US 6,686,761 B2Granted

Method for determining whether a rotor is good in magnetic induction by measuring the EMF of a motor

AssigneeIndustrial Technology Research Institute

InventorsYann-Guang Pan, Jieh-Yee Huang, Li-Te Kuo, Shyh-Jier Wang

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Abstract

The invention pertains to a method for determining whether a rotor is good in magnetic induction by measuring the electromotive force (emf) of a motor. A standard stator of the motor is prepared as the standard of measurement. A set of induction coil is wound upon the standard stator so that when the rotor is combined with the standard stator and is subject to running by a driver, the induction coil can detect the back-emf signal generated by the rotor, by which the rotor quality can be determined. Since the measuring method disclosed in the invention is performed within the closed system composed of the rotor and the stator, the result is not only close to a real motor in rotation, the detection is simple and free from the problem of axis alignment. Thus, this method can increase the production efficiency of the product line.

Claims15

Dependent claims

A method for examining whether the magnetic property of a rotor is good by measuring the electromotive force (emf) of a motor and determining the quality of the motor rotor from the measured back-emf constant, the method comprising:

preparing a standard stator that contains at least a driving coil of one phase and at least an induction coil wound thereon;
combining a test rotor with the standard stator and providing at least a driving voltage of one phase to the corresponding driving coil on the standard stator using a driver so as to rotate the test rotor;
generating a back-emf signal from the test rotor and outputting the back-emf signal through the induction coil;
measuring the rotational speed of the motor;
computing the back-emf constant of the motor by dividing the back-emf signal by the rotational speed of the motor;
and
determining the quality of the test rotor by dividing the back-emf constant of the motor by the winding ratio between the driving coil and the induction coil.

4 more elements

Dependencies are inferred from the claim text.