Research On Double Stator Pump Controlled Asymmetrical Hydraulic Cylinder System

The hydraulic cylinders that are widely used today mainly include symmetrical cylinders and asymmetric cylinders.The flow rates required for the separate working of the symmetrical cylinders are the same,and the volume control of the symmetrical hydraulic cylinders can be easily realized.However,due to the unequal working area at both ends of the asymmetric cylinder,the flow required by the hydraulic cylinder during the extension and retraction is inconsistent,so that the movement of the asymmetric cylinder in both directions is not linear.This problem is a key technical problem for volumetric control of asymmetric cylinder systems.This paper proposes a flow compensation scheme for volumetric control of asymmetric hydraulic cylinders,which fundamentally compensates for the asymmetric flow of the two chambers.Starting from the structural characteristics and working principle of the double stator pump,the feasibility of the double stator pump in the volumetric control asymmetric cylinder system is explored in detail.This paper first completed the design of the dual stator pump,determined the specific parameters of the core components,and optimized the pump from the perspective of vibration and noise reduction.In this paper,three kinds of dual-stator volume control asymmetric cylinder systems are proposed.Three control schemes can compensate the asymmetric flow at both ends of the asymmetric cylinder.After comprehensively coMParing the three control schemes,it was decided to select the system of permanent magnet synchronous motor to drive the double-acting roller connecting rod double stator pump as the in-depth research object.After analyzing the control principle of the system,the mathematical model of the motor is constructed,and the principle of speed regulation under the vector control of the permanent magnet synchronous motor is explored.In this paper,the principle of the system loop is analyzed in detail,and the compensation principle of the two-cavity flow of the asymmetric hydraulic cylinder is studied from the aspects of pump cylinder connection,two working conditions and matching principle.The various leakage modes of the double stator pump are analyzed.The actual matching relationship between the double stator pump and the asymmetric cylinder under the leakage is considered,and the actual flow ratio is simulated to obtain the factors affecting the selection of the asymmetric cylinder parameters.After that,the mathematical models of each part of the system are constructed to analyze the power consumption of the system.Finally,the experimental parameters were determined,and the compensation principle of the double stator pump in the asymmetric cylinder system was verified.The asymmetric hydraulic cylinder system under the control of the double stator pump has achieved the same control effect as the symmetric hydraulic cylinder,which simplifies the system structure,reduces the system energy consumption,has no overflow throttling loss,and has a convex energy saving effect.High response characteristics of servo motors.