat portion 32 . It has shoulders 33 protruding on both sides in the hand direction. The shoulder portion 33 is formed by providing the width across flat portion 32 at the tip portion of the rotary shaft 24 . The outer peripheral surface of the width across flats portion 32 includes a pair of planar portions 32a that extend in the axial direction X1 of the rotation shaft 24 and are parallel to each other, and a pair of curved portions 32b positioned between the pair of planar portions 32a. have. The "axial direction X1 of the rotating shaft 24" is a direction parallel to the central axis L1 of the rotating shaft 24, and is hereinafter simply referred to as "axial direction X1". The width across flats portion 32 has a longitudinal direction parallel to the plane portion 32a and a width direction perpendicular to the plane portion 32a when viewed from the axial direction X1. Each curved surface portion 32b connects the circumferential ends of the pair of flat surface portions 32a. In addition, each curved surface portion 32b has an arc shape that bulges toward the outer circumference when viewed from the axial direction X1. Further, each curved surface portion 32b has an arcuate shape with the same curvature as that of the shoulder portion 33, and the position in the radial direction is the same as the outer peripheral surface of the shoulder portion 33. As shown in FIG. Further, the width across flat portion 32 has a corner portion 32c extending in the axial direction at the boundary portion between the flat portion 32a and the curved portion 32b that are adjacent in the circumferential direction.

As shown in FIG. 1 , the armature core 25 is fixed to a portion of the rotating shaft 24 closer to the base end than the drive-side insertion portion 31 . The commutator 27 is fixed between the portion of the rotary shaft 24 to which the armature core 25 is fixed and the drive-side insertion portion 31 . Coil 26 is electrically connected to commutator 27 .

A brush holder 35 is fitted in the opening of the yoke 21 . The brush holder 35 has a holder main body 35a shaped to close the opening of the yoke 21, and a connector portion 35b located outside the flange portion 21a of the yoke 21 in the direction perpendicular to the axial direction X1. The holder main body 35a and the connector portion 35b are integrally formed.

The holder main body 35a holds a bearing 36 that supports the rotary shaft 24 together with the bearing 28 in the central portion of the holder main body 35a. The bearing 36 rotatably supports a portion of the rotary shaft 24 between the commutator 27 and the drive-side insertion portion 31 . The tip of the rotating shaft 24 protrudes outside the yoke 21 through the holder body 35a in the axial direction X1.

The holder main body 35 a holds a plurality of power supply brushes 37 that are in sliding contact with the outer peripheral surface of the commutator 27 . Also, the brush holder 35 holds a plurality of terminals 38 . Each brush 37 is electrically connected to a corresponding terminal 38 . One end of each terminal is exposed inside the connector portion 35b. An external connector (not shown) connected to an external power supply is connected to the connector portion 35b. Current supplied through the external connector is supplied to coil 26 via terminals 38 , brushes 37 and commutator 27 . As a result, the armature 23 rotates, that is, the rotating shaft 24 rotates.

[Structure of deceleration part]
The reduction section 12 has a gear housing 41 made of resin and a reduction mechanism 51 that is accommodated in the gear housing 41 and that reduces the rotation of the rotating shaft 24 .

The gear housing 41 has a fixed portion 41a to which the yoke 21 is fixed at a portion facing the motor portion 11 in the axial direction X1. The fixed portion 41a has an outer shape similar to that of the flange portion 21a when viewed from the axial direction X1. A fitting recess 41b that opens to the inside of the yoke 21 is formed in the fixed portion 41a. With the portion of the brush holder 35 protruding from the yoke 21 fitted in the fitting recess 41b, the fixing portion 41a and the flange portion 21a abutting on the fixing portion 41a from the axial direction X1 are fixed by screws 42. Thus, the yoke 21 is fixed to the gear housing 41 . That is, by fixing the yoke 21 and the gear housing 41 with the screws 42, the motor section 11 and the reduction section 12 are integrated.

A first housing recess 41c is recessed in the axial direction X1 at the center of the bottom of the fitting recess 41b in the gear housing 41 . Further, in the center of the bottom of the first accommodation recess 41c in the gear housing 41, a second accommodation recess 41d having a diameter smaller than that of the first accommodation recess 41c is recessed in the axial direction X1. Further, the gear housing 41 is formed with a worm housing portion 41e extending in the axial direction X1 from the center of the bottom of the second housing recess 41d. A substantially cylindrical worm shaft 52 is accommodated in the worm accommodating portion 41e. The worm shaft 52 is rotatably supported by a pair of bearings 43 and 44 respectively arranged at both ends of the worm accommodating portion 41e in the axial direction X1. The worm shaft 52 is arranged coaxially with the rotating shaft 24 by being supported by the bearings 43 and 44 . That is, the worm shaft 52 is arranged so that the central axis L1 of the rotating shaft 24 and the central axis L2 of the worm shaft 52 are aligned.

Further, the gear housing 41 is formed with a gear housing portion 41f adjacent to the worm housing portion 41e in a direction orthogonal to the axial direction X1. The gear housing portion 41f communicates with the worm housing portion 41e. A disk-shaped worm wheel 53 that meshes with the worm shaft 52 is rotatably accommodated in the gear accommodation portion 41f. The worm wheel 53 constitutes the reduction mechanism 51 together with the worm shaft 52 . An output shaft 54 extending in the axial direction of the worm wheel 53 is provided at the radially central portion of the worm wheel 53 so as to be rotatable together with the worm wheel 53 .

[Configuration of Clutch]
As shown in FIGS. 1 and 2, the clutch 13 that connects the rotating shaft 24 and the worm shaft 52 is housed inside the first housing recess 41c and the second housing recess 41d. The clutch 13 includes a clutch housing 61 , a connecting member 62 , a support member 63 , rolling elements 64 and driven rotating elements 65 .

The clutch housing 61 has a cylindrical shape. The clutch housing 61 has a brim-shaped fixed flange portion 61a extending radially outward at one axial end of the clutch housing 61 . The clutch housing 61 is inserted into the second housing recess 41d with the fixed flange portion 61a in contact with the bottom surface of the first housing recess 41c. Since the fixed flange portion 61a is fixed to the bottom surface of the first housing recess 41c, the clutch housing 61 is immovable in the axial direction X1 with respect to the gear housing 41 and rotates in the circumferential direction around the central axis L1 of the rotary shaft 24. incapably fixed. The "circumferential direction around the central axis L1 of the rotating shaft 24" is hereinafter simply referred to as "circumferential direction". A clutch housing 61 fixed to the gear housing 41 is arranged coaxially with the rotating shaft 24 and the worm shaft 52 .

As shown in FIGS. 2 and 4, the connecting member 62 has a shaft connecting portion 71 extending in the axial direction X1. The shaft connecting portion 71 has a substantially cylindrical shape with an outer diameter smaller than the inner diameter of the clutch housing 61 . A drive shaft insertion hole 72 extending in the axial direction X1 is formed in the radially central portion of the shaft connecting portion 71 . The drive shaft insertion hole 72 is formed from one axial end of the shaft connecting portion 71 on the side of the motor portion 11 to a substantially central portion of the coaxial connecting portion 71 in the axial direction. The drive shaft insertion hole 72 includes a width across flats hole portion 72a having a width across flats shape when viewed from the axial direction X1, and an enlarged diameter portion 72b positioned at the opening of the drive shaft insertion hole 72 on the motor portion 11 side. have The width across flats hole portion 72a and the enlarged diameter portion 72b are adjacent to each other in the axial direction X1.

As shown in FIGS. 4 to 6, the inner peripheral surface of the width across flats hole portion 72a is located between a pair of connecting flat portions 72c that are spaced apart in the radial direction and are parallel to each other. and a pair of connecting curved surface portions 72d. Each connecting plane portion 72c has a planar shape extending in the axial direction X1. Each connecting curved surface portion 72d connects the circumferential ends of the pair of connecting flat portions 72c. Each connecting curved surface portion 72d has an arcuate shape that is concave radially outward when viewed from the axial direction X1. When viewed from the axial direction X1, the width across flats hole portion 72a has a longitudinal direction parallel to the connecting plane portion 72c, and a lateral direction perpendicular to the connecting plane portion 72c. The length of the width across flats hole portion 72 a in the width across flats direction is longer than the length of the width across flats portion 32 of the drive-side insertion portion 31 in the width direction of the width across flats portion 32 . Furthermore, the longitudinal length of the width across flats hole portion 72a is longer than the length of the width across flats portion 32 in the longitudinal direction.

As shown in FIGS. 2 to 6, the enlarged diameter portion 72b is positioned closer to the motor portion 11 than the width across flats hole portion 72a, and is axially aligned with the opening of the width across flats hole portion 72a on the motor portion 11 side. Adjacent to X1. The enlarged diameter portion 72b has a shape that enlarges the diameter of the opening of the drive shaft insertion hole 72 on the motor portion 11 side. The radial size of the enlarged diameter portion 72 b is larger than the outer diameter of the shoulder portion 33 of the driving side insertion portion 31 . By providing the enlarged diameter portion 72b, an opening stepped portion 72e is formed at the end portion of the drive shaft insertion hole 72 on the motor portion 11 side. The opening stepped portion 72e has a planar boundary surface 72f that faces the motor portion 11 side and is orthogonal to the axial direction X1. 72 f of boundary surfaces are located in the drive shaft insertion hole 72 in the boundary of the enlarged diameter part 72b and the width across flats hole part 72a. The opening of the width across flats hole portion 72a on the side of the motor portion 11 is formed in the boundary surface 72f. The boundary surface 72f may not necessarily be a plane orthogonal to the axial direction X1, and may be a surface inclined with respect to the axial direction X1 or a surface having unevenness.

By inserting the drive side insertion portion 31 into the drive shaft insertion hole 72, the rotating shaft 24 and the connecting member 62 are connected so as to be rotatable together. Specifically, the width across flats portion 32 at the tip of the driving side insertion portion 31 is inserted into the width across flats hole portion 72a, and the shoulder portion 33 is inserted into the enlarged diameter portion 72b. The width across flats portion 32 is formed on both sides in the width across flats portion 32 in the longitudinal direction such that the flat portion 32a and the connecting flat portion 72c are radially opposed to each other on both sides in the width across flats portion 32, and on both sides in the lengthwise direction of the width across flats portion 32. is inserted into the width across flats hole portion 72a so that the curved surface portion 32b and the connecting curved surface portion 72d face each other in the radial direction.

In the drive shaft insertion hole 72, the length of the width across flats hole portion 72a in the width across flats direction is longer than the length of the width across flats portion 32 in the width direction of the width across flats portion 32, and the length of the width across flats hole portion 72a in the longitudinal direction is longer than that of the width across flats portion 32. The length is longer than the length of the width across flats portion 32 in the longitudinal direction. That is, the drive shaft insertion hole 72 is formed so that the dimension of the width across flats hole portion 72a is relatively larger than that of the width across flats portion 32 by a predetermined value. Therefore, between the inner peripheral surface of the drive shaft insertion hole 72 and the outer peripheral surface of the drive side insertion portion 31 , there is a drive side allowance gap that allows radial movement of the drive side insertion portion 31 within the drive shaft insertion hole 72 . A gap G1 is formed. The drive-side allowable gap G1 is formed at the longitudinal end of the drive shaft insertion hole 72 and the lateral end of the drive shaft insertion hole 72 . Specifically, the drive-side allowable gap G1 is formed between the flat portion 32a and the connecting flat portion 72c facing each other, and between the curved surface portion 32b and the connecting curved surface portion 72d facing each other. The drive-side allowable gap G1 is defined by the movement of the drive-side insertion portion 31 in the direction parallel to the connecting flat portion 72c within the drive shaft insertion hole 72 and the movement of the driving side inserting portion 31 in the drive shaft insertion hole 72 in a direction perpendicular to the connecting flat portion 72c. movement of the drive-side insertion portion 31 in the direction of

Since the length in the longitudinal direction of the width across flat portion 32 is shorter than the length in the transverse direction of the width across flat portion 72a, that is, the distance between the pair of connecting flat portions 72c, the width across flat portion 32 It can be engaged with the surface width hole portion 72a in the rotational direction. That is, when the flat portion 32a of the width across flat portion 32 abuts on the connecting flat portion 72c of the width across flat hole portion 72a, the drive side insertion portion 31 is engaged with the inner peripheral surface of the drive shaft insertion hole 72 in the rotational direction. possible. By engaging the drive-side insertion portion 31 with the inner peripheral surface of the drive shaft insertion hole 72 in the rotational direction, the drive-side insertion portion 31 and the connecting member 62 are connected so as to be integrally rotatable. Thus, the drive-side insertion portion 31 is loosely fitted in the drive shaft insertion hole 72 so as to be rotatable integrally with the connecting member 62 .

An elastic annular elastic member 73 is provided at the end of the connecting member 62 in the axial direction X1 and on the side of the outer opening of the drive shaft insertion hole 72 . The annular elastic member 73 is provided on the inner peripheral surface of the enlarged diameter portion 72b. Specifically, the annular elastic member 73 is provided on the outer peripheral side of the inner peripheral surface of the width across flats hole portion 72a in the enlarged diameter portion 72b. The annular elastic member 73 has an annular shape surrounding the outer periphery of the opening of the width across flats hole 72a on the side of the enlarged diameter portion 72b when viewed from the axial direction X1. The annular elastic member 73 has a pair of pressing portions 73a projecting radially inward from the inner peripheral surface of the annular elastic member 73 . The pressing portions 73a are formed one by one on both sides of the width across flats hole portion 72a on the boundary surface 72f. The radially inner end surface of each pressing portion 73a has an arcuate shape that bulges radially inward. In addition, each pressing portion 73a is located on the outer peripheral side of the connecting plane portion 72c when viewed from the axial direction X1. When the drive-side insertion portion 31 is not inserted into the drive shaft insertion hole 72, the distance between the one pressing portion 73a and the other pressing portion 73a is equal to the shoulder portion 33 of the drive-side insertion portion 31. shorter than the outer diameter. Each pressing portion 73a presses radially inwardly the shoulder portion 33 of the drive-side insertion portion 31 arranged in the enlarged diameter portion 72b. 6 shows the connecting member 62 in a state in which the drive-side insertion portion 31 is not inserted into the drive shaft insertion hole 72, and also shows the drive-side insertion portion 31 with a two-dot chain line.

A drive-side elastic member 74 that has elasticity and presses the drive-side insertion portion 31 radially inward is provided on the inner peripheral surface of the drive shaft insertion hole 72 . The drive-side elastic member 74 is provided on each of the connecting curved surface portions 72d positioned at both ends in the longitudinal direction of the width across flats hole portion 72a. That is, the drive-side elastic member 74 is provided on the inner peripheral surface of the drive shaft insertion hole 72 at the longitudinal end of the width across flats hole portion 72a. Each drive-side elastic member 74 is positioned at the center in the circumferential direction of the connecting curved surface portion 72d on which it is provided. The drive-side elastic members 74 are not provided at both circumferential ends of each connecting curved surface portion 72d. A portion of the inner peripheral surface of the drive shaft insertion hole 72 where the driving side elastic member 74 and the annular elastic member 73 are not formed is exposed inside the drive shaft insertion hole 72 . Therefore, both circumferential ends of each connecting curved surface portion 72 d are exposed inside the drive shaft insertion hole 72 . In other words, at both sides of the connecting curved surface portion 72d in the circumferential direction of the driving side elastic member 74, from the circumferential end of the connecting curved surface portion 72d to the circumferential center side of the connecting curved surface portion 72d, the width in the circumferential direction is exposed inside the drive shaft insertion hole 72 . Furthermore, on the inner peripheral surface of the drive shaft insertion hole 72, the portion of the inner surface of the enlarged diameter portion 72b that is not covered with the annular elastic member 73 and the pair of connecting plane portions 72c are exposed inside the drive shaft insertion hole 72. are doing.

In each connecting curved surface portion 72d, the drive-side elastic member 74 protrudes radially inward from the corresponding connecting curved surface portion 72d. Further, the drive-side elastic member 74 forms a ridge continuously extending along the axial direction X1. Further, the drive-side elastic member 74 extends continuously from one end to the other end in the axial direction X1 in a range radially overlapping the width across flat portion 32 of the connecting curved surface portion 72d. In this embodiment, the connecting curved surface portion 72d radially overlaps the width across flat portion 32 from one end to the other end in the axial direction X1 of the connecting curved surface portion 72d. It extends continuously from one end to the other end in the axial direction X1 of 72d. The axial direction X<b>1 end of each drive-side elastic member 74 on the enlarged diameter portion 72 b side is continuous with the annular elastic member 73 .

A radially inner end surface of each drive-side elastic member 74 has an arc shape that expands radially inward when viewed from the axial direction X1. When the drive-side insertion portion 31 is not inserted into the drive shaft insertion hole 72, the distance between one drive-side elastic member 74 and the other drive-side elastic member 74 is equal to the width across flat portion 32. shorter than its longitudinal length. Therefore, when the drive-side insertion portion 31 is inserted into the drive shaft insertion hole 72, each drive-side elastic member 74 presses the curved surface portion 32b of the width across flat portion 32 radially inward. In this manner, since the drive-side elastic member 74 presses the drive-side insertion portion 31 radially inward, when the connecting member 62 is attached to the rotary shaft 24 during assembly of the motor 10 , the drive-side elastic member 74 connects the rotating shaft 24 . The member 62 is elastically held so as not to fall off the rotary shaft 24 . Therefore, workability in assembling the motor 10 is improved.

As shown in FIGS. 2 to 5, a driven shaft insertion hole 75 extending in the axial direction of the coaxial connecting portion 71 is formed in the radially central portion of the shaft connecting portion 71 . The driven shaft insertion hole 75 is formed from one end of the shaft connecting portion 71 on the speed reducing portion 12 side to a substantially central portion of the coaxial connecting portion 71 in the axial direction. The driven shaft insertion hole 75 communicates with the drive shaft insertion hole 72 .

As shown in FIG. 7B, the driven shaft insertion hole 75 has a width across flat shape when viewed from the axial direction X1. The inner peripheral surface of the driven shaft insertion hole 75 is positioned between a pair of drive-side transmission surfaces 75a that are spaced apart in the radial direction and are parallel to each other, and between the pair of drive-side transmission surfaces 75a. It has two connection surfaces 75b that connect each other. The driven shaft insertion hole 75 has a longitudinal direction parallel to the drive-side transmission surface 75a and a lateral direction perpendicular to the drive-side transmission surface 75a when viewed from the axial direction X1. That is, the driven shaft insertion hole 75 has a shape having a lateral direction and a longitudinal direction when viewed from the axial direction X1. Also, the center axis of the driven shaft insertion hole 75 coincides with the center axis of the drive shaft insertion hole 72 . Furthermore, the driven shaft insertion hole 75 is shifted by 90° from the drive shaft insertion hole 72 in the rotational direction of the connecting member 62 . That is, the longitudinal direction of the driven shaft insertion hole 75 is deviated from the longitudinal direction of the width across flats hole portion 72a by 90° in the rotational direction of the connecting member 62 . Note that the rotation direction of the connecting member 62 is the same as the rotation direction of the rotating shaft 24 . Therefore, when the connecting member 62 is viewed from the axial direction X1, the center line M1 of the drive shaft insertion hole 72 extending in the longitudinal direction through the center of the width across flats hole portion 72a of the drive shaft insertion hole 72 is the driven shaft. It intersects perpendicularly with the center line M2 of the driven shaft insertion hole 75 extending in the longitudinal direction through the center of the insertion hole 75 in the lateral direction.

A first driven-side elastic member 76 made of an elastic material is provided on the inner peripheral surface of the driven shaft insertion hole 75 at the end in the longitudinal direction, that is, the connecting surface 75b. Each of the first driven-side elastic members 76 extends along the axial direction X1 at the central portion in the lateral direction of the driven shaft insertion hole 75 in the connecting surface 75b. Each first driven-side elastic member 76 protrudes inside the driven shaft insertion hole 75 from the connecting surface 75b.

A second driven-side elastic member 77 made of an elastic material is provided on each drive-side transmission surface 75a. The second driven-side elastic member 77 extends along the axial direction X1 at the longitudinal center of the driven shaft insertion hole 75 in each drive-side transmission surface 75a. Each second driven-side elastic member 77 protrudes inside the driven shaft insertion hole 75 beyond the drive-side transmission surface 75a.

As shown in FIGS. 3 and 5, an axial cushioning member 78 made of an elastic material is provided at the end of the driven shaft insertion hole 75 in the axial direction X1 on the drive shaft insertion hole 72 side. The axial cushioning member 78 is provided at the end of the driven shaft insertion hole 75 on the drive shaft insertion hole 72 side in the axial direction X<b>1 at a position on the outer peripheral side of the drive shaft insertion hole 72 . The axial cushioning member 78 protrudes toward the inside of the driven shaft insertion hole 75 in the axial direction X1.

A substantially annular collar portion 79 extending radially outward is integrally formed at the axial direction X1 end portion of the shaft connecting portion 71 on the driven shaft insertion hole 75 side. The outer diameter of the flange portion 79 is slightly larger than the inner diameter of the clutch housing 61 .

Two rolling element release portions 81 are formed integrally with the flange portion 79 . The two rolling element release portions 81 are formed on both longitudinal sides of the driven shaft insertion hole 75 . Each rolling element release portion 81 extends from the flange portion 79 along the axial direction X1 to the side opposite to the drive shaft insertion hole 72 . The two rolling element release portions 81 are formed at positions spaced apart by 180° in the circumferential direction.

As shown in FIGS. 3, 5, and 7A, each rolling element release portion 81 has a radially inner side surface, a circumferential both side surface, and a radially outer side surface. and the tip surface are covered with a shock absorbing member 82 made of an elastic material. The shape of the rolling element releasing portion 81 including the impact absorbing member 82 is a substantially rectangular plate-like shape in which the radially outer side surface is arcuate and the radially inner side surface is planar.

The impact absorbing member 82 , the annular elastic member 73 , the driving side elastic member 74 , the first and second driven side elastic members 76 and 77 , and the axial cushioning member 78 are the impact absorbing member 82 and the annular elastic member in the connecting member 62 . 73 , drive-side elastic member 74 , first and second driven-side elastic members 76 and 77 , and axial cushioning member 78 are formed integrally with parts made of a resin material. Further, in this embodiment, the annular elastic member 73, the driving side elastic member 74, the first and second driven side elastic members 76, 77, the axial cushioning member 78, and the impact absorbing member 82 are made of the same material. The annular elastic member 73, the drive-side elastic member 74, the first and second driven-side elastic members 76 and 77, the axial cushioning member 78, and the shock absorbing member 82 are made of elastomer containing rubber, for example. Furthermore, in the present embodiment, the annular elastic member 73, the driving side elastic member 74, the first and second driven side elastic members 76 and 77, the axial cushioning member 78, and the impact absorbing member 82 are all continuously integrated. formed.

The connecting member 62 is arranged with respect to the clutch housing 61 in a state in which the distal end portions of the two rolling element releasing portions 81 are inserted inside the clutch housing 61 . The shaft connecting portion 71 and the flange portion 79 are arranged outside the clutch housing 61 . Specifically, as shown in FIGS. 1 and 3 , the shaft connecting portion 71 and the flange portion 79 are arranged between the clutch housing 61 and the brush holder 35 . The tip of the rolling element release portion 81 arranged inside the clutch housing 61 faces the inner peripheral surface of the clutch housing 61 in the radial direction.

As shown in FIGS. 2 and 7A, the support member 63 is made of a resin material. The support member 63 has a ring portion 91 arranged between the fixed flange portion 61 a of the clutch housing 61 and the flange portion 79 of the connecting member 62 . The outer diameter of the ring portion 91 is smaller than the outer diameter of the fixed flange portion 61a. Also, the inner diameter of the ring portion 91 is larger than the inner diameter of the clutch housing 61 .

A pair of roller supports 92 are integrally formed with the ring portion 91 at two locations spaced apart in the circumferential direction of the ring portion 91 . In this embodiment, a pair of roller supports 92 are provided at two locations on the ring portion 91 that are spaced apart by 180° in the circumferential direction. The paired roller supports 92 extend in the axial direction X1 from the inner peripheral edge of the ring portion 91 and are spaced apart from each other in the circumferential direction. The tip portions of the two pairs of roller supports 92 are connected by a reinforcing portion 93 extending in an arc shape along the circumferential direction. At the tip of each roller support 92, a holding claw 94 projecting between the pair of roller supports 92 is formed.

An outer peripheral holding portion 95 and an inner peripheral holding portion 96 are provided on the circumferential side surfaces of the paired roller supports 92 that face each other. The outer peripheral side holding portions 95 are formed along the radially outer ends of the mutually facing side surfaces of the pair of roller supports 92 . The inner peripheral side holding portion 96 is formed along the radially inner end portions of the side surfaces facing each other. The outer peripheral side holding portion 95 and the inner peripheral side holding portion 96 protrude between the paired roller supports 92 . In addition, the outer peripheral side holding portion 95 and the inner peripheral side holding portion 96 have a triangular shape in which the cross section orthogonal to the axial direction X1 becomes narrower in the radial direction toward the intermediate portion of the paired roller supports 92 . ing. Note that each roller support 92 is elastically deformable so that its distal end is displaced in the circumferential direction with respect to its proximal end.

Rolling elements 64 are inserted in the two pairs of roller supports 92, respectively. Each rolling element 64 has a cylindrical shape. The two rolling elements 64 are each arranged between a pair of roller supports 92 . On the outer peripheral surface of each rolling element 64, the outer peripheral side holding portion 95 of the paired roller support 92 abuts from the outer peripheral side of the support member 63, and the inner peripheral side holding portion 96 abuts from the inner peripheral side of the support member 63. in contact with That is, each rolling element 64 is sandwiched by a pair of roller supports 92 . Each rolling element 64 is restricted from moving radially and circumferentially with respect to the support member 63 by the roller support 92 . Further, each rolling element 64 is held by a pair of roller supports 92 so as to be rotatable about the central axis of the rolling element 64 . Also, the two rolling elements 64 are held by the paired roller supports 92, respectively, so that their central axes are substantially parallel to each other and are arranged at substantially equal angular intervals in the circumferential direction. Further, each rolling element 64 is prevented from falling off from the support member 63 by a holding claw 94 .

As shown in FIGS. 2, 3 and 7(a), the support member 63 is arranged with respect to the clutch housing 61 in a state in which the roller support 92 holding the rolling elements 64 is inserted inside the clutch housing 61. be. The ring portion 91 contacts the fixed flange portion 61a from the motor portion 11 side. The two rolling element releasing portions 81 of the connecting member 62 are inserted inside the ring portion 91 , and the two rolling element releasing portions 81 are arranged between the two pairs of roller supports 92 . The support member 63 and the connecting member 62 are relatively rotatable in the circumferential direction. As shown in FIGS. 7A and 8A, when the connecting member 62 rotates with respect to the support member 63, each rolling element releasing portion 81 moves forward in the rotating direction from the rotating direction of the connecting member 62. It can abut on the roller support 92 located. Further, the outer peripheral surface of the rolling element 64 arranged inside the clutch housing 61 can come into contact with the inner peripheral surface of the clutch housing 61 .

As shown in FIGS. 2 and 3 , the driven rotating body 65 is formed at the base end of the worm shaft 52 . The driven-side rotating body 65 includes a driven-side control section 101 and a driven-side insertion section 102 arranged in the axial direction.

The driven side control portion 101 has a columnar shape extending in the axial direction of the worm shaft 52 at the base end portion of the worm shaft 52 . The center axis line of the driven side control section 101 coincides with the center axis line L2 of the worm shaft 52 . That is, the driven side control section 101 is formed coaxially with the worm shaft 52 . The outer diameter of the driven side control portion 101 is set to a value equal to or less than the maximum outer diameter of the worm shaft 52 . In this embodiment, the outer diameter of the driven side control portion 101 is equal to the outer diameter of the portion of the worm shaft 52 supported by the bearing 43 .

As shown in FIGS. 2 and 7A, a pair of control surfaces 103 are formed on the outer peripheral surface of the driven control section 101. As shown in FIG. The two control surfaces 103 are formed on the outer peripheral surface of the driven control portion 101 at two locations spaced apart by 180° in the circumferential direction, that is, at two locations spaced equiangularly in the circumferential direction. Each control surface 103 has a planar shape parallel to the axial direction of the worm shaft 52 . Furthermore, the pair of control surfaces 103 are parallel to each other. The axial length of the worm shaft 52 on each control surface 103 is longer than the axial length of the rolling elements 64 .

The driven-side insertion portion 102 is formed integrally with one of both ends of the driven-side control portion 101 in the axial direction X<b>1 that is farther from the center portion of the worm shaft 52 in the axial direction. That is, the driven-side insertion portion 102 is formed at a position farther from the tip of the worm shaft 52 than the driven-side control portion 101 . In addition, the driven-side insertion portion 102 and the driven-side control portion 101 are formed continuously in the axial direction X1. The driven-side insertion portion 102 has a columnar shape extending in the axial direction of the worm shaft 52 . The central axis of the driven-side insertion portion 102 coincides with the central axis L2 of the worm shaft 52 . That is, the driven-side insertion portion 102 is formed coaxially with the worm shaft 52 . The axial length of the driven side insertion portion 102 is slightly longer than the length of the driven shaft insertion hole 75 provided in the connecting member 62 in the axial direction X1. The outer diameter of the driven-side insertion portion 102 is set to a value equal to or less than the maximum outer diameter of the worm shaft 52 . In this embodiment, the outer diameter of the driven-side insertion section 102 is equal to the outer diameter of the driven-side control section 101 .

As shown in FIG. 7B, the driven-side insertion portion 102 has a substantially elliptical cross-sectional shape perpendicular to the axial direction X1, and the cross-sectional shape is constant in the axial direction X1. As shown in FIGS. 7A and 7B, when the driven-side insertion portion 102 is viewed from the axial direction X1, the longitudinal direction of the driven-side insertion portion 102 is parallel to the control surface 103 and , the lateral direction of the driven-side insertion portion 102 is a direction perpendicular to the control surface 103 . In addition, the longitudinal length of the driven side insertion portion 102 is shorter than the longitudinal length of the driven shaft insertion hole 75 when viewed from the axial direction X1. Furthermore, when viewed from the axial direction X1, the length of the driven side insertion portion 102 in the widthwise direction is shorter than the length of the driven shaft insertion hole 75 in the widthwise direction. The length of the driven-side insertion portion 102 in the axial direction X1 is slightly longer than the length of the drive-side transmission surface 75a provided on the inner peripheral surface of the driven shaft insertion hole 75 in the axial direction X1.

As shown in FIG. 7B, a pair of first driven-side transmission surfaces 104 and a pair of second driven-side transmission surfaces 105 are formed on the outer peripheral surface of the driven-side insertion portion 102 . One first driven-side transmission surface 104 of the pair of two first driven-side transmission surfaces 104 is formed on the opposite side of the other first driven-side transmission surface 104 by 180°. The two first driven-side transmission surfaces 104 each have a planar shape parallel to the axial direction X1 and are parallel to each other. Furthermore, the distance between the two first driven-side transmission surfaces 104 is equal to the distance between a pair of drive-side transmission surfaces 75 a provided on the inner peripheral surface of the driven shaft insertion hole 75 . Also, the second driven-side transmission surfaces 105 are formed between the two first driven-side transmission surfaces 104 respectively. One second driven-side transmission surface 105 is formed on the opposite side of the other second driven-side transmission surface 105 at an angle of 180°. The two second driven-side transmission surfaces 105 each have a planar shape parallel to the axial direction X1 and are parallel to each other. Furthermore, the spacing between the two second driven side transmission surfaces 105 is equal to the spacing between the pair of driving side transmission surfaces 75a. Each first driven-side transmission surface 104 and each second driven-side transmission surface 105 are formed in the axial direction X1 from one end to the other end of the driven-side insertion portion 102 in the axial direction X1.

As shown in FIGS. 2 and 7A, the driven rotating body 65 is inserted inside the clutch housing 61 and the support member 63 from the opposite side of the connecting member 62 . The driven-side insertion portion 102 is inserted into the driven shaft insertion hole 75 of the connecting member 62 . Also, the driven-side control unit 101 is arranged between the two rolling elements 64 held by the support member 63 . The driven-side rotating body 65 is arranged coaxially with the clutch housing 61 , the connecting member 62 and the support member 63 .

As shown in FIGS. 3 and 7B, the driven side insertion portion 102 is loosely fitted in the driven shaft insertion hole 75 so as to be rotatable integrally with the connecting member 62 . The driven-side insertion portion 102 is in contact with the axial cushioning member 78 in the axial direction X1. A first driven-side elastic member 76 and a second driven-side elastic member 77 are interposed between the outer peripheral surface of the driven-side insertion portion 102 and the inner peripheral surface of the driven shaft insertion hole 75, which face each other in the radial direction. . The pair of first driven-side elastic members 76 are in contact with the driven-side insertion portion 102 from both longitudinal sides of the driven shaft insertion hole 75 inside the driven shaft insertion hole 75 . The second driven-side elastic member 77 is in contact with the driven-side insertion portion 102 inside the driven shaft insertion hole 75 from both sides in the short direction of the driven shaft insertion hole 75 . Specifically, the second driven-side elastic member 77 is formed between the first driven-side transmission surface 104 and the second driven-side transmission surface 105 adjacent in the longitudinal direction of the driven-side insertion portion 102 on the outer peripheral surface of the driven-side insertion portion 102 . touching the part in between.

When the connecting member 62 rotates about the central axis of the connecting member 62 with respect to the driven rotating body 65, the first driven side transmission surface 104 and the second driven side transmission surface 105 are rotated according to the rotation direction of the connecting member 62. The drive-side transmission surface 75a that opposes one of the driven-side transmission surfaces abuts from the rotational direction. The driven-side insertion portion 102 is provided at either one of the first driven-side transmission surface 104 or the second driven-side transmission surface 105 and at both ends of the driven shaft insertion hole 75 in the width direction. When the drive-side transmission surface 75a abuts and engages in the rotational direction, the connecting member 62 and the unitary rotation become possible. That is, the connecting member 62 and the driven rotor 65 are engaged in the rotational direction, and the rotational driving force of the connecting member 62 is transmitted to the driven rotor 65 . Since the driving side insertion portion 31 of the rotary shaft 24 is inserted into the drive shaft insertion hole 72 of the connecting member 62 , the worm shaft 52 having the driven side insertion portion 102 and the rotary shaft 24 move through the connecting member 62 . It will be connected so as to be integrally rotatable.

As shown in FIG. 7B, the longitudinal length of the driven shaft insertion hole 75 is longer than the longitudinal length of the driven side insertion portion 102 when viewed from the axial direction X1. Furthermore, when viewed from the axial direction X1, the length of the driven shaft insertion hole 75 in the width direction is longer than the length of the width direction of the driven side insertion portion 102 . Therefore, between the inner peripheral surface of the driven shaft insertion hole 75 and the driven side insertion portion 102, there is a driven side allowable gap G2 that allows radial movement of the driven side insertion portion 102 in the driven shaft insertion hole 75. It is formed. That is, the driven-side allowable gap G2 is formed between the drive-side transmission surface 75a and the outer peripheral surface of the driven-side insertion portion 102, and between the connecting surface 75b and the outer peripheral surface of the driven-side insertion portion 102. When the driven-side insertion portion 102 moves in the driven-shaft insertion hole 75 in the longitudinal direction of the driven-shaft insertion hole 75 , the driven-side insertion portion 102 moves while elastically deforming the first driven-side elastic member 76 . When the driven-side insertion portion 102 moves in the driven-shaft insertion hole 75 in the lateral direction of the driven-shaft insertion hole 75 , the driven-side insertion portion 102 moves while elastically deforming the second driven-side elastic member 77 .

Next, the operation of the motor 10 configured as described above will be described, centering on the operation of the clutch 13. FIG.
As shown in FIG. 1, when the motor portion 11 is stopped, that is, when the rotary shaft 24 is not rotating, when a load connected to the output shaft 54 is applied to the output shaft 54, the worm shaft 52 rotates due to the load. try to. Therefore, the driven side rotating body 65 tries to rotate. Then, as shown in FIG. 7A, each control surface 103 of the driven rotor 65 pushes the rolling element 64 arranged between each control surface 103 and the inner peripheral surface of the clutch housing 61 to the outer peripheral side. press. The rolling element 64 pushed by the control surface 103 elastically deforms the roller support 92 that holds the rolling element 64 , pushes the outer peripheral holding portion 95 open to both sides in the circumferential direction, and moves to the outer peripheral side to move to the clutch housing 61 . abuts on the inner peripheral surface of Each control surface 103 sandwiches the rolling element 64 arranged between each control surface 103 and the inner peripheral surface of the clutch housing 61 together with the inner peripheral surface of the clutch housing 61 . 8A shows the clutch 13 when the driven-side rotating body 65 is about to rotate counterclockwise when viewed in the axial direction X1 from the motor portion 11 side. Since the clutch housing 61 cannot rotate in the circumferential direction, the driven side rotating body 65 is prevented from rotating further by the clutch housing 61 and the rolling bodies 64 . As a result, the rotation of the worm shaft 52 is blocked, so that the rotation of the rotary shaft 24 from the worm shaft 52 side is suppressed. Note that the portion of the control surface 103 that contacts the rolling element 64 is a portion closer to the end of the control surface 103 in the circumferential direction than the center of the control surface 103 in the circumferential direction. FIG. 7(a) shows a case where the driven-side rotating body 65 attempts to rotate counterclockwise when viewed in the axial direction X1 from the motor section 11 side. If it were to attempt to rotate in a direction, it would likewise be prevented from doing so.

On the other hand, when the motor portion 11 is driven, that is, when the rotating shaft 24 rotates, the connecting member 62 is integrated with the rotating shaft 24 so as to move toward the central axis L1 of the rotating shaft 24, as shown in FIGS. 8(a) and 8(b). is driven to rotate around the center of rotation. 8(a), 8(b), 9(a) and 9(b), when viewed in the axial direction X1 from the motor portion 11 side, the rotating shaft 24 and the connecting member 62 are oriented counterclockwise. The clutch 13 is shown when it is driven to rotate. Then, the connecting member 62 is rotated with respect to the stopped support member 63, and each rolling element releasing portion 81 of the connecting member 62 is positioned on the front side of the rolling element releasing portion 81 in the rotational direction. to press the roller support 92 in the rotational direction. Then, the rolling elements held by the roller supports 92 are released from the clamping between the clutch housing 61 and the control surface 103 . Thereby, the lock of the driven side rotating body 65 is released. At this time, the driving-side transmission surface 75a of the connecting member 62 is not in contact with the first driven-side transmission surface 104 of the driven-side rotating body 65, and the driven-side rotating body 65 is maintained in a stopped state. . Also, the rolling elements 64 released from the clamping between the control surface 103 and the inner peripheral surface of the clutch housing 61 are restored to their original shapes by the paired roller supports 92 bringing the two outer peripheral side holding portions 95 closer to each other. Pushed back to the inner peripheral side. Each rolling element 64 is restrained from moving radially and circumferentially with respect to the support member 63 by the outer peripheral holding portion 95 and the inner peripheral holding portion 96 of the roller support 92 forming a pair.

Then, as shown in FIG. 9B, when the connecting member 62 is further rotationally driven by the rotating shaft 24, the drive-side transmission surface 75a comes into contact with the first driven-side transmission surface 104 in the rotational direction. That is, the drive-side transmission surface 75a of the connecting member 62 and the first driven-side transmission surface 104 of the driven-side insertion portion 102 are engaged in the rotational direction. As a result, the rotational driving force can be transmitted from the coupling member 62 to the driven-side insertion portion 102 via the drive-side transmission surface 75a and the first driven-side transmission surface 104, so that the driven-side rotating body 65 can move along with the coupling member 62. It rotates around the center axis of the driven side rotating body 65 . At this time, as shown in FIG. 9(a), since the support member 63 is pressed by the rolling element release portion 81 and rotates integrally with the connecting member 62, the rolling element 64 is also guided by the support member 63 to the driven side. It rotates together with the rotating body 65 . More specifically, the rolling elements 64 are arranged at the center of the control surface 103 in the circumferential direction while being held by the roller supports 92 . The rolling elements 64 are held by the support member 63 without being sandwiched between the inner peripheral surface of the clutch housing 61 and the control surface 103, and rotate about the center axis of the driven-side rotating body 65 together with the driven-side rotating body 65. Rotate around the center.

Here, as shown in FIG. 10A, in the motor 10, the rotating shaft 24 and the worm shaft 52 may be misaligned due to an assembly error or the like. FIG. 10(a) shows an example of a case in which the rotating shaft 24 and the worm shaft 52 are out of alignment. The figure shows a closed state. In addition, in FIG. 10A, the misalignment between the rotary shaft 24 and the worm shaft 52 is exaggerated for better understanding. In such a case, as shown in FIGS. 6, 9(b) and 10(a), the drive-side insertion portion 31 in the drive-shaft insertion hole 72 is positioned within the range of the drive-side allowable gap G1. 72, and the driven-side insertion portion 102 moves radially relative to the driven-shaft insertion hole 75 within the range of the driven-side allowable gap G2 in the driven-shaft insertion hole 75. Moving. As a result, axial misalignment between the rotating shaft 24 and the worm shaft 52 is allowed in the connecting member 62 . Therefore, it is possible to prevent a large radial load from being applied to the distal end portion of the rotary shaft 24 and the proximal end portion of the worm shaft 52 . At this time, the drive-side elastic member 74 is elastically deformed to allow radial relative movement of the drive-side insertion portion 31 with respect to the drive shaft insertion hole 72 . The annular elastic member 73 is also elastically deformable according to the relative movement of the drive-side insertion portion 31 with respect to the drive shaft insertion hole 72 in the radial direction. In addition, by allowing axial misalignment between the rotating shaft 24 and the worm shaft 52, the connecting member 62 is inclined with respect to the central axis L1 and the central axis L2.

FIG. 10(b) shows a state in which the rotary shaft 24 is rotated 90 degrees from the state shown in FIG. 10(a). 10(c) shows a state in which the rotating shaft 24 is further rotated by 90° from the state shown in FIG. 10(b). Moreover, FIG.10(d) has shown the state which rotated the rotating shaft 24 further 90 degrees from the state shown in FIG.10(c). When the rotary shaft 24 is further rotated by 90° from the state shown in FIG. 10(d), the state shown in FIG. 10(a) is restored. As shown in FIGS. 10(a) to 10(d), the connecting member 62 transmits the rotation of the rotating shaft 24 to the worm shaft 52 while allowing axial misalignment between the rotating shaft 24 and the worm shaft 52. do. Therefore, the rotating shaft 24 can rotate about the central axis L1 of the rotating shaft 24, and the worm shaft 52 can rotate about the central axis L2 of the worm shaft 52. Therefore, whirling of the distal end of the rotary shaft 24 and whirling of the proximal end of the worm shaft 52 are suppressed. For example, when the base end portion of the worm shaft 52 swings around, the base end portion of the worm shaft 52 repeatedly collides with the inner peripheral surface of the bearing 43 that supports the base end portion of the worm shaft 52, thereby generating noise. There is a risk. In contrast, in the present embodiment, since the base end portion of the worm shaft 52 is suppressed from whirling, the occurrence of abnormal noise during rotation of the rotary shaft 24 is suppressed.

As shown in FIG. 1 , when the worm shaft 52 rotates with the rotation of the driven rotor 65 , the rotation is decelerated by the worm shaft 52 and the worm wheel 53 and output from the output shaft 54 . 8(a), 8(b), 9(a) and 9(b), when the coupling member 62 is rotated counterclockwise when viewed in the axial direction X1 from the motor portion 11 side, Although the clutch 13 of FIG. However, in FIGS. 8(a), 8(b), 9(a) and 9(b), when the connecting member 62 is rotated clockwise, the drive-side transmission surface 75a is moved to the second driven It abuts on the side transmission surface 105 .

The operation of this embodiment will be described.
When the rotating shaft 24 rotates, the width across flat portion 32 abuts on the connecting plane portion 72c and engages in the rotational direction, so that the rotating shaft 24 and the connecting member 62 rotate integrally. A corner portion 32c of the boundary portion between the flat portion 32a and the curved surface portion 32b of the width across flat portion 32 is pressed against the connecting curved surface portion 72d of the width across flats hole portion 72a, but not against the connecting flat portion 72c. Therefore, the corner portion 32c is less likely to come into contact with the drive-side elastic member 74 provided on the connecting curved surface portion 72d.

Further, the drive-side elastic member 74 that presses the curved surface portion 32b radially inward has elasticity. Therefore, even if the connecting member 62 swings around, the whirling of the connecting member 62 is absorbed by the drive-side elastic member 74 . Therefore, the connection member 62 is prevented from swinging around greatly, so that the base end portion of the worm shaft 52 is prevented from swinging by the connection member 62 . Further, even if the tip of the rotating shaft 24 wobbles, the drive-side elastic member 74 absorbs the whirling of the tip of the rotating shaft 24, so that the connecting member 62 is prevented from whirling. Therefore, even in this case, the base end of the worm shaft 52 is prevented from being swung around by the connecting member 62 .

Effects of the present embodiment will be described.
(1) The drive-side elastic member 74 is provided at both circumferential ends of the connecting flat portion 72c where the corner 32c of the boundary portion between the flat portion 32a and the curved surface portion 32b is likely to be pressed when the rotating shaft 24 rotates. Not provided. The drive-side elastic member 74 is provided on the connecting curved surface portion 72d against which the corner portion 32c is less likely to be pressed when the rotating shaft 24 rotates. Therefore, when the rotating shaft 24 rotates, the corner portion 32c of the width across flat portion 32 is prevented from being pressed against the driving side elastic member 74, so that the driving side elastic member 74 is prevented from being torn. As a result, deterioration in durability of the drive-side elastic member 74 provided on the inner peripheral surface of the drive shaft insertion hole 72 can be suppressed.

(2) The drive-side elastic member 74 extends along the axial direction X1. Therefore, the frictional force between the curved surface portion 32b of the width across flat portion 32 and the drive-side elastic member 74 makes it easier to hold the connecting member 62 at the tip portion of the rotary shaft 24 . Therefore, assembly of the clutch 13 to the motor 10 becomes easier. In addition, whirling of the connecting member 62 is more easily absorbed by the drive-side elastic member 74 . Therefore, since the connecting member 62 is further suppressed from swinging around, it is possible to further suppress swinging of the base end portion of the worm shaft 52 by the connecting member 62 . Further, when the tip of the rotating shaft 24 whirles, the whirling of the tip of the rotating shaft 24 is more easily absorbed by the drive-side elastic member 74, so whirling of the connecting member 62 is further suppressed. . Therefore, in this case as well, the base end portion of the worm shaft 52 can be further suppressed from being swung around by the connecting member 62 . As a result, it is possible to further suppress the generation of abnormal noise when the rotary shaft 24 rotates. Further, the drive-side elastic member 74 can be easily formed.

(3) The drive-side elastic member 74 extends continuously from one end to the other end in the axial direction X1 in a range radially overlapping the width across flat portion 32 of the connecting curved surface portion 72d. Therefore, the frictional force between the curved surface portion 32b of the width across flat portion 32 and the drive-side elastic member 74 makes it easier to hold the connecting member 62 on the distal end portion of the rotary shaft 24 . Therefore, assembly of the clutch 13 to the motor 10 becomes easier. In addition, whirling of the connecting member 62 is more easily absorbed by the driving-side elastic member 74 . Therefore, since the connecting member 62 is further suppressed from swinging around, the base end portion of the worm shaft 52 can be further suppressed from swinging by the connecting member 62 . Further, when the tip portion of the rotating shaft 24 whirles, the whirling of the tip portion of the rotating shaft 24 is more easily absorbed by the drive-side elastic member 74, so whirling of the connecting member 62 is further suppressed. . Therefore, even in this case, it is possible to further prevent the base end of the worm shaft 52 from being swung around by the connecting member 62 . As a result, it is possible to further suppress the generation of abnormal noise during rotation of the rotary shaft 24 .

(4) An annular elastic member 73 that surrounds the outer periphery of the width across flats hole 72a as viewed from the axial direction X1 is provided at the axial end of the connecting member 62 on the side of the outer opening of the drive shaft insertion hole 72. is provided. The drive-side elastic member 74 is continuous with the annular elastic member 73 . Therefore, the annular elastic member 73 can prevent the drive-side elastic member 74 from being separated from the connecting curved surface portion 72d. For example, when the drive-side insertion portion 31 is inserted into the drive shaft insertion hole 72, even if the drive-side insertion portion 31 comes into contact with the drive-side elastic member 74 from the axial direction X1, the drive-side elastic member 74 is not an annular elastic member. By being supported by 73 , separation from the inner peripheral surface of drive shaft insertion hole 72 is suppressed.

(5) The drive-side allowable gap G1 is formed between the facing flat portion 32a and the connecting flat portion 72c, and between the facing curved surface portion 32b and the connecting curved surface portion 72d. Therefore, the drive-side insertion portion 31 can move relative to the drive shaft insertion hole 72 in both the direction parallel to the flat connection portion 72c and the direction orthogonal to the flat connection portion 72c. Therefore, the degree of freedom in the movement direction in the radial direction of the drive-side insertion portion 31 within the drive shaft insertion hole 72 is enhanced. Therefore, compared to the case where no driving-side allowable gap is provided between the facing flat portion 32a and the connecting flat portion 72c, the misalignment of the connecting member 62 in more directions with respect to the rotating shaft 24 and the Axial misalignment of the worm shaft 52 in more directions can be tolerated in the connecting member 62 .

(6) The driven side allowable gap G2 is formed between the connecting surface 75b and the outer peripheral surface of the driven side insertion portion 102 and between the drive side transmission surface 75a and the outer peripheral surface of the driven side insertion portion 102. Therefore, the driven-side insertion portion 102 is relatively movable with respect to the driven shaft insertion hole 75 in both the direction parallel to the drive-side transmission surface 75a and the direction orthogonal to the drive-side transmission surface 75a. In this way, since the connecting member 62 can allow axial misalignment between the rotating shaft 24 and the worm shaft 52 on both the rotating shaft 24 side and the worm shaft 52 side, It becomes possible to allow a larger axial misalignment. Therefore, when the rotating shaft 24 rotates, the radial load applied to the distal end portion of the rotating shaft 24, the connecting member 62, and the base end portion of the worm shaft 52 is further suppressed, thereby further suppressing noise generation. can.

This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.
- The connecting member 62 may have a second drive-side elastic member that has elasticity and presses the flat portion 32a radially inward.

The connecting member 62A shown in FIGS. 11 and 12 has a second drive-side elastic member 74A that has elasticity and presses the flat portion 32a of the width across flat portion 32 radially inward. In FIGS. 11 and 12, the same reference numerals are given to the same configurations and corresponding configurations as in the above embodiment. In the connecting member 62A, the driving side elastic member 74 provided on the connecting curved surface portion 72d is referred to as the first driving side elastic member 74. As shown in FIG. In each connecting plane portion 72c, the second drive-side elastic member 74A is located closer to the connecting plane than the portion exposed inside the drive shaft insertion hole 72 at both ends of the width across flats hole portion 72a in the longitudinal direction of the connecting plane portion 72c. It is provided in a portion near the center in the longitudinal direction of the width across flats hole portion 72a in the portion 72c. That is, in each connecting plane portion 72c, the second drive-side elastic member 74A is positioned more in the circumferential direction of the connecting plane portion 72c than the portion exposed inside the drive shaft insertion hole 72 at both ends of the connecting plane portion 72c in the circumferential direction. is located near the center of the In this specification, "both ends of the connecting flat portion in the circumferential direction are exposed to the inside of the drive shaft insertion hole" means that from the circumferential end of the connecting flat portion toward the center of the connecting flat portion in the circumferential direction. means that a range having a width in the circumferential direction of is exposed inside the drive shaft insertion hole. In this example, the second driving-side elastic member 74A is provided at the center portion in the circumferential direction of the connecting plane portion 72c. Then, the portions on both sides in the circumferential direction of the second driving-side elastic member 74A in the connection flat portion 72c form exposed portions 72g exposed inside the drive shaft insertion hole 72. As shown in FIG. That is, the second drive-side elastic member 74A is provided between the exposed portions 72g provided at both ends in the circumferential direction of the connecting flat portion 72c. The second drive-side elastic member 74A forms a ridge extending continuously from one axial end to the other axial end of the connecting plane portion 72c along the axial direction X1. The second drive-side elastic member 74A protrudes radially inward from the connection plane portion 72c on which the second drive-side elastic member 74A is provided. When the drive-side insertion portion 31 is not inserted into the drive shaft insertion hole 72, the distance between one second drive-side elastic member 74A and the other second drive-side elastic member 74A is the width across flats portion. Narrower than the width of 32 in the transverse direction. Therefore, when the drive-side insertion portion 31 is inserted into the drive shaft insertion hole 72, each second drive-side elastic member 74A presses the flat portion 32a of the width across flat portion 32 radially inward. 12 illustrates the connecting member 62A in a state in which the drive-side insertion portion 31 is not inserted into the drive shaft insertion hole 72, and also illustrates the drive-side insertion portion 31 with a two-dot chain line.

In this way, the second driving-side elastic member 74A is arranged in the circumferential direction of the connecting flat portion 72c, which is likely to be pressed against the corner portion 32c of the boundary portion between the flat portion 32a and the curved surface portion 32b when the rotating shaft 24 rotates. It is not provided at both ends. Further, the second driving-side elastic member 74A has a lower possibility of pressing the corner portion 32c when the rotating shaft 24 rotates, and the connecting flat portion 72c is more likely to be pressed than the exposed portions 72g at both ends in the circumferential direction of the connecting flat portion 72c. It is provided in a portion near the center in the circumferential direction. Therefore, when the rotating shaft 24 rotates, the corner portion 32c of the boundary portion between the flat portion 32a and the curved surface portion 32b is suppressed from being pressed against the second drive side elastic member 74A. Occurrence of rupture or the like is suppressed. As a result, deterioration in durability of the second drive-side elastic member 74A provided on the inner peripheral surface of the drive shaft insertion hole 72 can be suppressed.

Further, the frictional force between the flat portion 32a of the width across flat portion 32 and the second drive-side elastic member 74A makes it easier to hold the connecting member 62A on the distal end portion of the rotary shaft 24. As shown in FIG. Accordingly, assembly of the clutch to the motor 10 becomes easier. In addition, whirling of the connecting member 62A is also absorbed by the second drive-side elastic member 74A. Therefore, the connecting member 62A is further prevented from swinging around, so that the base end portion of the worm shaft 52 can be further prevented from swinging by the connecting member 62A. Further, when the tip portion of the rotating shaft 24 whirles, the whirling of the tip portion of the rotating shaft 24 is also absorbed by the second drive-side elastic member 74A, so whirling of the connecting member 62A is further suppressed. be. Therefore, even in this case, it is possible to further suppress the base end portion of the worm shaft 52 from being swung around by the connecting member 62A. As a result, it is possible to further suppress the generation of abnormal noise during rotation of the rotating shaft 24 .

In the above embodiment, the drive-side elastic member 74 is continuous with the annular elastic member 73 . However, the drive-side elastic member 74 does not necessarily have to be continuous with the annular elastic member 73 .
- The shape of the annular elastic member 73 is not limited to that of the above embodiment. The annular elastic member 73 is provided at the end of the connecting member 62 in the axial direction X1, which is the end on the outer opening side of the drive shaft insertion hole 72. Any shape may be used as long as it forms an annular shape surrounding the outer periphery. For example, the annular elastic member 73 may be configured without the pressing portion 73a. Further, for example, the annular elastic member 73 may be provided on the end surface of the connecting member 62 on the side of the outer opening of the drive shaft insertion hole 72 in the axial direction X1. Also, the connecting member 62 does not necessarily have to include the annular elastic member 73 .

- In the above-described embodiment, one drive-side elastic member 74 is provided at the center of each connecting curved surface portion 72d in the circumferential direction. The drive-side elastic member 74 does not necessarily have to be provided in the circumferential central portion of the connecting curved surface portion 72d. For example, the drive-side elastic member 74 may be provided at a position shifted in the circumferential direction from the center of the connecting curved surface portion 72d in the circumferential direction. In this case, the drive-side elastic member 74 provided on one connecting curved surface portion 72d and the driving-side elastic member 74 provided on the other connecting curved surface portion 72d may be provided at intervals of 180° in the circumferential direction. preferable. Further, a plurality of drive-side elastic members 74 may be provided on at least one connecting curved surface portion 72d.

As long as the drive-side elastic member 74 is provided on the connecting curved surface portion 72d, the shape and formation range are not limited to those of the above embodiment. For example, the drive-side elastic member 74 extends continuously from one end to the other end of a range in which the connecting curved surface portion 72d overlaps the width across flat portion 32 in the radial direction, and further extends continuously to the outside of the range. There may be. Further, for example, the drive-side elastic member 74 may be provided in a part of the range radially overlapping the width across flat portion 32 in the connecting curved surface portion 72d. Further, for example, the drive-side elastic member 74 may extend along a direction inclined with respect to the axial direction X1.

- The drive shaft insertion hole 72 may not be provided with the enlarged diameter portion 72b. For example, the drive shaft insertion hole 72 may be composed only of the width across flats hole portion 72a.
- In the above embodiment, the drive shaft insertion hole 72 and the driven shaft insertion hole 75 communicate with each other. However, the drive shaft insertion hole 72 and the driven shaft insertion hole 75 may be separated in the axial direction X1.

- The positional relationship in the rotational direction between the drive shaft insertion hole 72 and the driven shaft insertion hole 75 is not limited to the positional relationship in the above embodiment. For example, the driven shaft insertion hole 75 may be formed so that the direction orthogonal to the drive-side transmission surface 75a is the same as the direction orthogonal to the connecting plane portion 72c.

- The first driven-side elastic member 76 and the second driven-side elastic member 77 do not necessarily have to be provided on the inner peripheral surface of the driven shaft insertion hole 75 .
If the clutch 13 is provided with a connecting member 62 having a drive shaft insertion hole 72 and a driven shaft insertion hole 75 provided with a drive-side elastic member 74 on the inner peripheral surface, the rest of the configuration is the same as that of the above embodiment. Not exclusively.

In the above embodiment, the driven-side insertion portion 102 has a substantially elliptical cross-sectional shape perpendicular to the axial direction of the worm shaft 52 . However, the shape of the driven-side insertion portion 102 is not limited to this. The driven-side insertion portion 102 has a cross-sectional shape orthogonal to the axial direction of the worm shaft 52 having a lateral direction and a longitudinal direction so that it can be engaged with the inner peripheral surface of the driven shaft insertion hole 75 in the rotational direction. I wish I had.

- The drive-side insertion portion 31 may be formed separately from the rotary shaft 24 and fixed to the distal end portion of the rotary shaft 24 so as to be integrally rotatable. The driven-side insertion portion 102 may be formed separately from the worm shaft 52 and fixed to the base end portion of the worm shaft 52 so as to be rotatable therewith.

The configuration of the speed reduction mechanism 51 is not limited to that of the above embodiment as long as it includes the worm shaft 52 . For example, the speed reduction mechanism 51 may be configured with a plurality of speed reduction gears to which the rotation of the worm shaft 52 is transmitted.

Technical ideas that can be grasped from the above embodiment and modifications will be described.
(a) The connecting member includes a second driving-side elastic member that has elasticity and presses the flat portion radially inward, and the second driving-side elastic member is provided at both ends of the connecting flat portion in the circumferential direction. A motor provided in a portion closer to the center in the circumferential direction of the connection flat portion than the portion exposed to the inside of the drive shaft insertion hole.

DESCRIPTION OF SYMBOLS 10... Motor 13... Clutch 24... Rotating shaft 31... Drive-side insertion part 32... Width-flat part 32a... Flat part 32b... Curved surface part 51... Reduction mechanism 52... Worm shaft 62, 62A Connection member 72 Drive shaft insertion hole 72a Width across flats hole 72c Connection plane portion 72d Connection curved surface portion 73 Annular elastic member 74 Driving side elastic member 75 Driven shaft insertion hole , 102... driven side insertion portion, G1... driving side allowable gap, X1... axial direction.

Claims (4)

a rotated axis of rotation (24);
a reduction mechanism (51) including a worm shaft (52) arranged coaxially with the rotating shaft;
a clutch (13) having connecting members (62, 62A) that connect the rotating shaft and the worm shaft so as to be rotatable together;
The rotating shaft has a drive-side insertion portion (31) at the distal end of the rotating shaft,
The worm shaft has a driven side insertion portion (102) at the base end of the worm shaft,
The connecting member includes a drive shaft insertion hole (72) having an inner peripheral surface into which the drive side insertion portion is inserted and into which the drive side insertion portion is engaged in the rotational direction; a driven shaft insertion hole (75) having an inner peripheral surface with which the insertion portion engages in the rotational direction;
The drive-side insertion portion has a two-sided width shape having an outer peripheral surface having a pair of flat portions (32a) parallel to each other and a pair of curved surface portions (32b) located between the pair of flat portions (32b). having a width portion (32),
The drive shaft insertion hole has two inner peripheral surfaces having a pair of connecting plane portions (72c) parallel to each other and a pair of connecting curved surface portions (72d) located between the pair of connecting plane portions. having a width across flats hole (72a) into which the width across flats portion is inserted,
Radial movement of the drive-side insertion portion within the drive shaft insertion hole is controlled between the opposing flat portion and the connecting flat portion and between the opposing curved surface portion and the connecting curved surface portion. Provided with an allowable driving side allowable gap (G1),
A drive-side elastic member (74) having elasticity and pressing the curved surface portion radially inward is provided on the connecting curved surface portion,
A motor in which both circumferential ends of the connection flat portion are exposed inside the drive shaft insertion hole. 2. The motor according to claim 1, wherein the drive-side elastic member extends along the axial direction (X1) of the rotating shaft. 3. The motor according to claim 2, wherein the drive-side elastic member extends continuously from one end to the other end in the axial direction in at least a range radially overlapping the width across flat portion of the connecting curved surface portion. The connecting member is provided at an end of the connecting member in the axial direction of the rotating shaft and on the side of the outer opening of the drive shaft insertion hole. having an annular elastic member (73) that surrounds the
4. The motor according to any one of claims 1 to 3, wherein the drive-side elastic member is continuous with the annular elastic member.

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