Abstract: A bearing construction having an annular clearance provided between the outer surface of a rotary shaft of a rotatable object and the inner wall of a bearing assembly and a fluid feeding means for filling the clearance with a fluid to form a layer of the fluid. A shaft displacement detecting means detects a displacement of the rotary shaft during a rotating action.

Abstract: A method and apparatus for correcting the unbalance of a rotatable object wherein the apparatus learns from past errors and automatically adjusts to improve future unbalance corrections of the object. The object is rotated a first time and the amount and angular location of unbalance is detected and recorded. The object is than corrected for this measured unbalance and the corrected object is rotated again. The amount and angle of any remaining unbalance is detected. Then the first detected unbalance is combined with the unbalance detected in the corrected object to obtain a correction quantity which can be used when later correcting said object. The invention can be used on objects which have two separate planes of unbalance to correct the unbalance in both planes. The invention can also correct for any errors caused by any inaccuracies in the plane separation process.