Математична модель динамічних характеристик силової частини електрогідравлічного приводу обертального руху

The mathematical model of the dynamic characteristics for the power part of the rotary motion electrohydraulic drive for technological equipment with volume regulation is presented. The considered power part of the hydraulic drive includes the volumetric pump with adjustable flow, auxiliary devices and the volumetric hydraulic motor. Two axial-piston hydraulic machines were used as the main pump and the hydraulic motor. To build the mathematical model, the settlement scheme is given and basic assumptions are made.The mathematical model of the dynamic characteristics for the power part of the electrohydraulic drive takes into account the inertia of the moving parts for the hydraulic motor and the compressibility of the working fluid in the pipelines and cavities of the pump and the hydraulic motor. The following basic assumptions are made. The electric motor rotates the pump shaft with an angular velocity, the value of which does not depend on the power developed by the pump. The hydraulic pressure actuator in the pipelines do not reach the values ​​at which the safety valves open. The pressure in the line before the make-up valves is kept constant. The loads overcome by the hydraulic motor are represented by the sum of the moments from the action of the inertial load, positional load and hydraulic friction brought to the hydraulic motor shaft. Pipelines are so short that fluid inertia and pressure loss due to friction can be neglected. The linearization of the mathematical model is performed, the transfer function for the rotation angle by the angle of inclination for the washer (cylinder block) is obtained. The adequacy for the mathematical model of the dynamic characteristics was verified by comparing the experimental and calculated transition processes for the angular velocity of the hydraulic motor shaft when applying voltage to the input of the electrohydraulic amplifier controlling the inclined washer (cylinder block). The proposed adequate mathematical model of the dynamic characteristics for the power part of the electro-hydraulic rotary drive is the basis for the further development of automatic control systems for technological equipment.