Kraaglagers

Collar bearings are a type of bearing used in machines to support axial loads on rotating shafts, it can have single or multiple collars.

Consider a single collar bearing subjected to an axial load. The area between the external and the internal radius of the collar is the total bearing contact area.

Assuming even support for the bearing, the uniform normal pressure can be expressed as the ratio of force over the bearing area.

Consider an infinitesimal area element on the bearing. The force acting on the differential area can be expressed as a product of the friction coefficient, pressure, and the differential area.

The moment required to cause impending rotation of the shaft is determined from the moment equilibrium equation about the rotational axis.

Next, integration is used to determine the applied moment needed to overcome all the frictional forces.

Finally, by substituting the values of differential force and differential area and integrating the equation over the total bearing area, the moment of the shaft can be estimated.