| 摘要 |
A cylinder block (1) has radial bores (3) of rectangular cross section with a piston comprising a hollow roller (5) and a piston cap (4). The rollers (5) are supported on an outer cam (2). The piston caps (4) are periodically exposed to the pressure (p) of a medium which is delivered to them via channels (11, 13) in side sealing plates (6,7) and via the hollow spaces (10) of the rollers (5). The piston caps (4) are provided with sealing strips (17, 18) resting on bore walls (8, 9) and with support ribs (19, 20). Each roller (5), with the two associated bore walls (8, 9), forms gaps each of which, together with the one sealing strip (17, 18) and bore wall (8, 9) define an intermediate chamber (pc, po). From the intermediate chambers (pc, po) channels (25, 26) lead in the piston cap (4) to the support faces ( 23, 24) of the support ribs (19, 20). The support face (23) lifting away during operation at a predetermined inclination of the cam (2) places the intermediate chamber with which it communicates under an intermediate pressure (pc) determined by the pertinent gap (hc) of the roller (5) and the bore wall (8), this intermediate pressure (pc) forcing a speed upon the cylinder block (1). The oppositely located intermediate chamber having low pressure (po) is sealed off from the pressure (p) of the medium by the support face (24) of the other support rib (20) resting on the other bore wall (9). As a result, it is possible to reduce unavoidable leakage losses without impairing the mechanical efficiency of the unit. |
