JP2015206325A - gas turbine engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce bolt fastening for assembly of components constituting a housing and various constituents mounted on the components as much as possible, in a gas turbine engine.SOLUTION: A gas turbine engine has an outline housing portion on a compressor side and a substantially cylindrical outline housing portion on a turbine side. In the gas turbine engine, the end surfaces of the two outline housing portions are fastened by V band coupling and forces in directions of approaching each other are applied, and thereby the inside wall surface of the first outline housing portion and the inside wall surface of the second outline housing portion presses and holds a compressor/diffuser, an inside housing carrying a bearing holding a rotational shaft, and a turbine/nozzle.

Description

  The present invention relates to a gas turbine engine, and more particularly, to a housing structure of a gas turbine engine.

  A gas turbine engine typically includes a compressor and a turbine configured on a rotation axis, and an annular combustor coaxial with the rotation axis. The air sucked by the rotation of the rotating shaft is compressed, the compressed air enters the combustor and burns to become a high temperature gas flow, and the high temperature gas flow rotates the rotating shaft of the turbine connected to or integrated with the rotating shaft of the compressor, The rotational energy is obtained as output, and part of it is spent for compressing the intake air. In the actual configuration of such a gas turbine engine, the rotating shaft is configured to rotate with a rotating shaft such as a compressor impeller and a turbine rotor vane, and the rotating body is surrounded by a bearing so as to surround the rotating body in the rotating direction. In addition, various fixed configurations such as a combustor, a compressor diffuser, a turbine nozzle, and a turbine stator are provided, and these structures are entirely covered by an outer housing.

  In the structure of a gas turbine engine as described above, the outer housing and the inner housing for positioning and fixing the structure such as the bearing, the diffuser of the compressor, and the turbine nozzle are typically at least structurally. It consists of parts divided into 3 to 4 or more points. When the engine assembly is configured, the divided parts are fastened by bolts or the like. For example, Patent Document 1 describes a configuration in which a compressor differential user, a turbine nozzle, and an outer housing are assembled with bolts in a gas turbine.

JP-A-6-330764 Shokai 59-32131

  As described above, a plurality of parts constituting the gas turbine engine housing and various components mounted thereon are generally fastened to each other by bolts. However, fastening with bolts leads to an increase in the number of parts and assembly man-hours (for bolting), which also causes an increase in cost. That is, of course, a large number of bolts are necessary for fastening with bolts, and a process such as formation of a flange surface and screw hole processing for bolt fastening is necessary, which increases man-hours and costs. . In addition, the number of flange surfaces and bolts is increased, and a tool for fastening bolts can be entered, and a space for assembling operation is also required, which causes an increase in the size and weight of the engine. In particular, in the case of a small engine, the ratio of tightening bolts and the number of processing steps (such as bolt holes) in the cost is relatively large, which is inefficient in terms of labor and cost. . Furthermore, in the case of a structure in which the assembly surface such as a flange surface is fastened with bolts, if a gap is generated due to distortion of a part exposed to high temperature / high pressure gas, problems such as leakage of combustion gas and lubricant may occur. Can occur. Accordingly, a structure that can be assembled without using bolt fastening as much as possible has been desired.

  Thus, one object of the present invention is to provide a novel configuration that minimizes bolt fastening in assembling a plurality of components constituting the housing and various components mounted thereon in the gas turbine engine as described above. Is to provide.

  By the way, generally, a technique called “V-band coupling” is known as a technique for connecting two cylindrical members in their axial directions. In the V-band coupling, in short, a flange portion having a thickness gradually decreasing in the radial direction is provided around the end where two cylindrical members are bonded, and the flange portions of the two cylindrical members are connected to each other. A band (V band) having a groove with a substantially V-shaped cross section along the length direction in a state of being bonded together so that the substantially V-shaped groove is fitted on two bonded flange portions. Are wound around the ends of the two cylindrical members. Then, as the tightening of the V band is tightened, the flange portion enters the narrow portion of the substantially V-shaped groove, whereby the two cylindrical members are fastened together. For example, Patent Document 2 discloses a configuration in which a center housing that surrounds a bearing between a compressor and a turbine and a turbine housing are fastened by V-band coupling in a turbocharger. V-band couplings can be advantageously used to connect two cylindrical members without using bolt fastening. Such knowledge is used in the present invention.

  According to the present invention, the above-described problem is a gas turbine engine that surrounds a compressor and a first cylindrical outer housing portion that extends toward the position of the turbine, and a turbine and a combustor. A second outer housing portion having a substantially cylindrical shape extending toward the compressor and having an end surface facing the end surface of the first outer housing portion, and the end surface of the first outer housing portion and the second outer housing portion. The opposing end surfaces of the second outer housing part are fastened by V-band coupling, and a force in a direction close to each other is applied to the two end surfaces, whereby the axis of the rotation axis of the first outer housing part An inner wall surface extending in a direction substantially perpendicular to the direction and an inner wall surface of the second outer housing portion facing the inner wall surface of the first outer housing portion are the first outer housing. The compressor diffuser and the compressor and the turbine, which are arranged in order along the axial direction of the rotating shaft between the two inner wall surfaces in the interior of the casing portion and the second outer housing portion, are common. This is achieved by a gas turbine engine characterized in that an inner housing carrying a bearing for rotatably holding a rotating shaft and a nozzle of a turbine are pressed and held from both sides in the axial direction of the rotating shaft.

  According to the above configuration, to put it briefly, in the substantially cylindrical outer housing, the compressor side portion (first outer housing portion, hereinafter simply referred to as “compressor side portion”) and the turbine. Fastening with the combustor side part (second outer housing part, hereinafter simply referred to as “turbine side part”) is achieved by V-band coupling as already mentioned. And, among the structures fixed inside the outer housing of the gas turbine engine, at least the component on the fixed side, the compressor diffuser, the inner housing carrying the bearing that rotatably holds the rotating shaft, and the turbine The nozzle is disposed between the compressor side portion and the turbine side portion of the outer housing. When the V-band coupling is tightened in this state, the elastic force of both parts of the outer housing is clamped from the inner wall surface of the compressor side portion and the turbine side portion of the outer housing in the axial direction of the rotary shaft. As a result, the components are pressed between the inner wall surfaces of the compressor side portion and the turbine side portion and held in the respective positions. Thus, in addition to the assembly of the outer housing, it is not necessary to fasten the bolts when assembling the compressor diffuser, the inner housing, and the turbine nozzle to the outer housing. As a result, the number of assembling steps such as formation of bolt holes for bolt fastening and bolt fastening is reduced, and it is not necessary to secure a space for bolt fastening, and the gas turbine can be reduced in size and weight. In order to apply an axial holding force to the internal components of the outer housing, the space between the end surface of the compressor side portion and the end surface of the turbine side portion that are bonded together is the same as that before the V-band coupling is fastened. It is preferable that the dimensions are designed so that there is a slight gap in the state. And by closing the gap by tightening the V-band coupling, the compressor / diffuser, the internal housing, and the turbine nozzle are held between the compressor side part and the inner wall surface of the turbine side part. It is possible to apply a significant pressing force.

  Thus, according to the present invention described above, in the gas turbine engine, it is possible to hold the assembly of the components inside the outer housing by using the tightening by the V-band coupling and the elastic force of the outer housing. Therefore, the number of parts where bolt fastening is used can be greatly reduced, and the number of parts and assembly man-hours can be reduced. In addition, when the number of bolt fastening points is reduced, a bolt fastening structure such as a bolt hole is not required, so the engine structure is greatly simplified, and for example, the influence of distortion of each part due to heat is expected to be reduced. It is also expected to reduce the size and weight of the engine and improve reliability.

  Other objects and advantages of the present invention will become apparent from the following description of preferred embodiments of the present invention.

FIG. 1A is a schematic cross-sectional view of a gas turbine according to an embodiment of the present invention as viewed from a direction perpendicular to the rotation axis. FIG. 1 (B) is a diagram schematically showing the manner of fastening the outer housing by V-band coupling. FIG. 1C is a schematic diagram for explaining a method of fixing a compressor / diffuser stationary blade, an inner housing, and a turbine nozzle according to the present invention. FIG. 2 is a schematic cross-sectional view of another embodiment of the gas turbine according to the present invention as viewed from the direction perpendicular to the rotation axis.

DESCRIPTION OF SYMBOLS 1 ... Gas turbine engine 2 ... Generator 3 ... Compressor 3a ... Compressor impeller 4 ... Combustor 5 ... Turbine 5a ... Turbine vane 6 ... Exhaust port 7 ... Outer housing housing / compressor side portion 8 ... Outer housing housing / turbine side portion 7a, 8a ... Flange 9 ... Internal housing 10 ... Rotating shaft 11 ... Bearing 13 ... Compressor / diffuser stationary blade 15 ... Turbine / nozzle 20 ... V-band 20a ... V-band coupler

  The present invention will now be described in detail with reference to a few preferred embodiments with reference to the accompanying drawings. In the figure, the same reference numerals indicate the same parts.

  As schematically illustrated in FIG. 1A, the basic configuration of a gas turbine engine 1 according to one embodiment of the present invention may be the same as a typical gas turbine engine, and the rotation axis S A compressor 3 and a turbine 5 are formed on a rotating shaft 10 that rotates around. After the air sucked at the intake port of the compressor 3 is once accelerated by the rotation of the compressor / impeller 3b, the compressor -It passes through the diffuser 13 and is decelerated and compressed. The compressed air is sent to the combustor 4, where it is mixed with the fuel injected from the fuel nozzle 4 a and burned, and the combustion gas passes through the turbine nozzle 15 to the turbine 5. When flowing in and passing through the turbine vane 5 a, the rotating shaft 10 is rotated and the exhaust gas is discharged from the exhaust port 6. A part of the rotational energy generated by the turbine of the rotating shaft 10 is used for rotational driving of the compressor / impeller 3b, and the rest is converted into electric energy by the rotation of the rotor portion of the generator 2 and extracted outside. It becomes. In the illustrated example, the rotary shaft 10 includes a bearing 11 carried on a cylindrical inner housing 9 between the compressor 3 and the turbine 5 and disposed substantially coaxially with the rotary shaft 10, and the compressor 3 and the power generator. It is supported by the bearing 2a provided in the stator part of the generator 2 between the generators 2. The bearing 2a and the bearing 11 may be air bearings, for example.

  Further, in the above configuration, the compressor 3, the combustor 4, and the turbine 5 are surrounded by a substantially cylindrical outer shell housing disposed substantially coaxially with the rotary shaft 10 on the outer periphery thereof. The outer shell housing surrounds the impeller 3 b and the diffuser 13 of the compressor 3 from the intake port of the compressor 3 and extends in the direction of the turbine 5, and surrounds the combustor 4 and the turbine 5 from the exhaust port 6. A turbine-side portion 8 extending in the direction of the compressor 3, and a substantially annular end 7 a of the compressor-side portion 7 and a substantially annular end 8 a of the turbine-side portion 8, as shown in the figure, Opposed to each other. Further, between the wall surface 7b extending in a plane substantially perpendicular to the rotation axis S of the compressor side portion 7 and the wall surface on the compressor 3 side extending in a plane substantially perpendicular to the rotation axis S of the internal housing 9, The compressor / diffuser 13 is assembled, and a wall surface 8b extending in a plane substantially perpendicular to the rotation axis S of the turbine side portion 8 and a turbine 5 extending in a plane substantially perpendicular to the rotation axis S of the internal housing 9 are provided. The turbine nozzle 15 is assembled between the side wall surfaces.

  In the gas turbine configuration as described above, conventionally, for example, the end portion 7a of the compressor side portion 7 and the end portion 8a of the turbine side portion 8 are fastened, the compressor / diffuser 13, the internal housing 9 and the turbine nozzle 15 are used. The assembly of was usually done using bolts (bolt fastening). However, bolt fastening requires a lot of man-hours such as forming a flange, drilling a bolt hole, and screwing a bolt. In addition, providing a flange portion, securing a space for enabling the screw screwing operation, The mounting of the nuts causes an increase in the size and weight of each part. Therefore, in the present invention, in the above configuration, first, the end portion 7a of the compressor side portion 7 of the outer housing and the end portion 8a of the turbine side portion 8 are fastened by V-band coupling. Then, when the compressor side portion 7 and the turbine side portion 8 are tightened by the V-band coupling, the compressor diffuser 13, the internal housing 11 and the turbine nozzle 15 sandwiched between these wall surfaces Since the pressing force acts in the direction, the components are held by the pressing force.

  Specifically, first, as schematically illustrated in FIG. 1B, the cylinders at the end portion 7a of the compressor side portion 7 and the end portion 8a of the turbine side portion 8 of the outer housing are cylindrical. A flange portion whose width gradually decreases in the radial direction is formed along the circumferential direction of the shape. As shown in the drawing, the V band 20 having the substantially V-shaped groove 20a in the cross section in the state where the flanges of the end portion 7a and the end portion 8a face each other is formed into a substantially V-shaped groove. Winding is performed along the circumferential direction of the cylindrical shape of the end portion 7a and the end portion 8a so that the flanges of the end portion 7a and the end portion 8a are fitted inside 20a. Then, as the circumferential length of the V-band 20 becomes shorter, the V-band 20 is biased inward in the cylindrical radial direction of the end 7a and the end 8a (in the direction of the downward arrow in the figure). At the same time, the flanges of the end portion 7a and the end portion 8a are inserted deeply into the substantially V-shaped groove 20a, so that the flanges of the end portion 7a and the end portion 8a are close to each other (see FIG. A force acts in the middle and the direction of the horizontal arrow), whereby the flanges of the end 7a and the end 8a are fastened to each other as shown in FIG. 1B. When the V band 20 is fastened, the end 7a and the end 8a are brought close to each other by tightening the V band 20, and a wall surface 7b extending on a surface substantially perpendicular to the rotation axis S of the compressor side portion 7 of the outer housing; Since the wall surface 8b extending on the surface substantially perpendicular to the rotation axis S of the turbine side portion 8 is also biased in the approaching direction, as schematically illustrated in FIGS. 1 (A) and 1 (C), The compressor / diffuser 13, the internal housing 11 and the turbine nozzle 15 sandwiched between the wall surface 7 b and the wall surface 8 b are subjected to elastic pressing force from both sides of the wall surface 7 b and the wall surface 8 b in the axial direction of the rotating shaft. Thus, the compressor / diffuser 13, the inner housing 11, and the turbine nozzle 15 are each held at that portion. That is, in the configuration of the present invention, the end portion 7a of the compressor side portion 7 and the end portion 8a of the turbine side portion 8 are fastened by V-band coupling. 11 and the turbine nozzle 15 can also be achieved by the pressing force applied from the wall surface 7b and the wall surface 8b without using bolt fastening.

  Note that the compressor 7, the diffuser 13, the internal housing 11, and the turbine nozzle 15 are retained by the fastening of the end portion 7 a and the end portion 8 a by the fastening of the V band 20 and the pressing force between the wall surface 7 b and the wall surface 8 b. Therefore, preferably, before the V-band 20 is tightened, the compressor side portion 7 and the turbine in the direction of the rotation axis S are arranged so that a significant gap is formed between the end portion 7a and the end portion 8a. The dimension of the side part 8 is set. It should be understood that the width of the gap can be appropriately selected by those skilled in the art based on the overall dimensions and materials of the compressor side portion 7 and the turbine side portion 8. In the case of a typical small gas turbine engine, the width of the gap between the end 7a and the end 8a before tightening the V-band 20 is, for example, about 0.3 to 0.5 mm. It is not limited to this.

  Further, in the above configuration, a heat insulating layer (not shown) is provided inside the exhaust port 6 in order to suppress the influence of the thermal distortion of the turbine side portion 8 of the outer housing due to the heat from the exhaust port 6. Alternatively, an arbitrary cooling mechanism (such as circulating cooling air) may be provided. Further, as schematically illustrated in FIG. 2, a bellows structure 22 may be formed on a part of the turbine side portion 8 so as to absorb thermal distortion of the turbine side portion 8 of the outer housing. The structure for absorbing distortion such as the bellows structure 22 may be provided in other parts of the housing.

  Thus, according to the configuration of the present invention described above, the compressor side portion 7 and the turbine side portion 8 are adopted by adopting the V-band coupling in the fastening of the compressor side portion 7 and the turbine side portion 8 of the outer housing. Fastening by bonding and assembly of other parts are achieved only by fastening the V-band, and this makes it possible to reduce the number of bolt fastening parts.

  Although the above description has been made in relation to the embodiment of the present invention, many modifications and changes can be easily made by those skilled in the art, and the present invention is limited to the embodiment exemplified above. It will be apparent that the invention is not limited and applies to various devices without departing from the inventive concept. For example, the present invention can be applied not only to a simple cycle gas turbine engine as shown, but also to a regenerative cycle gas turbine engine.

Claims (1)

  A gas turbine engine having a generally cylindrical first outer housing portion surrounding the compressor and extending toward the turbine, and surrounding the turbine and combustor and extending toward the compressor. A second outer housing portion having a substantially cylindrical shape and having an end surface facing the end surface of the first outer housing, and the second outer housing facing the end surface of the first outer housing portion and the second outer housing portion. A direction substantially perpendicular to the axial direction of the rotation axis of the first outer housing portion is obtained by applying a force in a direction close to each other to the two end surfaces by fastening with an end surface of the portion by a V-band coupling. An inner wall surface extending to the inner wall surface of the second outer housing portion facing the inner wall surface of the first outer housing portion. A diffuser of the compressor disposed in order along the axial direction of the rotating shaft between the two inner wall surfaces in the inside of the hooding portion and the second outer housing portion; and the compressor and the turbine A gas turbine engine characterized in that an internal housing carrying a bearing for rotatably holding a common rotating shaft therebetween and a nozzle of the turbine are pressed and sandwiched from both axial sides of the rotating shaft. .

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