JP4950962B2 - Motor with reduction mechanism - Google Patents

Description

  The present invention relates to a motor with a speed reduction mechanism that transmits rotation to a driven member by reducing the rotation of a motor body by a speed reduction mechanism.

  As a drive source for an automatic opening / closing device for a vehicle such as a power window device or a sunroof device provided in a vehicle, a motor with a speed reduction mechanism having a motor body and a speed reduction mechanism as one unit is used. The motor with a speed reduction mechanism decelerates the rotation of the motor main body by a speed reduction mechanism consisting of a worm formed on the rotation shaft of the motor main body and a worm wheel meshing with the worm, and outputs the output of a wind glass or the like as a driven member. The motor is transmitted to the opening / closing body, and the motor with the speed reduction mechanism is designed to obtain a large output while being small.

  The motor with a speed reduction mechanism has a gear case in which a worm housing portion in which a worm of a rotating shaft is housed and a worm wheel housing portion in which a worm wheel is housed, and the worm and the worm wheel are a gear case. It is designed to mesh with each other. The worm wheel housing portion has a bottomed cylindrical shape, and the output cover that rotates together with the worm wheel protrudes from the opening portion of the worm wheel housing portion, and the bottom cover is assembled to the opening portion so that the worm wheel housing portion is Sealed.

When assembling the worm wheel housing part and the bottom cover, the bottom cover may be fixed to the worm wheel housing part by press-fitting, bonding, welding, etc., but it is easy to reassemble the worm wheel housing part and the bottom cover. In general, these are assembled by a plurality of locking structures that engage with the claws. For example, a groove (locking hole) is formed in a locking claw (locking portion) that extends from the outer peripheral portion of the bottom cover (flange portion) along the outer wall surface of the worm wheel housing portion (gear case), and Convex piece (claw part) that engages with the groove is provided on the outer wall surface of the worm wheel housing part, and the motor with a speed reduction mechanism that assembles the worm wheel housing part and the bottom cover by engaging the groove and the convex piece ( Patent Document 1 discloses a stepping motor with a gear head.
Japanese Utility Model Publication No. 62-165571

  In the conventional locking structure, a groove formed in the locking claw extending from the outer peripheral portion of the bottom cover so as to follow the outer wall surface of the worm wheel housing portion, and a protrusion provided on the outer wall surface of the worm wheel housing portion. The worm wheel housing part and the bottom cover are assembled by the piece, the engagement surface formed on the end face of the groove on the bottom cover side, and the engagement formed on the end face of the convex piece on the worm wheel housing part side. The mating surface is engaged. As shown in Patent Document 1, a predetermined gap is provided in the axial direction between the end surface on the opening side of the worm wheel housing portion and the bottom cover, and the bottom cover is attached to the worm wheel housing portion by this gap. It is possible to move the engagement surface of the groove and the engagement surface of the convex piece away from each other by moving the shaft relative to each other in the axial direction so that the bottom cover and the worm wheel housing portion can be easily disassembled and assembled. It has become.

  However, in that case, when the worm wheel housing part and the bottom cover are assembled, they can move relative to each other in the axial direction by the gap, and vibration is applied to the gear case, which causes relative vibrations, etc. There is a risk that noise due to looseness may occur between the worm wheel housing portion and the bottom cover.

  An object of the present invention is to suppress backlash between the bottom cover and the worm wheel housing portion.

  A motor with a speed reduction mechanism according to the present invention includes a yoke that rotatably supports an armature shaft, a worm shaft that rotates integrally with the armature shaft, and is provided with a worm, a worm housing portion that houses the worm shaft, and the worm A bottomed worm wheel housing portion for housing a worm wheel meshing with a shaft worm, a gear case to which the yoke is attached, a bottom cover covering an opening of the worm wheel housing portion, and the worm wheel housing portion; A motor with a speed reduction mechanism having a plurality of locking structures that engage with the bottom cover by pawls, the outer peripheral portion including an axial protrusion that protrudes in the axial direction toward the worm wheel housing portion, A sealing member that is provided on the bottom cover and seals between the bottom cover and the worm wheel housing portion; Wherein provided on the inner wall surface of the worm wheel housing portion, and having a return structure in which the axial projection is provided with a contact has been inclined surface for guiding the axial projections radially outward.

  A motor with a speed reduction mechanism according to the present invention includes a yoke that rotatably supports a rotating shaft provided with a worm, a worm accommodating portion that accommodates the worm, and a bottomed worm wheel that accommodates a worm wheel that meshes with the worm. A gear case to which the yoke is attached; a bottom cover that covers the opening of the worm wheel housing part; and a plurality of locking structures that engage the worm wheel housing part and the bottom cover with claws. A motor with a speed reduction mechanism, the outer peripheral portion including an axial protrusion projecting in the axial direction toward the worm wheel housing portion, provided on the bottom cover, and the bottom cover and the worm wheel housing portion A seal member that seals between the inner wall surface of the worm wheel housing portion, and the axial protrusion portion It is contact and having a return structure with slopes for guiding the axial projections radially outward.

  The motor with a speed reduction mechanism of the present invention is characterized in that the axial projection is provided corresponding to a location where the plurality of locking structures are provided.

  In the motor with a speed reduction mechanism according to the present invention, the outer peripheral portion of the seal member is provided with a radial protrusion that protrudes radially outward and contacts a seal surface provided on the inner wall surface of the worm wheel housing portion. Features.

  According to the present invention, the seal member is provided with the axial projection protruding in the axial direction, and the stepped portion provided with the inclined surface that abuts the axial projection and guides the axial projection outward in the radial direction is warmed. Since it is provided on the inner wall surface of the wheel housing portion, the axial play between the bottom cover and the worm wheel housing portion is suppressed, and the generation of noise due to the play can be prevented. In addition, since the axial protrusion is guided radially outward by the inclined surface, the axial protrusion is prevented from entering radially inward of the stepped portion, and the seal member is actively attached to the worm wheel housing portion. It is pressed against the inner wall surface, and the play is surely suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1 is a plan view of a power window motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, and FIG. 3 is an exploded perspective view of a gear portion.

  The power window motor 10 is provided in a power window device provided in a vehicle, and drives a window regulator (not shown) that moves a window glass up and down. The power window motor 10 is a motor with a speed reduction mechanism in which a motor main body 11 and a speed reduction mechanism for reducing the rotation of the motor main body 11 and transmitting it to the window regulator are combined into one unit. As shown in FIG. A motor main body 11 and a gear portion 12 having a speed reduction mechanism.

  The motor body 11 is a DC motor with a brush, and a rotating shaft 13 (shown by a broken line in FIG. 1) provided in the motor body 11 can rotate in the forward direction or the reverse direction. One end side (left side in FIG. 1) of the rotating shaft 13 is rotatably supported via a bearing (not shown) provided on the bottom wall of the bottomed cylindrical motor yoke 14 having an opening with one end opened. The motor body 11 is attached to the gear case 16 of the gear portion 12 by a plurality of bolts 15 at a flange portion 14a provided on the opening side of the motor yoke 14.

  The resin gear case 16 includes a worm accommodating portion 17 that extends in the axial direction of the rotating shaft 13 and opens toward the motor main body 11, and the motor main body 11 has an opening 17 a (see FIG. 3) of the worm accommodating portion 17. It is fixed to the end surface, and the other end side of the rotating shaft 13 is accommodated in the worm accommodating portion 17. A connector unit 62 and a brush holder 63 for supplying power to the motor main body 11 via a commutator 61 provided on the rotating shaft 13 are attached to the opening 17a of the worm housing portion 17, and the commutator 61, By supplying a drive current to the motor body 11 via the connector unit 62 and the brush holder 63, the rotary shaft 13 is driven to rotate in the forward direction or the reverse direction. The rotary shaft 13 has a split shaft structure composed of an armature shaft 13a that is rotatably supported by the motor yoke 14 and a worm shaft 13b that is rotatably supported by the worm housing portion 17, as shown in FIG. As shown, a worm 18 is integrally provided on a worm shaft 13b that rotates integrally with the armature shaft 13a.

  The gear case 16 includes a worm wheel housing portion 19 formed integrally with the worm housing portion 17, and the worm wheel housing portion 19 has teeth 20 a that engage with the worm 18 formed on the worm shaft 13 b formed on the outer peripheral portion. The worm wheel 20 is accommodated. The worm wheel housing portion 19 has a bottomed cylindrical shape having a bottom wall portion 19a formed in a disc shape and a cylindrical wall portion 19b extending in the axial direction of the output shaft 22 from the outer peripheral portion of the bottom wall portion 19a. The gear case 16 is open in a direction orthogonal to the opening 17a of the worm housing portion 17. As shown in FIGS. 2 and 3, a cylindrical portion 21 extending from the bottom wall portion 19 a toward the opening side is provided at the axial center of the worm wheel housing portion 19, and is formed in the cylindrical portion 21. In the through hole 21 a, an output shaft 22 formed longer than the height of the cylindrical wall portion 19 b from the bottom wall portion 19 a of the worm wheel housing portion 19 has a tip end portion of the worm wheel housing portion 19. It is fixed in a state of protruding from the opening.

  A boss portion 20b that is in sliding contact with the outer peripheral surface of the cylindrical portion 21 of the worm wheel housing portion 19 is provided at the radial center portion of the worm wheel 20 housed in the worm wheel housing portion 19, and this boss portion 20b. The worm wheel 20 is rotatably supported around the cylindrical portion 21 in the worm wheel housing portion 19. Further, the bottom wall portion 19a of the worm wheel housing portion 19 is provided with an annular convex portion 23 protruding toward the worm wheel 20 side, and the annular convex portion 23 is an end surface of the worm wheel 20 on the bottom wall portion 19a side. The worm wheel 20 is slidably supported.

  The worm wheel housing portion 19 is formed adjacent to the worm housing portion 17 so that the tangential direction of the cylindrical wall portion 19b of the worm wheel housing portion 19 and the axial direction of the rotary shaft 13 are substantially coincident with each other. A communication hole 24 that communicates the worm accommodating portion 17 and the worm wheel accommodating portion 19 is formed on the worm accommodating portion 17 side of the cylindrical wall portion 19 b of the accommodating portion 19. The worm 18 accommodated in the worm accommodating portion 17 and the tooth portion 20a of the worm wheel 20 accommodated in the worm wheel accommodating portion 19 are engaged with each other through the communication hole 24, and are engaged with each other inside the gear case 16. The worm 18 and the worm wheel 20 constitute a speed reduction mechanism. The speed reduction mechanism decelerates the rotational drive of the motor main body 11 to a predetermined speed and outputs a rotation with a high torque.

  In the power window motor 10 of the present embodiment, a worm wheel with a damper is adopted as a worm wheel constituting the speed reduction mechanism, and a damper member 26 and a follower plate 27 are assembled to the worm wheel 20 to form a worm wheel. The rotation of the wheel 20 is transmitted to the window regulator via the damper member 26 and the driven plate 27.

  Between the outer peripheral part where the tooth part 20a of the worm wheel 20 is formed and the boss part 20b formed at the radial center of the worm wheel 20, an annular shape opening toward the opening part side of the worm wheel housing part 19 is formed. A recess 28 is formed. As shown in FIG. 3, the worm wheel 20 includes three protrusions 29 protruding into the recess 28, and the recesses 28 are equally spaced by the protrusions 29 provided at equal intervals in the circumferential direction of the worm wheel 20. It is partitioned.

  A damper member 26 is attached to the recess 28. The damper member 26 has six elastic portions 26a formed at equal intervals in the circumferential direction, and connecting portions 26b for connecting the respective elastic portions 26a in an annular shape integrally on the inner peripheral side of the damper member 26. The elastic portions 26a are arranged adjacent to both sides in the circumferential direction of the projections 29 in the worm wheel 20, that is, two elastic portions 26a are accommodated between the projections 29. The end surfaces on both sides in the circumferential direction of each elastic portion 26a have an arc shape corresponding to the end surfaces on both sides in the circumferential direction of the projection 29, and when the damper member 26 is mounted in the recess 28, the elastic portions 26a are connected to each other. The worm wheel 20 has substantially the same shape as the projections 29 of the worm wheel 20, and the projections 29 of the worm wheel 20 are fitted into three of the six accommodations that are equally spaced in the circumferential direction. Is done.

  On the other hand, on the end surface of the driven plate 27 on the worm wheel 20 side, three protrusions 30 formed in substantially the same shape as the protrusions 29 of the worm wheel 20 are provided at equal intervals in the circumferential direction. The three projections 30 of the follower plate 27 are fitted into the other three accommodating parts to which the projections 29 of the worm wheel 20 are not fitted. That is, the protrusions 29 of the worm wheel 20 and the protrusions 30 of the driven plate 27 are alternately arranged at equal intervals in the recess 28 of the worm wheel 20, and the elastic part 26 a of the damper member 26 is fitted between them. It will be in the state. Thereby, the rotation of the worm wheel 20 is transmitted from the protrusion 29 of the worm wheel 20 to the protrusion 30 of the driven plate 27 via the elastic part 26 a of the damper member 26. Further, the driven plate 27 can rotate relative to the worm wheel 20 within a range where the elastic portion 26a of the damper member 26 is elastically deformed, and these are relatively rotated to elastically deform the damper member 26. The shock transmitted from the window regulator can be reduced.

  The driven plate 27 has a large diameter portion 27a that covers the opening side of the recess 28 in the worm wheel 20, and a small diameter portion 27b that protrudes from the radially inner side of the large diameter portion 27a toward the opening side of the worm wheel housing portion 19. The projections 30 described above are provided on the end surface of the large diameter portion 27a on the worm wheel 20 side so as to protrude in the direction opposite to the protruding direction of the small diameter portion 27b. As shown in FIG. 2, the small-diameter portion 27b has a gear hole 31a formed on an end face on one end side in the axial direction (upper side in the drawing), and the output gear 31 is fitted in the gear hole 31a.

  The output shaft 22 passes through the shaft center of the driven plate 27 and the output gear 31, and the driven plate 27 and the output gear 31 are rotatably supported by the output shaft 22. A groove 22a is formed on the outer peripheral surface of the portion of the output shaft 22 protruding from the output gear 31, and the driven plate 27 and the output gear 31 are locked by the locking member 32 locked to the groove 22a. It is biased toward the worm wheel 20 via an O-ring 33 made of an elastic material, and is supported between the worm wheel 20 and the locking member 32. The rotation transmitted from the rotating shaft 13 (armature shaft 13a, worm shaft 13b) of the motor body 11 to the driven plate 27 via the worm wheel 20 is driven by the output gear 31 that rotates together with the driven plate 27 to drive the wind regulator. The window glass is moved up and down.

  The small-diameter portion 27b of the driven plate 27 and the output gear 31 protrude from the opening of the worm wheel housing portion 19 toward one end in the axial direction, and the bottom cover 35 is assembled to the opening under the protruding state. The bottom cover 35 has a disc shape that covers the opening of the worm wheel housing portion 19, and a projection hole 35 a having a larger diameter than the small diameter portion 27 b of the driven plate 27 is formed on the radially inner side thereof. The small diameter portion 27b and the output gear 31 of the driven plate 27 protrude from the protrusion hole 35a.

  A seal member 36 made of an elastic material is attached to the back side of the bottom cover 35 (the worm wheel housing portion 19 side) by outsert molding, and the seal member 36 is formed on the radially inner side of the small diameter portion 27b of the driven plate 27. While being in sliding contact with the outer peripheral surface, it is pressed against the inner wall surface of the cylindrical wall portion 19b on the outer side in the radial direction, the worm wheel housing portion 19 is sealed, and rainwater or the like infiltrates into the worm wheel housing portion 19. It is prevented.

  Next, a locking structure for assembling the bottom cover 35 to the worm wheel housing part 19 will be described.

  4 is a perspective view of the bottom cover as seen from the back side, FIG. 5 is a cross-sectional view taken along line BB in FIG. 1, and FIG. 6 is an enlarged perspective view of a portion indicated by an arrow C in FIG. FIG. 7 is a sectional view taken along line DD in FIG.

  As shown in FIGS. 3 and 4, the bottom cover 35 has four locking claws 38 a and 38 b provided at equal intervals in the circumferential direction. The locking claw 38a, 38b is provided at a position where the worm housing portion 17 side, that is, the outer wall surface of the cylindrical wall portion 19b of the worm wheel housing portion 19 and the worm housing portion 17 overlap each other in the axial direction of the output shaft 22. The claw 38 a includes a pair of claw portions 39 that protrude radially outward from the outer peripheral portion of the bottom cover 35 and that protrude short toward the worm wheel housing portion 19. Each claw portion 39 is provided at a predetermined interval in the circumferential direction, and a groove 40 is formed between each claw portion 39. As shown in FIG. 5, an engagement portion 41 is provided at the tip of each claw portion 39 so as to protrude into the groove 40 from the side surface (inner surface) where the claw portions 39 face each other. An engagement surface 42 is formed on the end surface in the axial direction of the engagement portion 41 on the bottom cover 35 side.

  Of the locking claws 38a and 38b, the other three locking claws 38b provided on the side other than the worm accommodating portion 17 side protrude radially outward from the outer peripheral portion of the bottom cover 35 as shown in FIG. The wheel housing portion 19 extends toward the worm wheel housing portion 19 along the outer wall surface of the cylindrical wall portion 19b. A groove 44 is formed in the circumferential central portion of each locking claw 38b in the extending direction of the locking claw 38b except for the distal end portion 43, and on the axial end surface of the distal end portion 43 on the bottom cover 35 side. An engagement surface 45 parallel to the radial direction is formed.

  On the other hand, as shown in FIGS. 1 and 3, the worm wheel housing portion 19 has convex pieces 47a and 47b that are engaged with the engaging claws 38a and 38b of the bottom cover 35 at equal intervals in the circumferential direction. Is provided. Of the convex pieces 47a and 47b, the convex piece 47a provided on the worm accommodating portion 17 side corresponds to the groove 40 of the locking claw 38a, and the end face on the opening side of the cylindrical wall portion 19b (worm wheel accommodating portion 19). It protrudes from the bottom cover 35 side. As shown in FIG. 5, undercut portions 48 that are notched inward in the circumferential direction are formed at the base end portions on both sides in the circumferential direction of the convex piece 47a, and the tips on both sides in the circumferential direction of the convex piece 47a. An engaging portion 52 having an engaging surface 49 is formed on the portion so as to protrude outward in the circumferential direction from the undercut portion 48. The engagement surface 49 is a surface that is formed in a substantially vertical direction from the undercut portion 48 and forms the engagement portion 52. In addition, on the end surface on the opening side of the cylindrical wall portion 19b, a cutout portion 50 cut out toward the other end side in the axial direction (lower side in the drawing) is formed on both sides in the circumferential direction of the formation position of the convex piece 47a. Is formed. The engagement surface 49 is disposed so as to face the notch 50 and is formed on a surface obtained by extending the end surface on the opening side of the cylindrical wall portion 19b.

  Of the convex pieces 47a and 47b, the other three convex pieces 47b provided on the side other than the worm housing portion 17 side are the other axial end of the groove 44 of the locking claw 38b (lower side in the figure), as shown in FIG. Corresponding to the outer wall surface of the cylindrical wall portion 19b. The convex piece 47a has a shape that can be inserted into the other axial end side of the groove 44, and an engaging surface 51 extending in the radial direction is formed on the end face of the convex piece 47b on the other axial end side.

  The locking structure for assembling the bottom cover 35 to the worm wheel housing part 19 (gear case 16) is provided in each of the locking claws 38a and 38b (grooves 40 and 44) provided in the bottom cover 35 and the worm wheel housing part 19. Are formed by a plurality of locking structures that engage the claws, so that the bottom cover 35 and the worm wheel housing portion 19 can be disassembled and reassembled during maintenance or the like. It has become easy.

  As shown in FIG. 5, a locking claw 38a as a locking structure provided on the worm housing portion 17 side of the bottom cover 35 and a convex piece 47a formed on the gear case 16 are a pair of claw portions of the locking claw 38a. 39 is inserted into the notch 50 formed on the end surface of the cylindrical wall portion 19b on the opening side, and the convex piece 47a is inserted into the groove 40, and the engaging portion 41 of each claw portion 39 is engaged with the convex piece 47a. It is assembled by being hooked and fixed to the joint portion 52. That is, the engaging claw 38a and the convex piece 47a are fixed by engaging the engaging surface 42 of the engaging part 41 and the engaging surface 49 of the convex piece 47a in the claw part 39.

  On the other hand, as shown in FIG. 6, the locking claw 38 b and the convex piece 47 b as a locking structure provided on the side other than the worm housing portion 17 side insert the convex piece 47 b into the other axial end side of the groove 44. It is assembled by hooking and fixing the tip 43 of the pawl 38b to the convex piece 47b. That is, the engaging claw 38b and the convex piece 47b are fixed by engaging the engaging surface 45 of the tip 43 and the engaging surface 51 of the convex piece 47b.

  As described above, as the locking structure on the worm housing portion 17 side, the groove 40 including the engaging portion 41 protruding from the side surface is provided in the outer peripheral portion of the bottom cover 35 and is inserted into the groove 40 to be engaged with the engaging portion 41. Since the projecting piece 47a to be engaged is provided at the end of the worm wheel accommodating portion 19 on the opening side, it is possible to reduce the space in a smaller space as compared with the case where a locking structure including the locking claw 38b and the protruding piece 47b is provided. The locking structure can be provided without increasing the thickness of the gear case 16 even on the worm housing portion 17 side where the fixing is possible and a sufficient space cannot be secured on the outer wall surface of the cylindrical wall portion 19b. Therefore, by providing a locking structure on the worm housing portion 17 side, the interval between the respective locking structures can be reduced, and a sufficient locking force is provided between the worm wheel housing portion 19 and the bottom cover 35. Thus, the worm wheel housing part 19 is surely sealed.

  In addition, by providing a locking structure on the worm housing portion 17 side, each locking structure can be provided at equal intervals (symmetrical positions) in the circumferential direction of the worm wheel housing portion 19, and a balanced assembly is possible. In addition, it is possible to share the bottom cover 35 in the power window motor 10 of the power window device provided on both the left and right sides in the traveling direction of the vehicle.

  In the present embodiment, the locking structure constituted by the locking claw 38a (groove 40) and the convex piece 47a is applied only to the worm accommodating portion 17 side. Of course, it may be applied to the accommodating portion 17 side, and may be applied to the locking structure at other positions. Further, in the present embodiment, the grooves 40 and 44 are provided in the bottom cover 35, and the convex pieces 47a and 47b are provided in the worm wheel housing portion 19, but the convex pieces 47a and 47b are provided in the bottom cover 35, You may make it provide the groove | channels 40 and 44 in the edge part by the side of the opening part of the worm wheel accommodating part 19. FIG.

  As shown in FIG. 6, when the locking claw 38b and the convex piece 47b are assembled on the outer wall surface of the cylindrical wall portion 19b of the worm wheel housing portion 19, side surfaces on both sides in the circumferential direction of the locking claw 38b Wall portions 53 and 54 are provided to cover the distal end surface on one end side in the axial direction. The wall portion 53 that covers the side surface of the locking claw 38b is formed in the axial direction of the output shaft 22 from the end surface on the opening side of the cylindrical wall portion 19b to the end surface on the bottom wall portion 19a side, and the outer wall of the cylindrical wall portion 19b. The radial height dimension that is the protruding direction from the surface is the radial height dimension to the radially outer end face of the locking claw 38b formed on the bottom cover 35 (the radial height dimension of the locking claw 38b). The wall portion 53 has a shape that covers the entire side surface of the locking claw 38b.

  On the bottom wall portion 19a side of the cylindrical wall portion 19b, a wall portion 54 that covers the distal end surface of the locking claw 38b is formed in a direction approaching each other from the respective wall portions 53. The radial height dimension is formed larger than the radial height dimension of the locking claw 38b. The wall portion 54 is cut out in the center in the circumferential direction, and the locking claw 38b is pushed outward in the radial direction during maintenance or the like to disengage the groove 44 (the locking claw 38b) from the convex piece 47b. At this time, it is easy to put a finger on the tip 43 of the locking claw 38b.

  As described above, the wall portions 53 and 54 that cover the side surface and the distal end surface of the locking claw 38b disposed radially outside the outer wall surface of the cylindrical wall portion 19b are provided on the outer surface of the cylindrical wall portion 19b. After the worm wheel housing portion 19 and the bottom cover 35 are assembled, it is possible to prevent the locking claw 38b from being damaged or the locking claw 38b from being disengaged due to an object colliding with the locking claw 38b. Can do.

  In the present embodiment, the wall portion 54 that covers the distal end surface of the locking claw 38b has a shape in which the central portion in the circumferential direction is cut out, and the engagement is performed when the engagement between the groove 44 and the convex piece 47b is released. Although it is made easy to put a finger on the tip 43 of the pawl 38b, the wall 54 may cover the entire tip of the locking pawl 38b. Further, in the present embodiment, the height in the radial direction of the wall portions 53 and 54 is set so that the engagement claw 38b does not protrude radially outward from the wall portions 53 and 54. However, the wall portions 53 and 54 may be formed to have the same height in the radial direction as that of the locking claw 38b.

  As shown in FIG. 4, the sealing member 36 mounted on the back surface of the bottom cover 35 has two annular radial protrusions 56 projecting radially outward at the outer peripheral portion 36a (see FIG. 7), and a worm. There are four arc-shaped axial projections 57 projecting in the axial direction toward the wheel housing portion 19, and the axial projections 57 correspond to the locations where the locking claws 38 a and 38 b are provided. Are provided at equal intervals in the circumferential direction.

  On the other hand, as shown in FIG. 7, a cutout portion 58 that is partly cut out on the radially inner side is formed at the tip of the cylindrical wall portion 19 b of the worm wheel housing portion 19. An annular stepped portion 59 is provided as a turning structure on the inner wall surface of the tip of the. On the axial end surface of the stepped portion 59, a slope 60 is formed that inclines toward the other end side in the axial direction (lower side in the figure) as it goes radially outward.

  When the worm wheel housing part 19 and the bottom cover 35 are assembled, the outer peripheral part 36a of the seal member 36 enters the notch part 58 provided at the front end part of the cylindrical wall part 19b, and the radial protrusion 56 of the seal member 36. Is pressed against the seal surface 58a which is the radial end surface of the notch 58, and the axial projection 57 of the seal member 36 is pressed against the inclined surface 60 of the step 59. At this time, a predetermined gap D is formed between the bottom cover 35 and the front end surface of the cylindrical wall portion 19b. By providing this gap D, the axial projection 57 is pressed and shrunk to thereby bottom cover 35. Can be moved relative to each other in the axial direction toward the worm wheel housing portion 19 so that the engagement surface 45 of the engagement claw 38b and the engagement surface 51 of the convex piece 47b can be separated from each other. The bottom cover 35 can be easily disassembled and assembled.

  When the radial protrusion 56 is pressed against the sealing surface 58a of the cylindrical wall portion 19b, the worm wheel housing portion 19 is sealed and the bottom cover 35 may move relative to the worm wheel housing portion 19 in the radial direction. The radial play between the bottom cover 35 and the worm wheel housing part 19 is suppressed by the radial protrusions 56.

  On the other hand, when the axial projection 57 is pressed against the inclined surface 60 of the step 59, the axial projection 57 separates the bottom cover 35 and the worm wheel housing portion 19, that is, the engagement surface 45 of the engagement claw 38b. A tension load in the axial direction is applied in a direction to firmly engage the engagement surface 51 of the convex piece 47b. As a result, the bottom cover 35 is restrained from moving in the axial direction relative to the worm wheel housing portion 19, and the axial protrusion between the bottom cover 35 and the worm wheel housing portion 19 is prevented by the axial projection 57. Will be suppressed. Further, since the axial projection 57 is guided radially outward by the inclined surface 60, the axial projection 57 is prevented from entering radially inward of the stepped portion 59, and the seal member 36 is positively engaged. It comes to be pressed against the sealing surface 58a of the cylindrical wall portion 19b.

  In this way, the axial protrusion 57 that protrudes in the axial direction is provided on the outer peripheral portion of the seal member 36, and the inclined surface 60 that guides the axial protrusion 57 to the radially outer side when the axial protrusion 57 is pressed. Since the provided step portion 59 is provided on the inner wall surface of the worm wheel housing portion 19, the axial play between the bottom cover 35 and the worm wheel housing portion 19 is suppressed, and the generation of noise due to the play is prevented. be able to. Further, since the axial projection 57 is guided radially outward by the inclined surface 60, the axial projection 57 is prevented from entering radially inward of the stepped portion 59, and the seal member 36 is positively engaged. It is pressed against the seal surface 58a of the cylindrical wall portion 19b, and the play is surely suppressed.

  In the present embodiment, the arc-shaped axial projection 57 is provided at four locations corresponding to the locations where the locking claws 38a and 38b are provided, so that the axial projection 57 is provided in an annular shape. In contrast, although the axial tension load is reduced, the axial protrusion 57 may be provided in an annular shape.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above embodiment, the motor with the speed reduction mechanism of the present invention is applied to the power window motor 10 of the power window device that lifts and lowers the windshield of the vehicle, but the present invention is not limited to this. The present invention can also be applied to a drive source such as a wiper device or an electric sunroof device mounted on a vehicle.

  Moreover, in the said embodiment, although the DC motor with a brush is used for the motor main body 11 as a drive source, it is not restricted to this, The rotating shaft 13 can be rotationally driven in both forward and reverse directions. For example, a brushless electric motor or the like may be used.

  Furthermore, although the damper-equipped worm wheel is employed as the worm wheel of the speed reduction mechanism in the above-described embodiment, a damper-less worm wheel in which the damper member 26 and the driven plate 27 are not provided may be employed.

It is a top view of the power window motor which is one embodiment of the present invention. It is sectional drawing which follows the AA line in FIG. It is a disassembled perspective view of a gear part. It is the perspective view which looked at the bottom cover from the back side. It is sectional drawing which follows the BB line in FIG. It is an expansion perspective view of the part shown by the arrow C in FIG. It is sectional drawing which follows the DD line | wire in FIG.

Explanation of symbols

10 Power window motor (motor with reduction mechanism)
DESCRIPTION OF SYMBOLS 11 Motor main body 12 Gear part 13 Rotating shaft 13a Armature shaft 13b Worm shaft 14 Motor yoke 14a Flange part 15 Bolt 16 Gear case 17 Worm accommodating part 17a Opening part 18 Warm 19 Worm wheel accommodating part 19a Bottom wall part 19b Cylindrical wall part 20 Worm wheel 20a tooth portion 20b boss portion 21 cylindrical portion 21a through hole 22 output shaft 22a groove 23 annular convex portion 24 communication hole 26 damper member 26a elastic portion 26b connecting portion 27 driven plate 27a large diameter portion 27b small diameter portion 28 concave portion 29 protruding portion 30 protrusion Portion 31 Output gear 31a Gear hole 32 Locking member 33 O-ring 35 Bottom cover 35a Protrusion hole 36 Seal member 38a, 38b Locking claw 39 Claw portion 40 Groove 41 Engagement portion 42 Engagement surface 43 Tip portion 44 Groove 45 Engagement Surfaces 47a and 47b Convex piece 48 Undercut part 49 Engagement surface 50 Notch part 51 Engagement surface 52 Engagement part 53, 54 Wall part 56 Radial direction projection part 57 Axial direction projection part 58 Notch part 58a Seal surface 59 Stepped part (Return structure) )
60 slope 61 commutator 62 connector unit 63 brush holder D gap

Claims (4)

A yoke that rotatably supports the armature shaft;
A worm shaft that rotates integrally with the armature shaft and is provided with a worm;
A gear case that includes a worm housing portion that houses the worm shaft and a bottomed worm wheel housing portion that houses a worm wheel that meshes with the worm of the worm shaft;
A bottom cover that covers the opening of the worm wheel housing portion;
A motor with a speed reduction mechanism having a plurality of locking structures for engaging the worm wheel housing portion and the bottom cover with claws;
A seal member provided on the outer peripheral portion with an axial protrusion protruding in the axial direction toward the worm wheel housing portion, and provided between the bottom cover and the worm wheel housing portion,
A speed reduction mechanism provided on an inner wall surface of the worm wheel housing portion, and having a return structure provided with a slope that contacts the axial projection and guides the axial projection outward in the radial direction. With motor. A yoke that rotatably supports a rotating shaft provided with a worm;
A gear case to which the yoke is attached, comprising a worm housing portion for housing the worm, and a worm wheel housing portion having a bottom shape for housing a worm wheel meshing with the worm;
A bottom cover that covers the opening of the worm wheel housing portion;
A motor with a speed reduction mechanism having a plurality of locking structures for engaging the worm wheel housing portion and the bottom cover with claws;
A seal member provided on the outer peripheral portion with an axial protrusion protruding in the axial direction toward the worm wheel housing portion, and provided between the bottom cover and the worm wheel housing portion,
A speed reduction mechanism provided on an inner wall surface of the worm wheel housing portion, and having a return structure provided with a slope that contacts the axial projection and guides the axial projection outward in the radial direction. With motor.   3. The motor with a speed reduction mechanism according to claim 1, wherein the axial protrusion is provided corresponding to a place where the plurality of locking structures are provided. 4.   The motor with a speed reduction mechanism according to any one of claims 1 to 3, wherein an outer peripheral portion of the seal member projects against a seal surface provided on an inner wall surface of the worm wheel housing portion so as to protrude radially outward. A motor with a speed reduction mechanism, characterized in that a radial projecting portion is provided.

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