Abstract: A security system, which prevents unauthorized access to an adjusting or function element of a fuel supply pump. To that end, the security device comprises a base part, having a bottom by way of which the base part is screwed to a housing wall of the fuel supply pump, and a cap part which is placed, surrounding the function element, on the base part in such a way that the cap part has a side wall that is surrounded with positive complementary engagement by a side wall of the base part. This prevents access to the function element and to the fastening of the base part. The cap part is secured to the base part by connections that are secured against access.

Abstract: The invention relates to a piston, through which a fluid can flow, for a piston pump, which piston has a longitudinal bore into which a spring-loaded inlet valve body is inserted. In order to be able to bring a helical compression spring, which loads the inlet valve body, to bear against an annular shoulder in the longitudinal bore and to be able to check and if necessary improve its seating after installation, the invention proposes to produce the inlet valve body in two parts comprising the inlet valve disk and the inlet valve stem and to join these two parts to one another after the helical compression spring has been correctly inserted into the piston. The inlet valve disk can for example be joined to the inlet valve stem by ultrasonic welding, thermoplastic riveting or screwing.

Abstract: A vane cell pump with a housing ring closed on the face end and with a rotary piston that revolves eccentrically to the inner wall of the housing ring, which rotary piston encloses at least one supply chamber with the inner wall of the housing ring and with at least one spring-loaded vane that is held radially displaceably in order to limit the supply pressure at a given rpm, at least one pressure impingement face that is acted upon by the supply pressure in the supply chamber is formed on the vane in such a way that by the supply pressure, a radial force oriented to the vane counter to the compression spring is produced that at a predetermined supply pressure is greater than the total of the force of the compression spring and the centrifugal force acting on the vane.