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The rotor for a hysteresis motor

The rotor for a hysteresis motor Correct Answer should have all above properties

  • Hysteresis motor:

  • Hysteresis motor is a synchronous motor with a uniform air gap and without DC excitation.
  • The torque in a Hysteresis motor is produced due to hysteresis and eddy current induced in the rotor by the action of the rotating flux of the stator windings.
  • The working of the motor depends on the working of the continuously revolving magnetic flux.
  • The stator winding remains continuously connected to the single-phase supply both at the starting as well as the running of the motor.
  • The rotor ring of the hysteresis motor made up of special magnetic material such as magnetically hard chrome or cobalt steel having a wide hysteresis loop.
  • The rotor of the motor is made up of a magnetically smooth chrome steel cylinder and it has no winding.
  • It has high retentivity and because of this, it is very difficult to change the magnetic polarities once they are caused by the revolving flux of the rotor.
  • This rotor of the hysteresis motor moves synchronously because the pole of the motor magnetically locks with the stator which has opposite polarities.
  • The rotor of the hysteresis motor consists of the core of aluminum or some other non-magnetic material that carries a layer of special magnetic material.

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  • The outer layer has several thin rings forming a laminated rotor.
  • The rotor of the motor is a smooth cylinder, and it does not carry any winding.
  • The ring is made of hard chrome or cobalt steel having a large hysteresis loop.
  • As it’s rotor is smooth and also it operates at constant speed (synchronous motor), the noise level hysteresis motor is very low as compared to the induction motor.
  • This type of motor is the smoothest running, quietest single phase motor and is used for quality sound reproduction equipment like record players, tape rewarded, etc. It is also employed electric clocks and other firming devices.

Related Questions

In the following question, sentences of a paragraph have been jumbled and labelled as A, B, C and D. You are required to rearrange the jumbled sentences of the paragraph and mark your response accordingly by selecting the correct option. A: An induction motor can, therefore, be made without electrical connections to the rotor. B: Three-phase squirrel-cage induction motors are widely used as industrial drives because they are self-starting, reliable and economical. C: An induction motor's rotor can be either wound type or squirrel-cage type. D: An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor needed to produce torque is obtained by electromagnetic induction from the magnetic field of the stator winding.
Consider the following statements: 1. A synchronous motor has no starting torque but when started it always runs at a fixed speed. 2. A single-phase reluctance motor is not self-starting even if path for eddy currents are provided in the rotor 3. A single-phase hysteresis motor is self-starting Which of these statement(s) is/are correct?
In case of synchronous motor, which of the following are true? a. Synchronous motor is not self-starting b. If the rotor poles are excited by field current and the stator terminals are connected to AC supply, motor vibrates. c. Variable frequency supply is used to start synchronous motor. d. By using frequency converter, a synchronous motor can be brought from standstill to its desired speed.
In a three rotor system, for the middle rotor, if the stiffness of both the length either side of the rotor is increased to two times what will be the effect on total stiffness of the middle rotor?
In a three phase induction motor of rotor impedance as (0.2+j0.2), rotor current in each phase lags behind the generated emf in that phase to rotor by a power factor angle of _________
A properly shunted center zero galvanometer is connected in the rotor circuit of a 6-pole, 50 hz wound rotor induction motor. If the makes 90 complete oscillations in one minute, the rotor speed is?
A center ammeter connected to the rotor end circuit of a 6-pole,50 Hz, induction motor makes 45 complete oscillations in a minute. Then the rotor speed and the speed of stator field w.r.t. rotor is?
Consider the following statements: In the above figure, the curves pertain to the DC motor A. Speed vs Armature current characteristic of a DC shunt motor B. Torque vs Armature current characteristic of a DC shunt motor C. Speed vs Armature current characteristic of a DC series motor D. Torque vs Armature current characteristic of a DC series motor
In a hysteresis motor, the rotor must have
The rotor of a hysteresis motor is made of