As fuel prices continue to increase and emissions become more regulated, variable displacement vane pumps (VDV pumps) are gaining market share for their ability to reduce parasitic losses. VDV pumps vary the displacement per revolution by changing the centerline location of the outer slide relative to the inner rotor. The VDV pump is perfect in applications that do not require increasing fluid flow past a specific operating speed, thus reducing the parasitic losses associated to the higher pressure and fluid drag normally associated to higher operating speed.

Housing	Slide	Rotor

Gerotor pumps are ideal for engine, transmission and transfer case applications requiring tight packaging. By its design, a gerotor pump is a fixed displacement pump, meaning that the output of fluid per revolution is constant. The clearances between the inner and outer gerotors dictate the fluid losses (leakage), so stack-up tolerances are extremely critical. Additionally, the profile design of the lobes is key in controlling NVH in the pump. PMG has a proprietary lobe profile design which has proven to be quieter than competitors’ designs in high speed applications.