JP4320888B2 - Geared motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a geared motor, and more specifically, to a geared motor that generates a rotational power of a motor by a gear mechanism.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there is a geared motor as a driving device that is used when electrically adjusting a lumbar support such as a waist rest portion of a car 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 made.
[0003]
In the geared motor, the rotational power generated in the motor shaft is first transmitted to the worm wheel through a worm which is a cylindrical screw-shaped gear having one or more threads fixed to the motor shaft. . 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 applied to the worm wheel in this manner is sequentially decelerated via other gears as necessary, and becomes the rotational output of the geared motor.
[0004]
FIG. 4 is a partial cross-sectional schematic view of a conventional geared motor. The conventional geared motor includes a motor 1, a worm 2, a worm wheel 3, gears 5 a, 5 b, 5 c, 5 d, 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 has guide portions 10a and 10b. 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 the guide portions 10a and 10b, respectively. The worm wheel 3 and the gears 5a, 5b, 5c, and 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 around the motor shaft rotates, and the worm wheel 3 arranged in mesh with the worm 2 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 double gear, the gear 5b is arranged so as to mesh with the gear 5a, the gear 5c is arranged so as to mesh with the gear 5b, and the gear 5d is arranged with the gear 5c. It arrange | positions so that it may mesh | engage. By arranging in this way, the rotational power of the motor 1 is sequentially decelerated through a plurality of gears and finally transmitted to the gear 5d. With such a gear mechanism, the geared motor can obtain reduced rotational power.
[0007]
Here, in FIG. 4, when some load is applied to the worm wheel 3 in meshing between the worm 2 and the worm wheel 3, the worm 2 receives a force in the direction pushed by the worm wheel 3 from the worm wheel 3. Therefore, the motor shaft receives a clockwise moment in 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 in the lower case 7, and the motor shafts are supported so as not to be displaced in a direction perpendicular to the axial direction. Therefore, the motor shaft receives a reaction force that cancels the clockwise moment from the guide portion 10a. In this way, an appropriate meshing state between the worm 2 and the worm wheel 3 is maintained.
[0008]
When the above-mentioned geared motor is used for adjusting the lumbar support, it is particularly necessary to have low noise. The noise generated from the geared motor mainly includes noise generated from the meshing portion of the gear 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 rate, or using a material with a high vibration damping rate for the gear, The generated noise can be reduced by reducing the rotation speed and load of the motor 1.
[0009]
[Problems to be solved by the invention]
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, the shape of the motor 1 must be changed to a larger one, and the change is not easy. There was a problem. Moreover, since the main body of the motor 1 is in direct contact with the lower case 7 and the upper case 8, there is a problem that noise generated from the main body of the motor 1 is easily transmitted to the outside of the geared motor.
[0010]
Therefore, an object of the present invention is to provide a low-noise geared motor without changing the motor shape.
[0011]
[Means for Solving the Problems]
1st invention is a geared motor which changes and generates the rotational power of a motor with a gear mechanism, Comprising: The motor which generates rotational power, The several gearwheel which transmits the rotational power which the said motor generates, The said motor An elastic support portion that supports and fixes the motor, and an outer portion that houses 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 , The elastic support portion covers the entire surface of the motor except for the vicinity of the rotation shaft and terminals of the motor and is composed of two members that are vertically divided in the left-right direction. The two members are sandwiched by the motor from the left-right direction. respectively fitted as to abut respectively on the outer portion, the outer portion was horizontal split split vertically, consists lower case and upper case, before comprising the motor than two members After covering so as to sandwich the left and right direction by the elastic support portion, further characterized in that fixed by being sandwiched lower case and upper case thereon.
[0012]
In a second aspect based on the first aspect, the plurality of gears mesh with the worm mounted on the rotation shaft of the motor, the worm wheel meshing with the worm, the worm only, and the worm And a small gear meshing with the rotation axis of the worm wheel from the opposite direction .
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a partial cross-sectional schematic diagram showing a configuration of a geared motor according to an embodiment of the present invention. And FIG. 2 is a figure for demonstrating the meshing relationship of the gearwheel in the geared motor which concerns on embodiment of this invention.
[0016]
1 and 2, the geared motor includes a motor 1, a worm 2, a worm wheel 3, a dummy gear 4, worm stoppers 6a and 6b, gears 5a, 5b, 5c and 5d, and a lower case 7. The upper case 8 and elastic supports 9a and 9b are provided. 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, and 5d are rotatably supported by the lower case 7 and the upper case 8, respectively.
[0017]
Below, an example of the structural member of each specific component at the time of implementing this embodiment, a shape, and an installation method is shown.
[0018]
The motor 1 is a DC brush motor having a rotary shaft diameter of 2 mm, a rotational speed of about 7000 rpm, and an oval outer shape. The worm 2 is a polyacetal resin worm 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 stoppers 6a and 6b are made of brass and have a thickness of 1.2 mm. The dummy gear 4 is made of polyacetal resin and has 8 teeth and an outer diameter of 5.4 mm. Both the lower case 7 and the upper case 8 are made of PBT (polybutylene terephthalate), and both are fixed with screws, thereby fixing and supporting the motor 1 covered with the elastic support 9 and the plurality of gear shafts. The gear shaft of the dummy gear 4 is made of stainless steel, has a diameter of 2 mm, is press-fitted into the lower case, and is loosely installed in the upper case. The elastic supports 9a and 9b are injection-molded products such as polyurethane and have a rubber hardness of about hs70. Each of the elastic supports 9a and 9b has a notch in a portion corresponding to the vicinity of the rotating shaft and the terminal of the motor 1, and the inner surface is a motor. 1 is formed so that the outer surface is in contact with the inner flat surfaces of the lower case 7 and the upper case 8.
[0019]
Hereinafter, the operation of the geared motor according to the embodiment of the present invention configured as described above will be described.
[0020]
When the motor 1 is driven, rotational power is applied to the motor shaft. When the motor shaft rotates, the worm 2 fixed to the motor shaft rotates, and the worm wheel 3 and the dummy gear 4 arranged so as to mesh with the worm 2 rotate accordingly. The gear 5 a is arranged coaxially with the worm wheel 3 and rotates in conjunction with the worm wheel 3. The gear 5b is arranged to mesh with the gear 5a, the gear 5c is arranged to mesh with the gear 5b, and the gear 5d is arranged to mesh with the gear 5c. By arranging in this way, 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 7000 rpm, can be finally reduced to about 7 rpm. The dummy gear 4 is independently arranged without other gear meshing, it does not transmit the rotational power given from the worm 2 to the other gear.
[0021]
FIG. 3 is a schematic sectional view of the geared motor and a perspective view showing the shapes 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 terminals of the motor 1. 7 and the upper case 8 are supported and fixed so as to be in contact with the inner flat surfaces. Thus, since the motor 1 is supported by the elastic supports 9a and 9b so that the entire surface is covered, 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.
[0022]
The elastic supports 9a and 9b are formed so as to fit into the outer shell of the motor 1 and to contact the inner flat surfaces of the lower case 7 and the upper case 8, respectively, so that the motor 1 is sandwiched between the elastic supports 9a and 9b. Then, the motor 1 is supported and fixed by the elastic supports 9a and 9b without using any special fixing means such as screwing. be able to.
[0023]
Hereinafter, the effect by providing the dummy gear 4 is demonstrated.
[0024]
In FIG. 1, when any load is applied to the worm wheel 3 in meshing between the worm 2 and the worm wheel 3, the worm 2 is opposite to the worm wheel 3 from the worm wheel 3 with respect to the rotation center axis of the motor shaft. Receive power. 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, the geared motor of the present embodiment is provided with a dummy gear 4 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 through the worm 2 to eliminate the clockwise moment. Thus, in the geared motor of the present embodiment, it is possible to maintain an appropriate meshing state between the worm 2 and the worm wheel 3.
[0025]
In the conventional geared motor shown in FIG. 4, 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 and the vibration and noise of the geared motor. In this embodiment, as described above, the dummy gear 4 is used to support the motor shaft so that the motor shaft can rotate without directly touching the lower case 7 and the upper case 8 in the present embodiment. it can. Therefore, since the vibration of the motor shaft is transmitted to the lower case 7 via the dummy gear 4 and the gear shaft, the vibration and noise transmitted to the case are reduced.
[0026]
As described above, according to the present embodiment, almost the entire surface of the main 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 through the worm wheel and the dummy gear without directly contacting the case. Therefore, neither the motor main body nor the motor shaft is in contact with the case, so that vibration is not directly transmitted to the case, and vibration and noise generated from the motor main body are absorbed by the elastic support. Furthermore, since the elastic support body has a shape that fits into the outer shell of the motor and abuts against the inner surface of the case, it can be easily assembled. Therefore, it is possible to realize a geared motor that can be easily assembled with low noise without changing the shape of the motor.
[0027]
【The invention's effect】
According to the first invention, since the motor is supported and fixed to the outer portion via the elastic support portion, the vibration and noise of the motor are absorbed and reduced by the elastic support portion and then transmitted to the outer portion. Therefore, a lower noise geared motor can be realized. Further, since the elastic support portion covers almost the entire surface of the motor, vibration and noise transmitted from the motor to the outer portion are further reduced. Therefore, a lower noise geared motor can be realized. Furthermore, the elastic support portion is constituted by two members formed so that each inner side surface is fitted to the motor and each outer side surface is in contact with the inner side surface of the outer shell portion. It is possible to easily support and fix the motor with an elastic support member without using a special fixing means such as screwing, so that the assembly is easy. Become.
[0028]
According to the second invention, the small gear is engaged with the worm from the side opposite to the worm wheel, so that the rotation shaft of the motor can be rotatably supported without directly touching the outer portion. Accordingly, it is possible to maintain an appropriate meshing state between the worm and the worm wheel, and furthermore, since the rotational vibration of the rotating shaft of the motor is not directly transmitted to the outer portion, a lower noise geared motor can be realized. Is possible.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional schematic diagram showing the configuration of a geared motor according to an embodiment of the present invention.
FIG. 2 is a view for 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 the shape of an elastic support and a motor in an embodiment of the present invention.
FIG. 4 is a partial cross-sectional schematic diagram showing the 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 ... Worm stopper 7 ... Lower case 8 ... Upper case 9a, 9b ... Elastic support body

Claims (2)

A geared motor that generates a rotational power of a motor with a gear mechanism by changing the speed,
A motor that generates rotational power;
A plurality of gears for transmitting rotational power generated by the motor;
An elastic support for supporting and fixing the motor;
An outer portion that houses the motor, the plurality of gears, and the elastic support portion;
The motor is supported and fixed to the outer portion via the elastic support portion ,
The elastic support portion covers the entire surface of the motor except for the vicinity of the rotating shaft and terminals of the motor, and is composed of two members that are vertically divided in the left-right direction. respectively fitted so as to sandwich, each of the outer portions abut,
The outer portion is composed of a lower case and an upper case that are divided in the vertical direction. The outer case covers the motor so as to be sandwiched from the left and right by the elastic support portion formed of two members, and further from the upper case to the lower case. And a geared motor characterized by being sandwiched and fixed between upper cases . The plurality of gears are
A worm mounted on the rotating shaft of the motor;
A worm wheel meshing with the worm;
The geared motor according to claim 1, further comprising a small gear that meshes with only the worm and meshes with a rotation axis of the worm from a direction opposite to the worm wheel.

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