Gear in rotor produces compact servomotor

Berger Lahr has developed an AC synchronous servomotor with a planetary gearbox built into its rotor. According to the company, this design results in a compact, lightweight machine that can produce high torques at speeds of up to 1,500 rpm while generating less inertia and backlash than a conventional geared motor.

Berger Lahr claims that its RIG (Rotor Integrated Gear) motor is up to 39% shorter and 41% lighter than a conventional combination of an AC synchronous motor and an attached gearbox.

The company - part of Schneider Electric since last year - expects the motor to be particularly attractive for robotics and pick-and-place applications. Because coupling elements are not needed, the drive assembly is more rigid, and therefore more accurate. Also the lower moving masses are said to improve the drive`s dynamic properties, while reliability is enhanced.