Piston or plunger pump

A plunger pump, comprising at least one plunger;

• a cylinder part coaxial thereto and accommodating a working chamber for the plunger;
• a cylinder head which has a cylindrical pressure chamber filled with a pump medium and which is coaxially disposed relative to the plunger and is connected to a pressure line;
• a central valve housing which has end faces and is axially positioned between the working chamber of the plunger and the pressure chamber, said valve housing being sealed relative to the cylinder part and also the cylinder head by means of seals and having seats;
• a suction valve and a discharge valve arranged at said end faces on said seats, said valve housing having at least one axial passage controlled by the discharge valve and a suction passage extending from a peripheral surface of the valve housing to a suction valve side end surface thereof and controlled by the suction valve, the central valve housing being inserted through an end face opening formed in an end face of the cylinder head remote from the plunger into the cylinder;
• a base part which closes said opening and secures said valve housing, said valve housing being sealed relative to the cylinder part and the cylinder head by the base part which axially clamps the central valve housing against the cylinder part;
• a piston-like part which has two end faces and is inserted into the pressure chamber and which is acted on at its two end faces by the pressure of the pump medium in the pressure chamber;
• and base part pressing ring seals, which are arranged between the piston-like part and the base part and also the central valve housing in peripheral grooves formed between the respective parts to transmit axial clamping forces radially outwardly against a wall of the pressure chamber while deforming said seals, the piston-like part including a spring housing, said discharge valve including a valve body and a coil spring arrangement which acts on the valve body to close it and is accommodated in said spring housing.

A plunger pump, comprising at least one plunger;

• a cylinder part coaxial thereto and accommodating a working chamber for the plunger;
• a cylinder head which has a cylindrical pressure chamber filled with a pump medium and which is coaxially disposed relative to the plunger and is connected to a pressure line;
• a central valve housing which has end faces and is axially positioned between the working chamber of the plunger and the pressure chamber, said valve housing being sealed relative to the cylinder part and also the cylinder head by means of seals and having seats;
• a suction valve and a discharge valve arranged at said end faces on said seats, said valve housing having at least one axial passage controlled by the discharge valve and a suction passage extending from a peripheral surface of the valve housing to a suction valve side end surface thereof and controlled by the suction valve, the central valve housing being inserted through an end face opening formed in an end face of the cylinder head remote from the plunger into the cylinder head;
• a base part which closes said opening and secures said valve housing, said valve housing being sealed relative to the cylinder part and the cylinder head by the base part which axially clamps the central valve housing against the cylinder part;
• a piston-like part which has two end faces and is inserted into the pressure chamber and which is acted on at its two end faces by the pressure of the pump medium in the pressure chamber;
• and base part pressing ring seals, which are arranged between the piston-like part and the base part and also the central valve housing in peripheral grooves formed between the respective parts to transmit axial clamping forces radially outwardly against a wall of the pressure chamber while deforming said seals, wherein cut-outs are formed in the piston-like part, in the central valve housing and in the cylinder head part and lead to said seals in order to facilitate an exchange of pump medium in annular gaps which are formed on a pressure side of the seals between a peripheral wall of the piston-like part and the cylinder head part on a low pressure side between the peripheral surface of the central valve housing and the cylinder head and the cylinder part.