Hitachi Metals, Ltd.

Seiki Takedomi

Teruo Umehara

Kuninori Imai

Takeji Shiokawa

Osamu Kakutani

Yoshitaka Takagi

The linear motor includes a stator and a mover. The stator includes: a board part having a rectangular plate shape, a plurality of magnetic pole teeth which are juxtaposing to each other on the board part and around each of which a coil is wound, and an auxiliary tooth which is arranged in an end part of the board part in a juxtaposed direction in a manner of being separate from the magnetic pole teeth and around which a coil is not wound. The mover includes: a plurality of magnets whose tip surfaces face the stator, and a back yoke having a rectangular plate shape in which the plurality of magnets are aligned in a straight line such that magnetic poles are alternately formed.

Linear motor

In a linear motor having at least one pair of permanent magnet assemblies opposing each other via a gap therebetween, each of the permanent magnet assemblies is constituted by a plurality of permanent magnets, and each of the permanent magnets has, in a plane perpendicular to the moving direction of a movable member, a cross section satisfying the relation: Ac&gt;Ae, wherein Ac represents a cross section in a center portion of the permanent magnet and Ae represents a cross section at each end of the permanent magnet, to obtain a substantially sinusoidal magnetic flux density distribution. Preferably, the permanent magnet has on the side facing the gap a flat center surface and inclined flat surfaces positioned on both sides of the center surface.

A linear motor comprising a center yoke made of a ferromagnetic material; outer yokes made of a ferromagnetic material, having permanent magnets, each having magnetic poles on the inner and outer surfaces thereof and fixed to the inner surface of the outer yokes, and disposed outside the center yoke with both ends thereof being magnetically coupled; and a movable member having coils wound on the outer circumference thereof and axially movably disposed in a gap between the center yoke and the outer yokes, in which recesses are provided on the opposing surfaces of the center yoke and the movable member, and a static-pressure gas bearing is formed by providing an air intake vent connecting to these recesses.

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Fukaya, Japan

Seiki Takedomi