Patent ID: 9677548
Date: 2017-06-13
CPC Classifications: F04B,F16J

Claim:
1. A pump comprising: at least one piston slidable within an opening along a movement direction in order to vary the volume of a chamber, said chamber comprising an inlet and an outlet for a liquid; a casing within which a driving device is housed for moving said at least one piston along said movement direction; a head within which said chamber is at least partially obtained, said head being fixed to the casing in such a way that said at least one piston delimits a portion of said chamber; and a sealing arrangement arranged along said opening and associated with said at least one piston in a radially external position thereto in order to prevent leaks of liquid from the chamber, said sealing arrangement comprising at least one high pressure sealing element located in a proximal position with respect to the chamber and a low pressure sealing element located in a distal position with respect to the chamber to stop any quantities of liquid that the high pressure sealing element has allowed to pass; wherein said high pressure sealing element is housed inside the head and said low pressure sealing element is housed inside the casing, the pump further comprising a space arranged between said high pressure sealing element and said low pressure sealing element, said space being suitable for placing in communication a suction of the pump and said low pressure sealing element, wherein said space is entirely obtained within the casing and closed by the head.