JP2008167585A - Electric motor with reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric motor with a reduction gear effectively absorbing the axial backlash of an armature even if the reduction shaft with a worm is connected to an armature shaft. <P>SOLUTION: The reduction shaft 31 with a worm is formed independent of the armature shaft 16. A connecting projected part 45 mounted on the axial end portion of the armature shaft 16 is axially inserted into a connecting recessed part 44 provided on the axial end portion of the reduction gear shaft 31 so as to connect the armature shaft 16 with the reduction shaft 31. A roughly V-shaped elastic piece 51 equipped with a pair of elastic arm portions 51a, 51b is attached to the inside of the connecting recessed portion 44 to be brought in contact with the tip portion of the connecting projected part 45, thereby elastically deforming the elastic arm portions 51a, 51b in the radial direction. The elastic force of the elastic arm portions 51a, 51b energizes the connecting projected part 45 toward the outside of the connecting recessed portion 44. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric motor with a speed reduction mechanism that outputs the rotation of an armature by decelerating with a speed reduction mechanism including a worm and a worm wheel.

  As a drive source for a power window device or a wiper device provided in a vehicle, an electric motor that is operated by a power source such as a battery mounted on the vehicle is used. In order to adapt the electric motor to these devices, it is necessary to reduce the rotation of the motor to a required number of rotations. Therefore, the electric motor used for such an application is a motor unit with a speed reduction mechanism attached to the motor body, and is made into one unit as an electric motor with a speed reduction mechanism, and the rotation of the armature is reduced by the speed reduction mechanism and output. Yes.

  As the speed reduction mechanism, a small worm gear mechanism that can obtain a large speed reduction ratio is often used. In this case, the armature shaft provided on the armature also serves as the speed reduction shaft of the speed reduction mechanism. That is, the armature shaft is formed to have a length that protrudes from the motor yoke and reaches the inside of the gear case, and the worm is integrally formed on the outer peripheral surface of the portion of the armature shaft that protrudes into the gear case. The worm is engaged with a worm wheel that is rotatably accommodated in the gear case.

  However, in such an electric motor with a speed reduction mechanism, since the worm is formed by rolling the outer surface of the amateur shaft, the outer diameter of the worm can be formed to be larger than the outer diameter of the amateur shaft. Can not. For this reason, there has been a problem that restrictions on the design of the worm gear mechanism become large.

Thus, for example, in the electric motor with a speed reduction mechanism disclosed in Patent Document 1, a speed reduction shaft having a worm formed on the outer peripheral surface is provided separately from the armature shaft, and this speed reduction shaft can be rotated integrally with the tip of the armature shaft. I try to connect them. Accordingly, the worm can be formed to a desired outer diameter regardless of the outer diameter of the amateur shaft.
Japanese Patent Laid-Open No. 7-15913

  However, in the electric motor with a speed reduction mechanism as shown in Patent Document 1, the armature shaft, the speed reduction shaft, and the armature shaft are pressed into the fitting recess provided at the end of the speed reduction shaft in the axial direction from the axial direction. Are connected so as to be integrally rotatable, it is difficult to accurately set the shaft length in a state where the speed reduction shaft and the armature shaft are connected to a predetermined length. For this reason, it is necessary to separately provide a mechanism for preventing the axial play of the amateur in the motor yoke and the gear case that accommodates the amateur, and there has been a problem that the assembling work becomes complicated.

  In addition, if there is play in the connecting part between the deceleration shaft and the armature shaft, abnormal noise may be generated from this connecting part. In particular, in an electric motor in which the amateur can rotate in forward and reverse directions, the rotation direction is cut off. When the noise is changed, the noise is generated, and it is necessary to provide a mechanism for preventing the noise.

  An object of the present invention is to provide an electric motor with a speed reduction mechanism that can effectively absorb the backlash in the axial direction of an amateur even when the speed reduction shaft provided with a worm is connected to the armature shaft.

  An electric motor with a speed reduction mechanism according to the present invention is an electric motor with a speed reduction mechanism that outputs the rotation of an armature by decelerating by a speed reduction mechanism comprising a worm and a worm wheel. A reduction shaft provided integrally on the surface, a connecting recess provided at an axial end of either the armature shaft or the reduction shaft, and an axial end of the other of the armature shaft or the reduction shaft A connecting mechanism for connecting the armature shaft and the reduction shaft so as to be integrally rotatable with each other, and a pair of elastic arms connected to each other on one side. And an elastic piece that is mounted inside the coupling recess and biases the coupling projection toward the axially outer side of the coupling recess. It is characterized in.

  The electric motor with a speed reduction mechanism according to the present invention is characterized in that the pair of elastic arm portions are formed in a substantially V shape.

  The electric motor with a speed reduction mechanism according to the present invention is characterized in that the distal end portion of the connecting convex portion is brought into contact with the intermediate portion in the axial direction of the elastic arm portion to elastically deform the elastic arm portion in the radial direction of the armature shaft. To do.

  The electric motor with a speed reduction mechanism according to the present invention is characterized in that the distal end portion of the connecting convex portion is brought into line contact with the elastic arm portion.

  The electric motor with a speed reduction mechanism of the present invention is provided with a pair of recess-side detent surfaces facing the inner surface of the connecting recess with an axis interposed therebetween, and a pair of outer surfaces of the connecting projection facing the recess-side detent surface. And the elastic arm portion is disposed between the concave-side detent surface and the convex-side detent surface.

  In the electric motor with a speed reduction mechanism of the present invention, the elastic piece is provided with a flange portion extending in a radial direction from an end portion of the elastic arm portion, and the connection recess is provided outside the flange portion and the connection recess. A predetermined gap is provided in the axial direction between the armature shaft and the axial end of the reduction shaft.

  In the electric motor with a speed reduction mechanism according to the present invention, the elastic piece is provided with a folded portion by folding an end portion of the elastic arm portion 180 degrees, and the folded portion is provided between the connecting concave portion and the connecting convex portion. It is characterized by being elastically deformable in the radial direction of the amateur shaft.

  According to the present invention, the speed reduction shaft can be moved in the axial direction relative to the armature shaft while being urged by the elastic deformation of the elastic arm portion provided on the elastic piece. It is possible to effectively absorb the backlash in the axial direction of the amateur in a state where the armature shaft and the amateur shaft are connected. In addition, since the elastic arm portion can be elastically deformed in the radial direction and the rotational direction, it can absorb the axial deviation between the speed reduction shaft and the armature shaft and the backlash in the rotational direction. Can also be reduced.

  Further, according to the present invention, since the elastic arm portion is formed in a substantially V shape, the elastic arm portion can be more elastically deformed in the radial direction and the rotational direction, and the axial displacement between the deceleration shaft and the armature shaft can be reduced. These backlash in the rotation direction can be effectively absorbed.

  Furthermore, according to the present invention, the distal end portion of the connecting convex portion is brought into contact with the intermediate portion in the axial direction of the elastic arm portion so that the elastic arm portion is elastically deformed in the radial direction. Elastic force can be effectively applied between the amateur shaft.

  Furthermore, according to the present invention, the tip of the connecting convex portion is brought into line contact with the elastic arm portion, so that the operation of the contact portion can be made smooth.

  Furthermore, according to the present invention, the respective elastic arm portions are arranged between the recess-side detent surface provided on the inner surface of the coupling recess and the convex-side detent surface provided on the outer surface of the coupling convex portion. Therefore, an elastic force can be effectively applied between the reduction shaft and the amateur shaft by the substantially V-shaped elastic piece having a pair of elastic arm portions.

  Further, according to the present invention, a flange portion extending in a radial direction from the end portion is provided at the end portion of the elastic arm portion, and a predetermined interval is provided between the flange portion and the axial end portion of the armature shaft or the reduction shaft. Since the gap is provided, the flange portion can be provided without harming the elastic deformation of the elastic arm portion.

  Furthermore, according to the present invention, since the end portion of the elastic arm portion is provided with the fold-back portion that is elastically deformable in the radial direction, the axial deviation between the armature shaft and the reduction shaft and the play in the rotational direction are more effectively prevented. Can be absorbed.

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

  FIG. 1 is a sectional view showing an electric motor with a speed reduction mechanism according to an embodiment of the present invention. This electric motor 11 with a speed reduction mechanism is used as a drive source of a power window device for a vehicle. 12 and a speed reducer 13 attached thereto.

  The motor main body 12 includes a motor yoke (yoke) 14. The motor yoke 14 is formed in a cylindrical shape with a bottom having a substantially oval cross section, and an armature (armature) 15 is accommodated therein. The amateur 15 includes an armature shaft 16, and both ends of the armature shaft 16 are rotatably supported by a bearing 17 provided on the bottom portion 14 a of the motor yoke 14 and a bearing 19 provided on the brush holder 18. As a result, the armature 15 is rotatable together with the armature shaft 16 inside the motor yoke 14. Further, a steel ball 21 functioning as a thrust bearing is disposed on the bottom portion 14a of the motor yoke 14, and the armature shaft 16 moves in the axial direction when its axial end face abuts on the steel ball 21 (in FIG. 1). Movement to the right) is restricted.

  A pair of magnets 22 are fixed to the inner surface of the motor yoke 14, and a magnetic field is formed inside the motor yoke 14 by these magnets 22. An armature core 23 is fixed to the armature shaft 16 so as to be positioned inside the magnetic field formed by the magnet 22, and an armature coil 24 is wound on each of the plurality of slots 23 a provided in the armature core 23 by overlapping winding. It is wound. Further, a commutator (commutator) 25 is fixed to the armature shaft 16 adjacent to the armature core 23, and a coil end of the corresponding armature coil 24 is electrically connected to each segment piece 25a of the commutator 25. Has been. A pair of brushes (not shown) held by the brush holder 18 are in sliding contact with the outer peripheral surface of the commutator 25, and a drive current from a control device (not shown) is supplied to each amateur coil 24 via each brush and the commutator 25. Then, an electromagnetic force is generated in the amateur core 23, so that the armature 15, that is, the armature shaft 16 rotates in a predetermined direction.

  In addition, what is called a microcomputer provided with CPU, memory, etc. is used as a control apparatus.

  On the other hand, the speed reducer 13 includes a resin gear case 27 fixed to the opening end of the motor yoke 14 by a screw member 26, and a speed reduction mechanism 28 is accommodated in the gear case 27. The speed reduction mechanism 28 includes a speed reduction shaft 31, and both ends of the speed reduction shaft 31 are supported by a pair of bearings 32, 33 provided on the gear case 27, whereby the speed reduction shaft 31 is rotatable inside the gear case 27. It has become. Two steel balls 34, 35 are accommodated side by side in the axial direction in the recess 31 a formed at the tip of the speed reduction shaft 31, and the steel balls 34 arranged on the outside protrude from the recess 31 a and are attached to the gear case 27. By contacting the plate 36, the movement of the speed reduction shaft 31 in the axial direction (movement to the left in FIG. 1) is restricted. Further, the speed reduction shaft 31 is connected to the distal end portion of the armature shaft 16 by a connecting mechanism 37 at one end portion in the axial direction thereof, so that the speed reduction shaft 31 rotates together with the armature shaft 16, that is, rotates together with the armature shaft 16. It is like that. Details of the coupling mechanism 37 will be described later.

  The decelerating shaft 31 is provided with a worm 41 located substantially in the middle in the longitudinal direction. In the illustrated case, the worm 41 is formed integrally with the speed reduction shaft 31 by rolling or the like on the outer peripheral surface of the speed reduction shaft 31 formed of steel or the like. When the speed reduction shaft 31 rotates, the worm 41 together with the speed reduction shaft 31 is formed. Also comes to rotate. A worm wheel 42 is rotatably accommodated inside the gear case 27, and a worm 41 provided on the reduction shaft 31 is engaged with the worm wheel 42 inside the gear case 27. That is, the speed reduction mechanism 28 is a worm gear mechanism including a worm 41 and a worm wheel 42. An output shaft 43 is fixed to the shaft center of the worm wheel 42. The output shaft 43 protrudes outward from the gear case 27 and is connected to a driven member such as a window regulator (not shown).

  With such a configuration, for example, when a window opening / closing switch (not shown) is operated in the opening direction by a driver or the like, the armature 15 of the motor body 12, that is, the armature shaft 16 is rotated in the opening direction under the control of the control device. When the amateur shaft 16 rotates in the opening direction, the rotation is decelerated to a predetermined number of rotations by the speed reduction mechanism 28 and output from the output shaft 43. The output is transmitted to the door glass through the window regulator, and the door glass is Open operation. On the contrary, when the window opening / closing switch is operated in the closing direction, the armature shaft 16 reverses, the rotation is decelerated by the speed reduction mechanism 28 and output from the output shaft 43, and the door glass is closed.

  FIG. 2A is an exploded side view showing a state where the reduction shaft is removed from the amateur shaft, and FIG. 2B is a side view showing the amateur in a state where the reduction shaft is connected.

  As shown in FIG. 2A, the speed reduction shaft 31 constituting the speed reduction mechanism 28 is formed separately from the armature shaft 16 provided in the armature 15, and as shown in FIG. At the direction end, the connecting mechanism 37 is connected to the tip of the armature shaft 16 so as to be integrally rotatable. Here, the diameter d1 of the reduction shaft 31 is larger than the diameter d2 of the amateur shaft 16, and the diameter d3 of the worm 41 provided on the reduction shaft 31 is also larger than the diameter d2 of the amateur shaft 16. As described above, in the electric motor 11 with the speed reduction mechanism, the armature shaft 16 is moved to the worm 41 while forming the worm 41 in a desired outer diameter and shape by forming the speed reduction shaft 31 and the armature shaft 16 separately. It is possible to form a desired outer diameter with a smaller diameter.

  Next, a connection mechanism 37 for connecting the reduction shaft 31 to the amateur shaft 16 will be described.

  3A is a cross-sectional view showing the internal structure of the coupling mechanism shown in FIG. 1, and FIG. 3B is a cross-sectional view taken along line AA shown in FIG.

  As shown in FIG. 3, the coupling mechanism 37 includes a coupling recess 44 provided at an axial end portion of the speed reduction shaft 31 facing the armature shaft 16 and an axial end of the armature shaft 16 facing the speed reduction shaft 31. The connecting convex portion 45 is inserted into the connecting concave portion 44 from the axial direction, so that the connecting convex portion 45, the connecting concave portion 44, that is, the armature shaft 16 and the reduction shaft 31 are provided. It has a connected structure.

  The connection recess 44 is formed in a hole shape that opens at the axial end surface of the speed reduction shaft 31 and is recessed at a predetermined depth in the axial direction from the end surface. And a pair of recess-side detent surfaces 46 a and 46 b that are opposed to each other with the axis of the connection recess 44 interposed therebetween. Further, the portion of the inner surface of the connecting recess 44 that connects the recess-side detent surfaces 46 a and 46 b is a recess-side curved surface 47 that curves around the axis.

  FIG. 4 is a perspective view showing the details of the connecting convex portion shown in FIG. 3. The connecting convex portion 45 is a shaft of the armature shaft 16 by taking a predetermined range of the axial end portion of the armature shaft 16 in two directions. A pair of convex-side detent surfaces 48a, which are formed in a plate shape protruding in the axial direction from the direction end portion, and are formed in a flat shape on the outer surface of each of the outer surfaces and in parallel with the axis interposed therebetween. 48b is provided. The interval between the convex-side detent surfaces 48a and 48b is formed to be narrower than the interval between the concave-side detent surfaces 46a and 46b, so that when the connecting convex portion 45 is inserted into the connecting concave portion 44, FIG. As shown, each convex-side detent surface 48a, 48b faces the corresponding concave-side detent surface 46a, 46b in parallel, and each convex-side detent surface 48a, 48b and the concave side facing this A gap with a predetermined interval is formed between the rotation preventing surfaces 46a and 46b.

  Moreover, the part which connects each convex part side rotation-stop surface 48a, 48b of the outer surface of the connection convex part 45 becomes the convex part side curved surface 49 which curves around an axial center, respectively, These convex part side curved surface The diameter 49 is slightly smaller than the diameter of the concave-side curved surface 47. Thereby, when the connecting convex portion 45 is inserted into the connecting concave portion 44, the convex portion-side curved surface 49 is guided by the concave portion-side curved surface 47, and the connecting convex portion 45 is centered on the axial center with respect to the connecting concave portion 44. It can be rotated within a predetermined range.

  In order to bias the connecting convex portion 45 inserted through the connecting concave portion 44 toward the outside of the connecting concave portion 44, an elastic piece 51 is mounted inside the connecting concave portion 44.

  FIG. 5 is a perspective view showing details of the elastic piece. The elastic piece 51 is formed in a substantially V shape by bending a belt-shaped leaf spring material at an acute angle at an intermediate portion, and each V-shaped piece portion. Are elastic arm portions 51a and 51b, respectively. The elastic arm portions 51a and 51b are each formed in a flat plate shape, and a portion connecting the elastic arm portions 51a and 51b is a connecting portion 51c.

  As shown in FIG. 3, the elastic piece 51 is mounted inside the connection recess 44 so that the connection portion 51c contacts the bottom surface 44a of the connection recess 44. At this time, the connection portion 51c is in line contact with the bottom surface 44a. It has become. When the elastic piece 51 is attached to the connecting recess 44, the elastic arm portions 51a and 51b of the elastic piece 51 are respectively provided with the corresponding protrusion-side anti-rotation surfaces 48a and 48b and the recess-side anti-rotation surface 46a opposite thereto. , 46b. At this time, the clearance dimension between the convex-side detent surfaces 48a and 48b and the concave-side detent surfaces 46a and 46b facing the convex-side detent surfaces 48a and 48b is slightly wider than the thickness dimension of the elastic arm portions 51a and 51b. The elastic arm portions 51a and 51b are elastically deformable in the radial direction between the convex-side detent surfaces 48a and 48b and the concave-side detent surfaces 46a and 46b.

  Under the state where the movement of the amateur shaft 16 and the speed reduction shaft 31 in the axial direction is restricted by the steel balls 21, 34, 35, as shown in FIG. The elastic arms 51a and 51b are in a state of being elastically deformed in the radial direction by being in line contact with the substantially intermediate portion in the longitudinal direction of the arm portions 51a and 51b and being spread by the distal end portion of the connecting convex portion 45. Thereby, the connection convex part 45 is urged | biased by the axial direction toward the outer side of the connection recessed part 44 with the elastic force of the elastic arm parts 51a and 51b. Note that the distal end portion of the connecting convex portion 45 contacts the axial intermediate portion of the elastic arm portions 51a and 51b so as to elastically deform the elastic arm portions 51a and 51b in the radial direction, so that the elastic arm portion 51a. , 51b can efficiently apply elastic force to the connecting convex portion 45. Moreover, since the front-end | tip part of the connection convex part 45 comes in line contact with the elastic arm parts 51a and 51b, the operation | movement of the contact part with the elastic arm parts 51a and 51b of the connection convex part 45 is made smooth, and it is elastic. It is possible to more efficiently apply the elastic force to the connecting convex portion 45 by the arm portions 51a and 51b.

  Flange portions 52a and 52b extending in the radial direction from the end portions are integrally provided at the end portions of the elastic arm portions 51a and 51b on the side protruding from the connection recess 44, respectively. These flange portions 52a and 52b are respectively arranged outside the connection recess 44, and a predetermined gap is provided between the flange portions 52a and 52b and the axial end portion of the reduction shaft 31. Therefore, even if the elastic arm portions 51a and 51b of the elastic piece 51 are elastically deformed in the radial direction, the flange portions 52a and 52b come into contact with the axial end portion of the reduction shaft 31 and the elasticity of the elastic arm portions 51a and 51b. Deformation is not restricted.

  6A to 6C are cross-sectional views for explaining the axial backlash absorption function of the coupling mechanism, and FIGS. 7A to 7C are respectively the backlash absorption function of the coupling mechanism in the rotational direction. FIG. 8A to FIG. 8C are cross-sectional views for explaining the axis deviation absorbing function of the coupling mechanism.

  Next, based on FIGS. 6 to 8, the backlash absorbing function and the axial deviation absorbing function in the axial direction and the rotating direction by the coupling mechanism 37 will be described.

  When the amateur shaft 16 and the deceleration shaft 31 are positioned at regular positions in the axial direction, as shown in FIG. 6A, the distal end portion of the connecting convex portion 45 is located at the intermediate portion between the elastic arm portions 51a and 51b. The elastic arm portions 51a and 51b come into contact with each other and are urged toward the outside (right side in FIG. 6) of the coupling recess 44 by elastic deformation. Therefore, for example, due to dimensional errors of the motor yoke 14, the gear case 27, or the steel balls 21, 34, and 35, the restriction positions of the armature shaft 16 and the reduction shaft 31 by the steel balls 21, 34, and 35 are relatively separated from each other. 6B, as shown in FIG. 6B, the connecting projection 45 moves toward the outside of the connecting recess 44 by the elastic force of the elastic arms 51a and 51b. The armature 15 can be mounted inside the motor yoke 14 or the gear case 27 without creating a gap between the steel ball 21 and the steel ball 34 mounted on the speed reduction shaft 31 and the plate 36. On the other hand, for example, due to dimensional errors of the motor yoke 14, the gear case 27, or the steel balls 21, 34, 35, the restriction positions of the armature shaft 16 and the reduction shaft 31 by the steel balls 21, 34, 35 are relatively close to each other. 6C, the connecting projection 45 moves toward the inside of the connecting recess 44 against the elastic force of the elastic arms 51a and 51b, as shown in FIG. Thus, the armature 15 is mounted inside the motor yoke 14 or the gear case 27 without causing a gap between the armature shaft 16 and the steel ball 21 or between the steel ball 34 mounted on the speed reduction shaft 31 and the plate 36. can do. Moreover, since the backlash of the armature 15 in the axial direction can be absorbed, it is possible to prevent noise from the connecting portion.

  As described above, in the electric motor 11 with the speed reduction mechanism, the speed reduction shaft 31 is axially relative to the armature shaft 16 in a state in which the speed reduction shaft 31 is biased by elastic deformation of the elastic arm portions 51 a and 51 b provided on the elastic piece 51. Therefore, it is possible to effectively absorb the backlash in the axial direction of the armature 15 in a state where the speed reduction shaft 31 and the armature shaft 16 are connected.

  On the other hand, when the motor is in a stopped state, as shown in FIG. 7A, the convex-side detent surfaces 48a and 48b of the connecting convex portion 45 and the concave-side detent surfaces 46a and 46b of the connecting concave portion 44 are elastic arms. The parts 51a and 51b are held so as to be parallel to each other by the elastic force. Therefore, for example, as shown in FIGS. 7B and 7C, even if the connecting convex portion 45 rotates relative to the connecting concave portion 44 around the axis, the elastic arm portion 51a is accompanied by the relative rotation. , 51b are elastically deformed in the rotational direction, and the convex-side anti-rotation surfaces 48a, 48b of the connecting convex 45 and the concave-side anti-rotation surfaces 46a, 46b of the connecting concave 44 are held parallel to each other by the elastic force. Is done. Thereby, even if the connection convex part 45 inserted in the connection recessed part 44 has a backlash in the rotation direction with respect to the connection recessed part 44, the backlash can be absorbed by the elastic force of the elastic arm parts 51a and 51b. .

  As described above, in the electric motor 11 with the speed reduction mechanism, the elastic arm portions 51a and 51b can be elastically deformed in the rotational direction, and therefore, the backlash in the rotational direction between the speed reduction shaft 31 and the armature shaft 16 can be absorbed. .

  Furthermore, since the elastic arm portions 51a and 51b can be elastically deformed in the radial direction, as shown in FIG. As shown in (b) and (c), when the connecting convex portion 45 and the connecting concave portion 44 are relatively displaced from each other, the elastic arm portions 51a and 51b are elastically deformed in the radial direction and the shaft Misalignment can be absorbed.

  Thus, in this electric motor with a speed reduction mechanism, even if the armature shaft and the speed reduction shaft are misaligned, the backlash can be absorbed by the elastic arm portion elastically deforming in the radial direction.

  9A is a cross-sectional view showing a modification of the elastic piece shown in FIG. 3, and FIG. 9B is a cross-sectional view taken along the line AA shown in FIG. 9A.

  In the case shown in FIG. 3, the flange portions 52 a and 52 b are provided at the ends of the elastic arm portions 51 a and 51 b of the elastic piece 51, but in the case shown in FIG. 9, each elastic arm portion of the elastic piece 51 is provided. Folded portions 53a and 53b are provided at the ends of 51a and 51b in place of the flange portions 52a and 52b. The folded portions 53a and 53b are formed by folding the end portions of the elastic arm portions 51a and 51b inward by 180 degrees, and come into contact with the corresponding convex-portion-side detent surfaces 48a and 48b, respectively. Further, a gap is provided in the radial direction between the folded portions 53a and 53b and the end portions of the elastic arm portions 51a and 51b, so that the folded portions 53a and 53b are connected to the connecting concave portion 44 and the connecting convex portion 45. The armature 16 is elastically deformable between the radial direction and the rotational direction. Therefore, the folded portions 53a and 53b are elastically deformed in the radial direction, so that the axial deviation between the armature shaft 16 and the reduction shaft 31 and the play in the rotational direction can be more effectively absorbed.

  As described above, in the electric motor 11 with the speed reduction mechanism, the folded portions 53a and 53b that are elastically deformable in the radial direction are provided at the ends of the elastic arms 51a and 51b. The shaft misalignment and the play in the rotation direction can be absorbed more effectively.

  In FIG. 9, members corresponding to the members described above are given the same reference numerals.

  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-described embodiment, the present invention is applied to the electric motor 11 with a speed reduction mechanism used as a drive source of a vehicle power window device. However, the present invention is not limited to this, for example, a wiper device provided in a vehicle. The present invention may be applied to an electric motor with a speed reduction mechanism used for other purposes such as an electric motor with a speed reduction mechanism used as a drive source.

  Moreover, in the said embodiment, although the shape of the elastic piece 51 is made into the substantially V shape, if it comprises not only this but a pair of elastic arm part formed by connecting each one side, Other shapes may be used.

  Furthermore, in the said embodiment, although the connection convex part 45 is provided in the axial direction edge part of the armature shaft 16, and the connection recessed part 44 is provided in the axial direction edge part of the deceleration shaft 31, it is not restricted to this, The connecting concave portion 44 may be provided at the axial end portion of the amateur shaft 16, and the connecting convex portion 45 may be provided at the axial end portion of the reduction shaft 31.

  Furthermore, in the above-described embodiment, the worm 41 is integrally formed on the outer peripheral surface of the reduction shaft 31 by rolling or the like. However, the worm 41 is not limited to this. For example, the worm 41 formed separately is attached to the reduction shaft 31. Other structures may be used as long as the worm 41 is provided integrally with the reduction shaft 31 such as fitting and fixing to the outer peripheral surface.

It is sectional drawing which shows the electric motor with a reduction mechanism which is one embodiment of this invention. (A) is a decomposition | disassembly side view which shows the state from which the deceleration shaft was removed from the amateur shaft, (b) is a side view which shows the amateur in the state where the reduction shaft was connected. (A) is sectional drawing which shows the internal structure of the connection mechanism shown in FIG. 1, (b) is sectional drawing which follows the AA line shown to (a). It is a perspective view which shows the detail of the connection convex part shown in FIG. It is a perspective view which shows the detail of an elastic piece. (A)-(c) is sectional drawing for demonstrating the backlash absorption function of the axial direction of a connection mechanism, respectively. (A)-(c) is sectional drawing for demonstrating the play absorption function of the rotation direction of a connection mechanism, respectively. (A)-(c) is sectional drawing for demonstrating the misalignment absorption function of a connection mechanism, respectively. (A) is sectional drawing which shows the modification of the elastic piece shown in FIG. 3, (b) is sectional drawing which follows the AA line shown to (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Electric motor with reduction mechanism 12 Motor main body 13 Reduction gear 14 Motor yoke 14a Bottom 15 Amateur 16 Amateur shaft 17 Bearing 18 Brush holder 19 Bearing 21 Steel ball 22 Magnet 23 Amateur core 23a Slot 24 Amateur coil 25 Commutator 25a Segment piece 26 Screw member 27 Gear case 28 Deceleration mechanism 31 Deceleration shaft 31a Recess 32, 33 Bearing 34, 35 Steel ball 36 Plate 37 Connection mechanism 41 Worm 42 Warm wheel 43 Output shaft 44 Connection recess 44a Bottom surface 45 Connection projection 46a, 46b 47 Convex-side curved surfaces 48a, 48b Convex-side detent surfaces 49 Convex-side curved surfaces 51 Elastic pieces 51a, 51b Elastic arm portions 51c Connection portions 52a, 52b Flange portions 53a, 53b Folded portions 1~d3 diameter

Claims (7)

It is an electric motor with a speed reduction mechanism that decelerates and outputs the rotation of an amateur by a speed reduction mechanism consisting of a worm and a worm wheel,
An amateur shaft provided in the amateur;
A reduction shaft on which the worm is integrally provided on the outer peripheral surface;
A connecting recess provided at the axial end of either the armature shaft or the reduction shaft, and an axial end provided at the other axial end of the armature shaft or the reduction shaft are inserted into the connecting recess from the axial direction. A connecting mechanism for connecting the armature shaft and the reduction shaft so as to be integrally rotatable,
A pair of elastic arm portions connected to each other on one side, and having an elastic piece mounted inside the connection recess and biasing the connection protrusion toward the outside in the axial direction of the connection recess An electric motor with a speed reduction mechanism.   2. The electric motor with a speed reduction mechanism according to claim 1, wherein the pair of elastic arm portions are formed in a substantially V shape.   3. The electric motor with a speed reduction mechanism according to claim 1, wherein a distal end portion of the connecting convex portion is brought into contact with an intermediate portion in an axial direction of the elastic arm portion to elastically deform the elastic arm portion in a radial direction of the armature shaft. An electric motor with a speed reduction mechanism.   4. The electric motor with a speed reduction mechanism according to claim 3, wherein a tip end portion of the connecting convex portion is brought into line contact with the elastic arm portion.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 4, wherein a pair of recess-side detent surfaces facing each other with an axial center are provided on an inner surface of the connection recess, and an outer surface of the connection projection is provided. A pair of convex-side detent surfaces facing the concave-side detent surfaces are provided, and the elastic arm portions are respectively disposed between the concave-side detent surfaces and the convex-side detent surfaces. An electric motor with a reduction mechanism.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 5, wherein the elastic piece is provided with a flange portion extending in a radial direction from an end portion of the elastic arm portion, and the flange portion and the An electric motor with a speed reduction mechanism, wherein a predetermined gap is provided in an axial direction between the armature shaft provided with the connection concave portion outside the connection concave portion or an axial end portion of the speed reduction shaft.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 6, wherein the elastic piece is provided with a folded portion by folding an end portion of the elastic arm portion 180 degrees, and the folded portion is the connecting concave portion. An electric motor with a speed reduction mechanism, wherein the electric motor is elastically deformable in a radial direction of the armature shaft between the projection and the connecting convex portion.

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