JP2001186717A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a large size geared motor of which realization has been thought difficult in order to reduce number of rotations and load thereof when noise generated from the discrete geared motor is a problem. SOLUTION: Almost the entire surface of a motor 1 except for the rotating shaft and the area near the terminal is covered with an elastic support bodies 9a, 9b such as rubber or the like by being sandwiched. Thereby, the motor 1 does not come in contact with a case directly and vibration and noise generated from a discrete motor 1 are absorbed with the elastic support bodies 9a, 9b. Therefore, a lower noise geared motor can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a geared motor, and more particularly, to a geared motor that changes the rotational power of a motor by a gear mechanism.

[0002]

2. Description of the Related Art Conventionally, a geared motor has been used as a drive device used for electrically adjusting a lumbar support such as a waist rest portion of a vehicle seat or a headrest. The geared motor is mainly composed of a motor that generates rotational power and a plurality of gears, and generates a larger torque by sequentially shifting the rotational power generated by the motor to a low speed through the plurality of gears. Can be done.

[0003] In a geared motor, the rotational power generated on the motor shaft is firstly transmitted through a worm, which is a cylindrical screw gear having one or more threads, which is fixed to the motor shaft. Conveyed to. The worm wheel is a gear having a rotating shaft perpendicular to the motor shaft and having a tooth surface meshing with the worm. The rotational power given to the worm wheel in this way is
If necessary, the gears are sequentially decelerated via other gears, and the rotation output of the geared motor is obtained.

FIG. 4 is a schematic partial sectional view of a conventional geared motor. A conventional geared motor includes a motor 1, a worm 2, a worm wheel 3, and a gear 5.
a, 5b, 5c, 5d, a lower case 7, and an upper case 8. The gear 5d and the upper case 8 are not shown in FIG. The lower case 7 includes guide portions 10a, 10
b. The main body of the motor 1 is fixed to the lower case 7, the worm 2 is mounted around the motor shaft, and both ends of the motor shaft are rotatably supported by guide portions 10a and 10b, respectively. The worm wheel 3 and the gears 5a, 5b, 5c, 5d are rotatably supported by the lower case 7 and the upper case 8, respectively.

[0005] The operation of the conventional geared motor configured as described above will be described.

[0006] When the motor 1 is driven, rotational power is applied to the motor shaft. As the motor shaft rotates, the worm 2 mounted on the motor shaft rotates, and the worm 2
The worm wheel 3 arranged in mesh with the rotation of the worm wheel rotates. The gear 5 a is arranged coaxially with the worm wheel 3, and rotates in conjunction with the worm wheel 3. Each of the gears 5b to 5c is a superimposed gear, and the gear 5b is arranged so as to mesh with the gear 5a.
Are arranged so as to mesh with the gear 5b, and the gear 5d is arranged so as to mesh with the gear 5c.
With this arrangement, the rotational power of the motor 1 is sequentially reduced through a plurality of gears, and finally the gear 5
transmitted to d. With such a gear mechanism, the geared motor can obtain reduced rotational power.

In FIG. 4, when a certain load is applied to the worm wheel 3 when the worm 2 and the worm wheel 3 are engaged with each other, the worm 2 exerts a force in the direction in which the worm wheel 3 is pushed by the worm wheel 3. receive. Therefore, the motor shaft receives a clockwise moment on the drawing with the contact point with the motor body as a fulcrum. On the other hand, in this conventional geared motor, guide portions 10a and 10b are provided on the lower case 7, and each of them supports the motor shaft so as not to be displaced in a direction perpendicular to the axial direction. Therefore, the motor shaft receives a reaction force from the guide portion 10a to cancel the clockwise moment. In this manner, the proper engagement between the worm 2 and the worm wheel 3 is maintained.

When the above-described geared motor is used for adjusting a lumbar support or the like, it is particularly necessary to have low noise. The noise generated by the geared motor includes
There are mainly noise generated from the meshing portion of the gears and noise generated from the main body of the motor 1. The noise generated from the meshing portion of the gear can be reduced by increasing the accuracy of the gear, increasing the meshing ratio, or using a material having a high vibration damping rate for the gear, and reducing the noise from the main body of the motor 1. The generated noise can be reduced by reducing the rotation speed and the load of the motor 1.

[0009]

However, in order to reduce the rotational speed and load of the motor 1 and reduce the noise generated from the main body of the motor 1, it is necessary to change the shape of the motor 1 to a larger one. There was a problem that the change was not easy. Moreover, since the main body of the motor 1 is in direct contact with the lower case 7 and the upper case 8,
However, there is a problem that noise generated from the main body is easily transmitted to the outside of the geared motor.

Therefore, an object of the present invention is to provide a low noise geared motor without changing the motor shape.

[0011]

A first aspect of the present invention is a geared motor that generates the rotational power of a motor by changing the speed by a gear mechanism. The motor generates the rotational power and transmits the rotational power generated by the motor. A plurality of gears, an elastic support portion for supporting and fixing the motor, and an outer portion for housing the motor, the plurality of gears and the elastic support portion, and the motor is supported and fixed to the outer portion via the elastic support portion. It is characterized by the following.

A second invention is characterized in that, in the first invention, the elastic supporting portion covers the entire surface of the motor except for the vicinity of the rotating shaft and the terminals of the motor.

According to a third aspect of the present invention, in the first or second aspect, the elastic supporting portion comprises two members, each of which is fitted to the motor and abuts on the outer portion.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the plurality of gears mesh only with the worm mounted on the rotating shaft of the motor, the worm wheel meshed with the worm, and only the worm. And a small gear engaged with the worm wheel from the opposite direction with respect to the rotation axis of the worm.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic partial sectional view showing a configuration of a geared motor according to an embodiment of the present invention. FIG. 2 is a diagram showing the gear meshing relationship in the geared motor according to the embodiment of the present invention.

1 and 2, the geared motor includes a motor 1, a worm 2, and a worm wheel 3.
, A dummy gear 4, a worm stop 6a, 6b, gears 5a, 5b, 5c, 5d, a lower case 7, and an upper case 8.
And elastic supports 9a and 9b. The main body of the motor 1 is fixedly supported by the lower case 7 and the upper case 8 via elastic supports 9a and 9b, and the worm 2 is fixedly supported on the motor shaft by worm stops 6a and 6b. The worm wheel 3, the dummy gear 4, and the gears 5a, 5b, 5c, 5d
And it is rotatably supported by the upper case 8.

The following is an example of specific constituent members, shapes, and installation methods of the respective constituent elements when implementing the present embodiment.

The motor 1 is a DC brush motor having a rotary shaft diameter of 2 mm, a rotation speed of about 7,000 rpm, and an oval outer shell. The worm 2 is a worm made of polyacetal resin having a lead angle of 7 degrees, a module of 0.5 and an outer diameter of 5.56 mm. The worm wheel 3 is made of polyacetal resin. The worm stops 6a and 6b are made of brass and have a thickness of 1.2 mm. The dummy gear 4 is made of polyacetal resin, has eight teeth, and has an outer diameter of 5.4 mm. Lower case 7
The upper case 8 and the upper case 8 are both made of PBT (polybutylene terephthalate), and are fixed to each other with screws, so that the motor 1 covered with the elastic support 9 and a plurality of gear shafts are fixedly supported. The gear shaft of the dummy gear 4 is made of stainless steel and has a diameter of 2 mm. The elastic supports 9a and 9b are injection-molded articles such as polyurethane, and have a rubber hardness of hs7.
0, each of which has a notch in a portion corresponding to the vicinity of the rotation axis and the terminal of the motor 1, and the inner surface is
Is formed so that the outer surface thereof abuts against the inner flat surfaces of the lower case 7 and the upper case 8.

Hereinafter, the operation of the geared motor according to the embodiment of the present invention configured as described above will be described.

When the motor 1 is driven, rotational power is given to the motor shaft. As the motor shaft rotates, the worm 2 fixed to the motor shaft rotates, and the worm 2
The worm wheel 3 and the dummy gear 4 arranged so as to mesh with each other rotate accordingly. The gear 5 a is arranged coaxially with the worm wheel 3 and rotates in conjunction with the worm wheel 3. Gear 5b is gear 5a
The gear 5c is arranged in mesh with the gear 5b, and the gear 5d is arranged in mesh with the gear 5c. With this arrangement, the rotational power of the motor 1 is finally transmitted to the gear 5d, and the rotational power becomes the rotational output of the geared motor. In this way, the rotational speed of the motor, which was about 7,000 rpm, can be finally reduced to about 7 rpm. In addition,
The dummy gear 4 is arranged independently without meshing with another gear, and does not transmit the rotational power given by the worm 2 to the other gear.

FIG. 3 is a schematic sectional view of the geared motor and a perspective view showing the shape of the motor 1 and the elastic supports 9a and 9b. As shown in FIG. 3, the elastic supports 9 a and 9 b are formed so as to cover the entire surface of the motor 1 except for the vicinity of the rotating shaft and the terminals of the motor 1, and are fitted on the outer periphery of the motor 1.
The lower case 7 and the upper case 8 are supported and fixed so as to come into contact with the inner flat surfaces. As described above, the motor 1 is supported almost entirely by the elastic supports 9a and 9b, so that noise generated from the main body of the motor 1 is absorbed by the elastic supports 9a and 9b and the lower case 7 And the noise transmitted to the upper case 8 is reduced.

The elastic supports 9a and 9b are formed so as to fit into the outer periphery of the motor 1 and abut against the inner flat surfaces of the lower case 7 and the upper case 8, respectively. After being covered with the lower case 7 and the upper case 8 from above, the motor 1 is fixed by the elastic supports 9a and 9b without using special fixing means such as screwing. Support can be fixed.

Hereinafter, the effect of providing the dummy gear 4 will be described.

In FIG. 1, when a certain load is applied to the worm wheel 3 in the engagement between the worm 2 and the worm wheel 3, the worm 2 is moved from the worm wheel 3 to the worm wheel 3 with respect to the rotation center axis of the motor shaft. Subject to force in opposite direction. Therefore, the motor shaft receives a clockwise moment in FIG. 1 with the contact point with the motor body as a fulcrum. On the other hand, in the geared motor of the present embodiment, a dummy gear 4 is provided at a position opposite to the worm wheel 3 when viewed from the worm 2. Therefore, the motor shaft receives a reaction force from the dummy gear 4 via the worm 2 so as to cancel the clockwise moment. Thus, in the geared motor according to the present embodiment, it is possible to maintain an appropriate meshing state between the worm 2 and the worm wheel 3.

In the conventional geared motor shown in FIG.
Since the motor shaft is rotatably supported by the guide portions 10a and 10b provided in the lower case 7, the rotational vibration of the motor shaft is directly transmitted to the case, causing vibration and noise of the geared motor. As described above, by using the dummy gear 4, the motor shaft can be rotatably supported without directly touching the lower case 7 and the upper case 8. Therefore, the vibration of the motor shaft is transmitted to the lower case 7 via the dummy gear 4 and the gear shaft, so that the vibration and noise transmitted to the case are reduced.

As described above, according to the present embodiment, almost the entire body of the motor is covered with the elastic support, and the motor is fixedly supported on the case via the elastic support.
On the other hand, the motor shaft is supported via the worm wheel and the dummy gear without directly contacting the case. Therefore, neither the main body of the motor nor the motor shaft comes into contact with the case, so that vibration is not directly transmitted to the case, and vibration and noise generated from the main body of the motor are absorbed by the elastic support. Further, since the elastic support is fitted into the outer periphery of the motor and is in contact with the inner surface of the case, it is easy to assemble. Therefore,
It is possible to realize a geared motor that has low noise and can be easily assembled without changing the shape of the motor.

[0027]

According to the first aspect of the present invention, the motor is supported and fixed to the outer shell via the elastic support, so that the vibration and noise of the motor are absorbed and reduced by the elastic support, and then the outer shell is reduced. It is transmitted to. Therefore, it is possible to realize a geared motor with lower noise.

According to the second aspect of the present invention, since the elastic supporting portion covers almost the entire surface of the motor, vibration and noise transmitted from the motor to the outer portion are further reduced. Therefore, it is possible to realize a geared motor with lower noise.

According to the third aspect, the elastic support portion is constituted by two members formed such that each inner surface is fitted to the motor and each outer surface is in contact with the inner surface of the outer shell. By doing so, the motor is sandwiched by the elastic support parts,
Furthermore, by fixing and supporting it with the outer shell from above,
The motor can be easily supported and fixed by the elastic support without using special fixing means such as screwing, and the assembling becomes easy.

According to the fourth aspect of the present invention, the pinion is engaged with the worm from the opposite side of the worm wheel, so that the rotating shaft of the motor can be rotatably supported without directly touching the outer shell. Become. Therefore, it is possible to maintain an appropriate meshing state between the worm and the worm wheel, and further, since the rotational vibration of the rotating shaft of the motor is not directly transmitted to the outer shell, a geared motor with lower noise can be realized. It is possible.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view showing a configuration of a geared motor according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a meshing relationship of gears in the geared motor according to the embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view and a perspective view showing shapes of an elastic support and a motor in the embodiment of the present invention.

FIG. 4 is a schematic partial sectional view showing a configuration of a conventional geared motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motor 2 ... Worm 3 ... Worm wheel 4 ... Dummy gear 5a, 5b, 5c, 5d ... Gear 6a, 6b ... Warm stop 7 ... Lower case 8 ... Upper case 9a, 9b ... Elastic support

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H605 AA04 BB05 BB09 CC05 DD09 DD24 EA09 FF06 FF08 5H607 AA04 BB01 BB04 CC01 DD03 DD08 EE31 EE36 JJ05 JJ08 KK07 KK08

Claims (4)

[Claims] 1. A geared motor that generates a rotational power of a motor by changing the speed by a gear mechanism, comprising: a motor that generates a rotational power; a plurality of gears that transmit the rotational power generated by the motor; An elastic supporting portion for supporting and fixing; and an outer shell for accommodating the motor, the plurality of gears, and the elastic supporting portion, wherein the motor is supported and fixed to the outer shell via the elastic supporting portion. Characteristic geared motor. 2. The geared motor according to claim 1, wherein the elastic supporting portion covers an entire surface of the motor except for a vicinity of a rotating shaft and a terminal of the motor. 3. The elastic support portion comprises two members, each of which fits into the motor and abuts on the outer portion.
Geared motor according to the above. 4. The worm mounted on a rotation shaft of the motor, a worm wheel meshed with the worm, and a worm wheel meshed only with the worm, and the plurality of gears are arranged with respect to a rotation axis of the worm. The geared motor according to any one of claims 1 to 3, further comprising a worm wheel and a small gear that meshes from an opposite direction.