Bearing unit with optimized clamping device

A bearing unit configured to be clamped on a machine shaft, the bearing unit comprising:

• a stationary radially outer ring;
• a radially inner ring comprising a radially inner surface, wherein the radially inner ring is rotatable about an axis of rotation of the bearing unit;
• a row of rolling bodies interposed between the radially outer ring and the radially inner ring;
• a clamping device configured to clamp the bearing unit to the machine shaft, the clamping device comprising:
• a clamping sleeve configured to be radially interposed between the radially inner ring and the machine shaft, the clamping sleeve comprising:
• a threaded flange portion;
• and
• a circumferential slit configured to deform and tighten around the machine shaft;
• a ring nut configured to screw onto the threaded flange portion and exert an axial force on the radially inner ring;
• and
• a disc-shaped elastic element configured to be axially interposed between the ring nut and the radially inner ring;
• wherein the radially inner surface of the radially inner ring is arranged to engage a radially outer surface of the clamping sleeve when the clamping device clamps the bearing unit to the machine shaft;
• wherein a radial length of a contacting portion of the radially inner ring and a radial length of a contacting portion of the elastic element are greater than half of a radial length of an axial surface of the radially inner ring, wherein the contacting portion of the radially inner ring is configured to contact the contacting portion of the elastic element when the clamping device clamps the bearing unit to the machine shaft.