Abstract: At least one of surfaces including the raceway of an inner ring, the raceway of an outer ring, and at least the rolling surfaces of rolling elements is made of a steel containing nitrogen within the range of from 0.2 to 5.0 wt. % and chromium within the range of from 7.0 to 25 wt. %.

Abstract: A bearing with dynamic pressure grooves includes an outer cylinder made of a metal and a resin sheet bonded to the inner peripheral surface of the outer cylinder. The resin sheet is made of a thermoplastic resin, for example, a polytetra fluoroethylene, as a main component mixed with a wear-resistant improving material, for example, graphite or the like. The resin sheet is formed with a pattern of dynamic pressure generating grooves formed in an inner surface by plastic work. The pattern of grooves is varied depending on the types of relative movement between the outer cylinder and a shaft body, i.e., whether an axial linear movement, a rotational movement, or a spiral movement.

Abstract: A housing has a vertically extending cylindrical bore, with a radical bearing surface formed on the inner peripheral surface, and a thrust bearing surface formed on the inner bottom surface of the cylindrical bore. A shaft member which is supported rotatably in the cylindrical bore of the housing has a radial receiving surface and a thrust receiving surface respectively formed on the outer peripheral surface and the bottom surface. A dynamic pressure generating groove of a spiral shape is formed in at least one of the radial bearing surface and ther radial receiving surface. When the shaft member is rotated, a gas in the housing is sucked by the pumping action of the dynamic pressure generating groove and flows into a pressure chamber between the thrust bearing surface and the thrust receiving surface through a radial space between the radial bearing surface and the radial receiving surface. The pressure in the pressure chamber maintains the shaft member in a floating position by a predetermined amount.

Abstract: Sealing and bearing means by use of ferrofluid, in which a magnet is utilized effectively in cooperation with grooves engraved on one surface thereof, the grooves having the function for generating the dynamic pressure of the ferrofluid. The ferrofluid is retained in a gap between a rotary shaft and a magnet of cylindrical or disc type enclosing the rotary shaft concentrically. The magnet performs excellent two functions of bearing and sealing respectively.

Abstract: In an assembly of linear feeding means in which a carrying or carriage member is supported on a rod shaped supporting member and these two members can be relatively moved in lengthwise direction, a plurality of recesses each having a shape or arrow head are disposed such that the tip end of each of the arrow head type recesses is directed to either one direction or to the other opposite direction of the relative movement of the assembly.By virtue of this construction, hydrodynamic pressures are directed in both directions as to ensure smooth running of the assembly.

Abstract: This invention relates to sealing and bearing means by use of ferrofluid, in which a magnet is utilized effectively in cooperation with grooves engraved on one surface thereof, the grooves having the function for generating the dynamic pressure of the ferrofluid. The ferrofluid is retained in a gap between a rotary shaft and a magnet of cylindrical or disc type enclosing the rotary shaft concentrically. The magnet performs excellent two functions of bearing and sealing respectively.