JP3807703B2 - Motor with reduction mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a motor with a speed reduction mechanism that is used, for example, as a motor for an automobile power window.
[0002]
[Prior art]
Conventionally, as a motor with a speed reduction mechanism as described above, for example, a motor case, a motor shaft housed in the motor case and capable of rotating in the forward and reverse directions, and a speed reduction mechanism housed in a gear case connected to the opening of the motor case The speed reduction mechanism includes a worm formed on the tip end side protruding into the gear case of the motor shaft, a worm wheel meshing with the worm, and an external output shaft provided coaxially with the worm wheel. A hub connected to the worm wheel and assembled to the worm wheel while being engaged with the hub. The rotation of the worm wheel is transmitted to the external output shaft through the hub and can be compressed in the rotational direction between the worm wheel and the hub. It is equipped with a damper.
[0003]
This motor with a speed reduction mechanism is provided with a bearing that supports the vicinity of the worm of the motor shaft, and a contact resistance between the bearing and the motor shaft is set to be relatively large so that the load on the motor shaft in the direction opposite to the rotational direction is set. Therefore, when the motor with a speed reduction mechanism is used as, for example, a motor for a power window of an automobile, the window glass is prevented from being wrung out by an external force.
[0004]
[Problems to be solved by the invention]
However, in the above conventional motor with a speed reduction mechanism, for example, when the window glass is closed when used as a motor for a power window of an automobile, the operation of the motor with the speed reduction mechanism stops after the external output shaft is restrained. That is, since the motor shaft stops with a slight delay after the external output shaft is constrained, the damper compressed in the rotational direction between the hub stopped together with the external output shaft and the worm wheel stopped late. The restoring force of the worm wheel causes the worm wheel to bite the worm of the motor shaft. At this time, as described above, a load in the direction opposite to the rotation direction is applied to the motor shaft. Cannot be relieved, resulting in damage to the worm wheel or worm teeth. It has a problem that it can not be said that there is no possibility of put away, it has been conventional problem to solve this problem.
[0005]
OBJECT OF THE INVENTION
The present invention has been made paying attention to the above-described conventional problems. For example, when used as a motor for a power window of an automobile, the stress generated between the worm wheel and the worm when the window glass is closed is relieved. Therefore, an object of the present invention is to provide a motor with a speed reduction mechanism that can prevent the worm wheel or the tooth portion of the worm from being damaged.
[0006]
[Means for Solving the Problems]
The invention according to claim 1 of the present invention includes a motor shaft integrally rotating with a worm, a worm wheel that meshes with the worm of the motor shaft, a bearing that supports a portion near the worm of the motor shaft, In the motor with a speed reduction mechanism provided with an external output shaft provided at the shaft center of the worm wheel, and a damper that transmits the rotation of the worm wheel to the external output shaft and can be compressed in the rotation direction of the worm wheel. An inner ring that is rotatably mounted on the motor shaft and an outer ring that is rotatably mounted on the inner ring, and a contact resistance between the inner ring and the outer ring is determined between the motor shaft and the inner ring. It is set to be smaller than the contact resistance and regulates the rotation of the inner ring relative to the outer ring when the motor shaft rotates. The outer ring of the inner ring is restored by the restoring force of the damper applied to the motor shaft through the worm wheel and the worm when the rotation of the external output shaft accompanying the rotation of the motor shaft is restricted and the damper is compressed. The motor shaft with a speed reduction mechanism is provided with a return mechanism that allows rotation by a predetermined angle in the direction opposite to the rotation direction of the motor shaft. As a means to do.
[0007]
In the motor with a speed reduction mechanism according to claim 2 of the present invention, the return mechanism includes an inward engagement portion provided on the inner peripheral surface of the outer ring, and an inward direction of the outer ring provided on the outer peripheral surface of the inner ring. In the motor with a speed reduction mechanism according to claim 3 of the present invention, the motor is provided with an outwardly engaging portion in which the rotation of the inner ring with respect to the outer ring is restricted while being engaged with the engaging portion. Two inwardly engaging portions of the ring and two outwardly engaging portions of the inner ring are provided, both of which are arranged with an interval of approximately 180 °.
[0008]
[Effects of the Invention]
Since the motor with a speed reduction mechanism according to claims 1 and 2 of the present invention has the above-described configuration, for example, when used as a motor for a power window of an automobile, when the window glass is closed, that is, the motor shaft When the rotation of the external output shaft accompanying the rotation of the motor is restricted, the restoring force of the compressed damper is applied to the motor shaft via the worm wheel and worm. Therefore, the stress between the worm wheel and the worm is relieved, resulting in damage and durability of the worm wheel or worm teeth. The fall of the property will be avoided.
[0009]
And in the closed state of the wind glass, the return mechanism restricts the rotation of the inner ring with respect to the outer ring. Therefore, if the contact resistance between the motor shaft and the inner ring is set large, the window glass can be prevented from being plucked. Will be.
[0010]
Since the motor with the speed reduction mechanism according to claim 3 of the present invention has the above-described configuration, in the stage where the motor shaft rotates, the two inwardly engaging portions of the outer ring and the two inner rings of the return mechanism Since the outward engagement portions are simultaneously engaged with each other at an interval of about 180 °, the rotation of the inner ring with respect to the outer ring is reliably restricted, and the inward engagement portion and the outward engagement portion are The impact at the time of engagement is relieved and damage to the engaging portion is prevented.
[0011]
【Example】
Hereinafter, the present invention will be described with reference to the drawings.
[0012]
1 and 2 show an embodiment of a motor with a speed reduction mechanism according to the present invention. In this embodiment, the motor with a speed reduction mechanism according to the present invention is a motor for a power window of an automobile.
[0013]
As shown in FIG. 1, the motor 1 with a speed reduction mechanism is accommodated in the motor case 3 by positioning the armature 2 between magnets 4, 4 fitted with the armature 2 and fixed inside the motor case 3. The motor shaft 5 is capable of rotating in the forward and reverse directions, and a speed reduction mechanism 10 housed in a gear case 6 connected to the opening end of the motor case 3. The speed reduction mechanism 10 is provided in the gear case 6 of the motor shaft 5. A worm 11 formed on the protruding front end side, a worm wheel 12 meshing with the worm 11, a hub 13 provided coaxially with the worm wheel 12 and connected to the external output shaft 7, and engaged with the hub 13 In this state, the rotation of the worm wheel 12 is transmitted to the external output shaft 7 through the hub 13 and is rotated between the worm wheel 12 and the hub 13. It is provided with a damper 14 which is a compressible direction.
[0014]
One end (the left end of FIG. 1A) and the other end (the right end of FIG. 1A) of the motor shaft 5 are provided in a bearing 8 and a gear case 6 provided at the closed end of the motor case 3. Are supported by the bearings 9, and a portion near the worm 11 in the middle is supported by a bearing 20 provided in the gear case 6.
[0015]
As shown in FIG. 2, the bearing 20 that supports the vicinity of the worm 11 of the motor shaft 5 includes an inner ring 21 that is rotatably fitted to the motor shaft 5, and a ball 23 attached to the inner ring 21. The outer ring 22 is rotatably fitted, and the contact resistance between the inner ring 21 and the outer ring 22 is set smaller than the contact resistance between the motor shaft 5 and the inner ring 21. The contact resistance between the shaft 5 and the inner ring 21 is set to a size that can prevent the window glass (not shown) from being plucked by an external force.
[0016]
The bearing 20 restricts the rotation of the inner ring 21 relative to the outer ring 22 when the motor shaft 5 rotates and opens and closes the window glass, and the rotation of the external output shaft 7 accompanying the rotation of the motor shaft 5 is restricted. When the damper 14 is regulated and compressed between the worm wheel 12 and the hub 13, the inner ring 21 is moved to the motor shaft by the restoring force of the damper 14 applied to the motor shaft 5 via the worm wheel 12 and the worm 11. 5, a return mechanism 30 is provided for rotating by a predetermined angle in a direction opposite to the rotation direction of 5.
[0017]
The return mechanism 30 includes two inwardly engaging portions 31 provided on the inner peripheral surface of the outer ring 22 with an interval of approximately 180 °, and an outer peripheral surface of the inner ring 21 with an interval of approximately 180 °. Two outward engaging portions 32 provided in the outer ring, and in the stage of opening and closing the window glass, the inwardly engaging portions 31, 31 of the outer ring and the outward engaging portions 32 of the inner ring 21, 32, the rotation of the inner ring 21 relative to the outer ring 22 is restricted. On the other hand, when the rotation of the external output shaft 7 is restricted, the inner ring 21 is set to 0 by the restoring force of the damper 14. By rotating the motor shaft 5 in the direction opposite to the rotation direction of the motor shaft 5 within a range of the play 33 of from 180 ° to approximately 180 °, that is, the shape shown by the solid line in FIG. By rotating within the state shown in phantom from and so as to relieve stress between the worm wheel 12 and the worm 11.
[0018]
In the motor 1 with the speed reduction mechanism, for example, when the window glass is closed, the inward engagement portions 31 and 31 of the outer ring 22 and the outward engagement portions 32 and 32 of the inner ring 21 are engaged in the return mechanism 30. In addition, since the rotation of the inner ring 21 with respect to the outer ring 22 is restricted, the window glass is prevented from being plucked by the large contact resistance between the motor shaft 5 and the inner ring 21.
[0019]
Further, for example, when closing the window glass, if the rotation of the external output shaft 7 accompanying the rotation of the motor shaft 5 is restricted, the restoring force of the damper 14 compressed between the worm wheel 12 and the hub 13 thereby. Is applied to the motor shaft 5 via the worm wheel 12 and the worm 11, but the outward engagement portions 32, 32 of the return mechanism 30 in the bearing 20 are separated from the inward engagement portions 31, 31 by the restoring force of the damper 14. The inner ring 21 rotates away from the rotation direction of the motor shaft 5 within the range of play 33 from 0 ° to about 180 °, that is, the inner ring 21 is shown by a solid line in FIG. Since it rotates in the direction opposite to the rotation direction of the motor shaft 5 within the range indicated by the phantom line from the state shown, stress between the rotating worm wheel 12 and the worm 11 is relieved. Ri, and as a result, the reduction in damage and durability of the tooth portion of the worm wheel 12 or the worm 11 is avoided.
[0020]
FIG. 3 shows a bearing 40 employed to support the vicinity of the worm 11 of the motor shaft 5 in a motor with a speed reduction mechanism according to another embodiment of the present invention.
[0021]
As shown in FIG. 3, the bearing 40 includes an inner ring 41 that is rotatably fitted to the motor shaft 5 and an outer ring 42 that is rotatably fitted to the inner ring 41 via a ball bearing 43. The inner ring 43 a of the ball bearing 43 is fixed to the inner ring 41, and the outer ring 43 b is fixed to the outer ring 42.
[0022]
In this case, the contact resistance between the inner ring 41 and the outer ring 42, that is, the rotational resistance of the ball bearing 43 is set smaller than the contact resistance between the motor shaft 5 and the inner ring 41. The contact resistance with the inner ring 41 is set to a size that can prevent the window glass (not shown) from being squeezed out by an external force. Also in this bearing 40, the bearing of the motor 1 with a speed reduction mechanism according to the previous embodiment is used. 20, two inwardly engaging portions 31 provided on the inner peripheral surface of the outer ring 42 with a spacing of approximately 180 °, and provided on the outer peripheral surface of the inner ring 41 with a spacing of approximately 180 °. The return mechanism 30 having the two outward engagement portions 32 is provided.
[0023]
In the motor with a speed reduction mechanism provided with the bearing 40, the inward engagement portions 31 and 31 of the outer ring 42 and the outward engagement portions 32 and 32 of the inner ring 41 are engaged with each other at the stage of opening and closing the window glass. As a result, the rotation of the inner ring 41 with respect to the outer ring 42 is restricted. On the other hand, when the rotation of the external output shaft 7 is restricted, the inner ring 41 is moved from 0 ° to approximately 180 ° by the restoring force of the damper 14. The motor shaft 5 rotates in the direction opposite to the rotation direction of the motor shaft 5 within the range of the play 33, that is, the inner ring 41 is within the range indicated by the phantom line from the state indicated by the solid line in FIG. Therefore, the stress between the worm wheel 12 and the worm 11 is relieved.
[0024]
【The invention's effect】
As described above, according to the motor with a speed reduction mechanism according to claims 1 and 2 of the present invention, since it has the above-described configuration, for example, when used as a motor for a power window of an automobile, the window glass is blocked. When the restoring force of the damper is applied to the motor shaft via the worm wheel and worm by restricting the rotation of the external output shaft accompanying the rotation of the motor shaft, the inner ring is outered by the return mechanism , It is possible to relieve the stress between the worm wheel and the worm, so that the worm wheel or worm can be relieved. Can prevent damage to the teeth and decrease durability, and in addition, when the window glass is closed, It is possible to restrict rotation relative to the outer ring of the inner ring by a mechanism, extremely excellent effect that it is possible to prevent a pry-open the window glass is obtained by the contact resistance between the motor shaft and the inner ring.
[0025]
Since the motor with the speed reduction mechanism according to claim 3 of the present invention has the above-described configuration, in the stage where the motor shaft rotates, the two inwardly engaging portions of the outer ring and the two inner rings of the return mechanism Since the outward engagement portions can be simultaneously engaged with each other at an interval of approximately 180 °, the inner ring can be reliably restricted from rotating with respect to the outer ring. The impact when the outward engagement portion is engaged can be alleviated, and as a result, it is possible to obtain an extremely excellent effect that it is possible to prevent the engagement portion from being damaged.
[Brief description of the drawings]
FIG. 1 is a partially broken plan explanatory view (a) showing an embodiment of a motor with a speed reducing mechanism according to the present invention and a cross sectional explanatory view (b) at a speed reducing mechanism portion.
2 is a front explanatory view (a) and a cross-sectional explanatory view (b) of a bearing that supports a portion near a worm of a motor shaft in the motor with a speed reduction mechanism shown in FIG. 1. FIG.
FIGS. 3A and 3B are a front explanatory view (a) and a cross-sectional explanatory view (b) of a bearing that supports a portion near a worm of a motor shaft in a motor with a speed reduction mechanism according to another embodiment of the present invention.
[Explanation of symbols]
1 Motor with reduction mechanism 5 Motor shaft 7 External output shaft 11 Worm (deceleration mechanism)
12 Worm wheel (deceleration mechanism)
14 Damper (Deceleration mechanism)
20, 40 Bearing 21, 41 Inner ring 22, 42 Outer ring 30 Return mechanism 31 Inward engagement portion (return mechanism)
32 outward engagement part (return mechanism)

Claims (3)

A motor shaft integrally rotating with a worm, a worm wheel meshing with the worm of the motor shaft, a bearing supporting a portion near the worm of the motor shaft, and an external output provided at the shaft center of the worm wheel In a motor with a reduction mechanism that includes a shaft and a damper that transmits the rotation of the worm wheel to an external output shaft and is compressible in the rotation direction of the worm wheel, the bearing is rotatably fitted to the motor shaft An inner ring and an outer ring rotatably fitted to the inner ring, wherein a contact resistance between the inner ring and the outer ring is set smaller than a contact resistance between the motor shaft and the inner ring, and the motor shaft The rotation of the inner ring with respect to the outer ring is regulated at the stage of rotation of the inner ring, and the outer part accompanying the rotation of the motor shaft When the rotation of the force shaft is restricted and the damper is compressed, the restoring force of the damper applied to the motor shaft via the worm wheel and the worm reverses the rotation direction of the motor shaft relative to the outer ring of the inner ring. A motor with a speed reduction mechanism provided with a return mechanism that allows rotation by a predetermined angle in the direction. The return mechanism includes an inward engagement portion provided on the inner peripheral surface of the outer ring, and an outer portion of the inner ring provided in an outer peripheral surface of the inner ring and engaged with the inward engagement portion of the outer ring. The motor with a speed reduction mechanism according to claim 1, further comprising an outward engagement portion that is restricted from rotating with respect to the ring. The motor with a speed reduction mechanism according to claim 2, wherein two inwardly engaging portions of the outer ring and two outwardly engaging portions of the inner ring are provided, both of which are arranged at an interval of approximately 180 °.

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