Reciprocating piston pump for conveying and dosing aqueous solutions in exhaust gas cleaning system of vehicle, has spring area sealed against working fluid by piston and spring bearing, where area is filled with compressed gas

摘要

The pump (1) has an electromagnet (2), and displacement body areas (3, 4) separated by a hollow piston rod (5). The rod has a non-return valve (6) that comprises a valve spring (8). The rod is moved in a slide bearing (19) in a dynamically sealing manner, and comprises a movable piston (9). The piston is pressurized by a spring (10) i.e. spiral spring. A spring area (11) is not filled with working fluid and sealed against the working fluid by the piston and a spring bearing (14) i.e. ball. The spring is made from elastomer material, and the spring area is filled with compressed gas. An independent claim is also included for a method for operating a reciprocating piston pump.