Rolling rated load bearing clearance is a function of the value of the rated load bearing product samples given, is the value at the time of the effective clearance of zero.
 

Theoretical and experimental proof, the best value is the value of the effective clearance small negative clearance values, this time bearing may have a maximum service life, greater than or less than the optimum value, bearing life will be reduced.

However, the magnitude of reduction in life expectancy in the two directions are different: negative clearance along the direction of reduced very rapidly, causing the temperature rise and expansion of the inner ring and the rolling elements, further increases the clearance of the negative, prone to dramatic life reduce the phenomenon, reduce clearance along the direction of increasing life expectancy is relatively flat much, it is generally clearance values zero clearance for the lower limit, the upper limit in the positive direction of the selected clearance.

Only in precision or important parts in small and stable load and temperature can be precisely calculated and adjusted to ensure that clearance is indeed in the best effective clearance values (small negative clearance), for maximum service life.

Using constant pressure preload method is easier to achieve optimum payload clearance.