Centerpiece structure of brush-less motor and method of manufacturing brush-less motor
AssigneeAsmo Co., Ltd.
InventorsKeisuke Sasaki, Kenji Yoshimura, Toshio Ishikawa
Life of this patent
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Abstract
A brush-less motor has a center piece, which has a flange portion fixed to a motor holder and a cylindrical portion fixed to a stator core at the outer periphery of the cylindrical portion. The cylindrical portion has a pair of bearings disposed inside the cylindrical portion to rotatably support said shaft. The center piece is formed by a pressing machine to omit a finishing machine work.
Claims7
A center piece structure of a brush-less motor including a motor holder, a rotor, a stator core having a central hole, said center piece structure comprising:
- a flange portion fixed to said motor holder;
- a cylindrical portion having outer periphery fixed to said central hole of said stator core and an inner periphery with at least a pair of integrally formed retaining surfaces;
- and
- a pair of bearings disposed inside thereof in contact with said retaining surfaces to rotatably support said rotor at a prescribed axial position;
- wherein
- said center piece is press-formed to provide said pair of retaining surfaces together with said cylindrical portion.
A center piece structure of a brush-less motor including a motor holder, a rotor having a shaft, a stator having a stator core with a center hole and a stator winding, said center piece structure comprising:
- a flange portion fixed to said motor holder;
- a cylindrical portion having outer periphery press-fitted to said center hole of said stator core and an inner periphery with at least a pair of integrally formed retaining surfaces spaced apart from each other in an axial direction;
- and
- a pair of bearings disposed inside thereof in contact with said retaining surfaces to rotatably support said rotor at a prescribed axial position, wherein
- each of said pair of bearings has a bearing portion supporting said rotor shaft and an extending portion having an outer periphery press-fitted into said inner periphery of said cylindrical portion,
- said bearing portion has an outside diameter smaller than said outer periphery of said extending portion, and
- said extending portion has an inside diameter larger than said bearing portion.
A center piece structure of a brush-less motor including a motor holder, a rotor having a shaft, a stator having a stator core with a center hole and a stator winding, said center piece structure comprising:
- a flange portion fixed to said motor holder;
- a cylindrical portion having outer periphery press-fitted to said center hole of said stator core and an inner periphery with at least a pair of integrally formed retaining surfaces spaced apart from each othe in an axial direction;
- and
- a pair of bearings disposed inside thereof in contact with said retaining surfaces to rotatably support said rotor at a prescribed axial position, wherein
- said cylindrical portion has at least a pair of cutdown projections extending radially inward to form said retaining surfaces.
Dependencies are inferred from the claim text.