Abstract: A three-phase coil structure (30) having a two-phase coil set (32) including a plurality of rectangular air-core coils arranged side by side so as to be adjacent to each other in the same plane includes a one-phase coil set (31) including two air-core coils having different sizes and bending angles bent at both ends and disposed to straddle adjacent long sides of the two-phase coil set (32), wherein a number of turns of each of the air-core coils of the one-phase coil set (31) is larger than a number of turns of each of the air-core coils of the two-phase coil set (32).

Abstract: 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.

Abstract: 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.

Abstract: An apparatus for protecting a linear motor having a structure in which permanent magnets and a coil are subjected to relative movement, comprising (a) a means for detecting current flowing through said coil, (b) a multiplying means for calculating the squared value of the detected current every constant time &Dgr;t, (c) a memory means receiving said squared values for successively storing said squared values from the first one to the nth one, the first squared value being eliminated when the (n+1)th squared value is input, and the same operation being repeated subsequently, (d) an adding means for calculating the total of n squared values in said memory means, (e) a means for setting a reference value, which is to be compared with the total of said squared values, (f) a means for comparing the total of said squared values with said reference value for outputting an overload signal when said total has become larger than said reference value, and (g) an overload-preventing means receiving said overload sig

Abstract: An apparatus for protecting a linear motor having a structure in which permanent magnets and a coil are subjected to relative movement, comprising (a) a means for detecting current flowing through said coil, (b) a multiplying means for calculating the squared value of the detected current every constant time &Dgr;t, (c) a memory means receiving said squared values for successively storing said squared values from the first one to the nth one, the first squared value being eliminated when the (n+1)th squared value is input, and the same operation being repeated subsequently, (d) an adding means for calculating the total of n squared values in said memory means, (e) a means for setting a reference value, which is to be compared with the total of said squared values, (f) a means for comparing the total of said squared values with said reference value for outputting an overload signal when said total has become larger than said reference value, and (g) an overload-preventing means receiving said overload sig

Abstract: There is provided a moving magnet type linear motor having a reduced magnetic gap and an improved motive force and adapted to down-sizing, wherein it comprises a stator B including a plurality of sequentially arranged coil assemblies 3 having coils 11 formed by winding self-fusion-adhesive conductive wires, a plurality of permanent magnets 2 arranged to show opposite polarities vis-à-vis with a magnetic gap G interposed therebetween and a moving element A including a yoke 1 rigidly fitted to said permanent magnets 2 and forming a magnetic circuit with said permanent magnets 2, said moving element A being movable along the direction of arrangement of said coil assemblies 3 contained in said magnetic gap G. Said stator B includes an upper coil frame 5 and a lower coil frame 6 for rigidly holding said coil assemblies 3 in such a way that the surfaces of said coil assemblies 3 are flush with each other.

Abstract: 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>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.

Abstract: 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.