Abstract: A control device for a positive displacement pump includes a throttle device and a flow control valve. The flow control valve includes a flow control piston and is configured to regulate an unrequired excess flow of the pump at an increased speed. The throttle device is configured to produce a speed-related pressure differential in a bore section, the pressure differential being responsible for the displacement of the flow control valve and the throttle device. The throttle device is arranged in the pressure outlet (bore section) of the pump and includes a regulating pin connected to the flow control piston, having a control contour configured so that a modifiable through cross-section is created in association with a throttle bore. The control pin has a wider section in an axial displacement area of the throttle device, the area not being involved in control of the volume flow, whereby a minimum obturating section arises in the displacement area.

Abstract: A control device for a positive displacement pump includes a throttle device and a flow control valve. The flow control valve includes a flow control piston and is configured to regulate an unrequired excess flow of the pump at an increased speed. The throttle device is configured to produce a speed-related pressure differential in a bore section, the pressure differential being responsible for the displacement of the flow control valve and the throttle device. The throttle device is arranged in the pressure outlet (bore section) of the pump and includes a regulating pin connected to the flow control piston, having a control contour configured so that a modifiable through cross-section is created in association with a throttle bore. The control pin has a wider section in an axial displacement area of the throttle device, the area not being involved in control of the volume flow, whereby a minimum obturating section arises in the displacement area.

Abstract: The invention concerns a suction-controlled vane-cell pump whose pumped flow does not increase further above a determined speed but remains practically constant. Radially movable vanes (4), arranged in a rotor (2), form working chambers (12). Between the vanes (4) the rotor (2) has control slots (21) which cooperate with several outlets (22 or 22A) of a front plate (5) located in a pressure zone. The control slots (21) and the outlets (22 or 22A) are dimensioned so that a reflux of oil under pressure can be avoided from a higher-pressure working chamber (12) into a lower-pressure working chamber. The outlets (22 and 22A) are closed by a valve (24) with movable tongues (25, 25A). During the opening stroke, the tongues (25, 25A) rest on a supporting body (26). Suction openings (13 and 13A) communicate with a suction chamber (14) through throttle bores (31, 31A) in order to limit the suction current. Wear due to cavitation can be avoided by the invention.