Rotating drive especially for utility vehicles has a rotating spiral piston rod threaded through floating non rotating pistons with pressure seals

摘要

A compact rotating servo drive, especially for use on utility vehicles, has a spiral piston shaft (3) axially located each end in bearings and attached to servo arms (29). The spiral shaft has a flattened cross section and is threaded through one or more pistons (10) which are guide to move axially but cannot rotate. The pistons include seals (12). A simple design has the spiral shaft with two opposing threads, meeting in the center, and with two opposing pistons. The drive can be either hydraulic or pneumatic.