Patent ID: 7466050
Filing Date: 2008-12-16
Classification: F16C,G11B,H02K

Abstract:
1. A brushless motor comprising: a bracket, a shaft having a thrust support end and a loading end, the thrust support end connected to said bracket; and an oil impregnated sintered sleeve for radially supporting said shaft, said oil impregnated sintered sleeve having an inner surface larger in aperture ratio at the thrust support end and the loading end than at a central part of the oil impregnated sintered sleeve, wherein a gap between the shaft and oil impregnated sintered sleeve is for retaining a fluid, the shaft comprises a dynamic pressure generating groove on a surface facing the central part of the oil impregnated sintered sleeve, and the brushless motor further comprises a magnet connected to the shaft and a stator connected to the bracket for rotationally driving the motor.