The Critical of the Components in the Vane Pumps

The Critical of the Components in the Vane Pumps .

The following components are critical in maintaining optimum performance of Keisters’ vane pumps The challenge each represents to the remanufacturer is detailed in the following pages.

A: Flex Plates (VQ)

The depth of metering and timing notches and lubrication grooves plays a vital role in VQ pump operation. As these steel- backed bronze plates flex, they eliminate the potential for pump seizure during cold start-up or at higher pressures. “Will fitters” often replace these plates with “look-alikes” without the same material composition. The result... erosion that generates contamination or ineffective protection against seizure. If plates are not made of the correct blend of materials, they will not “flex” properly. This can result in high heat and low volumetric efficiency.

B: Rotors

An old rotor will frequently have wider slots due to vane instability and/or normal wear over the service life of the component. In “will fit” products, rotor slot width is a critical dimension which we often find out of spec. “Will-fitters” will occasionally try to use thicker vanes to compensate for wider rotor slots. If thicker vanes are used, there may be higher vane tip loading on the ring contour and excessive ring wear could develop and result in early failure.

C: Vanes

Vane tip radius is very important in maintaining
the proper vane tip-to-ring contact pattern. Almost
all used vanes cannot
be reworked without weakening them or causing excessive contact stress between the vane and the cam ring. All vanes in a pump should be the same length. If they are not, vane breakage will occur and pumps will seize immediately. Keister uses new vanes in all vane pump cartridge kits.