JP2000065158A - Internal tooth rocking type inscribed meshing planetary gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a freedom degree of design of a device shape and make dimensions contractible. SOLUTION: This planetary gear device comprises a casing 101, external tooth gear 121 as an output member arranged in the casing, plurality of eccentric unit shafts 110, 111 arranged in an external peripheral side of the external tooth gear to be supported rotatably to the casing, eccentric units 110A, 111A provided in the eccentric unit shaft, and an internal tooth rocking unit 112A meshed with the external tooth gear to insert the eccentric unit also to be rockingly rotated by its rotation so as to rotate the external tooth gear. In this case, the eccentric unit shafts 110, 111 are arranged with an unequal space (70 deg., 145 deg., 145 deg.) in a circumferential direction with the external tooth gear serving as the center.

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 eccentric shafts 10 rotate when the transmission gear 7 rotates in response to the rotation of the input shaft 5.

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]

In the above-mentioned conventional internal gear oscillating type internally meshing planetary gear device, three eccentric shafts 10 are arranged at regular intervals (120 degrees) in the circumferential direction. (Equally distributed) and the outer shape of the casing 1 is accordingly circular, which limits the size reduction. For example, as an application for the joint of an industrial robot, FIG.
When there is a request to reduce the width of the apparatus as viewed from the front indicated by X of 0, the arrangement of the eccentric shafts 10 which are equally arranged hinders, and there is a limit in realizing the request.

The present invention has been made in view of the above circumstances, and has as its object to provide an internal gear oscillating type internal meshing planetary gear device capable of increasing the degree of freedom in designing the device shape and reducing the size.

[0013]

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;
The above problem has been solved by disposing the eccentric body shafts at irregular intervals in the circumferential direction around the external gear.

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

If the three eccentric shafts are equally arranged in the circumferential direction,
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. To place. 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, since the eccentric shafts are equally arranged in the circumferential direction, the device has a circular shape. However, in the present invention, the eccentric shafts are arranged at irregular intervals. Since the degree of freedom in the arrangement of the shaft is increased, the degree of freedom in designing the shape of the entire gear device can be increased accordingly. As a result, as described above, the width of the device when viewed from the front of the output shaft can be reduced, and a compact gear device having an elongated shape as a whole can be manufactured. For example, an industrial robot It is useful for driving joints.

If one of the remaining eccentric shafts is arranged at an equal angle from the other two eccentric shafts, the balance can be stabilized (claim 2).

The number of the eccentric shafts may be at least two. In this case, the two eccentric shafts are arranged at an angular interval smaller than 180 degrees (the opposite side is naturally larger than 180 degrees). Item 3). As a result, the distance between the two eccentric shafts is smaller than in the case where they are equally spaced at 180 ° intervals,
As in the above three examples, the width of the apparatus can be reduced.

The number of the eccentric shafts may be four. In this case, two eccentric shafts are provided on one side and two eccentric shafts are provided on the opposite side. Can be shortened. The same applies when more eccentric body shafts are provided.

In any case, by arranging the eccentric shafts at unequal intervals, it is possible to determine the arrangement of the eccentric shafts by giving priority to the external appearance of the apparatus (= the degree of freedom in the design of the shape is small). Increase). For this reason, the device dimensions can be accommodated within a desired width.

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

In addition, due to the unequal arrangement of the eccentric shafts, there is a possibility that the manner in which loads are applied to each eccentric shaft and eccentric body will change. Therefore, the diameter of the eccentric body shaft (including the concept of the eccentric body) may be changed depending on how the load is applied. That is, at least one of the eccentric shafts may have a different diameter from the other eccentric shafts (claim 5), and 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, in that case, the amount of eccentricity of the eccentric body needs to be equalized with the others.

Further, it is not always necessary to drive all the eccentric shafts. At least one of the plurality of eccentric shafts is not connected to the input shaft for driving the eccentric shaft to rotate. It may be a driven-only one that supports the internal tooth oscillating body while being driven and rotated in accordance with the swing of the moving body (claim 6). In this case, an input torque load and an output torque load are applied to the drive eccentric shaft, but only an output torque load is applied to the driven eccentric shaft without input torque load. Accordingly, the load on the eccentric body shaft exclusively used for the driven side is small, so that the diameter can be reduced. As described above, when the eccentric body shaft dedicated to the following operation is provided, a transmission mechanism (a transmission gear or the like) for input need not be provided for the eccentric body shaft itself, so that the number of parts can be reduced.

Conventionally, the internal tooth oscillating body naturally has internal teeth that are continuous over the entire circumference, but depending on the number of internal tooth oscillating bodies, the internal tooth oscillating body may be continuously continuous over the entire circumference by appropriately shifting the phase. It is possible to rotate the external gear without using the internal teeth.

For example, a single internal tooth oscillating body requires internal teeth that are continuous over the entire circumference, but with two internal tooth oscillating bodies, if the meshing phase with the external gear is shifted by 180 degrees, the internal teeth are oscillated. It suffices if the formation range is set to 180 degrees or more, which is 1/2 of the entire circumference.

Similarly, in the three internal tooth oscillating bodies, if the meshing phase with the external gear is shifted by 120 degrees, the range of forming the internal teeth should be 120 degrees or more, which is 1/3 of the entire circumference. In the four internal tooth oscillating bodies, if the meshing phase with the external gear is shifted by 90 degrees, the formation range of the internal teeth should be 90 degrees, which is １ ／ of the entire circumference.

Therefore, in the invention of claim 7, the range of formation of the internal teeth of the internal tooth oscillating body is set as a part of the circumference. In the invention of claim 8, the internal teeth of the internal tooth oscillating body are discontinuous in the circumferential direction.

By arranging the internal teeth unequally as described above, the internal teeth of the internal tooth oscillating body can be part of the circumference or discontinuous in the circumferential direction. This makes it possible to design the internal tooth oscillating body into a free shape other than a circular shape. Therefore, the size can be further reduced, and the gear device can be made more compact.

Further, by applying the above invention,
Since it is not necessary to dispose an input motor in the center of the gear device, in the invention of claim 9, a through hole is formed in the center of the external gear, and the through hole is formed with various pipes, wires, and the like. That can be used effectively 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 cross-sectional view orthogonal to the axial direction of an internal gear oscillating type internally meshing planetary gear device (hereinafter, also simply referred to as a "gear device") 100 according to a first embodiment. 2
FIG. 2 is a sectional view taken along the line II-II of FIG.

The gear device 100 includes a first support block 1 connected to each other by a fastening member 102 such as a bolt.
01A and a casing 101 composed of a second support block 101B. The three eccentric shafts 1 around a center O (a center of an external gear 121 and an output shaft 120 to be described later) O of the gear device 100 are provided at positions on the outer peripheral side in the casing 101.
10, 111, 111 are bearings 108, 109, 11
8 and 119 are provided rotatably.

As shown in FIG. 1, three eccentric shafts 11
0, 111 and 111, two eccentric shafts 111 and 1
11 is an angle interval smaller than 120 degrees (70 in this example).
Degrees), placed on one side and the remaining one eccentric shaft 1
10 are arranged on the opposite side of the center O of the gear train 100 from them. Here, the eccentric body shaft 110 that is farther away is disposed at a position equiangular (145 degrees in this example) from the other two eccentric body shafts 111, 111.

Therefore, the three eccentric shafts 110, 111,
111 are arranged at irregular intervals in the circumferential direction with respect to the center O of the gear device 100. However, the three eccentric shafts 110, 111, 111 are arranged on the same circumference centering on the center O of the gear device 100.

In FIG. 2, reference numeral 105 denotes an input shaft which is disposed concentrically with the center O of the gear device 100.
A pinion 106 is provided at an end of the pin 05. The pinion 106 meshes with a transmission gear 107 connected to the end of each of the eccentric shafts 110, 111, 111. When the transmission gear 107 rotates in response to the rotation of the input shaft 105, the eccentric shafts 110, 111, 111 rotate.

Each of the eccentric shafts 110, 111, 111 is provided with two internal tooth oscillating bodies 112 accommodated in the casing 101.
A, 110B, 111B, 111A, 110B, and 111C. Two stages of eccentric bodies 110A, 110B, 111 formed adjacent to the axially intermediate portions of the eccentric shafts 110, 111, 111, respectively.
A, 111B and the internal tooth rocking bodies 112A, 112B
Rollers 114 are provided between the inner circumferences of the through holes.

On the other hand, at the center of the casing 101,
An integrated external gear 121 is disposed at an end of the output shaft 120. An external gear 123 having a trochoidal tooth shape of the external gear 121 is provided with an arcuate tooth shape including pins of the internal tooth oscillators 112A and 112B. The internal teeth 113 are engaged. The internal tooth oscillating bodies 112A, 112B are eccentric bodies 110A, 110
Except for the portions supporting B, 111A, 111B and the internal teeth 113, the remaining portions are formed in a cutout shape.

The two eccentric shafts 111, 1
11 is formed with a small diameter, but one eccentric body shaft 110 that is separated is formed with a larger diameter than them. this is,
Since the eccentric shafts 110, 111, 111 are arranged at unequal intervals, the manner in which loads are applied to the eccentric shafts 110, 111, 111 differs. Accordingly, the eccentric bodies 110A, 110B,
111A, 111B diameter and bearings 108, 109, 11
The sizes of 8, 109 are also different. However, eccentric body 1
The eccentric amounts of 10A, 110B, 111A, and 111B are all uniform. By doing so, each eccentric body shaft 11
0, 111, 111 and bearings 108, 109, 118, 1
09 are averaged, and the lifespan is equalized.

Next, the operation will be described.

The operation in which the rotation of the input shaft 105 is decelerated and taken out to the output shaft 120 is the same as in the conventional example. The difference is the overall shape of the gear device 100.

That is, in the gear device 100 of the present embodiment,
The eccentric shafts 110, 111, 111 are arranged at unequal intervals in the circumferential direction, and particularly the two eccentric shafts 11 shifted to one side.
Since the devices 1 and 111 are close to each other, the size of the device in the linear direction connecting them can be greatly reduced. For example, in the related art, since the eccentric body axes are equally arranged in the circumferential direction, the device has a shape based on a circle. However, in the present embodiment, the casing 101 also includes the internal tooth oscillators 112A and 112B. , Can be formed into an elongated shape instead of a circle, and the width dimension of the device can be greatly reduced, so that the gear device 100 having an elongated shape as a whole can be manufactured.

[Second Embodiment] FIG. 3 is a sectional view of a main part of a gear device 200 according to a second embodiment of the present invention.

Even if the number of eccentric body shafts is at least two, the internal tooth oscillating body can be oscillated stably. Thus, in the gear device 200 of the second embodiment, the eccentric shaft on the remote side in the first embodiment is omitted, and the two eccentric shafts 2
It has a structure in which only 11 and 211 are arranged.

Other structures are basically the same as those of the first embodiment described above, and therefore, the same or similar members are denoted by the same reference numerals in the figures, and the description thereof is omitted.

Omitting the eccentric shaft on the remote side in this way,
When only two eccentric shafts 211, 211 are provided, the number of parts is reduced and the size can be further reduced, so that a more compact structure can be achieved.

[Third Embodiment] FIGS. 4 to 7 are configuration diagrams of a third embodiment of the present invention.

As in the conventional example or the first embodiment, 3
When all the eccentric shafts are driven, the input shaft must be arranged concentrically with the center of the gear device because the three transmission gears arranged in the circumferential direction must rotate equally. In many cases (otherwise, it is necessary to displace the position of the input shaft from the center of the gear train by arranging an idle gear one extra stage to rotate the three transmission gears).

However, when only two eccentric shafts are used as in the second embodiment, the number of transmission gears is two, so that the positions of the pinion and the input shaft can be freely set. That is, the input shaft can be removed from the center of the gear device with a simple structure without a special idle gear or the like.

The gear device 300 according to the third embodiment implements this.

As shown in FIG. 4 to FIG.
The first support block 301A and the second support block 3 are connected to each other by a fastening member 302 such as a bolt.
01B. At a position on the outer peripheral side in the casing 301, two eccentric shafts 311 and 311 are rotatable via bearings 318 and 319 around the center of the gear device 300, that is, around the center O of the external gear 321. It is arranged in.

Here, the two eccentric shafts 311 and 311
(In FIG. 4, indicated by an eccentric body 311A, and in FIG. 6, indicated by a through hole 311P provided in a casing 301 for supporting the eccentric shaft 311), they are arranged at positions very close to each other, The input shaft 305 for giving rotation to the transmission gears 307 provided at the end of each eccentric shaft 311, 311 is viewed from the center O of the gear device 300, rather than a straight line connecting the eccentric shafts 311, 311. It is located outside. As a result, the space near the center of the gear device 300 can be widely used, so that a large-diameter through hole 321P is formed at the center of the external gear 321 and this through hole 3
21P is a so-called output shaft hollow shaft type gear device that is used as a space for various wirings and pipes.

As shown in FIG. 5, the external gear 321 is rotatably supported on the inner circumference of the casing 301 via bearings 365 and 366.
6 is a flange 361 fixed with bolts 380 at both ends,
It is held by 362 so as not to move in the axial direction. The output of the external gear 321 can be taken out by connecting an unillustrated output-side member (a counterpart machine) to a bolt hole 382 formed in one flange 362. In this case, since the input shaft 305 is shifted outward from the line connecting the two eccentric shafts 311 and 311, the spatial interference between the mating machine and the input shaft 305 can be reduced accordingly.

The input shaft 305 has two eccentric shafts 311,
311, a fixed flange 3 of the motor 350 fixed to the casing 301 and its end face.
The motor 350 is rotatably supported by bearings 352 and 353, and is coupled to a rotation shaft 351 of the motor 350. A pinion 306 is provided at an end of the input shaft 305, and the pinion 306 meshes with a transmission gear 307 coupled to each of the eccentric shafts 311, 311. When the transmission gear 307 rotates in response to the rotation of the input shaft 305, each of the eccentric shafts 311 and 311 rotates.

Each of the eccentric body shafts 311 and 311 is provided with two internal tooth oscillating bodies 312A and 312 housed in the casing 301.
B, each penetrating through the through hole, and each eccentric body shaft 31
The outer circumferences of two-stage eccentric bodies 311A and 311B formed adjacent to the axial middle part of the first and third parts, and the internal tooth oscillating body 312
A roller 314 is provided between A and the inner periphery of the through hole of 312B.

The external teeth 323 of the external gear 321 are meshed with the internal teeth 313 composed of pins of the internal tooth oscillating bodies 312A and 312B. The internal tooth oscillating bodies 312A and 312B are formed in a shape in which the remaining extra parts are cut out except for the parts supporting the eccentric bodies 311A and 311B and the internal teeth 313, and as shown in FIG. A lightening hole 312P for weight reduction is also provided.

In the case of this gear device 300, the external gear 3
Since the through hole 321P at the center of 21 can be used as an effective space for wiring or the like, the use can be expanded. The deceleration operation is the same as in the previous embodiment.

[Fourth Embodiment] FIG. 8 is a sectional view of a main part of a gear device 400 according to a fourth embodiment of the present invention. In this gear device 400, the tooth shapes of the internal teeth 413 and the external teeth 423 are reversed. That is, the internal teeth 413 of the internal tooth oscillating body 412A are formed in a trochoid tooth shape, and the external teeth 423 of the external gear 421 are formed.
Are constituted by arcuate teeth formed of pins.

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

[Fifth Embodiment] FIG. 9 is a sectional view of a main part of a gear device 500 according to a fifth embodiment of the present invention. The gear device 500 includes an input shaft 505, two eccentric shafts 511,
511 are arranged on a straight line. This prevents a radial load from being applied to the input shaft 505 (although the space around the output shaft is slightly smaller than in the fourth embodiment).

The other structure is basically the same as that of the third embodiment described above, and 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.

[Sixth Embodiment] FIGS. 10 to 13 are configuration diagrams of a gear device 600 according to a sixth embodiment of the present invention.

In this gear device 600, in addition to two adjacent eccentric shafts 611, 611, another eccentric shaft 610 is arranged on the opposite side of them. The arrangement of the three eccentric shafts 610, 611, 611 is similar to that of the gear device 100 of the first embodiment, but the feature of the gear device 600 of the present embodiment is that the eccentric shaft 610 provided at a remote position. Is not driven by the input shaft 605.

That is, the eccentric body shaft 610 provided at a remote position
Is not connected to the input shaft 605, and the internal tooth rocking body 612
A and 612B are driven only by the two eccentric shafts 611 and 611 as in the third embodiment. Further, the eccentric body shaft 610 located at a distant position is provided with the internal tooth oscillating bodies 612A and 612.
While rotating in accordance with the swing of B, the internal tooth oscillator 612A,
It performs a function dedicated to the following that supports the 612B.

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 shaft 610 dedicated to the driven operation is provided, the transmission mechanism (the transmission gear 607 and the like) for inputting the driven eccentric shaft 610 is not required, and thus the gear device 100 of the first embodiment is provided. The number of parts can be reduced as compared with the gear device 300, and the number of components can be reduced by two compared with the gear device 300 of the third embodiment.
This has the effect of reducing the load on the eccentric shafts 611, 611 and stabilizing the operation.

It is not necessary to drive the eccentric shaft 610 at a distant position, so that the other two eccentric shafts 610 are not driven.
11 and 611 are arranged on a circumference having a different diameter.

The other structure is basically the same as the above-described third embodiment or the first embodiment (with respect to the support mechanism of the eccentric shaft 610 at a distant position), so that the same or similar members are used. The same reference numerals are given to the last two digits in the figure, and the description is omitted.

[Seventh Embodiment] FIG. 14 is a sectional view of a main part of a gear device 700 according to a seventh embodiment of the present invention, and FIG.
FIG. 5 is a sectional view taken along the line XV-XV of FIG.

Conventionally, in this type of internally meshing planetary gear device, the internal tooth oscillating body naturally has internal teeth that are continuous over the entire circumference, but depending on the number of internal tooth oscillating bodies, the phase can be appropriately adjusted. The external gear can be rotated without using the internal teeth that are continuous over the entire circumference. For example,
In the case of using three internal tooth oscillating bodies, if the meshing phase with the external gear is shifted by 120 degrees, the formation range of the internal teeth is reduced to 1 / one of the entire circumference.
3, it is sufficient to set the angle to 120 degrees or more.

Therefore, in this gear device 700, three internal tooth oscillators 712A, 712B, 712C are disposed in the casing 701, and the internal tooth oscillators 712A, 712B,
The internal teeth 713 of the 712C are shifted in phase by 120 degrees, and are formed only in the range of the formation angle α = 120 degrees (actually slightly larger). Then, the three internal tooth rockers 712A, 71 arranged so as to overlap at substantially the same position.
2B and 712C, two eccentric shafts 711 and 711 are made to penetrate, and by rotation of the eccentric shafts 711 and 711, 120
The rocking motions are shifted in phase by degrees.

The other structure is basically the same as that of the above-described second embodiment. 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.

In this gear device 700, the internal tooth oscillating body 71
Since the dimensions of 2A, 712B, and 712C can be minimized, further downsizing can be achieved.

FIG. 16 is a diagram showing a change in load received by one external gear 721 from three internal rocking members 712A, 712B, and 712C in rows A, B, and C.

In the figure, three curves obtained by combining the solid line and the broken line show the force that one external gear 721 receives from the internal tooth oscillating body in which the internal teeth 713 are continuously present all around the circumference.
Curves with only solid lines are the internal tooth oscillating bodies 7 in rows A, B, and C.
When 12A, 712B, and 712C have the internal tooth 713 only in the range of 120 degrees, the force which the output shaft 720 receives is shown.

As is apparent from this figure, even when the internal teeth 713 are provided only in the range of 120 degrees, the output shaft 720 is continuously loaded in the order of row A → row B → row C. Therefore, the output shaft 720 can be rotated without difficulty.

Since the internal teeth do not need to be present all around, it can be configured as shown in FIGS. 17 and 18.

[Eighth Embodiment] FIG. 17 is a sectional view of a main part of a gear device 800 according to an eighth embodiment of the present invention.

In the seventh embodiment, two eccentric shafts 7
11 and 711 (see FIG. 16), but in this gear device 800, two eccentric shafts 811 and 811 are additionally provided on the opposite side in the same manner.

In other words, a total of four eccentric shafts 811 are arranged at unequal intervals, two at a time, approaching each other and in a 180 ° facing relationship. The four eccentric body shafts 811 are adapted to rotate in conjunction with each other, and the internal tooth oscillating body 81 is divided into two.
2A-1 and 812A-2 are connected to two eccentric shafts 8 respectively.
The eccentric bodies 811A and 811A of 11 and 811 are configured to swing and rotate.

The divided internal tooth oscillators 812A-1, 81
In the case of 2A-2 having an arrangement of three rows of internal tooth oscillating bodies as in the seventh embodiment, it is sufficient that both of them have internal teeth 823 in a range of 120 degrees, and each of them has about 60 degrees.
It just needs to cover the range of degrees. Of course, one row of internal tooth oscillators (in this case, two divided internal tooth oscillators 812
The number of rows can be increased or decreased depending on the range covered by the internal teeth 813 in A-1 and 812A-2).

Further, the internal tooth oscillating body 812 opposed by 180 degrees
If the phases of A-1 and 812A-2 are shifted, the internal tooth oscillating bodies arranged in multiple rows at the same position can be arranged in the same plane, so that the axial dimension can be reduced.

Since the other construction is basically the same as that of the above-described seventh embodiment, the same or similar members are denoted by the same reference numerals in the drawings with the same last two digits, and the description is omitted.

In this manner, by making the internal teeth of the internal tooth oscillating body discontinuous in the circumferential direction (divided shape), the internal tooth oscillating body can be designed in a free shape. Therefore, the size of the gear device 800 in the intended direction can be further reduced.

[Ninth Embodiment] FIG. 18 is a sectional view of a main part of a gear device 900 according to a ninth embodiment of the present invention.

In this gear device 900, the internal tooth rocking body 812A-2 on one side opposed by 180 degrees in the eighth embodiment.
(See FIG. 17) is further divided into two, and the internal tooth oscillating bodies in the same plane are totally three internal tooth oscillating bodies 912A-1 and 912A.
-2, 912A-3. Two eccentric body shafts 911 and 911 penetrate through each of the internal tooth oscillators 912A-1, 912A-2 and 912A-3. Therefore, here, a total of six eccentric shafts 91
1 is used.

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

As described above, by dividing the internal tooth oscillating body into a plurality of parts, the structure becomes complicated, but the degree of freedom in the shape design of the gear device can be greatly increased.

The eccentric shafts 911 (the four upper ones in FIG. 18) whose load has been reduced due to the unequal arrangement of the eccentric shafts 911.
Can be smaller in diameter than the eccentric body shaft 911 on the opposite side (the two on the lower side in FIG. 18).

The embodiments of the present invention have been described above. However, the number of the internal tooth oscillating bodies, the number of the eccentric body shafts, the tooth shape, and the like can be arbitrarily changed as long as a stable operation can be realized. is there. In addition, the external gear can be integrally formed as long as the external gears have the same phase.

[0089]

As described above, according to the present invention,
Since the eccentric shafts are arranged at irregular intervals, the arrangement of the eccentric shafts can be determined by giving priority to the external shape of the apparatus, and the degree of freedom in shape design can be greatly increased. For this reason, the device dimensions can be accommodated within a desired width.

[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 sectional view taken along the line II-II of FIG.

FIG. 3 is a sectional view of a main part showing a configuration of a gear device 200 according to a second embodiment of the present invention.

FIG. 4 is an essential part cross-sectional view showing a configuration of a gear device 300 according to a third embodiment of the present invention.

FIG. 5 is a sectional view taken along the line V-V in FIG. 4;

6 is a view taken in the direction of arrows VI-VI in FIG. 5;

FIG. 7 is a view taken in the direction of arrows VII-VII in FIG. 5;

FIG. 8 is a sectional view of a main part showing a configuration of a gear device 400 according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a main part showing a configuration of a gear device 500 according to a fifth embodiment of the present invention.

FIG. 10 is a sectional view of a main part showing a configuration of a gear device 600 according to a sixth embodiment of the present invention.

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

12 is a view taken in the direction of arrows XII-XII in FIG. 11;

13 is a view taken in the direction of arrows XIII-XIII in FIG. 5;

FIG. 14 is a sectional view of a main part showing a configuration of a gear device 700 according to a seventh embodiment of the present invention.

15 is a sectional view taken along the line XV-XV in FIG.

FIG. 16 is a characteristic diagram of the seventh embodiment.

FIG. 17 is a sectional view of a main part showing a configuration of a gear device 800 according to an eighth embodiment of the present invention.

FIG. 18 is a sectional view of a main part showing a configuration of a gear device 900 according to a ninth embodiment of the present invention.

FIG. 19 is a side sectional view showing the configuration of a conventional gear device.

20 is a sectional view taken along the line XX-XX in FIG. 19;

[Explanation of symbols]

O: Center of gear device 100: Gear device 101: Casing 110, 111: Eccentric shaft 110A, 110B, 111A, 111B: Eccentric body 112A, 112B: Internal oscillating body 121: External gear 200: Gear device 201: Casing 211 ... eccentric body shaft 211A ... eccentric body 212A ... internal tooth oscillating body 221 ... external gear 300 ... gear device 301 ... casing 311 ... eccentric body shaft 311A, 311B ... eccentric body 312A, 312B ... internal tooth oscillating body 321 ... external tooth Gear 321P ... Through hole 400 ... Gear device 401 ... Casing 411 ... Eccentric body shaft 411A ... Eccentric body 412A ... Internal tooth oscillating body 421 ... External gear 421P ... Through hole 500 ... Gear device 501 ... Casing 511 ... Eccentric body shaft 511A ... Eccentric body 512A ... Internal tooth oscillating body 521 ... External gear 521P ... Through-hole 600: Gear device 601: Casing 610, 611: Eccentric shaft 610A, 610B, 611A, 611B: Eccentric body 612A, 612B: Internal tooth oscillator 621: External gear 621P: Through hole 700: Gear device 701: Casing 711: Eccentric body shaft 711A, 711B, 711C ... Eccentric body 712A, 712B, 712C ... Internal tooth oscillating body 721 ... External gear 800 ... Gear device 801 ... Casing 811 ... Eccentric body shaft 811A ... Eccentric body 812A-1, 812A-2 ... Internal tooth oscillating body 821: external gear 900: gear device 901: casing 911: eccentric body shaft 911A: eccentric body 912A-1, 912A-2, 912A-3: internal tooth oscillating body 921: external gear

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Taku Haga 6-1-1 Asahimachi, Obu City, Aichi Prefecture Sumitomo Heavy Industries Machinery Co., Ltd. Nagoya Works F-term (reference) 3J027 FA36 FB32 FC12 GB05 GB09 GC03 GC23 GC26 GD03 GD08 GD12 GE01 GE29

Claims (9)

[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 rocking body that meshes with the external gear and penetrates the eccentric body and is oscillated by the rotation of the eccentric body to rotate the external gear. Wherein the eccentric body shafts are arranged at unequal intervals in the circumferential direction around the external gear. An internally meshing planetary gear set. 2. The eccentric shaft according to claim 1, wherein three eccentric shafts are provided, and two eccentric shafts are arranged closer to each other at an interval of less than 120 degrees, and the other eccentric shaft is connected to the two An internal gear oscillating internal meshing planetary gear device which is arranged on a side opposite to an eccentric body axis and at an equal angular interval from both eccentric body axes. 3. The internal tooth oscillating mold according to claim 1, wherein two eccentric shafts are provided, and the two eccentric shafts are arranged close to each other at an interval of less than 180 degrees. Meshing planetary gear set. 4. The eccentric shaft according to claim 1, wherein at least one of the plurality of eccentric shafts has a diameter different from the center of the external gear from other eccentric shafts. An internal gear oscillating type internal meshing planetary gear device, wherein the planetary gear device is disposed above. 5. The internal gear oscillating type internal mesh according to claim 1, wherein at least one of the eccentric shafts has a different diameter from the other eccentric shafts. Planetary gear set. 6. The internal tooth oscillating body according to claim 1, wherein at least one of the plurality of eccentric body shafts is not connected to an input shaft that rotationally drives the eccentric body shaft. An internal gear oscillating internal meshing planetary gear device which is driven exclusively for supporting an internal gear oscillating body while being driven and rotated in accordance with the rocking. 7. The internal gear oscillating type internally meshing planetary gear device according to claim 1, wherein a range of forming the internal teeth of the internal tooth oscillating body is a part of a circumference. . 8. The internal gear oscillating type internally meshing planetary gear device according to claim 1, wherein the internal teeth of the internal tooth oscillating body are discontinuous in a circumferential direction. . 9. The internal gear oscillating type internally meshing planetary gear device according to claim 1, wherein a through hole is formed in a central portion of said external gear.