Plunger pump

摘要

Hydrostatically driven plunger pump for conveying liquids loaded with abrasive particles. The plunger (14) of the plunger pump is coupled to a double-acting hydraulic piston-cylinder unit (16) which forms the drive and to which hydraulic medium is applied by means of hydraulic control members. Provision is made of devices to which pressure (hydraulic) fluid can be applied and by means of which the plunger-type cylinder (22) and the associated plunger (14) situated in the position in which the working stroke is extended to its maximum can additionally be moved apart relative to one another to such an extent that the plunger is completely withdrawn from the plunger-type cylinder and thus the seal which seals the plunger in the plunger-type cylinder is accessible for exchanging. The devices to which pressure fluid can be applied have for each plunger (14) and plunger-type cylinder (22) at least one, preferably a plurality of cylinder units (58) whose cylinders (56) and whose free piston rod end act, on the one hand, on the assigned plunger-type cylinder (22) and, on the other hand, on a component connected rigidly to the cylinder (42) of the hydraulic piston-cylinder unit (16) driving the respective plunger (14). The working space of the cylinder unit(s) which is active when the piston rod is withdrawn can be connected to a pressure fluid source. <IMAGE>