Rotary piston pump, method for fixing rotary pistons of a rotary piston pump and method for dismantling rotary pistons of a rotary piston pump

A method for fixing at least two counter-rotating rotary pistons to respectively assigned drive shafts in a pump space of a rotary piston pump, the method comprising:

• pushing the rotary pistons onto free end regions of the respective drive shafts arranged in the pump space;
• aligning the rotary pistons on the respective drive shafts;
• widening the end regions of the drive shafts to produce a frictional connection between a seating of the rotary piston and the end region of the respective drive shaft for fixing the rotary piston.

A method for dismantling at least two counter-rotating rotary pistons of a rotary piston pump, the rotary pistons being arranged in a pump space on drive shafts, wherein each rotary piston includes a seating and wherein each drive shaft has an end region that is arranged and fixed in the seating of the respective rotary piston, wherein an outer diameter of each drive shaft in the end region is configured to be widened elastically, and wherein in an operational state, in which the rotary pistons are arranged on the respective drive shafts, a frictional connection or a frictional and form-fit connection is formed between the respective seating of the rotary piston and the end region of the respective drive shaft in response to the diameter of the respective drive shaft being widened, so that a power transmission takes place in a play-free manner, the method comprising:

• releasing the frictional connection between the seating of the rotary piston and the end region of the drive shaft by reducing the outer diameter of the end region of the drive shaft
• removing the rotary piston from the respective drive shaft.