To provide a high pressure hydraulic system in a single housing.

This hydraulic system suitable for use in, in particular, a work machine is provided with a hydraulic source. A hydraulic converter has an inlet connected with a pressure source and an outlet. At least one hydraulic motor has an inlet. The hydraulic converter and each hydraulic motor are arranged in the housing. The housing specifies at least one fluid conduit connecting the inlet of at least one hydraulic motor and the outlet of the hydraulic converter and/or the pressure source mutually by fluid. Since the housing specifies the fluid conduit connecting various constituent parts mutually therein, a hydraulic pressure may be increased more than an ordinary operation pressure.