Engine component stack and assembly thereof

Aspects of the disclosure are directed to components of an engine and one or more methods for assembling the components. A first component is positioned adjacent to a second component such that a first surface of the first component abuts the second component. A cooling plate is coupled to the first component such that a first surface of the cooling plate abuts a second surface of the first component. A loading ram is coupled to the cooling plate such that a second surface of the cooling plate abuts the loading ram.

BACKGROUND

Gas turbine engines, such as those which power aircraft and industrial equipment, employ a compressor to compress air that is drawn into the engine and a turbine to capture energy associated with the combustion of a fuel-air mixture. Bearings are used to support the rotational hardware of an engine. For example, bearings are used to support a shaft of the engine.

During assembly of an engine, bearing compartment components typically have an interference fit with a shaft. In order to facilitate installation of the bearing, the bearing is heated to at least a threshold temperature that causes the bearing to grow larger than (a diameter of) the shaft so that the bearing can slide over the shaft and into a designated position. This process is repeated for other components that have an interference fit; examples of such other components include seals, spacers, oil scoops, etc.FIG. 2illustrates a system200that includes a seal206, a first bearing212a, a spacer218, and a second bearing212barranged relative to (e.g., radially outward from) a shaft224. The first bearing212aincludes a first roller/rolling element213aand a first race214aand the second bearing212bincludes a second roller/rolling element213band a second race214b.

During assembly, the components206-218are installed on the shaft224in the order just mentioned (e.g., left-to-right inFIG. 2). For example, the seal206is installed first, then the first bearing212a, then the spacer218, then the second bearing212b. The arrangement/positioning of components (e.g., the components206-218) adjacent to one another about a shaft (e.g., the shaft224) may be referred to as a “stack” herein.

During assembly, each of the components206-218is heated as described above and then, in turn, pressed against the prior component in the stack (e.g., the component that is to the left inFIG. 2) via engagement of a loading ram240. Regarding the first/left-most component in the stack (e.g., the seal206inFIG. 2), that component may be pressed against a lip/shoulder224aof the shaft224via the loading ram240. In this respect, the shoulder224amay form a part of the stack. The loading ram240is frequently implemented as a hydraulically actuated member.

While the loading ram240is engaged/applied to the component being added/assembled to the stack, the component (e.g., the second bearing212bas shown in the example ofFIG. 2) that the loading ram240interfaces to is allowed to cool to a threshold temperature. Once this threshold temperature is reached, the loading ram240is disengaged/removed from the stack. Maintaining the loading ram240in an engaged state during component cooling ensures that the component (e.g., the second bearing212binFIG. 2) remains properly seated and gaps do not form between components in the stack.

Allowing each of the components in the stack to cool represents a cost in terms of the time it takes to assemble the engine. In some instances a component may take on the order of one hour to cool to the threshold temperature. In order to mitigate/reduce this time/cost, air may be blown onto a component to accelerate the rate at which the component cools. The use of blown air may have a tendency to introduce debris to the component. As such, the practice of using blown air may not be acceptable. This is particularly true in the context of the bearings212aand212b, due to the high cleanliness standards that are frequently associated therewith.

BRIEF SUMMARY

Aspects of the disclosure are directed to a method for assembling components of an engine, comprising: positioning a first component adjacent to a second component such that a first surface of the first component abuts the second component, coupling a cooling plate to the first component such that a first surface of the cooling plate abuts a second surface of the first component, and coupling a loading ram to the cooling plate such that a second surface of the cooling plate abuts the loading ram. In some embodiments, the method further comprises engaging the loading ram subsequent to coupling the loading ram to the cooling plate. In some embodiments, the method further comprises engaging a cooling system subsequent to engaging the loading ram, where the cooling system includes the cooling plate. In some embodiments; the cooling system includes a fluid source coupled to the cooling plate, and the cooling plate includes an input port, an output port, and a passage disposed between the input port and the output port, and the method further comprises receiving, by the input port, a fluid from the fluid source, and conveying, via the passage, the fluid from the input port to the output port. In some embodiments, the fluid includes compressed air. In some embodiments, the cooling system includes a fluid source and a nozzle, and the method further comprises receiving, by the nozzle, a first fluid from the fluid source, and transmitting, by the nozzle, a second fluid to the cooling plate. In some embodiments, the nozzle includes a vortex tube with an input port and an output port, and the method further comprises receiving, by the input port, the first fluid from the fluid source, and transmitting, by the output port, the second fluid to the cooling plate. In some embodiments, the first fluid has a first temperature and the second fluid has a second temperature that is less than the first temperature. In some embodiments, the method further comprises heating the first component prior to positioning the first component adjacent to the second component. In some embodiments, the method further comprises determining that a temperature of the first component is less than a threshold subsequent to coupling the cooling plate to the first component, and decoupling the cooling plate from the first component based on determining that the temperature of the first component is less than the threshold. In some embodiments, the threshold is approximately equal to a temperature of a room where the first component is located. In some embodiments, the method further comprises disengaging a cooling system based on determining that the temperature of the first component is less than the threshold, where the cooling system includes the cooling plate. In some embodiments, the method further comprises measuring the temperature of the first component to determine that the temperature of the first component is less than the threshold. In some embodiments, the method further comprises decoupling the loading ram from the cooling plate subsequent to coupling the loading ram to the cooling plate, and decoupling the cooling plate from the first component subsequent to decoupling the loading ram from the cooling plate. In some embodiments, the method further comprises subsequent to decoupling the cooling plate from the first component, positioning a third component adjacent to the first component such that a first surface of the third component abuts the second surface of the first component, subsequent to positioning the third component adjacent to the first component, coupling the cooling plate to the third component such that the first surface of the cooling plate abuts a second surface of the third component, and subsequent to coupling the cooling plate to the third component, coupling the loading ram to the cooling plate such that the second surface of the cooling plate abuts the loading ram. In some embodiments, the first component is a bearing that includes a roller and a race, and the method further comprises abutting the race to a shaft of the engine, where the second surface of the first component is a surface of the race. In some embodiments, the second component is one of a seal, a spacer, or a shoulder of a shaft of the engine, and where the loading ram is hydraulically actuated. In some embodiments, the method further comprises subsequent to coupling the cooling plate to the first component, applying a cooling fluid directly to the first component.

Aspects of the disclosure are directed to a system comprising: a first component, a second component positioned adjacent to the first component such that a first surface of the second component abuts the first component, a cooling plate positioned adjacent to the second component such that a first surface of the cooling plate abuts a second surface of the second component, and a loading ram coupled to a second surface of the cooling plate.

Aspects of the disclosure are directed to a bearing stacking device, comprising: a housing configured to surround a shaft, where the housing includes a first surface and a second surface, where the first surface is configured to abut a component disposed on the shaft, a thermal transfer apparatus configured to transfer thermal energy to or from the component, and a loading ram configured to position the first surface of the housing in axial relation to the component.

DETAILED DESCRIPTION

It is noted that various connections are set forth between elements in the following description and in the drawings (the contents of which are incorporated in this specification by way of reference). It is noted that these connections are general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities or a space/gap between the entities that are being coupled to one another.

Aspects of the disclosure may be applied in connection with a gas turbine engine.FIG. 1is a side cutaway illustration of a geared turbine engine10. This turbine engine10extends along an axial centerline12between an upstream airflow inlet14and a downstream airflow exhaust16. The turbine engine10includes a fan section18, a compressor section19, a combustor section20and a turbine section21. The compressor section19includes a low pressure compressor (LPC) section19A and a high pressure compressor (HPC) section19B. The turbine section21includes a high pressure turbine (HPT) section21A and a low pressure turbine (LPT) section21B.

The engine sections18-21are arranged sequentially along the centerline12within an engine housing22. Each of the engine sections18-19B,21A and21B includes a respective rotor24-28. Each of these rotors24-28includes a plurality of rotor blades arranged circumferentially around and connected to one or more respective rotor disks. The rotor blades, for example, may be formed integral with or mechanically fastened, welded, brazed, adhered and/or otherwise attached to the respective rotor disk(s).

The fan rotor24is connected to a gear train30, for example, through a fan shaft32. The gear train30and the LPC rotor25are connected to and driven by the LPT rotor28through a low speed shaft33. The HPC rotor26is connected to and driven by the HPT rotor27through a high speed shaft34. The shafts32-34are rotatably supported by a plurality of bearings36; e.g., rolling element and/or thrust bearings. Each of these bearings36is connected to the engine housing22by at least one stationary structure such as, for example, an annular support strut.

As one skilled in the art would appreciate, in some embodiments a fan drive gear system (FDGS), which may be incorporated as part of the gear train30, may be used to separate the rotation of the fan rotor24from the rotation of the rotor25of the low pressure compressor section19A and the rotor28of the low pressure turbine section21B. For example, such an FDGS may allow the fan rotor24to rotate at a different (e.g., slower) speed relative to the rotors25and28.

During operation, air enters the turbine engine10through the airflow inlet14, and is directed through the fan section18and into a core gas path38and a bypass gas path40. The air within the core gas path38may be referred to as “core air”. The air within the bypass gas path40may be referred to as “bypass air”. The core air is directed through the engine sections19-21, and exits the turbine engine10through the airflow exhaust16to provide forward engine thrust. Within the combustor section20, fuel is injected into a combustion chamber42and mixed with compressed core air. This fuel-core air mixture is ignited to power the turbine engine10. The bypass air is directed through the bypass gas path40and out of the turbine engine10through a bypass nozzle44to provide additional forward engine thrust. This additional forward engine thrust may account for a majority (e.g., more than 70 percent) of total engine thrust. Alternatively, at least some of the bypass air may be directed out of the turbine engine10through a thrust reverser to provide reverse engine thrust.

FIG. 1represents one possible configuration for an engine10. Aspects of the disclosure may be applied in connection with other environments, including additional configurations for gas turbine engines. Aspects of the disclosure may be applied in connection with non-geared engines.

Referring toFIG. 3, a system300is shown. The system300may be associated with a bearing compartment of an engine. For example, the bearings212aand212bmay correspond to the bearings36of the engine10described above.

The system300may include a plate320that may be used during assembly of the system300. For example, inFIG. 3the plate320is shown as being disposed between the loading ram240and a component (illustratively, the second bearing212b) that is being assembled into a stack. The plate320may function as a heat sink by withdrawing heat from the component that is being assembled into the stack. In this respect, the plate320may be referred to as a cooling plate. While the loading ram240is shown separately from the plate320, in some embodiments the loading ram240may be integrated with the plate320.

The plate320may be made of one or more materials. For example, in some embodiments steel may be used. Steel may provide sufficient strength relative to the loads that may be encountered during assembly from, e.g., the loading ram240, as described further below while still providing a high degree of thermal conductivity. In embodiments where load tolerances are not as much of a consideration, aluminum may be used to enhance thermal conduction (relative to steel). In some embodiments, one or more metal alloys may be used in conjunction with the plate320.

Referring briefly toFIG. 4, an illustrative embodiment of a cooling system400incorporating the plate320ofFIG. 3is shown. The plate320may include one or more channels/passages420that may be used to convey a fluid. The fluid may be introduced to the plate320from a source426at one or more input ports (e.g., port434). The fluid may be exhausted from the plate320via one or more output ports (e.g., port440).

In some embodiments, the fluid that exits the output port440may be exhausted to an external, ambient environment. In some embodiments, the fluid that exits the output port440may be returned to the source426(as reflected by the dashed line emanating from the output port440towards the source426inFIG. 4) in order to form a closed-loop circuit. Stated slightly differently, the fluid may be recycled/reused in some embodiments. The fluid may be conditioned/processed prior to reuse.

The fluid that is provided by the source426may include air, such as for example compressed air that is typically found in a workshop or on an assembly floor. Other types of fluids may be used, such as for example a refrigerant, water, oil, etc.

In some embodiments, a nozzle may be used. For example,FIG. 4illustrates a nozzle426adisposed between the source426and the port434. While shown as a separate device, in some embodiments the nozzle426amay be integrated with the source426.

The nozzle426amay include a vortex tube (also known in the art as a Ranque-Hilsch vortex tube), such as the vortex tube626ofFIG. 6. The vortex tube626may include a fluid input port626aand one or more fluid output ports, such as for example output ports626band626c.

The port626amay be fluidly coupled to the source426. Fluid632areceived from the source426by the port626amay be provided to a chamber636. The fluid in the chamber636may be accelerated/subject to rotation, such that the fluid may be separated into a fluid stream632band a fluid stream632c. The fluid streams632band632cmay be at different temperatures relative to each other, and potentially relative to the fluid632aentering the port626a. For example, the temperature of the fluid632cmay be less than the temperature of the fluid632a, and the temperature of the fluid632amay be less than the temperature of the fluid632b. In this example, the port626cmay be coupled (e.g., fluidly coupled) to the input port434of the plate320(seeFIGS. 3-4) in order to provide cooled/chilled fluid to the plate320. The cooled/chilled fluid provided to (and received by) the plate320may further enhance the cooling that is provided by the plate320to the component stack.

Referring toFIG. 5, a flow chart of an exemplary method500is shown. The method500may be used to assemble one or more components. For example, the method500may be used to assemble a stack of components. For convenience, the method500is described below in relation to the system300ofFIG. 3(and the placement of the bearing212bin the stack ofFIG. 3in particular). One skilled in the art will appreciate that the method500may be adapted to accommodate/conform to other systems, stacks, and/or components.

In block504, the second bearing212bmay be heated. For example, as part of block504, the bearing212bmay be placed in an oven/furnace or subjected to an induction heater. The particular temperature that the bearing212bmay be heated to may be based on one or more application requirements/specifications. In some embodiments, the temperature or time that the heat is applied to the component may be based on a material that the bearing212bis formed from. In some embodiments, the bearing212bmay be heated to a temperature within a range of 149 degrees Celsius to 205 degrees Celsius; other temperature values may be used.

In block510, the bearing212bmay be placed into position relative to the stack. As part of block510, the bearing212b(e.g., the race214b) may be coupled to (e.g., abut) the shaft224and/or may be coupled to (e.g., abut) the spacer218on a first surface212b-1of the bearing212b(e.g., the race214b).

In block516, the plate320may be coupled to the bearing212b. As part of block516, a second surface212b-2of the bearing212b(e.g., the race214b) may be coupled to (e.g., abut) a first surface320-1of the plate320. The surface212b-2may be opposed to the surface212b-1.

In block522, the loading ram240may be coupled to (e.g., abut) the plate320. As part of block522, the loading ram240may abut a second surface320-2of the plate320. The surface320-2may be opposed to the surface320-1.

In block528, the loading ram240may be engaged. Engaging the loading ram240may cause the loading ram240to apply a force/load to the stack. The particular load that is used may be based on parameters associated with an engine that the components of the stack pertain to. For example, the load may be based on materials used for the components, a dimension of one or more of the components, etc. In some embodiments, the loading ram240may apply a load within a range of 10,000 pounds and 50,000 pounds; other values for the load applied by the loading ram240may be used.

In block534, a cooling system (e.g., the cooling system400ofFIG. 4, including the plate320of block516described above) may be engaged. Engagement of the cooling system may include, e.g., transmission and/or receipt of fluid by one or more components, a circulation of cooling fluid in the cooling system, etc., in the manner described above. As part of block534, a cooling fluid may be applied directly to the bearing212b(if permitted as part of the particular application context).

Following a lapse of time during which the cooling system is engaged in block534, the cooling system may be disengaged in block540. The time may be specified based on a threshold temperature that the bearing212bmust cool to. The threshold temperature may be approximately equal to room/ambient temperature in some embodiments. In some embodiments, the threshold temperature may be approximately equal to a temperature of another component, such as for example a temperature of the shaft224. In some embodiments, one or more temperature sensors (not shown) may be included to determine/measure one or more temperatures as part of block540.

In block546, the loading ram240may be disengaged. Disengaging the loading ram240may cause the loading ram240to cease applying a force to the stack.

In block552, the loading ram240may be decoupled from the plate320.

In block558, the plate320may be decoupled from, e.g., the bearing212b.

Portions of the method500may be executed as part of an iterative loop to assemble each component of a stack. For example, the blocks504-558may be executed once for each component included in the stack. Once the stack is assembled, flow may proceed to block570wherein any final assembly procedures may be performed.

Block570may include coupling a nut to the stack via a(n automated) torque wrench to hold the components of the stack in their respective positions. Block570may include the performance of one or more tests to determine whether the stack adheres to one or more requirements/specifications.

The method500is illustrative. In some embodiments, one or more of the blocks (or a portion thereof) of the method may be optional. In some embodiments, the blocks may execute in an order or sequence that is different from what is shown inFIG. 5. In some embodiments, additional blocks not shown may be included. In some embodiments, one or more portions of a first block may be integrated with one or more portions of one or more other blocks.

Referring toFIG. 7, a system700for assembling components of an engine are shown. As shown, a first component706and a second component708may be assembled relative to one another as disposed on a shaft724, where the shaft724may include a lip724a. The components706and708may correspond to one or more of the components described above in relation toFIG. 3(e.g., the components706and708may correspond to the seal206, the bearings212aand212b, the spacer218). The shaft724may correspond to the shaft224.

The system700may include a bearing stacking device that includes a housing710, a thermal transfer apparatus720, and a loading ram740. The housing710may include a first (e.g., forward facing) surface710aand a second (e.g., aft facing) surface710b. The housing710(e.g., the surface710a) may abut the component708. The housing710may surround the shaft724. The housing710may contain a plurality of discontinuous exterior surfaces; for example, the surface710aand the surface710bmay be configured for translational movement in relation to one another. Such an example of relative translational movement may occur during operation of the loading ram740.

The thermal transfer apparatus720may (selectively) transfer thermal energy to/from the surface710aand/or the component708. For example, the thermal transfer apparatus720may transfer heat to the surface710a. In some embodiments, the thermal transfer apparatus720may cool the surface710a. The thermal transfer apparatus720may operate on the basis of one or more techniques, such as convection, radiation, conduction, etc. One or more fluids may be used in conjunction with the thermal transfer apparatus720. The transfer of thermal energy to/from the surface710amay control/regulate a temperature associated with, e.g., the component708and/or the shaft724. In some embodiments, the thermal transfer apparatus720may be distinct from the surface710a. In some embodiments, the thermal transfer apparatus720may be integrated with the surface710a.

The loading ram740may correspond to the loading ram240. The loading ram740may position the surface710ain relation (e.g., axial relation) to the component708.

Technical effects and benefits of this disclosure include an ability to quickly cool hardware during assembly. Such cooling may be obtained without necessarily using direct-air cooling that may have a tendency to introduce foreign objects/debris. Relative to conventional techniques, the cooling provided herewith may reduce the time it takes to assemble the hardware without sacrificing quality in the assembly (e.g., without introducing gaps between components in a stack).

Aspects of the disclosure have been described in terms of illustrative embodiments thereof. Numerous other embodiments, modifications, and variations within the scope and spirit of the appended claims will occur to persons of ordinary skill in the art from a review of this disclosure. For example, one of ordinary skill in the art will appreciate that the steps described in conjunction with the illustrative figures may be performed in other than the recited order, and that one or more steps illustrated may be optional in accordance with aspects of the disclosure. One or more features described in connection with a first embodiment may be combined with one or more features of one or more additional embodiments.