What causes loud humming noise in a permanant magnet dc motor and how to resolve it?

Posted by admin on February 23rd, 2010 and filed under card magnet | 2 Comments »

I have a pro-form treadmill. The drive is a variable speed dc motor. The motor has started making loud humming noise. I replaced the non-drive side bearing thinking that it might be the culprit. No luck. The motor makes noise even when it’s drive belt is removed and is spinning load free. The motor is pretty new and the controller card checks out good as per the voltage diagram. Any ideas?

make sure all the mounting bolts holding the motor are tight, you sure it’s the motor?feel around for the vibration causing the humming, it could be something loose attached near the motor. next, the bearings inside the motor could be bad. you could try grease. not sure if it would be cost effective to change those bearings as you may need a puller and press to change. watch your hair and clothing around spinning parts.

the transformer would humm with the power on and the motor off

2 Responses

  1. cs Says:

    make sure all the mounting bolts holding the motor are tight, you sure it’s the motor?feel around for the vibration causing the humming, it could be something loose attached near the motor. next, the bearings inside the motor could be bad. you could try grease. not sure if it would be cost effective to change those bearings as you may need a puller and press to change. watch your hair and clothing around spinning parts.

    the transformer would humm with the power on and the motor off
    References :
    industrial maintenance electrician

  2. jay p Says:

    is there a transformer converting ac to dc? common humming culprit.
    References :

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