Abstract: A lubrication system for supplying lubricants between two environments is provided. The first environment is disposed within a first housing and the second environment is disposed within a second housing having a supply opening and an exhaust opening. The system includes a lubricant supply tube disposed within the supply opening and configured to supply lubricant from the first environment to the second environment. The system also includes a receptacle disposed within the second housing and configured to receive lubricant supplied from the supply tube and to hold a predetermined volume of the lubricant. A check valve is disposed within the second housing and is in fluid communication with the exhaust opening. The check valve is configured to receive overflow lubricant from the receptacle, if the lubricant exceeds the predetermined volume and to provide a seal between the first and second environments in response to a pressure differential therebetween.

Abstract: A shroud is provided for separating an air turbine starter housing from a turbine wheel. The shroud comprises a ring and a bumper. The ring is configured to be disposed between the turbine wheel and the housing and has an outer peripheral surface and an inner peripheral surface that defines a flow channel. The bumper is coupled to and extends radially inwardly from the ring inner peripheral surface and defines a bumper section of the ring flow channel. At least a portion of the bumper section has a cross-sectional flow area that is less than another cross sectional flow area of the ring flow channel.