Stepper motors are high pole count DC motors that are driven with a DC pulse train. Mechanical designers frequently create systems designed to use stepper motors at relatively high rpm based on the maximum motor speed rating (often 3000 rpm) and the motor torque vs. speed curves.
Unfortunately, they then often have difficulty achieving high motor speeds. The cause of this is usually that they do not pair the motor with an appropriate drive.
- Brushless – Stepper motors are brushless, which means they have high reliability with little maintenance. The commutator and brushes of conventional motors are some of the most failure-prone components, and they create electrical arcs that are undesirable or dangerous in some environments.
- Load Independent – Stepper motors will turn at a set speed regardless of load as long as the load does not exceed the torque rating for the motor.
- Open Loop Operation – Stepper motors move in quantified increments or steps. As long as the motor runs within its torque specification, the position of the shaft is known at all times without the need for a feedback mechanism.
- Holding Torque – Stepper motors are able to hold the shaft stationary.
- Excellent response to start-up, stopping, and reverse.
- Inherently more fail-safe than servo-controlled motors.