2 C3873 GEROTER ASSEMBLY The basic geroter design uses a combination of mechani- cal and hydraulic principles that are utilized in the high torque, low speed motors. The outer ring ( fig. C153 ) of the geroler assembly is similar to an internal gear that is held in a fixed position by securing it to the motor housing. The rotating inner gear, called a star, orbits inside the secured outer ring. C153 Because of the different number of teeth on the star and outer ring, the star rotates in an eccentric circular orbiting motion from the housing center line. ( fig. C154 ) C154 2-24 DRIVE MOTOR 2.11 General Information