Flexible joint for transmitting torque

Abstract

A flexible joint includes an inner pipe defining a joint central axis and having a first member, a second member, and a bellows extending between the first member and the second member, the second member includes an inner spline, an outer sleeve having an adapter end fixedly attached to the first member and a sliding end moveably attached to the second member, the sliding end includes an outer spline that engages the inner spline to allow relative axial movement and to restrict relative rotation between the sliding end and the second member with respect to the joint central axis, an outer pipe surrounding the outer sleeve, and a locking washer positioned between the first member and the outer pipe that rotationally fixes the first member to the outer pipe and axially moveably attaches the first member to the outer pipe with respect to the joint central axis.

Description

FLEXIBLE JOINT FOR TRANSMITTING TORQUEBACKGROUND

[0001] A gas turbine engine typically includes a compressor section, a turbine section, and a combustion section disposed therebetween. The compressor section typically includes multiple stages of rotating compressor blades and stationary compressor vanes to produce compressed air. The combustion section typically includes a plurality of combustor to produce hot working flow by combusting mixture of the compressed air and fuel. The turbine section typically includes multiple stages of rotating turbine blades and stationary turbine vanes to expand the hot working fluid and to convert fluid energy to mechanical energy. The rotating turbine blades and stationary turbine vanes often operate in a high temperature environment and are internally cooled.

[0002] A flexible joint may be used in the gas turbine engine to compensate relative movements between components. The flexible joint allows relative expansion and contraction between components without imparting significant stresses into the interfacing components. The flexible joint may need a torsion protection to achieve high flexibility when undergoing an excessive torsional loading.BRIEF SUMMARY

[0003] In one aspect, a flexible joint is provided. The flexible joint includes an inner pipe defining a joint central axis and having a first member, a second member, and a bellows extending between the first member and the second member, the second member includes an inner spline, an outer sleeve having an adapter end fixedly attached to the first member and a sliding end moveably attached to the second member, the sliding end includes an outerspline that engages the inner spline to allow relative axial movement and to restrict relative rotation between the sliding end and the second member with respect to the joint central axis, an outer pipe surrounding the outer sleeve, and a locking washer positioned between the first member and the outer pipe that rotationally fixes the first member to the outer pipe and axially moveably attaches the first member to the outer pipe with respect to the joint central axis.

[0004] In one aspect, a method for transmitting torque through a flexible joint is provided. The method includes fixedly attaching a fixed end of an outer pipe to a cover plate, axially moveably attaching a locking end of the outer pipe to a first member and rotationally fixedly attaching the locking end to the first member, axially positioning a bellows between the first member and a second member to define an inner pipe, circumferentially positioning an outer sleeve between the outer pipe and the inner pipe, fixedly attaching an adapter end of the outer sleeve to the first member and axially moveably attaching a sliding end of the outer sleeve to the second member, and applying torque to the first member, a first portion of the torque transmitted to the outer pipe, a second portion of the torque transmitted to the bellows, and a third portion of the torque transmitted to the outer sleeve.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0006] FIG. l is a longitudinal sectional view of a gas turbine engine taken along a plane that contains a longitudinal axis or central axis.

[0007] FIG. 2 is a longitudinal section view of a flexible joint for use with the gas turbine engine of FIG. 1.

[0008] FIG. 3 is a section view of the flexible joint of FIG. 2 taken along a plane that contains line 3-3.

[0009] FIG. 4 is a partial perspective view of another flexible joint for use with the gas turbine engine of FIG. 1.

[0010] FIG. 5 is a perspective view of a locking washer of the flexible joint of FIG. 2.

[0011] FIG. 6 is a section view of the flexible joint of FIG. 2 taken along a plane that contains line 6-6.

[0012] FIG. 7 is a perspective view of another locking washer for use with the flexible joint of FIG. 2.

[0013] FIG. 8 is a perspective view of a locking end of an outer pipe for use with the locking washer of FIG. 7.DETAILED DESCRIPTION

[0014] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0015] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed bymultiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0016] It should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including”, “having”, and “comprising”, as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0017] Although the terms “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, these elements, information, functions, or acts should not be limited by these terms. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly, a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0018] In the description, the terms “axial” or “axially” refer to a direction along a longitudinal axis of a gas turbine engine. The terms “radial” or “radially” refer to adirection perpendicular to the longitudinal axis of the gas turbine engine. The terms “downstream” or “aft” refer to a direction along a flow direction. The terms “upstream” or “forward” refer to a direction against the flow direction.

[0019] In addition, the term “adjacent to" may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion, unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0020] FIG. 1 illustrates an example of a gas turbine engine 100 including a compressor section 102, a combustion section 104, and a turbine section 106 arranged along a central axis 112. The compressor section 102 includes a plurality of compressor stages 114 with each compressor stage 114 including a set of stationary compressor vanes 116 or adjustable guide vanes and a set of rotating compressor blades 118. A rotor 134 supports the rotating compressor blades 118 for rotation about the central axis 112 during operation. In some constructions, a single one-piece rotor 134 extends the length of the gas turbine engine 100 and is supported for rotation by a bearing at either end. In other constructions, the rotor 134 is assembled from several separate spools that are attached to one another or may include multiple disk sections that are attached via a bolt or plurality of bolts.

[0021] The compressor section 102 is in fluid communication with an inlet section 108 to allow the gas turbine engine 100 to draw atmospheric air into the compressor section 102. During operation of the gas turbine engine 100, the compressor section 102 draws in atmospheric air and compresses that air for delivery to the combustion section 104. The illustrated compressor section 102 is an example of one compressor section 102 with other arrangements and designs being possible.

[0022] In the illustrated construction, the combustion section 104 includes a plurality of separate combustors 120 that each operate to mix a flow of fuel with the compressed airfrom the compressor section 102 and to combust that air-fuel mixture to produce a flow of high temperature, high pressure combustion gases or exhaust gas 122. Of course, many other arrangements of the combustion section 104 are possible.

[0023] The turbine section 106 includes a plurality of turbine stages 124 with each turbine stage 124 including a number of stationary turbine vanes 126 and a number of rotating turbine blades 128. The turbine stages 124 are arranged to receive the exhaust gas 122 from the combustion section 104 at a turbine inlet 130 and expand that gas to convert thermal and pressure energy into rotating or mechanical work. The turbine section 106 is connected to the compressor section 102 to drive the compressor section 102. For gas turbine engines 100 used for power generation or as prime movers, the turbine section 106 is also connected to a generator, pump, or other device to be driven. As with the compressor section 102, other designs and arrangements of the turbine section 106 are possible.

[0024] An exhaust portion 110 is positioned downstream of the turbine section 106 and is arranged to receive the expanded flow of exhaust gas 122 from the final turbine stage 124 in the turbine section 106. The exhaust portion 110 is arranged to efficiently direct the exhaust gas 122 away from the turbine section 106 to assure efficient operation of the turbine section 106. Many variations and design differences are possible in the exhaust portion 110. As such, the illustrated exhaust portion 1 10 is but one example of those variations.

[0025] A control system 132 is coupled to the gas turbine engine 100 and operates to monitor various operating parameters and to control various operations of the gas turbine engine 100. In preferred constructions the control system 132 is typically micro-processor based and includes memory devices and data storage devices for collecting, analyzing, and storing data. In addition, the control system 132 provides output data to various devices including monitors, printers, indicators, and the like that allow users to interface with the control system 132 to provide inputs or adjustments. In the example of a power generation system, a user may input a power output set point and the control system 132 may adjust the various control inputs to achieve that power output in an efficient manner.

[0026] The control system 132 can control various operating parameters including, but not limited to variable inlet guide vane positions, fuel flow rates and pressures, engine speed,valve positions, generator load, and generator excitation. Of course, other applications may have fewer or more controllable devices. The control system 132 also monitors various parameters to assure that the gas turbine engine 100 is operating properly. Some parameters that are monitored may include inlet air temperature, compressor outlet temperature and pressure, combustor outlet temperature, fuel flow rate, generator power output, bearing temperature, and the like. Many of these measurements are displayed for the user and are logged for later review should such a review be necessary.

[0027] FIG. 2 is a longitudinal section view of a flexible joint 200 for use with the gas turbine engine of FIG. 1. The flexible joint 200 may be disposed at the upstream end of the combustor 120 to receive fuel for the combustor 120.

[0028] The flexible joint 200 has a joint central axis 202. An inner sleeve 204 extends along the joint central axis 202 and is connected to a fuel supply to receive fuel for the combustor 120. The inner sleeve 204 is removably arranged in the flexible joint 200.

[0029] An inner pipe 206 extends along the joint central axis 202 and surrounds the inner sleeve 204. The inner pipe 206 includes a first member 208, a second member 210, and a bellows 212 that extends between the first member 208 and the second member 210. The bellows 212 includes a plurality of corrugations 214 that extends circumferentially around the inner pipe 206.

[0030] The first member 208 includes an outer polygonal socket 216 (better shown in FIG. 6). In the exemplary embodiment shown in FIG. 2 and FIG. 6, the outer polygonal socket 216 is an outer hexagonal socket. In other embodiments, the outer polygonal socket 216 may have shapes other than the outer hexagonal socket, such as an outer pentagon head, or an outer octagon head, etc.

[0031] The second member 210 includes a plurality of grooves 218 that axially extends along and is circumferentially distributed around the second member 210 with respect to the joint central axis 202. The plurality of grooves 218 forms an inner spline.

[0032] An outer sleeve 220 extends along the joint central axis 202 and surrounds the inner pipe 206 from the first member 208 to the second member 210 and surrounds the entireouter surface of the bellows 212. The outer sleeve 220 has an adapter end 222 and a sliding end 224. The adapter end 222 is fixedly attached to the first member 208. A collar 226 is arranged at the adapter end 222 to fixedly attach the outer sleeve 220 to the first member 208 of the inner pipe 206. One end of the collar 226 is fixedly attached to the outer sleeve 220. The other end of the collar 226 is fixedly attached to the first member 208. The collar 226 can have a plurality of segments. For example, the collar 226 may have a first semicircular piece and a second semi-circular piece that are fixedly arranged between the inner pipe 206 and the outer sleeve 220 with small gaps between the first semi-circular piece and the second semi-circular piece. The collar 226 may also be one single full circular piece. The collar 226 and the outer sleeve 220 can be made as one single piece or two separated pieces and attached together.

[0033] The sliding end 224 is moveably attached to the second member 210. The sliding end 224 includes a plurality of teeth 228 that axially extends along and is circumferentially distributed around the sliding end 224 with respect to the joint central axis 202. The plurality of teeth 228 forms an outer spline.

[0034] An outer pipe 230 extends along the joint central axis 202 and surrounds the outer sleeve 220. The outer pipe 230 has a locking end 232 and a fixed end 234. The fixed end 234 is axially and radially and circumferentially fixedly attached to a cover plate 236.

[0035] A locking washer 238 is disposed between the first member 208 and the locking end 232. The locking washer 238 engages the inner pipe 206 and the outer pipe 230 to allow relative axial and radial movements and restrict relative rotation between the inner pipe 206 and the outer pipe 230 with respect to the joint central axis 202.

[0036] FIG. 3 is a section view of the flexible joint 200 of FIG. 2 taken along a plane that contains line 3-3. For better illustration, FIG. 3 is a complete section view of the flexible joint 200 that includes the cut away portion of the flexible joint 200 in FIG. 2.

[0037] Each of the teeth 228 engages one of the grooves 218 that forms a spline engagement between the inner pipe 206 and the outer sleeve 220. The spline engagement allows relative axial and radial movements and restricts relative rotation between the innerpipe 206 and the outer sleeve 220 with respect to the joint central axis 202. A small clearance may be arranged between each of the teeth 228 and the engaged groove 218 to allow only a small degree of relative rotation between the inner pipe 206 and the outer sleeve 220.

[0038] FIG. 3 shows the inner pipe 206 has six grooves 218 and the outer sleeve 220 has six teeth 228. In other embodiments, the inner pipe 206 may have less or more than six grooves 218 and correspondingly the outer sleeve 220 may have less or more than six teeth 228 as design required, such as three, five, eight, ten, twenty, one hundred, two hundred, etc.

[0039] FIG. 3 also shows that the grooves 218 are arranged on the inner pipe 206 and the teeth 228 is arranged on the outer sleeve 220. In other embodiments, the grooves 218 may be arranged on the outer sleeve 220 and correspondingly the teeth 228 may be arranged on the inner pipe 206.

[0040] FIG. 4 is a partial perspective view of another flexible joint 200 for use with the gas turbine engine 100. For better illustration, the outer pipe 230 is removed in FIG. 4.

[0041] The inner pipe 206 includes a plurality of tabs 402 that axially extends along and is circumferentially distributed around the second member 210 with respect to the joint central axis 202. The plurality of tab 402 forms an inner spline.

[0042] The outer sleeve 220 includes a plurality of slots 404 that axially extends along and is arranged circumferentially around the sliding end 224 with respect to the joint central axis 202. The slots 404 are axially closed-ended. The plurality of slots 404 forms an outer spline.

[0043] Each of the tab 402 engages one of the slot 404 forms a spline engagement between the inner pipe 206 and the outer sleeve 220. The spline engagement allows relative axial and radial movements and restricts relative rotation between the inner pipe 206 and the outer sleeve 220 with respect to the joint central axis 202. A small clearance may be arranged between each of the tab 402 and the engaged slot 404 to allow only a small degree of relative rotation between the inner pipe 206 and the outer sleeve 220.

[0044] FIG. 5 is a perspective view of the locking washer 238. The locking washer 238 has a washer inner surface 502 and a washer outer surface 504. An inner polygonal socket 506 is arranged on the washer inner surface 502. In the exemplary embodiment shown in FIG. 5, the inner polygonal socket 506 is an inner hexagonal socket. In other embodiments, the inner polygonal socket may have shapes other than the inner polygonal socket, such as an inner pentagon head, or an inner octagon head, etc.

[0045] A plurality of teeth 508 is arranged on the washer outer surface 504. The plurality of teeth 508 axially extends along and is circumferentially distributed around the washer outer surface 504 with respect to the joint central axis 202. The plurality of teeth 508 radially extends from the washer outer surface 504. The plurality of teeth 508 forms a washer spline. The number of teeth 508 varies as design required. For example, the number of teeth 508 can be three, ten, twenty, one hundred, two hundreds, etc.

[0046] FIG. 6 is a section view of the flexible joint 200 of FIG. 2 taken along a plane that contains line 6-6. For better illustration, FIG. 6 is a complete section view of the flexible joint 200 that includes the cut away portion of the flexible joint 200 in FIG. 2.

[0047] The locking washer 238 is disposed between the inner pipe 206 and the outer pipe 230. The outer polygonal socket 216 of the inner pipe 206 engages the inner polygonal socket 506 of the locking washer 238 to couple the inner pipe 206 with the locking washer 238 and to restrict relative rotation between the inner pipe 206 and the locking washer 238 with respect to the joint central axis 202. A small clearance may be arranged between the outer polygonal socket 216 and the inner polygonal socket 506 for thermal expansion.

[0048] The outer pipe 230 includes a plurality of grooves that forms a pipe spline. Each of the teeth 508 of the locking washer 238 engages one of the grooves of the outer pipe 230 forms a spline engagement between the locking washer 238 and the outer pipe 230. The spline engagement allows relative axial and radial movements and restricts relative rotation between the locking washer 238 and the outer pipe 230 with respect to the joint central axis 202. A small clearance may be arranged between each of the teeth 508 and the engaged groove to allow only a small degree of relative rotation between the locking washer 238 and the outer pipe 230.

[0049] FIG. 7 is a perspective view of another locking washer 238 for use with the flexible joint 200. The locking washer 238 includes a plurality of holes 702 that is arranged on the washer outer surface 504. The plurality of holes 702 axially extends along and is circumferentially distributed around the washer outer surface 504 with respect to the joint central axis 202. A plurality of spikes 704 axially extends along and is circumferentially distributed around a washer end surface 706 with respect to the joint central axis 202. In other embodiments, the locking washer 238 may not have the plurality of spikes 704.

[0050] FIG. 8 is a perspective view of a locking end 232 of an outer pipe 230 for use with the locking washer 238 of FIG. 7. The outer pipe 230 has a pipe end surface 806. A plurality of pins 802 axially extends from and is circumferentially distributed around the pipe end surface 806 with respect to the joint central axis 202. The plurality of pins 802 extends parallel to the joint central axis 202. Each of the plurality of pins 802 may be movably inserted into a hole that is defined on the pipe end surface 806 or fixedly attached to the pipe end surface 806. A plurality of dents 804 is circumferentially distributed around the pipe end surface 806. In other embodiments, the outer pipe 230 may not have the plurality of dents 804.

[0051] In an assembled condition, each of the pins 802 engages one of the holes 702 and each of the spikes 704 also engages one of the dents 804 to couple the locking washer 238 with the outer pipe 230 and to allow relative axial and radial movements between the locking washer 238 and the outer pipe 230. A small clearance may be arranged between each of the pins 802 and the engaged holes 702 to allow only a small degree of relative rotation between the locking washer 238 and the outer pipe 230.

[0052] FIGs. 5-8 illustrate some embodiments to couple the locking washer 238 with the outer pipe 230. It is understood that the locking washer 238 and the outer pipe 230 can be coupled with any suitable ways, such as rough surface on the locking washer 238 that is adjacent to the outer pipe 230, rough surface on the outer pipe 230 that is adjacent to the locking washer 238, or grooves on the locking washer 238 and teeth 508 on the outer pipe 230, etc.

[0053] In operation, torque is applied to the first member 208 of the inner pipe 206. A first portion of the torque is transmitted to the locking washer 238 through the locking engagement between the first member 208 and the locking washer 238 and then transmitted to the outer pipe 230 through the spline engagement between the locking washer 238 and the outer pipe 230. A second portion of the torque is transmitted to the bellows 212. A third portion of the torque is transmitted to the outer sleeve 220 through the spline engagement between the second member 210 and the outer sleeve 220 at the sliding end 224. The spline engagement allows the bellows 212 to axially expand and contract and restricts the bellows 212 to rotate. The anti -rotation feature of the spline engagement and the fixed attachment at the adapter end 222 keep the first member 208 and the second member 210 coaxial and bypass the torque around the bellows 212 to the outer sleeve 220. The first member 208 and the second member 210 are arranged at two ends of the bellows 212. The arrangement of the flexible joint 200 provides anti-rotation control over the two ends of the bellows 212 and transmits the torque applied to the bellows 212 to the outer sleeve 220 and the outer pipe 230. The arrangement limits the torque being reacted through the bellows 212 and improves the operation life of the bellows 212.

[0054] The outer sleeve 220 surrounds the entire outer surface of the bellows 212 which provides a protection to the bellows 212 during handling and assembly. The outer sleeve 220 has a small radial clearance at the sliding end 224 so that the outer sleeve 220 can act as a leakage restrictor of the bellows 212.

[0055] The inner sleeve 204 is removably arranged in the flexible joint 200. The removable arrangement of the inner sleeve 204 provides a clearance between the inner sleeve 204 and the bellows 212 and allows inspection of the inner side of the bellows 212. The inspection can reduce the risk of rubbing between the inner sleeve 204 and the bellows 212.

[0056] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0057] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.LISTING OF DRAWING ELEMENTS100 gas turbine engine102 compressor section104 combustion section106 turbine section108 inlet section110 exhaust portion112 central axis114 compressor stage1 16 stationary compressor vane118 rotating compressor blade120 combustor122 exhaust gas124 turbine stage126 stationary turbine vanerotating turbine blade turbine inlet control system rotor flexible joint joint central axis inner sleeve inner pipe first member second member bellows corrugation outer polygonal socket groove outer sleeve adapter end sliding end collar teeth outer pipelocking end fixed end cover plate locking washer tab slot washer inner surface washer outer surface inner polygonal socket teeth pipe inner surface groove hole spike washer end surface pin dent pipe end surface

Claims

CLAIMSWhat is claimed is:

1. A flexible joint comprising: an inner pipe defining a joint central axis and having a first member, a second member, and a bellows extending between the first member and the second member, the second member comprising an inner spline; an outer sleeve having an adapter end fixedly attached to the first member and a sliding end moveably attached to the second member, the sliding end comprising an outer spline that engages the inner spline to allow relative axial movement and to restrict relative rotation between the sliding end and the second member with respect to the joint central axis; an outer pipe surrounding the outer sleeve; and a locking washer positioned between the first member and the outer pipe that rotationally fixes the first member to the outer pipe and axially moveably attaches the first member to the outer pipe with respect to the joint central axis.

2. The flexible joint of claim 1, wherein the inner spline comprises a plurality of grooves and the outer spline comprises a plurality of teeth, and wherein each groove is arranged to engage one of the teeth.

3. The flexible joint of claim 1, wherein the inner spline comprises a plurality of tabs and the outer spline comprises a plurality of closed-ended axially extending slots, and wherein each tab is arranged to engage one of the slots.

4. The flexible joint of claim 1, wherein the outer pipe comprises a fixed end and a locking end, wherein the fixed end is axially and radially and circumferentially fixed to a cover plate with respect to the joint central axis, and wherein the locking end engages the locking washer.

5. The flexible joint of claim 4, wherein the locking end comprises a plurality of grooves and the locking washer comprises a plurality of teeth, and wherein each groove isarranged to engage one of the teeth to allow relative axial movement and to restrict relative rotation between the locking end and the locking washer.

6. The flexible joint of claim 4, wherein the locking end comprises a plurality of pins extending parallel to the joint central axis and the locking washer comprises a plurality of holes, and wherein each pin is arranged to engage one of the holes to allow relative axial movement and to restrict relative rotation between the locking end and the locking washer.

7. The flexible joint of claim 1, wherein the first member comprises an outer polygonal socket and the locking washer comprises an inner polygonal socket that engages the outer polygonal socket.

8. The flexible joint of claim 7, wherein the outer polygonal socket comprises an outer hexagonal socket and the inner polygonal socket comprises an inner hexagonal socket.

9. The flexible joint of claim 1, wherein the bellows comprises a plurality of corrugations that extends circumferentially around the inner pipe.

10. The flexible joint of claim 1, further comprising a collar arranged at the adapter end, wherein one end of the collar is fixedly attached to the outer sleeve and the other end of the collar is fixedly attached to the first member.

11. The flexible joint of claim 1, further comprising an inner sleeve that removably extends along the joint central axis and is surrounded by the inner pipe.

12. A method for transmitting torque through a flexible joint, the method comprising: fixedly attaching a fixed end of an outer pipe to a cover plate; axially moveably attaching a locking end of the outer pipe to a first member and rotationally fixedly attaching the locking end to the first member; axially positioning a bellows between the first member and a second member to define an inner pipe; circumferentially positioning an outer sleeve between the outer pipe and the inner pipe;fixedly attaching an adapter end of the outer sleeve to the first member and axially moveably attaching a sliding end of the outer sleeve to the second member; and applying torque to the first member, a first portion of the torque transmitted to the outer pipe, a second portion of the torque transmitted to the bellows, and a third portion of the torque transmitted to the outer sleeve.

13. The method of claim 12, wherein fixedly attaching the fixed end to the cover plate comprises axially and radially and circumferentially fixedly attaching the fixed end to the cover plate.

14. The method of claim 12, wherein the sliding end comprises an outer spline and the second member comprises an inner spline, and wherein axially moveably attaching the sliding end to the second member comprises engaging the outer spline with the inner spline.

15. The method of claim 12, further comprising coupling the locking end to the first member through a locking washer positioned between the first member and the locking end.

16. The method of claim 15, wherein the locking end comprises a plurality of grooves and the locking washer comprises a plurality of teeth, and wherein coupling the locking end to the first member comprises engaging each groove with one of the teeth to allow relative axial movement and to restrict relative rotation between the locking end and the locking washer.

17. The method of claim 15, wherein the locking end comprises a plurality of pins and the locking washer comprises a plurality of holes, and wherein coupling the locking end to the first member comprises engaging each pin with one of the holes to allow relative axial movement and to restrict relative rotation between the locking end and the locking washer.

18. The method of claim 15, wherein the first member comprises an outer polygonal socket and the locking washer comprises an inner polygonal socket, and wherein coupling the locking end to the first member comprises engaging the inner polygonal socket with the outer polygonal socket to fixedly attaching the locking washer and the first member.

19. The method of claim 12, further comprising positioning a plurality of corrugations on the bellows that extends circumferentially around the inner pipe.

20. The method of claim 12, wherein the adapter end comprises a collar, and wherein fixedly attaching the adapter end of the outer sleeve to the first member comprises fixedly attaching one end of the collar to the outer sleeve and fixedly attaching the other end of the collar to the first member.

Images