The value of the bearing side clearance at the horizontal midplane is half of the top clearance
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The value of the bearing side clearance in the horizontal mid-plane is half of the top clearance. Could you explain in detail why it is half?
During normal measurements, the shaft sinks naturally; as a result, the gap at the bottom is considered to be zero by default. The gap at the top is equal to the sum of the gaps at the top and bottom, while the side gap is half of the top gap – adding these together gives the total gap between the top and bottom.
Consider the shaft and bearing shells as ideal circles. When the shaft is at the bottom, the clearances on both sides of the shaft are equal. In the vertical direction, the inner diameter of the bearing shell equals the top clearance plus the shaft diameter; in the horizontal direction, it equals 2*side clearance plus the shaft diameter. Is it easier to understand now?
You are referring to sliding bearings, which generally have an end clearance and a side clearance. The side clearance is the one on both sides of the shaft, while the end clearance is the gap between the upper bearing shell and the shaft
The inner diameter of the bearing shell should be larger than the outer diameter of the shaft. Under the influence of Earth’s gravity, when the shaft is at rest, its bottom should be in contact with the bottom of the bearing shell, while there should be a certain amount of clearance between the top of the shaft and the top of the bearing shell. When the unit is operating normally, the shaft should be located in the middle of the bearing shell, meaning that the clearance is half of the total clearance.
This statement is not accurate; it depends on the type of bearing and the way it is installed, so it cannot be generalized. If it is a round washer bearing, then such measurement is possible. But with tilting pad or elliptical pad bearings, you can measure to see if the side clearance is half of the top clearance