This study presents a hydraulic step wave generator using a spool valve that is used to evaluate the dynamic characteristics of hydraulic components at low frequencies. The hydraulic step wave generator generated a hydraulic step wave with short rise time by suddenly opening a wide passage between the high- and low-pressure chambers. The pressure transient of the fluid of the low-pressure chamber in the generator was effectively restricted by its extremely small volume. Additionally, the reference pressure transducer was installed next to an input port of a test hydraulic component so that the reference transducer and the test component simultaneously received the same signals. Generator performance was evaluated at different pressures and volumes of the high-pressure chamber in the time domain. The experimental results show that the minimum rise time of the pressure transient is about 0.1 ms, which is shorter than that of current hydraulic wave generators. Hence, the generator could function as excitation for testing the dynamic characteristics of hydraulic components.
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