<p>The device has a gearbox well (1) with several spur gears (4) connected to rotor shafts (5) so as to rotate with them. The individual spur gears are adjacent to each other and engaged with each other. The device has a supporting sleeve arranged in the gearbox well and a housing sleeve arranged in the supporting sleeve and protruding through it so that the supporting sleeve encloses the housing sleeve over 360 degrees.</p>
