Slider seal assembly for gas turbine engine

A slider seal assembly for a gas turbine engine includes a housing, a seal plate moveable relative to the housing and a retaining ring. The housing includes an outer surface, an inner surface, and a recessed opening between the outer surface and the inner surface. The seal plate is received within the recessed opening. The inner surface of the housing includes a curved portion which is curved in an outward direction toward the outer surface.

BACKGROUND OF THE INVENTION

This invention generally relates to a gas turbine engine, and more particularly to a slider seal assembly for a gas turbine engine.

In an aircraft gas turbine engine, such as a turbofan engine, air is pressurized in a compressor and mixed with fuel in a combustor for generating hot combustion gases. The hot combustion gases flow downstream through turbine stages which extract energy from the gases. In a two spool gas turbine engine, a high pressure turbine powers a high pressure compressor, while a low pressure turbine powers a fan section disposed upstream of the compressor and a low pressure compressor.

Combustion gases are discharged from the turbofan engine through a core exhaust nozzle and fan air is discharged through an annular fan exhaust nozzle defined at least partially by a nacelle surrounding the core engine. A majority of propulsion thrust is provided by the pressurized fan air which is discharged through the fan exhaust nozzle, while the remaining thrust is provided from the combustion gases discharged through the core exhaust nozzle.

The core engine components, including the compressor, the combustor and the turbine, are surrounded by a cylindrical outer casing. A multitude of interface parts, such as borescope plugs, are received within openings of the outer casing and provide access points for inspecting the internal components of the core engine. The interface parts are removable to access the interior of the core engine. For example, fiber optics equipment may be inserted into an opening of the outer casing upon removal of a borescope plug to detect debris, cracking or other damage to the interior components of the gas turbine engine.

Additionally, gas turbines engines may include numerous other interface parts, such as fuel fittings, customer bleed ports and the like. Seal assemblies are required to seal the interface between the interface parts and the openings of the outer casing. That is, the seal assemblies reduce airflow leakage between the interface parts and the outer casing as airflow is communicated within the core engine during engine operation.

The seal assemblies typically include a housing and a metallic seal plate, such as a titanium seal plate. The housing is mounted to the outer casing, the seal plate is affixed adjacent to the housing, and the interface part extends through openings of the seal plate and the housing to provide a seal therebetween. The opening of the seal plate must be machined or drilled at an angle to compensate for the curvature of the outer casing.

Disadvantageously, interface parts may experience heavy wear near the contact area between the interface part and the seal plate due to the metallic nature of the seal plate and the angle at which the interface parts extend through the seal plate. The heavy wear at this contact area may result in airflow leakage between the core airflow passage and the fan bypass airflow passage of the gas turbine engine. Increased wear at the interface between the seal assemblies and the interface parts may be furthered by thermal growth mismatch. This is caused by the severe temperature differences the engine experiences between the core airflow passage and the fan bypass airflow passage, which may cause displacement of the interface parts relative to the seal plates.

Accordingly, it is desirable to provide an effective slider seal assembly that reduces wear and reduces airflow leakage between the core airflow passage and the fan bypass airflow passage of a gas turbine engine.

SUMMARY OF THE INVENTION

A slider seal assembly for a gas turbine engine includes a housing, a seal plate moveable relative to the housing and a retaining ring. The housing includes an outer surface, an inner surface, and a recessed opening between the outer surface and the inner surface. The seal plate is received within the recessed opening. The inner surface of the housing includes a curved portion curved in an outward direction toward the outer surface

A slider seal assembly for a gas turbine engine includes a housing and a seal plate which is moveable relative to the housing. The housing includes an outer surface, an inner surface, a body portion extending between the inner surface and the outer surface, and an opening through the housing. The seal plate is received within a recessed opening of the body portion of the housing. The seal plate includes an opening and is positioned adjacent to the opening of the housing. An interface part extends through both the opening of the housing and the opening of the seal plate.

A gas turbine engine system includes an outer engine casing, a compressor, a combustor and a turbine housed within the outer engine casing, and a plurality of slider seal assemblies mounted to the outer engine casing. A portion of an inner surface of each of the plurality of the slider seal assemblies is curved to match a contour of the outer engine casing.

The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1illustrates a gas turbine engine10which includes (in serial flow communication) a fan section12, a low pressure compressor14, a high pressure compressor16, a combustor18, a high pressure turbine20, and a low pressure turbine22. During operation, air is pulled into the gas turbine engine10by the fan section12, pressurized in the compressors14,16, and is mixed with fuel and burned in the combustor18. Hot combustion gases generated within the combustor18flow through the high and low pressure turbines20,22, which extract energy from the hot combustion gases. In a two spool design, the high pressure turbine20powers the high pressure compressor16through a high speed shaft19and the low pressure turbine22powers the fan section12and a low pressure compressor14through a low speed shaft21. However, the invention is not limited to the two spool gas turbine architecture described and may be used with other architectures such as a single spool axial design, a three spool axial design and other architectures. That is, the present invention is applicable to any gas turbine engine.

A nacelle29is disposed circumferentially about an engine centerline axis A and surrounds the numerous components of the gas turbine engine10. A fan bypass passage31extends between an inner surface23of the nacelle29and an outer engine casing58, which houses the compressor sections14,16, the combustor18and the turbine sections20,22. A portion F2of incoming airflow enters the gas turbine engine10and is communicated through a core airflow passage33, while the remaining portion Fl of incoming airflow is communicated through the fan bypass passage31to provide additional thrust for powering the aircraft.

FIGS. 2-5illustrate an example slider seal assembly30. The slider seal assembly30includes a housing32, a seal plate34, and a retaining ring36. The housing32includes a recessed opening38for receiving the seal plate34. The retaining ring36is received within a slot40(SeeFIG. 4) of the recessed opening38to retain the seal plate34within the recessed opening38.

The housing32includes an outer surface42and an inner surface44. The recessed opening38extends circumferentially from the inner surface44in an outward direction towards the outer surface42. A body portion46of the housing32generally surrounds the recessed opening38and at least partially houses the seal plate34within the recessed opening38. An opening48having a diameter D1extends through the housing32and receives an interface part56, as is further discussed below with respect toFIG. 6. The opening48opens into the recessed opening38. The recessed opening38includes a diameter which is larger than the diameter D1.

The inner surface44of the housing32includes a curved portion45. The curved portion45is curved in a direction towards the outer surface42. That is, the curved portion45extends in an outward direction from the inner surface44. It should be understood that the actual dimensions of the curved portion45will vary depending upon design specific parameters including, but not limited to, the size of the outer engine casing58.

The housing32also includes flanges47disposed radially outwardly from the body portion46. The flanges47are disposed near opposite ends of the housing32and each include an opening49for receiving a fastener to attach the slider seal assemblies30to the outer engine casing58of the gas turbine engine10. Each flange47is generally illustrated as triangular is shape, although other shapes are contemplated as would be recognized by a person of ordinary skill in the art having the benefit of this disclosure to attach the slider seal assemblies30to the outer engine casing58.

The seal plate34is received against an inner wall50of the recessed opening38. The inner wall50is the inner surface of the outer surface42of the housing32. The seal plate34also includes an opening52. The opening52is positioned adjacent the opening48of the housing32when received within the recessed opening38, and includes a diameter D2. The diameter D2of the opening52is generally smaller than the diameter D2of the opening48. The seal plate34slides relative to the housing32to compensate for movement of the interface part56(SeeFIG. 6).

The retaining ring36includes a plurality of tabs54. The tabs54allow movement of the seal plate34in axial directions X and Y relative to the housing32while maintaining the seal plate34adjacent to the inner wall50of the housing32(SeeFIG. 3). A person of ordinary skill in the art would understand how to design the retaining ring36to retain the seal plate34within the recessed opening38.

Referring toFIG. 6, an interface part56extends from the gas turbine engine10through the openings48,52of the housing32and seal plate34of the slider seal assembly30. In one example, the interface part56is a borescope plug. A gas turbine engine10may include multiple borescope plugs. The borescope plugs are removable for inspection of the internal components of the gas turbine engine10, such as with fiber optics equipment.

For example, the fiber optics equipment may be used to inspect for debris, cracking or other damage to the internal components of the compressor sections14,16, the combustor18, or the turbine sections20,22of the gas turbine engine10. In another example, the interface part56is a fuel fitting. In yet another example, the interface part56is a customer bleed port. It should be understood that the interface part56may include any part of the gas turbine engine10which may experience displacement as a result of thermal growth mismatch.

The slider seal assembly30seals the gas turbine engine10at the interface part56. A seal is necessitated by providing an opening in the gas turbine engine10for receiving the interface part56. During normal gas turbine engine10operation, there is typically a temperature difference between the airflow F2within the core airflow passage33and the airflow Fl within the fan bypass passage31(SeeFIG. 8). The temperature difference may cause thermal growth mismatch between the core airflow passage33and the fan bypass passage31. That is, the gas turbine engine10may expand and retract in both the radial and axial directions relative to the engine centerline axis A because of the extreme temperature differences. The thermal growth mismatch may result in displacement of the interface part56. The slider seal assembly30is designed to compensate for the thermal growth mismatch and provide lubrication at wear surfaces W as the interface part56travels during the thermal growth mismatch. The wear surfaces W represent the wear areas that result from the interface parts56rubbing against the seal plate34and the housing32during thermal growth mismatch.

The interface part56extends through the opening48of the housing32in a direction normal to the outer surface42. Because the seal plate34is slideable relative to the housing32, the interface part56extends in a direction normal to the outer surface42during engine operation, and maintains the perpendicular positioning during any thermal growth mismatch. That is, the seal plate34slides in the axial directions X and Y (SeeFIG. 3) in response to any expansion/retraction by the gas turbine engine10. As stated above, the diameter D1of the opening48of the housing32is larger than the diameter D2of the opening52of the seal plate34. Therefore, the interface part56has enough clearance space to avoid contact with the housing32during displacement caused by thermal growth mismatch. The slider seal assembly30therefore reduces rubbing at the wear surfaces W, reduces the amount of corner scraping between the seal plate34and the interface part56, and improves leakage performance of the gas turbine engine10.

The seal plate34includes a fiber reinforced composite. The composite material further reduces contact between the interface part56and the wear surfaces W of the seal plate34and the housing32. In one example, the fiber reinforced composite is NR150. In another example, the composite includes PMR15. It should be understood that the seal plate34may be comprised of any other composite type material, including any known polyimide composite material.

FIG. 7illustrates an example gas turbine engine10including a plurality of slider seal assemblies30. The slider seal assemblies30are mounted to the outer engine casing58of the gas turbine engine10. Multiple slider seal assemblies30may be mounted adjacent to the compressor sections14,16, the combustor18, the turbine sections20,22or any other section of the gas turbine engine10. The curved portion45of the inner surface44of each housing32(SeeFIG. 4) includes a curvature which matches the outer contour of the outer engine casing58. The curved portion45of the inner surface44provides an improved interface between the slider seal assemblies30and the outer engine casing58, thereby reducing airflow leakage.

FIG. 8illustrates one example mounting location for the slider seal assemblies30. In this example, several slider seal assemblies30are mounted adjacent to the high pressure compressor16of the gas turbine engine. Interface parts56extends through the outer engine casing58, through the openings52of each seal plate34, and through the openings48of each housing32of each slider seal assembly30. The interface parts56extend in a direction normal to the outer surface42of each housing32. Therefore, during displacement of the interface parts56caused by thermal growth mismatch between the core passage33and the fan bypass passage31, the friction load on the interface part56is reduced and wear is reduced at the wear surfaces W (SeeFIG. 5). The slider seal assemblies30provide adequate sealing between the interface parts56and the gas turbine engine10, which provides improved efficiency of the gas turbine engine10.

The foregoing description shall be interpreted as illustrative and not in any limiting sense. A worker of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. For that reason, the follow claims should be studied to determine the true scope and content of this invention.