Nippon Seiko Kabushiki Kaisha

Nippon Seiko K.k.

Hiromitsu Asai

Hiromi Sugi

Kyozaburo Furumura

Yasuo Murakami

Takashi Nagato

Kiyoshi Haginuma

Toshimi Takajo

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.

Bearing with dynamic pressure grooves and method for manufacturing the

A dynamic pressure type bearing is applicable to a precision mechanical equipment. The bearing includes a hollow inner cylinder to fit a rotatable shaft. The inner cylinder is made of a thermosetting resin containing a 5 wt % to 75 wt % heat treated phenol resin powder and a 5 wt % to 75 wt % silicon dioxide, the total content of the phenol resin powder and the silicon dioxide being 50 wt % to 80 wt %. A spindle unit includes the bearing and a spindle made of an alloy containing aluminum as a main element. The bearing has a superior wear resistance, frictional characteristic and molding accuracy of the inner cylinder. The superior frictional characteristic of the inner cylinder allows a relatively soft spindle to be used in a spindle unit.

Dynamic pressure type bearing and spindle unit

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.

Sealing and bearing means by use of ferrofluid

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.

Construction of the mating sliding members in a linear feeding means

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.

Growing community of inventors

Fujisawa, Japan

Hiromitsu Asai