Product Manual

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, see Chapter IX.
Brakemotors
A brakemotor is a 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 manufactur-
ing 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 con-
trol. Usually, they are part of open-loop control systems, meaning there
are no feedback devices.
A three-phase brakemotor. Note
the brake on the fan end. Like
many brakemotors, this model has
a NEMA C face for direct mounting
to the equipment to be driven.
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