Noise Optimization in Balanced Hydraulic Vane Type Steering Pump

The investigation of fluid-borne noise in the balanced vane type hydraulic steering pump is focused in this study, which is the main source of noise in the hydraulic steering system of commercial vehicles. Turbulence development at the suction connection point to the bypass hole is the source of the noise. This creates a greater pressure ripple in the fluid flow, which leads to a low pressure zone at the Cartridge Inlet Region (CIR) within the pump housing. This creates a cavitation and results in fluid borne noise and further transmits as airborne noise.

The different factors like pump operating speed, pressure, bypass geometry, suction passage volume and its geometry have been examined in this study using computational fluid dynamics (CFD). It is observed that the modified parameters such as suction passage geometry and its conduit capacity and the diameter and angle of the bypass hole are the features involved in decreasing the fluid borne noise generation.

The optimization is performed in pump housing suction passage geometry in the form of cylindrical shape and angular bypass hole with increased volume. The simulation results indicate that the pressure at CIR increases substantially above 90%, thus the cavitation effect is reduced and the expected level of reduction in airborne noise is about 15%.

Finally, it is concluded that based on the CFD analysis with the improved configuration level of reduction in airborne noise is expected about 88 dBA at 2000 rpm and 50 bar static pressure, which is much below the customers threshold limits.