Stabilization of the movement speed of the output link of the hydraulic actuators in the volumetric hydraulic drive

Abstract

In a volumetric hydraulic drive the speed control of the hydraulic actuators output link is provided by changing the working volume of the pump (VOLUMETRIC CONTROL) or by changing of the hydraulic resistance of the lines (THROTTLE CONTROL). The latter provides for installation of an adjustable throttle in the pressure or drain line for hydraulic motor (sequential primary or secondary regulation), as well as, a controlled bypass of the pump supply into its suction line. Since during the throttle control of the speed of an output link of the hydraulic motor, load determines the pressure drop across the throttle and, therefore, the volumetric flow rate in the line, this control method cannot ensure the invariance of the volumetric hydraulic drive to the load on the actuator, which is necessary if it is used to rotate or to provide the antenna scanning for the radar stations and also the radar for the mobile above-water and land transport systems, that having a high sailing are exposed to significant contrary and fair wind load. In this case, the high quality of the stabilization of the loaded output links rotation speed is possible only in the case of using instead off a throttle the flowcontrollers. At the same time, it should be noted, that in the conditions of the more strict requirements for the control accuracy oblige to use the servo-hydraulic drive with the negative feedback in angular velocity of the output shaft rotation. Authors of the proposed article are consider the design features of some typical 2- and 3-linear flow controllers and also carried out a set of experimental studies of volumetric hydraulic drive with throttle control, provided 3-linear flow-controller, as a result of which the kinematic and dynamic characteristics of the volumetric hydraulic drive with a changing load on the output link at main and additional (secondary) hydraulic motors were obtained. The received results of experimental studies allowed for this article authors elaborate the adequacy of the developed mathematical model of a 3-linear flow-controller and to offer methodological recommendations for determining the parameters of its own components. In the conditions of limited availability of information on the design features and methodology of the flow-controllers, the results of experimental studies and proposed mathematical model of a 3-linear flow-controller can have some value in developing designs of flow-controllers, determining the parameters of their component elements, as well as in the use the flow-controllers in the loadinvariant volumetric hydraulic drives.