JPH04331851A - Manufacture of trochoid group gear shape internal fitting type planetary gear reduction gear - Google Patents

Abstract

PURPOSE:To eliminate the generation of strain on a material after heat treatment and obviate the need of the posterior process such as grinding, by making an eternal gear from carbon steel, forming an inner roller hole and external gear, and heating the material in the nitrogen gas environment at a specific temperature. CONSTITUTION:As for a trochoid group tooth shape internal fitting type planetary gear reduction gear, each eccentric body 31, 32 having two eccentric surfaces whose center is eccentric for an input shaft 1 is arranged on the outer periphery of the input shaft 1. External gears 51 and 52 are arranged through a plurality of roller bearings 41 and 42 on the outer peripheral edges of the eccentric bodies 31 and 32. Further, an inner pin 7 which penetrates through a plurality of inner roller holes 6 is formed on each external gear 51, 52, and an outer pin 11 meshed with an external gear 9 is formed on the outer peripheral edge. With this constitution, the material of the external gear 51, 52 is made of carbon steel. After the inner roller holler 6 and external gear 9 are formed, the material is heated in the nitrogen gas environment and at the temperature below the A1 transformation point of the steel.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a trochoidal tooth type internal planetary gear reducer.

0002

2 is a longitudinal cross-sectional view of a conventional planetary gear reducer, and FIG. 3 is a cross-sectional view of a conventional planetary gear reducer. In the figure, 1 is an input shaft, 2 is an output shaft, 31 and 32 are eccentric bodies having shafts eccentric to the axes of the input shaft 1 and output shaft 2, 41 and 42 are roller bearings, and 51 and 52 are external A gear, 6 is an inner roller hole, 7 is an inner pin disposed through the inner roller hole 6, 8 is an inner roller disposed around the outer periphery of the inner pin 7, 9 is an external tooth, 10 is a gear. An internal gear; 11 is an external pin disposed between the external teeth 9 and the internal teeth; 12 is an output shaft flange integrally formed with the output shaft 2; 13 is the input shaft 1;
and the spline 14 formed between the eccentric bodies 31 and 32.
1,142 is a thrust bearing.

[0003] The eccentric bodies 31, 32 have two eccentric grooves, which are shifted in phase by 180°, formed around the circumference, and the roller bearings 41, 42 are disposed in the eccentric grooves. Further, the eccentric bodies 31 and 32 are hollow, and the spline 13 is formed on the inner periphery thereof. O1 and O2 in the diagram
indicates the center of rotation of the eccentric bodies 31, 32. Further, the input shaft 1 is meshed with a motor shaft or the like using another tooth portion at the other end (not shown), while rotation is transmitted to the output shaft 2 via the inner pin 7, for example. It is connected to the gear shaft on the driven side.

A large number of axial gears are formed inside the internal gear 10, and an external pin 11 is rotatably fitted into the gears. The external gears 51 and 52 are the internal pins 7
The number of inner roller holes 6 corresponds to the number of inner roller holes 6, and the inner surface of the inner roller holes 6 and the outer surface of the inner roller 8 slide. The outer shape of the external gears 51 and 52 is, for example, a closed cycloid curve, and cooperates with the external pin 11.

In the planetary gear reducer having the above configuration, when rotation is transmitted from the input shaft 1, the eccentric bodies 31 and 32 rotate via the spline 13. This rotation is further transmitted to the external gears 51 and 52 via the roller bearings 41 and 42.
transmitted to. At this time, the external teeth 9 on the outer periphery of the external gears 51 and 52 are fitted with the external pin 11. As a result, the eccentric rotation of the eccentric bodies 31 and 32 is transmitted to the inner pin 7 while changing the sliding position between the inner surface of the inner roller hole 6 and the outer surface of the inner roller 8, and the decelerated rotation is transmitted from the output shaft 2. can be taken out.

In order to prevent machining errors in each component of the planetary gear reducer from adversely affecting the rotational characteristics, rotation is transmitted from the input shaft 1 to the eccentric bodies 31 and 32 via a spline 13. together with the eccentric bodies 31, 32
and roller bearings 41, 42 and thrust bearings 141, 1
42, and the eccentric bodies 31, 32 and roller bearings 41, 42 are floated.

The external gears 51 and 52 have a hole 21 in the center, and the roller bearing 4 is inserted through the hole 21.
1,42 is slidably supported. Further, the number of inner roller holes 6 corresponding to the number of inner pins 7 is provided, and the inner roller holes 6
The inner surface of the inner roller 8 slides on the outer surface of the inner roller 8. External teeth 9 are provided on the outer peripheries of the external gears 51 and 52.
is formed and meshes with the outer pin 11.

[0008] As described above, the external gears 51 and 52 have complicated shapes and slide with other members on each surface, so
Easy to wear out. If the shape and dimensions change due to wear, deceleration cannot be performed accurately and the number of revolutions will differ from the expected one. Therefore, the external gear 51,
In No. 52, each sliding surface is first processed and then heat treated to improve durability.

That is, the material of the external gears 51, 52 made of SUJ2 or SUJ3 is first cut or forged along its outer shape, and then the cut or forged surface is machined. After that, after drilling, the roller bearing 41
, 42 and the inner roller hole 6 that forms a sliding surface with the inner roller 8 are cut. Subsequently, external teeth 9 are formed on the outer periphery of the material by hobbing, and the entire material is hardened.

Finally, the end faces, the holes 6, 21, and the external teeth 9 are sequentially ground to complete the external gears 51, 52.

[0011]

[Problems to be Solved by the Invention] However, in the above-mentioned conventional method for manufacturing a planetary gear reducer, the external gear 5
1 and 52, the material is heat-treated by quenching, which tends to cause distortion, and a grinding process for the end face, each hole 6, 21, and the external tooth 9 is required to remove the distortion, which increases manufacturing costs. It gets expensive.

The present invention solves the problems of the conventional manufacturing method of a planetary gear reducer and uses a trochoidal tooth profile that does not require post-processes such as grinding after the heat treatment process when manufacturing external gears. The object of the present invention is to provide a method for manufacturing a contact type planetary gear reducer.

[0013]

[Means for Solving the Problems] To this end, the present invention provides
An eccentric body having two eccentric surfaces whose center is eccentric with respect to the input shaft is arranged around the outer periphery of the input shaft, and the outer tooth A trochoidal tooth-shaped internal planetary gear reducer, which is equipped with a gear and includes an inner pin that passes through a plurality of inner roller holes formed in the external gear, and an outer pin that meshes with external teeth formed on the outer periphery. In the manufacturing method, the material of the external gear is carbon steel.

After processing the material to form the hole forming the sliding surface for the roller bearing, the inner roller hole, and the outer tooth, it is heated in a nitriding gas atmosphere at a temperature below the A1 transformation point of the steel. It is designed to heat up.

[0015]

[Operation] According to the present invention, an eccentric body having two eccentric surfaces whose center is eccentric with respect to the input shaft is disposed on the outer periphery of the input shaft as described above, and the eccentric body has two eccentric surfaces on the outer periphery of the input shaft. An external gear is disposed via a plurality of roller bearings, and an inner pin passes through a plurality of inner roller holes formed in the external gear, and an outer pin meshes with external teeth formed on the outer periphery. In a method for manufacturing a trochoidal tooth-shaped internal planetary gear reducer consisting of pins,
The material of the external gear is carbon steel.

After processing the material to form the hole forming the sliding surface with the roller bearing, the inner roller hole, and the outer tooth, it is heated in a nitriding gas atmosphere at a temperature below the A1 transformation point of the steel. It is designed to heat up. Since no distortion occurs in the material after heat treatment, there is no need to perform other steps after the heat treatment step.

[0017]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a process diagram of a method for manufacturing a planetary gear reducer showing an embodiment of the present invention. In the figure,
31 is a step of cutting or forging the material. The step 31
In this case, the material made of S45C or other carbon steel is
The external gears 51 and 52 (see FIG. 2) are cut or forged along the outer shape. At this point, the holes 21 (see Figure 2), inner roller holes 6 (see Figure 2) and outer teeth 9 (see Figure 2)
is not formed.

Step 32 is a step of grinding the die formed by the cutting and forging steps described above to form the outer shape of the external gears 51 and 52. Further, 33 is a hole machining process after forming the outer shape of the external gears 51, 52. roller bearing 41,
42 and the hole 21 forming a sliding surface with the inner roller 8.
Drilling is performed to form an inner roller hole 6 that forms a sliding surface with the inner roller.

Reference numeral 34 indicates a hole grinding process after the drilling process, and the hole 21 and the inner roller hole 6 are formed by the hole grinding process 34. In addition, 35 is an external gear 51, 52.
This is hobbing to form external teeth 9 on the outer periphery of the . 3
6 is a heat treatment step for improving the durability of the external gears 51, 52 after the holes 21, inner roller holes 6, and external teeth 9 have been formed.

In this heat treatment step, S45C is heated in a nitriding atmosphere at a temperature below the A1 transformation point of steel, and then gradually cooled in the same atmosphere to a slightly lower temperature. After being held in that state for a while, it is rapidly cooled and further tempered. The hardened layer formed by such treatment becomes Fe-N martensite, and the hardened layer forms a 700Hv
The above hardness can be obtained, and wear resistance and surface pressure hardness can be improved. However, there is no effect of nitrogen penetration and the internal structure does not undergo transformation, so no deformation occurs.

[0021] In addition, inexpensive carbon steel can be used as the material, and the heat treatment time is shortened.

[0022]

As described above in detail, according to the present invention, an eccentric body having two eccentric surfaces whose center is eccentric with respect to the input shaft is disposed around the outer periphery of the input shaft, An external gear is disposed via a plurality of roller bearings disposed on the outer circumferential edge of the eccentric body, and an inner pin passing through a plurality of inner roller holes formed in the external gear, and an inner pin formed on the outer circumferential edge. In the method for manufacturing a trochoidal tooth-shaped internal planetary gear reducer comprising an external pin meshing with external teeth, the material of the external gear is carbon steel.

After processing the material to form the hole forming the sliding surface with the roller bearing, the inner roller hole, and the outer tooth, it is heated in a nitriding gas atmosphere at a temperature below the A1 transformation point of the steel. It is designed to heat up. Since no distortion occurs in the material after heat treatment, there is no need to perform other processes such as grinding after the heat treatment process, and since carbon steel is used as the material, costs can be reduced.

[Brief explanation of drawings]

FIG. 1 is a process diagram of a method for manufacturing a planetary gear reducer showing an embodiment of the present invention.

FIG. 2 is a longitudinal cross-sectional view of a conventional planetary gear reducer.

FIG. 3 is a cross-sectional view of a conventional planetary gear reducer.

[Explanation of symbols]

1 Input shaft 31, 32 Eccentric body 41, 42 Roller bearing 51, 52 External gear 6 Inner roller hole 7 Inner pin 9 External teeth 11 Outer pin 21 Hole

Claims (1)

[Claims] Claim 1: An eccentric body having two eccentric surfaces whose center is eccentric with respect to the input shaft is disposed on the outer circumference of the input shaft, and a plurality of roller bearings are disposed on the outer circumference of the eccentric body. A trochoidal tooth profile inscribed system consisting of an internal pin that passes through a plurality of internal roller holes formed in the external gear, and an external pin that meshes with external teeth formed on the outer periphery. In the method for manufacturing a planetary gear reducer, (a) the material of the external gear is carbon steel, and (b) a hole forming a sliding surface with the roller bearing, the inner roller hole, and the outer tooth are formed. After that,
(c) A method for manufacturing a trochoidal tooth profile internal planetary gear reducer, which comprises heating in a nitriding gas atmosphere at a temperature below the A1 transformation point of steel.