JP2001248646A - Machining method for grooved sleeve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machining method removing burr generated after a groove of a grooved sleeve is machined. SOLUTION: A shaft hole is provided in a bearing sleeve first, secondly a dynamic pressure generation groove is formed on an inner peripheral face of the shaft hole provided by shaft hole machining, thirdly burr generated after the groove is machined is removed by honing finish, and fourthly an inner peripheral face of the shaft hole is finished by machining such as ball vanishing. Consequently, the sleeve of a bearing with dynamic pressure groove having a uniform groove shape, satisfactory inside diameter precision and roughness, and stable performance and enabling inside diameter finish with higher precision is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for machining a bearing sleeve with a dynamic pressure groove for finishing the inner diameter of a shaft hole with a dynamic pressure groove used in a dynamic pressure type radial fluid bearing or the like with high precision.

[0002]

2. Description of the Related Art A conventional method for machining a bearing sleeve with a dynamic pressure groove will be described below with reference to FIGS. FIG. 7 is a longitudinal sectional view of a sleeve of a conventional bearing with a dynamic pressure groove.
FIG. 9 is a partially enlarged sectional view showing details of the dynamic pressure groove shown in FIG. 7, and FIG. 7 and 8
, A dynamic pressure generating groove 22 is formed in an inner peripheral surface 23 of a shaft hole 32 of the bearing sleeve 21. By inserting the shaft 24 into the shaft hole 32, the shaft 24 is inserted into the bearing sleeve 21.
Can be configured to be rotatably supported with dynamic pressure.

[0003] The conventional processing steps for the sleeve of the conventional bearing with a dynamic pressure groove described above will be described below. As shown in FIG. 9, a shaft hole 32 is provided in the bearing sleeve 21 by cutting in a process. In the next step, the dynamic pressure generating groove 22 is formed on the shaft hole inner peripheral surface 23 of the shaft hole 32 obtained by the hole processing. In order to form the dynamic pressure generating groove 22, groove processing is performed by cutting or plastic processing using a reamer. Finally, in the process, ball varnish, pin varnish or roller varnish is performed to finish the inner peripheral surface 23 of the shaft hole.

[0004]

The above-mentioned conventional processing method has the following problems. That is: When the grooves are formed by plastic working in the above process, burrs 25 as shown in FIG. 8 are formed at both ends of the grooves. Therefore, in the conventional method, the inner peripheral surface 23 of the shaft hole is finished by performing finishing such as ball varnish, pin varnish, or roller varnish in the above process. However, when the burrs 25 are large or large, residual projections are formed even after the burnishing, so that the finished surface becomes rough, and as a result, the performance of the bearing may not be sufficient.

Accordingly, an object of the present invention is to provide a bearing sleeve 21
It is an object of the present invention to provide a method of processing a sleeve with a dynamic pressure groove which enables complete removal of the burr 25 generated after the groove processing.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a method for machining a sleeve of a bearing with a dynamic pressure groove according to the present invention comprises:
After drilling the shaft hole in the bearing sleeve, a dynamic pressure generating groove is formed on the inner peripheral surface of the drilled shaft hole,
It is characterized by removing burrs after forming a dynamic pressure generating groove by honing. According to the above-mentioned method, a bearing sleeve with a dynamic pressure groove having a uniform groove shape, good inner diameter accuracy, and stable performance can be obtained.

In the invention according to another aspect, a groove is formed on an inner peripheral surface of a shaft hole of a bearing sleeve with a dynamic pressure groove, a burr after the groove processing is removed by honing, and a burnishing process is further performed to reduce an inner peripheral surface of the shaft hole. Finish. By performing this method, it is possible to obtain a bearing sleeve with a dynamic pressure groove having a uniform groove shape, good internal diameter accuracy and a good condition of the inner surface of the shaft hole, and stable performance.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the preferred embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a bearing sleeve of a bearing with a dynamic pressure groove according to an embodiment of the present invention, and FIGS. 2 to 6 are views showing processing states in respective processing steps. 2 to 5, a shaft hole 32 having a dynamic pressure generation groove 2 is formed in the bearing sleeve 1 by a known method such as boring or turning, and further by a known plastic working method or the like. After processing the dynamic pressure generating groove 2, burrs are removed by using a honing finish processing method. By inserting the shaft 4 into the shaft hole of the sleeve 1 as shown in FIG. 1, a combination of a bearing with a dynamic pressure groove and a shaft can be constituted.

2 to 5 show a processing method according to the present invention. As shown in FIG. 3, the inner peripheral surface 2 of the bearing 32 of the bearing sleeve
3, a groove is formed by a plastic working method using a rolling tool or the like, and then, as shown in FIG. 4, a processing method of removing burrs after the groove is formed by a honing tool is adopted. By using this processing method, the groove shape becomes uniform, the inner diameter accuracy is improved, and the performance is stabilized.

Next, the specific steps of this embodiment will be described with reference to FIGS. In FIG. 1, a shaft hole 32 having a dynamic pressure generating groove 2 is formed in a bearing sleeve 1. By inserting a shaft 4 into the shaft hole 32, a rotatable bearing with a dynamic pressure groove can be formed.

The processing steps of the above bearing sleeve 1 with a dynamic pressure groove will be described below. First, the bearing sleeve 1 is drilled to form the shaft hole 32 by cutting using a known lathe or the like. Next, the dynamic pressure generating groove 2 is formed in the inner peripheral surface of the shaft hole 32 in which the hole is formed. As a preferred working example, cutting or plastic working is performed by giving the groove rolling tool 6 shown in FIG. 3 the axial movement of the shaft hole 32 and the rotation around the axis. Then, as shown in FIG.
The burrs after the groove processing are removed. In the honing, it is preferable to use the rigid honing method in order to obtain high accuracy. That is, the bearing sleeve 1 is fixed to a support device of a honing machine, and a grindstone serving as a honing tool 5 is one that is spring-supported on a vertically rotating shaft 6 'of the honing machine. Finally, as shown in FIG. 5, the inner peripheral surface 3 of the shaft hole is finished by pushing the vanish ball 9 with the pressing pin 8 as necessary. As a result, it is possible to finish the inner surface, which enables a finish with higher precision. In the embodiment of FIG. 5, the method using ball varnish is shown, but the inner peripheral surface 3 of the shaft hole may be finished using pin varnish or roller varnish.

By adopting the above processing method, it is possible to obtain a sleeve of a dynamic pressure groove bearing having a uniform groove shape, a good inner diameter accuracy and a stable performance.

[0013]

As described above, by employing the method of processing a bearing sleeve with a dynamic pressure groove according to the present invention, the groove shape is uniform, the inner diameter accuracy and the roughness are better, and a more accurate inner diameter finish is possible. And a bearing sleeve with dynamic pressure grooves having stable performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a bearing sleeve machined using a method for machining a bearing sleeve with a dynamic pressure groove according to an embodiment of the present invention.

FIG. 2 is a detailed sectional view showing a part of the dynamic pressure groove of the bearing sleeve shown in FIG. 1 in an enlarged manner.

FIG. 3 is a vertical cross-sectional view illustrating a step of forming a groove in an inner peripheral surface of a shaft hole.

FIG. 4 is a longitudinal sectional view for explaining a honing finish processing step performed after the groove processing step shown in FIG. 3;

FIG. 5 is a longitudinal sectional view showing details of a ball burnishing process after the honing finishing process shown in FIG. 4;

FIG. 6 is a flowchart of a processing step of a bearing sleeve with a dynamic pressure groove according to an embodiment of the present invention.

FIG. 7 is a longitudinal sectional view of a bearing sleeve machined using a conventional method for machining a bearing sleeve with a dynamic pressure groove.

8 is an enlarged sectional view showing details of a dynamic pressure groove of the conventional bearing sleeve shown in FIG. 7;

FIG. 9 is a flowchart of a processing step of a conventional bearing sleeve with a dynamic pressure groove.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bearing sleeve 2 Dynamic pressure generating groove 3 Inner peripheral surface of shaft hole 5 Honing finish 9 Vanish ball 32 Shaft hole

Claims (2)

[Claims] 1. A step of drilling an inner peripheral surface of a shaft hole in a bearing sleeve, a step of forming a dynamic pressure generating groove in the inner peripheral surface of the drilled shaft hole, and after forming the dynamic pressure generating groove by honing. A method of processing a bearing sleeve with a dynamic pressure groove, comprising a step of removing a burr and finishing an inner peripheral surface of a shaft hole. 2. The method according to claim 1, further comprising performing a burnishing process after the deburring step.