Abstract: A pump has a housing which is used as a foundation and comprises a working space for product-feeding units. The bearing axles of the units are arranged in bearing sleeves and introduced into the pump housing from the rear so that the axles extend, via front recesses in the pump housing, into the working space for interaction with the units. Sliding ring seals are arranged at the front recesses in order to seal off the working space from the rear of the pump. The pump housing is provided with a removably fitted front gable in order to permit access to the sliding ring seals from the front end of the pump housing. The pump housing is designed as a seat for the rotationally fixed part of each sliding ring seal and interacts with an element which fixes the axial displacement for the rotationally fixed part. The seat and the rotationally fixed part are arranged for simple introduction into and for removal from the seat of the rotationally fixed part.