Instrumentation Boss For Fan Containment Case

Patent metadata

Field	Value
Publication number	US-2016010503-A1
Application number	US-201514613755-A
Country	US
Kind code	A1
Filing date	Feb 4, 2015
Priority date	May 22, 2014
Publication date	Jan 14, 2016
Grant date	—

Abstract

A method for installing a mounting hole through a wall of a fan case of a gas turbine engine is disclosed. The method may comprise: 1) installing a pilot hole through the wall of the fan case at an angle perpendicular to an outer surface of the wall, 2) inserting a boss through the pilot hole, 3) bonding the boss to the wall of the fan case, and 4) installing the mounting hole through the boss at an off-axis angle with respect to the angle perpendicular to the outer surface of the wall.

First claim

What is claimed is:

1 . A method for installing a mounting hole through a wall of a fan case of a gas turbine engine, comprising:
installing a pilot hole through the wall of the fan case at an angle perpendicular to an outer surface of the wall; inserting a boss through the pilot hole; bonding the boss to the wall of the fan case; and installing the mounting hole through the boss.

2 . The method of claim 1 , wherein installing the mounting hole through the boss includes installing the mounting hole through the boss at an off-axis angle with respect to the angle perpendicular to the outer surface of the wall.

3 . The method of claim 2 , wherein bonding the boss to the wall of the fan case includes adhesively bonding the boss to the wall of the fan case.

4 . The method of claim 3 , wherein the boss comprises a base and an insertion tab extending from a bottom surface of the base, and wherein inserting the boss through the pilot hole includes inserting the insertion tab through the pilot hole.

5 . The method of claim 4 , wherein bonding the boss to the wall of the fan case further includes fixing a width of an adhesive bond between the bottom surface and the outer surface of the wall using at least one bond bump extending from the bottom surface of the base.

6 . The method of claim 5 , wherein bonding the boss to the wall of the fan case further includes fixing a width of an adhesive bond between the insertion tab and a wall of the pilot hole using at least one o-ring encircling the insertion tab.

7 . The method of claim 6 , wherein inserting the boss through the pilot hole further includes centering the boss in the pilot hole using the at least one o-ring.

8 . The method of claim 7 , wherein inserting the boss through the pilot hole further includes aligning a curvature of the bottom surface of the base with a curvature of the outer surface of the wall of the fan case by aligning an indicating feature of the boss with an indicating feature of the fan case.

9 . The method of claim 8 , further comprising installing at least one fastener hole through the boss.

10 . The method of claim 9 , further comprising:
inserting an instrument through the mounting hole; and fastening the instrument to the boss using at least one fastener.

11 . A fan case for a gas turbine engine, comprising:
a circumferentially-extending wall formed at least in part from a composite material and having a pilot hole extending therethrough at an angle perpendicular to an outer surface of the wall; and a boss bonded to the fan case comprising
a base,
an insertion tab extending from a bottom surface of the base and through the pilot hole, and
a mounting hole extending through the boss.

12 . The fan case of claim 11 , wherein the mounting hole extends through the boss at an off-axis angle with respect to the angle perpendicular to the outer surface of the wall.

13 . The fan case of claim 12 , wherein the boss is adhesively bonded to the wall of the fan case.

14 . The fan case of claim 13 , wherein the boss is formed from aluminum.

15 . The fan case of claim 13 , wherein the insertion tab includes at least one o-ring encircling a periphery of the insertion tab.

16 . The fan case of claim 15 , wherein the at least one o-ring centers the boss in the pilot hole.

17 . The fan case of claim 16 , wherein the bottom surface of the base includes at least one bond bump extending radially from the insertion tab, and wherein the at least one bond bump fixes a width of an adhesive bond between the bottom surface of the base and the outer surface of the wall of the fan case.

18 . The fan case of claim 18 , wherein the bottom surface of the base further includes a curvature matching a curvature of the outer surface the wall.

19 . The fan case of claim 19 , wherein the boss further comprises at least one indicating feature to indicate an alignment of the curvature of the bottom surface of the base with the curvature of the outer surface of the wall.

20 . A boss for mounting an instrument on a composite fan case of a gas turbine engine, comprising:
a base; an insertion tab extending from a bottom surface of the base, the insertion tab being configured to insert through a pilot hole that extends through a wall of the composite fan case at an angle perpendicular to an outer surface of the wall; and a mounting hole extending through the boss at an off-axis angle with respect to the angle perpendicular to the outer surface of the wall.

Assignees

• United Technologies Corp

Inventors

• Robertson Jr Thomas J
• Costa Mark W
• Clarkson Steven

Classifications

• F01D25/24

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F05D2240/90

  Mounting on supporting structures or systems · CPC title

• F05D2300/603

  Composites; e.g. fibre-reinforced · CPC title

• F01D25/28 Primary

  Supporting or mounting arrangements, e.g. for turbine casing · CPC title

• G01D11/30

  Supports specially adapted for an instrument; Supports specially adapted for a set of instruments · CPC title