Calculating PV for a Plain Bearing

Plain bearings must be evaluated for suitability in an application based on their pressure velocity value or PV value. Plain bearings are rated by their limiting PV, which is a combination of load over a given surface area and the velocity. In order for a plain bearing to be suitable for use without lubrication in an application, the following three parameters need to be met.

Calculate P

P = Maximum pressure or load in pounds per square inch (psi) or kilograms per square centimeter (kg/cm2)
Pressure is over the projected area of load where:

A = Projected Contact Area
L = Bearing Length
d = Shaft diameter
W = Maximum load

PV Figure 1

PV Figure 2

Calculate V

V = Maximum velocity or surface speed in square feet per minute (sfm) or meters per minute (m/min)
Linear velocity = total distance traveled in one minute
Rotational velocity =

PV Figure 3

where n = Rotational speed

Calculate PV

PV = The performance measurement of plain bearings

PV Figure 4