Gearmotors

A gearmotor is made up of an electric motor, either DC or AC, combined with a geared speed reducer. o Spur, helical or worm gears may be used in single or multiple stages. 

The configuration may be either that of a parallel shaft, emerging  from the front of the motor, or a right-angle shaft. Gearmotors are soften rated in input horsepower; however, output torque, commonly a measured in inch-pounds, and output speed are the critical values. Gearmotors may be either integral, meaning the gear reducer and motor share a common shaft, or they may be created from a separate gear reducer and motor, coupled together. Integral gearmotors are common in sub-fractional horsepower sizes; separate reducers and

motors are more often the case in fractional and integral horsepowers.

For more on gear reducers and gearmotors. 

 A brake motor 

pre-connected package of industrial-duty motor and

fail-safe, stop-and-hold spring-set brake. In case of power failure, the

brake sets, holding the load in position. Brakemotors are commonly used

on hoists or other lifting devices. Brake features can also be added to standard motors through conversion kits that attach to the shaft end of either fan-cooled or open motor.

Motors for Precise Motion Control

These motors are always part of integrated motor-and-controller systems that provide extreme accuracy in positioning and speed. Common applications include computer-controlled manufacturing machines and process equipment. 

Servomotors are the largest category of motors for precision motion control. AC, DC brush-type, and brushless DC versions are

available. 

Closed-loop control systems, common with servomotors, use feedback devices to provide information to a digital controller, which in turn drives the motor. In some cases, a tachometer may be used for velocity control and an encoder for position information. 

In other cases, a resolver provides both position and velocity feedback. Step (or stepper) motors, which move in fixed increments instead of rotating continuously, provide another means of precision motion control. Usually, they are part of open-loop control systems, meaning there are no feedback devices.