Investigation of the modes of motion of a hydraulic drive with axial-piston hydraulic motors at low speeds

Abstract

Technological machines for various purposes, in which hydraulic actuators are widely used, are constantly being improved in terms of power, speed and accuracy of the specified parameters. It requires making certain changes in the design of these actuators that allow them to withstand the operating modes of technological machines within the specified limits. The article considers the results of the study of the operation modes of a nonlinear hydraulic actuator with axial-piston hydraulic motors under the conditions of parametric excitation of self-oscillations due to the nonlinear nature of the friction moment in the front distributor of the hydraulic motor. The authors propose mathematical models of the modes of operation of this hydraulic drive at low speeds. They present a linearized mathematical model and the results of the study of this hydraulic drive in the form of amplitude-frequency characteristics obtained using the harmonic linearization of the dynamic equations. The results of the study allow us to estimate the parametric oscillations of the hydraulic actuator and to evaluate the minimum value of the constant component of the speed corresponding to the beginning of periodic intermittent motions, which leads to a decrease in the accuracy of performing technological movements of the actuators of technological machines.