Direct drives, ie working without a gears manufacturers drives have, but in some cases benefits - there is no game and account for the losses of the transmission. As an example, the spindle motor may be mentioned.

As always above or below a gear ratio i, the speed ratio of input speed to output speed is understood. In addition to i are the efficiency, the maximum torque at the output, the game, the maximum speed and maximum axial and radial shaft load (force) are important parameters of a gear motor.

Gear types (one or more stages), which are mainly geared motors are used in:

     * Worm gear: the axis perpendicular to the engine output shaft rotational axis
     * Spur: axis of the output shaft is parallel, but offset to the motor axis of rotation
     * Planetary gear: axis of the output shaft of the motor-like rotating axis
     * Bevel: the axis perpendicular to the engine output shaft rotational axis

Continue to differ are rotary actuators and rotary actuators. In a rotary drive, the shaft turns as often, with a pivot drive less than a full rotation.

A feature of gear motors is whether they are irreversible or reversible, that is, whether the rotation is the drive shaft at no motor current possible. Epicyclical gears and spur gears at low speed reduction that is often the case, are self-locking worm gear in the rule.