JP3034629B2 - Trochoid tooth type inscribed planetary gear structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trochoid-type inscribed planetary gear structure in which an inner pin is supported at both ends, which is particularly easy to assemble and disassemble.

[0002]

2. Description of the Related Art Conventionally, a first shaft, an eccentric body rotated by rotation of the first shaft, an external gear mounted on the eccentric body via a bearing and capable of eccentric rotation, and an external gear An internal gear internally meshed with the gear, an internal roller hole provided in the external gear, and an inner pin loosely fitted in the internal roller hole;
A trochoid-type inscribed planetary gear structure having one end of the inner pin and a second shaft to which only the rotation component of the external gear is transmitted is widely known.

FIGS. 4 and 5 show a concrete example of this structure in the related art.
Shown in

In this conventional example, the above structure is applied to a "reduction gear" by using the first shaft as an input shaft, the second shaft as an output shaft, and fixing an internal gear.

The input shaft 1 has a predetermined phase difference (18 in this example).
0 °), the eccentric bodies 3a and 3b are fitted. The eccentric bodies 3a and 3b are respectively connected to the input shaft 1 (center O ₁ ).
Is eccentric by the amount of eccentricity e (center O ₂ ). Two external gears 5a, 5b are mounted on each eccentric body 3a, 3b in a double row via bearings 4a, 4b. The external gears 5a and 5b have inner roller holes 6a and 6b, respectively.
Are provided, and the inner pin 7 and the inner roller 8 are fitted therein.

The reason why the number of external gears is two (double row) is as follows.
This is mainly to increase transmission capacity, maintain strength, and maintain rotational balance.

[0007] External teeth 9 having a trochoidal waveform or a circular arc waveform are provided on the outer periphery of the external gears 5a and 5b. The external teeth 9 are internally meshed with an internal gear 10 fixed to a casing 12. Specifically, the internal teeth of the internal gear 10 have a structure in which the outer pin 11 is loosely fitted in the outer pin hole 13 and held so as to be easily rotated.

The inner pin 7 penetrating the external gears 5a, 5b is fixed or fitted to the flange 2a of the output shaft 2.

When the input shaft 1 makes one rotation, the eccentric bodies 3a, 3b
Rotates once. By one rotation of the eccentric bodies 3a and 3b,
The external gears 5a and 5b are oscillating about the input shaft 1. However, since the rotation of the external gears 5a and 5b is restricted by the internal gear 10, the external gears 5a and 5b Mostly only swinging is performed while touching.

For example, if the number of teeth of the external gears 5a and 5b is N and the number of teeth of the internal gear 10 is N + 1, the difference in the number of teeth is 1. Therefore, each time the input shaft 1 makes one rotation, the external gears 5a and 5b
It is shifted (rotated) by one tooth with respect to 0.
This means that one rotation of the input shaft 1 is -1 / of the external gears 5a, 5b.
It means that the rotation has been reduced to N rotations.

The rotation of the external gears 5a and 5b is absorbed by the gap between the inner roller holes 6a and 6b and the inner pin 7 (inner roller 8), and only the rotation component is reduced.
To the output shaft 2.

As a result, a speed reduction of -1 / N is achieved.

The above-mentioned internal meshing planetary gear structure is currently applied to various reduction gears or speed-up gears. For example,
In the above structure, the first shaft is used as the input shaft, the second shaft is used as the output shaft, and the internal gear is fixed.
The first shaft is an input shaft, the internal gear is an output shaft, and the second shaft is
The reduction gear can also be configured by fixing the shaft. Further, in these structures, by reversing the input and output shafts, a "speed increasing device" can be formed.

FIG. 6 shows an example in which the above structure is a unit type. (JP-A-62-2043).

In this structure, the output shaft 2 is attached to a mating machine via a bolt hole 14, but the internal meshing planetary gear structure itself is the same as that shown in FIGS. Therefore, members having the same functions as those in FIGS. 4 and 5 are denoted by the same reference numerals. The internal meshing planetary gear structure is also used in such types of speed reducers and speed-increasing gears.

In the speed reducer described above with reference to FIGS. 4, 5 and 6, the inner pin 7 is cantilevered by the output shaft 2 side flange (second shaft side flange) 2a as described above. For example, Japanese Utility Model Publication No. 31-9414, U.S. Pat.
0523 and JP-B-56-3551 disclose a speed reducer in which inner pins are supported at both ends in order to increase the rigidity and strength of the device.

[0017]

However, in JP-B-56-35551, one end of the inner pin is fitted into a flange near the output shaft, and the other end is supported by a flange or a ring with an interference. There is a problem that it is difficult to disassemble and assemble due to the tight fit.

In Japanese Utility Model Publication No. 31-9414 and U.S. Pat. No. 3,403,523, one end of the inner pin is similarly fitted into a flange near the output shaft, but the other end is fastened to the flange by a bolt. Since it is necessary to further process the inner pins to form bolts and tapped holes, the positional accuracy of the inner pins after assembling may be reduced, and the manufacturing cost may be increased.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and therefore, the trochoid tooth profile supported on the inner pin at both ends thereof has a high positional accuracy of the inner pin and can be easily disassembled and assembled. It is an object to provide an inscribed planetary gear structure.

[0020]

SUMMARY OF THE INVENTION The present invention provides a first shaft, an eccentric body which is rotated by rotation of the first shaft, and external teeth which are attached to the eccentric body via a bearing and which are capable of eccentric rotation. A gear, an internal gear internally meshed with the external gear, an internal roller hole provided in the external gear, an internal pin loosely fitted in the internal roller hole, and one end of the internal pin are connected. A second shaft to which only the rotation component of the external gear is transmitted, and a trochoid-type inscribed planetary gear structure including: a second shaft that is opposite to the second shaft across the external gear; has little inner pin holes of larger diameter than the diameter of the pin, and the inner pin support plate rotatable about said first axis is arranged, the inner pin supported
The holding plate has a slit extending radially from its peripheral end.
The first peripheral portion on the external gear side divided in the thickness direction
A toothed gear and a second peripheral edge on the opposite side are formed.
The other end of the inner pin is provided at the first peripheral edge and the second peripheral edge.
First and second inner pin holes to be inserted are formed respectively
And penetrates the second peripheral portion and is screwed into the first peripheral portion.
Bolts to reduce the distance between the slits
By the so that attached to down supporting plate is obtained by solving the above problems.

[0021]

According to the present invention, in the trochoid toothed inscribed type planetary gear structure, the first inner pin hole is formed to have a diameter substantially matching the diameter of the inner pin, and the second inner pin hole is formed to have a diameter of the inner pin. The above problem is solved more reliably by being formed with a slightly larger diameter.

[0023]

According to the present invention, the inner pin support plate is provided on the outer side of the external gear (on the side opposite to the second axis with the external gear therebetween) and is rotatable about the first axis. The other end of the inner pin, one end of which is fixed, is inserted into the pin hole, and in this state, the inner pin support plate is bent by the tightening means to be displaced. Specifically, slide the other end of the inner pin
The first and second peripheral parts divided by
The second inner pin hole and the second inner pin hole
Tighten with bolts that penetrate the periphery and accumulate in the first periphery
By doing so, the first peripheral portion and the second peripheral portion
At least one is bent. As a result, the first
At least one of the inner pin hole and the second inner pin hole is
Contact with the other end of the
The contact strength by adjusting the width of the bolt with bolts
It is possible to easily and securely connect the other end
It can support and fix and adjust its supporting force.
You can also. In addition, the bolt is located outside (the second peripheral portion).
Side) can be tightened and removed from the
Decomposition can also be easily performed. In addition, the inner pin can be easily and reliably fixed at both ends with a simple configuration, and the positional accuracy of the inner pin can be improved since the inner pin itself is not screwed.

[0024]

[0025]

[0026] The above and substantially the same as the outer diameter of the pore diameter of the inner pin in the first pin hole, if so set in somewhat larger than the outer diameter of the inner pin it second inner pin holes, first Since the position of the inner pin can be regulated by the peripheral portion and the other end of the inner pin can be supported and fixed by the first peripheral portion, the positional accuracy of the inner pin can be further improved.

[0027]

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

FIG. 1 is a cross-sectional view corresponding to FIG. 6, showing an example in which a trochoid-type inscribed planetary gear structure according to an embodiment of the present invention is applied to a unit type speed reducer.

The basic configuration of the trochoid toothed inscribed planetary gear structure of this embodiment is the same as that of FIG. 6 except that the three external gears 5a, 5b, and 5c are used to increase the rotational balance.
Are common to those shown in (1) and (2), and the same reference numerals are given to common portions, and description thereof will be omitted.

In this embodiment, one side (one end) of the inner pin 7 is fixed to the output shaft flange (second shaft side flange) 2a by interference fitting, and the other side (the other end) is the external gear 5a. And is supported by an inner pin support plate 20 disposed outside.

The inner pin support plate 20 is rotatably mounted on the input shaft 1 via a bearing 21. The inner pin support plate 20 has a first portion divided in a thickness direction by a circumferentially extending slit 22 at an outer peripheral portion thereof. A peripheral portion 23a and a second peripheral portion 23b are formed. The first peripheral portion 23a is connected to the second peripheral portion 23a.
It is formed slightly thicker than b. Further, the bearing 21 need not be provided.

As shown in the plan view of FIG. 2 as viewed from the right side of FIG. 1, the inner pin support plate 20 has first inner pin portions 23a and 23b on the outer peripheral portion, respectively. Hole 2
4a and a second inner pin hole 24b are formed, a screw hole 25a is formed in the first peripheral portion 23a, and a bolt hole 25b and a tap hole 25c subsequent thereto are formed in the second peripheral portion 23b.

The diameter of the first inner pin hole 24a is substantially equal to the outer diameter of the inner pin 7, and the diameter of the second inner pin hole 24b is slightly larger than the outer diameter of the inner pin 7. .

The bolt holes 25b and the tap holes 25c
As shown in FIG.
Is penetrated, and the tip end portion is inserted into the screw hole 25a.

The other end of the inner pin 7 is fitted into the first inner pin hole 24a and the second inner pin hole 24b.
It is fixed by tightening the bolt 26 to bend the second peripheral portion 23b inward.

Next, this fixing method will be specifically described with reference to FIG.

FIG. 3A is an enlarged view showing a state before fixing the inner pin 7 inserted in the first inner pin hole 24a and the second inner pin hole 24b, and FIG. This shows a state after the pin 7 is fixed.

As shown in FIG. 3A, the diameter of the first inner pin hole 24a is within a range in which the inner pin 7 can slide.
However, the hole diameter of the second inner pin hole 24b is slightly larger than the outer diameter of the inner pin 7, and the inner pin is in a loose fit state.

As described above, the second peripheral portion 23b is slightly thinner than the first peripheral portion 23a and is easily bent.

Therefore, when the bolt 26 is tightened, the second peripheral portion 23b mainly bends inward, and the state shown in FIG. 3B is easily formed.

In the state of FIG. 3B, the second peripheral portion 2
Since the second inner pin hole 24b is displaced by the deflection of the inner pin 7b, a part of the hole wall of the second inner pin hole 24b comes into contact with the inner pin 7, so that the inner pin 7 is securely held. Fixed.

At this time, the first peripheral portion 23a is thicker than the second peripheral portion 23b and hardly bends because the first inner pin hole 24a is almost in close contact with the inner pin 7. It functions to position the pin 7.

As described above, according to the present embodiment, the inner pin 7
Since the other end of the inner pin 7 can be easily and surely fixed at an accurate position, it has a simple structure, but easily supports the inner pin 7 with high positional accuracy.

Accordingly, it is possible to easily form a trochoid-type inscribed planetary gear structure having high rigidity and strength.

Further, since the bolt 26 can be operated from the outside with the input side casing 12 removed, the assembly and disassembly are easy. Further, by adjusting the tightening degree of the bolt 26 and adjusting the width of the slit 22, the supporting force for the inner pin 7 can be appropriately adjusted.

Accordingly, the trochoid-type inscribed planetary gear structure of this embodiment is particularly effective as a reduction gear for a robot joint, for example, which requires a unit type reduction gear and high rigidity.

Although the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and can be variously modified without departing from the gist thereof.

[0048]

For example, the first peripheral edge and the second peripheral edge may be secured in precise positions by flexing substantially equal amounts.

The number of external gears is not limited to three, but may be one or two, or in some cases four or more.

Further, the trochoid-type inscribed planetary gear structure is not limited to the one applied to the speed reducer, and may be applied to the speed increaser with the input shaft and the output shaft being reversed. It is not limited to the unit type.

[0052]

As described above, according to the present invention, the other end of the inner pin is fitted and fixed to the inner pin hole of the inner pin support plate disposed outside the external gear. Although the structure is simple, the inner pin can be easily and accurately supported at both ends. Therefore, the trochoid-type inscribed planetary gear structure having high rigidity and strength can be easily formed, and the excellent effect that the disassembly and assembly can be easily performed can be obtained.

Further, a first peripheral edge and a second peripheral edge are formed in the outer peripheral portion of the inner pin support plate having the inner pin hole by slits in the thickness direction, and these first peripheral edge portions are formed by bolts. And at least one of the second peripheral portions is bent.
An excellent effect that the inner pin can be securely fixed by the inner pin hole is also obtained.

Further, the diameter of the first inner pin hole in the first peripheral portion is substantially equal to the outer diameter of the inner pin, the hole diameter of the second peripheral portion is slightly larger than the outer diameter of the inner pin, and the second peripheral portion is When the inner pin is mainly bent, the inner pin can be positioned at the first peripheral edge and the inner pin can be fixed at the second peripheral edge, thereby supporting the inner pin with higher positional accuracy. An excellent effect of troweling can also be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a trochoid-type inscribed planetary gear structure of an embodiment.

FIG. 2 is a plan view showing an inner pin support plate applied to the trochoid toothed inscribed planetary gear structure.

FIG. 3 is an enlarged partial sectional view showing the operation of the embodiment.

FIG. 4 is a cross-sectional view showing a speed reducer to which a conventional double-row internal meshing planetary gear structure is applied.

FIG. 5 is a sectional view taken along the line IV-IV in FIG. 3;

FIG. 6 is a sectional view showing an example in which a conventional double-row internal meshing planetary gear structure is applied to another speed reducer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input shaft, 2 ... Output shaft, 3a, 3b, 3c ... Eccentric body, 4a, 4b, 4c ... Bearing, 5a, 5b, 5c ... External gear, 7 ... Inner pin, 8 ... Inner roller, 10 ... Inner Tooth gear, 11 ... outer pin, 20 ... inner pin support plate, 22 ... slit, 23a 23b ... peripheral part, 24a, 24b ... inner pin hole, 26 ... bolt.

Claims (2)

(57) [Claims] A first shaft, an eccentric body which is rotated by rotation of the first shaft, an external gear which is mounted on the eccentric body via a bearing, and which is capable of eccentric rotation; An internal gear internally meshed with the internal gear, an internal roller hole provided in the external gear, an internal pin loosely fitted in the internal roller hole, and one end of the internal pin are connected, and a rotation component of the external gear is provided. A trochoid-type inscribed planetary gear structure comprising: a second shaft to which only the shaft is transmitted; and a second shaft having a diameter slightly larger than the diameter of the inner pin on a side opposite to the second shaft with the external gear interposed therebetween. It has an inner pin holes, and the inner pin support plate rotatable about said first axis is arranged, the inner
The pin support plate has a slit extending radially from its peripheral end.
First peripheral edge on the external gear side divided in the thickness direction by the
And the second peripheral edge opposite to the external gear are formed.
, These a first peripheral portion to the second peripheral portion and the other end portion of the inner pin
The first inner pin hole and the second inner pin hole into which
And penetrates the second peripheral portion and is screwed into the first peripheral portion
Bolts that reduce the spacing between the slits
A trochoid-type inscribed planetary gear structure mounted on a pin support plate . 2. The method according to claim 1, wherein the first inner pin hole has a diameter substantially equal to the diameter of the inner pin, and the second inner pin hole has a diameter slightly larger than the diameter of the inner pin. Features a trochoid tooth profile inscribed planetary gear structure.