Dynamic pressure bearing device and method of manufacturing the same
AssigneeKabushiki Kaisha Sankyo Seiki Seisakusho
InventorsMasayuki Ishikawa, Hiromasa Marumo, Hiroshi Zenisawa
Life of this patent
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Abstract
In order to manufacture a dynamic pressure bearing device, there are provided a shaft member, and a thrust plate formed with a press-fitting portion into which the shaft member is press-fitted. At least two relief portions are formed in at least one of the press-fitting portion of the thrust plate and a part of the shaft member which corresponds to the press-fitting portion. The shaft member is press-fitted with the press-fitting portion such that the thrust plate extends perpendicular to an axial direction of the shaft member, while making the relief portions absorb press-fitting stress.
Claims8
A dynamic pressure bearing device, comprising:
- a shaft member;
- a thrust plate, formed with a press-fitting portion into which the shaft member is press-fitted such that the thrust plate extends perpendicular to an axial direction of the shaft member;
- a bearing member, being opposed to the thrust plate for forming a thrust dynamic pressure bearing portion;
- and
- at least two relief portions, for absorbing press-fitting stress directed to the shaft member, the relief portions provided in the press-fitting portion of the thrust plate;
- wherein a central portion of the thrust plate is thinned to define a space which allows deformation of the press-fitting portion in a thickness direction of the thrust plate when the press-fitting of the shaft member is performed.
A method of manufacturing a dynamic pressure bearing device, comprising the steps of:
- providing a shaft member;
- providing a thrust plate;
- thinning a center portion of the thrust plate to form press-fitting portion into which the shaft member is press-fitted;
- forming at least two relief portions in at least one of the press-fitting portion of the thrust plate and a part of the shaft member which corresponds to the press-fitting portion;
- and
- press-fitting the shaft member with the press-fitting portion such that the thrust plate extends perpendicular to an axial direction of the shaft member, while making the relief portions absorb press-fitting stress, and making a space defined by the thinning step allow deformation of the press-fitting portion in a thickness direction of the thrust plate.
Dependencies are inferred from the claim text.