Coupling part structure for vane and jet engine including the same

A coupling support member including a pair of divided pieces is placed in a coupling part between a vane proximal end portion of a guide vane and an attachment flange, and the pair of divided pieces are joined to the vane proximal end portion from both the sides in the vane thickness direction. A groove is formed in one end portion joint surface of the coupling support member, a linear protrusion is formed on the other end portion joint surface, the vane proximal end portion is formed into a concavo-convex shape, a linear protrusion that is engaged with the groove which is formed in the end portion joint surface is formed on a joint surface to the one end portion joint surface, a groove that is engaged with the linear protrusion formed on the end portion joint surface is formed in the joint surface to the other end portion joint surface. The vane proximal end portion is held between the pair of divided pieces of the coupling support member, by the fastening force that is applied to the coupling support member from both the sides in the vane thickness direction. It is possible to obtain a high structural strength while contributing to a reduction in weight of a jet engine.

TECHNICAL FIELD

The present invention relates to, for example, a coupling part structure for a vane used for a coupling part to an engine main body, of guide vanes that are vanes constituting an aircraft jet engine, and a jet engine including the coupling part structure for the vane.

BACKGROUND ART

Such a jet engine as described above is normally provided with: rotor blades for introducing air into an engine main body; and guide vanes that are stator vanes for controlling a flow of the air introduced by the rotor blades.

The guide vanes may be required to have only the flow controlling function, and may be required to also have a structural function of coupling a fan frame and a fan case constituting the engine main body, in addition to the flow controlling function.

In the former case where the guide vanes are required to have only the flow controlling function, a metal material such as an aluminum alloy or a composite material of thermosetting resin such as epoxy resin and reinforcement fiber such as carbon fiber is normally adopted as the constituent material of each guide vane, and a strut that is placed downstream of the guide vanes and is made of a metal material such as an aluminum alloy as its constituent material is provided with the structural function. Meanwhile, in the case where the guide vanes are required to also have the structural function in addition to the flow controlling function, a metal material such as an aluminum alloy is adopted as the constituent material of each guide vane.

Such guide vanes as described above and a jet engine including the guide vanes are described in, for example, Patent Documents 1 to 3.

PRIOR ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

Here, in response to a demand of recent years for a higher bypass ratio for the purpose of enhancing the fuel efficiency of an aircraft jet engine, the engine diameter tends to be made larger. Along with this, the weight of the aircraft jet engine needs to be urgently reduced.

For example, in the case where the guide vanes are provided with only the flow controlling function, the weight of each guide vane itself can be reduced by an amount corresponding to using the composite material as its constituent material, whereas the reduction in weight of the aircraft jet engine is prevented by an amount corresponding to assigning the structural function to the strut that is made of the metal material such as the aluminum alloy as its constituent material.

On the other hand, in the case where the guide vanes are provided with the structural function in addition to the flow controlling function, the metal material such as the aluminum alloy is used as the constituent material of each guide vane, and hence the reduction in weight of the aircraft jet engine is prevented, which is the same problem as that in the case of using the strut. This is a conventional problem to be solved.

The present invention, which has been made in view of the above-mentioned conventional problem, has an object to provide a coupling part structure for a vane capable of obtaining a high structural strength while contributing to a reduction in weight of a jet engine, and a jet engine including the coupling part structure for the vane.

Means for Solving the Problems

In order to achieve the above described object, the present invention provides a coupling part structure for a vane that constitutes a jet engine and is made of a composite material of thermosetting resin or thermoplastic resin and reinforcement fiber, the coupling part structure comprising a vane coupling part, wherein the vane coupling part includes a coupling support member placed therein, the coupling support member being made of metal and including a pair of divided pieces separated from each other, the pair of divided pieces being joined to an end portion of the vane from both sides in a vane thickness direction, on an either one of respective end joint surfaces of the pair of divided pieces of the coupling support member, a linear protrusion is formed in an axis direction of the jet engine, and in the other end joint surface, a groove is formed in the axis direction of the jet engine to face the linear protrusion, the end portion of the vane is formed into a concavo-convex shape in a state with a constant vane thickness in a radial direction of the jet engine, the end portion of the vane has a groove that is engaged with the linear protrusion which is formed on the one end joint surface of either one of the pair of divided pieces, in either one joint surface of joint surfaces to the pair of divided pieces, and has a linear protrusion that is engaged with the groove which is formed in the end joint surface of the other one of the pair of divided pieces, on the other joint surface and at a back side position of the groove in the either one joint surface, and the end portion of the vane is held between the pair of divided pieces of the coupling support member, by fastening force that is applied to the pair of divided pieces of the coupling support member from both the sides in the vane thickness direction.

Preferably, an adhesive is interposed between the pair of divided pieces of the coupling support member and the end portion of the vane held between the pair of divided pieces.

The vane is preferably a stator vane of the jet engine.

The present invention further provides a jet engine including the above-mentioned coupling part structure for the vane as a coupling part structure for a vane constituting the jet engine.

Here, the coupling part structure for the vane according to the present invention can be applied to: a coupling part between a vane distal end portion of a guide vane that is a stator vane of a jet engine and an engine main body; and a coupling part between a vane proximal end portion of, similarly, the guide vane and the engine main body, and can also be applied to: a coupling part between a tip (distal end portion) of a rotor blade of the jet engine and a tip shroud; and a coupling part between a hub (proximal end portion) of, similarly, the rotor blade and a shaft. Note that the tip shroud is provided to the tip of the rotor blade for the purpose of vibration prevention and aerodynamic performance improvement, and rotates together with the rotor blade.

In the coupling part structure for the vane according to the present invention, the linear protrusions or grooves formed on the end joint surface(s) of the coupling support member (the grooves or linear protrusions formed on the joint surface(s) of the end portion of the vane to the coupling support member) can be trapezoidal, semicircular, triangular, and rectangular in cross-section, but are not limited to these shapes.

Further, in the coupling part structure for the vane according to the present invention, examples of the thermosetting resin usable to form the vane include epoxy resin, phenolic resin, and polyimide resin, and examples of the thermoplastic resin usable to form, similarly, the vane include polyetherimide, polyether ether ketone, and polyphenylene sulfide. Then, examples of the reinforcement fiber usable to form the vane include carbon fiber, aramid fiber, and glass fiber. The vane is formed by, for example, laminating the composite material of these substances in the vane thickness direction or three-dimensionally inweaving the composite material thereof. Meanwhile, metal such as an aluminum alloy and a titanium alloy can be used to form the coupling support member.

In the coupling part structure for the vane according to the present invention, first, the end portion of the vane made of the composite material is located between the pair of divided pieces of the coupling support member made of the metal. Further, the groove which is formed in either one joint surface to the coupling support member in the end portion of the vane is engaged with the linear protrusions which is formed on either one end joint surface of the coupling support member, and the linear protrusions which is formed on the other joint surface to the coupling support member in the end portion of the vane is engaged with the groove which is formed in the other end joint surface of the coupling support member. In this state, for example, the fastening force obtained by the bolts and the nuts is applied to the pair of divided pieces of the coupling support member from both the sides in the vane thickness direction, whereby the end portion of the vane is held between the pair of divided pieces of the coupling support member.

Accordingly, the coupling part structure for the vane according to the present invention is capable of obtaining a high structural strength while contributing to a reduction in weight of the jet engine. In addition, because the coupling strength is a mechanical coupling strength, process management for the coupling part is facilitated compared with the coupling strength in the case of using only an adhesive, for example.

Further, because the end portion of the vane is sandwiched between the pair of divided pieces from both the sides in the vane thickness direction, a turn of the end portion of the vane can be avoided compared with, for example, the case where the end portion of the vane is supported by only one of the divided pieces. As a result, a strong coupling state can be maintained.

Moreover, at the time of assembling of the end portion of the vane and the coupling support member, the groove and the linear protrusion in the end portion of the vane is engaged with the linear protrusion and the groove in the coupling support member, whereby the two components are positioned with each other. Accordingly, this assembling work is facilitated.

Furthermore, the end portion of the vane is formed into a concavo-convex shape while the vane thickness is kept constant in the radial direction of the jet engine, that is, the groove and the linear protrusion on the vane end portion side are formed by continuous fiber, and therefore, strength can be kept or improved without increasing the number of process steps.

Still further, in the coupling part structure for the vane according to the present invention, if the adhesive is interposed between the pair of divided pieces of the coupling support member and the end portion of the vane held between the pair of divided pieces, a higher structural strength can be obtained, and if the vane is a stator vane of the jet engine, for example, the guide vane, the flow controlling function as required is exhibited.

Here, in the end portion of the vane, a groove and a linear protrusion can be continuously formed on either one joint surface of the joint surfaces to the pair of divided pieces, and a linear protrusion and a groove can be continuously formed on the other joint surface of the joint surfaces to the pair of divided pieces and at respective back side positions of the groove and the linear protrusion in the either one joint surface.

Furthermore, in the end portion of the vane, two grooves can be formed with a space therebetween, for example, in either one joint surface, while two linear protrusions can be formed on the other joint surface and at respective back side positions of the two grooves in the either one joint surface, and if these configurations are adopted, the structural strength is increased more correspondingly to an amount of increase of an adhesion area.

Meanwhile, the jet engine according to the present invention adopts the coupling part structure for the vane according to the present invention, to thereby achieve both a reduction in weight and an increase in strength.

Advantageous Effects of the Invention

A coupling part structure for a vane according to the present invention produces an excellent effect of obtaining a high structural strength while contributing to a reduction in weight of a jet engine.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention is described with reference to the drawings.

FIG. 1toFIG. 4illustrate one embodiment of a coupling part structure for a vane according to the present invention, and a coupling part of each guide vane as a stator vane constituting a jet engine is described as an example in this embodiment.

As illustrated inFIG. 1, in a jet engine1, an annular core flow passage4is formed on a shaft core side of an engine inner cylinder3of an engine main body2, and a bypass flow passage6is formed between the inner circumferential surface of a fan case5and the outer circumferential surface of the engine inner cylinder3corresponding to an outer portion of the engine main body2.

In a front portion (on the left side ofFIG. 1) of the jet engine1, a fan disc7is rotatably set around the engine shaft core (not illustrated) with the intermediation of a bearing8. The fan disc7is integrally coupled to a turbine rotor of a low-pressure turbine (not illustrated) placed in a back portion (on the right side ofFIG. 1) of the jet engine1.

Further, on the outer circumferential surface of the fan disc7, a plurality of rotor blades10are placed at regular intervals in the circumferential direction with the intermediation of fitting grooves7a, and spacers11,11are respectively placed in a front portion and a back portion between each rotor blade10and each fitting groove7a. Annular retainers12,13that support the rotor blades10are respectively integrally set in the circumferential direction in a front portion and a back portion of the fan disc7. The retainer12in the front portion is integrally coupled to a nose cone14, and the retainer13in the back portion is coaxially and integrally coupled to a rotor16of a low-pressure compressor15that is adjacently placed downstream of the fan disc7.

Note that tip shrouds for vibration prevention and aerodynamic performance improvement are respectively coupled between the tips of the plurality of rotor blades10, and the tip shrouds are not illustrated inFIG. 1.

That is, when the jet engine1is operated, the plurality of rotor blades10are rotated together with the fan disc7, whereby air can be introduced into the core flow passage4and the bypass flow passage6.

The jet engine1includes a plurality of guide vanes (stator vanes)20on the bypass flow passage6. The plurality of guide vanes20are placed at regular intervals around the engine inner cylinder3, and regulate a swirling flow of air flowing in the bypass flow passage6. A composite material of: thermosetting resin (such as epoxy resin, phenolic resin, and polyimide resin) or thermoplastic resin (such as polyetherimide, polyether ether ketone, and polyphenylene sulfide); and reinforcement fiber (such as carbon fiber, aramid fiber, and glass fiber) is used as the constituent material of each guide vane20. The guide vane20is formed by, for example, laminating the constituent material in the vane thickness direction or three-dimensionally in weaving the constituent material.

A vane proximal end portion (vane end portion)21on a shaft core side of each guide vane20is coupled to an attachment flange31fof a fan frame31placed on the engine inner cylinder3, and a vane distal end portion (vane end portion)22on a side farther from the shaft core of the guide vane20is coupled to an attachment flange5fplaced on the fan case5.

In this case, as illustrated inFIG. 2andFIG. 4, a coupling support member33including a pair of divided pieces34,34separated from each other is placed in a coupling part between the vane proximal end portion21of the guide vane20and the attachment flange31f, namely, a vane coupling part, and the pair of divided pieces34,34are joined to the vane proximal end portion21of the guide vane20from both the sides in the vane thickness direction (the left-right direction inFIG. 2). Each of the divided pieces34,34of the coupling support member33is made of metal such as an aluminum alloy and a titanium alloy, and is attached to the attachment flange31fusing a bolt38and a nut39.

Opposed walls35facing each other are respectively formed on the pair of divided pieces34,34of the coupling support member33, and the opposed walls35,35are joined to the vane proximal end portion21of the guide vane20from both the sides in the vane thickness direction.

Here, in a divided piece34at a left side ofFIG. 2of the two divided pieces34,34which configure the coupling support member33, that is, in an end joint surface35aof the opposed wall35in the divided piece34at the left side ofFIG. 2, a groove35bhaving a section forming a trapezoidal shape is formed in an engine axis direction, and in the divided piece34at a right side ofFIG. 2of the two divided pieces34,34, that is, in an end joint surface35aof the opposed wall35in the divided piece34at the right side ofFIG. 2, a linear protrusion35chaving a section forming a trapezoidal shape is formed to face the groove35b.

Meanwhile, as is also shown inFIG. 3, the vane proximal end portion21of the guide vane20is formed into a concavo-convex shape in a state with a constant vane thickness in a radial direction of the engine, and on a joint surface21aat the left side ofFIG. 2of the joint surfaces21a,21ain the vane proximal end portion21of the guide vane20, a linear protrusion21bthat mutually engages with the groove35bwhich is formed in the end joint surface35ain the divided piece34at the left side ofFIG. 2is formed, and a groove21cthat mutually engages with the linear protrusion35cwhich is formed on the end joint surface35ain the divided piece34at the right side ofFIG. 2is formed on the joint surface21aat the right side ofFIG. 2of the joint surfaces21a,21aand at a back side position of the linear protrusion21bin the joint surface21aat the left side ofFIG. 2.

Then, in this embodiment, the vane proximal end portion21of the guide vane20is held between the respective opposed walls35,35of the pair of divided pieces34,34by the fastening force that is applied by a bolt36and a nut37to the pair of divided pieces34,34of the coupling support member33from both the sides in the vane thickness direction.

Further, in this embodiment, an adhesive is interposed between the respective opposed walls35,35of the pair of divided pieces34,34of the coupling support member33and the vane proximal end portion21of the guide vane20held between the opposed walls35,35.

Meanwhile, a coupling support member53including a pair of divided pieces54,54separated from each other is placed also in a coupling part between the vane distal end portion22of the guide vane20and the attachment flange5f, namely, a vane coupling part, and the pair of divided pieces54,54are joined to the vane distal end portion22of the guide vane20from both the sides in the vane thickness direction (the left-right direction inFIG. 2). Each of the divided pieces54,54of the coupling support member53is made of metal such as an aluminum alloy and a titanium alloy, and is attached to the attachment flange5fusing the bolt38and the nut39.

Opposed walls55,55facing each other are respectively formed also on the pair of divided pieces54,54of the coupling support member53, and the opposed walls55,55are joined to the vane distal end portion22of the guide vane20from both the sides in the vane thickness direction.

Also in this vane coupling part, in a divided piece54at a left side ofFIG. 2of the two divided pieces54,54which configure the coupling support member53, that is, in an end joint surface55aof the opposed wall55in the divided piece54at the left side ofFIG. 2, a groove55bhaving a section forming a trapezoidal shape is formed in an engine axis direction, and in the divided piece54at a right side ofFIG. 2of the two divided pieces54,54, that is, in an end joint surface55aof the opposed wall55in the divided piece54at the right side ofFIG. 2, a linear protrusion55chaving a section forming a trapezoidal shape is formed to face the groove55b.

Meanwhile, the vane distal end portion22of the guide vane20is formed into a concavo-convex shape in a state with a constant vane thickness in the radial direction of the engine, and on a joint surface22aat the left side ofFIG. 2of the joint surfaces22aand22ain the vane distal end portion22of the guide vane20, a linear protrusion22bthat mutually engages with the groove55bwhich is formed in the end portion joint surface55ain the divided piece54at the left side ofFIG. 2is formed, and a groove22cthat mutually engages with the linear protrusion55cwhich is formed on the end portion joint surface55ain the divided piece54at the right side ofFIG. 2is formed on the joint surface22aat the right side ofFIG. 2of the joint surfaces22a,22a, and at a back side position of the linear protrusion22bin the joint surface22aat the left side ofFIG. 2.

Then, the vane distal end portion22of the guide vane20is held between the respective opposed walls55,55of the pair of divided pieces54,54by the fastening force that is applied by a bolt56and a nut57to the pair of divided pieces54,54of the coupling support member53from both the sides in the vane thickness direction.

Further, also in this vane coupling part, an adhesive is interposed between the respective opposed walls55,55of the pair of divided pieces54,54of the coupling support member53and the vane distal end portion22of the guide vane20held between the opposed walls55,55.

As described above, in the coupling part structure for the vane according to this embodiment, first, the vane proximal end portion21of each guide vane20made of the composite material is located between the respective opposed walls35,35of the pair of divided pieces34,34of the coupling support member33made of the metal.

Further, the linear protrusion21bformed on the joint surface21aon the left side ofFIG. 2of the vane proximal end portion21is engaged with the groove35bformed on the joint surface35aon the left side ofFIG. 2of the coupling support member33, and the groove21cformed on the joint surface21aon the right side ofFIG. 2of the vane proximal end portion21is engaged with the linear protrusion35cformed on the joint surface35aon the right side ofFIG. 2of the coupling support member33.

In this state, the fastening force obtained by the bolts36and the nuts37is applied to the pair of divided pieces34,34of the coupling support member33from both the sides in the vane thickness direction, whereby the vane proximal end portion21is held between the respective opposed walls35,35of the pair of divided pieces34,34.

Similarly, the vane distal end portion22of each guide vane20is located between the respective opposed walls55,55of the pair of divided pieces54,54of the coupling support member53made of the metal. Further, the linear protrusion22bformed on the joint surface22aon the left side ofFIG. 2of the vane distal end portion22is engaged with the groove55bformed on the joint surface55aon the left side ofFIG. 2of the coupling support member53, and the groove22cformed on the joint surface22aon the right side ofFIG. 2of the vane distal end portion22is engaged with the linear protrusion55cformed on the joint surface55aon the right side ofFIG. 2of the coupling support member53. In this state, the fastening force obtained by the bolts56and the nuts57is applied to the pair of divided pieces54,54of the coupling support member53from both the sides in the vane thickness direction, whereby the vane distal end portion22is held between the respective opposed walls55,55of the pair of divided pieces54,54.

Accordingly, the coupling part structure for the vane according to this embodiment is capable of obtaining a high structural strength while contributing to a reduction in weight of the jet engine1. In addition, because the coupling strength is a mechanical coupling strength, process management for the coupling part is facilitated compared with the coupling strength in the case of using only an adhesive, for example.

Further, because the vane proximal end portion21(vane distal end portion22) is sandwiched between the respective opposed walls35,35(55,55) of the pair of divided pieces34,34(54,54) from both the sides in the vane thickness direction, a turn of the vane proximal end portion21(the vane distal end portion22) can be avoided compared with, for example, the case where the vane proximal end portion21(the vane distal end portion22) is supported by a wall on one side. As a result, a strong coupling state can be maintained.

Moreover, at the time of assembling of the vane proximal end portion21(the vane distal end portion22) and the coupling support member33(53), the groove21c(22c) and the linear protrusion21b(22b) of the vane proximal end portion21(the vane distal end portion22) are respectively engaged with the linear protrusion35c(55c) and the groove35b(55b) of the coupling support member33(53), whereby the two components are positioned with each other. Accordingly, this assembling work is facilitated.

Furthermore, the vane proximal end portion21(the vane distal end portion22) is formed into a concavo-convex shape while keeping the vane thickness constant in the radial direction of the engine, that is, the groove21c(22c) and the linear protrusion21b(22b) on the vane proximal end portion21(the vane distal end portion22) side are molded by continuous fiber, and therefore, strength can be kept or improved without increasing the number of process steps.

Still further, in the coupling part structure for the vane according to this embodiment, the adhesive is interposed between the respective opposed walls35,35(55,55) of the pair of divided pieces34,34(54,54) of the coupling support member33(53) and the vane proximal end portion21(the vane distal end portion22) of the guide vane20held between the opposed walls35,35(55,55), and hence a higher structural strength can be obtained. In this embodiment, the vane is the guide vane20as a stator vane of the jet engine1, and therefore, the original flow controlling function of the guide vane20is exhibited.

Then, the jet engine according to this embodiment adopts the above-mentioned coupling part structure for the vane, and thus achieves both a reduction in weight and an increase in strength.

In the above-mentioned embodiments, description is given of an example case where the coupling part structure for the vane according to the present invention is applied to the vane coupling part of each guide vane as the stator vane of the jet engine, but the present invention is not limited thereto. For example, as illustrated inFIG. 5, the coupling part structure for the vane according to the present invention can also be applied to a coupling part between: a tip (distal end portion)62of each rotor blade60of the jet engine; and a tip shroud85that is provided to the tip62for the purpose of vibration prevention and aerodynamic performance improvement and rotates together with the rotor blade60.

That is, in this embodiment, in a joint surface75aat the left side ofFIG. 5of respective joint surfaces75a,75ain a pair of divided pieces74,74of a link support body73, a groove75bhaving a section forming a trapezoidal shape is formed, and on a joint surface75aat the right side ofFIG. 5of the respective joint surfaces75a,75a, a linear protrusion75cis formed to face the groove75b.

Meanwhile, the tip62of the rotor blade60is formed into a concavo-convex shape, and on a joint surface62aat the left side ofFIG. 5of the joint surfaces62a,62ain the tip62of the rotor blade60, a linear protrusion62bthat engages with the groove75bwhich is formed in the joint surface75ain the divided piece74at the left side ofFIG. 5is formed, and a groove62cthat mutually engages with the linear protrusion75cwhich is formed on the joint surface75ain the divided piece74at the right side ofFIG. 5is formed, on the joint surface62aat the right side ofFIG. 5of the joint surfaces62a,62a.

In this way, the coupling part structure for the vane according to the above-mentioned embodiment is also capable of obtaining a higher structural strength while contributing to the reduction in weight of the jet engine.

While in the respective embodiments described above, the linear protrusions21b,22b,62band the grooves21c,22c,62con the vane end portion side, and the grooves35b,55b,75band the linear protrusions35c,55c,75con the coupling support member side all form trapezoidal shapes in section, the present invention is not limited thereto, and the linear protrusions and the grooves which have the sections forming semicircular shapes, forming triangular shapes, or forming rectangular shapes can be adopted, as the linear protrusions and the grooves.

Further, while the respective embodiments described above each form the configuration in which one each of the linear protrusions21b,22b,62band the grooves21c,22c,62con the vane end portion side, and the grooves35b,55b,75band the linear protrusions35c,55c,75con the coupling support member side is disposed, the present invention is not limited thereto.

The configurations of the coupling part structure for the vane and the jet engine according to the present invention are not limited to the above-mentioned embodiments.

EXPLANATION OF REFERENCE SIGNS