Modeling and experimental study on a novel linear electromagnetic collaborative rectification pump

Abstract

A novel linear electromagnetic collaborative rectification pump (LCP) consisting of two linear electromagnetic drive oscillating pump units (LPUs) is presented in this paper. It is capable of producing high stroke by utilizing linear motor. Moreover, its novel collaborative rectification structure differs from check valve and active valve rectification measures used in conventional hybrid hydraulic pumps driven by smart materials. A mechanical linkage of piston and rectification valve's spool is designed along with coordination of two LPUs achieves the rectification of in-and-out flow at chambers’ ports. Collaborative rectification brings hydraulic coupling effect between two LPUs, which is analyzed in-depth. Moreover, the dynamic model consisting of motor, cylinder and valve is formulated analytically. Following that, a two-units decoupling method with mutual compensation is proposed to achieve synchronous and out-of-phase motions of the pistons. A research prototype of LCP along with test platform has been developed. Experiments are conducted on the output performance of the system. The result shows that the two-units decoupling method can improve the coordination of the two LPUs and the volumetric efficiency of the system significantly. The volumetric efficiency in different load condition and the bandwidth of LCP are got. A positive correlation between LCP bandwidth and the oscillating frequency of the linear motor are revealed.