Patent Description:
Gas turbine engines are known and typically include a fan delivering air into a bypass duct as propulsion air. The fan also delivers air into a compressor where it is mixed with fuel and ignited. Products of this combustion pass downstream over turbine rotors driving them to rotate.

As can be appreciated, a gas turbine engine is a very complex system. Lubricant is required at any number of locations. One such location is to bearings which support the rotating turbine rotors. A scavenge system returns the lubricant after it has lubricated the bearings. The scavenge system includes a scavenge tube which extends through housings. There are seals to seal the scavenge tube within the housings. Also, housings, fittings and tubes may leak. As examples, braze joints and nut fittings may leak.

It is difficult to test the scavenge tube for leakage and, in particular due to the crowded environment in which at least one scavenge tube sits.

<CIT> describes test plugs for tightness tests and leakage measurements on gas-carrying pipes of a pipe network.

<CIT> describes an apparatus for passing fluid into a conduit for pressure testing said conduit.

<CIT> describes a gear reduction for a gas turbine engine comprising a carrier driven to rotate gears.

<CIT> describes an apparatus for sealing off pipes and openings is provided, in which apparatus a gripping device takes hold of a pipe nozzle, and a clamping device, which is mounted in the apparatus, presses a rubber seal onto the opening to be sealed.

In accordance with a first aspect, there is provided a method of providing a pressure test on a tube to identify leakage as recited in claim <NUM>.

In another embodiment according to any of the previous embodiments, after said lever is pivoted, a pin is inserted to lock the lever at the pivoted position.

In another embodiment according to any of the previous embodiments, the inlet is positioned adjacent obstructions.

In another embodiment according to any of the previous embodiments, the obstructions include at least a crossover tube.

In another embodiment according to any of the previous embodiments, the tube is configured to return oil to an oil sump.

In another embodiment according to any of the previous embodiments, the method identifies a leaking seal, housing, tube, joints or connections.

In another embodiment according to any of the previous embodiments, the forceps locks include clamps to lock on the outer peripheral surface above of the tube end prior to the movement of step (b).

The geared architecture <NUM> may be an epicycle gear train, such as a planetary gear system or other gear system, with a gear reduction ratio of greater than about <NUM>:<NUM>.

<FIG> shows a turbine intermediate case <NUM> which is mountable within the gas turbine engine of <FIG>. As shown, a bearing support <NUM> may support shafts associated with the rotors in the turbine section. It is known to supply lubricant to various locations in the turbine intermediate case including the bearing area. It is also known to provide a scavenge tube <NUM> to return the lubricant back to a lubricant sump. The scavenge tube extends into a bracket or housing <NUM> and seals <NUM> are located at the area. Internal to the bearing support <NUM> and the housing <NUM>, the scavenge tube <NUM> communicates into a scavenge tube end <NUM> having an inlet <NUM>. The tube <NUM> has a portion <NUM> extending through another housing <NUM>, which may also include seals. This is returned to an oil sump located at some remote location.

As is clear from <FIG>, the inlet <NUM> is spaced quite closely to a crossover tube <NUM> which has a distinct function. Thus, space is limited adjacent the inlet <NUM>.

<FIG> shows the tube <NUM> removed from the housing <NUM>, and illustrates the location of a seal <NUM>. It would be desirable to test the scavenge tube <NUM>/<NUM> for leakage without having to disassemble the system. Thus, a pressure test would be desirable. However, to perform a pressure test, one must seal the inlet <NUM> and apply pressure to a remote end of the tube <NUM>. While a seal is shown, as mentioned above there are other potential leakage locations to test.

<FIG> shows a tool <NUM> have forceps <NUM> with a ratchet clamping lock <NUM>. Semi-circular grippers <NUM> and <NUM> will lock onto the tube <NUM>, as disclosed below. A plug <NUM> will move into the inlet <NUM>. The plug <NUM> is mounted into an end <NUM>. An actuation structure <NUM> is actuated by a lever <NUM> to cause the plug <NUM> to move in an axial direction.

<FIG> is a crosscut view and shows the actuation structure <NUM>. When the lever <NUM> is pivoted, it causes the actuation structure <NUM> to move a portion <NUM> on an end <NUM> of an actuator link <NUM>. Actuator link <NUM> extends to the mount <NUM> which receives a ball mount <NUM> associated with the plug <NUM>. A washer <NUM> is provided to transmit force to gripper vanes <NUM>. An oil ring seal <NUM> and a chamfer <NUM> may be included.

As shown in <FIG>, the lever <NUM> and the actuation structure <NUM> is in the non-actuated position.

<FIG> shows the lever <NUM> having been pivoted clockwise in this view with the actuation structure also pivoting and providing a force against the forceps <NUM> to draw the seal <NUM> to the right, in this view. A pin <NUM> locks the lever <NUM> in this lock or sealing position.

As can be appreciated from <FIG>, pin <NUM> extends through end <NUM>. When the lever <NUM> is pivoted to the <FIG> position one can see the pin is moved to the right. Seal <NUM> is then pulled to the right.

<FIG> shows a test position for the tool <NUM>. Initially the seal may be brought under the tube <NUM> and then upwardly into the inlet <NUM>. Then, the forceps <NUM> could be locked. The forceps <NUM> have the clamp portions (or "forceps locks") <NUM> and <NUM> locked on to an outer peripheral surface <NUM> of the tube <NUM> adjacent an end near inlet <NUM>. The plug <NUM> is received within the inlet <NUM> sealing the inlet. Although this structure is all close to the tube <NUM>, there is adequate room to mount the tool <NUM>.

<FIG> is a distinct view and shows the plug <NUM> in the inlet <NUM>. The lever <NUM> is moved to the lock position to cause the plug <NUM> to be moved into the inlet.

<FIG> shows a pin <NUM> inserted in a hole <NUM> to lock lever <NUM> at the lock position during testing.

As shown in <FIG> and <FIG> schematically, the tube <NUM> is connected to a pressure source <NUM>. Once the tool has sealed the inlet <NUM>, pressure can be applied on the tube <NUM> and the pressure may be monitored. If the pressure drops more than a predetermining amount in a particular period of time, then a leak may be identified. Once the test is over, the tool is easily removed and the engine may be either repaired or moved back to service, as appropriate.

A method of providing a pressure test on a tube to identify leakage includes the steps of mounting a clamp on a tube adjacent to an end and such that a plug which is part of the tool is positioned to plug an opening in the inlet. The method also actuates the tool to cause the plug to provide a fluid tight seal in the inlet. A source of pressure is applied to the tube. The pressure within the tube is monitored, and a leak is identified should the pressure drop more than a predetermined amount in a particular period of time.

Claim 1:
A method of providing a pressure test on a tube to identify leakage;
wherein said tube is a tube end (<NUM>) connected to a bearing support (<NUM>) and a scavenge tube (<NUM>) is connected to a portion of a housing (<NUM>), wherein said housing (<NUM>) is a turbine intermediate case (<NUM>) in a gas turbine engine (<NUM>), and wherein said scavenge tube (<NUM>) is in fluid communication with said tube end (<NUM>);
the method including the steps of:
(a) mounting a tool (<NUM>) including a clamp on a tube adjacent an end and such that a plug (<NUM>) which is part of said tool (<NUM>) is positioned to plug an inlet (<NUM>) into said tube, wherein said tool (<NUM>) includes forceps locks (<NUM>, <NUM>), which lock on an outer peripheral surface (<NUM>) above of said tube end (<NUM>) prior to the movement of step (b);
(b) actuating said tool (<NUM>) to cause said plug (<NUM>) to provide a fluid tight seal in the inlet (<NUM>), wherein a lever (<NUM>) on said tool (<NUM>) is pivoted to cause said plug (<NUM>) to be moved axially into said inlet (<NUM>); and
(c) applying a source of pressure (<NUM>) to said tube, wherein the pressure source (<NUM>) is applied to a remote end of said scavenge tube (<NUM>) relative to said tube end (<NUM>), and monitoring the pressure within said tube, and identifying a leak should said pressure drop more than a predetermined amount in a particular period of time.