motors????

Question

what are induction motors??????????

please ansr

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Answer 1

Check out this site on Wikipedia--it's pretty cool!

http://en.wikipedia.org/wiki/Induction_motors

Answer 2

In all electric motors torque is caused by the action of two (or more) magnetic fields pulling (and/or pushing) on each other. If the motor has windings on both the rotor (the shaft part) and the stator (the fixed or frame part) then the electrical connections to the rotor windings must be made through mechanical devices known as 'brushes' and 'slip rings'. The kindest thing you can say about brushes is that they do work. But they also wear (rather quickly) and they almost always spark (which causes lots and lots of electrical interference)

The 'induction' motor (which was invented by Nikola Tesla way back in 1888) solves this problem by using the magnetic field(s) created by the stator windings to induce a current in the rotor windings to provide the needed magnetic field in the rotor. This is very similar to the way a transformer works and, in fact, an induction motor can be thought of as a sort of 'rotating transformer'.

The downside of this is that the induction motor only works with AC. But, considering the reduced maintenence and nearly zero electrical interference, it's not a big downside. Essentially all AC electric motors today are of Tesla's basic design. He was one *very* bright lad

There's another problem with induction motors and that is that the 'transformer' effect doesn't begin to work well until the moter is up to about half of it's normal RPM's. This problem is especially troublesome in smaller motors (under a few horsepower)

To solve this problem a variant, called the 'split-phase' induction motor, which has an 'auxilary' stator winding that helps to provide torque at lower RPM was invented. When the motor gets to about 50% of its operating speed, a centrifugal switch upens the auxilary winding.


Doug

Answer 3

An induction motor uses a communtator & brushes to power the motor.
THe motor can is lined with at least 2 different magnets.
The contact of the brush with the communtator causes the field to switch & "induces" the shaft to begin to rotate.
THe timing of the switching is slightly advanced so as to stay ahead of the switching fields.