4 Brush Perm Magnet DC motor help

Discussion in 'General Electronics Chat' started by makidoja, Jul 7, 2014.

  1. makidoja

    Thread Starter New Member

    Feb 1, 2012
    4
    0
    Hi

    I have a DC motor 12vdc 300w, which has 4 brush setup, the motor had a problem where all the magnets became unbonded from the housing, I have tried refixing the magnets but the motor has low power and pulls lots of current.

    the magnets are set out in 4 quadrants and the 4 brushes are 90 deg apart with opposing brushes being + and -

    I'm trying to understand if I have rebonded the magnets in the housing at the correct polarity, basically I have opposing magnets at the same pole like:-

    N
    S S
    N

    is this correct? If so I cannot understand why the motor has low power, and in some cases is the motor stops in a certain position it will not restart just pull lots of current.

    Thanks for any assistance

    Mak
     
  2. Alberto

    Active Member

    Nov 7, 2008
    169
    36
    This statement tells that you have re-assembled the magnets incorrectly!
    Tray to get info from the manufacturer or tray various logic combination till the motor still run normally.

    Cheers

    Alberto
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,553
    2,375
    +1 on the same.
    Max.
     
  4. makidoja

    Thread Starter New Member

    Feb 1, 2012
    4
    0
    Hi

    OK the manufacturer is not very helpful so was kinda looking for someone with some 4 brush DC motor knowledge.

    Mak
     
  5. bwilliams60

    Active Member

    Nov 18, 2012
    724
    89
    You have your magnets in incorrectly but you have the proper setup. The two norths should oppose each other and the two souths should oppose each other, so it should be N-S-N-S. My question is, how did you determine the polarities before you put them in? Are any of them cracked?
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    You may need to rotate the endbell with the brushes 90 degrees.
     
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