Roller Forces under Applied Load

One common bearing failure is the plastic deformation due to overloading. This example inspects roller pressures to see if the machinery is overloaded.

The model contains two KOYO roller bearings connected to a shaft. The powerSource applies a load to the middle of the shaft. 

Figure 1 shows the total roller forces for the first roller on left and right bearing, respectively. The roller forces depend on the angular position of the roller and magnitude of the applied load. Since both bearings are identical, they produce the same results.

Figure 1: Roller forces and applied load.

The roller forces, Q, for the first five rollers of the left bearing are shown in Figure 2. All roller forces vary with the same amplitude which is the outcome of the applied load.

Figure 2: DE bearing roller forces. 

Figure 3 shows the contact pressures in the first rollers for the left and right bearing respectively. The allowable contact pressure is around 4000-4600 MPa. Since the contact pressures on the rollers (380-520 MPa) are way smaller than this, the system is not overloaded. On the contrary, it is over-designed. Thus, it would be possible to choose smaller bearings.

Figure 3: Contact pressures.