Main bearings supporting a gas turbine rotor at opposite ends of the turbine are prone to oil leakage, particularly at low speed on start-up and shut-down. These bearings are typically enclosed in split bearing housings which incorporate annular split bearing seals both fore and aft of the bearing itself. Large volumes of oil are fed to the bearings on start-up and during normal operation. Extraction air is used to pressurize the seals at operating speed and is effective to prevent oil leaks, but this air is not available during start-up and shut-down.
It has been attempted to solve the oil leak problem by forming grooves on opposite sides of one of the bearing housing half sections. These grooves were intended to more or less enclose the bearing itself and to prevent oil from creeping from the bearing through the horizontal joint along the mating surfaces of the housing half sections. Units tested after this modification nevertheless still exhibited oil leaks. It is a principal objective of this invention, therefore, to prevent oil leaks in gas turbine bearings and to prevent resulting costly tear-downs and shipment delays.