A LUBRICATION DESIGN APPLICATION OF SPIRAL GROOVE LIQUID SEAL TO THE CARRIER OF VANE-TYPE LPG FUEL PUMP

In this study, to improve fundamentally a poor lubrication performance of critical component carrier at its suction face in a rotary vane-type external fuel pump for LPLi vehicles, a spiral groove seal design has been adopted, which can be applied at such a very low viscosity of liquid LPG. Utilizing the Galerkin finite element method a lubrication characteristic analysis of the seal has been carried out in detail, and its lubrication performance optimization has been performed by systematic parameter analyses of design variables. Compared to a starting reference design, a final optimized spiral groove seal design has shown the result of increasing a groove depth by 66.7% while increasing an equilibrium seal clearance by 65.3%. It has been predicted that at the equilibrium condition the optimally designed carrier spiral groove liquid seal is capable of maintaining a stable lubricating film with an axial stiffness of 3.376x10(7) N/m and operating in noncontact and in addition leakage through the seal is very minimal.