LUBRICATION CIRCUIT OF MACHINES WITH CRANK MECHANISM

The subject of the invention is a lubrication circuit for machines with crank drive, especially plunger and piston pumps in which in a crankcase (1) at least one crosshead (3) provided with a crosshead journal (31) and a connecting rod (5) is supported so that it can slide in a crosshead guide (101). The connecting rod (5) is coupled by way of a connecting rod bearing (51) to the crankshaft (4) supported in main bearings (41) in the crankcase (1). In the crankcase (1) a single through lubrication duct (6) running perpendicular to the longitudinal axis of the crosshead guide (101) is formed in the middle area of the crosshead stroke. Perpendicular to the axis of the said duct, feed lubrication ducts (61) to the main bearings (41) are formed in the crosshead guide (101) of the crankcase (1), connecting rod lubrication ducts (62) in the connecting rod (5) and journal lubricating ducts (63) in the crosshead journal (31). The main lubricating duct (6) is so designed that the ratio L < d + D and at the same time one of the ratios d = D > 0.5 L, d > D > 0.25 L applies to its diameter (D) compared to the diameter (d) of the hollow chamber (311) of the crosshead journal (31) and the stroke length (L) of the crosshead journal (3).