JP2888673B2 - Inner mesh 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 reduction gear or a speed-increasing gear, and more particularly to an internally meshing planetary gear structure suitable for being applied to a reduction gear or a speed-increasing gear which is required to have a small size and a high output. .

[0002]

2. Description of the Related Art Conventionally, a first shaft, an external gear mounted eccentrically with respect to the first shaft via an eccentric body provided on the first shaft, and the external gear There is widely known an internally meshing planetary gear structure having an internal gear internally meshed with a second shaft connected to the external gear via means for transmitting only the rotation component of the external gear. Have been.

FIGS. 6 and 7 show a conventional example of this structure.
In this conventional example, the first shaft is used as an input shaft, the second shaft is used as an output shaft, and the above structure is applied to a "reduction gear" by 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 integrated. Two external gears 5a, 5b are mounted on the respective eccentric bodies 3a, 3b via bearings 4a, 4b. This external gear 5
a, 5b are provided with a plurality of inner roller holes 6;
And the inner roller 8 is fitted.

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.

[0006] On the outer periphery of the external gears 5a and 5b, external teeth 9 such as a trochoid tooth shape and an arc tooth shape are provided. 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 and 5b is fixed or fitted to the flange portion 14 of the output shaft 2.

When the input shaft 1 makes one rotation, the eccentric bodies 3a, 3b
Makes one revolution. By one rotation of the eccentric bodies 3a and 3b,
The external gears 5a and 5b also try to oscillate around the input shaft 1, but their rotation is restricted by the internal gear 10, so that the external gears 5a and 5b Mostly only swinging 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 rotates, the external gears 5 a and 5 b are connected to the internal gear 1 fixed to the casing 12.
It is shifted (rotated) by one tooth with respect to 0.
This means that one rotation of the input shaft 1 has been reduced to -1 / N rotation of the external gear.

The rotation of the external gears 5a and 5b is absorbed by the gap between the inner roller hole 6 and the inner pin 7, and only the rotation component is transmitted to the output shaft 2 via the inner pin 7. You.

Here, the inner roller holes 6a and 6b and the inner pin 7 (inner roller 8) form a "constant speed internal gear mechanism".

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

In this conventional example, the internal gear of the internal meshing planetary gear structure is fixed, the first shaft is used as the input shaft, and the second shaft is used as the output shaft. The reduction gear can also be configured by using one shaft as the input shaft and the internal gear as the output shaft. Further, by inverting these inputs and outputs, it is also possible to configure a gearbox.

However, such a conventional speed reducer supports the output shaft 2 against load fluctuations occurring in the speed reduction mechanism and external radial loads acting on the output shaft 2 from a partner machine, as is apparent from FIG. A pair of bearings 15a, 15b
In order to increase the stability of the support, it is generally necessary to make the Y section in FIG. 6 longer and the X section as short as possible.

However, since it is difficult to shorten the X section, the Y section must be necessarily lengthened, and as a result, there is a problem in that the axial length of the speed reducer increases.

Therefore, as shown in FIG. 8, "steps" 71 and screws 72 are provided at both ends of the inner pin 7A, and an annular support ring 17A is formed integrally with the input shaft 1A. There has also been proposed a configuration in which the flange portion 14A of the output shaft 2A is connected and fixed using a nut 73, and the speed reduction mechanism is disposed between the flange portion 14A of the output shaft 2A and the support ring 17A (see FIG. 1). 31-32
9414).

[0017]

However, in such a support structure, a step and a screw are provided on the inner pin which requires high hardness and high accuracy, and the inner pin is screwed into the input shaft and is fitted into the flange portion so as to be fitted into the nut. Because it was a structure to tighten
Not only is the accuracy of machining and assembling difficult, but also the cost is extremely high.Moreover, stress is concentrated on the stepped part, so that the effect of the double-sided structure is diminished. For this reason, there is a problem that the structure is extremely complicated, such as necessitating another contrivance, and the actual situation is that the structure does not reach the known structures shown in FIGS.

The present invention has been made in view of such a conventional problem, and has a simple structure and a low cost while adopting a double-sided structure, and does not cause problems such as stress concentration and is durable. It is an object of the present invention to provide an internally meshing planetary gear structure having excellent characteristics.

[0019]

According to the present invention, there is provided an external gear having a first shaft and an eccentric member provided on the first shaft, the external gear being mounted eccentrically rotatable with respect to the first shaft. And an internal gear in which the external gear is internally meshed, and a second shaft connected to the external gear via means for transmitting only the rotation component of the external gear, and As means for transmitting the rotation component, an inner pin that can constitute a constant-speed internal gear mechanism with respect to the internal pin hole provided in the external gear is fixed at one end to a flange portion formed on the second shaft. In an internally meshing planetary gear structure in which the other end sandwiching the external gear is fixed to an annular support ring, both the annular support ring and the flange portion of the second shaft are connected by a pair. It is supported at both ends by a casing via a bearing, and the flange, the support ring, and The positioning of the inner pin in the axial direction, off
Either the flange, the support ring, or both ends of the inner pin
The above-mentioned problem has been solved by sandwiching one of the two members by either the inner ring or the outer ring of the pair of bearings.

Further, the present invention provides a first shaft, an external gear mounted eccentrically rotatable with respect to the first shaft through an eccentric body provided on the first shaft, An internal gear in which the tooth gear is internally meshed, and a second shaft connected to the external gear via means for transmitting only the rotation component of the external gear, and transmitting the rotation component. Means for forming an equal-speed internal gear mechanism with respect to the internal roller hole provided in the external gear, and an internal roller penetrating the internal roller and having one end fixed to a flange portion formed on the second shaft. And an inner pin having the other end sandwiching the external gear fixed to the annular support ring, wherein the annular support ring and the flange portion of the second shaft are provided. Both are supported by the casing via a pair of bearings, and
The axial positioning of the flange portion, the support ring, and the inner pin is performed by positioning both ends of the flange portion, the support ring, and the inner pin.
The above-mentioned problem has also been solved by sandwiching one of the two members between the inner ring and the outer ring of the pair of bearings.

Preferably, the positioning of the flange, the support ring, and the inner pin in the axial direction is performed by sandwiching both ends of the inner pin between the inner rings of the pair of bearings.

[0022]

According to the present invention, the inner pin penetrating the external gear is supported by the flange portion of the second shaft and the annular support ring, and both the support ring and the flange portion are connected via a pair of bearings. To support both sides of the casing. As a result, the rigidity and stability of the speed reduction mechanism can be significantly improved while shortening the axial length of the entire speed increaser / reducer.

In positioning the flange portion, the inner pin and the support ring in the axial direction, the flange portion,
One of the two ends of the support ring and the inner pin
Since the portions are sandwiched between the inner rings (or the outer rings) of the pair of bearings, the axial positioning, particularly the positioning of the inner pins, can be reliably performed without providing a special member.

In the present invention, the inner pin is fixed to the second shaft and the support ring, and does not rotate by itself. However, since the shape of the inner pin is a simple cylinder,
High-precision machining can be easily performed with a hard material, and a pair of bearings are used to support both sides of the deceleration mechanism, so the overall rigidity can be greatly increased and the inner pin is supported in an extremely stable state From what you can do,
The inner roller can be omitted. However, if cost is acceptable, it is of course better to cover the outer circumference of the inner pin with a conventional inner roller so that the constant-speed internal gear mechanism with the external gear functions more smoothly. .

If the "ends of the inner pin" is sandwiched between the pair of bearings, the axial position of the flange, the support ring, and the inner pin is specified, and the axial position between the members is specified, particularly The distance between the two bearings can be specified accurately and easily.

Further, when the both ends of the inner pin are sandwiched between the inner rings of the bearing, the flange portion of the second shaft, the inner ring of both bearings, the inner pin, and the support ring are connected without any relative rotation. Therefore, the rigidity can be improved accordingly, and the rigidity can be favorably maintained for a long period of time.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a speed reducer to which an internally meshing planetary gear structure according to the present invention is applied, and FIG.
FIG. 2 is a sectional view taken along line II.

In the following description, the same or similar parts as those of the conventional example shown in FIGS.
The digits are given the same number.

One end of the inner pin 107 is fitted (press-fitted) into the flange portion 114 of the output shaft 102. A support ring 117 is fitted (press-fitted) into the other end of the inner pin 107.

The flange portion 114, the inner pin 107, and the support ring 117 are supported on the casing 112 by a pair of bearings 115a and 115b. The total length of all the inner pins (eight in this example) 107 is set to be the same, and the bearings 115a and 115b are incorporated so that the total length matches the distance between the bearings 115a and 115b. That is, the positioning of the inner pin 107 (and thus the flange 114 and the support ring 117 fixed thereto) in the axial direction is performed by the pair of bearings 115a and 115b.

More specifically, as shown in FIG. 2, the inner pin 107 has an inscribed circle diameter D1 of the bearings 115a, 115.
b is smaller than the inner ring outer diameter d1 and the circumscribed circle diameter D2
Are set to be smaller than the outer ring inner diameter d2 of the bearings 115a and 115b. As a result, the inner pin 107
The bearings 115a and 115b are positioned only by the inner rings 124a and 124b. As a result, the support ring 1
17, inner rings 124a, 124 of bearings 115a, 115b
b, the inner pin 107, and the flange portion 114 do not rotate at all, so that a strong rigid body can be formed, and the durability of the rigid body can be maintained for a long period of time.

In this embodiment, the inner pin 107 itself does not rotate, but since its shape is extremely simple unlike the conventional one, it is possible to easily perform high-precision processing with a hard material. Sufficient quality can be ensured without rollers, and cost reduction can be realized.

According to the present invention, the inner pin 107 is supported at both ends by the flange portion 114 supported by the casing via the bearing 115b and the support ring 117 supported by the casing via the bearing 115a. Therefore, this can be realized only when the inner pin 107 has an extremely stable structure (with respect to an external radial load).

Reference numeral 130 in the drawing is a retaining ring for ensuring the connection of the bearing 115a, and complements the connection by press-fitting the flange portion 114 and the inner pin 107.

Next, the operation of the speed reducer will be described.

The external gears 105a and 105b are connected to the input shaft 10
The input shaft 101 is rotated by the rotation of the external gear 111a and the external gears 105a and 105b, which correspond to the internal teeth of the internal gear 110.
The decelerated rotation (rotation) of 105b is exactly the same as in the conventional known example. These external gears 105a, 10
Rotation of 5b is achieved by rotating inner pin holes 106ap and 106bp and inner pin 1
The swing component is absorbed by the gap between the inner shaft 107 and the rotation component, and only the rotation component is transmitted to the flange 114 of the output shaft 102 via the inner pin 107. At this time, the support ring 117
The function of equalizing the load of each inner pin 107 is achieved.

An external radial load acting on the output shaft 102 is applied to the bearing 115a and the bearing 1 (via the inner pin 107).
15b. The inner pin 107 has a simple shape with no steps or screws, but has axial bearings 115a, 115
Since the inner rings 124a and 124b of b are present and sandwiched therebetween, they do not come off in either direction of the input shaft side or the output shaft side.

In the above embodiment, the fixed inner pin 107 is used to fix the inner pin hole 106a of the external gear.
A constant-speed internal gear mechanism with p and 106 bp was configured,
In order to more smoothly bring out the function of the constant-speed internal gear mechanism, it is more preferable to cover the outer periphery of the inner pin with the inner roller 108 as in the related art.

This example is shown in FIG. 3 and FIG. This embodiment is the same as the previous embodiment except that the inner pin 107 is covered with the inner roller 108 and the inner roller holes 106a and 106b form a constant speed internal gear mechanism. In the drawings, the same portions will be denoted by the same reference numerals, without redundant description. According to this embodiment, since the slip between the inner pin 107 and the inner roller holes 106a and 106b can be favorably absorbed by the inner roller 108, a reduction gear with higher efficiency and excellent durability can be obtained. .

[0041] In the above SL embodiment, the inner pin 107 is passed through, press-fitted flange portion 114 and the support ring 117, a pair of bearings 115a and both ends of the inner pins 107,
In the present invention, the inner pin 107 does not necessarily need to be penetrated. For example, a hole 130 having a finite depth is formed in the flange 114 or the support ring 117 as shown in FIG. This hole 13
The inner pin 107 is driven until it comes into contact with the bottom portion 131 of the first ring, and the positioning itself is performed by using a pair of bearings 115a and 115 with the flange 114 or a part of the support ring 117.
It may be performed by sandwiching between b.

[0042]

As described above, according to the present invention,
Since the speed reduction mechanism is supported at both ends by a pair of bearings, the overall length of the speed reducer can be reduced. Further, since the positioning of the inner pin in the axial direction is performed by the pair of bearings, the number of parts and the number of assembly steps can be reduced. Furthermore, since the shape of the inner pin itself is simple, high-precision processing with a hard material can be easily and at low cost, and the inner pin itself is supported by both ends so that it is stable against the outer radial. Coupled with the retention, expensive inner rollers can be omitted (without deteriorating quality or durability) for some applications. In this case, when the inner roller is provided, the quality can be further improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a speed reducer to which an internally meshing planetary gear structure according to the present invention is applied.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view of a speed reducer according to another embodiment of the present invention.

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

FIG. 5 is a partial cross-sectional view showing another example of a connection state between a flange portion, a support ring, and an inner pin.

FIG. 6 is a sectional view showing a basic reduction gear to which a conventional internal meshing planetary gear structure is applied.

FIG. 7 is a sectional view taken along line VII-VII in FIG. 6;

FIG. 8 is a cross-sectional view showing another example of the speed reducer to which the conventional internal meshing planetary gear structure is applied.

[Explanation of symbols]

 1, 101: input shaft, 2, 102: output shaft, 3a, 3b, 103a, 103b: eccentric body, 5a, 5b, 105a, 105b: external gear, 6a, 6b, 106a, 106b: inner roller hole, 106ap , 106 bp: inner pin hole, 7, 107: inner pin, 8, 108: inner roller, 10, 110: internal gear, 11, 111: outer pin, 14: 114: flange portion of output shaft, 15a, 15b, 115a, 115b ... bearing, 17, 117 ... support ring, 124a, 124b ... inner ring, 125a, 125b ... outer ring.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-229139 (JP, A) JP-A-62-161026 (JP, U) JP-A-1-96552 (JP, U) JP-A-3-96 148 (JP, U) Japanese Utility Model Showa 56-65725 (JP, U) Japanese Utility Model Showa 56-937 (JP, U) Japanese Utility Model Showa 60-23344 (JP, U) Japanese Patent Publication No. 46-29082 (JP, B1) (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 1/32

Claims (3)

(57) [Claims] 1. An external gear mounted eccentrically rotatable with respect to a first shaft, an eccentric body provided on the first shaft, and an internal gear, wherein the external gear is an internal gear. An internal gear that is in mesh with the second gear, and a second shaft connected to the external gear through a unit that transmits only the rotation component of the external gear, and as a unit that transmits the rotation component, An inner pin, which can constitute a constant-speed internal gear mechanism with respect to the internal pin hole provided in the external gear, is fixed at one end to a flange formed on the second shaft, and sandwiches the external gear. In an internally meshing planetary gear structure in which the other end is fixed to an annular support ring, both the annular support ring and the flange portion of the second shaft are supported by a casing via a pair of bearings. Support and axial positioning of the flange, support ring, and inner pin The flange, support ring, both ends of the inner pin
Characterized in that a part of any two of them is sandwiched by either the inner ring or the outer ring of the pair of bearings. 2. An external gear mounted eccentrically with respect to the first shaft via an eccentric body provided on the first shaft and an eccentric body provided on the first shaft. An internal gear that is in mesh with the second gear, and a second shaft connected to the external gear through a unit that transmits only the rotation component of the external gear, and as a unit that transmits the rotation component, An inner roller that can form a constant-speed internal gear mechanism with respect to an internal roller hole provided in the external gear; an external roller that penetrates the internal roller and has one end fixed to a flange portion formed on the second shaft; And an inner pin having the other end sandwiching the gear fixed to the annular support ring, wherein both the annular support ring and the flange portion of the second shaft are paired. Supported on the casing via a bearing, and the flange portion, the support ring, and The axial positioning of the inner pin is determined by the flange, support ring, and both ends of the inner pin.
Characterized in that a part of any two of them is sandwiched by either the inner ring or the outer ring of the pair of bearings. 3. The axial positioning of the flange, the support ring, and the inner pin according to claim 1, wherein both ends of the inner pin are sandwiched between inner rings of the pair of bearings. An internally meshing planetary gear structure characterized by the following.