US Patent 7534101 Pump with radial packing ring

A pump, preferably a vane cell pump for supplying a transmission with oil, includes a pump housing and a rotating group which is disposed inside the pump housing. The rotating group includes a side plate that may be mounted inside the pump housing in such a manner as to produce, at least temporarily, an axial gap between the side plate and the pump housing. A shaft is mounted inside the pump housing and a radial packing ring is located in a recess around the shaft. The packing ring seals off the rotating group towards the exterior radially on the pump housing and radially on the shaft using a sealing lip.