Noise in hydraulic power steering systems is mainly generated by the hydraulic pump due to the cyclic pumping mechanism that creates pulsating flow transmitted by the fluid. This flow ripple and pressure ripple, propagating through the hydraulic circuit, interacts in a complex way with the other parts of the vehicle, generating audible noise inside the vehicle. The present work shows two ways to reduce the flow ripple amplitude generated by a vane pump through the redesigning of the pump rotating group. First, a nine-vane rotor pump is proposed and, secondly, a pump with three discharge ports is proposed. To check their results, a MatLab/Simulink based pump model was created according to the new geometrical characteristics and the results are compared with the regular pump ones. Also, a flow ripple experimental test was run using the Secondary Source Method to validate the numerical model results of the regular pump. The new designs simulation results show large flow ripple amplitude reduction (from 6dB to 16dB per harmonic) as well as frequency displacement in the discharge flow ripple spectra in both designs. Also, the simulations show perpendicular force on the pump shaft generated by the non-balanced conditions created by the new designs.
|Number of pages||14|
|Publication status||Published - 15 Sep 2010|
|Event||Fluid Power and Motion Control 2010 - Bath|
Duration: 15 Sep 2010 → 17 Sep 2010
|Conference||Fluid Power and Motion Control 2010|
|Period||15/09/10 → 17/09/10|