A coreless gear motor is a type of gear motor that uses a stator without a core, or an armature without a commutator. The windings are supported by the housing and the rotor. The rotor is typically a permanent magnet, but may also be an electromagnet.

The stator of a coreless gear motor is a simple ring of magnets or electromagnets, with the teeth of the gear cut into it, and the rotor is a permanent magnet or an electromagnet, with the teeth of the gear cut into it. The rotor turns inside the stator, and the teeth of the gear mesh, providing the mechanical power output of the motor.

The advantage of a coreless gear motor over a conventional gear motor is that there is no cogging effect, so the motor can start and stop more smoothly. The disadvantage is that the motor is less efficient than a conventional motor, because the magnetic field of the stator is not confined to the air gap between the stator and the rotor. In addition, coreless motors have several advantages over traditional brushed dc motors, including lower electromagnetic interference, and longer lifetime. A coreless gear motor is typically used in applications where smooth operation is more important than efficiency.