US Patent 10451058 Pump insert

A pump insert without a dedicated housing includes a first pressure plate, a cam ring, a rotor, a second pressure plate, and radially displaceable vanes arranged in slots of the rotor and which run with a vane upper edge thereof engaging a contour of the cam ring during rotation of the rotor. The cam ring includes stagnation point protrusions which are configured as separate, moveable components fastened to the cam ring.