Method for operating a hydraulic device with pump and servomotor, and associated hydraulic device

Abstract

In a method for operating a hydraulic device for providing a supply to hydraulic consumers (V) on a plastics injection moulding machine, provision is made of a pump () with a volumetric delivery characteristic that results in cyclic pulsations and of a servomotor () with multiple poles that result in cyclic pulsations. The pressure at the hydraulic consumer (V) is detected and is input as an actual value into a pressure regulator () that readjusts the servomotor (), on the basis of a predefined pressure profile, to a pressure setpoint value at the hydraulic consumer (V). The cyclic pressure pulsation is minimized in that, by means of a rotational angle sensor (), the rotational angle (φ) of the pump () and/or of the servomotor () is detected and correlated with the cyclic pulsations, and in that, from this, a corrective value or a corrective function is determined and is transmitted to the pressure regulator () with control subordinate to the regulation of the pressure setpoint value. Alternatively or in addition, this is achieved in the case of a hydraulic device also in that, as corrective means for the pressure regulation, said means being subordinate to the consideration of the pulsations, the number of components of the pump () that result in the cyclic pulsations and the number of components of the servomotor () that generate cyclic pulsations are equal, or one is a multiple of the other.