AC machines do not need a commutator. A commutator converts ac to dc and vice versa.

Do AC motors use commutators?

Commutators and brushes are used on all DC generators and DC motors. They are also used on some AC motors such as the repulsion, synchronous, and universal motors. ... The commutator on the DC generator converts the AC into pulsating DC.

Why commutator is not used in AC motor?

The main purpose of commutator is only to convert Ac to DC or vice versa, But in case of alternaters Commutator is not required because output will be AC only not DC. In case of DC generators Generation is AC so by using commutator will convert the AC to DC.