Oil-cooled carbon seal

#The disclosure relates to gas turbine engines. More particularly, the disclosure relates to cooling of carbon seals in gas turbine engines.

#Carbon seals are commonly used to seal between relatively rotating components in gas turbine engines. In typical situations, the annular carbon seal is spring biased into engagement with an annular seat (typically metallic such as a steel). Often, the carbon seal is on non-rotating static structure and the seat rotates with one of the engine shafts. The sliding engagement causes frictional heating. The heat must be dissipated. With a rotating seat, it is common to use oil cooling. Generally, oil-cooled carbon seals are divided into two categories: “dry face” seals wherein the oil passes through passageways in the seat without encountering the interface between seal face and seat face; and “wet face” seals wherein the oil passes through the seat to the interface so that the oil that flows through the seat cools the seat but then lubricates the interface to further reduce heat generation.

#For both forms of seals, the oil may be delivered through a nozzle and slung radially outward by the rotating component and collected in a radially outwardly closed and inwardly open collection channel from which the passageways extend further radially outward.

#FIG. 1 is a partial partially schematic central axial sectional view of a first seal system.

#FIG. 1A is an enlarged view of a sealing interface area of the seal system of FIG. 1.

#FIG. 2 is a partially schematic central axial sectional view of a gas turbine engine.

#Like reference numbers and designations in the various drawings indicate like elements.

#FIG. 1 shows a seal system 100 having a first member 102 carrying a seal 104. The exemplary seal 104 is a carbon seal having a seal surface or face 106. The exemplary seal 104 is formed as a body of revolution about an axis 500 which is an axis of relative rotation between the first member 102 and a second member 110. FIG. 1 further shows an outward radial direction 502. The exemplary seal face 106 is a radial face. The second member 110 comprises a piece 112 (seat piece) forming a seat for the seal with a seat surface or face 114 in sliding sealing engagement with the seal face 106 at a sealing interface.

#The exemplary illustrated configuration is a dry face configuration. The seal 104 may be biased into axially compressive engagement with the seat face 114 via one or more factors including pressure bias and spring loading. The seal 104 is shown as sealing a space or region 120 inboard of the sealing interface from a space or region 122 outboard. Depending upon configuration, the pressure difference may bias the seal in either direction. FIG. 1 further shows a spring 124 (e.g., a coil spring) providing the required bias. There may be a circumferential array of such springs about the axis 500 each under axial compression.