Abstract: A device having a hydraulic drive for civil engineering work has least one shaft that can be rotated by a hydraulic motor. The hydraulic motor is operated by fluid of a hydraulic circuit that is supplied by a hydraulic pump. The hydraulic motor has a changeable displacement, and means for changing the volume stream are provided. A sensor for measuring the fluid pressure is disposed in the hydraulic circuit, and is connected with a control and regulation unit, by way of which the displacement of the hydraulic motor is adjustable, and by way of which the means for a change in the volume stream can be turned on. The control and regulation unit is set up so that in the event of a pressure drop in the hydraulic circuit, a reduction in the displacement of the hydraulic motor as well as a reduction in the volume stream is brought about.

Abstract: A device for a vibrator, including at least one resilient element, with a force/travel curve having a first region, at least approximately given by an equation of formula K=a+b*W, where K is the spring force of the at least one resilient element, W is the spring travel and a and b are number greater than zero and a vibrator including such a device.