Optimization on the hydrodynamic groove geometry of rotary seals for automotive transmissions

The feasibility of the cubic spline interpolation function was analyzed which was treated as generic description function of rotating seal used in automotive transmissions with different geometries curve. The method was studied to determine the generic function parameters of groove curve. By using of body-fitted coordinate conversion, the irregular geometries groove in physical domain was converted to regular fan-shaped groove in calculation domain. It could solve lubrication model with irregular groove. On this basis, taking the oil film's highest load carrying capacity as the target, an optimization model of rotating seal groove was established. Also the DOE method was introduced to solve the multi-variable optimization problem. And then the oil film's load carrying capacity and pressure distribution characteristics of optimization groove, spiral groove and linear groove were compared and analyzed. Results show that the cubic spline interpolation function can be the generic description function of rotating seal dynamic pressure groove. The optimum groove with a profile peak in center curve groove geometry possesses higher oil film's load carrying capacity compared with spiral groove and linear groove.