Abstract: A hydrodynamic bearing apparatus comprises a shaft and a bearing having facing hydrodynamic surfaces therebetween. Hydrodynamic pressure generating grooves are disposed on at least one of the facing hydrodynamic surfaces of the shaft and bearing. The apparatus relatively rotatably supports the shaft and bearing by the hydrodynamic pressure from a lubricant fluid filled between the facing hydrodynamic surfaces. One of the shaft and bearing, on which the hydrodynamic pressure generating grooves are formed, are made of a metallic material whose thermal expansion coefficient is smaller than that of a copper containing material. A working layer made of the copper containing material is formed on the hydrodynamic surface side of the metallic material. The surface of the working layer functions as the hydrodynamic surface. The hydrodynamic pressure generating grooves are formed on the working layer.

Abstract: A sealing device for use in a motor. The motor, which maintains a shaft: and a frame that are interconnected by a bearing, includes a magnetic-fluid-seating device and a collecting device. The magnetic-fluid-sealing device seals the bearing with a magnetic fluid to prevent particles and fluids from escaping the bearing, whereas, the collecting device collects any particles and fluids which may escape the magnetic-fluid-sealing device.

Abstract: A hydrodynamic bearing apparatus which includes at least two hydrodynamic bearing sections for rotatably supporting a shaft member and a cylindrical member, where the bearing sections constitute a continuous bearing clearance. A hydrodynamic pressure generating portion is provided for generating a hydrodynamic pressure in a lubricant which is filled in the bearing clearance. One hydrodynamic generating portion is shaped asymmetrically to move the lubricant in one direction. Two capillary sealing sections are also provided. One capillary sealing section is positioned downstream in a moving direction of the lubricant and is configured such that the lubricant moves by a predetermined amount to cancel a differential pressure which is generated at the hydrodynamic bearing sections.

Abstract: A hydrodynamic bearing apparatus for use in a spindle motor. The bearing includes at least two hydrodynamic bearing sections for supporting a rotary member with respect to a fixed member, a hydrodynamic pressure generating mechanism, a space between the two hydrodynamic bearing sections, a lubricant, two capillary sealing sections, and a lubricant reservoir. In the hydrodynamic bearing apparatus, the hydrodynamic pressure generating mechanism is positioned at the hydrodynamic bearing sections, and the capillary sealing section of the two capillary sealing sections has a space capacity which allows for an increased amount of lubricant. The lubricant is moved by a predetermined amount in one direction by a differential pressure generated at the hydrodynamic bearing sections when the rotary member rotates.

Abstract: A method for inserting fluid in a bearing device containing a fixed member and a rotating member. The fixed member and the rotating member of the bearing device are assembled in a high pressure environment and subsequently placed in a low pressure environment. While in the low pressure environment, bearing fluid is placed in a space between the fixed member and the rotating member. The fixed member and rotating member along with the bearing fluid are then placed in the high pressure environment to fully disperse the bearing fluid in the space between the fixed member and the rotating member.

Abstract: A hydrodynamic bearing apparatus comprises at least two hydrodynamic bearing units which rotatably support a rotation member against a fixed member by hydrodynamic pressure of a lubricant filled in a bearing space. A thrust plate is adhesively bonded on one of the rotation member and fixed member to support the rotation member in an axial direction. The thrust plate and rotation member or fixed member form a junction. A mechanical bonding device bonds the thrust plate onto one of the rotation member and fixed member. A sealing agent prevents the lubricant from leaking from the junction between the thrust plate and the rotation member or fixed member. The sealing agent fills a space that communicates with the junction.

Abstract: A fluid bearing unit includes a shaft; a bearing; bearing fluid arranged between a shaft and a bearing which are rotatably engaged with each other so that they can be relatively rotated so as to generate dynamic pressure in the bearing fluid, wherein at least one of the bearing and the member for fixing the bearing unit is made of iron alloy having the volumetric magnetostriction of which acts to cancel the thermal expansion so as to become the coefficient of linear expansion thereof lower than that of the shaft.