Which part of a motor provides a means for power transmission?

The rotor, specifically the rotor shaft of a motor, plays a critical role in power transmission. It is the component that rotates and is connected to the load that the motor drives. When electrical energy is applied to the motor, the rotor experiences a force due to the interaction with the magnetic field produced by the stator, causing it to turn. This rotational movement is then transmitted through the rotor shaft to perform work on connected machinery or devices.

In the context of the other components:

The stator generates the magnetic field necessary for the rotor to rotate but does not transmit power directly. The end bell is primarily a structural component that houses and supports the motor parts but does not play a role in transmitting power. The commutator, found in some types of motors like DC motors, serves to reverse the direction of current flow in the rotor windings, helping to maintain rotation. However, as essential as the commutator is for the functioning of the motor, it does not directly contribute to the power transmission itself; that function lies with the rotor shaft.