... and no commutator, carbon brush friction and spark. 2. The motor adopts high pole number, has no reduction gear, can directly ... lubricating oil leakage of the reduction gear. 3. The motor operates in constant current, the current doesn’t change under the conditions of start, noload ... , default phase and stucking, and the coil doesn’t burn out. 4. The motor adopts high pole number and has lower ...