Development of a resonant piezohydraulic hybrid actuator

This paper proposes a piezohydraulic hybrid actuator driven by a resonant vibrator based on two rhombic micro-displacement amplifiers. The resonant piezohydraulic hybrid actuator consists of a resonant piezoelectric vibrator, a pump body, a manifold, a return valve, and an output cylinder. The vibration mode of the piezoelectric vibrator is simulated, and the working principle of the resonant piezohydraulic hybrid actuator is depicted. Then, the performance of the piezohydraulic hybrid actuator is experimentally investigated, and the effects of exciting frequency, exciting voltage, and bias pressure are analyzed. The results demonstrate that the hybrid actuator performs the best when the exciting frequency is near the resonant frequency; meanwhile, the higher the exciting voltage, the better the performance. Moreover, it indicates that a larger bias pressure will bring a larger reaction force to the vibrator and reduce the performance of the actuator system. The maximum blocked force and no-load velocity are 378 N and 4.8 mm/s, respectively, when the bias pressure is 1.5 MPa and the exciting voltage is 500 V_pp.