A hydraulic transmission system of a pump-controlled electro-hydraulic steering gear which is composed of a Hele-Shaw variable discharge pump, a single-opposed ram hydraulic cylinder and a block valve, was studied to investigate the steering performance under static and dynamic load disturbances.
It is shown that rudder response depends on the volumetric displacement coefficient of the pump, ram area and floating lever dimension. Hydraulic undamped natural frequency is defined and a dynamic stability criterion is derived from the system transfer function.
The magnitude asymptote of dynamic complience was derived, based on the frequency response analysis and experimental results show qualitative agreement within the given frequency range, 2 Hz to 26 Hz.
It is recommended that further study might be made on direct loading mechanisms to the tiller.
