Manufacturing method for sinterring dynamic pressure bearing

Abstract

A method of manufacturing sintered hydrodynamic bearing can manufacture sintered hydrodynamic bearing with reduced or blocked pore clearance generated by shrinkage accompanied with impregnated resin solidification with ensured quality and stability and few processes. The manufacturing method has the resin enclosing process with the following operations: a resin impregnating operation impregnating the anaerobic resin monomer with acrylate or methacrylate as main component into pores of a porous sintered body; a residual resin washing operation washing the residual resin adhered to the surface of the porous sintered body; a resin solidification operation keeping the porous sintered body at a temperature above resin solidification temperature after resin washing and solidifying above-mentioned anaerobic resin monomer impregnated in the pores. The manufacturing method is characterized in that above-mentioned resin enclosing process is carried out repeatedly, and the anaerobic resin monomer with 0.1-1 wt% organic peroxide is used in the resin impregnating operation of at least the last resin enclosing process.

Description

technical field [0001] The present invention relates to a sintered bearing suitable for use in a disk drive spindle motor and the like, and more particularly to a method for manufacturing a sintered dynamic pressure bearing in which pores of a porous sintered body are closed. Background technique [0002] Recently, motors for information equipment are required to have high rotation accuracy, high-speed stability, low noise, mass production performance, and low cost due to high recording density and high-speed processing of information. Bearings that support rotating shafts are also required to have this kind of performance. As a bearing structure, for example, various grooves for generating dynamic pressure are provided on the bearing surface, and while being fixed in the bearing housing, it is filled with lubricating oil. When the rotating shaft rotates, the sintered bearing supports the rotating shaft in a non-contact manner by the action of grooves for generating dynamic ...

AI Technical Summary

Problems solved by technology

[0004] The above-mentioned method of high-density molding of sintered dynamic pressure bearings has the following problems: Since the raw material powder is compressed and molded with an increased pressure, the amount of deformation accumulated in the molded body is large and the dimensional accuracy is deteriorated.

In this case, even if the size is corrected by recompression, since the raw material is high-density, it is difficult to deform, and it cannot be corrected with good accuracy.

In addition, there is a problem in the method of sealing the bearing by various sand blasting or drum treatment. With the miniaturization of the dynamic pressure bearing used in the information equipment, it is difficult to supply the medium such as sand blasting to the inside of the bearing. Otherwise, the shape of the dynamic pressure groove formed on the inner diameter surface and / or end surface of the sintered bearing may be damaged

However, in this case, the resin solidified in the pores of the sintered body deteriorates the deformability of the sintered body, and the dynamic pressure groove cannot be formed with good precision.