Reducer Lubrication
Deterministic engineering intelligence platform for mechanical, structural, and electrical designers. 91 modules validated solvers, 3D CAD workspace, and ISO/DIN standards compliance.
▸Formula · assumptions · example(ISO 14179 (Gearbox thermal capacity) · DIN 51517-3 (CLP Gear oils) · AGMA 9005-E02)
Formula
h_{\min} = 2.65 R' \frac{(G^*)^{0.54} (U^*)^{0.70}}{(W^*)^{0.13}}, \quad Q_{\text{heat}} = P_{\text{in}} (1 - \eta) \le k_{\text{th}} A_{\text{housing}} (T_{\text{oil}} - T_{\text{amb}})
Dowson-Higginson Elastohydrodynamic Lubrication (EHL) minimum film thickness hmin, ISO VG viscosity selection, and thermal equilibrium sump balance.
Assumptions
- · Film thickness parameter Λ = hmin / √(Rq1² + Rq2²) ≥ 2.0 for full fluid film lubrication
- · Operating oil sump temperature maintained ≤ 80 °C to prevent rapid lubricant oxidation
- · Thermal housing dissipation based on ambient air velocity and cooling fin surface area
Worked example
Worked example — Industrial Helical Reducer (Pin = 22 kW, η = 0.96, Housing Area = 1.4 m², Tamb = 25 °C)
Heat generated = 880 W. Natural convection dissipation k_th = 18 W/m²K yields steady-state oil sump temperature Toil = 59.9 °C (well within ISO VG 220 limit).