Internal Gear Products
The Internal Gear, or Gear-Within-a-Gear pumping principle, has a motor driven rotor (outer gear) which drives the inner (idler) gear. As the teeth unmesh on the suction side, it creates voids which allow atmospheric pressure to force fluid in. Fluid is carried on both sides of a crescent, then the gears re-mesh on the discharge side to force fluid out. With only two moving parts, the design is elegantly simple and extremely reliable.
Internal Gear Pumps