Patent ID: 7073946
Filing Date: 2006-07-11
Classification: F16C,G11B,H02K

Abstract:
1. A bearing unit comprising: a shaft; a radial bearing to support the shaft circumferentially; a thrust bearing to support the shaft at one of the thrusting-directional ends thereof; and a housing in which the radial and thrust bearings supporting the shaft are disposed and a viscous fluid is filled; the housing having a hermetic structure except for a shaft insertion hole receiving the shaft therein and in which there is defined between the outer surface of the shaft and the inner surface of the shaft insertion hole a gap having a sufficient width to prevent the viscous fluid filled in the housing from leaking to outside, wherein the end portion of the housing where the thrust bearing is disposed is formed from a synthetic resin and joined by welding to the housing body also formed from the synthetic resin and in which the radial bearing is disposed, wherein the thrust bearing supports a projecting portion formed at one end of the shaft and which is larger in diameter than the shaft body, and has formed in the surface thereof opposite to the projecting portion of the shaft dynamic pressure producing recesses to produce a dynamic pressure by the viscous fluid.