Stribeck-Hersey curve

Liquid lubrication mechanism. There are four defined regimes of liquid lubrication hydrodynamic (thickness of lubricant film (h), h > 0.25 pm), elastohydrodynamic (h 0.025 to 2.5 pm), boundary (h 0.0025 pm), and mixed. These regimes are dependent on oil viscosity (Z) and relative velocity (V) and are inversely proportional to the load (L), (ZV/L). Fig. 5.1, known as the Stribeck-Hersey curve, depicts these regimes in terms of friction coefficient versus viscosity, velocity, and load (ZV/L) (Fusaro, 1995). 

Fig. 5.1. Stribeck-Hersey curve coefficient of friction (f or p) as function of viscosity (Z) velocity (V) / load parameter (L) h = thickness of lubricant film (Fusaro, 1995)...

Lubrication mechanism How do you expect each of the following regimes to change in going from thickness of lubricating film h to a coefficient of friction, p in the Stribeck-Hersey curve Fig.5.1 There are three defined regimes of liquid lubrication (a) hydrodynamic, h 25 pm, (b) elastohydrodynamic, h = 0.025 to... 

The Stribeck curve explains the relationship between the coefficient of friction and the lubrication thickness with a certain constant called Hersey number. Hersey number is the multiplication of the viscosity of the lubricant and the velocity of the moving object divided by the pressure applied on the object. 

---