JPS5944527B2 - Manufacturing method of circumferentially split bearing ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a circumferentially split bearing ring.

Bearing rings for double-row thrust cylindrical roller bearings or three- or four-point contact type ball bearings that generally have flanges at both ends have an inner or outer ring divided in the circumferential direction to insert rolling elements such as rollers and balls. There is a need to.

Conventionally, bearing rings were manufactured by cutting them into pieces by lathe, then heat-treating and polishing them. However, with the manufacturing method of dividing the parts by turning and then heat-treating and polishing them, the width becomes smaller and the wall thickness becomes thinner, resulting in differences in heat treatment distortion and residual stress.
Furthermore, it is not only difficult to manufacture as it requires separate polishing processes, but also has problems with accuracy after assembly.Furthermore, since the dividing surfaces are smooth, there is a possibility of slipping on the dividing surfaces during use. Therefore, if the bearing ring is naturally split, the polishing process can be done in one step, assembly is easy, and the accuracy is also satisfactory, and there is no slipping on the split surface. Currently, this natural splitting method involves cutting deep circumferential grooves with a V-shaped cross section into the split parts of the bearing ring by turning the inner and outer diameters until the groove bottom thickness is approximately 1.2 to 2 mm. After heat treatment and polishing, a method is used in which the oil holes located on the circumferential grooves having an angular cross-section are struck, thereby allowing cracks to grow from the oil holes and splitting the oil holes. This method presents problems, especially with large bearing rings. That is, in turning, there is a high possibility that deformation will occur when the remaining wall thickness is reduced to about 2 mm, and there is also a risk of quench cracking during heat treatment. Furthermore, since the oil holes serve as starting points, the number of oil holes must be increased, otherwise there is a risk that the cracks will deviate from the circumferential grooves having an angular cross-section. Therefore, the number of modifications required for production increases. Furthermore, in the case of a bearing ring for a three-point or four-point contact type ball bearing, the dividing portion must have a certain thickness, and it has been impossible to divide the ring by natural division using the above-mentioned method. In order to improve the above disadvantages of the conventional method, the depth of the circumferential groove of the V-shaped cross section should be made shallower relative to the wall thickness of the bearing ring, the remaining wall thickness should be increased, and the number of oil holes should be reduced. It is possible to reliably break the material along a circumferential groove having a V-shaped cross section even when the material is broken, and the dividing operation is easy and does not involve any danger.

This invention has been developed in view of the above problems, and its configuration will be described below with reference to the embodiment shown in FIGS. 1 and 2.

In Fig. 1, 1 is a cylindrical bearing ring in which a shallow circumferential groove 2 with a V-shaped cross section is previously provided in the center of the outer circumference, and 3 is rotatably supported on the outer diameter side of the bearing ring 1. It is a rotating shaft, and rollers 4 and 5 are attached to two positions of the rotating shaft 3, which abut against both ends of the outer diameter of the bearing ring 1.

A rotating shaft 6 is rotatably supported on the inner diameter side of the bearing ring 1, and a roller 7 that comes into contact with the inner diameter center portion of the bearing ring 1 is attached to a part of the rotating shaft 6.

The bearing ring 1 is supported at three points by the rollers 4, 5, and 7. Incidentally, a circumferential positioning groove 8 for positioning the rotating shaft 6 is provided in the center portion of the inner diameter side of the bearing ring 1 as necessary. Then, the rotating shafts 3 and 6 are rotated, and the rotating shaft 3 is located on the outer diameter side of the bearing ring 1 from the outside in the radial direction.
is pressed against the bearing ring 1 with a load P, and a crack develops along the shallow circumferential groove 2 having a V-shaped cross section due to three-point bending fatigue due to the load P, and the bearing ring 1 is divided in the circumferential direction. According to this method, the notch depth of the shallow circumferential groove 2 with a V-shaped cross section provided in the bearing ring 1 can be shallow regardless of the product wall thickness, and the number of oil holes and the dividing surface can be reduced. The shape of the clip for joining may be arbitrary.

Incidentally, if the following process is performed before dividing by the three-point bending fatigue described above, division can be easily performed with a smaller load.

That is, after heat-treating and polishing a bearing ring 11 having a shallow circumferential groove 12 with a cross-sectional shape in the center of its outer diameter, both axial end surfaces 11a, 1 of the bearing ring 11 are formed as shown in FIG.
By repeatedly compressing the bearing ring 11 in the axial direction with a load F from 1b, a crack is generated from the bottom of the groove 12 perpendicular to the axial direction, and the bearing ring 11 with this crack is
Divided in the circumferential direction by three-point bending fatigue using the method shown in the figure. In addition, when a circumferential groove with a V-shaped cross section is provided in the center of the inner diameter of the bearing ring, a roller is pressed against two points on both ends of the inner diameter where the circumferential groove is provided and one point in the center of the outer diameter. It is divided in the circumferential direction. As explained above, the present invention provides shallow circumferential grooves with a V-shaped cross section on the outer or inner circumference of a cylindrical bearing ring for double-row thrust cylindrical roller bearings or three-point or four-point contact ball bearings. After applying heat treatment and polishing, two positions straddle the circumferential groove on the circumferential groove side and one position corresponding to the circumferential groove on the back side of the circumferential groove.
A three-point bending load is applied from the radial direction to the bearing ring, and the load position is displaced in the circumferential direction of the bearing ring.Three-point bending fatigue causes cracks to grow from the bottom of the circumferential groove with a V-shaped cross section. By allowing the bearing ring to split naturally in the circumferential direction, the remaining wall thickness at the circumferential groove position can be increased relative to the bearing ring wall thickness, preventing quench cracking during heat treatment, and by performing polishing before splitting. As a result, the number of machining machines can be reduced and efficiency can be improved, finishing accuracy can also be made uniform, and there is no need to increase the number of oil holes. A radial load is applied to two points on both sides of the groove on the circumferential groove side and one point on the back side of the circumferential groove, and the load position is displaced in the circumferential direction of the bearing ring.Through three-point bending fatigue, the cross section V Since the crack propagates from the groove bottom of the letter-shaped circumferential groove and causes the bearing ring to split naturally in the circumferential direction, not only small but also large bearing rings can be safely and reliably separated in the circumferential position. It can be divided into two parts, the dividing operation is easy, and the dividing device can be simplified.

[Brief explanation of the drawing]

FIG. 1 is a drawing showing an embodiment of the present invention, and FIG. 2 is a drawing showing a pre-stage process applied as necessary. 1, 11... Bearing ring, 2, 12...
- Circumferential groove with V-shaped cross section, 3, 6...Rotating shaft.

Claims (1)

[Claims] 1 A shallow circumferential groove with a V-shaped cross section is provided on the outer or inner periphery of a cylindrical bearing ring for double-row thrust cylindrical roller bearings or three-point or four-point contact ball bearings, and heat treatment and polishing are performed. After this, a three-point bending load is applied from the radial direction to two locations on the circumferential surface on the circumferential groove side that straddle the circumferential groove, and one location on the back surface of the circumferential groove that corresponds to the circumferential groove. , by displacing the load position in the circumferential direction of the bearing ring, and using three-point bending fatigue, cracks grow from the bottom of the circumferential groove with a V-shaped cross section, causing the bearing ring to naturally split in the circumferential direction. A manufacturing method for a circumferentially split bearing ring.