Machine for tracing the profile of an orbiting star gear

摘要

A machine which may be used to either check or to machine the profile of an orbiting star gear for a gerotor type of fluid motor or pump is disclosed. The profile of a star gear is traced due to the interaction of a slide that carries a sensor, or a machining tool, in a back and forth direction toward and away from the star gear and in a second direction transverse to this back and forth direction with respect to a frame member. The slide is driven by an eccentric disc, at a rate which is determined in accordance with the number of teeth on the specific star gear in question. The combined motion of the star gear and the two slides causes the sensor, or the machining tool, to trace out the profile of the desired star gear for the purpose of either checking its profile, or of machining a new gear. A spring member is connected to the frame member to allow the frame member to move in a transverse direction but without rotation.