Pump assembly with hydrodynamic sliding bearings, for use in high pressure liquid chromatography

摘要

The pump assembly has a hydrodynamic radial sliding bearing with a movable shaft (10) rotatably carried in a stationary load bearing assembly (20) formed by two bearing blocks and with ball bearings and driven by a flexible shaft. A variable spring force (F) is exerted on the bearing using a lever with the bearing force being displayed on a scale. An outlet (40) is provided by a small delivery hole at the bearing surface with a connection for a hydraulic capillary at the location of the expected maximum pressure. The fluid enters through an inlet (30) and the sliding space within the pump case (300). A flow sensor produces a flow signal which is supplied to a comparator, which provides a control signal to an adjustable loading unit, to provide a pump flow according to the flow signal.