초록 ▼

A joint assembly for securing flanges of two casings comprising a plurality of bolts, a plurality of collars and a plurality of nuts. Each bolt extends through an aperture in the first flange and an aperture in the second flange, each collar being arranged around a shank of a respective bolt and eac

A joint assembly for securing flanges of two casings comprising a plurality of bolts, a plurality of collars and a plurality of nuts. Each bolt extends through an aperture in the first flange and an aperture in the second flange, each collar being arranged around a shank of a respective bolt and each nut being secured on a respective one of the bolts. Each collar being arranged between one of the flanges and a nut or a head of a bolt. Each collar comprises a first member and a second member, the second member being arranged at a first end of the first member. The second member being substantially U-shaped in cross-section, the second member having first and second radially inner ends and a radially outer mid portion and an axial space is defined between the first radially inner end and the second radially inner end of the second member.

대표청구항 ▼

1. A joint assembly comprising: a first gas turbine engine casing having a first flange and a second gas turbine engine casing having a second flange, the first and second flanges extending parallel to each other,the first flange having a plurality of first apertures extending there-through,the seco

1. A joint assembly comprising: a first gas turbine engine casing having a first flange and a second gas turbine engine casing having a second flange, the first and second flanges extending parallel to each other,the first flange having a plurality of first apertures extending there-through,the second flange having a plurality of second apertures extending there-through, andthe second apertures in the second flange being aligned with the first apertures in the first flange;a plurality of bolts and a plurality of nuts, each bolt extending through a respective first aperture in the first flange and a respective second aperture in the second flange, and each nut being secured on a respective one of the bolts; andat least one collar, the at least one collar being arranged around a shank of one of the bolts,the at least one collar being arranged between one of the flanges and the respective nut or between one of the flanges and a head of the respective bolt, andthe at least one collar comprising a first member and a second member,the second member being thicker than a mid portion of the first member, the second member being arranged at a first end of the first member,the first member of the collar being annular,the second member having a first radially inner end, a second radially inner end and a radially outer mid portion,the second member between the first radially inner end and the second radially inner end being a unitary monolithic annular member and being substantially U-shaped or V-shaped in cross-section,the second member defining an axial space between the first radially inner end and the second radially inner end of the second member, andthe first member and the second member are structured such that, when a crushing load is applied, the first radially inner end abuts the second radially inner end before the first member is crushed. 2. A joint assembly as claimed in claim 1 comprising: a plurality of collars, each collar being arranged around a shank of a respective bolt,each collar being arranged between one of the flanges and the respective nut or between one of the flanges and a head of the respective bolt, andeach collar comprising a first member and a second member, the second member being arranged at a first end of the first member,the first member being annular,the second member being annular and substantially U-shaped or V-shaped in cross-section,the second member having a first radially inner end, a second radially inner end and a radially outer mid portion, andthe second member defining an axial space between the first radially inner end and the second radially inner end of the second member. 3. A joint assembly as claimed in claim 2 wherein each of a predetermined number of the collars has a greater strength than each of the remaining collars. 4. A joint assembly as claimed in claim 1 wherein: each collar comprises a third member,the third member being arranged at a second end of the first member so that the first member is arranged axially between the second member and the third member,the third member being annular and substantially U-shaped or V-shaped in cross-section,the third member having a third radially inner end, a fourth radially inner end and a second radially outer mid portion, andthe third member defining an axial space between the third radially inner end and the fourth radially inner end of the third member. 5. A joint assembly as claimed in claim 4 wherein the first, second and third members are formed together as a unitary monolithic annular member. 6. A joint assembly as claimed in claim 4 wherein the third and fourth radially inner ends of the third member have the same diameter. 7. A joint assembly as claimed in claim 4 wherein the third radially inner end of the third member and the first member have the same diameter. 8. A joint assembly as claimed in claim 4 wherein the fourth radially inner end of the third member has a greater diameter than the third radially inner end of the third member. 9. A joint assembly as claimed in claim 4 wherein the diameter of the radially outer mid portion of the second member is the same as the diameter of the second radially outer mid portion of the third member. 10. A joint assembly as claimed in claim 4 wherein the diameter of the radially outer mid portion of the second member is greater than or less than the diameter of the second radially outer mid portion of the third member. 11. A joint assembly as claimed in claim 1 wherein: each collar comprises a third member,the third member of the collar being cylindrical, andthe second member of the collar being arranged axially between the first member and the third member. 12. A joint assembly as claimed in claim 11 wherein the first, second and third members are formed together as a unitary monolithic annular member. 13. A joint assembly as claimed in claim 1 wherein the first and second members are formed together as a unitary monolithic annular member. 14. A joint assembly as claimed in claim 1 wherein the first and second radially inner ends of the second member have the same diameter. 15. A joint assembly as claimed in claim 1 wherein the second radially inner end of the second member has a greater diameter than the first radially inner end of the second member. 16. A joint assembly as claimed in claim 1 wherein the first radially inner end of the second member and the first member have the same diameter. 17. A joint assembly as claimed in claim 1 wherein the first casing and the second casing are annular. 18. A joint assembly as claimed in claim 1 wherein the first casing is a fan casing and the second casing is a fan duct intake. 19. A joint assembly as claimed in claim 1 wherein the bolt has a failure load, the collar has a crushing load of 80% of the bolt failure load, the bolt is tightened to a torque of no more than 55% of the bolt failure load and the collar has an activation load of no more than 55% of the bolt failure load. 20. A joint assembly as claimed in claim 1 wherein the radially outer mid portion of the second member has a greater external diameter than the external diameter of the first member. 21. A joint assembly comprising: a first gas turbine engine casing having a first flange and a second gas turbine engine casing having a second flange, the first and second flanges extending parallel to each other,the first flange having a plurality of first apertures extending there-through,the second flange having a plurality of second apertures extending there-through, andthe second apertures in the second flange being aligned with the first apertures in the first flange,a plurality of bolts and a plurality of nuts, each bolt extending through a respective first aperture in the first flange and a respective second aperture in the second flange, and each nut being secured on a respective one of the bolts; andat least one crushable collar, the at least one collar being arranged around a shank of one of the bolts,the at least one collar being arranged between one of the flanges and the respective nut or between one of the flanges and a head of the respective bolt, andthe at least one collar comprising a first member and a second member, the second member being arranged at a first end of the first member,the first member of the collar being annular,the second member having a first radially inner end, a second radially inner end and a radially outer mid portion,the second member between the first radially inner end and the second radially inner end being a unitary monolithic annular member and being substantially U-shaped or V-shaped in cross-section,the second member defining an axial space between the first radially inner end and the second radially inner end of the second member, andthe second member being thicker than a mid portion of the first member,the bolts having a failure load, the collar having a crushing load, the collar being configured such that the crushing load of the collar is less than the failure load of the associated bolt, and the bolts applying a clamping load on the first and second flanges,the collar being configured such that if a load on the joint assembly is greater than the clamping load applied by the associated bolt and is less than the crushing load of the collar, the clamping load applied by the associated bolt is overcome by the load on the joint assembly to allow separation of the first and second flanges,the first member and the second member being structured such that the first radially inner end abuts the second radially inner end before the first member is crushed, andthe collar being configured such that, if a load on the joint assembly is greater than the crushing load, the collar is crushed to allow further separation of the first and second flanges. 22. A joint assembly as claimed in claim 21 wherein the crushing load is 80% of the bolt failure load, the bolt applying the clamping load of no more than 55% of the bolt failure load and the clamping load is overcome by a load on the joint assembly of no more than 55% of the bolt failure load.