Method of assembling a vacuum pump

A vacuum pump, in particular a turbomolecular pump 10, comprises a housing having at least one housing element 12, 14 defining an internal volume with a rotor 16 at least partially therein and supported by at least one bearing 20, 22, 25, 27, 50. The minimum diameter of the internal volume is larger than the maximum diameter of the rotor. The housing element may be a cap element 14 including an interior wall 32. A Holweck stage 29 of the pump may include a cylinder 34 connected to the rotor, with the interior wall arranged within the cylinder. The minimum diameter of the housing element may be provided by the stator 110 of an electromotor 18. An axial magnetic bearing 50 including a radial protrusion 104 may be connected to the rotor, the maximum diameter of the rotor being defined by the radial protrusion. An eddy current damper 100 may include a conductive disk 118 arranged next to at least one damper magnet 120A, 120B connected to the rotor, the disk being connectable to the housing, and the maximum diameter of the rotor being defined by the outer diameter of the disk. The disk may be separated into at least two parts along its circumference.