A simple calculation method of the wear rate of mechanical seal end faces

The end face materials of mechanical seals are usually in the form of soft-hard pair. For a properly designed and used mechanical seal, the wear form of softer end face is mainly adhesive wear. During operation, the contact between the end faces of the mechanical seal occurs on the higher asperities on the end faces of the softer sealing ring.During friction, the contact point deforms to produce adhesion, and then the adhesion joint is sheared by friction during sliding. This alternating process of adhesion, destruction, and re-adhesion constitutes adhesive wear.

There are many methods for calculating adhesive wear, but most of them are based on Archard's theoretical model of wear. Gu Yongquan gave a simple calculation method for the wear rate of mechanical seal face based on Archard wear theory, and its expression is:

in which γ——wear rate of mechanical seal end face, m
Kw——wear coefficient, indicating the probability of wear debris generated at the adhesive joint, which is related to the friction pair material and working conditions
H2——Brinell hardness of soft ring material, Pa
pc——specific pressure of sealing end face, Pa
v——the average linear velocity of the sealing end face, m/s, v = πrmn /30
rm——the average radius of the sealing end face, m
n ——speed, r/min

The wear coefficient Kw in the formula (1) (see the first picture below ) is a similarity coefficient, which is a probability coefficient. For example, Kw = 10 -6, that is, every 1,000,000 contacts of the surface contact joints will produce a wear, which reflects the comprehensive influence of the friction state, sliding speed, temperature, interface reaction and material properties of the end faces of the friction pair of the mechanical seal, and is a function of the tribological system.The smaller the value of the wear coefficient Kw, the less the wear, which is often measured by the wear test.