Analysis of Frequencies in Steering Systems Tubes By Pressure Peaks In Bench Test

One of the most common complaints about noise in small vehicles is related to the hydraulic steering pump, which is strongly used during parking maneuvers, and produces a noise that overcomes the one coming from the engine, due to its low speed. This noise can be eliminated by the introduction of two resonators inside the high-pressure tube designed to coincide with the tube's resonance frequency. Here I present a bench test for measuring and evaluating the resonance frequencies of high-pressure tubes of hydraulic steering systems with and without resonators, and the resulting attenuation level of the steering pump noise by measuring the pressure peaks at the entry and outlet of the tube. Adopting this bench test eliminates some confounding variables that can interfere with the measurement such as engine vibration, others components' frequency orders (the engine itself, compressor, alternator, etc.), speed control, among others. Through this bench test it is possible to evaluate the hydraulic steering system in isolation, to speed up the pump by a constant acceleration and to collect the data on pressure peaks by FFT for posterior analysis. In this paper I present the bench test and the results obtained with a tube with and without resonators, in comparison with the predicted results.