Device and method for discharging sealing air in a turbofan engine

Abstract

A device and method for discharging sealing air in a turbofan engine includes a primary flow duct that extends through a core engine of the turbofan engine and a bypass duct. The device has at least one bearing chamber sealed by sealing air of the turbofan engine, said bearing chamber surrounding at least one oil-lubricated bearing element for mounting a mechanical component of the turbofan engine. At least one discharge path for escaping sealing air is provided, which extends up to the bypass duct of the turbofan engine.

1 . A device for discharging sealing air in a turbofan engine comprising a primary flow duct that extends through a core engine of the turbofan engine and a bypass duct, where the device has at least one bearing chamber sealed by sealing air of the turbofan engine, said bearing chamber surrounding at least one oil-lubricated bearing element for mounting a mechanical component of the turbofan engine,
 wherein at least one discharge path for escaping sealing air that extends up to the bypass duct of the turbofan engine.   
     
     
         2 . The device in accordance with  claim 1 , wherein the discharge path extends through at least one stator wheel of the primary flow duct. 
     
     
         3 . The device in accordance with  claim 2 , wherein the stator wheel has at least one cavity for providing an air passage for the sealing air. 
     
     
         4 . The device in accordance with  claim 1 , wherein the discharge path is formed, at least in some sections, by casing and/or wall elements that provide an air passage for the sealing air. 
     
     
         5 . The device in accordance with  claim 1 , wherein the discharge path has at least one seal to a rotating element of the engine. 
     
     
         6 . The device in accordance with  claim 5 , wherein the discharge path has at least one seal to a fan or a rotor of the engine so that a gap is substantially closed by said seal between a casing delimiting the discharge path in this area and the fan or rotor. 
     
     
         7 . The device in accordance with  claim 1 , wherein the bearing chamber is provided with bearing elements for mounting an engine shaft. 
     
     
         8 . The device in accordance with  claim 1 , wherein the bearing chamber is arranged in front of the tapping point for the sealing air relative to the axial direction of the engine. 
     
     
         9 . The device in accordance with  claim 1 , wherein the discharge path is designed such that it ends in the bypass duct in front of or behind a fan stator wheel arranged in said bypass duct. 
     
     
         10 . The device in accordance with  claim 1 , wherein the device includes an axially front bearing chamber area and an axially rear bearing chamber area of one or different bearing chambers, where a discharge path section starts from each of the bearing chamber areas, and the discharge path sections combine to form the discharge path. 
     
     
         11 . The device in accordance with  claim 10 , wherein the discharge path extends through at least one stator wheel of the primary flow duct and the combination of the discharge path sections takes place before the discharge path extends through a stator wheel of the primary flow duct. 
     
     
         12 . The device in accordance with  claim 1 , wherein a sealing air seal is associated with the bearing chamber sealed by sealing air, said sealing air seal providing a defined sealing pressure around the bearing chamber, where excess sealing air—possibly contaminated with oil that has leaked from the bearing chamber—escapes via the sealing air seal and is discharged via the discharge path to the bypass duct. 
     
     
         13 . A turbofan engine provided with a primary flow duct extending through a core engine of the turbofan engine, a bypass duct and a device having the features of  claim 1 , where the discharge path ends in the bypass duct and is designed to guide escaping sealing air into the bypass duct. 
     
     
         14 . A method for discharging sealing air in a turbofan engine comprising a primary flow duct that extends through a core engine of the turbofan engine, and a bypass duct, which method has the following process steps:
 supplying sealing air to a bearing chamber of the turbofan engine that has at least one oil-lubricated bearing element, and   discharging of escaping sealing air, which can be contaminated with oil exiting the bearing chamber, to a bypass duct of the turbofan engine.   
     
     
         15 . The method in accordance with  claim 14 , wherein oil-contaminated sealing air exiting a sealing air seal is discharged into the bypass duct.