Driving device for a centrifugal separator

A driving device for a centrifugal separator, the centrifugal separator including:

• a centrifugal rotor rotatable about a substantially vertical rotational axis (R);
• a spindle that supports at one end thereof the centrifugal rotor;
• a frame, rotatably supporting the spindle during normal operation of the centrifugal rotor by means of a first bearing and a second bearing, said first bearing being arranged between the centrifugal rotor and said second bearing;
• said driving device comprising an electric motor arranged to drive the spindle and having a stator non-rotatably connected to the frame, and a rotor supported by the spindle between the two bearings;
• a spring device arranged to permit but counteract by spring force, in an area axially between the centrifugal rotor and the electric motor, radial movement of the first bearing relative to the frame;
• a bearing support member supported by the frame and arranged to prevent substantial radial movement of said second bearing;
• and wherein
• the stator of the motor is fixed to the frame and is immovable relative thereto, the rotor of the motor being radially movable relative to the stator together with the spindle, a gap between the rotor and the stator of the motor being dimensioned to permit the radial movement of the rotor of the motor.