Pump assembly

A pump assembly comprising:

• an electric drive motor comprising at least a motor drive shaft and a rotor, wherein the motor drive shaft extends along a rotor axis and the rotor is mechanically coupled to the motor drive shaft;
• and
• a pump housing enclosing an impeller that is mechanically coupled to a pump drive shaft, wherein the pump drive shaft extends along the rotor axis,
• wherein the motor drive shaft is releasably coupled to the pump drive shaft by a drive shaft coupling for transferring torque from the motor drive shaft to the pump drive shaft, wherein the motor drive shaft being hollow from a first axial motor drive shaft end to a second axial motor drive shaft end, wherein the pump drive shaft protrudes into the hollow motor drive shaft at the first axial motor drive shaft end, wherein the drive shaft coupling is arranged at least partly within the hollow motor drive shaft for transferring torque from the motor drive shaft to the pump drive shaft by frictional connection with a radial inner surface of the hollow motor drive shaft and/or a radial outer surface of the pump drive shaft, wherein the drive shaft coupling is accessible by an elongate tool through the second axial hollow motor drive shaft drive end for selectively tightening and releasing the drive shaft coupling.