How to measure bearing clearance?

In some cases, we need to determine the clearance of bearings promptly. This includes measuring the clearance of the bearing unit itself and the clearance of the bearing mounted on a shaft or adapter sleeve. So, how exactly is this measurement performed? First, let's learn about measuring the clearance of a single bearing unit.

When performing this measurement, generally, the bearing to be measured should be placed vertically on a platform. Press down on the outer ring of the bearing by hand, ensuring that the inner and outer rings are not tilted. Rotate the inner ring left and right 1/2 to 1 turn to stabilize the rollers. Stainless steel bearing manufacturers suggest that then any one of the rollers in the left or right row should be positioned directly above the bearing. Use a feeler gauge to measure the internal clearance. During the measurement process, because the outer diameter of the bearing varies, the actual measurement position and point will also differ.

For example, when measuring the clearance of a bearing with an outer ring diameter exceeding 200 mm, the feeler gauge needs to be inserted between the two rows of rollers directly above the bearing and the outer ring, and between the two rows of rollers symmetrically positioned to the left and right of the bearing center and the inner ring, to measure the internal clearance of each bearing. The internal clearance of the bearing is usually represented by the letter R.

The internal clearance measured on the top of the bearing is usually denoted as RT. The internal clearances measured between the two rows of bearing rings and the outer ring are denoted as r1 and r2, respectively. According to the stainless steel bearing manufacturer, the relationship between these elements can be expressed as: RT = 1/2(r1 + r2).

Next, the internal clearance data for the bearing on the left side is measured sequentially. Finally, we can combine these measured data to calculate the internal clearance of the individual bearing unit.