JP3321228B2 - Method of manufacturing raceway for rolling bearing - Google Patents

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 raceway ring for manufacturing an inner ring or an outer ring as a raceway ring in a sealed deep groove ball bearing or other sealed rolling bearings .

[0002]

2. Description of the Related Art Conventionally, bearing rings of rolling bearings are processed in the following steps. In other words, for a material forged into the basic shape of a raceway by cold rolling or the like, the raceway ring is completed through the steps of raw turning, heat treatment, grinding, and superfinishing. The grinding and superfinishing steps are specifically the following steps. a. For outer ring Width grinding-Outer diameter centerless grinding-Rolling surface grinding-Rolling surface super finish b. For inner ring Width grinding-rolling surface grinding-inner diameter grinding-rolling surface super finishing

[0003]

As described above, conventionally, many steps are required for grinding, and the processing cost is high. Further, in the case of a bearing with a seal, there is a problem that it is difficult to obtain high precision for the seal groove as described below.

That is, since the strained material is distorted in the heat treatment process, various kinds of deformation are required to correct the deformation, improve the roughness accuracy, improve the finished dimensional accuracy, and the like during the subsequent grinding. We are carrying out grinding. However, when a seal groove is provided in a race such as a deep groove ball bearing with a seal, the seal groove is generally not subjected to post-processing after heat treatment, and distortion due to heat treatment remains generated. Normal bearings can tolerate this degree of deformation of the seal, but for high-precision products, for example, low-torque, high-precision bearings, to stabilize rotational resistance due to contact between the seal and the race In addition, post-processing is required for the seal groove, and the number of manufacturing steps becomes extremely large. Further, post-processing of the seal groove is also required for ensuring prevention of grease leakage. Further, it may be necessary to remove the quenched scale remaining in the seal groove for noise prevention or the like.

SUMMARY OF THE INVENTION It is an object of the present invention to simplify the process of polishing the raceway surface, thereby reducing the manufacturing cost, and when providing a seal groove or the like, the rolling can be easily performed and high quality can be achieved. An object of the present invention is to provide a method for manufacturing a bearing race.

[0006]

According to a method of manufacturing a bearing ring of the present invention, a raw material having a shape substantially equal to the shape of the above-mentioned raceway is obtained by forging a material which will be a raceway of a rolling bearing. Heat treatment for surface hardening of raw material
The following were Tsu line in a heating furnace, a rolling surface and a method of turning the seal groove to a desired shape. After turning , the rolling surface is superimposed with a whetstone
To finish .

[0007]

According to this method, since the cutting is performed after the heat treatment, the heat-treated deformation of the material can be removed in the cutting process. Therefore, by performing processing with high precision at the time of cutting, the subsequent polishing process can be simplified, and for example, super finishing can be performed directly without omitting the grinding process on the rolling surface.
Further, when a seal groove is provided in the race, the seal groove can be formed simultaneously with the rolling surface in the cutting process after the heat treatment. Therefore, heat treatment deformation of the seal groove can be removed, and quenched scale and the like attached to the seal groove can also be removed. Further, since the machining is performed simultaneously, the concentricity between the rolling surface and the seal groove is maintained with high accuracy. For these reasons, grease leakage is prevented and seal resistance is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 3 shows a bearing for processing the outer ring 1 and the inner ring 2 which are the race rings by the manufacturing method of this embodiment. This bearing is a sealed deep groove ball bearing, and has inner ring 2 and outer ring 1
The rolling element 4 held by the retainer 3 is interposed between them, and seals 5 and 5 are provided on both surfaces. The seal 5 is made of a rubber material containing a mandrel. The outer race 1 is formed with a rolling surface 1a formed of an arc groove on the inner diameter surface and a seal groove 1b having an arc-shaped cross section for mounting the outer diameter portion of the seal 5 in a fitted state. Inner ring 2
A rolling surface 2a formed of an arc groove on the outer diameter surface and a flat bottom seal groove 2b for slidingly contacting the inner diameter portion of the seal 5 are formed.

FIG. 1 shows a manufacturing process of the outer race 1. First, as shown in FIG. 1A, an outer race material W1 having a substantially shape of the outer race 1 is obtained by forging such as cold rolling. After the material W1 is quenched in the heating furnace 6 to harden the surface (B), width grinding (C) and outer diameter grinding (D) are performed. Next, the material W1 having the outer diameter ground is turned to process the rolling surface 1a and the seal groove 1b into desired shapes (E). A dashed line c in the figure shows the inner diameter surface shape of the raw material W1 before turning. Since this turning is hardened steel cutting, a cutting tool capable of such cutting is used. As a cutting tool capable of cutting hardened steel, for example, a sintered tool obtained by adding a special ceramic binder to CBN (cubic boron nitride) is commercially available. Finally, the rolling surface 1a is super-finished (F) with the grindstone 7, and the material W1 is completed as the outer ring 1.

FIG. 2 shows a manufacturing process of the inner ring 2. First, as shown in FIG. 1A, an inner race material W2 having a substantially shape of the inner race 2 is obtained by forging such as cold rolling. After the material W2 is quenched in the heating furnace 6 to harden the surface (B), width grinding (C) is performed. Next, the material W2 whose width has been ground is turned, and the rolling surface 2a and the seal groove 2 are turned.
b is processed into a desired shape (D). A dashed line d in the figure shows the outer diameter surface shape of the blank W2 before turning. This turning is also hardened steel cutting. The inner ring 2 is completed by subjecting the cut material W2 to inner diameter grinding (E) and superfinishing of the rolling surface 2a with a grindstone 8.

According to this method for manufacturing a raceway, the outer race material W
1 and the inner ring material W2 are both cut after quenching, so that heat treatment deformation of the materials W1 and W2 can be removed in the cutting process. Therefore, by performing high-precision machining at the time of cutting, the subsequent rolling surface grinding step can be omitted, and the rolling surfaces 1a and 2a can be directly super-finished. For this reason, the process is simplified and the processing cost is reduced.

In the cutting process after the quenching, the rolling surface 1
In order to process the seal grooves 1b and 2b simultaneously with a and 2a,
The heat treatment deformation of the seal grooves 1b and 2b can also be removed, and high roundness can be obtained. Further, the quenched scale attached to the seal grooves 1b and 2b can be removed. Further, since the machining is performed simultaneously, the concentricity between the rolling surfaces 1a and 2a and the seal grooves 1b and 2b can be maintained with high accuracy. For these reasons, a low-torque bearing with little grease leakage and small seal contact resistance can be obtained. Further, it is possible to obtain a clean sound good product having no quenched scale adhered to the seal grooves 1b and 2b.

FIG. 4 shows another example of a deep groove ball bearing with a seal. In this example, the seal 9 is formed of a metal plate and attached to the seal groove 2 b ′ of the inner race 2, and the seal 9 is formed of a metal plate.
A labyrinth seal is formed between the labyrinth seal and b ′. Other configurations are the same as those in the example of FIG. Also in the case of this configuration, the outer ring 1 and the inner ring 2 can be manufactured by the raceway ring manufacturing method shown in conjunction with FIGS.

Although the above embodiments have been described in connection with the case where the present invention is applied to a deep groove ball bearing with a seal, the present invention is applicable to any bearing with a seal such as a tapered roller bearing or a cylindrical roller bearing.
If, cut in applied to the bearing generally shy rolling. Also, in the case of a bearing that guides the cage to the raceway (inner or outer ring), since the guide surface of the raceway is precisely machined by cutting, the sliding contact surface of the cage is worn or lubrication is poor. That can be reduced.

[0015]

According to the method for manufacturing a bearing ring of the present invention, since the cutting is performed after heat-treating the raw material, the heat-treated deformation of the material can be removed in the cutting process. Therefore, the subsequent polishing process for the rolling surface can be simplified, and the processing cost can be reduced by, for example, directly performing super finishing without the grinding process. Also, when machining the seal groove on the raceway, the seal groove can be machined simultaneously with the rolling surface in the cutting process after the heat treatment, so that the heat treatment is not deformed, the roundness is good, and the rolling surface is improved. Seal groove having a high concentricity with respect to. Therefore, a low-torque bearing with little grease leakage and small seal contact resistance can be obtained. Further, it is possible to obtain a clean sound good product having no quenched scale adhered to the seal groove and the like.

[Brief description of the drawings]

FIG. 1 is a process explanatory view of an outer ring manufacturing process in a raceway ring manufacturing method according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram of a process of an inner ring manufacturing process in the method of manufacturing a raceway ring.

FIG. 3 is a partial cross-sectional view of a bearing using the inner and outer rings manufactured by the same manufacturing method.

FIG. 4 is a partial sectional view of another bearing to which the manufacturing method can be applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer ring (track ring), 1a ... Rolling surface, 1b ... Seal groove,
2 ... inner ring (track ring), 2a ... rolling surface, 2b ... seal groove,
W1: Outer ring material, W2: Inner ring material

Claims (1)

(57) [Claims] 1. A process of obtaining, by forging, a raw material that becomes a raceway of a rolling bearing and substantially has the shape of the raceway, and hardening the surface of the raw material by heat treatment in a heating furnace. A process of turning the heat-treated material to form a rolling surface and a seal groove into a desired shape, and a process of super-finishing the rolling surface of the turned material with a grindstone. And a method of manufacturing a bearing ring for a rolling bearing.