Patent ID: 9030069
Filing Date: 2015-05-12
Classification: F16C,H02K

Abstract:
1. A hydrodynamic bearing assembly comprising: a shaft; a sleeve disposed to be spaced apart from the shaft by a predetermined interval to form a bearing clearance therewith; and a thrust member installed on the shaft, wherein at least one of the shaft, the sleeve, and the thrust member is provided with a dynamic pressure groove for generating fluid dynamic pressure in a lubricating fluid provided in the bearing clearance, one side of a portion of the dynamic pressure groove into which the lubricating fluid is introduced is provided with a pressure reduction preventing groove for suppressing a reduction in pressure generated at the time of introduction of the lubricating fluid, the dynamic pressure groove includes upper and lower journal grooves formed in at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve, the upper and lower journal grooves have a herringbone or spiral shape, the pressure reduction preventing groove is disposed to one side of a distal end portion of at least one of the upper and lower journal grooves in a direction opposite to a rotation direction of the shaft or the sleeve so that the lubricating fluid is introduced into the pressure reduction preventing groove before being introduced into the upper and lower journal grooves, the pressure reduction preventing groove comprises one or more pressure reduction preventing grooves disposed to be spaced apart from each other in the direction opposite to the rotation direction of the shaft or the sleeve, and the one or more pressure reduction preventing grooves decrease in size in a direction away from the upper and lower journal grooves.