74 have been joined together at the end sides a groove shaped recess in the form of the mutually mated chamfers is created on the internal sleeve face the main body 77 at least between the annular seals 80 81 is adapted to the mutually mated hydraulic lines 73 74 on account thereof said main body 77 is caused to completely bear on the hydraulic lines 73 74 between the annular seals 80 81 on account of which damage is avoided during widening a gap is provided between the respective end side of the main body 77 and the respective base of the end side bores 75 76 a hydraulic medium thus flows up to the outer side of the respective annular seal 80 81 the effective face for the pressure differential which is formed is thus the sleeve face of the main body 77 between the annular seals 80 81 fig4 in an exemplary manner shows the most important components of an exemplary hydraulic system 88 the hydraulic system 88 comprises a hydraulic source 90 from which a hydraulic line 92 branches off and as a hydraulic sink a power switch drive 98 from which in turn a hydraulic line 94 branches off the two hydraulic lines 92 94 are interconnected by way of a hydraulic connection 96 according to the invention all commercially available annular seals which are resistant to the high operational.