Design strategy and performance evaluation of novel miniature two-dimensional (2D) piston pump with a dual stacking mechanism

Abstract

Since the traditional axial piston pumps have limitations to fulfill the development demands of hydraulic pumps under the electrification trend and maintain a high volumetric efficiency within various operating conditions, a new two-dimensional (2D) piston pump is proposed. In this study, the novel structure and working principle developed to raise the power density and achieve better performance were comprehensively introduced. As the motions of rotary and reciprocating are employed together, the new pump can achieve the purpose of compact structure, a small moment of inertia, and self-balancing of reciprocating inertial force. In addition, an accurate flow area during the oil discharge process was re-defined. A nonlinear mathematical model of the instantaneous flow rate of the new 2D pump for evaluating leakage performance and volumetric efficiency was established and studied in detail. Moreover, crucial features for further improvement of working performance were discussed. Then, a prototype pump was made to experimentally measure the output flow at various load pressures (from 1 MPa to 8 MPa) and rotational speeds (from 1000 r/min to 6000 r/min). The volumetric efficiency was in a range of 91.27% to 99.21%. The results of simulations and experiments well demonstrated the capabilities of the proposed novel 2D pump.