Adjustable hydrostatic pump

摘要

The adjustable pump designed as a radial piston pump has a cam ring (11) for setting the piston travel. The adjusting force is produced by a servo piston (12) acted upon by a second piston (26) controlled via a hydraulic regulator (24). The adjustable pump conveys a medium which, because of its chemical properties, must not be brought into contact with the pressure medium which is used in the hydraulic regulator (24) and which actuates the piston (26). Thus two different media are present which, in particular, are separated by two sealing rings (39, 40) which bear on the piston (26). In this way, a trouble-free and economical operation of the pump is achieved. Hitherto it had been necessary to use mechanically adjustable pumps for applications like these. <IMAGE>