Patent Description:
Generally, gas turbine engines include a fan that directs air towards a bypass duct and an engine core of the gas turbine engine. The fan includes a number of blades that are subjected to large amounts of centrifugal forces. During an operation of the gas turbine engine, a root area and an annulus area of each blade may be subjected to high amounts of wear. Thus, each blade typically includes wear resistant strips, such as a Vespel® strip manufactured by DuPont™, attached proximal to the root area and the annulus area via a film adhesive so as to mitigate the wear of the blade, thereby protecting the blade.

Conventionally, an outer surface of the wear resistant strips may be activated by means of a dry grit blast process to expose embedded polytetrafluoroethylene (PTFE) fibres in the wear resistant strip. The blade along with the wear resistant strips and the film adhesives are then cured under vacuum conditions, for example, in an autoclave. Further, curing of the film adhesive in the autoclave may incur high manufacturing costs, as high amounts of energy may be consumed during heating of the entire blade. Conventional methods of joining the wear resistant strip to the blade may cause the adhesive to have a non-uniform bond thickness between the wear resistant strip and the blade. In some conventional methods, oversized wear resistant strips are attached to the blade, and edges of the oversized wear resistant strips are later machined to meet tight tolerances. Such a machining operation may induce damage to the blade, which may in turn lead to delamination and in-service part repairs of the blade, thereby increasing manufacturing costs as well as maintenance costs associated with the blade.

Thus, conventional techniques of coupling the wear resistant strip with the blade may be costly, may affect a quality of the blade, and may cause non-compliance with design requirements of the blade.

International patent application <CIT> discloses a fixing apparatus for fixing a secondary component to a fan blade. The fixing apparatus has a first clamp part that has a first inner surface and a second clamp part that has a second inner surface. The first inner surface and the second inner surface each have a profile that corresponds to a profile of a portion of the fan blade. The first clamp part and/or the second clamp part has a recess in the respective first inner surface and/or second inner surface for receiving the secondary component, and a corresponding heater for applying heat to the secondary component located in the recess in use. The first clamp part and the second clamp part are configured to cooperate with one another to clamp the portion of a blade between them in a clamping operation and to hold the secondary component against the blade when the secondary component is received within the recess.

<CIT> discloses a tooling for fastening metal reinforcement on the leading edge of a turbine engine blade. The tooling has a blade support for receiving a blade while leaving surfaces of the leading edge of the blade disengaged; and a leading edge reinforcement support on which the blade support is designed to be mounted, and includes two lateral wedges between which the metal reinforcement for the leading edge of the blade is positioned. The wedges can moving towards each other and apart from each other and each of them has a suction grid for gripping the metal reinforcement. The leading edge reinforcement support also has heater elements for polymerizing an adhesive film applied on the leading edge surfaces of the blade.

French patent application <CIT> discloses a device for attaching a wear strip to at least one contact face of a turbo engine rotor blade. The device has heat-generating means for activating a product for attaching the wear strip to the blade. The heat-generating means are designed to generate heat only on the wear strip and on the at least one contact face of the blade.

In a first aspect, there is provided a system for coupling at least one component to a blade of a gas turbine engine as set out in claim <NUM>.

The system of the present invention may provide a cost-effective approach to couple the at least one component to the blade. Specifically, the system uses the heating device to cure the adhesive layer in order to couple the at least one component to the blade. Thus, the heating device may eliminate the requirement of heating the entire blade to cure the adhesive layer (for example, in an autoclave), which may save manufacturing costs. Further, the system may provide faster curing cycles as only a portion of the blade is heated for curing the adhesive layer.

Further, as the pressure strip fully encloses the plate, the pressure strip may allow uniform distribution of the pressure (that is being applied by the pressure applicator) along a length of the plate. The pressure strip of the system may provide spew control, thereby providing the uniform bond thickness of the adhesive layer and minimal to no voids between the at least one component and the blade. As the voids are minimal, an adhesion between the at least one component and the blade may be improved, while also improving in-service life and functionality of the at least one component. Further, the system may eliminate any additional steps of machining the at least one component, thereby maintaining the structural integrity of the at least one component as well as the blade. Furthermore, the at least one component may be of high quality and may be compliant with profile tolerances, surface tolerances, adhesive thickness, and porosity requirements.

Further, the system described herein may be used as an on-site as well an off-site repair solution during servicing of the blades. Furthermore, the system may be portable and easy to use by operators for repair and maintenance of blades.

In some embodiments, the at least one component includes a polyimide-based wear resistant strip, e.g. a Vespel® wear resistant polyimide-based plastic strip manufactured by DuPont™. It should be noted that the strip may demonstrate properties, such as, heat resistance, lubricity, dimensional stability, chemical resistance, wear resistance, and creep resistance. Therefore, the strip may allow the blade to be used in hostile and extreme operating conditions, while preventing damage to the blade. Alternatively, the system described herein may be used to couple any other component to a portion of the gas turbine engine.

In some embodiments, the at least one component is made of a material that exhibits a coefficient of friction below <NUM>, high load resistance, high temperature resistance, corrosion resistance, and/or wear resistance. Thus, the at least one component may allow the blade to be used in hostile and extreme operating conditions, while preventing damage to the blade.

In some embodiments, the pressure strip includes at least one of a butyl rubber, a platinum cured rubber, a silicone based rubber, and a peroxide cured rubber. The pressure strip made of one of the above listed rubbers may completely enclose the plate of the intensifier tool so as to prevent a flow-out of the adhesive layer. This may result in the uniform bond thickness and minimal to no voids in the adhesive layer, thereby improving adhesion between the at least one component and the blade, as well as improving in-service life and functionality of the at least one component.

In some embodiments, the system further includes an insulation layer disposed on the blade. The insulation layer is further at least partially disposed on the pressure strip. The insulation layer may cover the blade to minimize heat dissipation and may retain different curing temperatures localized at a root area and/or an annulus area of the blade. The insulation layer may prevent any damage to the blade due to overheating.

In some embodiments, the at least one component includes a plurality of first components configured to be coupled to the root area of the blade and a pair of second components configured to be coupled to the annulus area of the blade. The plurality of first components and the pair of second components may serve as sacrificial components to protect the blade from wear and damage.

In some embodiments, the system further includes at least one first temperature sensor configured to measure a first temperature proximal to the root area of the blade and at least one second temperature sensor configured to measure a second temperature proximal to the annulus area of the blade. The at least one first temperature sensor is disposed proximal to the root area and the at least one second temperature sensor is disposed proximal to the annulus area.

The first temperature sensor and the second temperature sensor may measure the first and second temperatures proximal to the root area and the annulus area of the blade, respectively, so as to ensure that the first and second temperatures are sufficient to facilitate curing of the adhesive layer, without causing any damage to the at least one component, the blade, and/or the adhesive layer. Based on values of the first and second temperatures received from the first and second temperature sensors, the heating devices, that is used to cure the adhesive layers associated with the first and second components, may be operated so as to maintain different first and second temperatures at the root area and the annulus area. Thus, the heating device together with the first and second temperature sensors may allow multi-zone temperature curing of the adhesive layer near the root area of the blade and the annulus area of the blade.

In some embodiments, the plate of the intensifier tool includes at least one of a carbon material and a metallic material. The plate of the intensifier tool may be cost-effective and portable and may also facilitate incorporation of the heating device.

In some embodiments, the heating device is at least partially embedded within the plate of the intensifier tool. The heating device may cure the adhesive layer to couple the at least one component to the blade. Such a heating device may provide a stand-alone curing solution, thereby eliminating use of the autoclave to cure the adhesive layer to couple the at least one component to the blade. Further, the heating device may provide a portable solution for service and maintenance of the blade. The heating device may heat only the desired area of the blade instead of heating the entire blade, thereby preventing high energy consumption.

In some embodiments, the heating device includes at least one of an electric cartridge, a heated fabric, and a heated film. Such a heating device may provide a stand-alone curing solution, thereby eliminating use of the autoclave to cure the adhesive layer to couple the at least one component to the blade. Further, the heating device may provide a portable solution for service and maintenance of the blade. The heating device may heat only the desired area of the blade instead of heating the entire blade, thereby preventing high energy consumption.

In some embodiments, the heating device includes at least one of a ceramic heater, an induction heater, and a heated fluid. Such a heating device may provide a stand-alone curing solution, thereby eliminating use of the autoclave to cure the adhesive layer to couple the at least one component to the blade. Further, the heating device may provide a portable solution for service and maintenance of the blade. The heating device may heat only the desired area of the blade instead of heating the entire blade, thereby preventing high energy consumption.

In some embodiments, the pressure applicator includes one or more clamps configured to apply the pressure on the plate. The one or more clamps may ensure uniform application of pressure on the plate so that the at least one component may adhere to the blade in a desired manner, while maintaining the uniform bond thickness.

In a second aspect, there is provided a method of coupling at least one component to a blade of a gas turbine engine as set out in claim <NUM>.

The method of the present invention may provide a cost saving approach to couple the at least one component to the blade. The method teaches use of the heating device to cure the adhesive layer in order to couple the at least one component to the blade. Thus, the method may eliminate the requirement of heating the entire blade to cure the adhesive layer (for example, in the autoclave), which may save manufacturing costs. Further, the method may provide faster curing cycles as only some portion of the blade is heated for curing the adhesive layer.

Further, the method also teaches use of pressure strip that may provide spew control, thereby providing the uniform bond thickness of the adhesive layer and minimal to no voids between the at least one component and the blade. As the voids are minimal, an adhesion between the at least one component and the blade may be improved. Further, the method may eliminate any additional steps of machining the at least one component, thereby maintaining the structural integrity of the at least one component as well as the blade. Furthermore, the at least one component may be of high quality and may be compliant with profile tolerances, surface tolerances, adhesive thickness, and porosity requirements.

Further, the method described herein may be used as on-site as well an off-site repair solution during servicing of the blades. Furthermore, the method may provide operators a portable and easy-to-use solution for repair and maintenance of blades.

In some embodiments, the method further includes disposing an insulation layer on the blade after coupling the pressure strip to the plate of the intensifier tool and the blade. The insulation layer may cover the blade to minimize heat dissipation and may retain the different curing temperatures localized at a root area and/or an annulus area of the blade. The insulation layer may prevent damage to the blade due to overheating.

In some embodiments, the at least one component includes a plurality of first components configured to be coupled proximal to a root area of the blade and a pair of second components configured to be coupled proximal to an annulus area of the blade. The plurality of first components and the pair of second components may serve as sacrificial components to protect the blade from wear and damage.

In some embodiments, the method further includes measuring, via at least one first temperature sensor disposed proximal to the root area, a first temperature proximal to the root area of the blade. The method further includes controlling a first temperature proximal to the root area of the blade, such that the first temperature corresponds to a first predetermined temperature value.

The first temperature sensor may measure the first temperature proximal to the root area so as to ensure that the first temperature proximal to the root area is sufficient to facilitate curing of the adhesive layer, without causing any damage to the plurality of first components, the root area, and/or the adhesive layer. Based on the value of the first temperature received from the first temperature sensor, the heating device, that is used to cure the adhesive layers associated with the plurality of first components, may be operated so as to maintain the first temperature at the root area.

In some embodiments, the method further includes measuring, via at least one second temperature sensor disposed proximal to the annulus area, a second temperature proximal to the annulus area of the blade. The method further incudes controlling the second temperature proximal to the annulus area of the blade, such that the second temperature corresponds to a second predetermined temperature value.

The second temperature sensor may measure the second temperature proximal to the annulus area of the blade so as to ensure that the second temperature proximal to the annulus area is sufficient to facilitate curing of the adhesive layer, without causing any damage to the pair of second components, the annulus area, and/or the adhesive layer. Based on the value of the second temperature, the heating device, that is used to cure the adhesive layers associated with the pair of second components, may be operated so as to maintain the second temperature at the annulus area. Thus, the heating device together with the second temperature sensor may allow multi-zone temperature curing of the adhesive layer near the annulus area of the blade.

In some embodiments, the pressure applicator includes one or more clamps. The method further includes applying the pressure on the plate via the one or more clamps. The one or more clamps may ensure proper application of pressure on the plate such that the at least one component may properly adhere to the blade, while maintaining the uniform bond thickness.

As used herein, the term "configured to" and like is at least as restrictive as the term "adapted to" and requires actual design intention to perform the specified function rather than mere physical capability of performing such a function.

As used herein, the terms "first", "second", and "third" are used as identifiers. Therefore, such terms should not be construed as limiting of this invention. The terms "first", "second" and "third", when used in conjunction with a feature or an element can be interchanged throughout the embodiments of this invention.

As used herein, "at least one of A and B" should be understood to mean "only A, only B, or both A and B".

As used herein, the term "partially" refers to any percentage greater than <NUM>%. In other words, the term "partially" refers to any amount of a whole. For example, "partially" may refer to a small portion, half, or a selected portion of a whole. In some cases, "partially" may refer to a whole amount. The term "partially" refers to any percentage less than <NUM>%.

<FIG> illustrates a schematic side view of a gas turbine engine <NUM> having a principal rotational axis <NUM>. The gas turbine engine <NUM> comprises an air intake <NUM> and a propulsive fan <NUM> that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine <NUM> comprises an engine core <NUM> that receives the core airflow A. In other words, the core airflow A enters the engine core <NUM>. The fan <NUM> is located upstream of the engine core <NUM>. The fan <NUM> includes a plurality of blades <NUM> (only one is shown herein for illustrative purposes) that upon rotating, generates the core airflow A and the bypass airflow B. The engine core <NUM> comprises, in axial flow series, a compressor, a combustor, and a turbine. Specifically, the engine core <NUM> comprises, in axial flow series, a low pressure compressor <NUM>, a high pressure compressor <NUM>, a combustor <NUM>, a high pressure turbine <NUM>, a low pressure turbine <NUM>, and a core exhaust nozzle <NUM>. The bypass airflow B flows through the bypass duct <NUM> surrounding the engine core <NUM>. The bypass airflow B flows through the bypass duct <NUM> to provide propulsive thrust, where it is straightened by a row of outer guide vanes <NUM> before exiting the bypass exhaust nozzle <NUM>. The outer guide vanes <NUM> extend radially outwardly from an inner ring <NUM> which defines a radially inner surface of the bypass duct <NUM>. Rearward of the outer guide vanes <NUM>, the engine core <NUM> is surrounded by an inner cowl <NUM> which provides an aerodynamic fairing defining an inner surface of the bypass duct <NUM>. The inner cowl <NUM> is rearwards of and axially spaced from the inner ring <NUM>. A fan case <NUM> defines an outer surface of the bypass duct <NUM>. The inner ring <NUM> defines the inner surface of the bypass duct <NUM> towards the rear of the fan case <NUM>.

The compressed air exhausted from the high pressure compressor <NUM> is directed into the combustor <NUM> where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high pressure and low pressure turbines <NUM>, <NUM> before being exhausted through the core exhaust nozzle <NUM> to provide some propulsive thrust. A core shaft <NUM> connects the turbine <NUM>, <NUM> to the compressor <NUM>, <NUM>. Specifically, the high pressure turbine <NUM> drives the high pressure compressor <NUM> by the suitable core shaft <NUM> or an interconnecting shaft.

<FIG> is a schematic perspective view of a portion of the blade <NUM> associated with the fan <NUM> shown in <FIG>, according to an embodiment of the present invention. Although only the single blade <NUM> is being explained in detail, the details provided herein are equally applicable to all blades <NUM> of the fan <NUM>, without any limitations. The blade <NUM> includes an annulus area <NUM> and a root area <NUM>. The annulus area <NUM> extends from the root area <NUM>. It should be noted that the root area <NUM> of the blade <NUM> may include a dovetail root, a firtree root, or other type of root. In the illustrated embodiment of <FIG>, the root area <NUM> of the blade <NUM> includes the dovetail root.

The present invention is directed towards coupling of at least one component <NUM>, <NUM> with the blade <NUM>. Specifically, the at least one component <NUM>, <NUM> includes a plurality of first components <NUM> configured to be coupled to the root area <NUM> of the blade <NUM> and a pair of second components <NUM> configured to be coupled to the annulus area <NUM> of the blade <NUM>.

The plurality of first components <NUM> includes four first components <NUM> that are coupled to the root area <NUM> at each side of the blade <NUM>. Particularly, the plurality of first components <NUM> includes a first pair of the first components <NUM> coupled to the root area <NUM> of the blade <NUM> disposed opposite to each other and a second pair of the first components <NUM> configured to be coupled to corresponding flanks <NUM> (only one of which is shown herein) of the root area <NUM> of the blade <NUM>. Further, each of the first pair of the first components <NUM> is rectangular in shape and corresponds to a shape of the root area <NUM> at which the first component <NUM> is to be coupled. As shown in <FIG>, each of the second pair of first components <NUM> is rectangular in shape. Further, each of the second pair of the first components <NUM> is rectangular in shape. In other examples, the second pair of first components <NUM> may have any other shape. Furthermore, the pair of second components <NUM> may have a curved shape similar to a shape of the annulus area <NUM> of the blade <NUM>. Each of the first components <NUM> and the second components <NUM> are embodied as strips herein.

The plurality of first components <NUM> and the pair of second components <NUM> may serve as sacrificial components to protect the blade <NUM> from wear and damage. Specifically, since the blade <NUM> may experience centrifugal forces during an operation of the gas turbine engine <NUM>, the plurality of first components <NUM> and the pair of second components <NUM> may prevent the blade <NUM> from wear and damage. In some embodiments, the at least one component <NUM>, <NUM> includes a polyimide-based wear resistant strip. , e.g. a Vespel® strip manufactured by DuPont™, and may demonstrate properties, such as, heat resistance, lubricity, dimensional stability, chemical resistance, wear resistance, and creep resistance. Therefore, the strip may allow the blade <NUM> to be used in hostile and extreme operating conditions, while preventing damage to the blade <NUM>.

In other embodiments, the at least one component <NUM>, <NUM> may be made of any other material. For example, in some embodiments, the at least one component <NUM>, <NUM> is made of a material that exhibits a coefficient of friction below <NUM>, high load resistance, high temperature resistance, corrosion resistance, and/or wear resistance. Thus, the at least one component <NUM>, <NUM> may allow the blade <NUM> to be used in hostile and extreme operating conditions, while preventing damage to the blade <NUM>. In some examples, the at least one component <NUM>, <NUM> may be made of any fiber reinforced plastic. Further, the material of the at least one component <NUM>, <NUM> may have a lower hardness than the material of the blade <NUM> such that the at least one component <NUM>, <NUM> acts as a sacrificial component and wears in use to protect the blade <NUM>.

<FIG> is a schematic perspective of a system <NUM> for coupling the at least one component <NUM>, <NUM> to the blade <NUM> of the gas turbine engine <NUM> of <FIG>. The system <NUM> includes a blade holder <NUM>. The blade holder <NUM> holds the blade <NUM> in a stationary condition during the coupling of the at least one component <NUM>, <NUM> with the blade <NUM>. The blade holder <NUM> includes a plurality of side walls <NUM>. In the illustrated embodiment of <FIG>, the blade holder <NUM> includes four side walls <NUM>.

The blade holder <NUM> further includes a bottom wall <NUM> connected to each of the plurality of side walls <NUM>. The bottom wall <NUM> and the plurality of side walls <NUM> together define a receiving space <NUM> to receive at least a portion <NUM> of the blade <NUM> and the at least one component <NUM> therein. As is apparent from <FIG>, the receiving space <NUM> receives the root area <NUM> of the blade <NUM> and the plurality of first component <NUM> therein. Further, the blade holder <NUM> may be similar in shape to the root area <NUM> of the blade <NUM>, so that the root area <NUM> of the blade <NUM> is receivable within the blade holder <NUM>.

The system <NUM> further includes an intensifier tool <NUM> disposed on the at least one component <NUM>, <NUM>. Specifically, one intensifier tool <NUM> is disposed on each component <NUM>, <NUM> to facilitate coupling of the corresponding component <NUM>, <NUM> with the blade <NUM>. The intensifier tool <NUM> coupled to the corresponding components <NUM>, <NUM> are similar in terms of functionality and arrangement of devices, however, a shape and a size of the intensifier tool <NUM> may vary as per a shape and a size of the component <NUM>, <NUM>.

<FIG> is a schematic cross-sectional view illustrating the intensifier tool <NUM>. The intensifier tool <NUM> includes a plate <NUM> configured to contact the at least one component <NUM>, <NUM>. In some embodiments, the plate <NUM> of the intensifier tool <NUM> includes at least one of a carbon material and a metallic material. It should be noted that a shape and a size of the plate <NUM> is similar to the shape and the size of the components <NUM>, <NUM>. Accordingly, the plate <NUM> may have a rectangular shape or a curved shape as per the shape of the components <NUM>, <NUM>, respectively.

The intensifier tool <NUM> further includes a heating device <NUM> coupled to the plate <NUM> and configured to heat the at least one component <NUM>, <NUM>. In some embodiments, the heating device <NUM> is at least partially embedded within the plate <NUM> of the intensifier tool <NUM>. In some embodiments, the heating device <NUM> includes at least one of an electric cartridge <NUM> (shown in <FIG>), a heated fabric <NUM> (shown in <FIG>), and a heated film <NUM>. In the illustrated embodiment of <FIG>, the heating device <NUM> includes the heated film <NUM> configured to heat the at least one component <NUM>, <NUM>. The heated film <NUM> may be embedded in the plate <NUM>. The heated film <NUM> may heat the plate <NUM> and subsequently the component <NUM>, <NUM> for curing an adhesive layer <NUM>. The heated film <NUM> may be a metallic film.

In some other embodiments, the heating device <NUM> includes at least one of a ceramic heater, an induction heater <NUM> (shown in <FIG>), and a heated fluid <NUM> (shown in <FIG>). In some embodiments, the heating device <NUM> embodied as the ceramic heater (not shown) may be embedded in the plate <NUM>. The ceramic heater may include a plurality of heating elements that may generate heat. Further, a temperature of the ceramic heater may be controlled by changing a voltage or an amperage applied to the heating elements of the ceramic heater.

It should be noted that the plate <NUM> of the intensifier tool <NUM> described herein may be cost-effective and portable, and may also facilitate inclusion of the heating device <NUM>.

Referring to <FIG> and <FIG>, the system <NUM> further includes the adhesive layer <NUM> disposed between the at least one component <NUM>, <NUM> and the blade <NUM>. The adhesive layer <NUM> bonds the component <NUM>, <NUM> to the blade <NUM> on heating. In some examples, the adhesive layer <NUM> may include a high bonding adhesive. In an example, the adhesive layer <NUM> may include epoxy, without any limitations.

As shown in <FIG>, the system <NUM> includes a pressure strip <NUM>. <FIG> is a schematic cross-sectional view illustrating the pressure strip <NUM> coupled to the intensifier tool <NUM> and the blade <NUM>. <FIG> is a schematic perspective view of the pressure strip <NUM> coupled to the plate <NUM> (see <FIG>) and the blade <NUM>.

Referring to <FIG> and <FIG>, the pressure strip <NUM> fully encloses the plate <NUM>. The pressure strip <NUM> is shown by a hatching in <FIG> to differentiate the pressure strip <NUM> from other parts of the blade <NUM>. In some embodiments, the pressure strip <NUM> includes at least one of a butyl rubber, a platinum cured rubber, a silicone based rubber, and a peroxide cured rubber. The pressure strip <NUM> made of one of the above listed rubbers may completely enclose the plate <NUM> of the intensifier tool <NUM> (see <FIG>) so as to prevent a flow-out of the adhesive layer <NUM>. The pressure strip <NUM> may result in the uniform bond thickness T1 (shown in <FIG>), minimal or no voids in the adhesive layer <NUM>, and improved adhesion between the at least one component <NUM>, <NUM> (see <FIG>) and the blade <NUM>.

As shown in <FIG>, the system <NUM> further includes a pressure applicator <NUM> coupled to the pressure strip <NUM> and configured to apply a pressure on the plate <NUM>. Further, as the pressure strip <NUM> fully encloses the plate <NUM>, the pressure strip <NUM> may allow uniform distribution of the pressure (that is being applied by the pressure applicator <NUM>) along a length of the plate <NUM>. In some embodiments, the pressure applicator <NUM> includes one or more clamps <NUM> configured to apply the pressure on the plate <NUM>. Specifically, the pressure applicator <NUM> includes three clamps <NUM> that are equidistant from each other. Alternatively, the pressure applicator <NUM> may include any number of clamps <NUM> to apply uniform pressure on the plate <NUM>. The clamps <NUM> are configured to hold the components <NUM>, <NUM> received in the receiving space <NUM> of the blade holder <NUM> against the blade <NUM> during a clamping operation. Further, the clamps <NUM> may apply a controlled amount of the pressure on the plate <NUM>. In some examples, the controlled amount of the pressure may be applied via pneumatics or hydraulics. Thus, the the pressure strip <NUM> and the pressure applicator <NUM> may together ensure uniform application of pressure on the plate <NUM> so that the at least one component <NUM>, <NUM> may adhere to the blade <NUM> in a desired manner, while maintaining a uniform bond thickness T1 (shown in <FIG>).

It should be noted that the usage of clamps <NUM> for applying the pressure is exemplary in nature. Accordingly, the pressure applicator <NUM> may include any other component by which the pressure may be applied on the at least one component <NUM>, <NUM>, via the plate <NUM>. In some examples, the pressure applicator <NUM> may include a hydraulic or pneumatic device (such as, cylinder) to apply the pressure on the plate <NUM>.

Referring now to <FIG> and <FIG>, the system <NUM> further includes an insulation layer <NUM> disposed on the blade <NUM>. The insulation layer <NUM> is further at least partially disposed on the pressure strip <NUM>. In other words, the insulation layer <NUM> may be disposed after the pressure strip <NUM> is coupled to the plate <NUM> and the blade <NUM>. Further, the insulation layer <NUM> may be disposed after the pressure applicator <NUM> is coupled to the pressure strip <NUM>. In some examples, the insulation layer <NUM> may include a cut-out/opening to accommodate the pressure applicator <NUM>.

Referring to <FIG>, the insulation layer <NUM> encloses the blade <NUM> from the root area <NUM> up to the annulus area <NUM>. The insulation layer <NUM> may cover the blade <NUM> to minimize heat dissipation and may retain different curing temperatures localized at the root area <NUM> and/or the annulus area <NUM> of the blade <NUM>. The insulation layer <NUM> may prevent any damage to the blade <NUM> due to overheating.

In some embodiments, the system <NUM> further includes at least one first temperature sensor <NUM> configured to measure a first temperature S1 proximal to the root area <NUM> of the blade <NUM> and at least one second temperature sensor <NUM> configured to measure a second temperature S2 proximal to the annulus area <NUM> of the blade <NUM>. Specifically, the first temperature sensor <NUM> measures the first temperature S1 proximal to the root area <NUM> of the blade <NUM>. The at least one first temperature sensor <NUM> may be disposed within the receiving space <NUM> of the blade holder <NUM>. The first temperature S1 is measured so as to ensure that the first temperature S1 corresponds to a first predetermined temperature value V1 that is to be maintained in the root area <NUM>. In some examples, the first temperature S1 may lie in a range of <NUM> to <NUM> degrees.

Further, the second temperature sensor <NUM> measures the second temperature S2 proximal to the annulus area <NUM> of the blade <NUM>. The at least one second temperature sensor <NUM> may be disposed proximal to the annulus area <NUM> and outside of the blade holder <NUM>. The second temperature S2 is measured so as to ensure that the second temperature S2 corresponds to a second predetermined temperature value V2 that is to be maintained in the annulus area <NUM>. The second temperature S2 may lie in a range of <NUM> to <NUM> degrees. In the illustrated embodiment of <FIG>, the single first temperature sensor <NUM> and the single second temperature sensor <NUM> are shown, however, the system <NUM> may include multiple first and second temperature sensors <NUM>, <NUM>.

The first temperature sensor <NUM> and the second temperature sensor <NUM> may measure the first and second temperatures S1, S2 proximal to the root area <NUM> and the annulus area <NUM> of the blade <NUM>, respectively, so as to ensure that the first and second temperatures S1, S2 are sufficient to facilitate curing of the adhesive layer <NUM>, without causing any damage to the at least one component <NUM>, <NUM>, the blade <NUM>, and/or the adhesive layer <NUM>. Based on the values of the first and second temperatures S1, S2 received from the first and second temperature sensors <NUM>, <NUM>, the heating devices <NUM>, that is used to cure the adhesive layers <NUM>, may be operated so as to maintain different first and second temperatures S1, S2 at the root area <NUM> and the annulus area <NUM>. Thus, the heating device <NUM> together with the first and second temperature sensors <NUM>, <NUM> may allow multi-zone temperature curing of the adhesive layer <NUM> near the root area <NUM> of the blade <NUM> and the annulus area <NUM> of the blade <NUM>.

In some embodiments, the system <NUM> may include a controller (not shown) for controlling the heating device <NUM>. The controller may receive values of the first and second temperatures S1, S2 from the first temperature sensor <NUM> and the second temperature sensor <NUM>, respectively. The controller may further control the heating devices <NUM> to ensure that the first and second temperatures S1, S2 proximal to the root area <NUM> and the annulus area <NUM> correspond to the first and second predetermined temperature values V1, V2, respectively. In some examples, the controller may be a control circuit, a computer, a microprocessor, a microcomputer, a central processing unit, or any suitable device or apparatus.

<FIG> is a schematic cross-sectional view illustrating the at least one component <NUM> coupled to the root area <NUM> of the blade <NUM> via the adhesive layer <NUM>. Specifically, upon being heated by the heating device <NUM> (see <FIG>), the adhesive layer <NUM> is cured, thereby coupling the at least one component <NUM> to the blade <NUM>. As can be seen from <FIG>, the adhesive layer <NUM> has the uniform bond thickness T1 along a length L1 of the at least one component <NUM> due to the pressure applied by the pressure applicator <NUM>.

In some examples, the adhesive layer <NUM> may have the uniform bond thickness T1 of greater than <NUM> millimetres (mm). Further, the system <NUM> may ensure substantially a smaller or no void formation between the at least one component <NUM>, <NUM> and the blade <NUM>. For example, the system <NUM> may ensure less than <NUM>% of voids having a size of less than <NUM> between the at least one component <NUM>, <NUM> and the blade <NUM>, thereby improving adhesion between the at least one component <NUM>, <NUM> and the blade <NUM>, as well as improving in-service life and functionality of the component <NUM>, <NUM>.

Referring to <FIG>, the system <NUM> of the present invention may provide a cost-effective approach to couple the at least one component <NUM>, <NUM> to the blade <NUM>. Specifically, the system <NUM> uses the heating device <NUM> to cure the adhesive layer <NUM> in order to couple the at least one component <NUM>, <NUM> to the blade <NUM>. Thus, the heating device <NUM> may eliminate the requirement of heating the entire blade <NUM> to cure the adhesive layer <NUM> (for example, in an autoclave), which may save manufacturing costs. Further, the system <NUM> may provide faster curing cycles as only some portion of the blade <NUM> is heated for curing the adhesive layer <NUM>.

The pressure strip <NUM> of the system <NUM> may provide spew control, thereby providing the uniform bond thickness T1 of the adhesive layer <NUM> and minimal to no voids between the at least one component <NUM>, <NUM> and the blade <NUM>. As the voids are minimal, an adhesion between the at least one component <NUM>, <NUM> and the blade <NUM> may be improved, while also improving in-service life and functionality of the at least one component <NUM>, <NUM>. Further, the system <NUM> may eliminate any additional steps of machining the at least one component <NUM>, <NUM>, thereby maintaining the structural integrity of the at least one component <NUM>, <NUM> as well as the blade <NUM>. Furthermore, the at least one component <NUM>, <NUM> may be of high quality and may be compliant with profile tolerances, surface tolerances, adhesive thickness, and porosity requirements.

Further, the system <NUM> described herein may be used as an -site as well an off-site repair solution during servicing of the blades <NUM>. Furthermore, the system <NUM> may be portable and easy-to-use by operators for repair and maintenance of blades <NUM>. It should be noted that the system <NUM> may be used to couple any other component to the gas turbine engine <NUM>.

<FIG> is a schematic view of the heating device <NUM> of an intensifier tool of an embodiment of the system of the present disclosure. The heating device <NUM> includes the heated fabric <NUM> coupled to the plate <NUM> and configured to cure the adhesive layer <NUM> (see <FIG>). The heated fabric <NUM> may be received within the plate <NUM>. The heated fabric <NUM> may include non-metallic porous or perforated fabric heating elements. In some examples, the heating elements may be in the form of conductive yarns, filaments, fibres, wires, and the like. The heated fabric <NUM> may generate heat when a voltage is applied to the heating elements. The heat generated by the heated fabric <NUM> may cure the adhesive layer <NUM>.

<FIG> is a schematic view of the heating device <NUM> of an intensifier tool of another embodiment of the system of the present invention. The heating device <NUM> includes the electric cartridge <NUM> configured to cure the adhesive layer <NUM> (see <FIG>). The electric cartridge <NUM> may be received within the plate <NUM>. The electric cartridge <NUM> includes a casing <NUM>. The electric cartridge <NUM> further includes one or more first heat pipes <NUM> and one or more second heat pipes <NUM> disposed orthogonal to the one or more first heat pipes <NUM>. Each of the first and second heat pipes <NUM>, <NUM> are disposed within the casing <NUM>. The first and second heat pipes <NUM>, <NUM> may generate heat when a voltage is applied to the first heat pipes <NUM> and/or the second heat pipes <NUM>. The heat generated by the electric cartridge <NUM> may cure the adhesive layer <NUM>.

<FIG> is a schematic view of the heating device <NUM> of an intensifier tool of yet another embodiment of the system of the present invention. The heating device <NUM> includes the induction heater <NUM> configured to cure the adhesive layer <NUM> (see <FIG>). The induction heater <NUM> may be at least partially embedded within the plate <NUM>. The induction heater <NUM> includes an inductor <NUM>. In some examples, the inductor <NUM> may be a copper inductor. In other examples, the inductor <NUM> may be made of any other material configured to conduct heat and electricity. Induction heating may be achieved by applying a high-frequency current to the inductor <NUM>, thereby generating a magnetic field around the inductor <NUM>. The magnetic field induces eddy currents in a circular path in the plate <NUM>, thereby generating heat. The heat generated by the induction heater <NUM> may cure the adhesive layer <NUM>.

<FIG> is a schematic view of the heating device <NUM> of an intensifier tool of a further embodiment of the system of the present invention. The heating device <NUM> includes the heated fluid <NUM> configured to cure the adhesive layer <NUM> (see <FIG>). For example, compressed air may be used as the heated fluid <NUM>. The plate <NUM> may define at least one inlet flow channel <NUM> and at least one outlet flow channel <NUM> separated by the at least one inlet flow channel <NUM> via a divider <NUM>. The heated fluid <NUM> may enter the plate <NUM> via the inlet flow channels <NUM> and exit the plate <NUM> via the outlet flow channels <NUM>. The heated fluid <NUM> may generate heat to cure the adhesive layer <NUM> while flowing through the plate <NUM>. Alternatively, flow conduits may be disposed within the plate <NUM> to define channels through which the heated fluid <NUM> may flow.

<FIG> is a flowchart for a method <NUM> of coupling the at least one component <NUM>, <NUM> to the blade <NUM> of the gas turbine engine <NUM> of <FIG>, according to an embodiment of the present invention. The at least one component <NUM>, <NUM> includes the plurality of first components <NUM> configured to be coupled proximal to the root area <NUM> of the blade <NUM> and the pair of second components <NUM> configured to be coupled proximal to the annulus area <NUM> of the blade <NUM>.

With reference to <FIG>, at step <NUM>, the blade holder <NUM> is provided. The blade holder <NUM> includes the plurality of side walls <NUM> and the bottom wall <NUM> connected to each of the plurality of side walls <NUM>. The bottom wall <NUM> and the plurality of side walls <NUM> together define the receiving space <NUM>.

At step <NUM> the adhesive layer <NUM> is disposed between the at least one component <NUM>, <NUM> and the blade <NUM>. At step <NUM>, the at least one component <NUM>, <NUM> is placed on the blade <NUM>. At step <NUM>, at least a portion <NUM> of the blade <NUM> and the at least one component <NUM>, <NUM> is received within the receiving space <NUM> of the blade holder <NUM>.

At step <NUM>, the intensifier tool <NUM> is placed on the least one component <NUM>, <NUM>. The intensifier tool <NUM> includes the plate <NUM> configured to contact the at least one component <NUM>, <NUM> and the heating device <NUM> coupled to the plate <NUM>.

At step <NUM>, the pressure strip <NUM> is coupled to the plate <NUM> of the intensifier tool <NUM> and the blade <NUM>. The pressure strip <NUM> fully encloses the plate <NUM>. The method <NUM> further includes disposing the insulation layer <NUM> on the blade <NUM> after coupling the pressure strip <NUM> to the plate <NUM> of the intensifier tool <NUM> and the blade <NUM>.

At step <NUM>, the pressure applicator <NUM> is coupled to the pressure strip <NUM>.

At step <NUM>, the pressure applicator <NUM> applies the pressure on the plate <NUM> of the intensifier tool <NUM>. In some embodiments, the pressure applicator <NUM> includes the one or more clamps <NUM>. The method <NUM> further includes a step at which the one or more clamps <NUM> apply the pressure on the plate <NUM>.

At step <NUM>, the pressure applied by the pressure applicator <NUM> provides the uniform bond thickness T1 of the adhesive layer <NUM> along the length L1 of the at least one component <NUM>, <NUM>.

At step <NUM>, the at least one component <NUM>, <NUM> is heated via the heating device <NUM> to cure the adhesive layer <NUM>, thereby coupling the at least one component <NUM>, <NUM> to the blade <NUM>.

The method <NUM> further includes a step of measuring, via the at least one first temperature sensor <NUM> disposed proximal to the root area <NUM>, the first temperature S1 proximal to the root area <NUM> of the blade <NUM>. The method <NUM> further includes a step of controlling the first temperature S1 proximal to the root area <NUM> of the blade <NUM>, such that the first temperature S1 corresponds to the first predetermined temperature value V1.

The method <NUM> further includes a step of measuring, via at least one second temperature sensor <NUM> disposed proximal to the annulus area <NUM>, the second temperature S2 proximal to the annulus area <NUM> of the blade <NUM>. The method <NUM> further includes a step of controlling the second temperature S2 proximal to the annulus area <NUM> of the blade <NUM>, such that the second temperature S2 corresponds to the second predetermined temperature value V2.

It should be noted that, during actual implementation, an order in which the steps of the method <NUM> are performed may vary from what is explained above and illustrated in <FIG>, as per requirements.

Claim 1:
A system (<NUM>) for coupling at least one component (<NUM>, <NUM>) to a blade (<NUM>) of a gas turbine engine (<NUM>), the system (<NUM>) comprising:
a blade holder (<NUM>) including a plurality of side walls (<NUM>) and a bottom wall (<NUM>) connected to each of the plurality of side walls (<NUM>), wherein the bottom wall (<NUM>) and the plurality of side walls (<NUM>) together define a receiving space (<NUM>) to receive at least a portion (<NUM>) of the blade (<NUM>) and the at least one component (<NUM>, <NUM>) therein;
an intensifier tool (<NUM>) disposed on the at least one component (<NUM>, <NUM>), wherein the intensifier tool (<NUM>) includes a heating device (<NUM>) configured to heat the at least one component (<NUM>, <NUM>);
an adhesive layer (<NUM>) disposed between the at least one component (<NUM>, <NUM>) and the blade (<NUM>); and
a pressure applicator (<NUM>),
wherein the adhesive layer (<NUM>) has a uniform bond thickness (T1) along a length (L1) of the at least one component (<NUM>, <NUM>) due to the pressure applied by the pressure applicator (<NUM>), and wherein, upon being heated by the heating device (<NUM>), the adhesive layer (<NUM>) is cured, thereby coupling the at least one component (<NUM>, <NUM>) to the blade (<NUM>);
the system (<NUM>) being characterised in that:
the intensifier tool (<NUM>) includes a plate (<NUM>) that is configured to contact the at least one component (<NUM>, <NUM>), the heating device (<NUM>) being coupled to the plate (<NUM>);
a pressure strip (<NUM>) is coupled to the plate (<NUM>) of the intensifier tool (<NUM>) and the blade (<NUM>), the pressure strip (<NUM>) fully enclosing the plate (<NUM>); and
the pressure applicator (<NUM>) is coupled to the pressure strip (<NUM>) and is configured to apply a pressure on the plate (<NUM>).