Which motor is normally free from mechanical and magnetic vibrations?
Right Answer is:
The hysteresis motor can be considered as a self-starting synchronous motor. From the time of starting until it reaches synchronous speed, the motor produces a synchronizing torque and an ideally flat speed/torque characteristic. Due to the absence of slots and teeth on the rotor, the operation of this motor is smooth and quiet. Since the rotor has no salient poles or windings of any sort, the hysteresis motor is extremely quiet in operation and free from mechanical and magnetic vibrations.
The motor behavior is similar to that of a conventional synchronous motor but there is no excitation winding on the rotor or permanent magnets, giving the motor a high efficiency and power factor. These characteristics make it ideal for many industrial applications, such as in electronic and medical equipment, tape and video recorder drives, computer drives, clocks, gyroscope rotors for inertial navigation, robotics, and other special applications where precision and reliability are required.
Since the rotor has no salient poles or windings of any sort, the motor is extremely quiet in operation and free from mechanical and magnetic vibrations. Hence, a hysteresis synchronous motor is ideally suited for driving.