Metric gears are defined by module, which designates the center-to-center distance between successive teeth

Gearmotors consist of an AC or DC motor with an integral gearbox or gear head that steps delivered speed up or down

Gearboxes and gearheads are speed reducers that consist of a set of gears, shafts, and bearings in an enclosed housing. In converting inputs to outputs, they reduce RPM and increase torque

Gear pumps use intermeshing gears to pump various types of liquids. Typically, one gear is the driver and the other is free wheeling. The gears have very tight tolerances so that the fluid being pumped cannot pass through them. Common uses for gear pumps include high pressure, metering, and flow control applications

Worm gears are cylindrical gears with a spiral thread that drive mating worm wheels in high-reduction gearset applications. They operate on non-intersecting perpendicular axes

Stepper motors use a magnetic field to move a rotor in small angular steps or fractions of steps. They provide precise positioning and ease of use, especially in low acceleration or static load applications

DC motors are most commonly used in variable speed and torque applications. They include brushless and gear motors, as well as servomotors

AC motors include single, multiphase, universal, induction, synchronous, and gear motors. They also include servomotors.  

DC servomotors are generally small and powerful for their size, and easy to control. Common types of DC servomotors include brushless or gear motors

Ratchets and pawls are mechanical gearing used to transmit intermittent rotary motion. They permit a shaft to rotate in one direction, but not in the opposite one

Electric linear actuators have an output rod that provides linear motion via a motor driven ball screw, lead screw, or ACME screw assembly. The actuator's load is attached to the end of a screw or rod and is often unsupported.

Industrial liquid handling pumps are classified in many different ways, and are distinguished by the media pumped and the fluid motive mechanism (dynamic or displacement).

Rotary positioning stages are devices with tables or shafts that may be rotated to any angular position. They may be driven or simple slides.

Air motors are powered by compressed air. They operate at relatively high speeds in industrial and spark-prohibited applications.

Variable transmissions are used in industrial applications to alter the speed of an output shaft.