A new approach to high-frequency electrohydraulic vibration exciter

An excitation means of electrohydraulic vibrator is proposed and aimed to enhance the working frequency. The vibrator is a symmetrical hydraulic cylinder controlled by a 2D valve, in which both rotary and linear motions of a single spool are used to vary the frequency and the amplitude independently. The frequency of the vibrator is proportional to the rotary speed of the spool and thus the high-frequency is achieved by increasing the rotary speed of the spool well lubricated in hydraulic oil. Experiments have been carried out to the vibrator loaded by an elastic force coming from the deformation of a frame work and the wave forms of the cylinder piston was measured. It is demonstrated show that the ascent and descent slopes of the wave form show some inconsistency which alleviates with the reduction of valve linear opening. The phenomenon is explained to be caused by the changing direction of the elastic force. Nevertheless, the wave from is close to a sinusoidal one. It is concluded the proposed method does point out an approach to the high-frequency excitation of the hydraulic vibrator.