Patent ID: 12188417

DETAILED DESCRIPTION

FIG.1schematically illustrates a gas turbine engine20with an epicyclic fan drive gear system48having a rotating carrier that is fed lubricant by a transfer bearing. Oil leakage from the carrier and the transfer bearing is directed into a rotating gutter that imparts momentum to drive the oil into an auxiliary reservoir.

The gas turbine engine20is disclosed by way of example as a two-spool turbofan that generally incorporates a fan section22, a compressor section24, a combustor section26and a turbine section28. The fan section22drives air along a bypass flow path B in a bypass duct defined within a nacelle18, and also drives air along a core flow path C for compression and communication into the combustor section26then expansion through the turbine section28. Although depicted as a two-spool turbofan gas turbine engine in the disclosed non-limiting embodiment, it should be understood that the concepts described herein are not limited to use with two-spool turbofans as the teachings may be applied to other types of turbine engines including three-spool architectures, turbofans, turboprop, open rotor configurations and any other gas turbine engine architecture.

The exemplary engine20generally includes a low speed spool30and a high speed spool32mounted for rotation about an engine central longitudinal axis A relative to an engine static structure36via several bearing systems38. It should be understood that various bearing systems38at various locations may alternatively or additionally be provided, and the location of bearing systems38may be varied as appropriate to the application.

The low speed spool30generally includes an inner shaft40that interconnects, a first (or low) pressure compressor44and a first (or low) pressure turbine46. The inner shaft40is connected to a fan section22through a speed change mechanism, which in exemplary gas turbine engine20is illustrated as the fan drive gear system48to drive the fan section22at a lower speed than the low speed spool30. The high speed spool32includes an outer shaft50that interconnects a second (or high) pressure compressor52and a second (or high) pressure turbine54. The low pressure turbine46includes a plurality of turbine rotors34. A combustor56is arranged in exemplary gas turbine20between the high pressure compressor52and the high pressure turbine54. A mid-turbine frame58of the engine static structure36may be arranged generally between the high pressure turbine54and the low pressure turbine46. The mid-turbine frame58further supports bearing systems38in the turbine section28. The inner shaft40and the outer shaft50are concentric and rotate via bearing systems38about the engine central longitudinal axis A which is collinear with their longitudinal axes.

The core airflow is compressed by the low pressure compressor44then the high pressure compressor52, mixed and burned with fuel in the combustor56, then expanded over the high pressure turbine54and low pressure turbine46. The mid-turbine frame58includes airfoils60which are in the core airflow path C. The turbines46,54rotationally drive the respective low speed spool30and high speed spool32in response to the expansion. It will be appreciated that each of the positions of the fan section22, compressor section24, combustor section26, turbine section28, and fan drive gear system48may be varied. For example, the fan drive gear system48may be located aft of the low pressure compressor44, or aft of the combustor section26or even aft of turbine section28, and fan section22may be positioned forward or aft of the fan drive gear system48.

The engine20in one example is a high-bypass geared aircraft engine. the example engine20includes a bypass ratio greater than 20, with an example embodiment being greater than 32 and less than 72. Moreover, although the example turbine engine20is shown with the fan section22disposed within the nacelle18, a turboprop engine is also within contemplation and scope of this disclosure.

The fan drive gear system48is an epicycle gear train with a gear reduction ratio of greater than about 5:1 and less than about 18:1. In another example embodiment, the fan drive gear system48provides a gear reduction ratio of between 8:1 and 13.5:1. The gear system48is coupled to the fan shaft62that is coupled to a hub72supporting a plurality of fan blades42. The gear system48drives the fan blades42about the engine axis A. It should be understood, however, that the above parameters are only exemplary of one embodiment of a geared engine architecture and that the present disclosure is applicable to other gas turbine engine architectures including turbofan, turboshaft, and open rotor engines.

The example engine20includes a lubrication system70with a main lubrication system64and an auxiliary lubrication system66. The auxiliary lubrication system66includes a reservoir68that receives lubricant expelled74from the fan drive gear system48. Lubricant from the auxiliary lubrication system66may be fed back to the main lubrication system and/or fed back to the gear system48.

Referring toFIG.2with continued reference toFIG.1, the example fan drive gear system48is an epicyclic gear system with a sun gear78coupled to a portion of the low shaft40and engaged to a plurality of intermediate gears80supported on a corresponding journal bearing86within a rotating carrier82. A ring gear84circumscribes the intermediate gears80and is fixed to a static engine structure76.

The fan shaft62is coupled to the carrier82and extends radially inward and forward of the gear system48to the fan hub72(FIG.2). Lubricant88is supplied to the gear system48from the main lubrication system64through a transfer bearing90. The carrier82includes a rotating inlet92that extends axially aft. The transfer bearing90is fixed to an engine static structure76and engages the rotating inlet92to communicate oil through passages94. Oil communicated through the rotating inlet92is provided to each gear interface and to the bearing surfaces between the journal bearings86and the intermediate gears80.

Some oil indicated by arrows100leaks through the interface122between the rotating inlet92and the transfer bearing90. A static gutter96is disposed around the transfer bearing90to collect and direct the leakage oil100. The example static gutter96is disposed radially outward of the rotating inlet92and the transfer bearing90. In this example, the rotating inlet92and the transfer bearing90are disposed aft of the gear system48.

A rotating gutter98is attached to an aft portion108of the carrier82and captures oil exhausted through a radial opening124of the static gutter96. The rotating gutter98rotates with the carrier82and imparts rotational momentum into oil exhausted from the static gutter96. Oil within the rotating gutter98is energized and driven radially outward toward an aft auxiliary reservoir102. An oil receiving surface112receives the energized oil indicated by arrows120and communicates it into the auxiliary reservoir102.

A forward auxiliary reservoir104is disposed radially outward and at least partially forward of the gear system48. The forward auxiliary reservoir104includes a forward oil receiving surface114. Oil106expelled from a forward portion110of the carrier82and portions of the gear system48is captured on the oil receiving surface114and communicated into the reservoir104. Oil captured within either of the aft reservoir102and the forward reservoir104may be communicated back into the main lubrication system64or back into the gear system48.

The ring gear84includes passages116for communicating oil into at least one of the forward auxiliary reservoir104and the aft auxiliary reservoir102.

Referring toFIG.3, with continued reference toFIGS.1and2, leakage oil100is captured within the rotating gutter98. Rotation of the gutter98energizes the oil to generate an accelerated oil flow120. The accelerated oil flow120is directed outward through openings126in the rotating gutter98toward the oil receiving surface112. The accelerated oil flow120has a rotational momentum that drives the oil radially outward onto the oil receiving surface112. The oil receiving surface112includes at least one opening128to communicate oil into the auxiliary reservoir102. The example auxiliary reservoir102is shown as a generally annular shape disposed about the rotating gutter98. However, the auxiliary reservoir102may be of other shapes and sizes tailored to application specific space requirements.

An oil guiding feature is provided on the static oil receiving surface112near each opening128. In one disclosed embodiment, the oil guide feature is a scoop118that guides the rotating oil flow through the opening128. The scoop118are shaped and sized to guide rotating oil flow into the auxiliary reservoir102. The rotational momentum imparted by the rotating gutter attached to the carrier82provides for the oil to flow radially outward and into the auxiliary reservoir102. Similarly, the rotational momentum imparted by rotation of the carrier82on the oil106expelled from the gear system provides for the oil to flow into the forward auxiliary reservoir104.

In one example operational embodiment, oil88is communicated to the gear system48through the static transfer bearing90and into the rotating inlet92. Oil is expelled from the gear system and leaks from the interface122at the transfer bearing90. A static baffle surrounds the transfer bearing and directs leaked oil100radially outward and through the radial opening124. Oil exhausted through the radial opening is captured in the rotating gutter98. The rotating gutter98is attached to the aft portion108of the carrier82. Rotation of the gutter98imparts rotational and radially outward directed momentum on the oil. The radially outward momentum propels the oil through openings126(FIG.3) and against the oil receiving surface112. The rotational momentum of the oil drives the accelerated oil flow120circumferentially along the oil receiving surface112. Scoop118of the oil receiving surface112direct oil through opening128into the auxiliary reservoir102. Oil accumulated in the auxiliary reservoir102may be communicated to the main lubrication system64for recirculation and/or routed directly back to the gear system48depending on current operational needs.

Accordingly, the example rotating gutter collects both expelled oil and oil leakage from the transfer bearing and imparts momentum on the captured oil to drive in into an auxiliary reservoir.

Although an example embodiment has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this disclosure. For that reason, the following claims should be studied to determine the scope and content of this disclosure.