JP2001186716A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geared motor which can reduce vibration and noise among those integrating a drive motor and gear stream, particularly those utilizing a planetary gear mechanism. SOLUTION: A geared motor is provided with a first reduction part 14 for reducing the number of rotations of an output shaft 12 of a drive motor 13 and a second reduction part 15 for further reducing the number of rotations of the first reducing part 14. The first reducing part 14 includes a belt transfer device 18 for transferring rotations of a motor shaft to the driven shaft using a timing belt and the second reducing part 15 includes the planetary gear mechanism 27, 28. Since the second reducing part 15 includes the planetary gear mechanisms 27, 28, higher number of rotations can be maintained for a long period of time. Moreover, since the first reducing part 14 includes a belt transfer device 18, it absorbs intensive noise and vibration which have been generated when the timing belt 29 uses the planetary gear mechanisms 27, 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a geared motor in which a drive motor and a gear train are integrally combined.
In particular, the present invention relates to a first deceleration section which reduces the speed of an output shaft of a drive motor between two fixed axes to 1/30 as deceleration transmission, and a speed of an output shaft of the first deceleration section. The present invention relates to a geared motor having characteristics excellent in reduction of vibration, noise, and the like by applying the invention to a geared motor including a reduction mechanism including a second reduction section having a planetary gear mechanism for further reducing the speed.

[0002]

2. Description of the Related Art Geared motors used for electric equipment such as video, audio, and printers have been known. This geared motor combines a drive motor and a gear train integrally, reduces the rotation speed of the output shaft of the drive motor with the gear train to increase the drive torque of the motor shaft, and outputs the reduced rotation speed to the motor shaft. I have.

Conventionally, a geared motor using a planetary gear mechanism in a gear train has been known as this type of geared motor (see JP-A-8-33274). As shown in FIG. 4, the geared motor 1 includes a rotor 2 serving as an output shaft of a drive motor.
Is reduced by the three-stage planetary gear mechanisms 3a, 3b, 3c, and the reduced rotational speed is output to the motor shaft 9. Specifically, an external gear 4 as a sun gear is attached to the rotor 2,
An internal gear 6 serving as a sun gear is mounted inside a cylindrical case 5, and a plurality of planetary gears 7 are provided between the external gear 4 and the internal gear 6.
And the planetary gear 7 is rotatably supported by the carrier 8. When the rotor 2 rotates, the planetary gear 7 revolves while rotating, and the carrier 8 rotates. The rotation of the carrier 8 is transmitted to the next stage planetary gear mechanism 3b. The number of revolutions of the rotor 2 is sequentially reduced by the three-stage planetary gear mechanisms 3a, 3b, 3c, and finally, a predetermined reduction ratio is obtained to obtain the motor shaft 9
Is output to

[0004]

However, in the conventional geared motor 1 described above, the output shaft 2 of the drive motor is not provided.
Since all the gears are connected from the motor shaft 9 to the motor shaft 9, when the output shaft 2 is rotated, there is a problem that noise and vibration are generated at a meshing portion of the gear having a backlash. In particular, geared motors using planetary gear mechanisms
The structure in which the plurality of planetary gears revolve around the sun gear has increased the number of meshing portions of the gears, resulting in a problem that noise and vibration become severe.

Accordingly, an object of the present invention is to provide a geared motor in which a drive motor and a gear train are integrally combined, and in particular, a geared motor that can reduce vibration and noise in a geared motor using a planetary gear mechanism.

[0006]

In order to solve the above-mentioned problems, the present inventor has fixed the concept of reducing the speed by combining gears in a conventional geared motor.
A part of the gear train was replaced with a belt transmission, and a belt transmission was provided to absorb sound and vibration during the process from the output shaft to the motor shaft. That is, the invention according to claim 1 is a geared motor including a drive motor, a gear train that reduces the rotation speed of an output shaft of the drive motor, and a motor shaft that outputs the reduced rotation speed of the output shaft. The problem described above has been solved by a geared motor, wherein a belt transmission that transmits the rotation of a driving shaft to a driven shaft using a belt in a process from the output shaft to the motor shaft is provided.

According to the present invention, the belt transmission device not only transmits itself smoothly and quietly, but also absorbs noise and vibration generated by the engagement of the gear train with the belt. In addition, the belt transmission device absorbs a slight shift in the number of rotations of the gear train due to a meshing failure or the like due to expansion and contraction of the slack side and the tension side of the belt. Therefore, a geared motor that can significantly reduce vibration and noise can be obtained.

[0008] Here, the belt transmission device is constructed by attaching a pulley to a driving shaft and a driven shaft, and bridging a belt or a rope around the pulley. As the belt, a flat belt, a V-shaped belt, a toothed belt, a V-rib belt, or the like that does not cause slippage can be used.

According to a second aspect of the present invention, in the geared motor according to the first aspect, the gear train has a planetary gear mechanism.

When the geared motor has a planetary gear mechanism in the gear train, the number of meshing portions of the gear train increases, resulting in vibration and vibration.
Although the noise is often intense, the provision of the belt transmission absorbs the vibration and noise of the gear train into the belt for the reasons described above, and also absorbs the problem of meshing.

According to a third aspect of the present invention, in the geared motor according to the first or second aspect, the belt is constituted by a toothed belt, and the belt transmission reduces the rotation of the driving shaft and transmits the rotation to the driven shaft. It is characterized by.

According to the present invention, since the rotation is transmitted by the meshing of the teeth of the toothed belt, the rotation of the driving shaft can be reliably transmitted to the driven shaft. Further, since the speed is also reduced in the belt transmission, a geared motor having a large reduction ratio can be obtained.

According to a fourth aspect of the present invention, in the geared motor according to any one of the first to third aspects, the belt is stretched around the output shaft.

The effect of reducing vibration and noise can be obtained by providing a belt transmission device somewhere in the process from the output shaft to the motor shaft, but the effect is maximized when the belt transmission device is stretched over the output shaft.

According to a fifth aspect of the present invention, the rotational speed of the output shaft of the drive motor is reduced by 1/30 between two fixed axes.
A second reduction unit having a first reduction unit that reduces the speed within a range, and a planetary gear mechanism that further reduces the rotation speed of the output shaft of the first reduction unit.
And at least one of the plurality of two shafts to which the first reduction unit is fixed is connected by a toothed belt, and the other shafts are connected by gear transmission. The problem described above has been solved by a geared motor characterized in that it is configured.

According to a sixth aspect of the present invention, in the geared motor according to the fifth aspect, the first reduction portion is connected between the output shaft of the drive motor and the first rotation shaft by a toothed belt. The first rotation shaft and the output shaft of the first reduction unit are connected by gear transmission.

According to a seventh aspect of the present invention, in the geared motor according to the fifth or sixth aspect, when the two fixed shafts are connected to each other with a toothed belt, the reduction ratio is set to 1/2 or more. Features.

According to the fifth to seventh aspects of the present invention, the second
Has a planetary gear mechanism, a plurality of planetary gears can be arranged around the sun gear so as to transmit the load evenly, and a geared motor that can maintain high-speed rotation for a long period of time can be obtained. Also, since the first reduction unit has the belt transmission, it absorbs particularly intense noise and vibration generated when the belt uses the planetary gear mechanism,
A silent, low-vibration geared motor can be obtained. Note that the speed reduction of the first speed reduction unit is suppressed to within 1/30 in consideration of the mechanical strength of each part, and the reduction ratio of the belt transmission device is 1/2.
It is set above.

According to an eighth aspect of the present invention, in the geared motor according to any one of the fifth to seventh aspects, a casing for covering the first and second reduction portions, and a first reduction portion and a second reduction portion in the casing are provided. And a partition member for dividing the deceleration portion.

According to the present invention, since the first and second reduction portions are covered with the casing and are partitioned by the partition, vibration and noise can be further reduced.

According to a ninth aspect of the present invention, in the geared motor according to the eighth aspect, a protrusion is provided on the partition wall to prevent the belt from coming off the pulley.

According to the present invention, even if the belt is rotated at a high speed, the belt can be prevented from coming off the pulley.

[0023]

1 and 2 are exploded perspective views showing a geared motor according to an embodiment of the present invention. The geared motor includes a drive motor 13 and a drive motor 1.
A first reduction unit 14 that reduces the rotation speed of the output shaft 12
A second speed reducer 15 for further reducing the number of revolutions output by the first speed reducer 14, a first speed reducer 14, a second speed reducer 14,
And a motor shaft 11 for outputting the rotation speed reduced by 15; the rotation speed of the output shaft 12 is reduced and transmitted to the motor shaft 11 to increase the rotation torque of the motor shaft 11. The first reduction unit 14 and the second reduction unit 15 are arranged so as to be stacked in the axial direction of the drive motor 13. The casing has a substantially square bottom plate 16 fixed to the drive motor 13.
b, and a cover 16a attached to the motor shaft 11 side, and the first reduction unit 14 and the second reduction unit 15
Is covered. In the casing, a partition wall 17 that partitions the first reduction section 15 and the second reduction section 15 is provided.

The drive motor 13 is a known electric motor composed of an AC motor or a DC motor. Further, the first reduction unit 14 is configured by combining a belt electric device 18 and a gear train 19. First reduction unit 14
Is designed so that the deceleration of 1/30 or more is not performed in consideration of the mechanical strength of each part.

FIG. 3 is an exploded perspective view of the first reduction section 14. The belt motor 18 includes an output shaft 1 as a driving shaft.
2 is transmitted to the intermediate shaft 20 as a driven shaft. The output shaft 12 projects from a notch 16c opened in the bottom plate 16b. The intermediate shaft 20 is supported by the bottom plate 16b. Pulleys 21 and 22 with teeth are attached to the output shaft 12 and the intermediate shaft 20, respectively.
2, a timing belt 29 as a toothed belt is stretched. The reduction ratio of the belt transmission 18 is set to 1/2 or more (specifically, 1/3, 1/4, etc.).

The gear train 19 decelerates the rotation of the intermediate shaft 20 and outputs it to the second reduction unit 15. The gear train 19 has a small gear 23 integrally attached to the toothed pulley 22 of the intermediate shaft 20, and a small gear 23. The first reduction gear output gear 24 meshes with the gear 23 (see FIG. 1). This first reduction unit output gear 24
Is the first reduction unit output shaft 2 fixed to the center of the bottom plate 16b.
5 rotatably supported.

As shown in FIGS. 1 and 2, the bottom plate 16b and the partition 17 cover the first deceleration unit 14. Partition wall 1
7, a projection 17a is formed at a portion corresponding to the toothed pulley 22 of the intermediate shaft 20. A side wall 16d is provided on the bottom plate 16b.
Is formed on the side wall 16d.
The notch 16e is partially formed in accordance with. The side wall 16d is formed with a step 16f such that the cover 16a is fitted at a fixed position on the outer periphery of the side wall 16d. The step 16f hooks a rubber ring such as an O-ring on the step of the step 16f, and fits the cover 16a to eliminate a gap between the cover 16a and the bottom plate 16b, so that grease applied to the gap leaks out and leaks. Preventing. When the protrusion 17a and the notch 16e are aligned and the partition wall 17 is fixed to the upper surface of the side wall 16d, the protrusion 17a approaches the vicinity of the timing belt 29 and prevents the timing belt 29 from coming off the pulley 22.

The second speed reducer 15 for further reducing the number of revolutions output by the first speed reducer 14 is composed of upper and lower two-stage planetary gear mechanisms 27 and 28, and includes a cover 16a and a partition 17
Covered with. The reduction ratio in the second reduction unit 15 is 1/50 to
It is set to about 1/300.

As shown in FIGS. 2 and 3, of the two-stage planetary gear mechanisms 27 and 28, the first-stage planetary gear mechanism 27 includes, as shown in FIGS.
Three planetary gears 30 circumscribing with the planetary gears 3
The internal gear 31 includes an internal gear 31 as a sun gear in which the internal gear meshes internally, and a planetary gear frame 32 as a carrier that rotatably supports the planetary gear 30. The external gear 29 is integrally attached to the first reduction unit output gear 24 and protrudes from the center of the partition wall 17. The planetary gears 30 are rotatably supported by pins 33 projecting from the lower surface of the planetary gear frame 32, and are arranged at equal intervals in the circumferential direction, in this case, at 120 ° intervals. The internal gear 31 is fixed to the partition wall 17 so as not to rotate.

As shown in FIGS. 1 and 2, the second-stage planetary gear mechanism 28 includes an external gear 35 as a sun gear,
Four planetary gears 36 meshing with the external gear 35,
The planetary gear 36 includes an internal gear 37 as a sun gear in which the planetary gear 36 meshes internally, and a planetary gear frame 38 as a carrier that rotatably supports the planetary gear 36. The external gear 35 is fixed to the upper surface of the first-stage planetary gear frame 32. The planetary gears 36 are rotatably supported by pins projecting from the lower surface of the planetary gear frame 38, and are arranged at equal intervals in the circumferential direction, in this case, at 90 ° intervals. Internal gear 37
Is fixed to the internal gear 31 of the first stage planetary gear mechanism 28 so as not to rotate. The motor shaft 11 of the geared motor is fixed to the upper surface of the planetary gear frame 38.

Next, the operation of the geared motor will be described. When the output shaft 12 rotates, the intermediate shaft 20 rotates via the belt transmission 18. When the intermediate shaft 20 rotates, the first reduction unit output gear 24 that meshes with the small gear 23 of the intermediate shaft rotates. Then, the external gear 29 also rotates integrally with the first reduction unit output gear 24. The rotation of the external gear 29 is transmitted to the first-stage planetary gear mechanism 27 in the second reduction unit 15.
Specifically, since the external gear 29 rotates and the internal gear 31 is fixed, the planetary gear 30
Revolves while rotating. Due to the revolution of the planetary gear 30, the planetary gear frame 32 rotates. The rotation of the planetary gear frame 32 is transmitted to the second stage planetary gear mechanism 28. Specifically, the rotation of the planetary gear frame 32 causes the external gear 35 of the second-stage planetary gear mechanism 28 to rotate. Since the external gear 35 rotates and the internal gear 37 is fixed, the rotation of the external gear 35 causes the planetary gear 36 to revolve while rotating. The motor shaft 11 rotates by the revolution of the planetary gear 36.

As described above, the rotational speed of the output shaft 12 is reduced and transmitted to the motor shaft 11, so that the rotational torque of the motor shaft 11 can be increased. Also, since a plurality of planetary gears 30 and 36 are arranged around the external gears 29 and 35 at equal intervals in the circumferential direction so that the load can be evenly transmitted to the respective planetary gears 30 and 36, high speed is achieved. A geared motor that can maintain rotation for a long period of time is obtained. Further, since the first reduction unit 14 has the belt transmission 18, the belt transmission 18 itself transmits smoothly and quietly, and also noise and vibration generated by the meshing of the planetary gear mechanisms 27 and 28. Absorb. In addition, the belt transmission 18 absorbs a slight shift in the number of rotations of the planetary gear mechanisms 27 and 28 due to a meshing failure or the like due to expansion and contraction of the loosening side and the tension side of the timing belt 29. Therefore, a geared motor that can significantly reduce vibration and noise can be obtained.

[0033]

As described above, according to the present invention,
In a geared motor having a gear train, a belt transmission device is provided in the process from the output shaft to the motor shaft, so the belt transmission device itself transmits smoothly and quietly, and noise and vibration generated by meshing of the gear train Absorb even up to. Therefore, a geared motor that can significantly reduce vibration and noise can be obtained.

[0034]

EXAMPLE (Example 1) A vibration test was performed on the above-described geared motor according to the present invention when the motor was driven. In the vibration test, a geared motor was mounted on a frame, rotated while applying a load with a perma torque brake (Kosin Seiko Co., Ltd. HC6-1J), and the vibration of the frame at that time was taken out with an accelerometer (Showa Sokki Co., Ltd. 225). It was measured by a measuring instrument. Vibration measurement
With no load and with load (10kgf ・ cm, 16.5k
gf.cm, 20 kgf.cm). As a comparative example, vibration was measured under the same conditions for a conventional geared motor. The results are shown in FIG.

As is clear from FIG. 5, in the case of the comparative example, the vibration increases as the load increases, and
In the case of 0 kgf · cm, it becomes 0.08 G, whereas in the case of the embodiment, the vibration is constant at about 0.02 G regardless of the presence or absence of load, and it is possible to realize a geared motor with extremely quiet and low vibration. I understood.

(Example 2) The geared motor in Example 1 was tested for rotational unevenness during motor driving. Rotational encoder (Nikon RXB100
0) and take it out with a flat meter (Meguro Radio M
-615). The measurement of the rotation unevenness is performed in a state where no load is applied and a state where a load is applied (10 kgf · cm, 20 kgf · c
m, 30 kgf · cm). As a comparative example, a measurement test of rotation unevenness was performed on a conventional geared motor under the same conditions. The results are shown in FIG.

As is clear from FIG. 6, in the case of the comparative example, large rotation unevenness occurs as the load increases, whereas in the case of the embodiment, it is 0.1% or less regardless of the presence or absence of the load. It was found that a stable rotation was obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a geared motor according to an embodiment of the present invention as viewed obliquely from above.

FIG. 2 is an exploded perspective view of the geared motor according to one embodiment of the present invention as viewed obliquely from below.

FIG. 3 is an exploded perspective view showing a part of a first reduction gear and a planetary gear mechanism.

FIG. 4 is a sectional view showing a conventional geared motor.

FIG. 5 is a graph showing a result of a vibration test of the geared motor according to the present invention.

FIG. 6 is a graph showing a result of a rotation unevenness test of the geared motor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Motor shaft 12 Output shaft (drive shaft) 13 Drive motor 14 1st deceleration part 15 2nd deceleration part 16a Cover (casing) 16b Bottom plate (casing) 17 Partition 17a Projection 18 Belt transmission device 20 Intermediate shaft (Driving shaft) 22) Toothed pulley (pulley) 27, 28 Planetary gear mechanism (gear train) 29 Timing belt (toothed belt, belt)

Claims (9)

[Claims] 1. A geared motor comprising: a drive motor; a gear train for reducing the rotation speed of an output shaft of the drive motor; and a motor shaft for outputting the reduced rotation speed of the output shaft. A geared motor comprising a belt transmission that transmits rotation of a driving shaft to a driven shaft using a belt in a process of reaching a motor shaft. 2. The geared motor according to claim 1, wherein the gear train has a planetary gear mechanism. 3. The geared motor according to claim 1, wherein the belt is a toothed belt, and the belt transmission reduces the rotation of a driving shaft and transmits the rotation to a driven shaft. 4. The geared motor according to claim 1, wherein the belt is stretched over the output shaft, and the belt transmission uses the output shaft as the driving shaft. 5. A first reduction section for reducing the speed of an output shaft of a drive motor between two fixed axes to within 1/30 as a reduction transmission, and a rotation number of an output shaft of the first reduction section. A second reduction unit having a planetary gear mechanism that further reduces the speed of the first reduction unit, wherein the first reduction unit is connected to at least one of a plurality of two shafts fixed to each other with a toothed belt, A geared motor, wherein other shafts are connected by gear transmission. 6. The first reduction unit is connected between an output shaft of a drive motor and a first rotation shaft by a toothed belt, and the first rotation shaft and the output shaft of the first reduction unit are connected to each other. The geared motor according to claim 5, wherein the gears are connected by gear transmission. 7. The geared motor according to claim 5, wherein when the two fixed shafts are connected to each other with a toothed belt, a reduction ratio thereof is set to 1/2 or more. 8. A vehicle comprising: a casing that covers the first and second speed reducers; and a partition member that divides the first speed reducer and the second speed reducer inside the casing. Item 5
8. The geared motor according to any one of claims 1 to 7. 9. The geared motor according to claim 8, wherein a protrusion for preventing the belt from coming off the pulley is provided on the partition member.