JP2000065159A - Internal tooth rocking type inscribed meshing planetary gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily ensure a through space for wiring, piping, etc., in the center part of a device as necessary, while intending to reduce the number of component items. SOLUTION: This gear device comprises a casing 101, external tooth gear 121 as an output member arranged in the casing 101, plurality of eccentric unit shafts 110, 111 arranged in the outer peripheral side of the external tooth gear 121 to be supported rotatably to the casing 101, eccentric units 110A, 111A provided in the eccentric unit shafts 110, 111, and an internal tooth rocking unit 112A meshed with the external tooth gear 121 to insert the eccentric unit also to be rockingly rotated by its rotation so as to rotate the external tooth gear 121. In this case, one of the eccentric unit shafts 110 is made unconnected to an input shaft rotationally driving the eccentric unit shaft and used exclusively for being driven to support the internal tooth rocking unit while drivenly rotating in response to the rocking of the internal tooth rocking unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external gear having an output member, and an internal oscillating body which meshes with the external gear is oscillated and rotated by an eccentric body, thereby obtaining a reduced rotation output to the external gear. The present invention relates to an internal gear oscillating type internal meshing planetary gear device.

[0002]

2. Description of the Related Art Internally meshing planetary gear devices are widely used in various reduction gear fields because of their advantages of being able to transmit a large torque and obtaining a large reduction ratio.

[0003] Among them, an external gear is used as an output member, and an internal tooth oscillating planet of an internal tooth oscillating type that takes out a rotation output by oscillating rotation of an internal tooth oscillating body meshed with the external gear by an eccentric body. A gear train is known from patent publication 2607937.

An example of the gear device will be described with reference to FIGS.

[0005] Reference numeral 1 denotes a casing, which comprises a first support block 1A and a second support block 1B connected to each other by a fastening member 2 such as a bolt or a pin. Reference numeral 5 denotes an input shaft, and a pinion 6 is provided at an end of the input shaft 5.
A plurality of transmission gears 7 arranged at equal angles around the input shaft 5
Is engaged.

The casing 1 has bearings 8 at both axial ends.
The three eccentric shafts 10 rotatably supported by 9 and having eccentric bodies 10A and 10B at the axial middle portion are provided at equal angular intervals (120-degree intervals) in the circumferential direction.
The transmission gear 7 is connected to the end of each eccentric shaft 10. The rotation of the transmission gear 7 in response to the rotation of the input shaft 5 causes all the eccentric shafts 10 to rotate in conjunction therewith.

Each of the eccentric shafts 10 penetrates through the through holes of the two internal tooth oscillating bodies 12A and 12B accommodated in the casing 1, and is provided in two stages adjacent to each other in the axial direction. Of the eccentric bodies 10A and 10B and the internal tooth oscillating body 12
Rollers 14 are provided between the inner circumferences of the through holes A and 12B.

On the other hand, an external gear 21 integrated with the end of the output shaft 20 is disposed in the center of the casing 1. , 1
Internal teeth 13 composed of 2B pins are meshed. The internal tooth oscillating bodies 12A and 12B are formed by cutting out the remaining parts except for the parts supporting the eccentric bodies 10A and 10B and the internal teeth 13 part, and thereby the first and second support blocks 1A and 1B are formed. In particular, the cross-sectional area of the connecting portion 1B can be increased.

This device operates as follows.

The rotation of the input shaft 5 is applied to a transmission gear 7 via a pinion 6, and the transmission gear 7 causes the eccentric shaft 10 to rotate.
Is rotated. The rotation of the eccentric body shaft 10 causes the eccentric body 1
When 0 is rotated, the internal-tooth oscillating bodies 12A and 12B oscillate and rotate. For this reason, the external gear 21 meshing with the internal tooth rockers 12A and 12B is rotated at a reduced speed. In this case, the phase of the internal tooth oscillating bodies 12A, 12B and the external gear 21 is shifted by the number of teeth due to one swing rotation of the internal tooth oscillating bodies 12A, 12B. The component becomes the (deceleration) rotation of the external gear 21, and a deceleration output is taken out from the output shaft 20.

[0011]

By the way, in the above-mentioned conventional internal gear oscillating type internally meshing planetary gear device, all three eccentric body shafts 10 are driven to rotate, so that the internal gear oscillating body 1 is rotated.
2A and 12B are oscillatingly rotated, and the number of input stage gears (transmission gears 7) is required by the number of eccentric shafts 10, and the number of parts is large.

In addition, because the three transmission gears 7 arranged at 120-degree intervals are rotated by one pinion 6, the pinion 6 and the input shaft are not provided unless an extra ring-shaped idle gear is provided. The position of 5 must be the center of the gear device (the center of the external gear 21), for example, by providing a through hole in the center of the gear device (= adopting a hollow shaft, etc.) and It was difficult to easily use it effectively for space such as wiring and wiring. Therefore, improvement has been demanded particularly in applications such as joint drive of industrial robots.

In the case where a plurality of reduction ratios are prepared without changing the reduction ratio of the internal meshing planetary gear portion, a combination set in which the gear ratio of the transmission gear 7 and the pinion 6 of the input stage is changed. There is a problem that a plurality of types must be prepared, and the number of parts increases. That is, for example, 1/4 and 1
In order to obtain a reduction ratio of / 2, 1/1 as shown in FIG.
A set of a transmission gear 7A and a pinion 6A for obtaining a reduction ratio of 4 and a set of a transmission gear 7B and a pinion 6B for obtaining a reduction ratio of 1/2 as shown in FIG. 13 must be prepared. The number of parts tended to increase.

The present invention takes the above circumstances into consideration, while reducing the number of parts and, if necessary, easily oscillating internal teeth at the center of the apparatus so that a through space such as wiring or piping can be secured. An object of the present invention is to provide an in-mold meshing planetary gear device.

[0015]

According to a first aspect of the present invention, there is provided a casing, an external gear as an output member disposed in the casing, and an outer gear disposed on an outer peripheral side of the external gear and rotatably mounted on the casing. A plurality of eccentric body shafts supported by the eccentric body shaft, the eccentric body meshes with the external gear, the eccentric body penetrates, and is rotated by the rotation of the eccentric body. An internal gear oscillating type internally meshing planetary gear device comprising: an internal gear oscillating body for rotating the external gear;
At least one of the plurality of eccentric body shafts is disconnected from an input shaft that rotationally drives the eccentric body shaft, and supports the internal tooth oscillating body while being driven to rotate according to the swing of the internal tooth oscillating body. The above-mentioned problem has been solved by making the motor driven only to be driven.

Conventionally, all the eccentric shafts have been driven as a matter of course, but if at least two eccentric shafts exist for one internal tooth oscillating body, the internal eccentric oscillating body will oscillate. Exercise can be given. For this reason, at least two drives are required,
With only two eccentric shafts, it may be difficult to receive and support the output torque load from the internal tooth oscillating body in a well-balanced manner. Therefore, at least one other eccentric body shaft is added, and is not used for driving but used exclusively for driven.

In the case where the eccentric shaft dedicated to driving is provided in this manner, a transmission gear is not required for the eccentric shaft. Therefore, the number of parts can be reduced as compared with the conventional device having the same number of eccentric shafts dedicated to driving. In particular, when a plurality of capacities and gear ratios are prepared as a series, the total number of stock parts can be drastically reduced.

Further, for example, when one of the three eccentric shafts is dedicated to driven, the pinion only needs to be meshed with only two transmission gears.
It is not necessary to provide the positions of the pinion and the input shaft at the center of the gear device, so that obstacles are eliminated from the center of the gear device, and a through space such as piping and wiring is easily provided at the center. And interference with the mating member can be avoided. Therefore, it is useful in, for example, an application for driving a joint of an industrial robot.

Further, since the position of the pinion can be freely set for the above reason, even when the reduction gear ratio is changed,
A desired reduction ratio can be obtained by changing the pinion diameter and the pinion position while using a common transmission gear. Therefore, the number of parts can be reduced because the transmission gear can be shared.

Further, both the input torque load and the output torque load are applied to the drive eccentric shaft, but only the output torque load is applied to the driven eccentric shaft without receiving the input torque load. Therefore, the load on the driven eccentric shaft can be reduced, and the diameter of the driven eccentric shaft can be reduced accordingly (claim 5).

According to a second aspect of the present invention, in the first aspect, the above problem is solved by disposing the eccentric shafts at irregular intervals in a circumferential direction around the external gear.

Here, consider the case where three eccentric shafts are provided.

When three eccentric shafts are equally arranged in the circumferential direction,
Although the interval is 20 degrees, in the present invention, for example, two eccentric shafts are arranged closer to one side at an interval smaller than 120 degrees, and the other eccentric shaft is arranged on the opposite side. Then, since the two eccentric shafts approached to one side approach each other, the size of the device in the linear direction connecting them can be reduced. Conventionally, the device had a shape based on a circle due to the equidistant arrangement of the eccentric body axes in the circumferential direction.
In the present invention, by arranging the eccentric shafts at unequal intervals, the degree of freedom in arranging the eccentric shafts is increased, and accordingly, the degree of freedom in designing the shape of the entire gear device can be increased. Thus, the width of the device when viewed from the front of the output shaft can be reduced, and a compact gear device having a slender shape as a whole can be manufactured.
This unequal arrangement has a large synergistic effect because the driven system does not require connection of the drive system wherever it is located.

According to a third aspect of the present invention, there are provided three eccentric shafts,
Two of the eccentric shafts are arranged close to each other at an interval of less than 120 degrees, and the other one is dedicated to the driven operation, and is placed on the opposite side to the two eccentric shafts that are close to each other. The arrangement solves the above-mentioned problem.

That is, the eccentric shafts for driving are arranged close to each other so that the driven eccentric shafts can be easily rotated in conjunction with each other by the transmission gear. By arranging them at different positions, the output torque reaction force from the internal tooth oscillator can be supported in a well-balanced manner.

The eccentric shaft need not always be arranged on the same circumference with respect to the center of the external gear. At least one of the eccentric shafts has a diameter different from that of the other eccentric shafts. They may be arranged on the circumference (claim 4). In such a case, the degree of freedom of design is further increased.

Further, even when the eccentric body shafts are unequally arranged,
Since there is a possibility that the load applied to each eccentric body axis and the eccentric body may change, the diameter of the eccentric body shaft (including the concept of the eccentric body) may be changed according to the way of applying the load (claim Item 5), the diameter of the eccentric body and the size of the bearing may be changed accordingly. For example, an eccentric body shaft or an eccentric body whose defense range has been widened by the arrangement of the eccentric body axis may have a large diameter. However, when the eccentric body shaft having a wider defense range is exclusively for driven use, the diameter can be reduced because the torque load is small. Therefore, it is preferable to set the diameter of the eccentric body shaft while measuring the necessity (strength) of the necessity of increasing the diameter and the necessity of reducing the diameter. However, even when the shaft diameter of the eccentric body shaft is made different, the eccentric amount of the eccentric body needs to be equalized with the others.

Further, by applying the above invention,
Since it is not necessary to dispose an input motor in the central portion of the gear device, in the invention of claim 6, a through hole is formed in the central portion of the external gear, and the through hole is formed with various pipes, wires, and the like. It becomes extremely easy to effectively use it as a space for performing.

[0029]

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

[First Embodiment] FIG. 1 is a sectional view of a main part of an internal gear oscillating type internally meshing planetary gear device (hereinafter, also simply referred to as "gear device") 100 according to a first embodiment.

In the gear device 100, the casing 10
By supporting at 1, the three eccentric shafts 110, 111, 111 are arranged at equal intervals (120 degrees intervals) in the circumferential direction around the center O of the gear device 100. Up to this point, it is the same as the conventional one. However, this gear train 10
At 0, only the two eccentric shafts 111, 111 of the three eccentric shafts 110, 111, 111 are used for driving and receiving the output torque reaction force, and the remaining one eccentric shaft 110 is used as the input shaft. The internal tooth rocking body 11
The internal tooth oscillating body 112A is driven and rotated in accordance with the oscillating motion of 2A.
(Only for receiving the output torque reaction force).

Therefore, two eccentric shafts 111 for driving,
A transmission gear 107 that meshes with a pinion 106A disposed at the center O of the gear device 100 is connected to an end of the gear 111, but the transmission gear is not provided on the eccentric shaft 110 dedicated to driven.

For other configurations, see FIG.
0, since it is basically the same as the conventional example shown in FIG. 11, the same or similar members are denoted by the same reference numerals in the drawings with the same lower two digits, and description thereof is omitted.

Next, the operation will be described.

The rotation of the input shaft (not shown) is controlled by the pinion 10
It is provided to two transmission gears 107 via 6A, and the two eccentric shafts 111, 111 are rotated by the transmission gear 107. The rotation of the eccentric body shaft 111 causes the eccentric body 111
When A is rotated, the internal tooth oscillating body 112A oscillates and rotates. Therefore, the external gear 121 meshing with the internal tooth oscillating body 112A is rotated at a reduced speed. In this case, the phase of the internal tooth oscillating body 112A and the external gear 121 are shifted by the number of teeth due to one swing rotation of the internal tooth oscillating body 112A. Gear 1
21 (deceleration) rotation, and a deceleration output is taken out from an output shaft (not shown).

In the above-described operation, the eccentric body shaft 110 dedicated to the driven rotation is driven by the swinging rotation of the internal tooth oscillating body 112A to support the output torque reaction force transmitted to the internal tooth oscillating body 112A. . Therefore, regarding the reaction force of the load torque, all the eccentric shafts 110, 111, 11
1 can be supported in a well-balanced manner.

In the case of the gear device 100, since the transmission gear 107 may be provided only on the two eccentric shafts 111, 111, the number of transmission gears 107 can be reduced from three to two, and the number of parts can be reduced. Can be reduced.

As can be seen by comparing FIGS. 1 and 2, when considering the provision of a reduction gear series corresponding to a plurality of reduction ratios (FIG. 1 shows a reduction ratio of 1/4, FIG. 2 shows a reduction ratio). Ratio 1 /
2) Using the same transmission gear 107, prepare pinions 106A and 106B having different diameters, and
06A, 106B, just by changing the arrangement of the input shaft,
A reduction gear having a plurality of reduction ratios can be provided. For this reason, conventionally, the transmission gear and the pinion had to be changed as a set, but only the pinions 106A and 106B need to be changed, so that the correspondence can be simplified and the number of parts can be reduced.

FIG. 2 shows a case where the input shaft, that is, the center position O1 of the pinion 106B is offset from the center O of the gear device 100. Thus, the two transmission gears 1
07, the position of the pinion 106B can be appropriately selected.

Therefore, FIGS. 3 and 4 show examples in which the pinion (gear) 106C is shifted outward from the center O of the gear device 100.

In this example, a pinion (gear) 106C
Are arranged at the center of the external gear 121 at a position where they do not cause any trouble. The diameter of the transmission gear 107C is set accordingly.

By driving one eccentric shaft 110 in this manner, the position of the pinion 106C can be adjusted.
Since it can be offset from the center O of 00, an input motor can also be arranged on one side, and compact arrangement is possible. Gear device 1
Since there is no obstacle (input shaft) at the center of 00, a through hole 121P having a large diameter D is formed in the external gear 121 or the output shaft 120, and this is effectively used as a space for wiring and piping. You can also do things. In addition,
Reference numerals 118 and 119 in FIG. 4 denote bearings that rotatably support the eccentric body shaft 111.

[Second Embodiment] FIGS. 5 to 8 are configuration diagrams of a gear device 600 according to a second embodiment of the present invention.

The gear device 600 includes a first support block 6 connected to each other by a fastening member 602 such as a bolt.
01A and a casing 601 composed of a second support block 601B. The outer peripheral position in the casing 601 is located at the center of the gear device 600, that is, the external gear 621.
Around the center O of the three eccentric shafts 610, 611, 6
11 (shown by an eccentric body 611A in FIG. 5 and shown by through holes 611P provided in a casing 601 for supporting the eccentric shaft 611 in FIG. 7) are bearings 608, 6
They are rotatably arranged via 09, 618, and 619, respectively. Here, three eccentric shafts 610, 611,
One of the eccentric shafts 610 of the 611 is set only for the driven operation, and only the other two eccentric shafts 611 and 611 are set for driving.

As shown in FIG. 5, three eccentric shafts 61
Eccentric body shaft 61 for driving two of 0, 611, 611
1, 611 are arranged on one side at an angular interval smaller than 120 degrees (in this example, an extremely small angle), and the other single eccentric shaft 610 dedicated to the following is connected to them by the gear device 6
It is located away from the center O of 00 at the opposite side.
The eccentric shaft 610 that is farther away is disposed at an equal angle from both eccentric shafts 611, 611 in consideration of the balance with the other two eccentric shafts 611, 611.

Accordingly, the three eccentric shafts 610, 611,
111 are arranged at irregular intervals in the circumferential direction with respect to the center O of the external gear 621. In addition, the driven eccentric shaft 610 is disposed on a different circumference from the center O with respect to the other two eccentric shafts 611 and 611.

Since only the two eccentric shafts 611 and 611 need be driven, the two eccentric shafts 6 for driving are required.
Pinion 606 and input shaft 605 for giving rotation to transmission gears 607, 607 provided at the ends of 11, 611
Are arranged outside the straight line connecting the eccentric body shafts 611, 611 when viewed from the center O of the gear device 600. As a result, the space near the center of the gear device 600 can be widely utilized by such an arrangement, and therefore, the external gear 62
A large-diameter through-hole 621P is formed at the center of the shaft 1, and the through-hole 621P is used as a space for various wirings and pipes, which is a so-called output shaft hollow shaft type gear device.

As shown in FIG. 6, the external gear 621 is rotatably supported on the inner periphery of the casing 601 via bearings 665 and 666.
6 is a flange 661 fixed with bolts 680 at both ends,
662 keeps it from moving in the axial direction. The output of the external gear 621 can be taken out by connecting an output member (not shown) (not shown) to a bolt hole 682 formed in one flange 662. In this case, since the input shaft 605 is shifted outward from the line connecting the two eccentric shafts 661, 661, the spatial interference between the mating machine and the input shaft 605 can be reduced accordingly.

The input shaft 605 has two eccentric shafts 611,
611, a fixed flange 6 of a motor 650 fixed to the casing 601 and its end face.
55 is rotatably supported by bearings 652 and 653, and is coupled to a rotating shaft 651 of the motor 650. A pinion 606 is provided at an end of the input shaft 605, and the pinion 606 meshes with a transmission gear 607 connected to each of the eccentric shafts 611, 611. When the transmission gear 607 rotates in response to the rotation of the input shaft 605, the eccentric shafts 611 and 611 rotate.

Each of the eccentric shafts 610, 611, 611 is composed of two internal tooth rockers 612 accommodated in the casing 601.
A, 612B penetrate through holes, respectively, and are formed in two stages of eccentric bodies 610A, 610B, 611 formed adjacent to the axially intermediate portions of the eccentric body shafts 610, 611, 611.
A, 611B and inner teeth rocking bodies 612A, 612B
A roller 614 is provided between the roller and the inner periphery of the through hole.

The external teeth 623 of the external gear 621 having the arc-shaped teeth formed of the pins are meshed with the internal teeth 613 of the trochoid teeth of the internal tooth oscillators 612A and 612B. The internal tooth oscillating bodies 612A and 612B are eccentric bodies 610A and 610.
B, 611A, and 611B, except for the internal teeth 613 and the inner teeth 613, are formed in a shape in which the remaining extra parts are cut out, and as shown in FIG. Is also provided.

Next, the operation will be described.

The operation of taking out the rotation of the input shaft 605 as the decelerated rotation to the external gear 621 is the same as that of the gear device 100 of the first embodiment. That is, the eccentric body shaft 610 at a remote position is not connected to the input shaft 605,
The internal oscillating bodies 612A and 612B are driven only by two eccentric shafts 611 and 611. The eccentric body shaft 610 at a distant position is driven and rotated in accordance with the swing of the internal tooth oscillators 612A and 612B, and the internal tooth oscillators 612A and 612 are rotated.
Performs a function exclusively for driven to support B.

In this case, two eccentric shafts 61 for driving are used.
The input torque load and the output torque load are applied to 1, 611, but the input torque load is not applied to the driven eccentric shaft 610, but only the output torque load is applied. Accordingly, the load on the eccentric body shaft 610 dedicated to the driven operation is small, so that the diameter can be reduced.

As described above, when the eccentric body shaft 610 dedicated to the driven is provided, a transmission mechanism (a transmission gear 607 or the like) for inputting the driven eccentric body shaft 610 is not required, so that the number of parts can be reduced. it can. In addition, since the output torque load can be received by the three eccentric shafts 610, 611, and 611 on average, effects such as stabilization of operation can be obtained.

Further, in the case of the gear device 600, the through hole 621P at the center of the external gear 621 can be used as an effective space for wiring or the like, so that the use can be expanded.

Further, in this gear device 600, the eccentric shafts 610, 611, 611 are arranged at unequal intervals in the circumferential direction, and in particular, the two eccentric shafts 611, 61 shifted to one side.
Since the devices 1 are arranged very close to each other, it is possible to greatly reduce the size of the device in a straight line direction (lateral direction on the paper) connecting them. For example, in the first embodiment, since the eccentric body axes are equally arranged in the circumferential direction, the device has a shape based on a circle, but in the present gear device 600, the internal gear oscillating members 612A and 612B start. As the casing 6
01 can also be formed in an elongated shape instead of a circle, and the width of the device can be greatly reduced, so that the gear device 600 having a thin and elongated shape as a whole can be manufactured.

Therefore, according to the present gear device 600, only the two eccentric shafts 611, 611 are used to drive the internal tooth oscillating bodies 612A, 612B. By arranging 611 at unequal intervals, the degree of freedom in shape design can be increased, including the arrangement of pinion 606 and input shaft 605.

[Third Embodiment] FIG. 9 is a sectional view of a main part of a gear device 700 according to a third embodiment of the present invention. In this gear device 700, three eccentric shafts 710, 711, 711
Are arranged at unequal intervals, and the eccentric body shaft 71 dedicated to driven
0 is larger than the other eccentric body shaft 711.

As described above, the eccentric shaft 710 dedicated to the following operation is used.
Is smaller than the driving eccentric shafts 711 and 711 at this point because the input torque load is not applied. However, since the three eccentric bodies 710, 711, 711 are arranged at irregular intervals, the eccentric shaft 710 has the largest defense range at this point, and the output torque load is large.
Therefore, in the third embodiment, the eccentric shaft 71
0 is dedicated to driven, and eccentric shafts 710, 71
Considering that the eccentric body shafts 710, 711, and 711 have different loads due to the arrangement of the eccentric bodies 710A and 711,
710B, 711A, and 711B have different diameters and bearing sizes. However, the eccentric bodies 710A, 710
The amounts of eccentricity of B, 711A, and 711B are all the same.

The other structure is basically the same as that of the first embodiment described above. Therefore, the same or similar members are denoted by the same reference numerals in the drawings with the same last two digits, and description thereof is omitted.

As described above, if the eccentric shafts 710, 711, and 711 having different diameters are used as necessary, each eccentric shaft 71
By averaging the load of 0, 711, 711 and the bearing, the life can be equalized.

The number of the internal tooth oscillating members, the number of the eccentric shafts, the tooth profile, and the like can be arbitrarily changed as long as a stable operation can be realized. In addition, the external gear can be integrally formed as long as the external gears have the same phase.

In order to oscillate the internal tooth oscillating body, it is necessary to synchronize two or more eccentric body axes and rotate them in the same phase. However, two driven eccentric body axes are synchronously rotated. With such a configuration, the driving can be performed with one eccentric shaft.

[0065]

As described above, according to the present invention,
By reducing the number of transmission gears, the number of parts can be reduced, and it is possible to easily secure a through space such as wiring and piping in the center of the device as necessary.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a configuration of a gear device 100 according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram when the reduction gear ratio of the gear device of the embodiment is changed.

FIG. 3 is a view showing an example in which a through hole is formed in the center of the gear device of the embodiment.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 5 is an essential part cross-sectional view showing a configuration of a gear device 600 according to a second embodiment of the present invention.

6 is a sectional view taken along the line VI-VI in FIG. 5;

7 is a view taken in the direction of arrows VII-VII in FIG. 6;

8 is a view taken in the direction of arrows VIII-VIII in FIG.

FIG. 9 is an essential part cross-sectional view showing a configuration of a gear device 700 according to a third embodiment of the present invention.

FIG. 10 is a side sectional view showing a configuration of a conventional gear device.

FIG. 11 is a sectional view taken along the line XI-XI in FIG. 19;

FIG. 12 is a configuration diagram when the reduction gear ratio of the gear device is changed.

FIG. 13 is a configuration diagram when the reduction gear ratio of the gear device is changed.

[Explanation of symbols]

 O: Center of gear device 100: Gear device 101: Casing 110: Eccentric shaft (eccentric shaft dedicated to driven) 111: Eccentric shaft 110A, 110B, 111A, 111B: Eccentric body 112A, 112B: Internal tooth oscillator 121 ... external gear 600 ... gear device 601 ... casing 610 ... eccentric body shaft (eccentric body shaft exclusively for driven) 611 ... eccentric body shaft 610A, 610B, 611A, 611B ... eccentric body 612A, 612B ... internal tooth oscillating body 621 ... outside Tooth gear 621P ... Through hole 700 ... Gear device 701 ... Casing 710 ... Eccentric body shaft (eccentric body shaft exclusively for driven) 711 ... Eccentric body shaft 710A, 711A ... Eccentric body 712A ... Internal tooth oscillating body 721 ... External gear

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Taku Haga 6-1, Asahimachi, Obu-shi, Aichi F-term in Nagoya Works, Sumitomo Heavy Industries, Ltd. F-term (reference) 3J027 FA19 FA36 FB32 GB05 GB09 GC03 GC23 GC26 GD03 GD08 GD12 GE01 GE29

Claims (6)

[Claims] 1. A casing, an external gear as an output member disposed in the casing, a plurality of eccentric shafts disposed on an outer peripheral side of the external gear and rotatably supported by the casing, An eccentric body provided on the eccentric body shaft, and an internal gear oscillating body that meshes with the external gear and penetrates the eccentric body and is rotated by the rotation of the eccentric body to rotate the external gear. Wherein at least one of the plurality of eccentric shafts is not connected to an input shaft that rotationally drives the eccentric shaft. An internal tooth oscillating type internally meshing planetary gear device, which is exclusively driven by supporting an internal tooth oscillating body while being driven to rotate in accordance with the oscillating motion of a moving body. 2. The internal gear oscillating internal meshing planetary gear device according to claim 1, wherein the eccentric shafts are arranged at irregular intervals in a circumferential direction around the external gear. 3. The eccentric shaft according to claim 2, wherein three eccentric shafts are provided, and two eccentric shafts are arranged close to each other at an interval of less than 120 degrees, and the other eccentric shaft is dedicated to the driven shaft. The internal gear oscillating type internally meshing planetary gear device is arranged on the opposite side to the two eccentric shafts approaching each other. 4. The internal tooth oscillating type according to claim 1, wherein the driven eccentric body shaft is arranged on a circumference having a diameter different from that of the other eccentric body shafts. An internally meshing planetary gear set. 5. The internal gear according to claim 1, wherein the driven eccentric shaft has a diameter different from that of the other eccentric shaft with respect to the center of the external gear. Oscillating internal gear planetary gear system. 6. The internal gear oscillating internal meshing planetary gear device according to claim 1, wherein a through hole is formed in a central portion of said external gear.