The induction motor has two main components, the stator and the rotor.
The stator carries three separate insulated phase windings which are spaced 120 degree (electrical) apart and lying in slots cut into a laminated steel magnetic core.
This type of stator winding is similar to the construction used for an a.c. generator.
The ends of the stator windings are terminated in the stator terminal box where they are connected to the incoming cable from the three-phase a.c. power supply.
The rotor consists of copper or aluminium conductor bars which are connected together at their ends by short-circuiting rings to form a cage winding.
The conductor bars are set in a laminated steel magnetic core. The essential reliability of the induction motor comes from having this type of simple, robust rotor which usually has no insulation on the conductor bars and does not have any troublesome rotary contacts like brushes, commutator or slip rings.