Clutch, motor and method for producing a clutch

Abstract

Coupling (40) with: an annular coupling housing (41); a drive-side rotating body (42) constructed to be driven to rotate; a driven-side rotary body (45) to which the rotary drive force is transmitted from the drive-side rotary body (42); a rolling element (44) arranged between an inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45), wherein, when the driving-side rotating body (42) is driven for rotation, the rolling element (44) rotates together with the driving-side rotating body (42) about a rotation axis of the driving-side rotating body (42), and when the driving-side rotating body (42) is not driven for rotation, the rolling element (44) is held between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and inhibits rotation of the driven-side rotating body (45); a support member (43), wherein, when inserted into and fixed to the clutch housing (41) from a distal side, the support member (43) holds the rolling element (44) between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and rotates together with the driving-side rotating body (42) about the rotation axis of the driving-side rotating body (42); and Grease (GR) located between the inner peripheral surface (41c) of the clutch housing (41) and the rolling element (44), wherein the support element (43) has a guide (66a) arranged on a distal surface of the support element (43), the guide (66a) has an inclined portion (66a) which is inclined toward a base side from an axial center to a radially outer side, and the guide (66a) is constructed such that, when the grease (GR) is unevenly applied to the inner peripheral surface (41c) of the clutch housing (41), it guides the grease (GR) such that it is evenly applied to the inner peripheral surface (41c) of the clutch housing (41) when introduced into the clutch housing (41).

Description

Technical area

[0001] The present invention relates to a clutch, a motor and a method for manufacturing a clutch. Background of the state of the art

[0002] A typical motor (electric motor) used as a drive source of an on-board power window device or the like includes a motor unit and an output unit (power output unit). The motor unit includes a rotating shaft configured to be driven for rotation. The output unit includes a driven shaft configured to receive rotational drive force from the rotating shaft and output the rotational drive force received by the driven shaft. The rotating shaft and the driven shaft are coupled by a clutch that operates to prevent rotational drive force from the driven shaft from being transmitted to the rotating shaft while transmitting rotational drive force from the rotating shaft to the driven shaft (see, for example, Patent Document 1).

[0003] Such a coupling includes a drive-side rotating body that rotates integrally with the rotating shaft, a driven-side rotating body that is engageable with the drive-side rotating body in one rotational direction and rotates integrally with the driven shaft, and a tubular coupling case into which the drive-side rotating body and the driven-side rotating body are inserted. Furthermore, a rolling element is interposed between the inner peripheral surface of the coupling case and the driven-side rotating body. When the rotating shaft is not driven to rotate, the rolling element (used as a key) is held by the inner peripheral surface of the coupling case and the driven-side rotating body, thereby restraining (preventing) the rotation of the driven-side rotating body (i.e., the rotation of the driven shaft).The rolling element is supported by a support member inserted into the clutch housing so that the center axis of the rolling element extends parallel to the rotation axis of the drive-side rotating body (drive-side rotating body). When the rotating shaft is driven to rotate, the support member rotates together with the drive-side rotating body around the rotation axis of the drive-side rotating body. When the rotating shaft is driven to rotate, the rolling element rotates together with the drive-side rotating body and the driven-side rotating body around the rotation axis of the drive-side rotating body along the inner peripheral surface of the clutch housing while supported by the support member. The clutch further has grease interposed between the inner peripheral surface of the clutch housing and the rolling element to achieve an appropriate frictional force. State of the art documentsPatent document Patent Document 1: Japanese Patent Application Laid-Open No. JP 2017-17952 A Patent document 2: DE 11 2017 004 972 T5

[0004] DE 11 2017 004 972 T5 discloses a clutch comprising: an annular clutch housing; a drive-side rotating body that is rotationally driven; a driven-side rotating body to which a rotational driving force is transmitted from the drive-side rotating body, wherein the driven-side rotating body has a portion disposed inside the clutch housing; a roller disposed between an inner peripheral surface of the clutch housing and the driven-side rotating body, wherein the roller is rotated about a rotational axis of the drive-side rotating body together with the drive-side rotating body when the drive-side rotating body is rotationally driven, wherein the roller hinders rotation of the driven-side rotating body by being sandwiched between the inner peripheral surface of the clutch housing and the driven-side rotating body when the drive-side rotating body is not rotationally driven;a support member sandwiching the roller between the inner peripheral surface of the clutch housing and the driven-side rotating body, the support member rotating around the rotational axis of the drive-side rotating body together with the drive-side rotating body; and a grease disposed at least between the inner peripheral surface of the clutch housing and the roller, the support member restricting rotation of the roller around a central axis of the roller. Summary of the invention

[0005] For example, in the clutch described above in JP 2017-17952 A, the grease can be injected collectively into a large space of the clutch housing (injected as a whole), and each element can be rotated so that the grease is evenly applied to the inner peripheral surface of the clutch housing. However, this can adversely affect the initial properties of such a clutch. For example, the grease can harden and act as a resistance in an initial state.

[0006] It is an object of the present invention to provide a clutch, a motor and a method for manufacturing a clutch which improve the initial properties.

[0007] This object is achieved by the subject matter of patent claims 1, 2, 4 and 5 as well as by the methods according to claims 3 and 6.

[0008] In this design, the distal surface of the support member has a guide configured to guide the grease unevenly applied to the inner peripheral surface of the clutch member. When inserted into the clutch housing, the grease is evenly applied to the inner peripheral surface of the clutch housing. As a result, when the support member is coupled to the clutch housing, the grease is applied approximately evenly. This improves the initial (starting) characteristics of the clutch. A motor with the clutch is shown in claim 2. An alternative clutch is set forth in claim 4. An engine having the alternative clutch is set forth in claim 5.

[0009] A method for manufacturing a clutch is set forth in claim 3. This method includes the step of applying grease to the base side of the inner peripheral surface of the clutch housing and the step of inserting the support member into the clutch housing, thereby distributing the grease to the distal side of the inner peripheral surface of the clutch housing. As a result, when the support member is coupled to the clutch housing, the grease is applied approximately evenly. This improves the initial characteristics (starting characteristics) of the clutch.

[0010] An alternative method for producing a coupling is shown in claim 6. Brief description of the drawings

[0011] The above-mentioned objects and other objects of the present invention and aspects and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings. Fig. 1 shows a cross-sectional view of an embodiment of a motor. Fig. 2 shows a partial enlarged cross-sectional view of the engine of the embodiment. Fig. 3 shows an exploded perspective view of an embodiment of a coupling. Fig. 4A shows a side view of a support member that holds a rolling element in the clutch of the embodiment, and Fig. 4 shows a bottom view of the support element. Fig. Fig. 5 shows a partial enlarged cross-sectional view of the coupling of the embodiment (a cross-sectional view taken along a line 6a-6a in Fig. 2). Fig. Fig. 6 A shows a cross-sectional view of the coupling of the embodiment (a cross-sectional view taken along a line 6a-6a in Fig. 2), and Fig. Figure 6B shows a cross-sectional view of the coupling (cross-sectional view along a line 6a-6a in Fig. 2). The Fig. 7A, Fig. 7B and Fig. 7C show partial schematic cross-sectional views of a method for manufacturing a coupling. The Fig. 8A and Fig. 8B show cross-sectional views of operations in the clutch of the embodiment. The Fig. 9A and Fig. 9B show cross-sectional views of operations of the clutch of the embodiment. The Fig. 10A and Fig. 10B show cross-sectional views of operations of the clutch of the embodiment. Fig. 11 shows a partial schematic cross-sectional view of another example of a coupling. Fig. 12 shows a partial schematic cross-sectional view of another example of a coupling. Modes for carrying out the invention

[0012] An embodiment of a motor with a clutch is described below.

[0013] Fig. 1 shows the present embodiment of a motor (electric motor) 10 included in a power window device that electrically raises and lowers a window pane (window glass) of a vehicle. The motor (electric motor) 10 includes a motor unit 20 and an output unit (power output unit) 30 that are integrally coupled to each other. The motor unit 20 generates rotational force. The output unit 30 reduces the speed output by the motor unit 20 and outputs the rotation. The motor 10 further includes a clutch 40 disposed in a drive coupling portion between the motor unit 20 and the output unit 30.

[0014] The motor unit 20 of the present embodiment is formed of a DC motor. The motor unit 20 includes a tubular yoke housing 21 (hereinafter referred to as yoke 21) having a closed end and an inner peripheral surface to which magnets 22 are fixed. An armature 23 is arranged on an inner side of the magnets 22. The armature 23 has a rotating shaft 24 arranged at a central portion of the yoke 21. The rotating shaft 24 has a base end (upper end in Fig. 1), which is rotatably supported by a bearing 25 arranged at the center of the closed end of the yoke 21. A tubular commutator (current transformer) 26 is fixed to the rotary shaft 24 at a portion near a distal end of the rotary shaft 24. The distal end (lower end in Fig. 1) the rotary shaft 24 has a coupling portion 24a with two parallel flat portions obtained by cutting a cylindrical rod in parallel.

[0015] A flange 21a extends outward from the opening of the yoke 21. A brush holder 27 is fitted at the opening of the yoke 21. The brush holder 27 has a holder body 27a shaped to close the opening of the yoke 21, and a connecting portion 27b projecting from the holder body 27a to a radially outer side of the yoke 21 and connected to an external connecting member not shown in the drawings. The holder body 27a holds power supply brushes (brushes for supplying electric power) 28 electrically connected to the connecting portion 27b by wires not shown in the drawings. The power supply brushes 28 slide on the commutator 26. The holder body 27a also holds a bearing 29 at a central portion of the holder body 27a. The bearing 29 rotatably supports a portion of the rotary shaft 24 disposed between the commutator 26 and the coupling portion 24a.The armature 23 (rotation shaft 24) is constructed to be driven to rotate, that is, the motor unit 20 is driven to rotate when external electric power supplied to the brushes 28 through the connecting portion 27b is supplied to the armature 23 through the commutator 26.

[0016] The output unit 30 is designed to accommodate a speed reduction mechanism 32 and the like in a plastic gear case 31. A portion (upper end in Fig. 1) The gear housing 31, which faces the motor housing 20 in the axial direction, has a fixing portion 31a that fixes the gear housing 31 to the motor unit 20. The outer shape of the fixing portion 31a is identical to the outer shape of the flange 21a of the yoke 21. The fixing portion 31a has a housing recess 31b open to the inside of the yoke 21. When the holder body 27a of the brush holder 27 is partially inserted into the housing recess 31b, the flange 21a comes into contact with the fixing portion 31a and is fixed to the fixing portion 31a by a screw 33. As a result, the yoke 21 is fixed to the gear housing 31, and the motor unit 20 is integral with the output unit 30. The brush holder 27 is held between the yoke 21 and the fixing portion 31a.

[0017] The transmission case 31 includes a clutch housing 31c recessed from the center of the bottom of the accommodation recess 31b in the axial direction, and a worm shaft housing (worm shaft holder) 31d extending from the center of the bottom of the clutch housing 31c in a direction extending along a center axis L1 of the rotary shaft 24. The transmission case 31 further includes a gear housing 31e extending from one side (right side in Fig. 1) of the worm shaft housing 31d. The gear housing 31e is connected to the worm shaft housing 31d at a central portion of the worm shaft housing 31d in the axial direction (longitudinal direction).

[0018] The worm shaft housing 31d houses a worm shaft 34 used as a driven shaft in the form of a cylindrical rod. The worm shaft 34 is formed of a metal material, and an axially central portion of the worm shaft 34 includes a worm portion 34a with threaded teeth. Two bearings 35 and 36 are arranged at axially opposite ends of the worm shaft housing 31d to rotationally support axially opposite ends of the worm shaft. When the worm shaft is arranged in the worm shaft housing 31d and rotationally supported by the bearings 35 and 36, the worm shaft 34 is coaxial with the rotating shaft 24, that is, the central axis L1 of the rotating shaft 24 is aligned with a central axis L2 of the worm shaft 34.

[0019] In the wheel housing 31e, a discoid worm wheel 37 is rotatably housed, which is engaged with the worm shaft 34a of the worm shaft 34. The speed reduction mechanism (rotational speed reduction mechanism) 32 includes the worm wheel 37 and the worm shaft 34. More specifically, the speed reduction mechanism 32 of the present embodiment is a worm speed reduction mechanism (i.e., a worm gear). An output shaft 38 extends in a radially central portion of the worm wheel 37 in the axial direction of the worm wheel 37 (a direction perpendicular to the plane of the drawing of Fig. 4) and rotates integrally with the worm gear 37. The output shaft 38 is coupled to a vehicle window glass through a window regulator not shown in the drawings.

[0020] The coupling 40, which couples the rotary shaft 24 of the motor unit 20 to the worm shaft 34 of the delivery unit 30, is housed in the coupling container 31c.

[0021] As this is the case in the Fig. 2 and Fig. 3, the clutch 40 includes a ring-like clutch housing 41, a drive-side rotating body 42 (drive-side rotating body), a support member 43, rolling elements 44, and a driven-side rotating body 45.

[0022] The clutch housing 41 is tubular. A flange-shaped mounting flange 41a extends radially outward from an axial base end of the clutch housing 41. The outer diameter of the tubular portion of the clutch housing 41 is substantially the same as the inner diameter of the clutch housing 31c. The outer diameter of the mounting flange 41a is larger than the inner diameter of the clutch housing 31c. The mounting flange 41a has mounting recesses 41b at four positions spaced at equal angles in the circumferential direction. Each of the mounting recesses 41b extends through the mounting flange 41a in the axial direction and is open radially outward.

[0023] As this is Fig. As shown in Fig. 2, the clutch housing 41 is inserted into the clutch case 31c from the distal side until the fastening flange 41a comes into contact with the bottom surface of the accommodation recess 31b, and is fixed to the gear case 31 at the fastening flange 41a. Specifically, fastening projections 31f protrude in the axial direction from the bottom surface of the accommodation recess 31b around the opening of the clutch case 31c at four positions spaced at equal angles in the circumferential direction. The four fastening fastening projections 31f are inserted into the four fastening recesses 41b of the fastening flange 41a in the axial direction. The distal end of each fastening projection 31f is thermally swaged. As a result, the clutch housing 41 is fixed to the transmission case 31 so that the clutch housing 41 cannot move in the axial direction and cannot rotate in the circumferential direction.The clutch housing 41, which is fixed to the gear housing 31, is coaxial with the rotary shaft 24 and the worm shaft 34.

[0024] The drive-side rotating body 42 has a tubular shaft coupling portion 51. The shaft coupling portion 51 is integrally formed with a discoid flange 52 extending radially outward from the outer peripheral surface of the shaft coupling portion 51.

[0025] A drive shaft insertion hole 53 extends axially in an axial center of the axial end (upper end in Fig. 2) The shaft coupling portion 51, which is arranged toward the motor unit 20. The drive shaft insertion hole 53 is defined by two parallel flat portions corresponding to the outer shape of the coupling portion 24a of the rotary shaft 24. The shape of the two parallel flat portions refers to a shape of an object with a cross-section that has at least straight lines parallel to each other. In one example, two parallel straight lines of a cross-section in two parallel flat portions are connected to each other by curved (arc-shaped) curves. When the coupling portion 24a is press-fitted into the drive shaft insertion hole 53, the drive-side rotating body 42 is coupled to the rotary shaft 24 so as to rotate integrally with the rotary shaft 24. The rotary shaft 24 is coaxial with the drive-side rotating body 42, which is coupled to the rotary shaft 24 (i.e., the central axes are aligned with each other).

[0026] In addition, a driven shaft insertion hole 54 extends in an axial center of the axial end (lower end in Fig. 2) the shaft coupling portion 51, which is located toward the output unit 30 (on the output unit 30 side). The center axis of the driven shaft insertion hole 54 coincides with the center axis of the drive shaft insertion hole (drive shaft insertion hole) 53. In the present embodiment, the drive shaft insertion hole 53 is continuous with the driven shaft insertion hole 54.

[0027] As this is Fig. As shown in Fig. 6B, the wall surface of the driven shaft insertion hole 54 includes two drive-side transmission surfaces 54a that are flat and parallel to the axial direction and to each other. When viewed in the axial direction, the driven shaft insertion hole 54 has a shape of a sports field racetrack (two parallel flat sections) such that the long side direction coincides with a direction parallel to the drive-side transmission surfaces 54a, and the short side direction coincides with a direction perpendicular to the drive-side transmission surfaces 54a. Each drive-side transmission surface 54a is provided with two first elastic members 55 formed of an elastic material such as a rubber material.From an axial perspective, the opposite longitudinal ends of the driven shaft insertion hole 54 are each provided with a second elastic member 56 formed of an elastic material such as a rubber material. The first and second elastic members 55 and 56 protrude slightly inward from the wall surface of the driven shaft insertion hole 54.

[0028] As this is the case in the Fig. 3 and Fig. 6A, the drive-side rotating body 42 has two rolling element release devices 57 extending from the flange 52 to the output unit 30 (in Fig. 3 downward) in the axial direction. When viewed axially, the rolling element release devices 57 are arranged on opposite sides of the driven shaft insertion hole 54 in the longitudinal direction. The two rolling element release devices 57 are arranged at positions separated (spaced) by 180° in a rotational direction and opposite to each other in a radial direction. Opposite circumferential ends of each rolling element release device 57 include elastic portions 58 formed of an elastic material such as a rubber material. The rolling element release devices 57 are arranged on an inner side of the clutch housing 41.

[0029] As this is the case in the Fig. 2 and Fig. As shown in Figure 3, the support member 43 is configured to hold the rolling elements 44 between an inner peripheral surface 41c of the clutch housing 41 and the driven-side rotating body 45, which are opposite to each other in a radial direction. The support member 43 of the present embodiment is formed of plastic.

[0030] The support member 43 has a ring 61 arranged on a base side and annular around the center axis L2 of the worm shaft 34. The outer diameter of the ring 61 is larger than the inner diameter of the clutch housing 41. The ring 61 is arranged closer to the motor unit 20 than the mounting flange 41a of the clutch housing 41 (upper side in Fig. 2) and is opposite to the mounting flange 41a in the axial direction. The ring 61 has a lower surface (axial end surface opposite to the mounting flange 41a) including a lower projection 61a in the shape of an annular projection extending in the circumferential direction of the ring 61 and in contact with the mounting flange 41a in the axial direction. The ring 61 has an upper surface (upper surface facing the drive-side rotating body 42) including an upper projection 61b protruding in the axial direction and in contact with the flange 52 of the drive-side rotating body 42 in the axial direction.

[0031] Rolling element holders 62 are arranged at two positions spaced apart from each other in the circumferential direction (in the present embodiment, two positions spaced apart by 180°) on a circumferential inner side of the ring 61. The rolling element holders 62 are in the shape of a rod extending in the axial direction and hold the respective rolling elements 44.

[0032] As this is the case in the Fig. 4A and Fig. 4B, each rolling element 44 is formed of plastic and has a central axis L3 extending parallel to the central axis L1 of the rotary shaft 24 and the central axis L2 of the worm shaft 34. In the present embodiment, each rolling element 44 has two parallel flat portions when viewed in the axial direction. Thus, when viewed in the axial direction, the shape of the rolling element 44 has a long side direction and a short side direction. In the Fig. In the state shown in FIG. 4B, the radial direction of the clutch 40 coincides with the long side direction of the rolling element 44, and the circumferential direction of the clutch 40 coincides with the short side direction of the rolling element 44. Each rolling element 44 has first and second opposing surfaces (opposing surfaces) 71a and 71b that are flat and located on opposite sides in a rotation direction X1 of the drive-side rotating body 42 (in accordance with the circumferential direction of the clutch 40, hereinafter referred to as the rotation direction X1). The rolling element 44 further has first and second arcuate (curved) surfaces 72a and 72b located on opposite sides of the clutch 40 in the radial direction. In the present embodiment, the circumferential surface of the rolling element 44 includes the first and second opposing surfaces 71a and 71b and the first and second arcuate surfaces 72a and 72b.

[0033] As this is Fig. 5, in each rolling element 44, the first and second opposed surfaces 71a and 71b are parallel to the central axis L3 and to each other. In the rolling element 44, the first and second arcuate (curved) surfaces 72a and 72b have the shape of an arc whose center of curvature is the central axis L3 when viewed in the axial direction. In the present embodiment, the first and second arcuate surfaces 72a and 72b have the same curvature. The first and second arcuate surfaces 72a and 72b are not inclined and are parallel to the central axis L3. In the rolling element 44, the first arcuate surface 72a is arranged radially outward and opposes the tubular inner peripheral surface 41c of the clutch housing 41 in the radial direction and is contactable with the inner peripheral surface 41c.In the rolling element 54, the second arcuate surface 72b is arranged radially inward and faces the driven-side rotating body 45 in the radial direction and is contactable with the driven-side rotating body 45. The axially opposite end surfaces of the rolling element 44 are flat and perpendicular to the first and second opposing surfaces 71a and 71b (see FIG. Fig. 4A).

[0034] As this is the case in the Fig. 3, Fig. 4A and Fig. 4B, each rolling element support device 62 has an axial support portion 63 extending radially inward from the ring 61. The axial support portion 63 faces the rolling element 44 in the axial direction. The rolling element support device 62 further has two roller supports 64a and 64b extending from circumferentially opposite ends of the axial support portion 63 away from the ring 61 (downward in Fig. 4A) in the axial direction (direction of the center axes L1 and L2). In the rolling element holding device 62, the paired roller supports 64a and 64b are arranged on opposite sides of the rolling element 44 in the rotational direction X1 and support the rolling element 44 from the opposite sides in the rotational direction X1 such that the center axis L3 extends parallel to the center axis L1. When the coupling 40 is viewed from the motor unit 20 in the axial direction (ie, the direction shown in Fig. 6A), among the roller supports 64a and 64b provided as a pair in the rolling element holding device 62, the one roller support located on the counterclockwise side of the rolling element 44 is referred to as a first roller support 64a, and the one roller support located on the clockwise side of the rolling element 44 is referred to as a second roller support 64b.

[0035] The support member 43 further includes coupling portions 66, each of which couples the distal end of the first roller support 64a of one rolling element support 62 to the distal end of the second roller support 64b of the other rolling element support 62. The coupling portions 66 are arcuate (curved) about the central axes L1 and L2 when viewed axially. The distal end of each of the roller supports 64a and 64b has a retaining hook 67 projecting between the first and second roller supports 64a and 64b, which are provided as a pair. Each retaining hook 67 contacts an axial end surface of the rolling element 44 to prevent the rolling element 44 from detaching (separating) from the rolling element support 62 in the axial direction.

[0036] As this is the case in the Fig. 4B and Fig. 5, in each rolling element support device 62, the pair of roller supports 64a and 64b have side surfaces opposite to each other in the rotational direction X1, including first and second contact surfaces 68a and 68b, respectively. The first contact surface 68a of the first roller support 64a is flat and parallel to the central axes L1 and L2 and faces the first opposing surface 71a of the rolling element 44 arranged between the pair of roller supports 64a and 64b. In the same manner as the first contact surface 68a, the second contact surface 68b of the second roller support 64b is flat and parallel to the central axes L1 and L2 and faces the second opposing surface 71b of the rolling element 44 arranged between the pair of roller supports 64a and 64b.

[0037] The first and second opposing surfaces 71a and 71b, which are opposite in the rotational direction X1, are parallel to each other. The first and second contact surfaces 68a and 68b are longer in the axial direction than the rolling element 44 (first and second opposing surfaces 71a and 71b). The radial width of the clutch 40 at the first and second contact surfaces 68a and 68b is greater than or equal to the radial width of the clutch 40 at the first and second opposing surfaces 71a and 71b.

[0038] The rolling element 44 has a maximum diameter D1 (i.e., a longitudinal dimension or dimension in the longitudinal direction of the rolling element 44 when viewed axially) that is greater than a distance D2 between the first contact surface 68a and the second contact surface 68b of the rolling element support 62. The distance D2 of the rolling element support 62 is greater than a dimension D3 of the rolling element 44 in the rotational direction X1 (in the present embodiment, it is the distance between the first opposing surface 71a and the second opposing surface 71b, or the dimension of the rolling elements 44 in the short-side direction when viewed axially). Therefore, the pair of roller supports 64a and 64b are spaced from the rolling element 44 arranged between the roller supports 64a and 64b by a tolerance gap G1 that determines a range within which the rolling element 44 rotates about the central axis L3.Thus, the rotation of the rolling element 44 about the central axis L3 is limited by the roller supports 64a and 64b provided as a pair.

[0039] As this is Fig. As shown in Fig. 5, when viewed from the motor unit 20 in the axial direction, when the rolling element 44 is rotated counterclockwise about the center axis L3 between the pair of roller supports 64a and 64b, the rolling element 44 contacts the first contact surface 68a via the end of the first opposing surface 71a located toward the first arcuate surface 72a, as shown by one-dot chain lines. Furthermore, the rolling element 44 contacts the second contact surface 68b via the end of the second opposing surface 71b located toward the second arcuate surface 72b.When viewed from the motor unit 20 in the axial direction, when the rolling element 44 is rotated clockwise around the center axis L3 between the pair of roller supports 64a and 64b, the rolling element 44 contacts the first contact surface 68a via the end of the first opposing surface 71a located toward the second arcuate surface 72b, as shown by the two-dot chain lines. Furthermore, the rolling element 44 contacts the second contact surface 68b via the end of the second opposing surface 71b located toward the first arcuate surface 72a. Thus, the limitation of the rotation of the rolling element 44 about the central axis L3 by the pair of roller supports 64a and 64b determines a sliding range A1 in which the peripheral surface of the rolling element 44 is slidable (can slide) on the inner peripheral surface 41c of the clutch housing 41.

[0040] As this is the case in the Fig. 2 and Fig. As shown in Fig. 6A, when the support member 43 constructed as above supports the two rolling elements 44, the two rolling elements 44 are separated (spaced apart) by an equiangular distance (in the present embodiment, it is a distance of 180°) in the rotation direction X1. The roller supports 64a and 64b that support the rolling elements 44 are inserted into the clutch housing 41. Thus, the rolling elements 44 face the clutch housing 41 inside the clutch housing 41. In addition, in each rolling element 44, the portion of the first arcuate surface 72a corresponding to the sliding area A1 (see Fig. Fig. 5), come into contact with the inner peripheral surface 41c of the clutch housing 41 between the pair of roller supports 64a and 64b. The support member 43 is configured to rotate relative to the clutch housing 41 in the rotation direction X1.

[0041] The rolling element release devices 57 of the drive-side rotating body 42 are inserted into the clutch housing 41 through an inner peripheral side of the ring 41 of the support member 43. Each rolling element release device 57 is arranged between the two rolling element retaining devices 62 and adjacent to the rolling element retaining devices 62 in the circumferential direction. Thus, opposite ends (elastic portions 58) of the rolling element release devices 57 in the rotational direction X1 face the first roller support 64a of one rolling element retaining device 62 and the second roller support 64b of the other rolling element retaining device 62 in the rotational direction X1. The support member 43 and the drive-side rotating body 42 are configured to rotate relative to each other in the rotational direction X1.When the drive-side rotating body 42 rotates, the rolling element release devices 57 come into contact with the roller supports 64a and 64b located further forward in the direction of rotation.

[0042] As this is the case in the Fig. 2 and Fig. 3, the driven side rotary body 45 is integral with the base end (upper end in Fig. 2) of the worm shaft 34 and is made of metal. The driven-side rotating body 45 has a control portion 81 and a driven-side coupling portion 82 arranged adjacent to each other in the axial direction. The driven-side coupling portion 82 is provided on a base side (upper side in Fig. 2) of the control section 81.

[0043] The control section 81 is formed integrally with the worm shaft 34 and is rod-shaped and extends in an axial direction of the worm shaft 34. The central axis of the control section 81 coincides with the central axis L2 of the worm shaft 34, so that the control section 81 is coaxial with the worm shaft 34. As shown in Fig. 6A, when viewed in a direction of the central axis L2, the control portion 81 has a point-symmetric shape about a central axis L2 of the worm shaft 34.

[0044] The peripheral surface of the control portion 81 includes two control surfaces 83. The control surfaces 83 are formed at two positions on the peripheral surface of the control portion 81, which are spaced apart by an equiangular distance (in the present embodiment, a distance of 180°). The control surfaces 83 are flat and parallel to the axial direction and perpendicular to a radial direction of the driven-side rotating body 45. The two control surfaces 83 are parallel to each other. Each control surface 83 is longer than the rolling elements 44 in the axial direction.

[0045] As this is the case in the Fig. 2 and Fig. 6B, the driven-side coupling portion 82 is rod-shaped and extends in the axial direction of the worm wheel 34. The central axis of the driven-side coupling portion 82 coincides with the central axis L2 of the worm shaft 34, so that the driven-side coupling portion 82 is coaxial with the worm shaft 34. The driven-side coupling portion 82 is slightly thinner than the driven-shaft insertion hole 54. The driven-side coupling portion 82 has an elliptical cross-section perpendicular to the axial direction. The cross-sectional shape is uniform in the axial direction. When viewed axially, the direction of the long side of the driven-side coupling portion 82 is parallel to the control surfaces 83, and the direction of the short side of the driven-side coupling portion 82 is perpendicular to the control surfaces 83 (see also Fig. 6A). As in Fig. 6B, when viewed in the direction of the center axis L2, the driven-side coupling portion 82 has a point-symmetric shape around the center axis L2 of the worm shaft 34.

[0046] The peripheral surface of the driven-side coupling portion 82 includes two first driven-side transmission surfaces 84 and two second driven-side transmission surfaces 85. Of the two first driven-side transmission surfaces 84, one of the first driven-side transmission surfaces 84 is located on a side 180° opposite the other of the first driven-side transmission surfaces 84. The two first driven-side transmission surfaces 84 are flat and parallel to the axial direction and to each other. The distance between the first driven-side transmission surfaces 84 is equal to the distance between the two drive-side transmission surfaces 54a of the drive-side rotating body 42 in the driven shaft insertion hole 54.

[0047] The second driven-side transmission surfaces 85 are arranged between the two first driven-side transmission surfaces 84. One of the second driven-side transmission surfaces 85 is arranged on a side 180° opposite to the other of the second driven-side transmission surfaces 85. The two second driven-side transmission surfaces 85 are flat and parallel to the axial direction and to each other. The distance between the second driven-side transmission surfaces 85 is equal to the distance between the two drive-side transmission surfaces 54A of the drive-side rotating body 42 in the driven shaft insertion hole 54. The first driven-side transmission surfaces 84 and the second driven-side transmission surfaces 85 extend from one end to the other end of the driven-side coupling portion 82 in the axial direction.

[0048] As this is Fig. As shown in Figure 2, the above-described driven-side rotating body 45 is inserted into the clutch housing 41 and the support member 43 from the opposite side to the drive-side rotating body 42. The driven-side rotating body 45 is coaxial with the clutch housing 41, the drive-side rotating body 42, and the support member 43.

[0049] As this is Fig. 6B, the driven-side coupling portion 82 is loosely fitted in the driven-shaft insertion hole 54 and configured to rotate integrally with the driving-side rotating body 42. The first and second elastic members 55 and 56 are interposed between the driven-side coupling portion 82, which is loosely fitted in the driven-shaft insertion hole 54, and the driven-shaft insertion hole 54. More specifically, the two second elastic members 56 are in contact with the longitudinally opposite ends of the driven-side coupling portion 82 when viewed axially. The four first elastic members 55 are interposed between the driving-side transmission surfaces 54a and each of the two first driven-side transmission surfaces 84 and the two second driven-side transmission surfaces 85.

[0050] When the drive-side rotating body 42 is rotated about the central axis relative to the driven-side rotating body 45, the drive-side transmission surfaces 54a elastically deform the first elastic members 55 and contact one of the first and second driven-side transmission surfaces 84 and 85. As a result, the drive-side rotating body 42 engages with the driven-side rotating body 45 in the rotational direction, and a rotational drive force of the drive-side rotating body 42 is transmitted to the driven-side rotating body 45.

[0051] As this is Fig. As shown in Fig. 6A, the control portion 81 of the driven-side rotating body 45 is inserted into the support member 43 so that the rolling elements 44 are disposed between the inner peripheral surface 41c of the clutch housing 41 and the respective control surfaces 83. The control portion 81 of the driven-side rotating body 45 radially opposes the clutch housing 41 and the rolling elements 44. More specifically, the support member 43 holds the rolling elements 44 between the inner peripheral surface 41c of the clutch housing 41 and the respective control surfaces 83 of the driven-side rotating body 45.

[0052] The distance between each cam surface 83 and the inner peripheral surface 41c of the clutch housing 41 (the clearance in the direction perpendicular to the cam surface 83) changes in the rotation direction of the driven-side rotating body 45. In the present embodiment, the distance between the cam surface 83 and the inner peripheral surface 41c of the clutch housing 41 is greatest at a circumferential center of the cam surface 83 and gradually decreases from the circumferential center to the circumferentially opposite ends of the cam surface 83. The distance between the circumferential center of the cam surface 83 and the inner peripheral surface 41c of the clutch housing 41 is larger than the maximum diameter D1 (see FIG. Fig. 5) of the rolling element 44. The distance between each circumferential end of the control surface 83 and the inner circumferential surface 41c of the clutch housing 41 is less than the maximum diameter D1 of the rolling element 44.

[0053] As this is Fig. As shown in Fig. 5, in the clutch 40 of the present embodiment, grease GR is applied to the inner peripheral surface 41c of the clutch housing 41. The grease GR also fills a space between the inner peripheral surface 41c of the clutch housing 41 and the first arcuate surfaces 72a of the rolling elements 44. When the rotating shaft 24 is not driven to rotate (that is, when the drive-side rotating body 42 is not driven to rotate), the grease GR increases the sliding friction between the inner peripheral surface 41c of the clutch housing 41 and the rolling elements 44. Fig. 5 shows schematically the section where the grease GR is located. The other drawings except Fig. 5 do not show the fat GR.

[0054] In the present embodiment, the distal surface of the support member 43 includes inclined portions 66a corresponding to a guide configured to guide the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 so that it is evenly applied to the inner peripheral surface 41c of the clutch housing 41 when inserted into the clutch housing 41.

[0055] More specifically, how this affects the Fig. 4A and Fig. 4B, the inclined portions 66a are formed on the distal surface of the coupling portions 66. Each inclined portion 66a is directed toward the base side (upper side in Fig. 4A) from the axial center (center axes L1 and L2) to a radially outer side. The inclined portion 66a is inclined at an angle such that the radially outer end of the inclined portion 66a is located at a base side (upper side in Fig. 4A) of the lower surface of the rolling element 44. The inclined portion 66a is arranged on a substantially entire area of ​​the part of the coupling portion 66 that is not provided with the retaining hook 67.

[0056] The inclined portion 66a guides the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 so that a radially inward movement of the grease GR on the distal surface of the clutch portion 66 is inhibited (hindered) when inserted into the clutch housing 41. In addition, when inserted into the clutch housing 41, the inclined portion 66a guides the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 and protrudes inward from the inner peripheral surface 41c so that the grease GR moves to the inner peripheral surface 41c of the clutch housing 41. In addition, when the support member 43 is inserted into the clutch housing 41, the inclined portion 66a guides the grease GR applied to a base side of the inner peripheral surface 41c of the clutch housing 41 to spread to a distal side of the inner peripheral surface 41c of the clutch housing 41.

[0057] As shown schematically in the Fig. 7A to 7C, a method of manufacturing the coupling 40 of the present embodiment includes an “application step” and an “insertion step”.

[0058] As this is Fig. 7A, in the application step before inserting the support member 43 into the clutch housing 41 of the grease GR on the base side (upper side in Fig. 7A) of the inner peripheral surface 41c of the clutch housing 41. In the application step, the grease GR is applied to the inner peripheral surface 41c of the clutch housing 41 along the entire circumference. In the application step, the grease GR is applied so that the base end (upper end in Fig. 7A) of the fat GR is located on a base side (upper side in Fig. 7A) of the base end of the inner peripheral surface 41c of the clutch housing 41 is located in an axial region opposite the rolling elements 44 (see Fig. 2). In other words, the grease GR is applied so that the base end (top end in Fig. 7A) of the grease GR is located between the base end of the inner peripheral surface 41c of the clutch housing 41 in the axial region facing the rolling elements 44 (see Fig. 2) and the base end (upper end in Fig. 7A) of the clutch housing 41. In addition, as shown schematically in Fig. 7A, the inclined portion 66a is set such that the radial distance Z1 from the inner peripheral surface 41c of the clutch housing 41 to the radially inner end of the inclined portion 66a is greater than a radial distance Z1 from the inner peripheral surface 41c of the clutch housing 41 to the radially inner end of the grease GR applied to the inner peripheral surface 41c. In other words, in the applying step, the grease GR is applied to the inner peripheral surface 41c of the clutch housing 41 such that the radial distance Z2 from the inner peripheral surface 41c of the clutch housing 41 to the radially inner end of the grease GR is smaller than the radial distance Z1 from the inner peripheral surface 41c of the clutch housing 41 to the radially inner end of the inclined portion 66a.

[0059] As this is the case in the Fig. 7B and Fig. 7C, in the insertion step carried out after the application step, the support member 43 is inserted into the clutch housing 41 so that the grease GR moves to the distal side (lower side in the Fig. 7A to 7C) of the inner peripheral surface 41c of the clutch housing 41. At this time, the grease GR is guided and evenly applied to the inner peripheral surface 41c of the clutch housing 41 by the action of the inclined portion 66a. Following the insertion step, for example, after the completion of the manufacture of the engine 10, when the engine 10 is driven to rotate the support member 43, the remaining grease GR located on the inclined portions 66a is directed toward the inner peripheral surface 41c of the clutch housing 41 by centrifugal force.

[0060] The actions of the engine 10 having the above-described structure and its operation are described below with particular attention to the actions and effects of the clutch 40.

[0061] As this is the case in the Fig. 2 and Fig. As shown in Fig. 8A, when the motor unit 20 is excited and driven, the drive-side rotating body 42 rotates together with the rotating shaft 24. That is, the drive-side rotating body 42 is driven to rotate. Fig. 8A and Fig. 8B show a case where the drive-side rotating body 42 is driven to rotate in a first direction R1. As shown in Fig. As shown in Fig. 8A, when the drive-side rotating body 42 rotates in the first direction R1, the circumferential end (the elastic portion 58) of each rolling element releasing device 57 of the drive-side rotating body 42, which is located forward in the rotation direction, comes into contact with the first roller support 64a of the corresponding one of the rolling element holding devices 62 and presses the first roller support 64a and the rolling element 44 in the first direction R1. As a result, the rolling elements 44 are located at the circumferential center of the respective cam surfaces 83 of the driven-side rotating body 45. More specifically, the rolling elements 44 enter an unlocked state in which the rolling elements 44 are not held between the clutch housing 41 and the cam surfaces 83 (that is, the rolling elements 44 do not interfere with the rotation of the driven-side rotating body 45).

[0062] In the unlocked state, as shown in Fig. 8B, the drive-side transmission surfaces 54a of the drive-side rotary body 42 contact the second driven-side transmission surfaces 85 of the driven-side coupling portion 82 in the first direction R1, so that the drive-side rotary body 42 and the driven-side rotary body 45 are coupled to rotate integrally with each other in the rotation direction X1. As a result, a rotational driving force of the drive-side rotary body 42 (rotation shaft 24) is transmitted to the driven-side rotary body 45 (worm shaft 34), and the rotary shaft 24 and the worm shaft 34 rotate integrally in the first direction R1.

[0063] At this point, as stated in the Fig. 5 and Fig. As shown in Fig. 8A, when the first roller supports 64a are pressed by the rolling element release devices 57 in the first direction R1, the support member 43 and the rolling elements 44 rotate together with the drive-side rotating body 42 and the driven-side rotating body 45 around the rotation axis (the same as the center axis L1) of the drive-side rotating body 42. Then, a frictional force between the inner peripheral surface 41c of the clutch housing 41 and the rolling elements 44 causes the rolling elements 44 to rotate between the pair of roller supports 64a and 64b in the opposite direction to the rotation direction of the support member 43 around the center axis L3.When the rolling elements 44 rotate about the central axis L3 by an amount allowed by the tolerance gap G1 between the roller supports 64a and 64b, the opposite sides of the rolling elements 44 come into contact with the roller supports 64a and 64b in the rotation direction X1. In the present embodiment, when the drive-side rotating body 42 is rotated in the first direction R1, each rolling element 44 comes into contact with the first contact surface 68a via the end of the first opposing surface 71a located toward the first arcuate surface 72a and comes into contact with the second contact surface 68b via the end of the second opposing surface 71b located toward the second arcuate surface 72b. Thus, the support member 43 limits the rotation of the rolling elements 44 about the central axis L3.Even if the drive-side rotating body 42 is driven to rotate and the rolling elements 44 rotate together with the drive-side rotating body 42 around the rotation axis of the drive-side rotating body 42, the rolling elements 44 are rotated around the center axis L3 in only the range allowed by the support member 43.

[0064] The rotation of the worm shaft 34 in the first direction R1 is reduced with respect to the speed between the worm shaft 34 and the worm wheel 37, and is transmitted to the output shaft 38 and output from the output shaft 38. According to the rotation direction of the output shaft 38, the vehicle window glass is raised and lowered via the window regulator (not shown in the drawings). When the excitation to the motor unit 20 is stopped, the driving and rotation of the rotary shaft 24 are stopped, that is, the driving and rotation of the drive-side rotating body 42 is stopped.

[0065] As this is the case in the Fig. 9A and Fig. 9B, in a state where the driving of the motor unit 20 is stopped, that is, when the rotary shaft 24 (drive-side rotary body 42) is not driven for the purpose of rotation, when a load is applied to the output shaft 38 from the load side (window regulator side in the present embodiment), the load causes the driven-side rotary body 45 to attempt to rotate. Fig. 9A and Fig. 9B shows a case where the driven-side rotating body 45 attempts to rotate in a second direction R2. The cam surfaces 83 of the driven-side rotating body 45 urge the rolling elements 44 located between the inner peripheral surface 41c of the clutch housing 41 and the cam surfaces 83 toward the outer side in the circumferential direction. In each rolling element 44 urged by the cam surface 83, the first arcuate surface 72a comes into contact with the inner peripheral surface 41c of the clutch housing 41 between the pair of roller supports 64a and 64b, and the second arcuate surface 72b comes into contact with a portion of the cam surface 83 located closer to the circumferential end (end of the cam surfaces 83 located rearward in the second direction R2) than the circumferential center of the cam surface 83.The rolling element 44 is held between the inner peripheral surface 41c of the clutch housing 41 and the portion of the cam surface 83 located toward the rear end in the second direction R2. As a result, the rolling elements 44 act as wedges and restrict the rotation (in the second direction R2) of the driven-side rotating body 45 (i.e., they lock the rotation of the worm shaft 34). Thus, when the rotating shaft 24 (drive-side rotating body 42) is not driven for rotation, the rotation of the output shaft 38 is restricted.The second driven-side transmission surfaces 85 of the driven-side clutch portion 82 are configured not to contact the drive-side transmission surfaces 54a of the drive-side rotary body 42 in the rotational direction (second direction R2) when the driven-side rotary body 45 is in the locking position (position where the rolling elements 44 are held between the driven-side rotary body 45 and the clutch housing 41) (in . Fig. 9A shown condition), as shown in Fig. 9B is shown.

[0066] Furthermore, when the motor unit (drive-side rotating body 42) is not driven for rotation, and the driven-side rotating body 45 attempts to rotate in the first direction R1, the rotation of the driven-side rotating body 45 is inhibited in the same way. Specifically, when each rolling element 44 is held between the inner peripheral surface 41c of the clutch housing 41 and a portion of the cam surface 83 located toward a rear end in the first direction R1, the rolling element 44 acts as a wedge and inhibits the rotation (in the first direction R1) of the driven-side rotating body 45 (i.e., it locks the rotation of the worm shaft 34).

[0067] If, as in the Fig. 2, Fig. 10A and Fig. 10B, the motor unit 20 is driven and the drive-side rotating body 42 rotates together with the rotating shaft 24 in the second direction R2, the clutch 40 couples the rotating shaft 24 to the worm shaft 34 in the same operation as when the drive-side rotating body 42 rotates in the first direction R1 (see FIG. Fig. 8), but each element rotates in the opposite direction. More specifically, when the drive-side rotating body 42 rotates in the second direction R2, the circumferential end (elastic portion 58) of each rolling element releasing device 57 of the drive-side rotating body 42, which is located forward in the rotation direction, comes into contact with the second roller support 64b of the corresponding one of the rolling element holding devices 62 and presses the second roller support 64b and the rolling element 44 in the second direction R2. As a result, the rolling elements 44 are located at the circumferential center of the respective cam surfaces 83 of the driven-side rotating body 45 and thus enter the unlocked state in which the rolling elements 44 are not held between the clutch housing 41 and the cam surfaces 83.In the unlocked state, when the drive-side transmission surfaces 54a of the drive-side rotary body 42 contact the driven-side first transmission surfaces 84 of the driven-side coupling portion 82 in the second direction R2, the rotational driving force of the drive-side rotary body 42 (rotation shaft 24) is transmitted to the driven-side rotary body 45 (worm shaft 34), and integrally rotates the rotary shaft 24 and the worm shaft 34 in the second direction R2.

[0068] At this point, as stated in the Fig. 5 and Fig. As shown in Fig. 10A, when the second roller supports 64b are pushed by the rolling element release devices 57 in the second direction R2, the support member 43 and the rolling elements 44 rotate together with the drive-side rotating body 42 and the driven-side rotating body 45 around the rotation axis of the drive-side rotating body 42. Then, a frictional force between the inner peripheral surface 41c of the clutch housing 41 and the rolling elements 44 causes the rolling elements 44 to rotate between the pair of roller supports 64a and 64b around the central axis L3 in the opposite direction to the rotation direction of the support member 43. When the rolling elements 44 are rotated about the central axis L3 by an amount permitted by the tolerance gap G1 between the roller supports 64a and 64b, the opposite sides of the rolling elements 44 come into contact with the roller supports 64a and 64b in the rotation direction X1.In the present embodiment, when the drive-side rotating body 42 is rotated in the second direction R2, each rolling element 44 contacts the first contact surface 68a via the end of the first opposing surface 71a located toward the second arcuate surface 72b, and contacts the second contact surface 68b via the end of the second opposing surface 71b located toward the first arcuate surface 72a. Thus, the support member 43 limits the rotation of the rolling elements 44 about the central axis L3. Even when the drive-side rotating body 42 is driven for rotation and the rolling elements 44 rotate together with the drive-side rotating body 42 about the rotation axis of the drive-side rotating body 42, the rolling elements 44 are rotated about the central axis L3 only within the range permitted by the support member 43.

[0069] When the rotation of the worm shaft 34 in the second direction R2 is transmitted to the output shaft 38 and output from the output shaft 38, the vehicle window glass is raised and lowered via the window regulator (not shown in the drawings) according to the rotation direction of the output shaft 38. When the excitation to the motor unit 20 is stopped, the driving and rotation of the rotary shaft 24 is stopped, that is, the driving and rotation of the drive-side rotary body 42 is stopped. After the driving of the motor unit 20 is stopped as described above, the rolling elements 44 act as wedges and inhibit the rotation of the driven-side rotary body 45 (that is, they lock the rotation of the worm shaft 34), thereby inhibiting the rotation of the output shaft 38 (see FIG. Fig. 9A).

[0070] The advantages of the present embodiment are described below.

[0071] (1) The distal surface of the support member 43 has the inclined portions 66a, which correspond to a guide configured to guide the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 so that it is evenly applied to the inner peripheral surface 41c of the clutch housing 41 when inserted into the clutch housing 41. When the support member 43 is coupled to the clutch housing 41, the grease GR is approximately evenly applied to the inner peripheral surface 41c of the clutch housing 41. This improves the initial characteristics of the clutch 40 and ultimately improves the initial characteristics of the engine 10. As a result, for example, a post-manufacturing characteristic test can be performed quickly with high accuracy.

[0072] (2) The inclined portions 66a are directed to the base side (upper side in Fig. 4A) is inclined from the axial center (center axes L1 and L2) toward the radially outer side. Upon insertion into the clutch housing 41, the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 is appropriately guided so that it is evenly applied to the inner peripheral surface 41c of the clutch housing 41. Specifically, for example, upon insertion into the clutch housing 41, radially inward movement of the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41 is inhibited. In addition, for example, the inclined portions 66a guide the grease GR, which is unevenly applied to the inner peripheral surface 41c of the clutch housing 41 and projects radially inward from the inner peripheral surface 41c, so that the grease GR moves toward the inner peripheral surface 41c of the clutch housing 41 when inserted into the clutch housing 41.In addition, for example, the grease GR applied to the base side of the inner peripheral surface 41c of the clutch housing 41 is guided to spread to the distal side of the inner peripheral surface 41c of the clutch housing 41 upon insertion into the clutch housing 41. The inclined portion 66a of the present embodiment is arranged so that the radially outer end of the inclined portion 66a is on the base side (upper side in . Fig. 4A) of the lower surface of the rolling element 44. When the support member 43 is rotated and the centrifugal force directs the remaining grease GR on the inclined portion 66a toward the inner peripheral surface 41c of the clutch housing 41, the grease GR is guided to the base side of the lower surface of the rolling element 44 (toward the center in the axial direction). The grease GR is effectively used to improve the characteristics of the clutch 40.

[0073] (3) The manufacturing method includes the application step of applying the GR grease to the base side of the inner peripheral surface 41c of the clutch housing 41, and the insertion step of inserting the support member 43 into the clutch housing 41 following the application step to distribute the GR grease to the distal side of the inner peripheral surface 41c of the clutch housing 41. As a result, when the support member 43 is coupled to the clutch housing 41, the GR grease is applied approximately evenly. This improves the initial performance of the clutch 40, and ultimately improves the initial performance of the engine 10.

[0074] The present embodiment may be modified as follows. The present embodiment and the following modified examples may be combined as long as the combined modified examples remain technically consistent with each other.

[0075] In the embodiment, the inclined portion 66a is used as a guide disposed on the distal surface of the support member 43. The guide can be changed to other configurations as long as the guide is configured to guide the grease GR, which is unevenly applied to the inner peripheral surface 41c of the clutch housing 41, so that it is evenly applied to the inner peripheral surface 41c of the clutch housing 41 when introduced into the clutch housing 41.

[0076] For example, the guide can be Fig. 11. In this example, a limiting wall 66b is arranged on the coupling portion 66 of the support member 43 and is used as a guide, which is located on a radially inner side and protrudes toward the distal side. The limiting wall 66b guides the grease GR unevenly applied to the inner peripheral surface 41c of the clutch housing 41, so that radially inward movement of the grease GR is inhibited when it is introduced into the clutch housing 41.

[0077] Also, with this structure, when the support member 43 is coupled to the clutch housing 41, the grease GR is applied approximately evenly to the inner peripheral surface 41c of the clutch housing 41, compared to a structure that does not have the guide (i.e., a structure in which the distal surface of the clutch portion 66 is simply flat). Specifically, when introduced into the clutch housing 41, radially inward movement of the grease GR, which is unevenly applied to the inner peripheral surface 41c of the clutch housing 41, is inhibited. Thus, compared to a structure that does not have the boundary wall 66b, the grease is guided to be applied evenly to the inner peripheral surface 41c of the clutch housing 41. This improves the initial performance of the clutch 44 and ultimately the initial performance of the engine 10.

[0078] As this is Fig.12, in addition to the inclined portion 66a of the embodiment, the boundary wall 66b may be arranged on a radially inner side of the inclined portion 66a.

[0079] In the embodiment, the manufacturing method is provided for a structure having the support member 43 having the distal surface including the guide (ie, the inclined portion 66a and the boundary wall 66b). The same manufacturing method can be applied to a structure having a support member that does not have a guide (ie, the distal surface of the coupling portion 66 is simply flat). Also in this structure, the grease GR is distributed to the distal side of the inner peripheral surface 41c of the coupling housing 41. When the support member is coupled to the coupling housing 41, the grease GR is applied approximately evenly.

[0080] In the exemplary embodiment, the present invention is implemented in the motor 10 having the clutch 40. The present invention may be implemented in a device other than the motor having the clutch 40.

[0081] The present invention is described according to exemplary embodiments, but is not limited to the examples and their constructions. The present invention includes various modified examples and variations within the scope of equivalents. Furthermore, various combinations and forms, and other combinations and forms comprising only one element or more or less than one element, are also within the scope of the present invention.

Claims

[1] Coupling (40) with: an annular coupling housing (41); a drive-side rotating body (42) constructed to be driven to rotate; a driven-side rotary body (45) to which the rotary drive force is transmitted from the drive-side rotary body (42); a rolling element (44) arranged between an inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45), wherein, when the driving-side rotating body (42) is driven for rotation, the rolling element (44) rotates together with the driving-side rotating body (42) about a rotation axis of the driving-side rotating body (42), and when the driving-side rotating body (42) is not driven for rotation, the rolling element (44) is held between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and inhibits rotation of the driven-side rotating body (45); a support member (43), wherein, when inserted into and fixed to the clutch housing (41) from a distal side, the support member (43) holds the rolling element (44) between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and rotates together with the driving-side rotating body (42) about the rotation axis of the driving-side rotating body (42); and Grease (GR) located between the inner peripheral surface (41c) of the clutch housing (41) and the rolling element (44), wherein the support element (43) has a guide (66a) arranged on a distal surface of the support element (43), the guide (66a) has an inclined portion (66a) which is inclined toward a base side from an axial center to a radially outer side, and the guide (66a) is constructed such that, when the grease (GR) is unevenly applied to the inner peripheral surface (41c) of the clutch housing (41), it guides the grease (GR) such that it is evenly applied to the inner peripheral surface (41c) of the clutch housing (41) when introduced into the clutch housing (41). [2] Engine with: a motor unit (20) having a rotary shaft (24) constructed to be driven for the purpose of rotation; the coupling (40) according to claim 1, having the drive-side rotating body (42) constructed to rotate integrally with the rotating shaft (24); and an output unit (30) having a driven shaft (34) configured to rotate integrally with the driven-side rotating body (45), the output unit (30) being configured to output a rotational driving force transmitted to the driven shaft (34). [3] A method of manufacturing a clutch (40) comprising: an annular clutch housing (41); a drive-side rotating body (42) configured to be driven for rotation; a driven-side rotating body (45) to which a rotational driving force is transmitted from the drive-side rotating body (42);a rolling element (44) arranged between an inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45), wherein, when the driving-side rotating body (42) is driven for rotation, the rolling element (44) rotates together with the driving-side rotating body (42) about a rotation axis of the driving-side rotating body (42), and when the driving-side rotating body (42) is not driven for rotation, the rolling element (44) is held between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and inhibits rotation of the driven-side rotating body (45);a support member (43) which, when inserted into and coupled to the clutch housing (41) from a distal side, holds the rolling element (44) between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and rotates together with the driving-side rotating body (42) about the rotation axis of the driving-side rotating body (42); and grease (GR) disposed at least between the inner peripheral surface (41c) of the clutch housing (41) and the rolling element (44), wherein the support member (43) has a guide (66a) disposed on a distal surface of the support member (43), and the guide (66a) has an inclined portion (66a) inclined toward a base side from an axial center to a radially outer side, the method comprising the following steps: Applying the grease (GR) to a base side of the inner peripheral surface (41c) of the clutch housing (41); and after application: inserting the support member (43) into the clutch housing (41), whereby the grease (GR) is distributed through the guide (66a) to a distal side of the inner peripheral surface (41c) of the clutch housing (41). [4] Coupling (40) with: an annular coupling housing (41); a drive-side rotating body (42) constructed to be driven to rotate; a driven-side rotary body (45) to which the rotary drive force is transmitted from the drive-side rotary body (42); a rolling element (44) arranged between an inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45), wherein, when the driving-side rotating body (42) is driven for rotation, the rolling element (44) rotates together with the driving-side rotating body (42) about a rotation axis of the driving-side rotating body (42), and when the driving-side rotating body (42) is not driven for rotation, the rolling element (44) is held between the inner peripheral surface (41c) (41c) of the clutch housing (41) and the driven-side rotating body (45) and inhibits rotation of the driven-side rotating body (45); a support member (43), wherein, when inserted into and fixed to the clutch housing (41) from a distal side, the support member (43) holds the rolling element (44) between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and rotates together with the driving-side rotating body (42) about the rotation axis of the driving-side rotating body (42); and Grease (GR) located between the inner peripheral surface (41c) of the clutch housing (41) and the rolling element (44), wherein the support element (43) has a guide (66b) arranged on a distal surface of the support element (43), the guide (66b) is constructed in such a way that, when the grease (GR) is unevenly applied to the inner peripheral surface (41c) of the clutch housing (41), it guides the grease (GR) in such a way that it is evenly applied to the inner peripheral surface (41c) of the clutch housing (41) when introduced into the clutch housing (41), the guide (66b) has a boundary wall (66b) located on a radially inner side and projecting toward a distal side, and the boundary wall (66b) is constructed such that, when the support element (43) is inserted into the clutch housing (41), it inhibits a radially inward movement of the grease (GR) which is unevenly applied to the inner peripheral surface (41c) of the clutch housing (41). [5] Engine with: a motor unit (20) having a rotary shaft (24) constructed to be driven for the purpose of rotation; the coupling (40) according to claim 4, having the drive-side rotating body (42) constructed to rotate integrally with the rotating shaft (24); and an output unit (30) having a driven shaft (34) configured to rotate integrally with the driven-side rotating body (45), the output unit (30) being configured to output a rotational driving force transmitted to the driven shaft (34). [6] A method of manufacturing a clutch (40) comprising: an annular clutch housing (41); a drive-side rotating body (42) configured to be driven for rotation; a driven-side rotating body (45) to which a rotational driving force is transmitted from the drive-side rotating body (42);a rolling element (44) arranged between an inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45), wherein, when the driving-side rotating body (42) is driven for rotation, the rolling element (44) rotates together with the driving-side rotating body (42) about a rotation axis of the driving-side rotating body (42), and when the driving-side rotating body (42) is not driven for rotation, the rolling element (44) is held between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and inhibits rotation of the driven-side rotating body (45);a support member (43) which, when inserted into and coupled to the clutch housing (41) from a distal side, holds the rolling element (44) between the inner peripheral surface (41c) of the clutch housing (41) and the driven-side rotating body (45) and rotates together with the driving-side rotating body (42) about the rotation axis of the driving-side rotating body (42); and grease (GR) disposed at least between the inner peripheral surface (41c) of the clutch housing (41) and the rolling element (44), wherein the support member (43) has a guide (66b) disposed on a distal surface of the support member (43), and the guide (66b) has a boundary wall (66b) located on a radially inner side and protruding toward a distal side, the method comprising the following steps: Applying the grease (GR) to a base side of the inner peripheral surface (41c) of the clutch housing (41); and after application: inserting the support member (43) into the clutch housing (41), whereby the grease (GR) is distributed through the guide (66b) to a distal side of the inner peripheral surface (41c) of the clutch housing (41), and inhibiting a radially inward movement of the grease (GR) unevenly applied to the inner peripheral surface (41c) of the clutch housing (41) by the boundary wall (66b).

Images