US Patent 8186937 Vacuum pump

A turbomolecular vacuum pump (54) comprises a housing (70) and a rotor (52) supported by a bearing arrangement (64) for rotation relative to the housing (70). The bearing arrangement (64) comprises a bearing (72, 74, 76, 78) supported in both radial and axial directions by a resilient support (80) comprising inner (86) and outer (88) annular portions connected by a plurality of flexible members (84), the resilient support (80) having a radial stiffness in the range from 50 to 500 N/mm.