CORELESS LINEAR MOTOR

• Main Authors: HARADA TOSHIYUKI, TOMINAGA RYUICHIRO
• Format: Patent
• Language: English
• Published: 30.04.2004
• Edition: 7
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; DYNAMO-ELECTRIC MACHINES; ELECTRICITY; GENERATION

PROBLEM TO BE SOLVED: To provide a coreless linear motor wherein a side force can be reduced without an increase in cost. SOLUTION: The coreless linear motor comprises a fixed field and an armature 6. The fixed field is obtained by alternately disposing a plurality of permanent magnets 4 in one direction so that they are heteropolar to form individual field yokes 3, and disposing two rows of the field yokes 3 with a gap between so that the opposite permanent magnets 4 are heteropolar. The armature 6 has an armature winding 1 placed in a gap in the fixed field. In the opposite magnet-type coreless linear motor, a table 10 on which the armature 6 is fixed is disposed so that the table is movable in one direction. The linear motor is provided with a drive circuit. The drive circuit is positioned so as to be offset from the mechanical center of the gap in the armature 6 by a distance X. Further, the drive circuit shifts the phase of armature current relative to the induced voltage of the armature winding 1 at an electrical angle of π/2±α, thereby cancelling out the side force based on positional errors of the opposite permanent magnets 4 in the field portion. A value not more than 8° is taken for α, thereby generating the side force with substantially no influence on the effective thrust of the linear motor. COPYRIGHT: (C)2004,JPO