The invention relates to a pressure generating device (1) for generating a hydraulic pressure as a result of a tensile or compressive load, having connections (3), one of which can be rigidly connected to a frame by means of a mechanism for introducing a mechanical tensile or compressive load, a pressure cylinder (12) and a piston unit (8) extending at least partially and flexibly in the pressure cylinder (12) and bounding a hydraulic chamber (11) filled with hydraulic fluid jointly with the pressure cylinder (12), said chamber being simple and inexpensive in construction, wherein the connections (2, 3) are connected to the pressure cylinder (12) or the piston unit (8) by means of coupling means (4, 7, 14, 17), wherein the coupling means (4, 7, 14, 17) are designed such that the same hydraulic chamber (11) has pressure applied thereto under tensile load and under compressive load.