Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

40 Chapter 1 Motor and Motion Control Systems
Figure 1-31 Cross-section of a
hybrid stepping motor showing
the segments of the magneticcore
rotor and stator poles with
its wiring diagram.
Hybrid stepper motors are available in NEMA size 17 to 42 frames, and
output power can be as high as 1000 W peak.
Stepper Motor Applications
Many different technical and economic factors must be considered in
selecting a hybrid stepper motor. For example, the ability of the stepper
motor to repeat the positioning of its multitoothed rotor depends on its
geometry. A disadvantage of the hybrid stepper motor operating openloop
is that, if overtorqued, its position “memory” is lost and the system
must be reinitialized. Stepper motors can perform precise positioning in
simple open-loop control systems if they operate at low acceleration
rates with static loads. However, if higher acceleration values are
required for driving variable loads, the stepper motor must be operated in
a closed loop with a position sensor.