JP3769845B2 - Processing method for bearings with dynamic pressure grooves - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In recent years, bearings used in disk rotating devices and fan motors incorporated in consumer equipment are required to have high speed and high accuracy or long life, and the need for fluid bearings with dynamic pressure grooves is increasing. The present invention relates to a processing method for processing the sleeve of the bearing with the dynamic pressure groove with low cost and high accuracy.
[0002]
[Prior art]
A method for processing a sleeve of a conventional grooved bearing will be described below with reference to FIGS. FIG. 9 is a sectional view of a sleeve of a conventional bearing with a dynamic pressure groove. Reference numeral 11 denotes a bearing having a cylindrical portion 11B. The inner peripheral surface 11C has a dynamic pressure groove 11A, and further has an escape portion 11D adjacent thereto. FIG. 10 is a configuration diagram of a bearing device incorporating a conventional bearing with a dynamic pressure groove. Reference numeral 12 denotes a shaft, and reference numeral 13 denotes a motor frame. The spherical bearing portion 13A receives the bearing 11 and presses it with a spring 14. Oil 15 is injected into the bearing gap between the bearing 11 and the shaft 12.
[0003]
The operation of the conventional method for processing a bearing with a dynamic pressure groove will be described below with reference to FIGS. Conventionally, when machining the bearing 11, as shown in FIGS. 11 and 12, the outer diameter and the inner diameter are machined with a cutting tool (not shown) using a lathe or the like, and the inner peripheral surface 11C is formed as shown in FIG. 11 (a). Cutting to dimension D1. Next, as shown in FIG. 11B, the dynamic pressure groove 11A is plastically processed on the inner peripheral surface 11C using a tool (not shown), and a burr 11E generated at this time pushes a ball (not shown) through the inner peripheral surface 11C. By processing, as shown in FIG. 11C, the diameter of the inner peripheral surface 11C was set to D2, and the processing was completed. FIG. 12 shows this processing step.
[0004]
[Problems to be solved by the invention]
However, the above configuration has the following problems. In the process of cutting the outer diameter D and the inner diameter D1 of the bearing 11 shown in FIG. 9, the material cost is high because cutting is performed from a material having a diameter larger than or equal to that of D1 in the conventional cutting process. Moreover, it took time to cut and the cost was high.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the method for processing a bearing with a dynamic pressure groove according to the present invention is to form a bearing having a cylindrical portion of a substantially cylindrical shape by forging or pressing a metal material, and cutting the inner peripheral surface of the cylindrical portion. A dynamic pressure groove is formed by plastic working on the inner peripheral surface which is finished by machining and then finished .
[0006]
By the above-described processing method, a bearing with a dynamic pressure groove can be manufactured at a low cost in a short time and with high accuracy, and wear resistance is also good.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for processing a bearing with a dynamic pressure groove according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a bearing with a dynamic pressure groove according to a first embodiment of the present invention. An inner peripheral surface 1B of the cylindrical portion 1D has a dynamic pressure groove 1A, and further has a relief portion 1C. In FIG. 2, the bearing 1 is received by the spherical receiving portion 3 </ b> A of the motor frame 3 and is pressed and fixed by the spring 4. Lubricant 5 is injected between the shaft 2 and the inner peripheral surface of the bearing 1, and when the shaft 2 rotates, the bearing rotates in a non-contact manner due to the pumping effect of the dynamic pressure groove 1A.
[0008]
A method for processing a bearing with a dynamic pressure groove in the first embodiment of the present invention will be described below with reference to FIGS. In FIG. 3, a plate material such as iron, copper, or aluminum (not shown) is processed by the concave die 6C to form the spherical surface portion 1F of the bearing 1, and the approximate shape of the inner peripheral surface 1B is drawn by the punch 6A. The punch 6A may be a general punching die or a punch having a steel part 6B and the iron part 6B cutting the inner peripheral surface 1B. In FIG. 4, at least one of the bearing 1 which is a workpiece or the cutting blade 7 rotates, and the inner peripheral surface 1B of the cylindrical portion 1D is machined with high accuracy with an error of about 1 micrometer or less. At this time, the relief portion 1C is processed in the bearing 1 by the step portion 7B as necessary. In processing the dynamic pressure groove 1A on the inner peripheral surface 1B of the bearing 1 in FIG. 5, at least one of the bearing 1 or the groove processing tool 8 which is a workpiece has a feed direction (V) and a rotation direction (W ) Works. At this time, a plurality of balls 8A are attached to the grooving tool 8, and the circumscribed circle diameter of the plurality of balls 8A is set to be slightly 10 to 50 micrometers larger than the diameter of the inner peripheral surface 1B of the bearing 1. The dynamic pressure groove 1A is plastically processed and the grooved bearing 1 is completely processed. FIG. 6 shows a process chart of the present invention. In FIG. 6, the burr removal is the same as the conventional example, and if a large burr is generated at the time of groove processing in FIG. 5, a ball or the like (not shown) is pushed through the inner peripheral surface 1B as necessary to remove the burr. To do.
[0009]
As described above, according to the method for processing a bearing with a dynamic pressure groove in the first embodiment of the present invention, since the metal plate material is processed, both the plate material cost and the processing cost are low, and the inner diameter dimension is high. Can be processed with high accuracy. Furthermore, the feature of this processing method is that iron is added to the surface of the material as compared with the conventional method, and the Vickers altitude is about 50 higher. Therefore, the wear resistance as a bearing is good.
[0010]
7 and 8 are views showing a second embodiment of the present invention. Reference numeral 10 denotes a bearing having a dynamic pressure groove 10A on the inner peripheral surface 10B and a spherical surface portion 10F.
[0011]
A processing method of the bearing with a dynamic pressure groove in the second embodiment of the present invention will be described. A material 9 made of a metal such as iron, copper, or aluminum is processed into an approximate shape of the bearing 10 shown in FIG. 8 by a forging press die (not shown). Thereafter, as in the first embodiment, the inner peripheral surface 10B is processed with high accuracy with a tolerance of about 1 micrometer or less by the same method as in FIG. 4, and then the inner peripheral surface by the same method as in FIG. The dynamic pressure groove 10A is processed into 10B.
[0012]
As described above, also in the second embodiment of the present invention, since the inexpensive material 9 can be processed, it can be manufactured at low cost and the inner diameter can be processed with high accuracy. Further, the surface height is high due to the forging effect of press working, and the wear resistance of the bearing is good.
[0013]
In FIG. 8, the bearing 10 is the same in a simple pipe shape without the spherical surface portion 10F.
[0014]
As described above, according to this embodiment, a bearing with a dynamic pressure groove can be processed at low cost.
[0015]
【The invention's effect】
As described above, according to the method for processing a bearing with a dynamic pressure groove of the present invention, the material cost and the processing cost can be reduced and the processing accuracy can be increased, and the bearing surface height can be increased to improve the wear resistance. It is something that can be done.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a bearing with a dynamic pressure groove in the first embodiment of the present invention. FIG. 2 is a configuration diagram of a bearing device using the bearing shown in FIG. Sectional view of bearing [FIG. 4] Sectional view of bearing with dynamic pressure groove after inner diameter reamer processing [FIG. 5] Sectional view of bearing during dynamic pressure groove processing [FIG. 6] Dynamic pressure in the first embodiment of the present invention Process diagram of grooved bearing FIG. 7 is a diagram of a material used in the second embodiment of the present invention. FIG. 8 is a cross-sectional view of a dynamic pressure grooved bearing in the second embodiment of the present invention. Cross-sectional view of a conventional bearing with a dynamic pressure groove [FIG. 10] Configuration diagram of a bearing device incorporating a conventional bearing with a dynamic pressure groove [FIG. 11] Explanatory drawing of processing steps of a conventional bearing with a dynamic pressure groove [FIG. Of machining process of bearing with dynamic pressure groove
DESCRIPTION OF SYMBOLS 1 Bearing 1A Dynamic pressure groove 1B Inner peripheral surface 1D Cylindrical part 8 Groove processing tool 8A Ball 10A Dynamic pressure groove 11 Bearing

Claims (2)

A tool having a cylindrical portion made of a plate-shaped metal material by press working , and finishing the inner peripheral surface of the cylindrical portion by cutting, and further having a ball on the inner peripheral surface after finishing. A processing method for a bearing with a dynamic pressure groove, in which the dynamic pressure generating groove is plastically processed. A bearing having a cylindrical portion of a substantially cylindrical shape is formed by cold or hot forging from a short rod-shaped or billet-shaped metal material , and the inner peripheral surface of the cylindrical portion is finished by cutting and further finished. A processing method for a bearing with a dynamic pressure groove, in which a dynamic pressure generating groove is plastically processed by a tool having a ball on an inner peripheral surface.

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