JPS63285350A - Speed reduction gear - Google Patents

Abstract

PURPOSE:To raise transmitting efficiency of a speed reduction gear having its noise and back lash restrained, its size and weight reduced, and its reduction ratio increased by constituting a speed reduction gear of small transmitting torque with epicyclic gear trains each of which comprises a sun gear having cycloid tooth form and epicyclic gears. CONSTITUTION:A speed reduction gear 10 of small transmitting torque has a flange 12 which can be attached to a stationary body. And epicyclic gear trains 14, 54 have an eccentric shaft 28, sun gears 30, 70 and epicyclic gears 32, 72 and the eccentric shaft 28 is interlocked with a motor shaft 20 and serves as an input shaft of the epicyclic gear trains 14 and 54. The sun gears 30, 70 have cycloid tooth form with tooth number (n) on their inner peripheries, and the epicyclic gears 32, 72 meshed therewith have the same tooth of the tooth number (n-1) on their outer peripheries and the former gears are slidably fitted loosely around the eccentric shaft 28. And, plural output pins 38, 78 are formed on the side surfaces of the epicyclic gears 32, 72 on the respective concentric circles, and the output with reduced speed can be obtained from the sun gear 70. Accordingly, the constitution is simplified and can be reduced in its size and weight, speed reduction ratio is large, transmitting efficiency is high by use of cycloid tooth gears, and back-lash and noise can also be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a speed reduction device that utilizes a planetary gear train formed by meshing a cycloidal tooth-shaped sun gear and planetary gears.

[Prior art and its problems]

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

By the way, the input shaft of the reduction gear is rotated at high speed in conjunction with the output shaft (motor shaft) of the motor, and the high speed rotation of the input shaft is slowed down and transmitted to the output shaft using a gear train. . Generally, a gear train is composed of a combination of a worm and a worm wheel, or a combination of spur gears and bevel gears. However, in such a gear train, there is a limit to the speed reduction achieved by a pair of meshing gears, and a large speed reduction ratio cannot be ensured by one stage of speed reduction. Therefore, when a large reduction ratio is required, a reduction gear is constructed by combining a large number of gear trains. In addition, the output of the reduction gear is obtained from an output shaft, and this output shaft is arranged in alignment with the input shaft, and the input shaft,
The output shafts extend in opposite directions. Therefore, the length from the end of the input shaft to the end of the output shaft is considerable.

Therefore, known reduction gears tend to become larger, and even small reduction gears with a transmission torque of 10,000 g-cm or less have a considerable thickness and are difficult to reduce in size and weight. In a small speed reduction device, if the gears are made of plastic, the weight can be reduced. However, since the gear train consists of a combination of a worm and a worm wheel, or a combination of spur gears and bevel gears, considerable noise is generated and backlash is relatively large. Furthermore, in a (small) reduction gear with a reduction ratio of 25, only a low value of about 60% can be obtained with a combination of a worm and a worm wheel, and about 75% with a combination of spur gears, etc.; therefore, the desired value cannot be obtained. In order to ensure the output of , it is necessary to use a high output motor. However, is it possible to reduce the speed of a high-output motor due to transmission efficiency? If used in conjunction with a motor, the large-output motor becomes bulky, which hinders reduction in size and weight of the reduction gear.

Therefore, precision equipment such as the latest audio equipment, video equipment, etc., incorporating this type of (small) speed reduction device, such as floppy disk drives, CD players, video cameras, etc.
Noise countermeasures for word processors, CAD plotters, etc.

Countermeasures against backlash have become a problem. In particular, despite the strong demand for smaller and lighter precision equipment as mentioned above, known reduction gears with a transmission torque of 10,000 g-c or less are relatively large, and it is difficult to make precision equipment smaller and lighter. This has become a major obstacle. Further, as described above, from the viewpoint of transmission efficiency, if a high-output motor is used in conjunction with a reduction gear, it is not preferable because it impedes miniaturization and weight reduction of precision equipment and accelerates battery consumption.

[Purpose of the invention]

This invention suppresses the occurrence of noise and backlash, and also provides a reduction gear that is small, lightweight, has a large reduction ratio, and has high transmission efficiency, especially for a transmission torque of 1°, 000 g-am.
[Summary of the Invention] In order to achieve the above object, a transmission torque of 10,000g-
In a reduction gear of C11 or lower, the gear train is composed of a planetary gear train consisting of a sun gear and a planetary gear, each having a cycloidal tooth profile. Further, the reduction gear device includes seven flanges that can be attached to a fixed body, the flanges are formed with a plurality of support holes located on a concentric circle, and the motor is attached to the flanges.

The planetary gear train is formed with an eccentric shaft, a sun gear, and a planet gear. The eccentric shaft is interlocked with the output shaft (motor shaft) of the motor by fitting, adhesion, etc., and also serves as the input shaft of the planetary gear train. The sun gear is formed with a cycloid tooth profile having n teeth on its inner periphery. The idler #jI wheel is formed with a cycloid tooth profile having n-1 teeth on its outer periphery that meshes with the sun gear, and is slidably fitted loosely on the eccentric shaft. A plurality of concentric output bins are formed on the side surface of the planetary gear, and are slidably fitted and supported in the support hole of the flange. In such a configuration, in response to the rotation of the motor shaft, l
/N rotations of output is obtained from the sun gear.

Alternatively, the sun gear may be formed on the inner periphery of a central hole drilled in the flange; in this case, the planetary gear train requires an output member, and a plurality of concentric support holes are provided on the output member. drilled. In such a configuration, an output that is decelerated to 1/N rotation is obtained from the output member in response to the rotation of the motor shaft.

〔Example〕

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

As shown in FIGS. 1 and 2, the speed reduction device 1O according to the present invention includes a flange 12 and a planetary gear train 14 having a cycloidal tooth profile.

As can be clearly seen from FIG. 3 in addition to FIGS. 1 and 2, the flange 12 is configured so that it can be attached to a fixed body (not shown) such as a chassis, and in the embodiment, the flange 12 is configured so that it can be attached to a fixed body (not shown) such as a chassis. A pair of attachment holes IB are bored at the upper and lower ends to be inserted. A motor 18 is attached to one side of this flange 12, for example, the right side, and the output shaft of the motor (motor shaft)
20 extends to the left through a central hole 22 in the flange. Note that reference numeral 24 connects the motor 18 to the flange 1.
There are three screws to be attached to 2, and 26 indicates the insertion hole for each screw.

The planetary gear train 14 includes an eccentric shaft 28, a sun gear 30, and a planetary gear 32. And eccentric shaft 28
is an eccentric portion 28 that is eccentric by e from the axis 21 of the motor shaft.
a, and is connected to and interlocked with the motor shaft 20 by fitting, adhesion, etc. The sun gear 30 is loosely fitted onto the motor shaft 20, and in the embodiment is formed with a cycloid tooth profile having 18 teeth on its inner periphery. The planetary gear 32 that meshes with the sun gear 30 is formed with 15 cycloid teeth on its outer periphery, one tooth less than the sun gear, and slides on the eccentric portion 28a of the eccentric shaft on the left surface of the flange 12. It is loosely fitted. That is, the axis 33 of the planetary gear 32 is eccentric with respect to the axis 21 of the motor shaft in the same direction and by the same amount as the eccentric portion 28a of the eccentric shaft.

As can be seen from FIG.
It is perforated on the left side of 2. In the embodiment, the support hole 34
are formed in six pieces separated by 80 degrees, but the arrangement and number are not limited to the embodiment. The planetary gear 32 integrally has a plurality of output bins 38 on the right side, and the output bins are It is located on the concentric circle 40 of the axis 33 of the planetary gear, and is loosely fitted and supported in the support hole 34 of the flange so that it can come into sliding contact. The concentric circle 40 of the output bin has the same radius as the concentric circle 3B of the support hole, and the diameter of the output bin 38 is equal to 2 of the eccentric lie of the support hole 34.
It is formed smaller than the support hole by a factor of 2, that is, by 2e.

In such a configuration, when the motor 18 is started and the motor shaft 20 rotates at high speed, the eccentric shaft 28 rotates integrally with the motor shaft. The rotation of the eccentric shaft integrated with the motor shaft on the second day causes the planetary gears to swing and rotate due to the sliding friction between them and the planetary gears 32. However, in the above configuration in which the output bin 38, which is smaller by 2e, is slidably fitted and supported in the support hole 34, the output bin slides in the support hole, is pressed, and swings within the support hole. do. Such rocking of the output bin 38 within the support hole prevents rotation of the planetary gear 32. That is, the planetary gear 32 swings following the rotation of the eccentric shaft 28, but does not rotate.The swinging of the planetary gear 32 rotates the sun gear 30 that meshes with the planetary gear. And planetary gear 3
2 has one less life than the sun gear 30, so the eccentric shaft 2
For one rotation of 8, that is, one rotation of the motor shaft 20,
The sun gear rotates in the opposite direction with a speed reduction of 1/the number of teeth, that is, 1/16. In other words, the sun gear 30 is reversed with a reduction ratio of 1B. Thus, according to this invention,
The output of the reduction ratio equal to the number of teeth of the sun gear is
obtained from.

As described above, in the configuration in which the support hole 34 of the output bin 3B is not provided in the housing but is provided in the flange 12,
However, there is no need to provide a housing for the female gear train 14, and it can be omitted. Further, the motor 18 is attached to the flange 12, and the flange is configured to be attachable to a fixed body. Therefore, no special parts are required for mounting the motor or attaching it to the fixed body.In this way, the flange also serves as the housing, the mounting member for the motor, and the member for attaching it to the fixed body, so the number of parts is reduced. In addition to being reduced,
The speed reducer 10 can be made thinner and sufficiently smaller and lighter.

Further, in this invention, the motor shaft 20 also functions as the input shaft of the reduction gear M10, and the sun gear 30 functions as the output shaft, so that the output shaft can be omitted. In this configuration without an input shaft and an output shaft, the configuration is simplified and can be made significantly thinner, making it possible to reduce the size and weight.

In the embodiment, another planetary gear train 54 is further arranged radially outward of the planetary gear train 14 to ensure a large reduction ratio. This planetary gear train 54 is inward (first stage)
It is structurally the same as the planetary gear train 14 of
Its MI is indicated by the reference numeral 40 added to the corresponding component of
In the embodiment showing the i-forming member, as shown in FIGS. 1 and 2, the axis 31 is eccentric by E, and the sun gear 30 of the first stage planetary gear train 14 is aligned with the axis 21 of the output shaft. installed. That is, the inner periphery of the sun gear 30 on which the cycloid tooth profile is formed is coaxial with the motor shaft 21, but the outer periphery of the sun gear is eccentric by E. The snap ring 41 is attached to the left end of the motor shaft 20 to prevent the sun gear 70 and the like from falling off the motor shaft.In this way, the first stage sun gear 30 itself is eccentrically provided. In the configuration, the eccentric shaft of the second-stage planetary gear train 54 is omitted, thereby simplifying the configuration and reducing the number of parts. A planetary gear 72 of the second stage planetary gear train is slidably and loosely fitted into the sun gear 30 which also serves as an eccentric shaft, and like the planetary gear 32, a cycloid tooth shape with 15 teeth is formed on the outer periphery of the planetary gear 72. is formed.

Further, a support hole 7 in which an output detection gear (output gear) 43 is formed integrally with the sun gear 70 on the outer periphery of the sun gear 70.
4 are equiangularly drilled six times in the flange 12, and corresponding output pins 78 are provided on the right side of the planetary gear 72. Here, the support hole 74 is provided on a concentric circle 7B of the axis 21 of the motor shaft, and the output pin 78 is provided on a concentric circle 80 of the axis 31 of the sun gear, and the diameter of the output pin is equal to the eccentricity E of the planetary gear 72. Twice, that is, by 2E, support hole 7
Less than 4.

The sun gear 70 of the second-stage planetary gear train is loosely fitted into the boss of the sun gear 32 of the first-stage sun gear train, and the 16-tooth cyclotooth profile formed on the inner circumference of the sun gear 70 is connected to the planetary gear train. It meshes with the gear 72.

In the above configuration, the sun gear 3 of the inner planetary gear train 14
0 rotates as described above, the sliding friction between the sun gear 30, which also serves as an eccentric shaft, and the planetary gear 72
Try to oscillate and rotate. But output pin 7
8 swings within the support hole 74, the swing of the planetary gear 72 is converted into the swing of the output pin within the support hole, and the planetary gear merely swings and does not rotate. , planetary gear 7
2, the sun gear 7 meshes with the planetary gear 72.
0 is 1/number of teeth, that is, the speed is reduced to 1/18 and reversed. Here, the first stage sun gear 30 rotates in the opposite direction to the motor shaft 20 at a reduction ratio of 16, and the second stage sun gear 70 rotates in the opposite direction to the motor shaft 20.
is further reversed at a reduction ratio of 16, so the reduction ratio is 258.
A normal rotation of (18×1B) occurs in the sun gear 70 and is transmitted to the driven member via the output gear 43.

Thus, according to the invention, the planetary gear train 14.54
By stacking them in the radial direction, multi-stage reduction becomes possible and a large reduction ratio can be easily obtained.

In addition, in the configuration in which the planetary gear trains are stacked in the radial direction, multi-stage deceleration can be performed without increasing the thickness of the deceleration device 10 so much. For example, in a known reduction gear consisting of a two-stage gear train that combines a worm and a worm wheel, or spur gears, etc., even if the reduction ratio is 256 or less, the thickness is 105.
The limit is m. On the other hand, in the present invention, even at a reduction ratio of 256, the thickness is reduced by almost half to 5.51. The more stages there are, the more pronounced the effect of this invention of stacking planetary gear trains in the radial direction becomes, and the thinner the gear train becomes.

In the embodiment, the output gear 43 is provided on the sun gear 70 as an output member, but it may be formed on the outer periphery of the endless belt with a groove that can be engaged with, and a V pulley or a timing pulley may be used as the output member.

In this invention, the transmitted torque is 10.00 (Ig-cm
The following (small) reduction gears are targeted. Therefore,
Each component is small and no large frictional force acts on the bearing portion of the rotating member.Therefore, there is no need to provide separate bearings, the number of parts is drastically reduced, and the configuration is simplified.

In the example, the output bins 3rd and 7th are planetary gears 32.72
It is integrally molded to reduce the number of parts.
In the configuration of the embodiment, although a two-stage reduction is used, the independent parts of the reduction gear 10 are: (1) flange 12, (2) eccentric shaft 28,
■1st stage planetary gear 32 with output bin, ■1st stage sun gear 30, which also serves as the second stage eccentric shaft, ■2nd stage planetary gear 72 with output bin, ■2nd stage planetary gear 72, which also serves as the output member sun gear 7
These independent parts except for the snap rings 41, which are only seven snap rings 41 using commercially available products, can be easily molded by injection molding, for example.

Further, it can be easily formed by punching with a press.

As mentioned above, in the present invention, the cycloid gear 30.
A planetary gear train consisting of 32.70.72 and 14.54 is transmitted with a torque of 10. By applying it to the OOOg-c■ speed reduction device 10, compared to known speed reduction devices of this type,
It can be configured to be sufficiently thin and can be made smaller and lighter. Therefore, it can fully meet the demand for smaller and lighter precision equipment such as the latest audio equipment and video equipment.

In addition, in a cycloid gear, many teeth mesh together at the same time, so there is little backlash and noise is less likely to occur.
Electronic equipment that produces excessive noise, such as floppy disk drives, CI players, video cameras,
It can also be applied to word processors, CAD plotters, etc., and has an extremely wide range of applications.

Furthermore, according to the reduction gear device IO of the present invention, a high transmission efficiency of 90 gears can be easily obtained at the reduction ratio 1B. Therefore, there is no need to use a high-output motor, and from this point of view, it contributes to the miniaturization and weight reduction of precision equipment.

Another embodiment of the invention is shown in FIG. 3, and the components of this embodiment are designated by the reference numerals of the corresponding components of the embodiment shown in FIGS. 1 to 3 plus 100. That's it. In this reduction gear device 110, the first stage sun gear 130 is formed on the inner periphery of a central hole 48 formed in the flange 112.

In this manner, in the configuration in which the sun gear 132 is provided on the flange 112, an output member is required, and the output member 48 is loosely fitted to the eccentric portion 128a of the eccentric shaft. Output member 4
Similarly to the sun gear 30 of the first embodiment, the sun gear is formed with an inner periphery concentric with the axis 21 of the motor shaft and an outer periphery eccentric from the axis 21 by an amount E. It is loosely fitted into the non-eccentric part. In other words, the output member 48 also serves as the eccentric shaft of the second-stage planetary gear train 154. 6-support holes 134 are drilled conformally on the output member 4 and the planetary gear 1
Six output bins 138 protruding from the left side surface of 32 are slidably contacted and supported by corresponding support holes 134. and,
Since the motor shaft 120 of the reduction gear 110 is short, the eccentric shaft 128 fitted to the motor shaft extends to the left end, and instead of a snap ring, a washer 141 is attached to the eccentric shaft to prevent the sun gear 170 etc. from falling off. It is prevented. In addition, 2
The configuration of the planetary gear train 154 in the third stage is the same as the planetary gear train 54 of the first embodiment.

In the reduction gear device 110 having such a configuration, the motor 1
18 is activated and the motor shaft 120 rotates at high speed, the eccentric shaft 128 rotates together with the motor shaft. and,
Due to the sliding friction between the eccentric shaft 128 and the planetary gear 1
32 is connected to the motor shaft 1 while meshing with the sun gear 130.
While swinging in the opposite direction to 20, 1/number of teeth of the sun gear,
In other words, it rotates 1116 times.

As in the first embodiment, the support hole 1 of the output member 48
34, an output bin 178 having a smaller diameter by 2e is slidably inserted therein. Therefore, the swinging of the planetary gear 132 is absorbed by the gap between the support hole 134 and the output bin 138, and the output member 48 does not swing.

However, since the output pin 138 presses the support hole 134 with which it slides and rotates the output member 48, the planetary gear 1
It rotates integrally with 32. As a result, the output member 48 rotates in the opposite direction to the motor shaft 120 at a reduction ratio of 16.

The operation of this output member after the 4th day is the same as that in the reduction gear device 10, and the second stage sun gear 170 operates on the output member 4.
Therefore, the sun gear 170 rotates in the same direction (normal rotation) with a reduction ratio of 25B (18X 1B) with respect to the motor shaft 120.

In this configuration, the output member 48 in which the support hole 134 is formed
Is required. However, the sun gear 130 is connected to the flange 11.
2, the thickness corresponding to the thickness of the sun gear 130 can be saved. Also, in conventional configurations, the output shaft is aligned with the input shaft and extends in opposite directions. In contrast, in the configuration of the present invention, the output member 48 is not aligned with the motor shaft 20 that also serves as the input shaft, and can be arranged concentrically without extending in opposite directions, thereby increasing the thickness. I won't let you.

In this way, even if the output member 48 is provided, an increase in the total thickness is prevented, and the speed reducer 110 can be configured to have the same thickness as the speed reducer 10 described above. Of course, in this configuration as well, the housing of the gear train 114 can be omitted, and a reduced size and light reduction gear 110 with high transmission efficiency, low backlash and noise can be obtained. In addition, multi-stage deceleration can be easily achieved without increasing the thickness.

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, in the embodiment, the planetary gear trains are stacked in two stages, but they may be stacked in three or more stages.

〔Effect of the invention〕

As described above, according to the present invention, the flange also serves as a mounting member for the housing and the motor, and a member for attaching to the fixed body. Therefore, the number of parts is reduced, the configuration is simplified, the reduction gear device can be made thinner, and the reduction gear device can be sufficiently reduced in size and weight.

In addition, the output can be obtained from the sun gear or the output member,
These do not extend like the output shaft in known configurations, and the shaft-shaped output member (conventional output shaft) is omitted. Therefore, also from this point of view, it is possible to make the device thinner.

By stacking the convoys in the radial direction, multi-stage deceleration is possible without significantly increasing the thickness.

In this invention, the more stages there are, the more pronounced the effect of thinning becomes compared to a conventional configuration with the same reduction ratio.

Furthermore, since the gear train is formed using cycloid gears, a speed reduction device with high transmission efficiency and less backlash and noise can be obtained.

According to the present invention, a small and light speed reduction device is provided that satisfies the demand for reduction in size and weight in precision equipment such as floppy disk drives, CD players, video cameras, word processors, and CAD plotters.

[Brief explanation of the drawing]

1 is a longitudinal sectional view of the reduction gear according to the present invention; FIG. 2 is a cross sectional view of the reduction gear taken along the line -H in FIG. 1; FIG. 3 is a front view of the flange; The figure is a longitudinal sectional view of a speed reduction device according to another embodiment of the invention. 10.110: Reduction device, 12,112: Flange,
14,54,114.154: Planetary gear train, 18.11
8: Mounting hole, 18, 118: Motor, 20, 120:
Motor shaft, 21, 121: Motor shaft axis, 28.1
28: Eccentric shaft, 30,70,130.170: Sun gear, 32,72,132.172: Planetary gear, 34,7
4,134.174: Support hole, 3B, 40.7B, 80
: Concentric circle, 38, 78, 138.178: Output pin, 4
1: Snap ring, 43, 143: Output gear, 48
: Output member, 141: Stop washer.

Claims (4)

[Claims] (1) (a) Equipped with a plurality of support holes located on concentric circles,
(b) a flange to which a motor is attached and which can be attached to a fixed body; (b) an eccentric shaft linked to the output shaft of the motor attached to the flange; and a sun gear having a cycloid tooth profile with n teeth on its inner periphery. , each having a plurality of concentric output pins on the side surface, which are slidably fitted and supported in the support hole of the flange, and a cycloid tooth profile with the number of teeth n-1 meshing with the sun gear on the outer periphery,
a planetary gear loosely fitted in a slidable manner on an eccentric shaft; a planetary gear train comprising (c);
A speed reduction device whose transmission torque is 10,000 g-cm or less and whose output is reduced to N rotations and obtained from a sun gear. (2) Multiple sets of planetary gear trains are combined in the radial direction,
2. The speed reduction device according to claim 1, wherein the sun gear of the first stage planetary gear train is eccentrically arranged and also serves as the eccentric shaft of the second stage planetary gear train. (3) (a) A flange on which a motor is attached and can be attached to a fixed body; (b) an eccentric shaft linked to the output shaft of the motor; and an eccentric shaft formed on the inner periphery of a central hole drilled in the flange. A sun gear having a cycloid tooth profile with n teeth, an output member having a plurality of support holes located on a concentric circle, and a plurality of concentrically arranged sun gears that are loosely fitted and supported in a slidable manner in the support holes of the output member. It has an output pin on the side and a cycloid tooth profile with n-1 teeth on the outer periphery that meshes with the sun gear.
a planetary gear loosely fitted to the eccentric shaft so as to be slidable; a planetary gear train comprising (c);
A speed reduction device with a transmission torque of 10,000 g-cm or less, which provides an output reduced to /N rotations from an output member. (4) Multiple sets of planetary gear trains are combined in the radial direction, and one
4. The speed reduction device according to claim 3, wherein the output member of the second stage is arranged eccentrically and also serves as an eccentric shaft of the second stage planetary gear train.