JPH03216221A - Manufacture of fluid bearing - Google Patents

Abstract

PURPOSE:To simplify a working and to improve a mass-productivity by pressurizing an inner peripheral surface of a hollow die having plural projections on the outer peripheral surface, expanding a pipe to the radius direction, pressing it to the inner peripheral surface of fluid bearing and transferring the prescribed rugged shape. CONSTITUTION:By applying an inner pressure P to the die 1 with the prescribed shape on its outer peripheral surface, a hollow blank material 2 of the bearing, etc., is expanded, pressed and transferred with this prescribed shape to the inner surface of this blank material. In order to apply this pressure P inside the die 1, the pressure room is constituted of a seal rod 3, a seal plate 4 and sealing materials, 5a, 5b, 5c, the reaction force of the inner pressure P and the sealing force are applied by pushing a hydraulic cylinder 6. The manufacture of the fluid bearing with the simple working, the high mass-productivity, the low cost and the high accuracy for working is realized.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method of manufacturing a bearing for a hydrodynamic bearing device.

[Conventional technology]

Traditionally, the manufacturing method for hydrodynamic bearings has been machining (Japanese Patent Application Laid-open No. 1983-
225218) or hot plastic working using the difference in thermal expansion (Japanese Unexamined Patent Publication No. 2444/1983), and etching processing (Journal of Japan Society of Mechanical Engineers Vol. 91 No. 834). can also be processed.

[Problem to be solved by the invention]

The conventional machining techniques described above have the problems of being difficult to process, having low mass productivity, and being expensive. In addition, hot plastic working using the difference in thermal expansion has the problem of low processing accuracy and high cost due to variations in thermal distribution, coefficient of thermal expansion, etc. Furthermore, the etching process can only form a rectangular groove cross-section, and there are also problems in that mass production is low and costs are high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a hydrodynamic bearing that is highly mass-producible, allows the cross-sectional shape of the groove to be changed as appropriate, is low in cost, and has high processing accuracy.

[Means to solve the problem]

In order to achieve the above object, the present invention expands the mold in the radial direction by applying pressure to the inner peripheral surface of a hollow mold having a predetermined shape on the outer peripheral surface. A mold is pressed against the fluid bearing of the workpiece, and a predetermined groove or uneven shape is transferred to the inner circumferential surface of the fluid bearing.

[Effect]

The present invention enables the groove or uneven shape to be transferred and formed on a bearing of a workpiece to be divided into an outer mold having a transfer part of the mold and an inner mold disposed inside the mold, so that the transfer part can be divided into an outer mold having a transfer part of the mold and an inner mold disposed inside the mold. Changes can be made easily by replacing only the outer mold, and bearings with grooves or irregularities of arbitrary shapes can be easily fabricated.

Furthermore, a gap sensor installed in the mold measures the distance between the bearing of the workpiece and the mold, and the depth of the predetermined shape transferred to the bearing is controlled and processed. Therefore, machining accuracy is further improved.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 to 6.

FIG. 1 shows an embodiment of the invention. An internal pressure P is applied to a mold 1 having a predetermined shape on the outer circumferential surface, and the mold 1 with an enlarged diameter is pressed against a hollow material 2 such as a bearing to form a predetermined shape on the inner peripheral surface of the hollow material 2 such as a bearing. Transfer processing. At this time, in order to apply pressure P to the inner circumferential surface of the mold 1, a pressure chamber is formed by the seal rod 3, seal plate 4, and seal materials 5a, 5b, and 5c, and the hydraulic cylinder 6 is pushed out to react to the internal pressure P. Adds power and sealer. Note that the pressure generator is not shown here.

FIG. 2 shows a second embodiment of the present invention, in which the internal pressure P
By adding multiple protrusions to the outer circumferential surface, the mold is enlarged.
This shows a process in which a mold is pressed onto a hollow material 2 such as a bearing to transfer a predetermined shape. In particular, when the mold is divided into an inner mold 1a and an outer mold 1b, and the shape to be transferred to the hollow material 2 such as a bearing is changed, it is only necessary to change the outer mold 1b, and the mold Easy to replace. In addition, the pressure P
The method of adding and sealing is the same as the embodiment shown in FIG.

FIG. 3 shows a third embodiment of the invention. This example shows a method of enlarging a mold having a predetermined shape on the outer periphery and transferring the predetermined shape onto the inner peripheral surface of a hollow material 2 such as a bearing, as shown in FIGS. 1 and 2. ing. In particular, inner mold IC
A similar taper is provided on the taper rod 7, and the hydraulic cylinder 6 is pushed out to enlarge the molds 1b and lc. In this case, since no pressure medium is used, there is no risk of seal leakage.

FIG. 4 shows an embodiment of the present invention. In this example, the internal pressure P
This figure shows a method of enlarging a mold having a plurality of protrusions on the outer circumferential surface by adding the above, and transferring a predetermined shape onto the inner circumferential surface of a bearing or the like. At this time, since an integrated mold 1d is used in which the mold is integrated with the pressure chamber, the pressure medium will not leak outside, so the pressure increase time can be shortened, mass productivity is high, and the pressure medium will not leak. Clean processing is possible as there is no dirt.

FIG. 5 shows a fifth embodiment of the invention. This example is the first
As shown in the figures through FIG. 4, a method is shown in which a mold having a plurality of protrusions on the outer circumferential surface is expanded by pressure or the like to transfer a predetermined shape onto the inner circumferential surface of a hollow material such as a bearing. especially,
Using the gap sensor 8 embedded in the mold, the mold 1d
By machining while measuring the distance between the protrusion and a hollow material such as a bearing, the depth of the protrusion can be machined with high precision.

FIG. 6 shows a sixth embodiment of the invention. This example shows the process of processing a hollow material 2a into a perfect circle.

Internal pressure P is applied inside the mold le to expand the mold, and the hollow material 2a is pressed and processed into a perfect circle. The shape of the mold 1e is determined in advance so that the mold becomes a perfect circle during the rounding of the hollow material 2a. Therefore, the hollow material 2a that has been machined into a perfect circle can be used for things that require roundness, straightness, and cylindricity, such as motor cases and rotary compressor cases.

Note that although the description has been made regarding machining of a perfect circle, the present invention can also be applied to machining of other shapes such as polygons.

〔Effect of the invention〕

According to the present invention, processing is easier and easier than conventional machining, hot plastic working using thermal expansion difference, and etching.
It is possible to provide a method for manufacturing a fluid bearing that is highly mass-producible, low cost, and has high processing accuracy.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view of one embodiment of the present invention, FIG. 2 is a vertical cross-sectional view of a second embodiment of the present invention, and FIG. 3 is a vertical cross-sectional view of a third embodiment of the present invention. 4 is a vertical cross-sectional view of the fourth embodiment of the present invention, FIG. 5 is a vertical cross-sectional view of the fifth embodiment of the present invention, and FIG.
The figure is a longitudinal sectional view of a sixth embodiment of the present invention. 1...Mold, 2...Hollow material such as bearing, 3...Seal rod, 4...Seal plate, 5a, 5b, 5
c... Seal material, 6... Hydraulic cylinder, 7... Taper rod, inferior 1 Figure? 2 2 Figure 2 Figure 3 Figure ■ 4 Figure ■ 5 Figure

Claims (1)

[Claims] 1. In a method for manufacturing a hydrodynamic bearing, pressure is applied to the inner peripheral surface of a hollow mold having a plurality of protrusions on the outer peripheral surface to expand the mold in the radial direction, and the mold is inserted into the fluid bearing. A method for manufacturing a hydrodynamic bearing, characterized in that a predetermined groove or uneven shape is transferred onto the inner circumferential surface of the bearing by pressing the circumferential surface.