Thrust ripple measuring apparatus and method in linear motor
AssigneeSumitomo Heavy Industries, Ltd.
InventorDaisuke Shinohira
Life of this patent
Estimating the term…
Abstract
In a thrust ripple measuring apparatus for use in a linear motor, a slave linear motor as a subject to be measured is coupled with a master linear motor through a non-contact type stage mechanism. A processing unit is supplied with speed-induced-voltages detected by a voltage detector and a moving speed of the slave linear motor detected by a speed detector and calculates a per-phase induced voltage constant from the ratio of the speed-induced-voltage of each phase and the moving speed and further calculates a thrust constant and a thrust ripple from the calculated per-phase induced voltage constant.
Claims8
A thrust ripple measuring apparatus in a linear motor, comprising:
- a master linear motor for driving a slave linear motor as a subject to be measured;
- a non-contact type stage mechanism for coupling the slave motor with the master motor;
- a voltage detector for detecting speed-induced-voltages generated in coils of the respective phases of the slave linear motor when the master linear motor is actuated;
- a speed detector for detecting a moving speed of a movable portion in the slave linear motor;
- and
- a processing unit supplied with the detected speed-induced-voltages and the detected moving speed;
- the processing unit calculating a per-phase induced voltage constant from the ratio of the detected speed-induced-voltage of each phase and the detected moving speed of the slave linear motor, and calculating a thrust constant and a thrust ripple from the calculated per-phase induced voltage constant.
A thrust ripple measuring method in a linear motor, comprising the steps of:
- preparing an apparatus in which a slave linear motor as a subject to be measured is coupled with a master linear motor for driving the slave linear motor through a non-contact type stage mechanism;
- detecting speed-induced-voltages generated in coils of the respective phases of the slave linear motor and a moving speed of the slave linear motor when the master linear motor is actuated;
- calculating a per-phase induced voltage constant from the ratio of the detected speed-induced-voltage of each phase and the detected moving speed of the slave linear motor;
- and
- calculating a thrust constant and a thrust ripple from the calculated per-phase induced voltage constant.
Dependencies are inferred from the claim text.