Patent ID: 6760187
Filing Date: 2004-07-06
Classification: F16C,G11B

Abstract:
A hydrodynamic bearing comprising:a fixed shaft having one end fixed to a base member; a disk-shaped flange member disposed in the proximity of the other end of said fixed shaft and through a hole of which said fixed shaft is penetrating; rotating members disposed so as to enclose said flange member and through which said fixed shaft is penetrating; and a motor having: a rotor unit attached to one of said rotating members; and a stator unit fixed to said base member so as to confront said rotor unit, wherein at least either of the confronting faces of one of said rotating members and said fixed shaft is provided with radial hydrodynamic pressure grooves, at least either of the confronting faces of said flange member and one of said rotating members is provided with thrust hydrodynamic pressure grooves, said radial hydrodynamic pressure grooves and said thrust hydrodynamic pressure grooves are filled with lubricant, relations of d12 and 0.2 mm&lE;d1âˆ’d2&lE;0.8 mm are satisfied, where â€œd1â€  is a diameter of a central portion where said radial hydrodynamic pressure grooves of said fixed shaft are formed or said radial hydrodynamic pressure grooves of said rotating member are confronted, and â€œd2â€  is a diameter of the other end portion of said fixed shaft beyond said flange member, and a clearance is secured between an outer circumferential surface of the other end portion having a diameter of â€œd2â€  and an inner circumferential surface of one of said rotating members confronting said outer circumferential surface.