数字型液压变压器设计及其稳态特性研究

Design of Digital Hydraulic Transformer and Experimental Research on Its Steady State Characteristics

提出一种数字型液压变压器(Digital hydraulic transformer,DHT),将多个二进制排量比的泵/马达流量单元组合在一起,利用机械连接使其同步转动。在各流量单元的进出口连接高速开关阀组,各阀组的通断状态对应着一个二进制数字,通过对进出口阀组状态数字的控制,可以调节变压比进而实现不同的压力输出。根据DHT的工作原理,进行结构设计和数学建模,并制造出样机,最后搭建试验平台对其稳态工作特性进行试验验证。结果表明,所提出的数字型液压变压器可以随着数字控制量的改变而变压,验证了其变压原理的可行性和实用性。DHT具有数字元件离散、简单和易控等特性且变压范围大,可以作为液压恒压网络系统中的二次调节元件驱动直线负载,还可以回收负载端的势能和压力能,对提高液压系统效率具有重要意义。

A digital hydraulic transformer(DHT) is proposed,which combines multiple binary displacement ratio pump/motor flow units together and uses a mechanical connection to make them rotate synchronously.A high-speed on-off valve group is connected to the inlet and outlet of each flow unit,and the on-off state of each valve group corresponds to a binary number.By controlling the digital status of the inlet and outlet valve groups,different transformation ratios can be adjusted to achieve different pressure output.According to the working principle of DHT,the structural design and mathematical modeling were performed,and a prototype was manufactured.Finally,a test platform is built to verify its steady state characteristics.The results show that the proposed digital hydraulic transformer can change its voltage with the change of digital control quantity,which verifies the feasibility and practicability of its voltage transformation principle.DHT has the characteristics of discrete digital components,simple and easy to control,and has a large voltage range.It can be used as a secondary regulating element in a hydraulic constant pressure network system to drive a linear load.It can also recover potential energy and pressure energy at the load end,which is of great significance for improving the efficiency of the hydraulic system.