Session: 01-02: Pumps and Motors 1: Piston and Membrane Machines

Paper Number: 140112

140112 - Comparative Study on Asymmetric and Symmetric Configurations of Valve Plates in Axial Piston Pumps 

Abstract: 

Instead of symmetric cylinders, using asymmetric cylinders is one novel method of reducing the size and weight of electro-hydrostatic actuators (EHAs). However, asymmetric cylinders have the flow mismatch between the rod and rodless chambers. Researchers proposed using the three-port asymmetric valve plate instead of the traditional two-port symmetrical valve plate in the axial piston pump to solve the flow mismatch problem. An additional port added to the asymmetric valve plate is directly connected to the accumulator of EHA, which can compensate for the flow difference between the rod and rodless chambers of the asymmetric cylinder. Although the asymmetric valve plate can effectively solve the flow mismatch problem caused by the asymmetric cylinder without increasing the weight and volume of the EHA, compared with the traditional symmetric valve plate, the effect of the asymmetric valve plate on the performance of the axial piston pump has been less studied. This paper establishes a mixed lubrication model of the cylinder block/valve plate interface oil film that considers the asperity contact, and comparatively analyzes the oil film characteristics of asymmetric and symmetric valve plates. It is found that the cylinder overturning behavior caused by the asymmetric valve plate is more prominent than that of the symmetric valve plate. At the same time, by establishing a lumped parameter model of the axial piston pump, the flow and pressure characteristics of asymmetric and symmetric valve plates under different operating conditions are comparatively analyzed, revealing the effect of asymmetric valve plates on the flow and pressure ripple of the axial piston pump. The reseach achievement  in this paper can be utilized to optimize the cylinder anti-overturning behavior and outlet ripple suppression of the piston pump, as well as to improve the control performance of the EHA.

Presenting Author: Yijie Lu Zhejiang University

Presenting Author Biography: Yi-jie Lu,born in 1999, received the B.S. degree in mechanical and electronic engineering from Lanzhou University of Technology, Lanzhou, China, in 2021. He is currently working toward the Ph.D. degree in mechatronic engineering with the College of Mechanical Engineering, Zhejiang University, Hangzhou, China.His research interests include piston pump, fluid mechanics, lubrication interface.

Authors:

Yijie Lu Zhejiang University
Hua Fang Zhejiang University
Bo Yang Zhejiang University
Haoyi Jiang Zhejiang University
Zhenfei Ling Zhejiang University
Hao Liu Zhejiang University
Xiaoping Ouyang Zhejiang University
Huayong Yang Zhejiang University