Analysis and test of a viscous pump with radial pumping grooves

Abstract

A new disk-type viscous pump utilizing multi-radial pumping grooves on its stator has been designed, analyzed and subsequently fabricated and tested. Analyses show that this new design pump exhibits higher flow rate characteristics than the recently reported multi-lobe design for the same pump size and rotor-stator clearances. Test results at rotor speeds of 600, 900, 1200 and 1500 rpm for a nominal rotor-stator clearance of 135 μm show the linear relationship between flow rate and discharge pressure for each speed, even though gradual increase in the working fluid temperature occurred during each test. This temperature increase can be the main practical problem in operating such a pump, along with maintaining very small rotor-stator clearances at high rotor speeds. Comparisons between the test results and the analytical predictions show good qualitative and quantitative agreements, especially for pump speeds of 600, 900 and 1200 rpm. For the present set-up, only low flow rate readings were obtained at a higher pump speed of 1500 rpm, since air entrainment occurred for higher flow rates at this speed. However, the experiment has shown that his new type of viscous pump is practically feasible.