Control and Dynamic Characteristics Analysis for the Double-Compound Axial Piston Pump Based on Working Conditions

Abstract

The periodic flow and pressure pulsation of the axial piston pump can lead to periodic vibration, noise, and even damage to various components in the hydraulic system. Therefore, the dynamic characteristics analysis of the axial piston pump in the hydraulic system is of great significance for reducing vibration and noise in the hydraulic system and improving efficiency. The double-compound axial piston pump is the key component of a high power and large flow hydraulic power system, which has a special power control mode. In this paper, the working and control principles of the double-compound axial piston pump are analyzed, the numerical model of the double-compound axial piston pump is established, and the effectiveness of the model is verified through experimental tests. The constant power control characteristics of the double-compound axial piston pump under different power settings and the variable power control characteristics under the rated load pressure are analyzed. By analyzing the dynamic characteristics of the double-compound axial piston pump, the influence of different working conditions on the dynamic characteristics is investigated. The results show that the output efficiency of the double-compound axial piston pump is higher when the output flow is larger. When the piston chamber works in the closed pre-compression pressure zone and the closed pre-release pressure zone, oil backflow occurs. The oil backflow in the piston chamber seriously intensifies the outlet flow pulsation of the double-compound axial piston pump. The flow pulsation rate is positively correlated with load pressure and power control pilot pressure, while negatively correlated with spindle speed. The paper provides a basis for the analysis and optimization of power control, flow pulsation, fluid vibration, and noise of the double-compound axial piston pump.

Digital Control Method and Performance Analysis of the Double-Compound Axial Piston Pump

“…The original mechanical-hydraulic feedback servo control method mainly adopts a cross-power control mode, and its control mainly relies on the cooperation of the power control valve and the dual power control springs. The detailed control principle and characteristics have been described in a previous study . Under this control method, the main pump flow can only be adjusted on the constant power control curve, and the flow control curves under different set output power can be selected by controlling the pilot pressure.…”

“…Then, the numerical simulation model of the digital control DCAPP is established. The specifications of the main pump and the properties of the hydraulic oil are shown in Tables and . The model is composed of the axial piston pump body submodel, the controller submodel, the variable control submodel, the simulated loading submodel, and the simulated data collection submodel, as shown in Figure .…”

“…A variety of sensors are installed on the test bench, as shown in Figure , which are used to measure the shaft speed, shaft torque, outlet flow, outlet pressure, leakage flow, etc. The technical characteristics of the sensors are shown in Table . The test bench allows the tested pump to adjust the shaft speed, load pressure, pilot pressure, etc.…”

“…Due to the advantages of tight structure, high working pressure, high power density, high volumetric efficiency, and easy variable realization, the double-compound axial piston pump (DCAPP) is often used as the main power source of high-pressure, high-speed, and high-power hydraulic systems. , Two axial piston pumps are installed symmetrically, sharing an intermediate of oil supply and discharge to form a series of shafts . The DCAPP with traditional mechanical-hydraulic feedback servo control is equipped with two variable controllers to control the front and rear pumps, which can realize a common oil supply and separate oil supply for one or more working devices.…”

Resonance Suppression of a Controllable Mechanism Welding Robot End with Central Composite Design Methodology

“…In the process of operation, vibration inevitably occurs in the welding robot system due to multi-source excitation such as the motor drive and welding gun impact vibration. The vibration level of the welding robot directly affects the welding quality [5], and the suppression of resonance has become an important research direction [6][7][8]. Therefore, controlling the suppression resonance is an important consideration in the design and development of welding robots [9,10].…”