MOTOR WITH BEARING HOLDER AND MANUFACTURE OF BEARING HOLDER

Japanese Patent JP3266500

B2

PROBLEM TO BE SOLVED: To eliminate a lathe process and realize the cost reduction by a method wherein the linear expansion coefficient in an axial direction of a ring holder which is made of thermoplastic resin containing glass fiber with a content larger than a specific value by injection molding is specified.
SOLUTION: Thermoplastic resin containing more than 15wt.% of glass fiber is injected through a film gate 11 and flows in a horizontal direction in the parts of cavities 16c and 17b which are to be protruding parts and partially turns the flow direction in a vertical direction upward and downward in the parts of cavities 16b and 17a which are to be cylindrical parts. The remaining thermoplastic resin flows further forward in a horizontal direction and reaches cavities 16a. After filling the cavities 16 and 17, the thermoplastic resin is cured and unnecessary parts such as the film gate 11, etc., are cut off to form a bearing holder. The linear expansion coefficient of the part of the bearing holder which is extended in the axial direction, i.e., the axial direction linear expansion coefficient, is not more than 3.0×10-5/°C which is about the same as the coefficient of aluminum, so that the bearing holder can be handled like an aluminum bearing holder.

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Kimio Kitajima
Masayoshi Saichi

JP9535496A

March 18, 2002

April 17, 1996

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Sankyo Seiki Co., Ltd.

H02K5/16; H02K15/14; (IPC1-7): H02K5/16; H02K15/14

JP61221545A
JP7228883A
JP861377A
JP1225523A
JP340855U

Yoshiyuki Ishibashi

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