Load-Sensing Pump Design to Reduce Heat Generation of Electro-Hydrostatic Actuator Systems

Qun Chao,Zongxia Jiao,Zhihui Li,Bing Xu,Junhui Zhang,Yaoxing Shang

doi:10.3390/en11092266

Abstract

The electro-hydrostatic actuator (EHA) with variable pump displacement is considered to be a promising alternative to the currently popular EHA with fixed pump displacement in terms of heat reduction. This paper presents a load-sensing pump for the EHA which requires no additional power source and can adjust its volumetric displacement automatically with load pressure. A load-sensing pump prototype was developed and experiments were carried out on a test rig for it under different operating conditions. In addition, an experimental campaign was performed on an EHA test bench with a load-sensing pump and a fixed displacement pump. The results show that the load-sensing pump can decrease its volumetric displacement automatically at high pressure and thus reduce the heat generation of EHA system effectively.

Highlights

Electro-hydrostatic actuators (EHA) have become popular in more electric aircrafts (MEA) with the development of power-by-wire (PBW) technology [1,2]
A typical electro-hydrostatic actuator (EHA) system consists of a bidirectional electric motor, bidirectional hydraulic pump, symmetrical hydraulic actuator, accumulator, and bypass valve [8,9]
The hydraulic pump used is often called an EHA pump [10], which is driven by the electric motor and provides pressurized fluid for the hydraulic actuator to power the flight control surface

Summary

Introduction

Electro-hydrostatic actuators (EHA) have become popular in more electric aircrafts (MEA) with the development of power-by-wire (PBW) technology [1,2]. The hydraulic pump used is often called an EHA pump [10], which is driven by the electric motor and provides pressurized fluid for the hydraulic actuator to power the flight control surface. It is common to vary the pump displacement by adjusting the swash plate angle using a hydraulic actuator controlled by a servo valve [22] This method has a fast response, but the additional hydraulic servo system makes the EHA system costly and complex. The volumetric displacement of the EHA pump can be decreased automatically as the load pressure increases, which effectively reduces the peak torque and heat generation of the electric motor. An EHA pump prototype was developed, and tests were carried out to verify the proposed load-sensing design

Mathematical Analysis

Relationship

Schematic

Discussion

Experimental