JP2009065789A - Electric motor with decelerating mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve an assembling property, to decrease the dispersion of rotating characteristics and to reduce the cost of an electric motor even in a structure unifying a motor unit and a gear unit. <P>SOLUTION: A cylindrical elastic member 40 transmitting the rotation of an armature shaft 15 to a decelerating shaft 29 is fitted between each projection section 37a of the decelerating shaft 29 and the connecting projecting section 38 of the armature shaft 15. Accordingly, the electric motor with a decelerating mechanism can be configured inexpensively. Since shaft displacements in assembling the shafts 15 and 29 are absorbed by the elastic deformation of the elastic member 40 and the assembling property can be improved, loads in the eccentric direction working to each shaft 15 and 29 are decreased and the generation of the dispersion of rotating characteristics can be suppressed. Since the impact of the armature shaft 15 is relaxed by the elastic member 40 during rotation of the armature shaft 15, the generation of abnormal sounds from the connecting sections of each shaft 15 and 29 is inhibited and a silent sound is attained. <P>COPYRIGHT: (C)2009,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.

  2. Description of the Related Art Conventionally, as a drive source for a power window device or a wiper device mounted on a vehicle such as an automobile, an electric motor with a speed reduction mechanism that can obtain a high output while being small is used. This electric motor with a speed reduction mechanism includes a motor main body and a gear case, an amateur having an armature shaft is rotatably accommodated in the motor main body, and a speed reduction mechanism composed of a worm and a worm wheel is accommodated in the gear case. ing.

As such an electric motor with a speed reduction mechanism, for example, a technique described in Patent Document 1 is known. In the electric motor with a speed reduction mechanism described in Patent Document 1, the motor unit and the gear unit are subassembled in separate assembly steps, and finally the units are integrated to form an electric motor with a speed reduction mechanism. The structure that completes is adopted. In other words, an armature shaft is provided on the motor unit side, and a speed reduction shaft with a worm integrally provided on the outer peripheral surface is provided on the gear unit side. These armature shaft and speed reduction shaft are integrated with each unit. By connecting, it is connected so that it can rotate integrally.
JP 2001-218420 A

  However, according to the technique described in Patent Document 1 described above, the axis of the motor shaft on the motor unit side and the axis of the reduction shaft on the gear unit side are deviated due to dimensional errors of components constituting the motor shaft. There is a case. Further, when there is a dimensional error or an assembly error in the axial direction between the amateur shaft and the deceleration shaft, there is a case where the connecting portion is loose when the shafts are connected so as to be integrally rotatable. When these shaft misalignments occur, it becomes difficult to connect the shafts and integrate the units. Even if the units can be integrated, a relatively large load is applied to the shafts in the eccentric direction. Therefore, the rotational characteristics of the electric motor with a speed reduction mechanism as a finished product may increase, resulting in variations in rotational characteristics.

  Therefore, in order to absorb the shaft misalignment that causes the above-mentioned problem, for example, an elastic body such as rubber formed so as to match the shape of the engaging portion is interposed at the connecting portion of the armature shaft and the speed reduction shaft. However, in this case, since an elastic body formed in a dedicated shape is used, it is disadvantageous when the cost of the electric motor is reduced.

  An object of the present invention is to provide an electric motor with a speed reduction mechanism that can improve assemblability, reduce variation in rotational characteristics, and reduce the cost of an electric motor even when the motor unit and the gear unit are integrated. It is to provide.

  The electric motor with a speed reduction mechanism according to the present invention is an electric motor with a speed reduction mechanism that outputs the motor rotation by decelerating the rotation of the armature by a speed reduction mechanism including a worm and a worm wheel, and the worm has an outer periphery provided on the armature. A reduction shaft provided integrally on the surface, and a recess having a pair of protrusions provided at one end of the armature shaft or the reduction shaft in the axial direction and projecting radially inward. The cross section is provided at the other axial end of either the armature shaft or the deceleration shaft, and is inserted from the axial direction between the protrusions of the recess and the tip is in contact with the bottom of the recess. A quadrangular convex portion, and when the convex portion is inserted into the concave portion, is provided between each of the protruding portions and the protruding portion to reduce the rotation of the armature shaft. Characterized in that it comprises an elastic cylindrical member for transmitting the.

  The electric motor with a speed reduction mechanism of the present invention is characterized in that the convex portion is inserted inside the elastic member via a predetermined gap.

  The electric motor with a speed reduction mechanism according to the present invention is characterized in that the elastic member is elastically deformed into an elliptical shape by the protrusions and attached to the recess.

  In the electric motor with a speed reduction mechanism according to the present invention, the rotation of the armature shaft is transmitted to the speed reduction shaft when any corner portion formed in the circumferential direction of the convex portion abuts on the elastic member. Features.

  The electric motor with a speed reduction mechanism according to the present invention is characterized in that a steel ball is mounted between the bottom of the concave portion and the tip of the convex portion.

  The electric motor with a speed reduction mechanism according to the present invention is a thrust adjusting means for adjusting the backlash in the thrust direction of each shaft on the opposite side to the connecting portion of each shaft of at least one of the armature shaft or the speed reduction shaft. It is characterized by providing.

  According to the present invention, when the convex portion is inserted into the concave portion, the cylindrical elastic member that transmits the rotation of the armature shaft to the deceleration shaft is provided between each projection portion and the convex portion. The deformation can absorb the shaft misalignment at the time of assembling each shaft and improve the assemblability, and can reduce the load in the eccentric direction acting on each shaft and suppress the occurrence of variation in rotational characteristics. it can. In addition, since the elastic member cushions the impact when the amateur shaft is rotated, the generation of noise from the connecting portion of each shaft can be suppressed and noise reduction can be achieved.

  According to the present invention, since the convex portion is inserted inside the elastic member via the predetermined gap, the assemblability of each shaft can be further improved. In this case, since the convex portion comes into contact with the elastic member, it is possible to suppress the generation of abnormal noise due to the gap.

  According to the present invention, the elastic member is elastically deformed into an elliptical shape by each protrusion and is attached to the recess, so that the elastic member can be held without dropping in a state of being attached to the recess. Therefore, it is possible to facilitate subassembly and further improve assemblability.

  According to the present invention, the rotation of the armature shaft is transmitted to the deceleration shaft when any corner portion formed in the circumferential direction of the convex portion contacts the elastic member, so that the elastic member is easily elastically deformed. And the buffer performance of the elastic member can be improved. Therefore, it is possible to further suppress the generation of abnormal noise from the connecting portion of each shaft.

  According to the present invention, since the steel ball is mounted between the bottom of the concave portion and the tip of the convex portion, the respective shafts can be brought into point contact with each other. Therefore, the resistance at the time of relative rotation of the respective axes can be reduced, and the occurrence of variations in rotational characteristics can be further suppressed.

  According to the present invention, the thrust adjusting means for adjusting the backlash in the thrust direction of each shaft is provided on the opposite side of the connecting portion of each shaft of at least one of the amateur shaft and the speed reduction shaft. It is possible to absorb the error and suppress the occurrence of backlash in the axial direction of each axis, and it is possible to further reduce the noise.

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

  1 is a cross-sectional view showing an electric motor with a speed reduction mechanism according to a first embodiment of the present invention, FIG. 2 is a partially enlarged view showing a broken-line circle A portion of FIG. 1 in an enlarged manner, and FIG. FIG. 4 is a partially enlarged view showing the broken-line circle B portion in an enlarged manner, FIG. 4 is a cross-sectional view of the connecting portion along the line CC in FIG. 3, and FIG. 5 is an explanatory view for explaining the assembly procedure of the connecting portion. ing.

  As shown in FIG. 1, an electric motor 10 with a speed reduction mechanism is used as a drive source of a power window device mounted on a vehicle such as an automobile. The electric motor 10 with a speed reduction mechanism includes a motor unit 11 and a motor unit 11. And a gear unit 12 to be integrated.

  The motor unit 11 has a motor yoke 13. The motor yoke 13 is formed in a bottomed cylindrical shape, and an armature 14 is rotatably accommodated therein. An amateur shaft 15 is fixed to the rotation center of the amateur 14, and both ends of the armature shaft 15 are rotated by a bearing 16 provided on the bottom 13a of the motor yoke 13 and a bearing 18 provided on the brush holder 17, respectively. It is supported freely. A thrust plate 19 and a steel ball 20 are disposed on the bottom 13a of the motor yoke 13, thereby restricting the movement of the armature shaft 15 in the thrust direction (right side in the figure).

  A pair of magnets 21 are fixed inside the motor yoke 13, and a magnetic field is formed inside the motor yoke 13 by each magnet 21. An armature core 22 is fixed to the armature shaft 15 so as to be positioned inside the magnetic field formed by each magnet 21, and an armature coil 23 is wound on the slot 22 a provided in the armature core 22 by overlapping winding. It is wound.

  A commutator 24 is fixed to the amateur shaft 15 adjacent to the amateur core 22, and a coil end of a corresponding amateur coil 23 is electrically connected to each segment piece 24 a of the commutator 24. The brush 25 held by the brush holder 17 is in sliding contact with the outer peripheral surface of the commutator 24. When a drive current from a controller (not shown) is supplied to the amateur coil 23 via the brush 25 and the commutator 24, the amateur core An electromagnetic force is generated in 22 so that the armature 14 (the armature shaft 15) rotates in a predetermined direction.

  The gear unit 12 includes a resin gear case 27 that is fixed to the open end of the motor yoke 13 by a screw member 26. A reduction mechanism 28 that decelerates and outputs the rotation of the armature 14 inside the gear case 27. Is housed. The speed reduction mechanism 28 includes a speed reduction shaft 29, and both ends of the speed reduction shaft 29 are supported by a pair of bearings 30, 31 provided on the gear case 27, so that the speed reduction shaft 29 is rotatable inside the gear case 27. It has become.

  As shown in FIG. 2, a steel ball 32 is accommodated in a recess 29 a formed at the tip (left side in the figure) of the speed reduction shaft 29, and this steel ball 32 contacts the thrust plate 33 mounted on the gear case 27. By contacting, the movement of the deceleration shaft 29 in the thrust direction (left side in the figure) is restricted.

  An accommodation recess 27a is provided at the tip (left side in the figure) of the gear case 27, and a resin member 34 as a thrust adjusting means is accommodated in the accommodation recess 27a. The resin member 34 is sealed with a predetermined pressure on the back surface side of the thrust plate 33, that is, on the side opposite to the steel ball 32 side of the thrust plate 33 through the sealing passage 27 b formed in the gear case 27. Has been solidified. The resin member 34 faces the thrust plate 19 mounted on the bottom portion 13a of the motor yoke 13 from the opposite side of the connecting portion of the shafts 15 and 29 in a state where the armature shaft 15 and the reduction shaft 29 are connected. Thus, the shafts 15 and 29 are pressed with a predetermined pressure, so that the play of the shafts 15 and 29 in the thrust direction is suppressed. However, the resin member 34 may be provided between the bottom 13a of the motor yoke 13 and the thrust plate 19, and may be provided on both the gear case 27 side and the motor yoke 13 side.

  As shown in FIG. 1, a worm 35 as a speed reduction mechanism is provided at a substantially intermediate portion in the longitudinal direction of the speed reduction shaft 29. The worm 35 is formed on the outer peripheral surface of the speed reduction shaft 29 formed of steel or the like. It is integrally formed by processing means such as rolling. However, the worm 35 may not be formed integrally with the reduction shaft 29 by rolling or the like. For example, a separate worm formed in another process may be mounted on the reduction shaft so as not to be relatively rotatable. .

  A worm wheel 36 as a speed reduction mechanism is rotatably accommodated in the gear case 27, and the worm 35 is engaged with a tooth portion 36 a of the worm wheel 36. An output shaft 36b is fixed to the rotation center of the worm wheel 36. The output shaft 36b protrudes outside from the gear case 27 and is connected to a driven member (not shown) such as a window regulator. It has become.

  As shown in FIG. 3, a connecting recess (recess) 37 is provided at the axial end of the speed reduction shaft 29 facing the armature shaft 15, and the axial end of the armature shaft 15 facing the speed reduction shaft 29 is provided. Is provided with a connecting convex portion (convex portion) 38. The armature shaft 15 and the reduction shaft 29 are connected by inserting the connecting convex portion 38 through the connecting concave portion 37 from the axial direction. Thus, in the electric motor 10 with a speed reduction mechanism, the armature shaft 15 and the speed reduction shaft 29 are formed separately, so that they can be formed in desired diameter dimensions and predetermined shapes, respectively.

  The connecting recess 37 is formed in a hole shape that is recessed at a predetermined depth in the axial direction so as to open the end of the speed reducing shaft 29 in the axial direction. As shown in FIG. 4, a pair of protrusions 37 a that protrude at a predetermined height are formed on the inner side of the connection recesses 37 so as to face the inner side in the radial direction. 38 is inserted from the axial direction. A steel ball 39 is mounted on the bottom 37b of the connection recess 37, and the tip of the connection protrusion 38 is in point contact with the steel ball 39. Therefore, the connecting convex portion 38 comes into contact with the bottom portion 37 b of the connecting concave portion 37 through the steel ball 39.

  As shown in FIG. 4, the connecting convex portion 38 is formed in a plate shape having a substantially quadrangular shape as shown in FIG. 4 by removing two predetermined portions of the axial end of the armature shaft 15. The tapered portion 38a (see FIG. 5) is integrally formed. A pair of flat surface portions 38b and a pair of arc portions 38c are provided on the outer peripheral surface of the connecting convex portion 38, and four corner portions 38d are provided therebetween. The length dimension of each plane part 38b of the connection convex part 38 is set smaller than the inner diameter dimension of the connection recessed part 37 and larger than the length dimension between the vertices of each projection part 37a. As a result, when the armature shaft 15 rotates relative to the speed reduction shaft 29, the relative rotation of the connecting convex portion 38 is restricted by each projection 37a, and as a result, the armature shaft 15 and the speed reduction shaft 29 rotate integrally. It has become.

  As shown in FIG. 4, a cylindrical elastic member 40 is provided between each protrusion 37 a and the connecting convex portion 38. The elastic member 40 is tubular with a thin steel material such as stainless steel, for example. Is formed. The elastic member 40 is provided between each projection 37a and the connection projection 38, so that the rotation of the connection projection 38 is transmitted to each projection 37a, that is, the rotation of the armature shaft 15 is transmitted to the deceleration shaft 29. It is supposed to be.

  The elastic member 40 has flexibility, and is mounted in the coupling recess 37 in a state of being elastically deformed into an elliptical shape by each projection 37a. The outer periphery of each elastic member 40 is connected to each projection 37a and the coupling recess 37. It is contact | abutted to the circular arc part. Thereby, the elastic member 40 can be held without dropping into the connecting recess 37. Further, the connecting convex portion 38 is inserted through the gap of a predetermined dimension on the inner peripheral side of the elastic member 40, so that the connecting convex portion 38 can be easily inserted into the elastic member 40. Yes.

  In the electric motor 10 with a speed reduction mechanism, the motor unit 11 and the gear unit 12 are assembled in a separate assembly process to form a subassembly, and then the armature shaft 15 and the speed reduction shaft 29 are connected to each other to connect the units 11 and 12. It is formed integrally. Hereinafter, a procedure for assembling the shafts 15 and 29 will be described.

  As shown in FIG. 5, first, a steel ball 39 is mounted on the bottom 37b of the connecting recess 37 in the speed reduction shaft 29, and a predetermined amount of grease (not shown) is applied. Thereafter, the elastic member 40 is mounted between the protrusions 37a while being elastically deformed. Then, the steel ball 39 is held without dropping to the bottom portion 37 b due to the viscous resistance of grease, and the elastic member 40 is held in the connecting recess 37. Under this state, the connecting projection 38 is inserted into the elastic member 40 to integrate the units 11 and 12.

  At this time, even if the shafts 15 and 29 of the units 11 and 12 are misaligned, the connecting convex portion 38 having the tapered portion 38a is inserted through the gap inside the elastic member 40, and the elasticity Since the member 40 can be elastically deformed, the axial deviation can be absorbed. Therefore, it is possible to reduce the load in the eccentric direction acting on each of the shafts 15 and 29 while improving the assemblability, and to suppress the variation in the rotational characteristics of the electric motor 10 with the speed reduction mechanism. .

  Next, the operation of the electric motor 10 with the speed reduction mechanism configured as described above will be described in detail with reference to the drawings.

  6 (a) and 6 (b) are operation diagrams showing the state of the elastic member during the normal rotation of the amateur shaft, and FIGS. 7 (a) and 7 (b) are operations showing the state of the elastic member during the reverse rotation of the amateur shaft. Each figure is shown.

  FIG. 6A shows an initial operation state. When the armature shaft 15 rotates in the direction of the arrow in the drawing, the connecting convex portion 38 is positioned with respect to the deceleration shaft 29 in the two-dot chain line in the drawing. Relative rotation in the same direction. Then, the connecting convex part 38 rotates by the gap between the elastic member 40 and the corner part 38 d on the diagonal of the connecting convex part 38 comes into contact with the inner side of the elastic member 40. Thereafter, the elastic member 40 is elastically deformed as shown in FIG. 6A by the contact of the corner portion 38d with the elastic member 40. Here, since the corner portion 38d comes into contact with the elastic member 40, the elastic member 40 is easily elastically deformed. Therefore, the generation of noise due to the contact of the corner portion 38d with the elastic member 40 is suppressed.

  When the elastic member 40 is elastically deformed, the elastic force (reaction force) acts on each projection 37a of the connecting recess 37, and the speed reduction shaft 29 is moved by the elastic force stored in the elastic member 40 as shown in FIG. Is rotated relative to the armature shaft 15 in the direction of the dashed arrow in the figure. Thereafter, with the corner portion 38d in contact with the inner side of the elastic member 40, the speed reduction shaft 29 rotates (forward rotation) together with the armature shaft 15, and the rotational force is transmitted to the outside via the speed reduction mechanism 28 (see FIG. 1). Communicated. However, when the external load resistance applied to the speed reduction mechanism 28 is large, the elastic member 40 is kept elastically deformed by the connecting convex portion 38.

  When the armature shaft 15 is rotated in the direction of the arrow in FIG. 7A from the state shown in FIG. 6B, the connecting convex portion 38 is indicated by a two-dot chain line in the drawing with respect to the deceleration shaft 29. Relative rotation in the same direction from the position. Then, the connecting convex part 38 rotates by the gap between the elastic member 40 and the corner part 38 d on the diagonal of the connecting convex part 38 comes into contact with the inner side of the elastic member 40. Thereafter, the elastic member 40 is elastically deformed as shown in FIG. 7A by the contact of the corner portion 38d with the elastic member 40. Here, since the corner portion 38d comes into contact with the elastic member 40, the generation of abnormal noise is suppressed as described above.

  When the elastic member 40 is elastically deformed, the elastic force (reaction force) acts on each projection 37a of the connecting recess 37, and the speed reduction shaft 29 is moved by the elastic force stored in the elastic member 40 as shown in FIG. Is rotated relative to the armature shaft 15 in the direction of the dashed arrow in the figure. Thereafter, with the corner portion 38d in contact with the inner side of the elastic member 40, the speed reduction shaft 29 rotates (reverses) together with the armature shaft 15, and the rotational force is transmitted to the outside via the speed reduction mechanism 28 (see FIG. 1). Is done. However, even in this case, the elastic member 40 is held in an elastically deformed state by the connecting convex portion 38 in accordance with the magnitude of the external load resistance applied to the speed reduction mechanism 28.

  According to the electric motor 10 with the speed reduction mechanism according to the first embodiment configured as described above, the rotation of the armature shaft 15 between each projection 37a of the speed reduction shaft 29 and the connecting convex portion 38 of the armature shaft 15. Since the cylindrical elastic member 40 that transmits the speed to the speed reduction shaft 29 is provided, the electric motor 10 with the speed reduction mechanism can be configured at low cost, and the shafts 15 and 29 are assembled by elastic deformation of the elastic member 40. Assembling can be improved by absorbing the shaft misalignment at the time, and the load in the eccentric direction acting on the shafts 15 and 29 can be reduced to suppress the occurrence of variations in rotational characteristics. Further, since the elastic member 40 cushions the impact when the armature shaft 15 is rotated, the generation of noise from the connecting portions of the shafts 15 and 29 can be suppressed and noise reduction can be achieved.

  Further, according to the electric motor 10 with the speed reduction mechanism according to the first embodiment, the connecting convex portion 38 is inserted through the elastic member 40 through a predetermined gap, so Assemblability can be further improved. In this case, since the connection convex part 38 contacts the elastic member 40, generation | occurrence | production of the noise by a clearance gap can be suppressed.

  Furthermore, according to the electric motor 10 with the speed reduction mechanism according to the first embodiment, the elastic member 40 is attached to the connecting recess 37 in a state of being elastically deformed into an elliptical shape by each protrusion 37a. The member 40 can be held without dropping in a state where the member 40 is mounted in the connecting recess 37. Therefore, it is easy to make a subassembly, and the assemblability can be further improved.

  Moreover, according to the electric motor 10 with the speed reduction mechanism according to the first embodiment, the rotation of the armature shaft 15 is decelerated by the corner portion 38d formed in the circumferential direction of the connecting convex portion 38 coming into contact with the elastic member 40. Since it is transmitted to the shaft 29, the elastic member 40 can be easily elastically deformed, and the buffering performance of the elastic member 40 can be improved. Therefore, generation | occurrence | production of the noise from the connection part of each axis | shaft 15 and 29 can be suppressed more.

  Further, according to the electric motor 10 with the speed reduction mechanism according to the first embodiment, the steel balls 39 are mounted between the bottom portion 37b of the connection concave portion 37 and the tip of the connection convex portion 38. Point contact can be made. Therefore, the resistance at the time of relative rotation of the shafts 15 and 29 can be reduced, and the occurrence of variations in rotational characteristics can be further suppressed.

  Further, according to the electric motor 10 with the speed reduction mechanism according to the first embodiment, the resin member 34 for adjusting the backlash in the thrust direction of the shafts 15 and 29 is provided on the side opposite to the connecting portion of the speed reduction shaft 29. Therefore, it is possible to absorb the dimensional error of each of the shafts 15 and 29 and to suppress the occurrence of backlash in the axial direction of each of the shafts 15 and 29, and to further reduce the noise.

  Next, a second embodiment of the present invention will be described in detail with reference to the drawings. FIG. 8 shows a cross-sectional view corresponding to FIG. 4 of the electric motor with a speed reduction mechanism according to the second embodiment of the present invention. In addition, about the part which has the same function as 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 8, in the second embodiment, as compared with the first embodiment, the inner side of the elastic member 40 and the connecting convex portion 38 under the non-operating state of the electric motor 10 with the speed reduction mechanism. This is different in that each corner portion 38d is in contact with each other (see the broken-line circle in the figure). In the case of connecting the shafts 15 and 29, since the tapered portion 38a (see FIG. 5) is formed at the tip of the connecting convex portion 38, the tapered portion 38a is connected to the elastic member 40. It plays the role which makes introduction of 38 smooth, and an assembly property does not fall.

  Also in the second embodiment configured as described above, substantially the same operational effects as those of the first embodiment described above can be achieved. In addition, according to the second embodiment, the elastic member 40 and the connecting projection 38 are in contact with each other under the non-operating state of the electric motor 10 with the speed reduction mechanism. It is possible to reliably suppress the generation of abnormal noise due to the protrusion 38 coming into contact with the elastic member 40.

  Next, a third embodiment of the present invention will be described in detail with reference to the drawings. FIG. 9 shows a partially enlarged view corresponding to FIG. 2 of the electric motor with a speed reduction mechanism according to the third embodiment of the present invention. In addition, about the part which has the same function as 1st Embodiment mentioned above, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  As shown in FIG. 9, in the third embodiment, as compared with the first embodiment, a so-called screw-in type, in which an adjustment screw 50 is screwed in place of the resin member 34 as a thrust adjusting means. The difference is that a thrust adjusting means is provided.

  A screw hole 51 into which the adjustment screw 50 is screwed is formed at the tip (left side in the figure) of the gear case 27. The adjustment screw 50 includes a screw portion 50a screwed to the screw hole 51, an O-ring mounting portion 50b to which an O-ring 52 for preventing rainwater and the like from traveling between the inside and the outside of the gear case 27 is mounted, And a screw head 50c. The adjustment screw 50 is formed with a tool fastening hole 50d to which a fastening tool (not shown) such as a hexagon wrench is attached so as to extend in the axial direction from the screw head 50c side. Further, a thrust plate 53 with which the steel ball 32 makes point contact is mounted on the screw portion 50 a of the adjustment screw 50. The thrust adjustment by the adjustment screw 50 is performed by screwing the adjustment screw 50 with a predetermined tightening torque after the motor unit 11 and the gear unit 12 are integrated.

  Also in the third embodiment configured as described above, it is possible to achieve substantially the same operational effects as those of the first embodiment described above. In addition, according to the third embodiment, a manufacturing apparatus that handles the molten resin is not required, and therefore the assembly process can be simplified.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. For example, in each of the above-described embodiments, the present invention is applied to the electric motor 10 with a speed reduction mechanism used as a drive source of the power window device. However, the present invention is not limited to this. The present invention can also 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.

  Further, in each of the above embodiments, the connecting convex portion 38 is provided at the axial end portion of the armature shaft 15 and the connecting concave portion 37 is provided at the axial end portion of the reduction shaft 29. Not limited to this, a connecting recess may be provided at the axial end of the armature shaft 15, and a connecting protrusion may be provided at the axial end of the reduction shaft 29.

  Further, in each of the above embodiments, the tip of the connecting convex portion 38 is shown in contact with the bottom portion 37b of the connecting concave portion 37 via the steel ball 39, but the present invention is not limited to this. The steel balls 39 may be omitted and the shafts 15 and 29 may be brought into direct contact with each other. Further, for example, a protrusion protruding toward the connection protrusion 38 may be integrally formed on the bottom 37b of the connection recess 37, and the tip of the connection protrusion 38 may be brought into contact with the protrusion.

It is sectional drawing which shows the electric motor with a speed-reduction mechanism which concerns on 1st Embodiment of this invention. It is the elements on larger scale which expand and show the broken-line circle | round | yen A part of FIG. It is the elements on larger scale which expand and show the broken-line circle | round | yen B part of FIG. It is a cross-sectional view of the connection part which follows the CC line of FIG. It is explanatory drawing explaining the assembly procedure of a connection part. (A), (b) is an action | operation figure which shows the state of the elastic member at the time of forward rotation of an amateur shaft. (A), (b) is an operation | movement figure which shows the state of the elastic member at the time of reverse rotation of an amateur shaft. It is a cross-sectional view corresponding to FIG. 4 of the electric motor with a speed reduction mechanism according to the second embodiment of the present invention. It is the elements on larger scale corresponding to FIG. 2 of the electric motor with a reduction mechanism which concerns on 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric motor with reduction mechanism 11 Motor unit 12 Gear unit 13 Motor yoke 13a Bottom part 14 Amateur 15 Amateur shaft 16 Bearing 17 Brush holder 18 Bearing 19 Thrust plate 20 Steel ball 21 Magnet 22 Amateur core 22a Slot 23 Amateur coil 24 Commutator 24a Segment piece 25 Brush 26 Screw member 27 Gear case 27a Accommodating recess 27b Enclosing passage 28 Deceleration mechanism 29 Deceleration shaft 29a Concave 30, 31 Bearing 32 Steel ball 33 Thrust plate 34 Resin member (thrust adjusting means)
35 Worm (Deceleration mechanism)
36 Worm wheel (deceleration mechanism)
36a Tooth part 36b Output shaft 37 Connection recess (recess)
37a Projection part 37b Bottom part 38 Connection convex part (convex part)
38a Taper part 38b Plane part 38c Arc part 38d Corner part 39 Steel ball 40 Elastic member 50 Adjustment screw (Thrust adjustment means)
50a Screw part 50b O-ring mounting part 50c Screw head 50d Tool fastening hole 51 Screw hole 52 O-ring 53 Thrust plate

Claims (6)

An electric motor with a speed reducing mechanism that decelerates and outputs the rotation of an amateur by a speed reducing mechanism comprising 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 recess having a pair of protrusions provided at one axial end of the armature shaft or the speed reduction shaft and projecting radially inwardly;
The armature shaft or the speed reduction shaft is provided at the other axial end portion, and is inserted in the axial direction between the projections of the recess and has a substantially square cross section with the tip abutting against the bottom of the recess. A convex part of the shape;
A cylindrical elastic member that is provided between each projection and the projection when the projection is inserted into the recess and transmits the rotation of the armature shaft to the deceleration shaft. An electric motor with a speed reduction mechanism.   2. The electric motor with a speed reduction mechanism according to claim 1, wherein the convex portion is inserted inside the elastic member through a predetermined gap.   3. The electric motor with a speed reduction mechanism according to claim 1, wherein the elastic member is elastically deformed into an elliptical shape by the protrusions and attached to the recess. 4.   The electric motor with a speed reduction mechanism according to any one of claims 1 to 3, wherein any one of angular portions formed in a circumferential direction of the convex portion comes into contact with the elastic member, thereby rotating the armature shaft. Is transmitted to the speed-reduction shaft.   5. The electric motor with a speed reduction mechanism according to claim 1, wherein a steel ball is mounted between the bottom of the concave portion and the tip of the convex portion. 6. .   The electric motor with a reduction mechanism according to any one of claims 1 to 5, wherein at least one of the armature shaft or the reduction shaft has a thrust on each shaft on the opposite side to the connecting portion of each shaft. An electric motor with a speed reduction mechanism, characterized in that a thrust adjusting means for adjusting backlash in a direction is provided.

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