High-pressure air was injected into the air cavity to prevent the oil from leaking. With the pressure ratio increasing, more air would pass through the clearance between the floating ring seal and the rotor, then enter the oil cavity and escaped from the vent-pipe placed on the wall of ...
. The latter devices are generally rotating labyrinth seals as opposed to stationary labyrinths such as shown inFig. 5.19next to the lip seal. These devices can be very effective in keeping oil from leaking out and dirt or water from leaking in, especially water that is sprayed on a pump ...