JP2008032054A - Rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing having an accurately machined raceway. <P>SOLUTION: This deep groove ball bearing comprises an inner ring 1 having a raceway surface 1a on the outer peripheral surface, an outer ring 2 having, on the inner surface, a raceway surface 2a opposed to the raceway surface 1a of the inner ring 1, balls 3 rollingly disposed between both the raceway surfaces 1a, 2a, a cage 4 holding the balls 3 between the inner ring 1 and the outer ring 2, and seals 5, 5 covering the opening of the gap between the inner ring 1 and the outer ring 2. At least one of the inner ring 1 and the outer ring 2 is manufactured by lathing a heat-treated round bar material. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rolling bearing.

As a manufacturing method of an inner ring and an outer ring of a rolling bearing, for example, there is a method disclosed in Patent Document 1. That is, the inner ring and the outer ring are manufactured by turning the material and then performing heat treatment. In this method, the raceway surface, inner diameter surface, outer diameter surface, and both side surfaces are all finished by turning and are not ground.
Moreover, according to the method disclosed in Patent Document 2, after turning the titanium alloy into a predetermined shape, solution treatment and aging treatment are performed to produce an inner ring and an outer ring.
JP-A-8-210359 JP 2003-148487 A

However, in the manufacturing methods disclosed in Patent Documents 1 and 2, since heat treatment is performed on the material that has been turned into a ring shape, deformation due to heat treatment occurs, and the influence remains even after finishing and is deformed. was there.
Also, since the ring-shaped material is fixed to the lathe and the inner diameter surface, outer diameter surface, etc. are processed, when processing the inner diameter surface, when gripping the outer diameter surface of the material with a chuck and processing the outer diameter surface The inner diameter surface of the material is gripped by the chuck (that is, the grip is changed during turning). Therefore, because the chuck reference differs depending on which surface is processed, the parallelism between both side surfaces and the raceway surface, the concentricity between the outer diameter surface of the outer ring and the raceway surface, and the coaxiality between the inner diameter surface of the inner ring and the raceway surface The degree may be insufficient.
Then, this invention makes it a subject to solve the problem which the above prior arts have, and to provide a rolling bearing provided with the bearing ring processed with high precision.

In order to solve the above problems, the present invention has the following configuration. That is, the rolling bearing according to claim 1 according to the present invention is a rolling bearing comprising an inner ring, an outer ring, and a plurality of rolling elements that are freely rollable between the inner ring and the outer ring. At least one of the outer rings is manufactured by turning a heat-treated round bar material.
A rolling bearing according to a second aspect of the present invention is the rolling bearing according to the first aspect, wherein the material is not re-grown in the turning process.
Furthermore, the rolling bearing according to claim 3 according to the present invention is the rolling bearing according to claim 1 or 2, wherein the round bar material is made of titanium, difficult-to-cut material, or bearing steel. To do.

  Since the rolling bearing of the present invention includes a race ring processed with high accuracy, the rotational accuracy and dimensional accuracy are excellent.

Embodiments of a rolling bearing according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial longitudinal sectional view showing a configuration of a deep groove ball bearing which is an embodiment of a rolling bearing according to the present invention.
The deep groove ball bearing of FIG. 1 includes an inner ring 1 having a raceway surface 1a on an outer peripheral surface, an outer ring 2 having a raceway surface 2a facing the raceway surface 1a of the inner ring 1 on an inner peripheral surface, and both raceway surfaces 1a and 2a. Seals 5, 5 covering a plurality of balls 3 arranged so as to be freely rollable, a cage 4 that holds the plurality of balls 3 between the inner ring 1 and the outer ring 2, and an opening of a gap between the inner ring 1 and the outer ring 2. And. The cage 4 and the seal 5 may not be provided.

  At least one of the inner ring 1 and the outer ring 2 is manufactured by turning a heat-treated round bar material. Here, the manufacturing method will be described in detail with reference to FIGS. As the round bar material, a material composed of titanium, difficult-to-cut material, or bearing steel is suitable, but a method for manufacturing an outer ring from a round bar material made of titanium will be described as an example. Titanium rolling bearings are preferably used in special environments such as transporting a semiconductor wafer cleaning apparatus.

A titanium round bar material is subjected to a solution treatment and an aging treatment, and the hardness is set to Hv 470 or more. A round bar material subjected to such heat treatment is fixed to a lathe with a chuck, and turned to produce an outer ring. The subsequent steps are the same as those in a normal rolling bearing manufacturing method.
The detailed contents of the turning process will be described with reference to FIG. First, a hole is provided on the end face on the other end side of the round bar material, one end of which is fixed with a chuck, using a cutting tool such as a drill (drilling step). Next, finishing processing is performed on the outer diameter surface and the side surface of the outer ring (outer diameter surface finishing step). Further, a raceway groove is formed in a portion corresponding to the inner diameter surface of the outer ring and finish processing is performed (groove processing step). And an outer ring | wheel is obtained by cut | disconnecting the part in which the raceway groove was formed and the finishing process was given (parting-off process).

  According to the manufacturing method as described above, all the processes such as the formation of the raceway grooves and the finishing process of the raceway surface, the inner diameter surface, the outer diameter surface, and the both side surfaces can be performed only by turning, and the grinding process etc. Other processing is not necessary. Therefore, a rolling bearing can be manufactured easily and inexpensively. In addition, since it is not necessary to perform heat treatment after turning, a rolling bearing having a raceway processed with high accuracy without deformation can be manufactured. Such a rolling bearing has excellent rotational accuracy and dimensional accuracy.

  In addition, it is not necessary to re-hold the material depending on the part to be processed, and once it is gripped with the chuck, all the processing can be performed (that is, in the above-described prior art, it was necessary to re-hold the outer ring during turning). In this embodiment, since the outer ring can be cut out from the round bar material without re-holding the material), the machining accuracy is determined by the rotation accuracy of the main spindle of the lathe. Therefore, the parallelism between both side surfaces and the raceway surface, the coaxiality between the outer diameter surface of the outer ring and the raceway surface, and the coaxiality between the inner diameter surface of the inner ring and the raceway surface are excellent, and the accuracy according to the grinding-finished rolling bearing Is obtained.

  In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment. For example, in the present embodiment, the manufacturing method has been described by taking the outer ring as an example, but the inner ring can also be manufactured by the same manufacturing method. Also, in order to suppress the wear of the cutting tool, it is important to set the allowance for the outer diameter surface to the minimum necessary. The diameter of the round bar material is 0.2 mm than the outer diameter of the raceway to be manufactured. It is preferable to make it large. Furthermore, in the case of titanium, the hardness after heat treatment is Hv 470 or more, and therefore, as a cutting tool, a tool for difficult-to-cut materials obtained by applying a multilayer coating of titanium alumina to carbide K type is suitable.

  Further, in the present embodiment, the deep groove ball bearing has been described as an example, but the rolling bearing of the present invention can be applied to various types of rolling bearings. For example, radial ball bearings, cylindrical roller bearings, tapered roller bearings, needle roller bearings, spherical roller bearings such as self-aligning roller bearings, and thrust-type rolling bearings such as thrust ball bearings and thrust roller bearings.

It is a fragmentary longitudinal cross-section which shows the structure of the deep groove ball bearing which is one Embodiment of the rolling bearing which concerns on this invention. It is process drawing explaining the manufacturing method of a rolling bearing. It is a figure explaining the content of turning.

Explanation of symbols

1 inner ring 1a raceway surface 2 outer ring 2a raceway surface 3 balls

Claims (3)

  In a rolling bearing comprising an inner ring, an outer ring, and a plurality of rolling elements that are freely rollable between the inner ring and the outer ring, a round bar material in which at least one of the inner ring and the outer ring is heat-treated is used. A rolling bearing characterized by being manufactured by turning.   The rolling bearing according to claim 1, wherein no gripping of the material is performed in the turning process.   The rolling bearing according to claim 1 or 2, wherein the round bar material is made of titanium, difficult-to-cut material, or bearing steel.

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