Design And Research On Power-Recovery Hvdraulic Pump And Motor Test System With Mechanical Compensation

With the development of the electro-hydraulic proportional technology in the direction of high pressure, mass flow and high power, the application of hydraulic transmission technology is increasingly widespread. As core actuators of the hydraulic system, hydraulic pumps and motors have a direct impact on the static and dynamic properties of the whole system. However, traditional single-function test system can’t satisfy with requirements of diverse specifications, wide test items and complex working conditions of pump and motor. What’s more, traditional hydraulic pump and motor test system, under a non-load power recovery mode, wastes energy seriously and generates a lot of heat if applied to high-power component test, which results in decreased performance. While the power recovery hydraulic pump and motor test system, with changing trapped oil to give loads, is high-sensitivity, low-resolution and low-precision. In this thesis, a new power recovery hydraulic pump and motor test system with mechanical compensation giving loads with overflow valve and variable motor has been proposed, which has important engineering applications and research value.In this dissertation, through theoretical analysis and calculation, the design of the power recovery hydraulic pump and motor test system with mechanical compensation is completed. And based on AMEsim, numerical simulation for testing process is finished, analyzing load pressure characteristics, recycling efficiency and typical operating conditions of test system. At the same time, control strategy of changing system flow capacity with the method of adjusting the single variable displacement motor is analyzed with simulation. Finally, the measurement and control system based on Lab View and PLC is completed.The chapters of this dissertation are organized as follows.In Chapter 1, the development and research status of hydraulic pump and motor test system is analyzed at home and abroad. And a variety of power recovery hydraulic pump and motor test systems in typical loading ways are compared. Finally, the main research of this project is put forward.In Chapter 2, referring to national test standards of hydraulic pump and motor and combined with indicators requirements of the engineering project, the total design scheme of the power recovery hydraulic pump and motor test system with mechanical compensation is proposed, giving loads with self-assembly cartridge pilot proportional relief valve and variable motor. Finally, design and efficiency analysis of test system are completed.In Chapter 3, according to the design principles of the power recovery pump and motor test system and based on AMEsim, influences on loading characteristics of hydraulic pump test system in different conditions, such as parameters of overflow valve and displacement matching, are analyzed. And control strategy of matching the required minimum flow by adjusting the displacement of variable motor is proposed. Finally, typical working conditions for pump with some specification are analyzed with simulation.In Chapter 4, according to the design principles of the power recovery pump and motor test system and based on AMEsim, influences on loading characteristics and static performance of hydraulic motor test system are analyzed. In the similar way, simulation analysis of controlling overfalling quantity with traditional PED controller is finished. Finally, typical working conditions for motor with some specification are analyzed with simulation.In Chapter 5, According to the required process control, data acquisition and data processing in the process of test system, the overall design scheme of measurement and control system is put forward. And based on virtual instrument, the design of measurement and control system is completed, including control algorithm of PLC in lower computer and upper computer test software Lab View. Finally, the structure design of pump and motor test bench is completed.In Chapter 6, the main conclusions and achievements are summarized, and the further research work is put forward.