Workshop «Shaft alignment and dynamic balancing»
We invite technical specialists to participate in the training course on the topic «Shaft alignment and dynamic balancing» which will take place on 12-13 September, 2019 in Germany (Lubeck). The workshop is arranged for specialists in quality, service engineers, mechanics and power engineers who are responsible for the reliability of machines and industrial equipment.

Kronsforder Allee 45,
23560 Lübeck
Tel: +49 (0) 451-370-87-700
Articles -- Tool kit

Bearing clearance

Bearing clearances ensure normal operation of the bearing and the whole machine. Usually the clearances in rolling element bearings are not considered during calculation of the bearing nominal life but they influence the actual service life significantly.

The bearing clearances are values of movements that appear as a result of movement of one bearing ring relative to another one in case of low measuring load; in radial direction this is a radial clearance Gr, and in axial direction- axial clearance Ga. Both clearance types are typical for all types of radial and radial-thrust bearings. Radial roller bearings have only radial clearances and thrust bearings have only axial clearances. We recommend checking clearances in rolling element bearings using the precision calibration feeler gauges BALTECH FG Series.

There are three types of clearances in rolling element bearings:

- initial or control clearance detected in an assembled bearing during a measuring load (clearances in bearings as received)

-mounting or installation clearances that appear in a bearing after its installation on a shaft or in a housing;

-operating clearances, that appear under load during temperature distribution.

The radial clearance should be monitored using a feeler gauge. The minimum permissible radial clearance in mm according to the requirements of the standards can be approximately defined from the formula: Smin = d/3000,


d- Nominal diameter of the bearing bore, mm

For bearing checking we recommend using the stands for bearing incoming inspection BALTECH MCB-6150 Series.