JPH0451694B2 - - Google Patents

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 a combination of a worm and a worm wheel, or
It consists of 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. Further, the output of the reduction gear device is obtained from an output shaft, and the output shaft is arranged in alignment with the input shaft, and the input shaft and the output shaft 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, making it difficult to reduce their size and weight. In such 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, it generates considerable noise and has relatively large bumps. Furthermore, in a (small) reduction gear with a reduction ratio of 25, the transmission efficiency is only as low as about 60% with a combination of a worm and a worm wheel, and about 75% with a combination of spur gears, etc. Therefore, in order to ensure the desired output, it is necessary to use a high output motor. However, if a high-output motor is used together with a reduction gear because of transmission efficiency, the large-output motor becomes bulky, which prevents the reduction in size and weight of the reduction gear.

Therefore, precision equipment such as the latest audio equipment and video equipment that incorporates this type of (small) speed reducer, such as floppy disk drives, CD players, video cameras, word processors, and CAD Noise countermeasures and backlash countermeasures have become a problem for printers and the like.
In particular, in the precision equipment mentioned above, despite the strong demand for smaller size and lighter weight, the transmission torque is 10,000 g-cm.
The following known reduction gears are relatively large and are a major obstacle to reducing the size and weight of precision equipment. 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]

The present invention provides a reduction gear that suppresses the generation of noise and bumps, is small, lightweight, has a large reduction ratio, and has high transmission efficiency.
The purpose is to provide a reduction gear of 10,000 g-cm or less.

[Summary of the invention]

To achieve the above purpose, the transmission torque is 10,000 g.
In a reduction gear of - cm or less, 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. In addition, the speed reducer is equipped with a flange that can be attached to a fixed body,
The flange is formed with a plurality of support holes located on a concentric circle, and the motor is attached to the flange.

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 planetary gear is formed to have 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 pins are formed on the side surface of the planetary gear, and are slidably fitted into the support hole of the flange.
Supported. In such a configuration, an output that is decelerated to 1/N rotation is obtained from the sun gear in response to the rotation of the motor shaft.

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, 1/N corresponds to the rotation of the motor shaft.
A rotationally reduced output is obtained from the output member.

〔Example〕

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

As shown in FIGS. 1 and 2, a speed reducer 10 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. A pair of mounting holes 16 are bored at the upper and lower ends. A motor 1 is attached to one side of this flange 12, for example, the right side.
8 is installed, and the motor output shaft (motor shaft) 20
extends to the left through the central hole 22 of the flange. Note that reference numeral 24 indicates three screws for mounting the motor 18 on the flange 12, and 26 indicates a through hole for the screws.

The planetary gear train 14 has an eccentric shaft 28 and a sun gear 3.
0 and a planetary gear 32. The eccentric shaft 28 is formed with an eccentric portion 28a eccentric by e from the axis 21 of the motor shaft, and is connected to the motor shaft 20 by fitting, adhesion, etc.
Linked. The sun gear 30 is loosely fitted onto the motor shaft 20, and in the embodiment is formed with a cycloid tooth profile having 16 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 less tooth than the sun gear, and slides onto 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. 3, a plurality of support holes 34
are perforated on the left side surface of the flange 12 equiangularly on a concentric circle 36 centered on the axis 21 . In the embodiment, six support holes 34 are formed at a distance of 60 degrees, but the arrangement and number are not limited to the embodiment. The planetary gear 32 integrally has a plurality of output pins 38 on the right side surface, and the output pins are located on a concentric circle 40 of the axis 33 of the planetary gear, and are slidably fitted and supported in the support hole 34 of the flange. has been done. The concentric circle 40 of the output pin has the same radius as the concentric circle 36 of the support hole, and the diameter of the output pin 38 is the same as the concentric circle 36 of the support hole 34.
It is formed smaller than the support hole by twice the amount of eccentricity e, 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 28, which is integral with the motor shaft, causes the planetary gear 32 to swing and rotate due to the sliding friction between the eccentric shaft 28 and the planetary gear 32. However, in the above configuration in which the output pin 38, which is smaller by 2e, is slidably fitted and supported in the support hole 34, the output pin slides in the support hole, is pressed, and swings within the support hole. do. Output pin 38 in such a support hole
The rotation of the planetary gear 32 is hindered by the rocking. That is, the planetary gear 32 swings following the rotation of the eccentric shaft 28, but does not rotate. This oscillation of the planetary gear 32 is caused by the rotation of the sun gear 30 meshing with the planetary gear.
Rotate. Since the number of teeth of the planetary gear 32 is one less than that of the sun gear 30, one of the teeth of the eccentric shaft 28 is
For each rotation, that is, one rotation of the motor shaft 20,
The sun gear rotates in the opposite direction with a speed reduction of 1/number of teeth, that is, 1/16. In other words, sun gear 30
is reversed with a reduction ratio of 16. Thus, according to the present invention, an output with a reduction ratio equal to the number of teeth of the sun gear can be obtained from the sun gear 30.

As mentioned above, the support hole 34 of the output pin 38 is
In the configuration in which the housing is not provided in the housing but is provided in the flange 12, there is no need to provide a housing for the planetary gear train 14, and the housing can be omitted. Also, flange 1
A motor 18 is attached to the flange 2, and the flange is configured to be attachable to a fixed body. Therefore, no special member is required for mounting the motor or attaching it to the fixed body. In this way, the flange serves as a mounting member for the housing, a motor, and a mounting member for the fixed body, so that the number of parts is reduced, and the speed reducer 10 can be made thinner and sufficiently reduced in size and weight.

Further, in the present invention, the motor shaft 20 also functions as the input shaft of the speed reduction device 10, 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 example, to ensure a large reduction ratio,
Another planetary gear train 54 is further arranged radially outwardly of the planetary gear train 14 . This planetary gear train 5
4 is structurally the same as the inner (first stage) planetary gear train 14, and its constituent members are indicated by reference numerals with the addition of the corresponding constituent member 40 of the planetary gear 14. In the embodiment, as shown in FIGS. 1 and 2, the axis 3
1 is eccentric by E, and the sun gear 30 of the first stage planetary gear train 14 is attached to the axis 21 of the output shaft. 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. A snap spring 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, 1
In the configuration in which the sun gear 30 itself in the second stage is provided eccentrically, 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, an output detection gear (output gear) 43 is formed on the outer periphery of the sun gear 70 and integrally with the sun gear.

Six support holes 74 are drilled equiangularly in the flange 12, and corresponding output pins 78 are connected to the planetary gear 72.
is located on the right side of the Here, the support hole 74
is provided on a concentric circle 76 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.
It is smaller than the support hole 74 by twice the eccentricity E of 2, that is, by 2E.

The sun gear 70 of the second stage planetary gear train is loosely fitted to the boss of the sun gear 32 of the first stage sun gear train,
A cycloid tooth profile with 16 teeth formed on the inner periphery of the sun gear 70 meshes with the planetary gear 72.

In the above configuration, when the sun gear 30 of the inner planetary gear train 14 rotates as described above, the sliding friction between the sun gear 30, which also serves as an eccentric shaft, and the planet gear 72 causes the planet gear 72 to sing and rotate. try to make it happen. However, the output pin 78 swings within the support hole 74, and the swing of the planetary gear 72 is converted into the swing of the output pin within the support hole, and the planetary gear simply swings and does not rotate. . And the planetary gear 72
Due to the oscillation, the sun gear 70 meshing with the planetary gear 72 is decelerated to 1/the number of teeth, that is, 1/16, and rotates in reverse. Here, the first stage sun gear 30 rotates in the opposite direction to the motor shaft 20 with a reduction ratio of 16, and the second stage sun gear 70 is further reversed with a reduction ratio of 16, so the reduction ratio is 256 ( 16×16) normal rotation is sun gear 7.
0 and is transmitted to the driven member via the output gear 43.

Thus, according to the present invention, the planetary gear train 1
4 and 54 in the radial direction, multi-stage reduction is 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 speed reduction device consisting of a two-stage gear train combining a worm and a worm wheel or a spur gear, the thickness is limited to 10 mm even if the speed reduction ratio is 256 or less.
In contrast, in this invention, even with a reduction ratio of 256,
The thickness is reduced by almost half to 5.5mm. 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 a groove capable of engaging an endless belt may be formed on the outer periphery, and a V-pulley or a timing pulley may be used as an output member.

The present invention is directed to a (small) speed reduction device with a transmission torque of 10,000 g-cm or less. 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 independently provide a bearing, the number of parts is drastically reduced, and the configuration is simplified.

In the embodiment, the output pins 38 and 78 are connected to the planetary gear 3.
2.72 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 the flange 12, the eccentric shaft 28, the planetary gear 32 with an output pin in the first stage, and the eccentric shaft in the second stage. 1st stage sun gear 30, which also serves as 2nd stage planetary gear 7 with output pin
2. A second stage sun gear 70 that also serves as an output member;
There are only 7 snap springs (41). These independent parts except for the snap ring 41, which is a commercially available product, can be easily molded by injection molding, for example. Further, it can be easily molded by punching with a press.

As described above, in the present invention, by applying the planetary gear train consisting of the cycloid gears 30, 32, 70, 72 to the reduction gear 10 with a transmission torque of 10,000 g-cm, Compared to a speed reduction device, it can be configured to be sufficiently thinner 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 less friction and less noise. Therefore, the reduction gear device 10 of the present invention
is a precision device that is extremely sensitive to noise, such as a floppy disk drive,
It can be applied to CD players, video cameras, word processors, CAD plotters, etc., and the range of applications is extremely wide.

Further, according to the reduction gear device 10 of the present invention, a transmission efficiency as high as 90% can be easily obtained at a reduction ratio of 16. Therefore, there is no need to use a high-output motor, and from this point of view, it also contributes to making precision equipment smaller and lighter.

Another embodiment of the invention is shown in FIG. Components of this embodiment will be designated by reference numerals with 100 added to the reference numerals of corresponding components of the above embodiment shown in FIGS. 1-3. This reduction gear 1
10, the first stage sun gear 130 is formed on the inner periphery of the central hole 46 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. Similarly to the sun gear 30 of the first embodiment, the output member 48 is formed to have 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, and the inner periphery is eccentric. It is loosely fitted to the non-eccentric part of the shaft. In other words, the output member 48 also serves as the eccentric shaft of the second-stage planetary gear train 154. 6
Six support holes 134 are equiangularly bored in the output member 48, and six output pins 138 extending from the left side surface of the planetary gear 132 are slidably contacted and supported by the corresponding support holes 134. 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 spring, a stop washer 141 is attached to the eccentric shaft to prevent the sun gear 170 etc. from falling off. It is prevented.
Note that the configuration of the second-stage planetary gear train 154 is similar to that of the first-stage planetary gear train 154.
This is equivalent to the planetary gear train 54 of the embodiment.

In the reduction gear device 110 having such a configuration,
When the motor 118 is started and the motor shaft 120 rotates at high speed, the eccentric shaft 128 rotates together with the motor shaft. Due to the sliding friction between the planetary gear 132 and the eccentric shaft 128, the planetary gear 132 and the sun gear 1
30 and swings in the opposite direction to the motor shaft 120, making 1/number of teeth of the sun gear, that is, 1/16 rotation.

As in the first embodiment, an output pin 178 having a smaller diameter by 2e is slidably inserted into the support hole 134 of the output member 48. Therefore, the rocking of the planetary gear 132 is absorbed by the gap between the support hole 134 and the output pin 138, and the output member 48
Do not shake. However, since the output pin 138 presses the support hole 134 with which it slides and rotates integrally with it, the output member 48 rotates integrally with the planetary gear 132. Ultimately, the output member 48 is connected to the motor shaft 120
, it rotates in the opposite direction with a reduction ratio of 16.

The operation after this output member 48 is performed by the reduction gear device 10.
The second stage sun gear 170
rotates in the opposite direction with respect to the output member 48 at a reduction ratio of 16. Therefore, the sun gear 170 rotates in the same direction (normal rotation) with respect to the motor shaft 120 at a reduction ratio of 256 (16×16).

This configuration requires the output member 48 in which the support hole 134 is formed. However, the sun gear 130
is provided on the flange 112, so that 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 reduction gear 11
0 can be configured to have a thickness equivalent to that of the speed reduction device 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 bumpiness 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.

[Effects of the Invention] As described above, according to the present invention, the flange serves as the housing, the mounting member for the motor, and the mounting member for the fixed body. Therefore, the number of parts is reduced and the configuration is simplified, so the reduction gear device can be made thinner and sufficiently smaller and lighter.

Also, the output is obtained from the sun gear or output member, which does not extend like the output shaft in known configurations, and the axial 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 gear trains in the radial direction, multi-stage reduction is possible without significantly increasing the thickness.
In this invention, the more stages there are, the more
Compared to a conventional structure with the same reduction ratio, the effect of reducing the thickness is significant.

Furthermore, since the gear train is formed using cycloid gears, a speed reduction device that has high transmission efficiency and is less likely to cause bumps and noises can be obtained.

According to the present invention, there is provided a small and lightweight speed reducer that satisfies the need for smaller and lighter precision equipment such as floppy disk drives, CD players, video cameras, word processors, and CDA plotters. .

[Brief explanation of drawings]

FIG. 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 along the line - in FIG. 1, FIG. 3 is a front view of the flange, and FIG. FIG. 2 is a longitudinal cross-sectional view of a speed reduction device according to another embodiment of the present invention. 10,110...Reduction gear, 12,112...
Flange, 14, 54, 114, 154... Planetary gear train, 16, 116... Mounting hole, 18, 11
8...Motor, 20, 120...Motor shaft, 2
1,121...Axis of motor shaft, 28,128...
...Eccentric shaft, 30,70,130,170...Sun gear, 32,72,132,172...Planet gear, 34,74,134,174...Support hole, 3
6, 40, 76, 80...concentric circles, 38, 78,
138, 178... Output pin, 41... Snap ring, 43, 143... Output gear, 48... Output member, 141... Stop washer.

Claims (1)

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