Hydrodynamic Journal Bearing & Reynolds Wedge

Mechanical Engineering

How It Works

A hydrodynamic journal bearing supports rotating radial loads on a thin film of lubricating oil without solid-to-solid surface contact. When the rotating journal shaft operates with eccentricity (e) relative to the bearing bushing sleeve, the converging wedge geometry drags fluid into a constriction. According to Reynolds lubrication theory, viscous shear develops high hydrodynamic fluid film pressures that levitate the shaft.

Governing Equation
∂/∂x (h³ · ∂p/∂x) = 6 · μ · U · (dh/dx) , h(θ) = c · (1 + ε · cos θ) , W_load = ∫ p · cos θ · dA