US Patent 11047249 Labyrinth seal with passive check valve

A gas turbine engine component includes a static component with at least one first flow channel. The labyrinth seal rotates relative to the static component. The labyrinth seal is spaced from the static component by a second flow channel. The flow passing between the labyrinth seal and the static component will have a first portion that travels through the at least one first flow channel and a second portion that travels through the second flow channel with the first portion of the flow being reintroduced into the second flow channel to create a flow restriction.