Bearing selection

Selection of Cooper bearings must take into account both radial and axial loads which are considered independently.

Calculating bearing loads

The prime consideration in calculating bearing loads is the magnitude and direction of the radial bearing load or loads. This radial bearing load is affected by one or more of the following:

Selection for radial load

Selection for radial load is determined independently from the axial load. Determine the radial load, speed and minimum life required. Generally the shaft size has been predetermined. Selection of the bearing can be made using the following formula:

C_r>P x f_n x f_L x f_d
Where C_r = radial dynamic rating
P = calculated effective radial load
f_n = speed (rpm) factor
fl = Life (hours) factor
FD = dynamic or service factor

If high temperatures (above 212°F/100°C) are involved, please refer to notes in Life adjustment factors section.

Selection for axial load

Selection for axial load is considered independently from the radial load. Determine the axial load applied to the bearing. Knowing the speed and desired shaft size, select a bearing using the following formula:

C_a > (FD x f_dn x P_a) / f_b
Where C_a = axial rating
(When P_a > 0.5Ca retaining rings or recessed journal is required see the Shaft tolerance and recess journals section or please consult our technical department)
FD = dynamic or service factor
P_a = calculated axial load
If axial load exceeds 40% of the radial load, please consult our technical department.
f_dn= Velocity (dn) factor
(See scale in Life adjustment factors section)
f_b = 1.0 when dn <2,500”/63,500mm
f_b = 1.25 when dn >2,500”/63,500mm