Patent ID: 7441492

Claim:
Eccentric drive mechanism for a volumetrically acting unidirectional pump including the following features: a) at least one stroke member (HG) which is rotationally fixed to a shaft (W) of a crank mechanism having at least one stroke bearing (HL) eccentric relative to a rotational axis (XX) of the shaft (W); b) the stroke bearing (HL) connecting the stroke member (HG) to a coupling member (KG) which does not participate in a rotary movement and which is in turn connected by a transverse bearing (QL) to at least one pressure member (DG) for a oscillating delivery drive mechanism of at least one piston-cylinder unit of the pump; c) at least one pressure delivery source (DQ) for a fluid lubricant being connected at it's output side to the transverse bearing (QL) via a passage system; d) the passage system, starting from a connection passage (KA) connected to the pressure delivery source (DQ), including at least one first passage (K 1 ) which extends through the stroke member (HG) into the stroke bearing (HL) and at least one second passage (K 2 ) which extends from the stroke bearing (HL) through the coupling member (KG) into the transverse bearing (QL); e) a hollow space arrangement provided in the region of the stroke bearing (HL) within a bearing surface (L 1 ) associated with the stroke member (HG) for the further conduction of the fluid lubricant fluid to the second passage (K 2 ), the hollow space arrangement having, within the bearing surface (L 1 ) and in the peripheral direction of the stroke member (HG), an arrangement which permits a flow of the fluid lubricant between the first passage (K 1 ) and the second passage (K 2 ) in each case only within a low pressure phase of the fluid lubricant in the stroke bearing (HL) and/or in the transverse bearing (QL), f) wherein the hollow space arrangement provided in the bearing surface (L 1 ) of the stroke member (HG) extends over at least a part of a peripheral section (UN) of the stroke member (HG) corresponding to the low pressure phase of the eccentric drive mechanism, has a boundary which extends at least section-wise with a spacing from the boundaries of the bearing surface (L 1 ), and has at least one hollow space in the form of a groove (HKN) extending along a semicircular peripheral section of the stroke member.