Rotor loading system

A rotor loading system for an aircraft turbine engine has a first tool having first proximal and first distal ends. The first proximal end defines a traction interface about a first axis and a first surface radially outward of the traction interface. The first distal end defines first projections spaced circumferentially and extending to outward of the first surface. The system has a second tool with second proximal and second distal ends. The second proximal end defines a torque interface about a second axis and a second surface radially outward of the torque interface. The second distal end defines second projections spaced circumferentially and extending to outward of the second surface. One of the first and the second tool is received by the other one of the tools such that: the first and the second axis are colinear and each of the first projections is received between two second projections.

TECHNICAL FIELD

The application relates generally to rotors of aircraft turbine engines and, more particularly, to the assembly and disassembly of such rotors and tools for doing same.

BACKGROUND OF THE ART

Engines, such as turbine engines, have rotors that are rotatably mounted inside shrouds with relatively small clearances between the rotors and the shrouds. The assembly or disassembly of some rotors, whether during initial building of the engine or during maintenance, is a time-consuming and costly enterprise that entails the assembly or disassembly of neighboring components in order to make room for suitable handling of such rotors.

SUMMARY

In accordance with an aspect of the present technology, there is provided a rotor loading system for an aircraft turbine engine, the rotor loading system comprising: a first tool having opposite first proximal and first distal ends, the first proximal end defining a traction interface about a first axis connectable to a traction device and a first peripheral surface radially outward of the traction interface, the first distal end defining a plurality of first projections spaced circumferentially from one another about the first axis and extending to radially outward of the first peripheral surface; a second tool having opposite second proximal and second distal ends, the second proximal end defining a torque interface about a second axis connectable to a torque device and a second peripheral surface radially outward of the torque interface, the second distal end defining a plurality of second projections spaced circumferentially from one another about the second axis and extending to radially outward of the second peripheral surface; wherein a one of the first and the second tool is received by a remaining one of the first and the second tool such that: the first axis and the second axis are colinear; each one of the first projections is received between two consecutive second projections of the plurality of second projections.

In accordance with another aspect of the present technology, there is provided a rotor loading system for an aircraft turbine engine, the rotor loading system comprising: a first tool having opposite first proximal and first distal ends, the first proximal end defining a traction interface about a first axis connectable to a traction device and a first peripheral surface radially outward of the traction interface, the first distal end defining a plurality of first projections spaced circumferentially from one another about the first axis and extending to radially outward of the first peripheral surface; a second tool having opposite second proximal and second distal ends, the second proximal end defining a torque interface about a second axis connectable to a torque device and a second peripheral surface radially outward of the torque interface, the second distal end defining a plurality of second projections spaced circumferentially from one another about the second axis and extending to radially outward of the second peripheral surface, the second tool having a cavity extending inward the second distal end along the second axis, and a plurality of radial channels spaced circumferentially from one another about the second axis and extending radially outwardly from the cavity to between a pair of consecutive second projections, wherein the first proximal end is received into the cavity and each one of the first projections extends through a one of the channels to between two consecutive second projections of the plurality of second projections.

In accordance with yet another aspect of the present technology, there is provided a rotor loading system for an aircraft turbine engine, the rotor loading system comprising: a mounting base; a first tool having opposite first proximal and first distal ends, the first distal end proximate to the mounting base and defining a plurality of first projections spaced circumferentially from one another about a first axis, the first proximal end defining a traction interface about the first axis connectable to a traction device and a first peripheral surface located radially outward of the traction interface, the first projections extending to radially outward of the first peripheral surface; a second tool having opposite second proximal and second distal ends, the second distal end fastened to the mounting base and defining a plurality of second projections spaced circumferentially from one another about a second axis, the second proximal end defining a torque interface about the second axis connectable to a torque device and a second peripheral surface located radially outward of the torque interface, the second projections extending to radially outward of the second peripheral surface, the second tool having a cavity extending inward the second distal end along the second longitudinal axis, wherein the first proximal end is matingly received into the cavity such that the first axis and the second axis are collinear, and each one of the first projections is received between two consecutive second projections of the plurality of second projections.

DETAILED DESCRIPTION

FIG.1illustrates a gas turbine engine10of a type preferably provided for use in subsonic flight, generally comprising in serial flow communication a fan12through which ambient air is propelled, a compressor section14for pressurizing the air, a combustor16in which the compressed air is mixed with fuel and ignited for generating an annular stream of hot combustion gases, and a turbine section18for extracting energy from the combustion gases. A rotor assembly20is shown among rotary parts of the engine10rotatably disposed about an axis CL. The rotor assembly20includes a rotor30and a bearing40mounted thereto and holding the rotor30in alignment with the axis CL. Other rotary parts of the engine10are also provided for example in an accessory gearbox10aof the engine10. The present technology generally relates to systems for mounting a bearing to a rotor. Although the embodiments of the technology described herein are directed to some such systems adapted for mounting the bearing40to the rotor30, i.e., a centrifugal compressor disc of the compressor section14, other embodiments of the technology can be, mutatis mutandis, adapted for mounting another component to another one of the rotary parts of the engine10. Some such rotary parts may be rotatable about the axis CL, such as turbine discs of the turbine section18, whereas others may be rotatable about an axis remote from the axis CL, for example parts located in the accessory gearbox10a.

Turning now toFIG.2, the rotor assembly20is shown isolated from a remainder of the engine10. The rotor30of the rotor assembly20includes a hub32, an impeller34extending radially outwardly from the hub32, and fore and aft hub extensions36,38respectively extending axially from the hub32on either side of the impeller34. It can be seen that the impeller34is semi-enclosed, i.e., is open on a fore side thereof and closed on an aft side thereof. The rotor assembly20also includes the bearing40as well as a gear50and a nut60which are disposed around the fore hub extension36. The bearing40is disposed between the gear50and the hub32and the nut60is disposed next to the gear50opposite the bearing40. An inner race42(FIGS.8and9) of the bearing40is mounted to the fore hub extension26. An outer race44(FIGS.8and9) of the bearing40defines a bracket that is fastenable to a carcass of the engine10(not shown). As shown inFIG.2, the rotor assembly20has opposite fore and aft ends70,80, in this case respectively defined by free ends of the fore and aft hub extensions36,38. The fore end70of the rotor assembly20is structured and arranged to be interchangeably operatively connectable to either one of an axial loading device (or traction device)90(FIG.8) and a rotational loading device (or torquing device)92(FIG.9). InFIG.2, a portion of the torquing device92is shown operatively connected to the nut60. The aft end80of the rotor assembly20is structured and arranged to be operatively connectable to a rotor loading system100. As schematically shown inFIG.3, the aft end80is an annular body defining an opening of a central bore30aof the rotor30extending axially through the rotor30. The aft end80has an annular, axial wall82in which circumferentially-spaced keyways84are defined. The keyways84are in this case radially-extending slots that communicate inwardly with the central bore30ainside the rotor30and outwardly with outside the rotor30. Stated otherwise, the keyways84extend radially from an innermost diameter of the axial wall82to an outermost diameter of the axial wall82, although other shapes are contemplated. The keyways84each define an axially-oriented bottom surface84aand a pair of circumferentially-oriented side surfaces84bon either side of the bottom surface84a. Portions of the axial wall82located adjacent to the keyways84may be referred to as axial surfaces82a. As will be described in greater detail herein below, the rotor loading system100is cooperable with the traction device90or with the torquing device92, respectively, to impart a rated axial (or compression) load L1or a rated rotational (or torque) load L2to the rotor assembly20to place the bearing40and the gear50into suitable mounted positions relative to the rotor30. Thus, the axial surfaces82aof the axial wall82and the side surfaces84bof the keyways84are sized to be suitable for bearing the rated axial load L1and the rated rotational load L2, respectively.

With reference toFIGS.4-6, the rotor loading system100, referred to henceforth as the loading system100, will now be described in greater detail. The loading system100generally includes a mounting base110adapted to support a remainder of the loading system100, a first tool120having a traction interface120aconnectable to the traction device90(FIG.8) and a first effector120b(FIG.5) for effecting a load imparted by the traction device90to the rotor assembly20, and a second tool130having a torque interface130aconnectable to the torquing device92(FIG.9) and a second effector130b(FIG.5) for effecting a load imparted by the torquing device92to the rotor assembly20. The first and second tools120,130are arranged to be simultaneously positionable relative to the rotor30such that the traction interface120aand the torque interface130aare both received inside the central bore30awhereas the first and second effectors120b,130bare engageable with the aft end80of the rotor30via the axial wall82and the keyways84, respectively.

Referring toFIG.4, the mounting base110is a body arranged to be mounted to a supporting structure that is suitable for supporting the loading system100and the rotor assembly20. For this purpose, a bottom side of the mounting base110defines a mounting interface to which a complementary interface of the supporting structure may latch on. In other embodiments, the mounting base110is instead arranged to be mounted to the supporting structure via fasteners. It is also contemplated that the mounting interface of the mounting base110may be at a location other than the bottom side, for example at one or more side walls of the mounting base110. The supporting structure may be for instance a table T (FIG.2) on which the rotor assembly20may be assembled, or a bridge B (FIG.6) via which the engine10may be stripped of the rotor assembly20either in full or in part. A top side of the mounting base110opposite the bottom side defines a supporting interface onto which the first tool120and the second tool130may be positioned to be held via the mounting base110toward a reference direction R. In this position, the second tool130is connectable to the mounting base110so as to be held stationary relative thereto, whereas the first tool120has a range of motion M (FIG.7) so as to be movable relative to the mounting base110in the reference direction R. The range of motion M may be confined by the second tool130in the reference direction R, and by the mounting base110in the direction opposite the reference direction R. In this embodiment, the mounting base110has a discoid shape and the top and bottom sides are flat, although other shapes are contemplated. It is contemplated that in some embodiments, the mounting base110and the second tool130may form an integral piece. Stated otherwise, the second tool130may be arranged to be mountable directly to the supporting structure, in which case the mounting base110may be omitted.

As best seen inFIG.5, the first and second tools120,130are elongated bodies respectively extending longitudinally about a first axis A1and a second axis A2. The first tool120has a first proximal end122and an opposite first distal end124spaced from one another along the first axis A1. The first proximal end122defines the traction interface120aabout the first axis A1, and defines a first peripheral surface126radially outward of the traction interface120a. The first distal end124defines the first effector120b, i.e., a plurality of first projections128that are spaced circumferentially from one another about the first axis A1. The first projections128extend to radially outward of the first peripheral surface126. The second tool130has a second proximal end132and an opposite second distal end134spaced from one another along the second axis A2. The second proximal end132defines the torquing interface130aabout the second axis A2, and defines a second peripheral surface136radially outward of the torquing interface130a. The second distal end134defines the second effector130b, i.e., a plurality of second projections138that are spaced circumferentially from one another about the second axis A2. The second projections138extend to radially outward of the second peripheral surface136.

Depending on the embodiment, one of the first and second tools120,130(i.e., an innermost tool) is receivable by a remaining one of the first and second tools120,130(i.e., an outermost tool) such that the first and second axes A1, A2are collinear, the first and the second proximal ends122,132face toward a common direction, and each one of the first projections128is received between two consecutive second projections138. When the first and second tools120,130are supported by the mounting base110, the common direction corresponds to the reference direction R.

In the depicted embodiment, the first tool120is receivable by the second tool130. Hence, the first tool120is the innermost tool, and the second tool130is the outermost tool. The second tool130defines a cavity130cthat extends inward of the second distal end134and is sized for receiving the first proximal end122. The cavity130chas a peripheral wall shaped complementarily to a shape of the first peripheral surface126. The shape of the first peripheral surface126is cylindrical, although other shapes are contemplated. The second tool130also defines a plurality of channels130dspaced circumferentially from one another about the second axis A2. Each one of the channels130dextends radially outwardly between a pair of consecutive second projections138, from the cavity130cto outside the second tool130. Each one of the channels130dis sized for receiving one of the first projections128.

Also, in some embodiments, the loading system100further includes a protector sleeve140(best seen inFIG.4) having an interior sized to receive the distal portion of the outermost tool, and an exterior sized to fit the central bore30a. The protector sleeve140may thus act as a bushing for precisely aligning the loading system100with the axis A as it enters the central bore30a. In such embodiments, the first and second projections128,138respectively extend to radially outward of the protector sleeve140. As shown inFIG.6, the first projections128are circumscribed by a first diameter ϕ1. The second projections138are circumscribed by a second diameter ϕ2which generally corresponds to an outer diameter of the aft portion80of the rotor30(FIG.2). The protector sleeve140is circumscribed by a third diameter ϕ3that corresponds to a diameter of the central bore30a. The third diameter ϕ3is smaller than either one of the first diameter ϕ1and the second diameter ϕ2. Advantageously, the protector sleeve140may be constructed of a material suitable for mitigating damage otherwise caused to the rotor30should the loading system100contact the rotor30. Some such materials include plastics and metals of a hardness that is less than that of the material of which the rotor30is constructed, among other possibilities. In some such embodiments, the protector sleeve140defines an indicator142arranged to be circumferentially aligned with one of the first projections128or one of the second projections138. For instance, the protector sleeve140may be in a rotationally indexed position with respect to the second tool130about the second axis A2so as to align with one of the second projections138(FIG.4) or with one of the channels130d. One or more fasteners144may be used to hold the protector sleeve140in the rotationally indexed position relative to the second tool130. In other embodiments, the second proximal end132of the second tool130is sized to fit the central bore30a. In some such embodiments, the protector sleeve140is a coating applied to the second proximal end132. In other such embodiments, the protector sleeve140is omitted.

InFIG.6, it can also be seen that in this embodiment, the first diameter ϕ1is smaller than the second diameter ϕ2. Stated otherwise, the first projections128extend to radially outward of the second projections138and to radially outward of the aft end80of the rotor30. A first circumferential width W1of the first projections128corresponds to a circumferential width of the axial surfaces82a, and a second circumferential width W2of the second projections138corresponds to a circumferential width of the keyways84. In this case, the first circumferential width W1is greater than the second circumferential width W2. Conversely, the circumferential width of the axial surfaces82ais greater than the circumferential width of the keyways84, which favors the structural integrity of the rotor30.

With reference toFIGS.6to9, functional characteristics of the loading system100will now be described. In order to build the rotor assembly20, the loading system100may be mounted to the table T via the mounting base110such that the reference direction R corresponds to an upward direction relative to a planar horizontal ground surface P. The rotor30may then be positioned above the loading system100, with its aft end80facing down, such that its axis A generally coincides with the axes A1, A2of the loading system100. The rotor30may be rotated about the axis A into a position in which one of the keyways84axially aligns with the indicator142. The rotor30may then be moved toward the table T such that its central bore30areceives the proximal ends122,132of the loading system100until the rotor30is in a seated position relative to the loading system100. In the seated position (FIG.7), the axes A1, A2are collinear to the axis A. The bottom surfaces84aof the keyways84abut the axial surfaces138aof the second projections138, whereas first axial surfaces128aof the first projections128are free to move axially to and from the axial surfaces82aof the axial wall82. Indeed, the axial surfaces82ado not bear against the first axial surfaces128aof the first projections128. The first projections128have a first axial height H1that is smaller than a second axial height H2of the second projections138. Moreover, the keyways84have a depth (i.e., an axial distance between the axial surfaces82aand the bottom surfaces84a) that is less than a difference between the second axial height H2and the first axial height H1. Hence, upon the rotor30being in the seated position, the first tool120is axially slidable relative to the second tool130between a first position and a second position. In the first position, the first axial surfaces128aare offset relative to the second axial surfaces138aby a first distance D1. In the second position, the first axial surfaces128aare offset relative to the second axial surfaces138aby a second distance D2smaller than the first distance D1. In the first position, the first projections128do not contact the aft end80of the rotor30, which could otherwise prevent the rotor30from being fully seated onto the second projections138. The rotor30being fully seated allows to maximize an area of overlap between the side surfaces84bof the keyways84and corresponding side surfaces138bof the second projections138, which may be referred to as a rotational loading area. In the second position, the first axial surfaces128aabut the axial surfaces82a, and an area of overlap therebetween may be referred to as an axial loading area. A difference between the first distance D1and the second distance D2corresponds to the range of motion M of the first tool120. It should be noted that the cavity130cand the channels130dare sized such that the first tool120is slidable relative to the second tool130between the first position and the second position, i.e., across the range of motion M, unhindered. Moreover, the second tool130is arranged such that none of the surfaces defining either the cavity130cor the channels130dbear against the first tool120upon the first tool being in the second position. As such, any axial load exerted by the first tool120in the reference direction R onto the rotor30is fully borne by the axial surfaces82a.

Turning now toFIG.8, the loading system100is mounted to the table T. The rotor30is shown in the seated position and the bearing40and the gear50are disposed on the fore hub extension36albeit not securedly so. A first traction member90aof the traction device90surrounds the fore hub extension36and axially engages the gear50and the bearing40via the gear50, whereas the nut60ofFIG.2is absent. A second traction member90bof the traction device80extends into the rotor30via the central bore30a, through the torquing interface130aand to the traction interface120a. The second traction member90baxially engages the traction interface120a, holding the first tool120in the second position. In the depicted embodiment, the traction interface120ais a threaded bore extending about the first axis A1into the first tool120from the first proximal end122toward the first distal end124. The second traction member90bis a threaded rod shaped complementarily to the traction interface120a. As the traction device90is operated, the second traction member90bis translated relative to the first traction member90ain the reference direction R while the first traction member90ais held stationary, such that opposite, compressive forces are applied onto the rotor assembly20, namely onto the gear50and the bearing40via the first traction member90aand onto the axial surfaces82aof the rotor30via the axial surfaces128aof the first tool128. Upon the rated axial load L1being applied via the first traction member90a, the gear50and the bearing40are deemed to be suitably positioned relative to the rotor30.

InFIG.9, the loading system100has remained mounted to the table T and the rotor30has remained in the seated position. The traction device90has been removed. The nut60has been threadedly engaged with the fore hub extension36so as to axially engage the gear50as well as the bearing40via the gear50. A first torquing member92aof the torquing device92is rotationally engaged with the nut60. A second torquing member92bof the torquing device92extends into the rotor30via the central bore30ato the torquing interface130a. The second torquing member92brotationally engages the torquing interface130asuch that one may not rotate about the second axis A2without the other. In the depicted embodiment, the torquing interface130ais a peripheral wall having an anti-rotational cross section. The anti-rotational cross section has a square shape, although other shapes are contemplated. The second torquing member92bis an elongated body having a cross section shaped complementarily to that of the torquing interface130a. It should be understood that the the torquing interface130aand the second torquing member92bdescribed herein are merely one of various suitable anti-rotational assemblies. As the torquing device92is operated, the first torquing member92ais rotated with the nut60about the second axis A2relative to the second torquing member92b, which is held stationary with the rotor30. As a rotational load is applied to the nut60via the first torquing member92a, an opposite rotational load is applied to the rotor30via the side surfaces138bof the second tool130. In this embodiment, as the first torquing member92ais rotated counterclockwise as viewed in the reference direction R, the first torquing member92aaxially drives the nut60in the direction opposite to the reference direction R, such that the nut60axially loads the gear50as well as the bearing40via the gear50. Upon the rated rotational load L2being applied via the first torquing member92a, the gear50and the bearing40are deemed to be suitably secured relative to the rotor30.

Understandably, the steps described hereinabove can be performed in reverse to disassemble, or strip, the rotor assembly20. Also, in order to strip the rotor assembly20from the engine10, the loading system100may be mounted to the bridge B (FIG.6) via the mounting base110. With the rotor assembly20being installed in the engine10, the axis A of the rotor30is collinear to the axis CL. The loading system100may thus be positioned with the bridge B aft of the rotor assembly20such that the axes A1, A2coincide with the axes A, CL, with the loading system100extending away from the bridge B and toward the central bore30a. The loading system100may then be moved toward the rotor30such that the central bore30areceives the proximal ends122,132of the loading system100until the rotor30is in the seated position relative to the loading system100. In the seated position, opposite ends B1, B2of the bridge B are located adjacent to mounting tabs of the carcass of the engine10, and may be fastened thereto to hold the loading system100stationary relative to the carcass. The loading system100can thus be said to be suitable for guiding the bridge B relative to the carcass of the engine10. With the rotor30in the seated position relative to the loading system100and the loading system100held stationary relative to the carcass via the bridge B, either of the traction device90and the torquing device92can be used to strip the rotor assembly20upon being suitably positioned on the fore side of the engine10.

The embodiments described in this document provide non-limiting examples of possible toolations of the present technology. Upon review of the present disclosure, a person of ordinary skill in the art will recognize that changes may be made to the embodiments described herein without departing from the scope of the present technology. For example, a rotor loading system could be adapted for securing one or more components such as the bearing40and/or the gear50to a rotor other than a centrifugal compressor disc. The rotor loading system could be adapted for securing one or more components to either a fore or an aft side of the rotor. The rotor loading system could be adapted for applications other than securing a component to a rotor of an aircraft turbine engine, for example securing a component to a rotor of an industrial turbine engine, or even to a rotor of a surface (land or marine) vehicle turbine engine. The present technology could even be used in yet other applications such as securing a component to a rotor of an automotive powertrain based on either an internal combustion engine or an electric motor. Yet further modifications could be tooled by a person of ordinary skill in the art in view of the present disclosure, which modifications would be within the scope of the present technology.