JP6175326B2 - motor - Google Patents

Description

  The present invention relates to a motor provided with a speed reduction mechanism used for a power window or the like.

  Some motors used as a drive source for raising and lowering the window glass of a vehicle power window include a lowering prevention mechanism that prevents the window glass from lowering when the motor is not operating.

  As one type of such a descent prevention mechanism, the brake plate is slidably contacted with the rotation shaft of the motor, and when the motor is not operating, the rotation of the rotation shaft is prevented by the frictional force between the rotation shaft and the brake plate, A configuration for preventing the window glass from descending has been proposed.

  Patent Document 1 discloses a motor in which a sliding member is brought into contact with a front end portion of a rotating shaft of a motor to generate a required friction and the rotation of the rotating shaft other than the driving force of the motor can be prevented by the friction. It is disclosed. The end of the rotating shaft is formed in a flat shape, and the sliding surface of the sliding member that abuts the rotating end is also formed in a flat shape so that the end of the rotating shaft and the sliding member are in surface contact. The required friction is ensured by sliding.

  When such a motor is used as a drive source for the power window, the rotation of the rotary shaft can be prevented when the motor is not operated, and the window glass can be prevented from descending.

JP 2001-69714 A

  In the motor disclosed in Patent Document 1, the end of the rotary shaft is in sliding contact with the sliding member by surface contact. For this reason, when a deflection occurs in the rotating shaft due to a load acting on the rotating shaft, the contact area between the end of the rotating shaft and the sliding member decreases, and the rotation of the rotating shaft due to the load can be reliably prevented. Disappear.

  An object of the present invention is to provide a motor that can prevent rotation of a rotating shaft due to a load even if the rotating shaft is bent.

Motor to achieve the above SL problem, a worm wheel in which a rotary shaft which is rotated based on the operation of the motor unit, a worm formed on the rotary shaft, meshing with the worm, rotated based on rotation of the rotary shaft And a braking member that slidably contacts the end portion of the rotating shaft and applies a braking force to the rotating shaft, the axial center portion of the rotating shaft protrudes from the end portion of the rotating shaft. A curved sliding surface is formed, the braking member is provided with an annular ridge capable of sliding along the sliding surface, and a recess surrounded by the ridge is filled with grease, The curvature of the central part of the sliding surface was made smaller than the peripheral part of the central part .

According to this configuration, even if the rotating shaft is bent, the contact area between the protrusion of the braking member and the sliding surface does not change, so that a stable braking force can be obtained.
Moreover, the recessed part enclosed with a protrusion functions as a grease reservoir.

According to this configuration, when the rotating shaft is not bent, the contact area between the ridge and the sliding surface is stabilized.
In the motor described above, a slope along the sliding surface is provided at the tip of the protrusion.

According to this configuration, the contact area between the protrusion and the sliding surface is stabilized.
In the motor, the diameter of the outer peripheral edge of the ridge is made smaller than the diameter of the sliding surface, and the ridge can be slid from the center portion to the peripheral portion of the sliding surface.

According to this configuration, when the rotation shaft is bent, even if the sliding surface is inclined with respect to the protrusion of the braking member, the contact area between the protrusion of the braking member and the sliding surface is stabilized .

In the above SL motor, based on the rotation of the output shaft of the worm wheel of the motor unit, comprising a regulator device for raising and lowering the window glass.

  According to this configuration, the window glass is prevented from descending when the motor unit is not operated.

  ADVANTAGE OF THE INVENTION According to this invention, even if bending occurs in the rotating shaft of a motor, rotation of the rotating shaft by a load can be prevented.

It is sectional drawing which shows the motor with a reduction mechanism of 1st Embodiment. It is the sectional view on the AA line in FIG. It is sectional drawing which shows the thrust bearing part before the thrust adjustment process in the same form. It is sectional drawing which shows the sliding contact state of the braking member and sliding surface in the form. It is sectional drawing which shows the sliding contact state of the braking member and sliding surface in the form. It is sectional drawing which shows another example of a braking member. It is sectional drawing which shows the motor with a reduction mechanism of 2nd Embodiment. It is sectional drawing of the front-end | tip part vicinity of the worm shaft in the same form. (A) is a top view of the braking member in the form, (b) is a side view of the braking member. It is sectional drawing of the base end part vicinity of the motor shaft in the form. It is sectional drawing of the joint in the form. It is sectional drawing of the front-end | tip part vicinity of the worm shaft in another example. It is sectional drawing of the base end part vicinity of the motor shaft in another example. It is sectional drawing of the base end part vicinity of the motor shaft in another example. It is sectional drawing of the joint in another example. It is sectional drawing of the joint in another example.

(First embodiment)
Hereinafter, a first embodiment of a motor will be described with reference to the drawings. The motor with a speed reduction mechanism shown in FIG. 1 includes a motor unit 1 and a speed reduction mechanism unit 2. As for the motor part 1, the magnet 4 is attached to the internal peripheral surface of the cylindrical yoke housing 3 which opened one end side.

  A rotor 6 having a rotating shaft 5 inside the magnet 4 is rotatably supported in the yoke housing 3. A bearing recess 7 is provided on the bottom surface of the yoke housing 3, and a metal bearing 8 is attached to the bearing recess 7.

  The rotating shaft 5 has a base end portion rotatably supported by the metal bearing 8 and a distal end portion extending in a speed reduction mechanism portion housing 9 attached to the opening of the yoke housing 3. . The distal end portion and the intermediate portion of the rotating shaft 5 are rotatably supported by the metal bearings 10 and 11 in the speed reduction mechanism portion housing 9. The speed reduction mechanism housing 9 is made of a thermoplastic resin.

  A brush device 24 is provided in the opening of the yoke housing 3. When an excitation current is supplied from the external control unit to the rotor 6 via the brush device 24, the rotor 6 and the rotating shaft 5 are rotated together. The base end portion of the rotary shaft 5 is rotated in contact with the inner surface of the bearing recess 7.

  The rotary shaft 5 is formed as a worm 12 between the metal bearings 10 and 11. In the speed reduction mechanism housing 9, the worm 12 is engaged with a worm wheel 13 that is rotatably supported in the speed reduction mechanism housing 9.

  The worm wheel 13 is rotated based on the rotation of the rotating shaft 5, and a regulator device (not shown) can be driven based on the rotation of the output shaft of the worm wheel 13.

Between the upper end portion of the rotating shaft 5 and the speed reduction mechanism housing 9, a friction sliding portion 22 that prevents the rotating shaft 5 from rotating when the motor unit 1 is not operated is provided.
As shown in FIG. 2, a curved sliding surface 14 is formed at the upper end of the rotating shaft 5 as the speed reducing mechanism portion 2 so that the axial center portion of the rotating shaft 5 is convex. The sliding surface 14 has a central portion with a smaller curvature than the peripheral portion, and is slightly flat.

  The speed reduction mechanism housing 9 is formed with a receiving portion 15 through which the rotating shaft 5 can be inserted, and a braking member 16 is disposed in a space 17 between the end of the receiving portion 15 and the sliding surface 14. Has been.

  The braking member 16 is formed in a disc shape with a synthetic resin, and an annular protrusion 18 that is concentric with the outer peripheral edge of the braking member 16 is formed on the lower surface facing the sliding surface 14. ing. The diameter of the outer peripheral edge of the protrusion 18 is smaller than the diameter of the sliding surface 14. The braking member 16 is accommodated in the space 17 in a state where the recess surrounded by the protrusion 18 is filled with grease 23 as a lubricant and the tip surface of the protrusion 18 is pressed against the sliding surface 14. ing.

  In order to assemble the rotary shaft 5 and the brake member 16 to the speed reduction mechanism housing 9, first, the brake member 16 is inserted into the housing portion 15 in a state where the recess 23 surrounded by the protrusion 18 is filled with grease 23, and then The rotating shaft 5 is inserted into the accommodating portion 15, and the sliding surface 14 is brought into contact with the tip surface of the protrusion 18. As shown in FIG. 3, in this state, a space 19 exists between the braking member 16 and the end of the accommodating portion 15.

  Then, when the adjustment jig 20 is pressed against the outer surface of the end portion of the housing portion 15 to apply ultrasonic vibration, the end portion of the housing portion 15 is overheated and softened, and the space 19 is crushed by the pressing force of the adjustment jig 20. The state shown in FIG. 2 is obtained. In this state, the protrusion 18 of the braking member 16 is pressed against the sliding surface 14, and a required braking force is generated with respect to the rotation of the rotating shaft 5 due to friction between the protrusion 18 and the sliding surface 14.

  The space 19 is filled with molten resin from the outside of the speed reduction mechanism housing 9 and solidified to adjust the position of the rotating shaft 5 in the thrust direction and the friction between the protrusion 18 and the sliding surface 14. Also good.

Next, the operation of the motor configured as described above will be described.
When the motor unit 1 is operated and the rotating shaft 5 is rotated, the rotation of the rotating shaft 5 is decelerated and transmitted from the worm 12 to the worm wheel 13. Then, the window regulator device is driven based on the rotation of the worm wheel 13, and the window glass is raised and lowered based on the forward / reverse rotation of the rotating shaft 5.

  In a state where the operation of the motor unit 1 is stopped, the rotation of the rotating shaft 5 is braked by the frictional force between the sliding surface 14 of the rotating shaft 5 and the braking member 16 pressed against the sliding surface 14. Therefore, the rotation of the rotating shaft 5 due to the load acting on the worm wheel 13 is prevented, and the window glass is prevented from descending.

  When a stronger rotating force acts on the worm wheel 13 in a state where the rotation of the rotating shaft 5 is blocked by the frictional force with the braking member 16, the arrow shown in FIG. 1 is applied to the meshing portion of the rotating shaft 5 with the worm wheel 13. A reaction force F in the direction acts to cause the rotating shaft 5 to bend in the same direction.

  Then, the sliding surface 14 of the rotating shaft 5 is inclined with respect to the braking member 16 from the state shown in FIG. 4 as shown in FIG. However, the contact area between the sliding surface 14 and the braking member 16 hardly changes due to the sliding surface 14 being a curved surface and the annular protrusion 18 of the braking member 16.

As a result, the frictional force between the protrusion 18 and the sliding surface 14 does not change, and the rotation of the rotating shaft 5 is prevented.
With the motor configured as described above, the following effects can be obtained.

  (1) The rotating shaft 5 due to a load acting on the worm wheel 13 when the motor unit 1 is not operated by the braking force obtained by pressing the braking member 16 against the sliding surface 14 formed at the end of the rotating shaft 5. Can be prevented. Therefore, when this motor with a speed reduction mechanism is used as a drive source for the power window device, it is possible to prevent the window glass from descending when the motor unit 1 is not in operation.

  (2) Since the annular ridge 18 of the braking member 16 is brought into contact with the curved sliding surface 14, even if the rotating shaft 5 is bent by the rotational force acting on the worm wheel 13, the ridge 18 is It is possible to reduce the change in the contact area while moving the sliding surface 14 relative to the sliding surface 14 so that the frictional force between the sliding surface 14 and the braking member 16 is not changed. Therefore, even if the load acting on the worm wheel 13 increases, the rotation of the rotating shaft 5 can be prevented and the window glass can be prevented from descending.

  (3) Since the curvature of the central portion of the sliding surface 14 is reduced, the load acting on the worm wheel 13 is small, and in a normal state in which the rotating shaft 5 is not bent, the protrusion 18 and the sliding surface 14 A contact area can be secured stably.

(4) The recess surrounded by the protrusion 18 of the braking member 16 can function as a grease reservoir.
You may implement the said embodiment in the following aspects.

  As shown in FIG. 6, the tip surface of the annular ridge 18 of the braking member 16 may be a slope 21 along the curved surface of the sliding surface 14 of the rotating shaft 5. With such a configuration, even if the sliding surface 14 is inclined with respect to the braking member 16 based on the deflection of the rotating shaft 5, the change in the contact area between the protrusion 18 of the braking member 16 and the sliding surface 14 is further reduced. In addition, a sufficient contact area between the protrusion 18 and the sliding surface 14 can be ensured.

(Second Embodiment)
Hereinafter, a second embodiment of the motor with a speed reduction mechanism will be described. In addition, the same code | symbol is attached | subjected to the structure same as the said 1st Embodiment, and the description is abbreviate | omitted.

  As shown in FIG. 7, in this embodiment, the motor shaft 31 of the rotor 6 and the worm shaft 32 supported by the speed reduction mechanism section housing 9 constitute a rotation shaft. Both the motor shaft 31 and the worm shaft 32 are made of a metal material.

  The base end of the motor shaft 31 is rotatably supported by a metal bearing 8 attached to the bearing recess 7 at the bottom of the yoke housing 3. Further, the motor shaft 31 is rotatably supported by a bearing 33 provided in the brush device 24 at a position near the tip portion thereof. The front end portion of the motor shaft 31 extends in the speed reduction mechanism housing 9.

  The worm shaft 32 is disposed coaxially with the motor shaft 31 inside the worm shaft housing portion 9a formed in the speed reduction mechanism housing 9 and is rotated by metal bearings 10 and 11 provided in the worm shaft housing portion 9a. Supported as possible. The proximal end coupling portion 32a of the worm shaft 32 is coupled to the distal end coupling portion 31a of the motor shaft 31 through a joint 34 provided in the speed reduction mechanism housing 9 so as to be integrally rotatable. A worm 12 that meshes with the worm wheel 13 is formed at a portion of the worm shaft 32 between the metal bearings 10 and 11.

  Between the tip of the worm shaft 32 (one end of the rotating shaft) and the speed reduction mechanism housing 9 is provided a friction sliding portion 22 that prevents the worm shaft 32 from rotating when the motor unit 1 is not operating. ing.

  As shown in FIG. 8, a curved sliding surface 35 is formed at the tip of the worm shaft 32 so that the axial center portion of the worm shaft 32 is convex. The sliding surface 35 has a central portion with a smaller curvature than the peripheral portion, and is somewhat flat.

  A braking member 41, a metal plate 42, and a resin member 43 are provided in the space between the end of the worm shaft housing portion 9 a and the sliding surface 35. The braking member 41 is in contact with the sliding surface 35 in the axial direction, and the metal plate 42 and the resin member 43 are disposed on the anti-sliding surface side of the braking member 41. The braking member 41 can be adjusted in its axial position and the degree of contact with the sliding surface 35 by an insert of the resin member 43. Further, the metal plate 42 prevents the resin member 43 from flowing into the braking member 41 side when the resin member 43 is inserted.

  The braking member 41 is formed of a synthetic resin in a disc shape, and an annular ridge 44 that is concentric with the outer peripheral edge of the braking member 41 is formed on the axial end surface facing the sliding surface 35. Has been. The diameter of the outer peripheral edge of the protrusion 44 is smaller than the diameter of the sliding surface 35, and the tip surface of the protrusion 44 is in pressure contact with the sliding surface 35.

  Further, as shown in FIGS. 8 and 9A and 9B, a through-hole 45 that penetrates the braking member 41 in the axial direction is formed in the central portion of the diameter of the braking member 41, so A communication groove 46 that communicates with the through hole 45 is formed on the end surface on the ridge side. The through hole 45 has one end in the axial direction communicating with the recess surrounded by the protrusion 44 and the other end in the axial direction communicating with the communication groove 46. The communication groove 46 is formed linearly along the radial direction so as to overlap the radial center (through hole 45) of the braking member 41, and both ends of the communication groove 46 are on the anti-projection side of the braking member 41. It extends to the outer peripheral edge of the end face of. The recesses surrounded by the protrusions 44 in the braking member 41 are filled with grease 23 as a lubricant.

Next, a support structure for the base end of the motor shaft 31 will be described.
As shown in FIG. 10, between the bottom portion 7a of the bearing recess 7 and the base end portion 31b of the motor shaft 31, a motor portion side braking member 51 made of a substantially cylindrical synthetic resin is accommodated. The motor-side braking member 51 has one axial end surface in contact with the bottom portion 7 a of the bearing recess 7 and the other axial end surface in contact with the base end portion 31 b of the motor shaft 31. The diameter of both end surfaces in the axial direction of the motor-side brake member 51 is set smaller than the diameter of the base end portion 31 b of the motor shaft 31. A grease hole 52 that penetrates the motor unit side braking member 51 in the axial direction is formed at the center of the diameter of the motor unit side braking member 51, and the grease hole 52 is filled with grease 53 as a lubricant. Has been. The motor part side braking member 51 is provided inside the metal bearing 8, and the outer diameter of the motor part side braking member 51 is set larger than the outer diameter of the base end part 31 b of the motor shaft 31.

  Further, the bottom 7 a of the bearing recess 7 is recessed in the axial direction, whereby the motor part-side braking member 51 is pressed against the base end part 31 b of the motor shaft 31. A required braking force is generated with respect to the rotation of the motor shaft 31 due to the friction between the motor shaft 31 and the motor portion side braking member 51.

Next, the joint 34 will be described.
As shown in FIG. 11, the joint 34 includes a resin portion 54 that is fixed to the tip connecting portion 31 a of the motor shaft 31 so as to be integrally rotatable. The resin portion 54 is formed with a substantially cylindrical fixing portion 55 that is fixed to the tip connecting portion 31 a of the motor shaft 31. The front end connecting portion 31a of the motor shaft 31 has a two-sided width shape, and is press-fitted and fixed in a press-fitting hole 55a that is formed through the central portion of the fixing portion 55 in the axial direction.

  On the worm shaft 32 side of the fixing portion 55 in the resin portion 54, a worm shaft side connecting portion 56 having a substantially cylindrical shape larger in diameter than the fixing portion 55 is integrally formed. A rubber member 57 is embedded in the worm shaft side connecting portion 56 by two-color molding. The rubber member 57 supports a base end connecting portion 32a having a flat shape of the worm shaft 32 inserted through the worm shaft side connecting portion 56 in the radial direction and the circumferential direction. The proximal end coupling portion 32 a of the worm shaft 32 is coupled to the worm shaft side coupling portion 56 so as to face the axial end surface 55 b (the worm shaft 32 side end surface) of the fixed portion 55.

  A resin plate 58 is embedded in the axial end surface of the proximal end coupling portion 32a of the worm shaft 32, and the resin plate 58 is configured so that a part thereof protrudes from the axial end surface of the proximal end coupling portion 32a. ing. The distal end surface of the distal end coupling portion 31 a of the motor shaft 31 is configured to be substantially flush with the axial end surface 55 b of the fixed portion 55 and is in contact with the resin plate 58 in the axial direction.

  In addition, a pair of grease grooves 55 c filled with grease 59 is formed on the inner surface of the press-fitting hole 55 a into which the tip connecting portion 31 a of the motor shaft 31 is press-fitted. Each grease groove 55c is formed at a position opposed to 180 degrees in the circumferential direction. The grease groove 55c extends to the axial end surface 55b of the fixed portion 55, and the grease 59 in the grease groove 55c is supplied to a contact portion between the tip connecting portion 31a and the resin plate 58. Yes.

Next, the operation of the motor of this embodiment will be described.
When the motor unit 1 is operated and the motor shaft 31 and the worm shaft 32 are rotated, the rotation of the worm shaft 32 is decelerated from the worm 12 to the worm wheel 13 and transmitted. Then, the window regulator device is driven based on the rotation of the worm wheel 13, and the window glass is raised and lowered based on the forward / reverse rotation of the motor shaft 31 and the worm shaft 32.

  In a state where the operation of the motor unit 1 is stopped, the rotation of the worm shaft 32 is braked by the frictional force between the sliding surface 35 of the worm shaft 32 and the braking member 41 pressed against the sliding surface 35. Accordingly, the rotation of the worm shaft 32 due to the load acting on the worm wheel 13 is prevented, and the window glass is prevented from descending.

  If a stronger rotational force acts on the worm wheel 13 in a state where the rotation of the worm shaft 32 is blocked by the frictional force with the braking member 41, a reaction force acts on the meshing portion of the worm shaft 32 with the worm wheel 13. As a result, the worm shaft 32 is bent. Then, the sliding surface 35 of the worm shaft 32 is inclined with respect to the braking member 41, but the sliding surface 35 is curved and the annular protrusion 44 of the braking member 41 causes the sliding surface 35 and the braking member 41 to be connected. The contact area hardly changes. As a result, as in the first embodiment, the frictional force between the protrusion 44 and the sliding surface 35 does not change, and the rotation of the worm shaft 32 is prevented.

  Further, during the operation of the motor unit 1, the grease 23 filled on the inner peripheral side of the protrusion 44 is supplied between the protrusion 44 and the sliding surface 35, and the braking member 41 (protrusion 44) and This prevents the friction of the worm shaft 32 from interfering with the rotation of the worm shaft 32, and the wear of the protrusion 44 is also suppressed.

  Here, in the present embodiment, the grease 23 that has flowed out from between the ridge 44 and the sliding surface 35 to the outer peripheral side of the ridge 44 passes through a gap between the outer peripheral surface of the braking member 41 and the inner surface of the housing 9. The brake member 41 is configured to go around the communication groove 46 on the back surface side (metal plate 42 side) of the braking member 41 and return from the communication groove 46 to the inner peripheral side of the protrusion 44 through the through hole 45. As described above, since the grease 23 circulates around the braking member 41, insufficient supply of the grease 23 to the sliding contact portion between the protrusion 44 and the sliding surface 35 is suppressed.

  In a state where the operation of the motor unit 1 is stopped, a required braking force is generated with respect to the rotation of the motor shaft 31 due to friction between the motor shaft 31 and the motor unit side braking member 51. On the other hand, during the operation of the motor unit 1, the grease 53 filled in the grease hole 52 is supplied to the sliding contact portion between the motor shaft 31 and the motor unit side braking member 51 to cause friction with the motor unit side braking member 51. Hinders rotation of the motor shaft 31 and wear of the motor-side braking member 51 is also suppressed.

  Further, due to the characteristics of the worm shaft 32 and the worm wheel 13, an axial load is generated when the worm shaft 32 is reversed. The load is received by the resin plate 58 of the proximal end coupling portion 32 a of the worm shaft 32. It has become. That is, the worm shaft 32 and the motor shaft 31, both of which are made of metal, are difficult to come into contact with each other, and generation of abnormal noise due to contact between these metal portions is suppressed.

  Furthermore, in the present embodiment, the grease 59 in the grease groove 55c formed in the press-fitting hole 55a of the fixing portion 55 is supplied to the contact portion between the motor shaft 31 (tip connection portion 31a) and the resin plate 58. It has become. Thereby, the wear of the resin plate 58 is suppressed, and the contact between the metal parts of the worm shaft 32 and the motor shaft 31 is more preferably suppressed. Further, since the grease groove 55c functions as a grease reservoir, insufficient grease between the motor shaft 31 and the worm shaft 32 is suppressed.

Next, characteristic effects of the present embodiment will be described.
(5) The brake member 41 is formed with a through hole 45 that communicates the communication groove 46 formed on the back surface (the end face on the side opposite to the worm shaft) of the brake member 41 and the recess surrounded by the protrusion 44. As a result, the grease 23 that has flowed out from the ridge 44 to the outer peripheral side circulates so as to return to the inside of the ridge 44 through the communication groove 46 and the through hole 45. Insufficient supply of grease 23 to the sliding contact portion can be suppressed.

  (6) The motor-side braking member 51 is pressed against the base end portion 31b of the motor shaft 31 in the axial direction. For this reason, when the operation of the motor unit 1 is stopped, a required braking force is generated with respect to the rotation of the motor shaft 31 due to friction between the motor shaft 31 and the motor unit side braking member 51. Further, since the grease hole 52 filled with the grease 53 is formed in the motor-side braking member 51, the grease 53 filled in the grease hole 52 becomes the motor shaft 31 and the motor when the motor part 1 is operated. It is supplied to the sliding contact part with the part-side braking member 51. Thereby, it is suppressed that the friction with the motor part side braking member 51 interferes with the rotation of the motor shaft 31, and the wear of the motor part side braking member 51 is also suppressed.

  (7) Since the base end coupling portion 32a of the worm shaft 32 is provided with the resin plate 58 that abuts the motor shaft 31 in the axial direction, the collision noise between the worm shaft 32 and the motor shaft 31 can be suppressed to a low level. it can.

  (8) The fixing portion 55 to which the motor shaft 31 is fixed is formed with a grease groove 55c filled with the grease 59 supplied to the contact portion between the motor shaft 31 and the resin plate 58. Thereby, the wear of the resin plate 58 is suppressed by the grease 59, and the contact between the metal parts of the worm shaft 32 and the motor shaft 31 can be more preferably suppressed. Further, since the grease groove 55c functions as a grease reservoir, insufficient grease between the motor shaft 31 and the worm shaft 32 (resin plate 58) can be suppressed.

In addition, you may implement the said embodiment in the following aspects.
In each of the above embodiments, the sliding surfaces 14 and 35 may be formed with a recess as a grease reservoir. FIG. 12 shows an example in which a recess 35a as a grease reservoir is formed on the sliding surface 35 of the second embodiment. The recess 35 a is formed in the center of the sliding surface 35 so as to be recessed in the axial direction. The recess 35a has a circular shape when viewed in the axial direction, and its diameter is set smaller than the inner diameter of the protrusion 44 of the braking member 41. That is, the space in the recess 35a is connected to the space in the ridge 44, and the grease 23 is accumulated in the recess 35a. According to such a structure, since the quantity of the grease 23 with which it fills can be increased, grease shortage can be suppressed.

  In the second embodiment, the grease hole 52 penetrates the motor part side braking member 51 in the axial direction. However, for example, as shown in FIG. 13, the motor shaft 31 in the motor part side braking member 51 is used. It is good also as a shape (shape which has not penetrated) recessed in the axial direction end surface of the side. According to such a structure, the rigidity of the motor part side braking member 51 can be improved.

  Further, as shown in FIG. 14, a recess 31 c as a grease reservoir may be formed in the base end portion 31 b of the motor shaft 31. In the example shown in FIG. 14, no grease pool is formed in the motor-side braking member 51, but the grease hole 52 as shown in the second embodiment or FIG. 13 may be added to this example. Good.

  In the second embodiment, as shown in FIG. 15, even if the shaft-side grease grooves 31 d are formed at positions corresponding to the pair of grease grooves 55 c of the fixing portion 55 in the tip connecting portion 31 a of the motor shaft 31. Good. According to such a structure, since the space filled with the grease 59 can be expanded and the amount of the grease 59 can be increased, insufficient grease can be suppressed.

  In the second embodiment, as shown in FIG. 16, a contact recess 32b as a grease reservoir is formed in the axial end surface of the base end connection portion 32a, and the tip connection of the motor shaft 31 is connected to the contact recess 32b. The portion 31a may be inserted so that the tip connecting portion 31a contacts the bottom surface of the contact recess 32b. According to such a configuration, although the metal portions of the worm shaft 32 and the motor shaft 31 are in contact with each other, the contact portions (the contact recess 32b and the tip connection portion 31a) are filled in the contact recess 32b. Since the grease 59 is supplied, wear of the contact portion can be suppressed, and occurrence of abnormal noise due to contact can be suppressed. Moreover, since the contact recessed part 32b functions as a grease reservoir, the lack of grease can be suppressed.

  In addition, in the example shown in FIG. 16, although the grease pool is not formed in the fixing | fixed part 55 of the joint 34 or the motor shaft 31, the grease groove | channel 55c of the said 2nd Embodiment with respect to this example, or FIG. Such a shaft-side grease groove 31d may be added.

  DESCRIPTION OF SYMBOLS 1 ... Motor part, 5 ... Rotating shaft, 12 ... Worm, 13 ... Worm wheel, 14 ... Sliding surface, 16 ... Braking member, 18 ... Projection, 21 ... Slope, 31 ... Motor shaft which comprises a rotating shaft, 32 ... Worm shaft constituting the rotating shaft, 35... Sliding surface, 41... Braking member, 44.

Claims (4)

A rotating shaft that is rotated based on the operation of the motor unit;
A worm formed on the rotating shaft;
A worm wheel that meshes with the worm and rotates based on rotation of the rotating shaft;
In a motor provided with a braking member that is in sliding contact with an end of the rotating shaft and applies a braking force to the rotating shaft,
A curved sliding surface in which an axial center portion of the rotating shaft is convex is formed at an end of the rotating shaft, and an annular protrusion that is slidable along the sliding surface on the braking member. Provided ,
Fill the recess surrounded by the ridge with grease,
A motor characterized in that a curvature of a central portion of the sliding surface is smaller than a peripheral portion of the central portion . The tip portion of the protrusion, the motor according to claim 1 Symbol mounting characterized by comprising a slope along the sliding surface. The diameter of the outer peripheral edge of the ridge, is made smaller than the diameter of the sliding surface, according to claim 1 or, characterized in that toward the periphery from the center of the sliding sliding surface and can slide said protrusion 2. The motor according to 2 . The motor according to any one of claims 1 to 3 , further comprising a regulator device that raises and lowers the window glass based on rotation of the output shaft of the worm wheel.