PM Armature

Discussion in 'General Electronics Chat' started by PackratKing, Oct 25, 2009.

  1. PackratKing

    Thread Starter Well-Known Member

    Jul 13, 2008
    Very briefly: I ran across an unusual motor hardware config in a clothes washer, and wonder if this would be common to more applications.

    The pump to eject water after a cycle, was constructed with two rather powerful ceramic magnets on the armature [ brushless ] in a wound stator, 120v ac ....... It had a really respectable torque for its size, and did not seem to be affected much by a locked-rotor, due to the pump being clogged by lint. I have seen many other lesser motors fried to a crisp in short order under those circumstances.

    Anyone else ever run across these ??
  2. BillB3857

    Senior Member

    Feb 28, 2009
    How many wires feed the stator? My guess is 3 or 4. Three would indicate a 3 phase brushless or 4 would indicate 2 phase brushless. There will be an electronic circuit board which will generate the proper power and phasing to drive the motor. Usually it will be of variable frequency to provide acceleration.
  3. PackratKing

    Thread Starter Well-Known Member

    Jul 13, 2008
    Little stinker is a real performer. My daughter has the machine, [ tho' currently down with a split plastic tub, well worth repair parts ]

    I will have to go back and get some pix of the actual hookup, and the machines' wiring diag. It definitely isn't 3-phase, and the ol' man don't recall any fancy circuits for it, just straight 120v ac off the cycle timer.......there may be a transformer in there somewhere, but it escapes me how it would drive a pm armature offa anything rectified......

    Quote the Terminator............I'll be back
    Last edited: Oct 26, 2009
  4. rjenkins

    AAC Fanatic!

    Nov 6, 2005
    I'd guess it is straight AC, two-wire, a symmetrical pump casing (rather than 'snail' shape) and bidirectional.

    If it's the style I'm thinking of, the pump impellor will have some rotational 'slop' on the shaft - I think the idea is if it does not start one in one direction, the rotor can turn a fair amount without any load to give the impellor a 'kick' and get it moving.