Patent Publication Number: US-8534638-B2

Title: Removable gas turbine engine stand

Description:
BACKGROUND 
     The present disclosure relates to an engine stand, and more particularly to a removable engine stand for a gas turbine engine. 
     There are various types of engine stands for use in connection with gas turbine engines. As an example, there are engine stands which include horizontally disposed rings which mount an engine such that the engine longitudinal axis extends generally vertical. Since the engine is effectively vertical, fluids may leak from the engines or be otherwise displaced. 
     In another type of engine stand, a generally horizontally disposed shaft extends through a vertical support member to mount the engine such that the engine longitudinal axis extends generally horizontally. Since the engine is effectively cantilevered, the engine may be subjected to a stress and force moment since the engine center of gravity is displaced from the vertical support. 
     Still another type of engine stand is the engine shipping container itself which may double as a stand. Although effective and tailored to the particular engine, the shipping container may have a relatively large volume and footprint. 
     Yet another type of engine stand is permanently attached to the engine for convenient maintenance operations. Since the engine stand is permanently attached, however, an overall weight increase results. 
     SUMMARY 
     A removable stand assembly for a gas turbine engine according to an exemplary aspect of the present disclosure includes a first stand removably mountable to a gas turbine engine on a first side of a center of gravity of the gas turbine engine and a second stand removably mountable to the gas turbine engine on a second side of the center of gravity of the gas turbine engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various features will become apparent to those skilled in the art from the following detailed description of the disclosed non-limiting embodiment. The drawings that accompany the detailed description can be briefly described as follows: 
         FIG. 1  is a partial phantom view of a rotary-wing aircraft illustrating a power plant system; 
         FIG. 2  is a general perspective view of a gas turbine engine Auxiliary Power Unit (APU) with the removable stand installed mounted within an airframe of the exemplary rotary wing aircraft embodiment with the removable stand installed; 
         FIG. 3  is a general perspective view of the gas turbine engine APU with the removable stand installed partly removed from the exemplary rotary wing aircraft embodiment; 
         FIG. 4  is a general perspective view of the gas turbine engine APU with the removable stand installed; 
         FIG. 5  is an exploded view of a first stand of the removable stand; 
         FIG. 6  is an exploded view of a second stand of the removable stand; 
         FIG. 7  is a side view of the gas turbine engine APU set upon a surface and rested upon the removable stand which straddles the gas turbine APU center of gravity; and 
         FIG. 8  is a side view of the gas turbine engine APU set upon a surface with a crane connected thereto. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  schematically illustrates a rotary-wing aircraft  10  having a main rotor system  12 . The aircraft  10  includes an airframe  14  having an extending tail  16  which mounts an anti-torque system  18 . The main rotor system  12  is driven about an axis of rotation A through a main rotor gearbox (MGB)  20  by a multi-engine powerplant system  22 —here having three engine packages ENG 1 , ENG 2 , ENG 3  as well as an Auxiliary Power Unit (APU)  24 . The engine packages ENG 1 , ENG 2 , ENG 3  and APU  24  are example of gas turbine engines. The multi-engine powerplant system  22  generates the power available for flight operations and couples such power to the main rotor system  12  through the MGB  20 . Although a particular helicopter configuration is illustrated and described in the disclosed embodiment, other configurations and/or machines, such as high speed compound rotary-wing aircraft with supplemental translational thrust systems, coaxial rotor system aircraft, turbo-props, tilt-rotor, fixed wing aircraft and non-aircraft applications such as ground vehicles will also benefit herefrom. 
     The multi-engine powerplant system  22  may require maintenance which requires removal of the engine packages ENG 1 -ENG 3  or the APU  24 . It should be understood that although the present disclosure will be described with reference to the APU  24  within the aircraft  10 , any of the engine packages ENG 1 -ENG 3  as well as other gas turbine engines within a powerplant system may also benefit herefrom. 
     Referring to  FIG. 2 , the APU  24  is mounted to the airframe  14  through attachments  26 . Each attachment  26  is mounted to the APU  24  at respective mounting brackets  28  through removable fasteners  30  such as bolts. The APU  24  may thereby be removed ( FIG. 3 ) with a crane C (illustrated schematically) attached to engine lift points  32  (also illustrated in  FIG. 4 ). It should be understood that various attachments  26  and lift points  32  may alternatively be provided. 
     Referring to  FIG. 4 , the APU  24  also includes engine stand brackets  34 A 1   34 A 2  ( FIG. 5 ),  34 B 1 ,  34 B 2  ( FIG. 6 ), which, as disclosed herein are mounted to an APU gearbox  24 G and a combustor flange  24 F. The engine stand brackets  34 A 1   34 A 2 ,  34 B 1 ,  34 B 2  may be defined at various positions but are generally located on either side of the APU Center of Gravity CG ( FIG. 7 ) opposite the lift points  32  to facilitate placement upon a surface by crane C ( FIG. 8 ). 
     The engine stand brackets  34 A 1   34 A 2 ,  34 B 1 ,  34 B 2  removably receive a respective stand  36 A,  36 B of a removable stand assembly  36  which is readily mounted to the APU  24  while the APU  24  is still mounted to the airframe  14  ( FIG. 2 ). That is, the removable stand assembly  36  is readily attached to the APU  24  even when the APU  24  is in an operationally mounted position within the airframe  14 . Although the removable stand assembly  36  disclosed in the non-limiting embodiment herein includes two stands  36 A,  36 B, it should be understood that only one stand or three or more stands may alternately be provided. 
     Referring to  FIGS. 5 and 6 , each stand  36 A,  36 B includes a support member  38 A,  38 B and a stand bracket  40 A 1   40 A 2 ,  40 B 1 ,  40 B 2  fixed to a distal end of each respective support member  38 A,  38 B. The support member  38 A,  38 B may be tubular, rectilinear, round or other shapes in cross-section and may be manufactured of various materials such as steel alloys, aluminum alloys and others to support the APU  24 . 
     Each stand bracket  40 A 1 ,  40 A 2 ,  40 B 1 ,  40 B 2  is respectively attached to the engine stand brackets  34 A 1   34 A 2 ,  34 B 1 ,  34 B 2  with a quick disconnect pin  44 A 1   44 A 2 ,  44 B 1 ,  44 B 2 . Each quick disconnect pin  44 A 1   44 A 2 ,  44 B 1 ,  44 B 2  may be tethered to the respective stand  36 A,  36 B with a respective tether  46 A 1   46 A 2 ,  46 B 1 ,  46 B 2  or other system to prevent loss thereof. 
     Each stand  36 A,  36 B is positioned on either side of the APU CG and is shaped to support the APU  24  upon a surface after removal from the aircraft ( FIG. 9 ). In one non-limiting embodiment the stands  36 A,  36 B are shaped to maintain the APU  24  in the same attitude as when mounted in the aircraft to, for example, assure the fluids are retained in a desired operational level. 
     In operation, when the APU  24  must be removed and temporarily set down upon a surface, the removable stand assembly  36  is readily installed onto the APU  24 —either while the APU  24  is within the aircraft or after removal therefrom when still attached to the crane C ( FIG. 3 ). The removable stand assembly  36  may also be readily removed prior—or even after installation in the aircraft, hence, the weight of the removable stand assembly  36  is not carried in the design during flight. 
     Although a particular helicopter configuration is utilized to disclose maintenance of the APU  24 , it should be further understood that various vehicles and systems which may require replacement or maintenance thereof such as ground carts, commercial airplanes and helicopters, military airplanes, LCAC landing craft, tanks etc., will also benefit herefrom. 
     It should be understood that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. 
     Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure. 
     The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be understood that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.