A radial slide bearing’s clearence constitutes the difference between the bearing’s internal diameter and the shaft’s diameter. During hydrodynamic operating conditions, the clearence is directlydecisive for the forming of the oil film. It is the function of the oil film to separate the shaft and the bearing surface from each other, so that metal contact is avoided.

Another purpose of the clearence is to accommodate changes in geometry, which can be theconsequence of an increased or reduced temperature in the surroundings. It is not so unusualthat the shaft expands more than the bearing during increases in temperature. The causes reduced clearence.

Generally, for high loaded, slowlymoving bearings a small clearenceis chosen. For bearings that have light loads and move rapidly alarger clearence is chosen. From experience, 0.3-5% of the shaftdiameter is recommended. See thefigure below for the dependence of the bearing clearence of the slidingvelocity.

According to previous reasoning, the clearence is dependent on both the load and the sliding velocity.Other parameters that affect the play are, Bearing load
for example, the type of lubricant and the operating temperature. The figures below illustratethe bearing clearence dependence on the loading. At the same time,the sliding velocity is affected.