JP2010098889A - Electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance durability of an electric motor of which the armature shaft is prevented from rotation caused by inverse input from an output shaft side. <P>SOLUTION: A seat motor 11 includes: a motor body 12 with the armature shaft 12b; a worm gear mechanism 21 for decelerating and for output of the rotation of the armature shaft 12b; a planetary gear mechanism 22 for decelerating and for output of the rotation of the worm gear mechanism 21 from an output shaft 14; and an inverse input interception clutch 24 which transmits the rotation of the worm gear mechanism 21 to the planetary gear mechanism 22 but does not transmit the rotation of the planetary gear mechanism 22 to the worm gear mechanism 21. The inverse input interruption clutch 24 is provided in a power transmission path between the worm gear mechanism 21 and the planetary gear mechanism 22. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric motor including a reverse input cutoff clutch that prevents rotation of an armature shaft due to input from an output shaft side.

  As a drive source of electrical components provided in a vehicle such as an automobile, an electric motor with a reduction gear that can obtain a large output with a small size is often used. For example, a two-stage reduction type electric motor is used as a seat motor (lifter motor) for driving a seat such as an automobile driver's seat in the vertical direction. In this case, the output of the motor body, that is, the rotation of the armature shaft is used. Is decelerated in two stages by a worm gear mechanism and a planetary gear mechanism and output from the output shaft.

  In such an electric motor, in order to prevent the motor from rotating due to an external load such as the weight of the occupant being input from the output shaft side while the motor is operating or the motor is stopped, Some have a reverse rotation prevention structure.

For example, Patent Document 1 includes a reverse input cutoff clutch that transmits the rotation of the armature shaft to the worm shaft and does not transmit the rotation of the worm shaft to the armature shaft between the armature shaft and the worm shaft. An electric motor is described that prevents rotation of the motor due to reverse input from.
JP 2007-221910A

  However, in the electric motor shown in Patent Document 1, since the reverse input cutoff clutch is provided between the armature shaft and the worm shaft, if there is reverse input to the motor from the output shaft side, the input load is reduced. The worm wheel is rotated through the output shaft, and the worm wheel is strongly engaged with the worm by the rotation. In particular, in the case of a seat motor, the weight of an occupant or the like is input from the output shaft as a reverse input, so that a large load is applied to the meshing portion between the worm wheel and the worm. Also, the worm wheel is usually made of resin with respect to the worm made of metal together with the worm shaft. In this case, if the worm wheel is strongly meshed with the worm due to a large reverse input load, There was a risk of damage to the gear.

  An object of the present invention is to improve the durability of an electric motor that prevents rotation of an armature shaft due to reverse input from the output shaft side.

  The electric motor of the present invention includes a motor main body having an armature shaft having a worm, a worm wheel that meshes with the worm and decelerates and outputs the rotation of the armature shaft, and is connected to the motor main body. A gear case in which a housing portion is formed, a planetary gear mechanism that is housed in the housing portion and decelerates the rotation of the worm wheel and outputs from the output shaft, and the worm wheel and the planetary gear housed in the housing portion And a reverse input shut-off clutch that is provided in a power transmission path between the mechanism and transmits the rotation of the worm gear mechanism to the planetary gear mechanism, and the rotation of the planetary gear mechanism is not transmitted to the worm gear mechanism.

  In the electric motor of the present invention, the reverse input cutoff clutch includes an outer ring that is fixed to the gear case, an inner ring that is arranged to rotate integrally with the planetary gear mechanism, and in which a plurality of mounting grooves are formed in the circumferential direction, and the worm A cage that is integrally rotatable with the wheel, is formed in an annular shape that is coaxial with the inner ring and the outer ring, and is formed between the outer ring and the inner ring, and a cage that is formed with a plurality of holding grooves in the circumferential direction; A holding spring disposed in the holding groove and the mounting groove; and a roller surrounded by the outer ring, the inner ring, the cage, and the holding spring, and the cage is provided at an end of the holding groove. The inner ring has a control surface for guiding the roller to the inner peripheral side, and the inner ring is formed such that the interval between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring gradually increases as the mounting groove approaches. The Characterized in that it has been an inner locking surface.

  The electric motor of the present invention is used as a seat motor for driving a vehicle seat in the vertical direction.

  An electric motor of the present invention includes a motor body having an armature shaft, a worm gear mechanism that decelerates and outputs the rotation of the armature shaft, a planetary gear mechanism that decelerates and outputs the rotation of the worm gear mechanism, and A reverse input cutoff clutch provided in a power transmission path between the armature shaft and the output shaft, transmitting the rotation of the armature shaft to the output shaft, and transmitting the rotation of the output shaft to the armature shaft; It is characterized by.

  According to the present invention, since the reverse input cutoff clutch is provided in the power transmission path between the worm gear mechanism and the planetary gear mechanism, the reverse input from the output shaft side is cut off before the worm gear mechanism by the reverse input cutoff clutch. The worm gear mechanism does not rotate. Thereby, it is possible to prevent the worm wheel from being strongly engaged with the worm by a large reverse input from the output shaft side, and it is possible to improve the durability of the electric motor. Further, since the reverse input from the output shaft side is accelerated by the planetary gear mechanism and is input to the reverse input cutoff clutch, the load input to the reverse input cutoff clutch can be reduced. Thereby, the capacity | capacitance of a reverse input interruption | blocking clutch can be made small, and this electric motor can be reduced in size.

  Further, according to the present invention, even when this electric motor is used as a seat motor, a large load due to the weight of an occupant or the like input from the output shaft side is blocked by the reverse input blocking clutch, and the worm wheel and the worm It is possible to prevent a large load from being applied to the meshing portion.

  Furthermore, according to the present invention, since the reverse input cutoff clutch is provided in the power transmission path between the armature shaft and the output shaft, it is possible to prevent the armature shaft from reversing due to the reverse input from the output shaft side. Can do.

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

  FIG. 1 is a perspective view showing a seat motor according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA shown in FIG.

  A seat motor 11 as an electric motor shown in FIG. 1 is also called a lifter motor, and is provided in a power seat device of a vehicle (not shown) such as an automobile so that a seat surface of a seat such as a driver's seat of the vehicle is vertically moved. To drive.

  The seat motor 11 is a motor with a speed reducer in which the motor main body 12 and the speed reducer 13 are formed as one unit, and the output of the motor main body 12 is decelerated by the speed reducer 13 and output from the output shaft 14. It has become. An output gear 15 is fixed to the output shaft 14, and this output gear 15 is connected to a vertical movement mechanism (not shown) of the power seat device. As a result, the motor main body 12 is operated and the output shaft 14 is rotated forward and backward so that the seat can be operated in the vertical direction.

  The motor main body 12 used for the sheet motor 11 is a brushed DC motor, and the yoke 12a is formed in a cylindrical shape with a bottom having a substantially oval cross section by pressing a steel material. An armature (not shown) is rotatably accommodated inside the yoke 12a. The armature shaft 12b constituting the armature is formed of a steel material, and is rotatably supported by the yoke 12a at one end thereof, and a portion in a predetermined range on the other end side, that is, the front end side protrudes from the opening end of the yoke 12a. Although not shown, an armature core around which an armature coil is wound and a commutator are fixed to the armature shaft 12b, and a brush holder unit having a pair of brushes slidably contacting the commutator is attached to the open end of the yoke 12a. It has been. When power is supplied to the armature coil via each brush and commutator, the motor main body 12 operates and the armature shaft 12b rotates in both forward and reverse directions.

  The speed reducer 13 includes a resin gear case 13a, and the gear case 13a is fixed to the opening end of the yoke 12a by a bolt 16a and a nut 16b. As shown in FIG. 2, the gear case 13a is formed with a bathtub-shaped accommodation portion 13b, and a portion of the armature shaft 12b on the tip side protrudes into the accommodation portion 13b. The housing portion 13b houses a worm gear mechanism 21 and a planetary gear mechanism 22, and the rotation of the armature shaft 12b is decelerated in two stages by the worm gear mechanism 21 and the planetary gear mechanism 22 and output from the output shaft 14. It is like that.

  Reference numeral 13c denotes a cover that is fixed to the opening portion of the gear case 13a by three fastening members 13d and closes the opening portion.

  As shown in FIG. 2, the worm gear mechanism 21 includes a worm 21a and a worm wheel 21b, and the worm 21a is integrally formed on the outer peripheral surface of a portion protruding into the accommodating portion 13b of the armature shaft 12b. That is, the worm 21a is formed of a steel material integrally with the armature shaft 12b. On the other hand, the worm wheel 21b is made of resin, and is disposed in the housing portion 13b at the shaft center thereof. The intermediate shaft 23 provided integrally with an inner ring 26 of the reverse input cutoff clutch 24 described later is connected to the intermediate shaft 23. It is mounted so that it can rotate relatively. The intermediate shaft 23 is disposed coaxially with the output shaft 14 inside the accommodating portion 13b, and one end thereof is supported by the cover 13c so as to be rotatable inside the accommodating portion 13b. A gear portion 21c is provided on the outer peripheral portion of the worm wheel 21b, and the worm wheel 21b is engaged with the worm 21a in the gear portion 21c. Thus, when the armature shaft 12b rotates, the rotation is decelerated by the worm gear mechanism 21 and is output as the rotation of the worm wheel 21b.

  As shown in FIG. 2, the accommodation portion 13 b is provided with a reverse input cutoff clutch 24, and the rotation of the worm gear mechanism 21, that is, the rotation of the worm wheel 21 b is transmitted to the intermediate shaft 23 via the reverse input cutoff clutch 24. It has become so. Details of the reverse input cutoff clutch 24 will be described later.

  The planetary gear mechanism 22 is a single pinion type, and includes a sun gear (sun gear) 22a, an internal gear (internal gear) 22b, and four (only two are shown in FIG. 2) planetary gears (planetary gears). 22c.

  The sun gear 22a is arranged coaxially with the worm wheel 21b and adjacent to the worm wheel 21b in the axial direction on the output gear 15 side. The sun gear 22a is fitted and fixed to the tip of the intermediate shaft 23 at the center of the shaft. It rotates with 23. In the illustrated case, the sun gear 22 a is fixed to the intermediate shaft 23, but the sun gear 22 a may be formed integrally with the intermediate shaft 23. The internal gear 22b is formed in a ring shape, is arranged coaxially with the sun gear 22a and aligned in the radial direction, and is fitted and fixed to the inner peripheral surface of the housing portion 13b of the gear case 13a at the outer peripheral portion thereof. The planetary gears 22c are respectively disposed between the sun gear 22a and the internal gear 22b and are arranged at equal intervals in the circumferential direction, and are engaged with the sun gear 22a and the internal gear 22b, respectively. Each planetary gear 22c is rotatably supported by a pin member 22e on a disk-shaped carrier 22d, and the carrier 22d is fixed to the output shaft 14 at its axis.

  As described above, the planetary gear mechanism 22 is configured as a speed reduction mechanism using the sun gear 22a as an input element and the planetary gear 22c (carrier 22d) as an output element. 14 is output.

  FIG. 3 is a front view of the reverse input cutoff clutch shown in FIG. 2, and FIG. 4 is an enlarged front view showing an enlarged main part of the reverse input cutoff clutch shown in FIG.

  Next, the details of the reverse input cutoff clutch 24 will be described with reference to FIGS.

  First, the reverse input cutoff clutch is provided in the power transmission path between the input side and the output side, and the rotation input from the input side is transmitted to the output side in both forward and reverse directions. The rotation input from the output side is a clutch having a function of not transmitting the rotation in either the forward or reverse direction to the input side.

  In the present embodiment, the reverse input cutoff clutch 24 is provided in a power transmission path between the worm gear mechanism 21 and the planetary gear mechanism 22, that is, a power transmission path between the worm wheel 21b and the sun gear 22a. 12b, that is, the worm wheel 21b side is an input side, and the output shaft 14, that is, the sun gear 22a side is an output side. As a result, when the motor body 12 operates and the worm gear mechanism 21, that is, the worm wheel 21 b rotates, the rotation is transmitted to the sun gear 22 a, that is, the planetary gear mechanism 22 via the reverse input cutoff clutch 24. On the other hand, when a reverse input due to the weight of the occupant applied to the seat is applied to the output shaft 14 via the output gear 15, and the planetary gear mechanism 22, that is, the sun gear 22a rotates together with the output shaft 14, the rotation is reverse input. The worm wheel 21b, that is, the worm gear mechanism 21, is not transmitted to the worm wheel 21b, that is, the worm gear mechanism 21 by being disconnected by the cutoff clutch 24, and the worm wheel 21b, that is, the worm gear mechanism 21 does not rotate.

  Next, the structure of the reverse input cutoff clutch 24 will be described.

  As shown in FIGS. 2 and 3, the reverse input cutoff clutch 24 has an outer ring 25 and an inner ring 26.

  The outer ring 25 is formed of a steel material in a cylindrical shape and is arranged coaxially with the intermediate shaft 23, and an inner peripheral surface thereof is an outer lock surface 25a. As shown in FIGS. 1 and 2, a flange portion 25b extending radially outward of the outer ring 25 is integrally provided at an axial end portion of the intermediate shaft 23 in the outer ring 25. The flange portion 25b is a gear case. The outer ring 25 is fixed to the gear case 13a by being sandwiched between the cover 13c and fixed to the gear case 13a by the fastening member 13d together with the cover 13c.

  On the other hand, the inner ring 26 is formed in a substantially cylindrical shape by a steel material, and is disposed coaxially with a predetermined gap with respect to the outer ring 25 inside the outer ring 25. A boss portion 26 a is provided integrally with the inner ring 26, and the boss portion 26 a is fixed to the intermediate shaft 23. As a result, the inner ring 26 rotates together with the intermediate shaft 23.

  As shown in FIG. 3, a cage 27 is provided between the outer ring 25 and the inner ring 26. The cage 27 is formed of a steel material in a cylindrical shape coaxial with the outer ring 25 and the inner ring 26. Further, as shown in FIG. 2, a disc portion 27a is integrally provided at the axial end portion of the intermediate shaft 23 of the cage 27, and this disc portion 27a is opposed to the axial end surface of the worm wheel 21b. Are arranged. The disc portion 27a is integrally formed with an engaging convex portion 27b that protrudes in the axial direction toward the worm wheel 21b, and the worm wheel 21b is provided with an engaging concave portion 21d corresponding to the engaging convex portion 27b. When the engaging convex portion 27b is engaged with the engaging concave portion 21d, the disc portion 27a, that is, the retainer 27 is rotated together with the worm wheel 21b. As shown in FIGS. 3 and 4, the retainer 27 is formed with four retaining grooves 27c arranged at equal intervals in the circumferential direction. Each of the retaining grooves 27c has a pair of cylindrical rollers 28. Is arranged.

  The inner ring 26 is formed with four mounting grooves 26b corresponding to the holding grooves 27c of the retainer 27 arranged at equal intervals in the circumferential direction, and holding springs 31 are mounted in these mounting grooves 26b, respectively. Each of the holding springs 31 is formed in a U shape, and is mounted in the mounting groove 26b at a U-shaped bent portion. When the inner ring 26 rotates, the holding spring 31 rotates together with the inner ring 26 while being mounted in the mounting groove 26b. It is like that. Further, both end portions of each holding spring 31 protrude outward in the radial direction from the mounting groove 26b, and are arranged between a pair of rollers 28 arranged in the holding groove 27c of the corresponding retainer 27, respectively.

  As shown in FIGS. 3 and 4, the end surface of the retainer 27 facing the roller 28, that is, the inner surface of the retaining groove 27c facing the roller 28 is a control surface 27d, and each of the control surfaces 27d is a retainer. It is inclined in the direction facing the inner side with respect to the radial direction of 27 (the direction away from the roller 28 as it approaches the axial center of the retainer 27). Thus, when the cage 27 rotates, the roller 28 positioned on the front side in the rotation direction with respect to the control surface 27d is pushed by the control surface 27d and moves in the rotation direction, and is pushed by the control surface 27d and has a diameter. It moves inward (inner circumferential side) in the direction and leaves the outer lock surface 25a.

  Inner lock surfaces 26c are formed on both outer peripheral surfaces sandwiching the mounting groove 26b of the inner ring 26, respectively. These inner lock surfaces 26c face the outer lock surface 25a of the outer ring 25 with the corresponding rollers 28 interposed therebetween, and gradually approach the axial center of the inner ring 26 from the outer peripheral surface of the inner ring 26 toward the mounting groove 26b. Inclined. The radial distance between the inner lock surface 26c and the outer lock surface 25a is set wider than the outer diameter of the roller 28 at the end of the inner lock surface 26c on the mounting groove 26b side, and the inner lock surface 26c. At the end of the inner ring 26 on the outer peripheral surface side, the outer diameter of the roller 28 is set smaller. As a result, when the inner ring 26 rotates with the cage 27 stopped, the roller 28 on the rear side in the rotational direction with respect to the mounting groove 26b is wedged between the inner lock surface 26c and the outer lock surface 25a. The inner ring 26 is locked to the outer ring 25 via a roller 28 so as to be prevented from rotating.

  Next, the operation of the reverse input cutoff clutch 24 will be described.

  FIGS. 5 (a) and 5 (b) are explanatory views showing the operating state of the reverse input cutoff clutch when the motor body is operated, and FIGS. 6 (a) and 6 (b) are respectively applied with reverse input from the output shaft. It is explanatory drawing which shows the operating state of the reverse input interruption | blocking clutch when it is made.

  When the motor main body 12, that is, the armature shaft 12b rotates, the rotation is decelerated by the worm gear mechanism 21 and transmitted to the cage 27, and the cage 27 rotates in the clockwise direction in the drawing as shown in FIG. To do. When the cage 27 rotates, the corresponding one of the rollers 28 (left side in the figure) is pushed in the rotational direction by the one control surface 27d facing the front side in the rotational direction of each holding groove 27c, and the outer surface is locked by the inclination of the control surface 27d. Moving away from the surface 25 a, the roller 28 rotates together with the retainer 27. When the roller 28 rotates together with the cage 27, the rotation is transmitted to the inner ring 26 via the holding spring 31, and the inner ring 26 rotates together with the cage 27. At this time, the holding spring 31 is elastically deformed within a predetermined range. When the inner ring 26 rotates together with the cage 27, the rotation of the inner ring 26 is transmitted to the planetary gear mechanism 22 through the intermediate shaft 23, and the rotation is decelerated by the planetary gear mechanism 22 and output from the output shaft 14, that is, the output gear 15. Similarly, when the motor body 12 rotates in the opposite direction to that shown in FIG. 5A, the cage 27 rotates in the opposite direction, that is, in the counterclockwise direction in the figure, as shown in FIG. 5B. The inner ring 26 also rotates in reverse with the cage 27 via the other roller 28 (right side in the figure) and the holding spring 31. Then, the rotation is transmitted to the planetary gear mechanism 22 via the intermediate shaft 23, decelerated by the planetary gear mechanism 22, and output from the output shaft 14, that is, the output gear 15.

  That is, in the seat motor 11, when the motor body 12 is operated and rotation is input from the worm gear mechanism 21 side, the reverse input cutoff clutch 24 transmits the rotation to the planetary gear mechanism 22.

  On the other hand, in a state where the motor main body 12 is stopped, a reverse input due to the weight of the occupant applied to the seat is applied to the output shaft 14 via the output gear 15, and the planetary gear mechanism 22, that is, the sun gear 22 a together with the output shaft 14. When rotated, as shown in FIG. 6A, the rotation is transmitted through the intermediate shaft 23, and the inner ring 26 rotates counterclockwise in the figure. At this time, since the motor main body 12 is stopped, the cage 27 is also stopped. When the inner ring 26 rotates with the cage 27 stopped, one of the rollers 28 on the rear side in the rotation direction with respect to the mounting groove 26b (right side in the figure) is formed between the inner lock surface 26c and the outer lock surface 25a. The inner ring 26 is sandwiched between the inner ring 26 and the outer ring 25 via a roller 28. Accordingly, the rotation of the inner ring 26 is blocked by the outer ring 25 via the roller 28, and the rotation is not transmitted to the cage 27, that is, the worm wheel 21b (worm gear mechanism 21). Similarly, when the input from the output shaft 14 is in the direction opposite to that shown in FIG. 6A, the other side on the rear side in the rotational direction with respect to the mounting groove 26b (see FIG. 6B) (see FIG. 6B). The middle left roller 28 is sandwiched between the inner lock surface 26 c and the outer lock surface 25 a, and the inner ring 26 is locked to the outer ring 25 via the roller 28.

  That is, when the planetary gear mechanism 22 rotates due to reverse input due to the weight of the occupant applied to the seat, that is, when rotation is input from the planetary gear mechanism 22 side, the reverse input cut-off clutch 24 cuts off the rotation and the worm wheel 21b, The worm gear mechanism 21 is not transmitted. Therefore, even if a reverse input is applied from the output shaft 14, the worm wheel 21b does not rotate, the reverse input becomes excessive, and the gear portion 21c of the worm wheel 21b is strongly engaged with the worm 21a and is damaged. This can be prevented.

  As described above, in the seat motor 11, the reverse input cutoff clutch 24 is provided in the power transmission path between the worm gear mechanism 21 and the planetary gear mechanism 22, so that the reverse input from the output shaft 14 side is reverse input blocked. The clutch 24 can be shut off before the worm gear mechanism 21 to prevent the worm gear mechanism 21 from rotating. Thereby, it is possible to prevent the worm wheel 21b from being strongly engaged with the worm 21a due to a large reverse input from the output shaft 14 side and to be damaged, and to improve the durability of the seat motor 11.

  In the seat motor 11, the reverse input cutoff clutch 24 is provided in the power transmission path between the worm gear mechanism 21 and the planetary gear mechanism 22, so that the reverse input from the output shaft 14 side is increased by the planetary gear mechanism 22. It is input to the reverse input cutoff clutch 24 after being accelerated. Therefore, the load input to the reverse input cutoff clutch 24 is reduced by the speed increase by the planetary gear mechanism 22. Thereby, the locking force of the reverse input cutoff clutch 24, that is, the capacity required for locking, can be reduced, and the seat motor 11 can be reduced in size.

  FIG. 7 is an explanatory view showing the arrangement of the planetary gear mechanism and the reverse input cutoff clutch with respect to the worm gear mechanism.

  In the sheet motor 11, the yoke 12 a of the motor body 12 is formed in a substantially oval cross section in order to reduce the thickness thereof. The worm 21a is formed integrally with the armature shaft 12b, and the axial direction of the worm wheel 21b is matched with the direction in which the thickness of the yoke 12a is thin. Thereby, as shown in FIG. 7, the worm gear mechanism 21 is disposed at the intermediate position in the thin direction of the motor body 12 (yoke 12a).

  In this seat motor 11, the planetary gear mechanism 22 is disposed adjacent to the worm gear mechanism 21, that is, the output gear 15 side which is one side in the axial direction with respect to the worm wheel 21b, and the reverse input cutoff clutch 24 is provided with the worm gear. The mechanism 21, that is, the worm wheel 21 b, is arranged adjacent to the other side in the axial direction, that is, the side opposite to the planetary gear mechanism 22.

  As a result, the planetary gear mechanism 22 and the reverse input cutoff clutch 24 are disposed in dead spaces within the thickness of the yoke 12a generated on one side and the other side in the axial direction of the worm gear mechanism 21, respectively. And the arrangement space of the reverse input cutoff clutch 24, that is, the thickness dimension of the seat motor 11 can be accommodated within the thickness dimension of the yoke 12a.

  Thus, in the seat motor 11, the planetary gear mechanism 22 is disposed on one side in the axial direction of the worm gear mechanism 21, and the reverse input cutoff clutch 24 is disposed on the other side. In addition to the planetary gear mechanism 22, the seat motor 11 including the reverse input cutoff clutch 24 can be reduced in size and thickness.

  Further, by reducing the size of the seat motor 11, the seat motor 11 can be arranged in a narrow space such as the inside of the seat, and the layout performance is improved.

  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, although the case where the present invention is applied to a seat motor is shown in the above-described embodiment, the present invention is not limited to this and may be applied to an electric motor for other purposes.

  Further, the reverse input cutoff clutch is not limited to the structure shown in the above embodiment, and has a function of transmitting the rotation of the worm gear mechanism to the planetary gear mechanism but not transmitting the rotation of the planetary gear mechanism to the worm gear mechanism. Any other structure may be used.

  Furthermore, in the above-described embodiment, the planetary gear mechanism is a so-called single pinion type. However, the planetary gear mechanism is not limited to this, and a so-called double pinion type planetary gear mechanism may be used.

  Further, according to the present invention, the reverse input cutoff clutch is provided in the power transmission path between the worm gear mechanism and the planetary gear mechanism. However, the present invention is not limited to this, and the reverse input cutoff clutch is provided between the armature shaft and the output shaft. You may make it provide in any part of the power transmission path | route between.

It is a perspective view which shows the seat motor which is one embodiment of this invention. It is sectional drawing which follows the AA line shown in FIG. FIG. 3 is a front view of the reverse input cutoff clutch shown in FIG. 2. It is an enlarged front view which expands and shows the principal part of the reverse input interruption | blocking clutch shown in FIG. (A), (b) is explanatory drawing which shows the action | operation state of a reverse input interruption | blocking clutch when a motor main body act | operates, respectively. (A), (b) is explanatory drawing which shows the operating state of a reverse input interruption | blocking clutch when a reverse input is added from an output shaft, respectively. It is explanatory drawing which shows arrangement | positioning of the planetary gear mechanism with respect to a worm gear mechanism, and a reverse input interruption | blocking clutch.

Explanation of symbols

11 Seat motor (electric motor)
12 motor body 12a yoke 12b armature shaft 13 speed reducer 13a gear case 13b housing portion 13c cover 13d fastening member 14 output shaft 15 output gear 16a bolt 16b nut 21 worm gear mechanism 21a worm 21b worm wheel 21c gear portion 21d engaging recess 22 planetary gear mechanism 22a Sun gear 22b Internal gear 22c Planetary gear 22d Carrier 22e Pin member 23 Intermediate shaft 24 Reverse input shut-off clutch 25 Outer ring 25a Outer lock surface 25b Flange portion 26 Inner ring 26a Boss portion 26b Mounting groove 26c Inner lock surface 27 Cage 27a Disc portion 27b Joint convex portion 27c Holding groove 27d Control surface 28 Roller 31 Holding spring

Claims (4)

A motor body with an armature shaft having a worm;
A worm wheel that meshes with the worm and decelerates and outputs the rotation of the armature shaft;
A gear case connected to the motor body and formed with an accommodating portion for accommodating the worm wheel;
A planetary gear mechanism that is housed in the housing portion and decelerates the rotation of the worm wheel to output from the output shaft;
Housed in the housing portion, provided in a power transmission path between the worm wheel and the planetary gear mechanism, transmits the rotation of the worm gear mechanism to the planetary gear mechanism, and does not transmit the rotation of the planetary gear mechanism to the worm gear mechanism An electric motor comprising a reverse input cutoff clutch. The electric motor according to claim 1,
The reverse input cutoff clutch is
An outer ring fixed to the gear case;
An inner ring that is arranged to rotate integrally with the planetary gear mechanism, and in which a plurality of mounting grooves are formed in the circumferential direction;
A cage that is arranged to rotate integrally with the worm wheel, is formed in an annular shape coaxial with the inner ring and the outer ring, and has a plurality of holding grooves formed in the circumferential direction;
A holding spring arranged between the outer ring and the inner ring, and arranged in the holding groove and the mounting groove;
A roller surrounded by the outer ring, the inner ring, the cage and the holding spring;
The retainer has a control surface for guiding the roller to the inner peripheral side at the end of the retaining groove.
The electric motor according to claim 1, wherein the inner ring has an inner lock surface formed such that a distance between an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring gradually increases as the distance toward the mounting groove increases.   3. The electric motor according to claim 1, wherein the electric motor is used as a seat motor for driving a vehicle seat in a vertical direction. A motor body with an armature shaft;
A worm gear mechanism that decelerates and outputs the rotation of the armature shaft;
A planetary gear mechanism that decelerates rotation of the worm gear mechanism and outputs it from an output shaft;
A reverse input blocking clutch provided in a power transmission path between the armature shaft and the output shaft, wherein the rotation of the armature shaft is transmitted to the output shaft, and the rotation of the output shaft is not transmitted to the armature shaft. An electric motor characterized by that.

Images