US Patent 10247105 Air turbine starter with lubrication valve

An air turbine starter includes a transfer tube having a lubrication inlet and a lubrication outlet configured to allow fluid to flow therethrough. A valve is positioned within the transfer tube including a spring. The spring is configured to selectively allow fluid flow within the transfer tube based on fluid pressure differential across the valve. The spring can have three positions: a first position configured to prevent flow within the transfer tube, an intermediate position configured to allow free flow of fluid within the transfer tube, and a compressed positioned to prevent flow to the lubrication outlet.