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EP-4737779-A2 - METHOD OF REDUCING SADDLE CLAMP ASSEMBLY STRESS

EP4737779A2EP 4737779 A2EP4737779 A2EP 4737779A2EP-4737779-A2

Abstract

A method of assembling a tube assembly (100) includes the steps of providing a saddle clamp (104) having a first clamp half (109) extending for less than 50 percent of a circumference of a tube (102), and a second clamp half (108) extending for more than 50 percent of the circumference of the tube (102), placing a tube (102) on the first clamp half (109), resting on a static structure (106), and applying a lubricant (122) to a laterally inner surface (117) of the second clamp half (108) and then bringing the second clamp half (108) onto the tube (102), and then driving a fastener (110) to secure the first and second clamp halves (108, 109). A gas turbine engine (20) is also disclosed.

Inventors

  • CZARNIECKI, Gage
  • LOPEZ PADILLA, Jose L
  • SWOPE, Aaron Jayson
  • SABINO, Gianna Eva Marie

Assignees

  • RTX Corporation

Dates

Publication Date
20260506
Application Date
20251031

Claims (12)

  1. A method of assembling a tube assembly (100) comprising the steps of: providing a saddle clamp (104) having a first clamp half (109) extending for less than 50 percent of a circumference of a tube (102), and a second clamp half (108) extending for more than 50 percent of the circumference of the tube (102); placing a tube (102) on the first clamp half (109), resting on a static structure (106), and applying a lubricant (122) to a laterally inner surface (117) of the second clamp half (108); and then bringing the second clamp half (108) onto the tube (102), and then driving a fastener (110) to secure the first and second clamp halves (108, 109).
  2. The method as set forth in claim 1, where there are a pair of the bolt flanges (116, 118) on opposed sides of the tube (102) for each of the first and second clamp halves (108, 109).
  3. The method as set forth in claim 2, wherein the fastener (110) is initially driven into the bolt flanges (116, 118) on one side of the tube (102), and then a second fastener (110) is driven through the bolt flanges (116, 118) on the other side of the tube (102).
  4. The method of claim 3, wherein each of the first and second halves (108, 109) have a metal underlying structure with outwardly extending bolt flanges (116, 118) and a supporting grommet (114) and the fastener (110) extends through the bolt flanges (116, 118).
  5. The method as set forth in claim 4, wherein the bolt flanges (116) on the second clamp half (108) rest on the bolt flanges (118) of the first clamp half (108).
  6. The method as set forth in any preceding claim, wherein the lubricant (122) is only placed on the inner surface (117) of the second clamp half (108).
  7. The method as set forth in any preceding claim, wherein the fastener (110) secures the saddle clamp (104) to the static structure (106).
  8. The method as set forth in any preceding claim, wherein the lubricant (122) is a liquid.
  9. A gas turbine engine (20) comprising: a compressor section (24), a turbine section (28) and combustor (56); and a tube assembly (100) for routing a fluid for use in the gas turbine engine (20); the tube assembly (100) having a saddle clamp (104) with a first clamp half (109) extending for less than 50 percent of a circumference of a tube (102), and a second clamp half (108) extending for more than 50 percent of the circumference of the tube (102), each of the first and second half (108, 109) having a metal underlying structure with outwardly extending bolt flanges (116, 118) and a supporting grommet (114); the tube (102) supported on the grommets (114) of the first and second clamp halves (108, 109), with the bolt flange (118) of the first clamp half (109) resting on a static structure (106), and a lubricant (122) on a laterally inner surface (117) of the second clamp half (108); and a bolt (110) extending through the bolt flanges (116, 118) to secure the first and second clamp halves (108, 109) to the static structure (106).
  10. The gas turbine engine (20) as set forth in claim 9, where there are a pair of the bolt flanges (116, 118) on opposed sides of the tube (102) for each of the first and second clamp halves (108, 109).
  11. The gas turbine engine (20) as set forth in claim 9 or 10, wherein lubricant (122) is not on the first clamp half (109).
  12. The gas turbine engine (20) as set forth in claim 9, 10 or 11, wherein the lubricant (122) is a liquid.

Description

BACKGROUND This application relates to a method of assembling a saddle clamp over a tube wherein the assembly stress on the saddle clamp parts is reduced. Tubes are utilized in any number of systems to route liquids for various purposes. The tube is preferably maintained in a predictable fixed position by plural clamps. One type of clamp is a so-called saddle clamp. In a saddle clamp a smaller portion of the circumference of the tube is supported on a bottom half. The upper half extends for more than half of the circumference of the tube. The tube is typically placed in the lower half, with bolt flanges on the lower half extending laterally outwardly. The upper half is then moved onto the tube, and forced such that its bolt flanges contact the bolt flanges of the lower half. Typically one side of the halves is bolted then the other side is bolted. As the assembly is occurring, the bottom clamp flange creates a flush mating with a stationary surface below. This generates an anchoring point on a grommet that is part of the lower half. When this occurs, instead of half the clamp stretching half the distance to be installed, the upper half must stretch from that anchoring point around about three quarters of the tube in order to be seated on the other side. When this occurs there is undesirably high stress in the upper half. In particular, the highest stress is on the first bolted bolt flange. One common use of saddle clamps is to mount a tube in gas turbine engines. SUMMARY In a featured embodiment, a method of assembling a tube assembly includes the steps of providing a saddle clamp having a first clamp half extending for less than 50 percent of a circumference of a tube, and a second clamp half extending for more than 50 percent of the circumference of the tube, placing a tube on the first clamp half, resting on a static structure, and applying a lubricant to a laterally inner surface of the second clamp half and then bringing the second clamp half onto the tube, and then driving a fastener to secure the first and second clamp halves. In another embodiment according to the previous embodiment, there are a pair of the bolt flanges on opposed sides of the tube for each of the first and second clamp halves. In another embodiment according to any of the previous embodiments, the fastener is initially driven into the bolt flanges on one side of the tube, and then a second fastener is driven through the bolt flanges on the other side of the tube. In another embodiment according to any of the previous embodiments, each of the first and second halves have a metal underlying structure with outwardly extending bolt flanges and a supporting grommet and the fastener extends through the bolt flanges. In another embodiment according to any of the previous embodiments, the bolt flanges on the second clamp half rests on the bolt flanges of the first clamp half. In another embodiment according to any of the previous embodiments, the lubricant is only placed on the inner surface of the second clamp half. In another embodiment according to any of the previous embodiments, the fastener secures the saddle clamp to the static structure. In another embodiment according to any of the previous embodiments, the lubricant is a liquid. In another embodiment according to any of the previous embodiments, the lubricant is a liquid. In another embodiment according to any of the previous embodiments, the lubricant is only placed on the inner surface of the second clamp half. In another embodiment according to any of the previous embodiments, the fastener secures the saddle clamp to the static structure. In another embodiment according to any of the previous embodiments, the lubricant is only placed on the inner surface of the second clamp half. In another embodiment according to any of the previous embodiments, the lubricant is a liquid. In another embodiment according to any of the previous embodiments, the lubricant is a liquid. In another embodiment according to any of the previous embodiments, the lubricant is only placed on the inner surface of the second clamp half. In another featured embodiment, a gas turbine engine includes a compressor section, a turbine section and combustor. A tube assembly routes a fluid for use in the gas turbine engine. The tube assembly has a saddle clamp with a first clamp half extending for less than 50 percent of a circumference of a tube, and a second clamp half extending for more than 50 percent of the circumference of the tube. Each of the first and second half have a metal underlying structure with outwardly extending bolt flanges and a supporting grommet. The tube is supported on the grommets of the first and second clamp halves, with the bolt flange of the first clamp half resting on a static structure, and a lubricant on a laterally inner surface of the second clamp half. A bolt extends through the bolt flanges to secure the first and second clamp halves to the static structure clamp halves. In ano