JP2000249199A - Inner roller and outer roller of internal engagement planetary gear structure and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce angle backlash, enhance resistance against overload, and transmit large load by setting the longitudinal sections of the internal circumferential wall and outer circumferential wall of a cylinder to barrel shapes having the inside/outside diameters in the axial central parts larger than the inside/outside diameters in the both end parts. SOLUTION: In a longitudinal section of an internal circumferential wall 32 of a cylinder, an inner roller 30 has the inside diameter d1 in the axial central part set larger than the inside diameter d2 in the both end parts and the central part P1 of a through hole 31 has a projecting barrel shape. The projection of the internal circumferential wall and the recess of the both end parts P2 in the central part P1 are smoothly continued and the recess and the both end faces are also smoothly continued. As for the longitudinal section of the outer circumferential wall 33 of the cylinder, the outside diameter D1 in the axial center part is larger than the outside diameter D2 of the both end parts and the central part P1 of the through hole 31 has a projecting barrel shape. This constitution can sufficiently secure lubricant oil in a clearance in the internal circumferential wall 32, hold the inner pin coaxial with the inner roller without causing any rattling, and eliminate edge abutment with an external tooth gear so as to transmit large load.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner roller or an outer roller having an internally meshing planetary gear structure, and a method of manufacturing these rollers.

[0002]

2. Description of the Related Art Conventionally, a first shaft, an eccentric body that rotates by rotation of the first shaft, and an external gear that is incorporated so as to be eccentrically rotatable with respect to the first shaft via the eccentric body. An internally meshing planet, comprising: an internal gear in which the external gear internally meshes; and a second shaft connected to the external gear via means for transmitting only the rotation component of the external gear. Gear structures are widely known.

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, 3b are fitted. The eccentric bodies 3a and 3b are integrated. Two external gears 5a, 5b are attached to 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 inserted.

The reason why the inner pin 7 is covered with the inner roller 8 is to disperse the slip during operation (the inner pin 7 and the external gear 5).
This is for dispersing the slips of the inner pin 7 and the inner roller 8 and the slip of the inner roller 8 and the external gears 5a and 5b.

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

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.

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.

The internal teeth of the internal gear 10 are specifically the external pins 1
1. Outer pin 11 is outer pin hole 13
And is held so as to rotate easily. In addition, as shown in FIG. 8, for example, the outer pin 11 is sometimes covered with an outer roller 14. As a result, the sliding during operation is dispersed (the sliding between the outer pin 11 and the outer pin hole 13 in FIG. 6 is replaced with the outer pin 11A and the outer roller 1 as shown in FIG. 8).
4 and the outer pin 11A and the outer pin hole 13).

The operation of the speed reducer will be briefly described. When the input shaft 1 makes one rotation, the eccentric bodies 3a and 3b make one rotation. When the eccentric bodies 3a and 3b make one rotation, the external gears 5a and 5b also try to swing and rotate around the input shaft 1. However, since the rotation is restricted by the internal gear 10, the external gears 5 a and 5 b almost only oscillate while being in contact with the internal gear 10.

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, for example, 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 the rotation of the input shaft 1 has been reduced to the rotation of -1 / N of the external gear. In addition, a minus sign means reverse rotation.

The rotation of the external gears 5a and 5b is absorbed by the gap between the inner roller hole 6 and the inner roller 8 so that only the rotation component is output through the inner pin 7 in the inner roller 8 to the output shaft. 2 is transmitted. As a result, the reduction ratio -N
Deceleration is achieved.

Therefore, by combining the speed reducer having the internal meshing planetary gear structure with, for example, a motor, a geared motor having a large reduction ratio can be obtained with only one speed reduction mechanism.

In this conventional example, the internal gear of the internal meshing planetary gear structure is fixed, and 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, it is also possible to configure a speed increaser by reversing these inputs and outputs.

Further, in this conventional example, the eccentric body is directly incorporated on the outer periphery of the first shaft.
There is also known a type in which eccentric bodies are incorporated in the dispersed first shafts, and the external gear is oscillated and rotated via the eccentric bodies. The present invention can be applied without any problem even to this type of internally meshing planetary gear structure.

[0016]

As shown exaggeratedly in FIG. 9, a gap δ1 is provided between the outer circumference of the inner pin 7 and the inner circumference of the inner roller 8. As shown exaggeratedly in FIG. 10, a gap δ2 is provided between the outer circumference of the outer pin 11A and the inner circumference of the outer roller 14. This gap δ1
, Δ2 are to ensure a lubricating oil film between the two members and to allow the members in contact with each other to slide smoothly.

However, if such gaps δ1 and δ2 are provided, the inner pin 7 and the inner roller 8 or the outer pin 11A
This causes a problem that play occurs between the outer gear 14 and the outer roller 14, and as a result, play occurs in the entire gear transmission mechanism. Therefore, there is a disadvantage that the rotation on the driving side does not immediately appear as the rotation on the driven side when the rotation from one side to the other side is changed. Such a response delay is hereinafter referred to as “angle backlash”.

This angle backlash reduces control accuracy when the inscribed planetary gear structure is used as a control mechanism with a servomotor such as a joint drive reduction gear of an industrial robot. Becomes There are various possible causes for the occurrence of angle backlash in the internal meshing planetary gear structure. As a device for eliminating such angle backlash, conventionally, for example, external gears, internal gears and the like are used for forward rotation and reverse rotation. Various structures are known, such as splitting or sharing roles for normal rotation and reverse rotation (Japanese Patent Application Laid-Open Nos. 59-106744 and 59-106744).
113340, JP-A-59-115743, JP-A-59-208366, etc.).

As a method of minimizing the gap between the outer pin and the outer pin hole (in the type of the internally meshing planetary gear having no outer roller), the applicant has disclosed Japanese Patent Application No. 60-86571. Japanese Patent Publication No. 5-86506).

However, in any of the above-mentioned known examples, the ones that focus on the gap δ1 between the inner pin and the inner roller and the gap δ2 between the outer pin and the outer roller in order to reduce the angle backlash have been described. In fact, no measures have been taken for the angle backlash that occurs here.

The reason is that a predetermined lubricating oil must always be ensured between the inner pin and the inner roller or between the outer pin and the outer roller; for example, a processing error, an assembly error, or each member during power transmission. Of the inner pin and the inner roller or the state where the axis of the outer pin and the outer roller are displaced due to the deformation of the two members, it is necessary to smoothly slide the two members; Is considered to be a configuration that cannot be eliminated (essential configuration).

As a method of ensuring good sliding of the two sliding members without providing a gap, it is conceivable to use a material having low friction and good familiarity, such as white metal or fluororesin. However, since the inner roller and the outer roller of the internal meshing planetary gear structure are generally subjected to a large torque, which is obtained by amplifying the torque of the input shaft from several times to 100 times or more, from the viewpoint of durability, high hardness and high strength are required. Material (for example, high carbon chromium bearing steel (JIS G4
805 SUJ2 or equivalent)
Alloy steel for machine structure (JIS G4103, JIS G4
104, JISG4105) by carburizing, quenching and tempering,
A material having a surface hardness of about HRC 58-64) must be used, and this method cannot be adopted in many cases.

It is conceivable to provide a peripheral groove on the inner periphery of the inner roller (or the outer periphery of the inner pin) and secure oil in the peripheral groove. However, this method only increases the processing cost of the inner roller. However, sharp cutouts that cause stress concentration in high-hardness and high-strength materials result in a remarkable reduction in strength, which is not preferable for the configuration of the inner roller and the outer roller of this kind of internal meshing planetary gear structure.

Further, in connection with this, since it is necessary to process a material of high hardness and high strength with high precision, the inner and outer diameters of the inner roller and the outer roller must be processed by "grinding". When the inner diameter is processed by grinding, the finish roughness has a limit (economically 2-3 μ) (since grinding is only processing to shear the crystal grains of the material), and the oil film is maintained with this roughness. In order to achieve a certain amount of clearance δ
In some cases, the existence of δ2 was essential.

However, for such a reason, it is considered that the gap δ1 between the inner pin and the inner roller or the gap δ2 between the outer pin and the outer roller is indispensable in the related art. Therefore, the occurrence of angular backlash due to this is inevitable. It was what was thought to be.

The present invention has been made in view of such a conventional problem, and an inner roller or an outer roller, which has conventionally (naturally) been considered to need to be worked as close to a perfect cylinder as possible. An internally meshing planetary gear that can reconsider the shape of the roller with a new idea, greatly reduce the angle backlash without causing any new inconvenience, and is resistant to overload and can transmit large loads. It is an object to provide an inner roller or an outer roller having a structure.

It is another object of the present invention to provide an optimum method for actually manufacturing the inner roller or the outer roller.

[0028]

According to a first aspect of the present invention, there is provided a first shaft, an eccentric body rotated by rotation of the first shaft, and an eccentric rotation with respect to the first shaft via the eccentric body. An external gear that is incorporated in a possible state, an internal gear in which the external gear meshes internally, and a third gear that is connected to the external gear via a unit that transmits only the rotation component of the external gear. A cylindrical inner roller used together with a cylindrical inner pin to constitute a means for transmitting only the rotation component of an internally meshing planetary gear structure having two shafts. This object is achieved by forming a vertical cross section of the wall into a barrel shape in which the inner and outer diameters of the inner peripheral wall and the outer peripheral wall in the axial center are larger than the inner and outer diameters of both ends.

According to a second aspect of the present invention, a first shaft, an eccentric body rotated by rotation of the first shaft, and an eccentrically rotatable state with respect to the first shaft via the eccentric body are incorporated. An external gear, 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. In the method of manufacturing a cylindrical inner roller used together with a cylindrical inner pin to constitute a means for transmitting only the rotation component of the internal meshing planetary gear structure, the central part of the cylindrical inner roller material is removed. A procedure for forming a cylindrical inner roller material by hollowing out in the axial direction, a procedure for burnishing at least the inner peripheral wall of the inner and outer peripheral walls of the cylindrical inner roller material, and a procedure for burnishing the inner roller material By heat-treating the inner roller material A barrel-shaped formation procedure of deforming the body into a barrel shaped bulged axial central portion, by including one in which the above-mentioned problems are eliminated.

According to a third aspect of the present invention, in the second aspect, the cylindrical shape is formed by the residual strain before the heat treatment and the residual strain due to the heat treatment by more positively applying the processing strain during burnishing. The object has been achieved by forming the longitudinal cross-sectional shape of the peripheral wall and the outer peripheral wall into a clearer barrel shape.

Claims 1, 2, and 3 focus on the inner roller of the internal meshing planetary gear structure. Claims 4, 5, and 6 apply exactly the same configuration to the outer roller.

[0032]

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

The present invention is characterized by the shape of the inner roller and the outer roller of the inner meshing planetary gear structure or the inner and outer peripheral vertical cross sections. The structure of the inner meshing planetary gear structure itself is particularly different from the conventional structure. There is no place. Accordingly, the configuration of the internal meshing planetary gear structure itself has already been described in detail, and the description thereof is omitted.

The longitudinal cross section of the inner roller or the outer roller according to the present invention is such that the inner peripheral wall and the outer peripheral wall are not straight as in the prior art, and the inner and outer diameters of the inner peripheral wall and the outer peripheral wall at the axially central portions are the opposite ends. It has a barrel shape with a diameter larger than the inner and outer diameters.When the inner pin or the outer pin is inserted, oil or grease lubricating oil can be retained here, and the inner pin or Even when the outer pin bends, no one-sided or edge load is caused by the engagement of the external gear.

FIG. 1 is a longitudinal sectional view of the inner roller 30 according to the present invention. Here, the barrel shape is exaggerated.

FIG. 2 is an actual measurement graph obtained by measuring the shape and roughness of the inner peripheral wall of the inner roller 30 according to the embodiment of the present invention with a roughness meter. Here, the scales in the radial direction Y and the axial direction X are not the same for the purpose of measurement, and the magnification in the radial direction Y is set to 200 times the axial direction X.

The line 32L in FIG. 2 corresponds to the inner peripheral wall 32 in the lower half of FIG. That is, the lower part is the entity side, and the upper part is the hollow hole side from the line 32L.

As shown in FIGS. 1 and 2, the inner roller 30 according to this embodiment has a cylindrical inner peripheral wall 32 in which the longitudinal section is not straight, and the inner diameter d1 at the axial center is the inner diameter at both ends. The diameter P is larger than d2 (d1> d2), and the central part P1 of the through hole 31 has a barrel shape that is convex (concave when viewed from the body side). The size of the inner roller 30 according to this embodiment is such that its axial length L1 is 25 mm and the inner diameter d2 at both ends P2 is 1.
The thickness t is 2 mm and the thickness t is 2.5 mm. In this case, the difference (d1-d2) between the inner diameters of the central portion P1 and both ends P2 is about 5 to 6 μm on one side.

The projection 32R1 of the inner peripheral wall at the center portion P1 (concave portion when viewed from the actual side) 32R1 and the concave portion 32R2 at both end portions P2 (projected portion when viewed from the actual side) are smoothly continuous. Both end surfaces 32R3 are also smoothly continuous.

Further, the vertical cross section of the cylindrical outer peripheral wall 33 of the inner roller 30 is not straight, the outer diameter D1 at the axial center is larger than the outer diameter D2 at both ends (D1> D2), and the through hole 31 is formed. Has a convex barrel-shaped central portion P1.

FIG. 3 shows an inner roller 30 according to this embodiment.
FIG. 7 is a conceptual diagram showing a state in which is attached to an inner pin 7. Note that FIG. 3 also gives priority to visibility, so that the radial direction Y and the axial direction X
Are not the same scale.

The outer periphery 7A of the inner pin 7 is in light contact with the (substantially) convex portions 32R2 and 32R2 of the inner peripheral wall 32 of the inner roller 30, and the (substantially) concave portion 32R1 of the central portion P1 of the inner peripheral wall 32 is formed. , That is, (d1-d2) / 2,
As described above (depending on the barrel shape), it is around 5-6 μm. Note that the gap H1 is not so affected by the size of the inner roller 30, and an absolute value of about 2 to 10 μm is an allowable range.

If the gap H1 is too small, the original function of the gap is not exerted. If the gap H1 is too large, a radial (large) force acts between the inner roller 30 and the inner pin 7. But (as seen from the entity side)
Since the arc at the two convex portions 32R2, 32R2 is reduced, and torque is transmitted only at these two points, the inner pin 7 comes into contact with the inner roller 30 only at this portion (at any time), so that the resistance is increased. This is because it is not preferable in terms of abrasion.

By forming the inner peripheral wall 32 of the inner roller 30 in such a shape, the gap H1 in FIG. 3 functions as a space for securing lubricating oil. Further, the inner pin 7 is provided at two convex portions 32R2, 32R2 of the inner peripheral wall 32 of the inner roller 30 by:
Since the inner roller 30 is in contact with the inner roller 30, the center O1 of the inner roller 30 and the inner pin 7 does not shift unless a particularly large force is applied, and basically no "lash" occurs. Therefore, unlike the related art, there is no occurrence of angular backlash due to the gap δ1.

On the other hand, as for the outer circumference 33, since the outer diameter D2 at both ends is smaller than that at the center, the gap σ1, between the inner gear holes 6a, 6b of the external gears 5a, 5b, σ2 is secured. Thereby, when an excessive load is applied to the internal meshing planetary gear structure, the external gears 5a, 5a,
b, the edge contact between the inner rollers 6a and 6b and the inner roller 30 is prevented.

Furthermore, even if there is a processing error or an assembly error, or if each member is elastically deformed at the time of power transmission, an unexpectedly large external load is applied, and the inner pin 7 is bent. Even if it becomes unnecessary, the lubricating oil is secured in the gap H, so that smooth sliding can be maintained.

Therefore, by employing the inner roller (or outer roller) having such a structure, the inner roller (outer roller) and the inner pin can be secured while securing a large amount of lubricating oil, that is, without reducing the durability. By reliably maintaining the coaxiality of the (outer pin), angle backlash can be reduced. Further, even if a processing error, elastic deformation at the time of operation, elastic deformation due to an external load, or the like occurs, good sliding characteristics can be ensured, so that power loss can be significantly reduced.

When the inner roller 30 according to this embodiment is manufactured by a manufacturing method described later, the inner peripheral wall 3
Combined with the fact that the surface of No. 2 is mirror-finished by burnishing, seizure hardly occurs even if the lubricating oil film becomes thin, and according to experiments on actual machines, its power transmission capacity has been greatly improved by about three times. It has been confirmed that noise during operation is also reduced.

Next, a method for manufacturing the inner roller (or outer roller) having such a shape will be specifically described.

In the case of the inner roller having a barrel-shaped inner peripheral wall as described above, a method of cutting the inner peripheral wall by, for example, an ultra-high-precision NC (Nunerical Control) machine tool or the like in a manufacturing process similar to the related art is also considered. Can be However, NC machine tools capable of cutting high-hardness, high-strength materials with high precision are extremely expensive and require a long processing time for each inner roller. However, this cannot be practically realized due to cost.

Therefore, the inventors have combined a so-called burnishing process and a heat treatment, and have devised a manufacturing method in which the processing distortion and the heat treatment distortion are positively utilized.

FIGS. 4A to 4D show the manufacturing method. In addition, each part in FIG. 4 is exaggerated in order to give priority to visibility, and the scales in the radial direction Y and the axial direction X are not the same. The description will be made in the following order.

FIG. 4A First, the outer periphery is machined by a precision lathe at the round bar stage of the inner roller material 30A, and then the machined outer periphery is burnished by a roller burnishing tool 51. The burnishing process here is a process known per se, and is a process of rolling the outer periphery (plastically deforming by crushing).

FIG. 4 (B) Subsequently, in a state before the heat treatment (the material is soft), the central portion of the cylindrical inner roller material 30A is cut out in the axial direction X to cut the cylindrical inner roller material 30B. Then, the inner periphery of the inner roller material 30B is intermediately finished. here,
The inner circumference is to be processed by turning with a precision lathe. This processing is processing by shearing the material structure.

Note that, instead of the processing of FIG.
It is also effective in mass production processing to finish the outer periphery after manufacturing by cold forging plastic processing up to the intermediate finish of (B).

FIG. 4C Next, the entire length of the outer peripheral wall 33 in the axial direction is determined by the chucking device 50.
The inner peripheral wall 32 is burnished by a roller burnishing tool 52 to obtain an inner roller material 30C. The burnishing process here is also known per se, and is a process in which the inner peripheral wall 32 processed by shearing the tissue in FIG. 4B is rolled (in a crushing manner). For this reason, finer roughness (mirror surface) than turning or grinding can be obtained.

FIG. 4 (D) After the inner peripheral wall 32 is burnished in this manner,
FIG. 4D is an exaggerated drawing of the degree of the slight bending after the heat treatment.

When the material of the inner roller material 30C is a high carbon chromium bearing steel material (SUJ2 of JIS G4805 or its equivalent), the heat treatment is preferably a step of hardening the whole by known quenching and tempering. .

The material of the inner roller material 30C is made of alloy steel for machine structure (JIS G4103, JIS G4104,
When it is made of so-called carburized steel such as JIS G4105, it is preferable that the surface is hardened by so-called carburizing quenching and tempering.

In any case, at the time of quenching, since both ends in the axial direction have a large heat dissipation area and are cooled quickly, they shrink more than the central part and solidify in that state. A bent shape as shown is obtained. In FIG. 4 (D), lo represents the bent length at the outer periphery, δo represents the relative contraction amount of the outer diameter, and li and δi represent the bent length and the contraction amount on the inner diameter side, respectively.

That is, as is apparent from the drawing, the outer peripheral side of this inner roller material 30D has δo at both end portions lo.
However, the inner peripheral side has a so-called barrel-shaped shape in which the diameters at both ends in the axial direction are smaller by δi at both ends in the axial direction than at the center.

As described above, in this embodiment, the deformation (thermal strain) caused by the heat treatment is positively used,
A major feature is that the barrel shape of the inner peripheral wall is thereby formed.

Next, a method of forming this barrel shape more positively (larger) will be described with reference to FIG.

In this method, when performing burnishing, the chucking is performed over the entire length in the axial direction in the previous embodiment, but the chucking is intentionally removed at both ends in this embodiment. Things. As a result, when processing pressure is applied from the inner peripheral side by the roller burnishing tool 52 during burnishing, the inner roller material 30E
A phenomenon occurs in which both ends expand outwardly as shown by the broken line in the figure, and the processing (rolling) here becomes lighter, and a state in which the inner peripheral wall 32 is not enlarged only in this portion can be created.

As a result, when the chucking device 50 'is released, as shown in FIG. 5 (B), at the stage where the heat treatment is not yet performed, the barrel shape in which both ends lB are smaller in diameter by δB at both ends lB. The shape can be obtained. Therefore, by applying the above-described heat treatment step to the above, the barrel shape can be made clearer than in the previous embodiment.

In practice, taking into account the size of each inner roller and the applied torque, the actually formed gap H1 (FIG. 3) is 2 to 10 μm (preferably 5 to 6 μm), that is, the crowning amount δo is The method of chucking or heat treatment may be determined so as to be 5 to 15 μm (preferably 7 to 8 μm).

In order to further increase the degree of the barrel shape, in addition to the above-described embodiment, only the center portion is intentionally radiated slowly at the heat radiation stage (both ends are intentionally radiated faster). A heat radiation environment, for example, an environment in which the flow of cooling oil is improved only in the vicinity of both ends at the time of heat radiation may be formed.

According to these methods, for example, when the inner diameter d2 of the inner roller is in the range of 6 mm to 60 mm, the outer diameter (d2 + t) is about 1.3 to 1.7 times (ie, t / t).
If d is in the range of about 1/3 to 1/6, the barrel shape is as intended at the required axial length L1 (about 1.5 to 4 times the inner diameter d2 is required). It has been confirmed by the inventors' tests that the compound can be formed sufficiently. However, ideally, if the outer diameter d2 + t is about 1.5 times (1.4 to 1.6 times) the inner diameter d2 (without performing any further heat treatment or the like), the good gap H1 can be obtained. And the crowning amount δo is secured.

In any case, the outer peripheral surface does not necessarily need to be burnished. Further, the inner and outer circumferences may be finally finished by barrel grinding.

In the inner roller manufactured in this manner, a gap H1 is formed between the inner roller and the inner pin at the axially central portion of the inner peripheral wall, and this serves as a lubricating oil holding portion. Further, since the inner and outer peripheral walls are markedly mirror-finished by burnishing as compared with the conventional grinding, seizure hardly occurs, and the inner and outer peripheral walls are almost always in contact at both ends (the gap between the inner pin and the inner roller is almost zero). ) To eliminate the cause of the angle backlash. In addition, since the inner peripheral wall is mirror-finished, the power transmission efficiency can be kept high by the oil film that is always formed. In addition, since the outer peripheral wall has a barrel shape, the edge contact with the external gear can be prevented. As a result, a larger load transmission (about three times) becomes possible.

In the above embodiment, the configuration and the manufacturing method have been described by taking the inner roller as an example, but it is needless to say that the present invention can be applied to the outer roller in the same manner.

[0072]

As described above, the inner roller (outer roller) according to the present invention, or the inner roller (outer roller) manufactured by the method according to the present invention, has a barrel-shaped gap in its inner peripheral wall. A sufficient amount of lubricating oil can be secured, so that the inner pin (outer pin) can be held coaxially with the inner roller (outer roller) with almost no play.

Since the outer peripheral wall is also barrel-shaped,
Edge contact with the external gear is eliminated, and as a result, a larger load can be transmitted.

Therefore, securing lubricating oil (maintaining durability)
Thus, it is possible to improve power transmission efficiency and transmission capacity, reduce noise, and reduce angle backlash.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an inner roller applied to an internally meshing planetary gear structure according to the present invention.

2 is a graph in which the shape of an inner peripheral wall in a lower half of an inner roller in FIG. 1 is actually measured.

FIG. 3 is a longitudinal sectional view showing a state in which an inner pin is assembled to the inner roller of FIG. 1;

FIG. 4 is a process diagram illustrating a method for manufacturing the inner roller according to FIG. 1;

FIG. 5 is a partial process chart showing a modification of the manufacturing process according to FIG. 4;

FIG. 6 is a partially broken front view for explaining the configuration of a conventional internal meshing planetary gear structure.

FIG. 7 is a sectional view taken along the line VII-VII in FIG. 4;

FIG. 8 is a partially enlarged cross-sectional view illustrating a configuration of an internally meshing planetary gear structure having an outer roller.

FIG. 9 is a cross-sectional view for explaining a relationship between a conventional inner roller and an inner pin.

FIG. 10 is a cross-sectional view for explaining a relationship between a conventional outer roller and an outer pin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Input shaft 3a, 3b ... Eccentric body 5a, 5b ... External gear 6a, 6b ... Inner roller hole 7 ... Inner pin 8, 30 ... Inner roller 10 ... Internal gear 11 ... Outer pin 13 ... Outer pin hole 14 ... Outer roller 32 ... Inner peripheral wall 33 ... Outer peripheral wall 51, 52 ... Roller burnishing tool

Continued on the front page (72) Inventor Kimiaki Nishio 6-1, Asahimachi, Obu City, Aichi Prefecture Sumitomo Heavy Industries Machinery Co., Ltd. Nagoya Works F-term (reference) 3C058 AA01 AA09 AA12 AA14 AA16 AA18 AB04 AB08 BA05 CA01 DA09 3J027 FA13 FA37 FA50 FC12 GC03 GC13 GC22 GC29 GD03 GD08 GD12 GE07 GE25

Claims (6)

[Claims] A first shaft, an eccentric body which is rotated by rotation of the first shaft, an external gear which is eccentrically rotatable with respect to the first shaft via the eccentric body, 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,
A cylindrical inner roller used together with a cylindrical inner pin to constitute a means for transmitting only the rotation component of an internally meshing planetary gear structure provided with: a longitudinal section of an inner peripheral wall and an outer peripheral wall of the cylinder; Wherein the inner peripheral wall and the outer peripheral wall have a barrel shape in which the inner and outer diameters at the axially central portion are larger than the inner and outer diameters at both ends. A first shaft, an eccentric body that is rotated by rotation of the first shaft, an external gear that is incorporated so as to be eccentrically rotatable with respect to the first shaft via the eccentric body, 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,
The method of manufacturing a cylindrical inner roller used together with a cylindrical inner pin to constitute a means for transmitting only the rotation component of the internal meshing planetary gear structure having Forming a cylindrical inner roller material by hollowing out the portion in the axial direction; a step of burnishing at least the inner peripheral wall of the inner and outer peripheral walls of the cylindrical inner roller material; A barrel-shaped forming step of heat-treating the roller material to deform the entire inner roller material into a barrel shape whose central portion in the axial direction is expanded. Method. 3. A method of manufacturing an inner roller having an internal meshing planetary gear structure according to claim 2, wherein the burnishing step in the burnishing step includes the step of removing an outer periphery of the cylindrical inner roller material. The heat treatment in the chucking procedure is performed in a state where the chucking is released so that a predetermined pressing force to the radially circumferential side is generated at the axial center position, and the heat treatment in the barrel forming procedure is performed in a state where the chucking is released. A method for manufacturing an inner roller having an internal meshing planetary gear structure. 4. A first shaft, an eccentric body which is rotated by rotation of the first shaft, an external gear which is incorporated eccentrically rotatable with respect to the first shaft via the eccentric body, 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,
A cylindrical outer roller used for forming the internal teeth of the internal gear, of an internal meshing planetary gear structure comprising: a vertical section of an inner peripheral wall and an outer peripheral wall of the cylinder; An outer roller having an internally meshing planetary gear structure, wherein the inner and outer diameters of the wall at the axial center are larger than the inner and outer diameters of both ends. 5. A first shaft, an eccentric body which is rotated by rotation of the first shaft, an external gear which is eccentrically rotatable with respect to the first shaft via the eccentric body, 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,
In the method for manufacturing a cylindrical outer roller used to form the internal teeth of the internal gear, the internal meshing planetary gear structure provided with: Forming a cylindrical outer roller material, burnishing at least the inner peripheral wall of the inner and outer peripheral walls of the cylindrical outer roller material, and heat-treating the burnished outer roller material. And a barrel-forming step of deforming the entire outer roller material into a barrel shape whose central portion in the axial direction is bulged. 6. A method for manufacturing an outer roller having an inscribed planetary gear structure according to claim 5, wherein the burnishing step in the burnishing step comprises: removing an outer periphery of the cylindrical inner roller material. The heat treatment in the chucking procedure is performed in a state where the chucking is released so that a predetermined pressing force to the radially circumferential side is generated at the axial center position, and the heat treatment in the barrel forming procedure is performed in a state where the chucking is released. A method for producing an outer roller having an internal meshing planetary gear structure.