Electrical – Oil on stator windings, commutator, and armiture

motor

So I took apart a circular saw, it was bone dry, pure metal to metal contact between the stator/commutator/armature.

However a refrigerator compressor seems to be different. It sucks oil from the bottom of the casing and sprays it all over the motor body getting the stator winding/commutator/armiture wet. Video can be seen here at the 3:25 mark: https://www.youtube.com/watch?v=3n8Kby6kgXc

In general, is it safe to put oil on stator windings/commutator/armiture, to help lube the contact surfaces? Reason I ask is I put a dab of oil in the circular saw between the armature and commutator and it started smelling really bad when turned on. How does it affect the life of the tool?

Best Answer

Your circular saw most likely has a AC/DC universal motor. This one has a commutator and contact surfaces. Avoid putting oil on the contact surfaces, it will burn from the bit of arcing which is unavoidable. Such surfaces are lubed with graphite, not oil.

A refridgerator compressor motor however is always a shaded pole asynchronous AC motor. It doesn't have any contact surfaces. So it's safe to lube it with oil.