JPH01158249A - Reduction gear provided with oldham's coupling - Google Patents

Abstract

PURPOSE:To suppress noise and backlash by providing a planetary gear, a drive plate, a driven plate and an intermediate member placed between the planetary gear and an output shaft and transmitting drive force from the drive plate to the driven plate. CONSTITUTION:Driving force is transmitted from a motor to an eccentric shaft 12. A cycloid planetary gear mechanism 21 rotates while rolling corresponding to rotation of the eccentric shaft 12. An output shaft 24 having a flange is provided to the planetary gear side. An Oldham's coupling 22 has an intermediate disc member 26 through which rotation of a planetary gear 14 is transmitted to the output shaft 24. By such arrangement, noise and backlash are suppressed while the size and the weight of a reduction gear are reduced and reduction ratio is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a speed reduction device that mixes and integrates a cycloid planetary gear mechanism and an Oldham coupling.

[Prior art and problems]

If the motor rotates at low speed, the output will pulsate and a stable output cannot be obtained.Therefore, the motor has no choice but to rotate at high speed.In order to obtain high output (high torque) rotation from a high speed rotating motor. Therefore, a reduction gear is required.

The input shaft of the reduction gear is interlocked with the motor and rotates at high speed regardless of the size of the reduction ratio. The high-speed rotation of the input shaft is decelerated using a gear train in the speed reduction device and transmitted to the output shaft. The gear train is composed of a combination of a worm and a worm wheel, a combination of spur gears and bevel gears, and a planetary gear mechanism. However, in a gear train consisting of a combination of a worm and a worm wheel, the transmission efficiency □ is usually extremely low, so high output cannot be obtained.A planetary gear mechanism consists of an involute gear with an involute tooth profile.
Such planetary gear mechanisms, combinations of spur gears and bevel gears,
In the combination of a worm and a worm wheel, the number of teeth that mesh at the same time is about two. Since the transmitted torque is received by only two teeth, the tooth thickness and width must be large.Except for the combination of a worm and a worm wheel, the reduction ratio is determined by a pair of meshing gears ( In order to obtain a large reduction ratio (high reduction ratio), the driven gear must be made large. However, the size of the driven gear is usually limited, and the There is a limit to the deceleration by gears. Therefore, depending on the reduction ratio, a multi-stage structure is adopted in which a large number of gears are combined, and reduction gears with high reduction ratios tend to be larger. In addition, the transmission efficiency decreases with each combination of gears, so it is not possible to ensure high transmission efficiency in a multi-stage reduction gear.Therefore, in order to obtain high output, it is necessary to use it in conjunction with a high-output motor. .

Recently, there has been a strong demand for high output using micro motors (small motors). It is required to obtain an output of 100 Kg-cr1 or more by utilizing it. In this case, in order to obtain an output of 100 Kg-c+++ using a micromotor with an output of 200 g-c, it is necessary to rotate at a high speed of 12,000 rpm and reduce the speed at a high reduction ratio of about 1600. However, in the known speed reduction device, in order to obtain such a high reduction ratio, the speed reduction device must be considerably larger than the motor.

In addition to the torsional moment acting on the output shaft of the reduction gear, external forces such as axial load, bending moment, and shearing load are applied to the output shaft via the driven body.

Therefore, it is necessary to increase the rigidity by increasing the diameter of the output shaft and by thickening the other constituent members of the speed reduction device. In particular, a considerably large external force acts when driving the wipers of an automobile. Therefore, for such uses,
If a known speed reduction device is used, the speed reduction device must become larger due to the larger diameter of the output shaft and the thicker walls of other constituent members, and a smaller speed reduction device cannot be used.

Further, in the combination of a worm and a worm wheel, the combination of spur gears and bevel gears, and the planetary gear mechanism of known reduction gears, considerable noise is generated even if the gears are molded from plastic. In addition, because there are fewer teeth that mesh at the same time, the backlash is relatively large. Therefore, the known deceleration is required for precision equipment such as the latest audio equipment and video equipment, such as CrJ players, video cameras, word processors, CAD plotters, etc. When incorporating equipment, noise and backlash countermeasures are issues. Furthermore, although there is a particularly strong demand for miniaturization and weight reduction in this type of precision equipment, as mentioned above, known reduction gears are relatively large, and reduction gears are an obstacle to reducing the size and weight of precision equipment. There is.

[Purpose of the invention]

The present invention aims to provide a reduction gear device that suppresses noise and backlash, is small and lightweight, and has a high reduction ratio.

[Summary of the invention]

To achieve the above object, according to the present invention, a cycloidal planetary gear mechanism is used instead of a combination of a worm and a worm wheel, a combination of spur gears or bevel gears, or an (involute) planetary gear mechanism. Furthermore, an Oldham joint is built-in, and a cycloid planetary gear mechanism and an Oldham joint are integrally fixed to form a reduction gear (reduction gear with Oldham joint).

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in FIG. 1, in the reduction gear device 10 according to the present invention, the driving force of the motor is transmitted through an eccentric shaft 12 which also serves as an input shaft.
transmitted to. Planetary gear 14 is an eccentric shaft! It is arranged eccentrically with respect to the axis 11 by the same amount e in the same direction as 2, and the eccentric shaft is pivotally supported in the center hole 1B of the planetary gear. A cycloidal tooth-shaped external gear 18 is formed on the outer edge of the planetary gear 14. Further, a corresponding sun gear 20 having an internal gear 19 with a cycloidal tooth shape is arranged around the planetary gear 14, and a cycloidal planetary gear mechanism 21 is constituted by the meshing planetary gear and sun gear. Here, the planetary gear 14
is formed to have one fewer tooth than the sun gear 20. That is, if the number of teeth of the planetary gear 14 is 24 (N), the number of teeth of the sun gear 20 is 25 (N+1).

In the above configuration, when viewed from below in FIG.
When rotates clockwise (hereinafter, the rotation direction refers to the case viewed from below in FIG. 1), the planetary gear 14 meshes with the sun gear 20 due to the frictional force with the eccentric shaft. It follows the rotation of and revolves in the same direction. And since the number of teeth is one less than the sun gear 20, it is a planetary gear! 4 swings with respect to one rotation of the eccentric shaft 12.
It rotates counterclockwise by one tooth number, that is, 1/24 (1/N) rotation.

An Oldham joint 22 is interposed between the cycloidal planetary gear mechanism 21 and the output shaft 24 so as to detect only the rotation of the planetary gear 14 of the cycloidal planetary gear mechanism. The Oldham joint 22 has a disc-shaped intermediate member 2B, and is configured such that the rotation of the planetary gear 14 can be transmitted to the output shaft via this intermediate member. Since the planetary gear 14 serves as the driving plate and the output shaft 24 serves as the driven plate, the Oldham joint 22 is integrally fixed with the cycloidal planetary gear mechanism 21. That is, four elongated holes 28a to 28d separated by 90° from each other are drilled through the intermediate member 26, and the protrusion 1 is loosely fitted into the elongated holes 28a and 28c.
4a and 14c are provided on opposing surfaces of the planetary gear 14. Further, the output shaft 24 is formed in a flanged shape with a flange on the side of the planetary gear, and protrusions 24b and 24d that are loosely fitted into the elongated holes 2111b and 28d are provided on the opposing surfaces of the flange. Gear protrusions 14a, 14
c and the protrusions 24b and 24d of the output shaft are located perpendicular to each other, and the elongated holes 28a to 28d correspond to the protrusions 14a and 14c 2.
4b and 24d are formed to have a radial length that allows sliding in the radial direction. Oldham joint 22 shown
The shape of is just an example, and it goes without saying that the shape is not limited to this.

For example, protrusions 14a, 14c and protrusions 24b, 24
d may be a single protrusion, and corresponding elongated holes may be provided on the lower and upper surfaces of the intermediate member 26.Alternatively, even if a protrusion is provided on one surface of the intermediate member 2B and a elongated hole is provided on the other surface, the intermediate member 2B may be provided with a protrusion. Protrusions may be provided on each surface.

In the above configuration in which the Oldham joint 22 is interposed, when the planetary gear 14 rotates while swinging, the protrusions 14a and 14c of the planetary gear 14 are inserted into the elongated holes 26a and 26 of the intermediate member.
8c, the intermediate member 28 is pressed by the planetary gear 14 and integrally rotates counterclockwise. in this way,
The planetary gear 14 serves as a drive plate for the Oldham coupling. At this time, since the intermediate member 2B reciprocates in the radial direction while rotating, the rocking of the planetary gear 14 is caused by the protrusion 1
4a, 14c and the elongated holes 28a, 26c of the intermediate member. Therefore, the planetary gear I
4 rotates counterclockwise along with the intermediate member without swinging. Here, when the intermediate member 2B rotates, the protrusions 2 of the output shaft loosely fitted into the long holes 28b and 28d of the intermediate member
4b and 24d are pressed against the intermediate member, so the output shaft 24 also rotates together with the intermediate member. The output shaft 24 functions as a driven plate of the Oldham joint. As a result, the output shaft 24 is 11
It rotates in the opposite direction at a rotation speed of 24. In other words, the output shaft 24 rotates in reverse at the reduction ratio 24.

In the cycloid planetary gear mechanism 21, i half of the total number of teeth mesh at the same time, so there is little backlash and noise is less likely to occur.In addition, in the Oldham joint 22, the gap in the circumferential direction between the protrusion and the long hole is the same as that of the protrusion. It is sufficient to ensure sliding, and it can be set to the minimum. Therefore, the pack lash in one circumferential direction becomes zero, and the generation of noise is also suppressed. In this way, according to the reduction gear device 10 of the present invention, backlash and noise are reduced. Therefore, backlash,
Precision equipment that dislikes noise, such as CrJ players, bidets, word processors, CAD
This speed reducer 10 can be applied to the latest sound equipment such as plotters, precision equipment such as video equipment, and its range of applications is extremely wide.

Furthermore, since a large number of teeth mesh at the same time, the driving force borne by the negative teeth is small, allowing the tooth thickness and width to be reduced. Since the tooth thickness is small, a large number of teeth can be set even with a small diameter. Since the reduction ratio of the reduction gear is proportional to the number of teeth of the planetary gear 14, and the number of teeth of the planetary gear can be selected as appropriate, a high reduction ratio can be obtained by one step reduction. In addition, because the tooth width is small,
Can be molded thinly. Because it can be molded thinly and with a small diameter in this way, the N10 reduction gear can be made sufficiently smaller and lighter than known reduction gears, and is fully compatible with the demands for smaller and lighter precision equipment such as the latest audio equipment and video equipment. can.

Furthermore, since a large number of teeth engage simultaneously and there is no backlash, a high transmission efficiency of 8 oz can be easily obtained.

This transmission efficiency is high in both BOX (for worm and worm wheel gear trains) and 75% (for spur gears, etc. gear trains).With such high transmission efficiency, large output There is no need to use a motor
From this point of view, it also contributes to making precision equipment smaller and lighter.

In addition, in the basic configuration of a cycloid planetary gear mechanism in which a large number of output pins are loosely inserted into insertion holes, it is necessary to accurately set the positional relationship between the large number of output pins and the insertion holes in the radial and circumferential directions. , it is difficult to process with high precision.In contrast, Oldham joint 2 is used instead of the output pin and insertion hole.
In the structure of the present invention in which the Oldham joint 2 is interposed, accuracy in the radial direction is not required, and it is sufficient that the protrusions and long holes of the Oldham joint are perpendicular to each other in one circumferential direction. Therefore, the accuracy of the component parts can be easily achieved, and high-precision machining can be easily performed.Furthermore, in the basic configuration that combines output pins and insertion holes, there are many insertion holes into which the output pins are loosely fitted. Therefore, the structure of the present invention has a large number of void spaces and is inferior in strength, whereas in the configuration of the present invention, the area of the void spaces is also relatively small, ensuring sufficient strength and increasing the lifespan.

In addition, in this invention, although the Oldham coupling 22 is built-in, the planetary gear 14. Since the output shaft 24 serves as both the drive plate and the driven plate of the Oldham joint, the speed reducer 10 does not become large in size.

In the configuration of the present invention, a reduction gear device having a high reduction ratio of 1000 or more can be easily constructed by simply stacking the combination of the cycloid planetary gear mechanism 21 and Oldham coupling 22 as described above in the axial direction. and,
Even in this multi-stage deceleration configuration, the size and weight can be reduced without significantly increasing the size compared to known configurations.

FIGS. 2 and 3 show another embodiment of the present invention. In this embodiment, the reduction gear 110 is configured as a two-stage reduction, and a driven body is attached to the output shaft. Except for this, the basic configuration is the same as the embodiment shown in FIG. -1 is added to the constituent members of , and -2 is added to the constituent members of the second stage.

The speed reduction device 110 is housed in a housing 32 together with a motor (micro motor) 30, and a motor shaft 34 also serves as an input shaft of the speed reduction device. Eccentric shaft 11 of reduction gear
2-1 is fixed to the motor shaft 34 and is pivotally supported in the center hole 11B-1 of the planetary gear 114-1. The planetary gear 114-1 meshes with the sun gear 120-1,
The sun gear is fixed to the inner surface of the housing. A pair of elongated holes 12Ela-1, 128 cm1 are bored in the intermediate member 12B-1 of the Oldham joint, and a pair of protrusions 12
4b-1 and 124d-1 are formed on the upper surface of the intermediate member 90° opposite to the elongated hole. And long hole 128a-1
, 128cm1, a pair of projections 114a-1,
114 cm1 is the planetary gear 114-1, and the protrusion 124b-
1,124d-1, a pair of elongated holes 128b-1 that are loosely fitted
, 12[1d-1 are bored in the output shaft +24-1.

The secondary side eccentric shaft 112-2 is the primary side output shaft 124-1.
The driving force of the motor 3o is transmitted from the eccentric shaft on the secondary side to the output 124-2 on the secondary side through a similar configuration. - With the next deceleration, the motor shaft 34
The number of teeth of the planetary gear 114-1 - in the direction opposite to the rotation direction
The output of the reduction ratio proportional to N, ) is the output shaft 124 on the primary side.
-1. Since the secondary side is similarly decelerated, an output with a reduction ratio of N, X N2 is finally obtained on the secondary side output shaft 124-2 in the same direction as the motor shaft 34. Here, if N, -Nt=40, then
A high reduction ratio of 1800 can be obtained. In addition, output shaft 1
24-2 is pivotally supported by a post 33 at the upper end of the housing. Reference numeral 38 indicates a housing cover.As is clear from FIG. 2, the upper end of the output shaft 124-2 on the secondary side is
A driven body such as a swinging arm 40 is mounted on the upper end of the output shaft, and the swinging arm has a bearing 42 .
43, it is supported on the upper surface and side surface of the housing 32.

In the above configuration in which the swinging arm 40 is supported on the top and side surfaces of the housing 32, among the axial load, bending moment, shearing load, and torsion moment, the axial load, bending moment, and shearing load are transmitted through the swinging arm. It is transmitted to the housing, and the housing takes charge of the axial load, etc. Therefore,
The output shaft 124-2 only bears torsional moment, and in a configuration in which the housing 32 bears external forces such as axial load 1, bending moment, and shearing load, even if a large external force acts, the load on the output shaft 124-2 is small. Therefore, the output shaft 124-2 is not formed to have a very large diameter even though high mountain power can be obtained. Furthermore, since no external force is applied to the planetary gear and sun gear, which are the constituent members of the reduction gear, through the output shaft 124-2, there is no need to make the constituent members thicker. Can be configured to be small and lightweight.

In this way, reduction gear, 21tto, micro motor 30
By this combination, high output can be obtained under a high reduction ratio without increasing the diameter of the output shaft 124-2. Therefore, by combining the micromotor 30 with the smaller and lighter speed reduction device 110, it becomes possible to drive an electric door mirror, wiper, power window, top, etc. of an automobile using the micromotor 30.

In addition, with the configuration of this invention, a high transmission efficiency of 9 oz can be obtained with -stage deceleration, so even with two-stage deceleration, 8H
A transmission efficiency of (90×90) is still ensured.

FIG. 4 shows an application example in which a torque limiter 50 is attached to the speed reduction device 110 having the above configuration. The torque limiter 50 is
It is provided between a support body such as a support arm 54 screwed to the base 52 and the swing arm 40 which is a driven body. For example, the torque limiter 50 includes a friction plate 58, an upper bent piece 54a of the support arm, and a compression spring 58 disposed between the friction plates. Press onto the surface. Here, friction plate 5
8 is fitted to the output shaft 124-2 so as to be integrally rotatable. On the other hand, the output shaft 124-2 is loosely inserted into the hole 41 when the swing arm 40 is attached, and it goes without saying that the output shaft and the swing arm do not rotate together.

In such a configuration, the swing arm 4 is moved by the frictional force between the output shaft 124-2 and the friction plate 5B that rotates integrally with the output shaft 124-2.
The driving force is transmitted to zero, allowing limited torque transmission. F! The surfaces of the friction plate 56 and the swing arm 40 may be modified to increase the friction.

In the embodiment shown in FIG. 4, the output shaft 124-2 extends to the bent piece 54a at the upper end of the support arm, and this configuration prevents the compression spring 58 from falling off. Although the swinging arm 40 is directly supported on the top and side surfaces of the housing 32, bearings may be interposed therebetween.Although the constituent members of the speed reduction device are usually made of plastic, multi-stage speed reduction is possible. In such cases, since high torque is applied, it is preferable that the second and subsequent stage structural members be made of die-casting.

The above-mentioned embodiments are for illustrating the present invention, and are not intended to limit the present invention in any way, and any modifications, modifications, etc. made within the technical scope of the present invention are also included in the present invention. Needless to say.

For example, the eccentric shaft may be formed integrally with the input shaft or may be formed separately from the input shaft, and the bearings 42 and 43 may be omitted in FIG. 3.

〔Effect of the invention〕

As mentioned above, according to the present invention, since a large number of teeth mesh together at the same time, backlash is small and noise is less likely to occur.Also, even in Oldham joints, backlash is almost zero and noise generation is suppressed. . Therefore,
A speed reduction device can be obtained that can be applied to precision equipment such as the latest audio equipment and video equipment that dislike backlash and noise.

Additionally, since a large number of teeth mesh at the same time, the tooth thickness and width can be reduced, the number of teeth can be increased even with a small diameter, and a high reduction ratio can be obtained with one step reduction.

Also, since the tooth width is small, it can be molded thinly. Despite being able to obtain a high reduction ratio in this way, it can be molded thinly with a small diameter, so reduction gears can be made sufficiently small and lightweight, which is sufficient to meet the demands for miniaturization and weight reduction of precision equipment such as the latest audio equipment and video equipment. I can handle it.

Furthermore, since a high transmission efficiency of 90% can be easily obtained, high output can be obtained without using a high-output motor, and from this point of view as well, it contributes to the miniaturization and weight reduction of precision equipment.

In addition, by using the Oldham joint, the component parts can be processed with high precision, sufficient strength is ensured, and the service life can be extended.

Then, by simply stacking the combination of the cycloid planetary gear mechanism and the Oldham coupling in the axial direction, the reduction ratio is 1.
To easily construct a speed reduction device having a high reduction ratio of 000 or more without increasing the size.

[Brief explanation of the drawing]

FIG. 1 is a schematic exploded perspective view of a reduction gear device with an Oldham joint according to the present invention, and FIGS. FIG. 3 is a partially cutaway front view of the installed application. 10.110: Reduction gear with Oldham joint, 11: Axial center, 12.112: Eccentric shaft, 14,114: Planetary gear (
Oldham joint drive play)), lS: Center hole of planetary gear, 18: Cycloid external gear, 18: Cycloid internal gear, 20.120: Sun gear, 21: Cycloid planetary gear mechanism, 22: Oldham joint, 24, 124 : Output shaft with flange (Oldham joint driven play), 28:
Intermediate member of Oldham joint, 30: Micro motor, 32
: housing, 34: motor shaft, 40: swing arm (driven body), 42, 43: bearing, 50: torque limiter, 54: support arm (fixed body), 58: friction plate, 58: compression spring.

Claims (2)

[Claims] (1) (a) Eccentric shaft to which the driving force of the motor is transmitted;
b) planetary gears that have a cycloid tooth profile and mesh with each other;
(c) a cycloid planetary gear mechanism comprising a sun gear with one more tooth; the planetary gear has a central hole into which the eccentric shaft is fitted; and the planetary gear rotates while swinging in response to the rotation of the eccentric shaft; An output shaft having a flange on the side of the gear; (d) A planetary gear, a drive plate and a driven plate that also serve as the flange of the output shaft, and a planetary gear interposed between the output shaft and driven from the drive plate to the driven plate. An Oldham joint comprising: an intermediate member for transmitting force; and a reduction gear unit with an Oldham joint. (2) The cycloid planetary gear mechanism and Oldham coupling are housed in a housing, and the driven body attached to the output shaft extending from the housing is supported by the top and side surfaces of the housing, and external force acts on the driven body. The reduction gear unit with an Oldham joint according to claim 1, wherein the housing is configured to take charge of the following.