KR102157899B1 - Bucket fixing apparatus for turbine and bucket assembling method using the same - Google Patents

Abstract

The present invention relates to a bucket fixing device for a turbine and a bucket assembly method using the same. The bucket fixing device for a turbine of the present invention includes: a locking key that is positioned on a lower surface of a bucket to fix a final bucket among buckets assembled on a rotor disk and is inserted into an insertion space formed by a first insertion groove and a second insertion groove; and a fixing seat that is inserted between the first bucket and the final bucket to fix the locking key. According to the present invention, it is possible to quickly and smoothly assemble or disassemble the bucket to or from the rotor disk, and it is not necessary to form a through hole in a bucket platform unit.

Description

Bucket fixing apparatus for turbine and bucket assembling method using the same}

The present invention relates to a bucket fixing device for a turbine and a bucket assembly method using the same.

A turbine is a mechanical device that obtains rotational force by impulsive or reaction force by using a flow of a compressible fluid such as steam or gas, and includes a steam turbine using steam and a gas turbine using high temperature combustion gas.

Among these, the gas turbine is largely composed of a compressor, a combustor and a turbine. The compressor is provided with an air inlet for introducing air, and a plurality of compressor vanes and compressor blades are alternately arranged in the compressor housing.

The combustor supplies fuel to the compressed air compressed by the compressor and ignites it with a burner, thereby generating high-temperature and high-pressure combustion gas.

In the turbine, a plurality of turbine vanes and turbine blades are alternately arranged in a turbine housing. In addition, a rotor is disposed so as to pass through the center of the compressor, combustor, turbine and exhaust chamber.

Both ends of the rotor are rotatably supported by bearings. Further, a plurality of disks are fixed to the rotor so that each blade is connected, and a drive shaft such as a generator is connected to an end of the exhaust chamber side.

Since these gas turbines do not have a reciprocating mechanism such as a piston of a four-stroke engine, there is no mutual friction part such as a piston-cylinder, so the consumption of lubricating oil is extremely low. There is an advantage.

Briefly describing the operation of the gas turbine, the compressed air in the compressor is mixed with fuel and combusted to produce a high-temperature combustion gas, and the thus produced combustion gas is injected to the turbine side. The injected combustion gas passes through the turbine vane and the turbine blade to generate a rotational force, thereby rotating the rotor.

US patent publication US6416286

An object of the present invention is to provide a bucket fixing device for a turbine that can quickly and smoothly assemble or disassemble a bucket on a rotor disk and does not have to form a through hole in the bucket platform, and a bucket assembly method using the same.

A bucket fixing device for a turbine according to an embodiment of the present invention for achieving the above object includes a rotor disk, a plurality of buckets, a locking key, and a fixing sheet. The rotor disk has a plurality of dovetail grooves disposed to be spaced apart from each other along the circumferential direction, and a platform seating portion formed between the dovetail grooves and having a first insertion groove. The plurality of buckets have a root portion respectively inserted into the dovetail groove, and a platform portion formed on an upper surface of the root portion and having a second insertion groove formed at a position facing the first insertion groove. The locking key is positioned on the lower surface of the bucket to fix the final bucket among the buckets assembled on the rotor disk, and is inserted into the insertion space formed by the first insertion groove and the second insertion groove. The fixing sheet includes a fixing sheet that is inserted between the first bucket and the final bucket next to the final bucket to fix the locking key.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the locking key is inserted into the insertion space between the first bucket and the rotor disk, and after inserting the root of the final bucket into the dovetail groove of the rotor disk, the locking key is finally It can be moved to the insertion space between the bucket and the rotor disk and fixed by the fixing sheet.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the locking key is formed in a rectangular parallelepiped shape elongated in the circumferential direction, and may be inserted in the circumferential direction in the insertion space.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the fixing sheet may be made of a rectangular metal plate.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the fixing sheet may be vertically inserted into a first recess formed in a first bucket next to the final bucket in a radial direction.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the fixing sheet is inserted into the first concave portion and then the portion protruding outward is bent to be inserted into the second concave portion formed on one side of the axial direction of the first bucket. I can.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, a first bucket is inserted into one of n dovetail grooves provided in a circumferential direction of a rotor disk, and formed between one side of the first bucket and one side of the rotor disk. The step of fixing the first bucket by inserting the locking key into the insertion groove, inserting the second to n-1th buckets into the dovetail grooves disposed adjacent to the first bucket, respectively, and inserting the locking key into the insertion groove for a second To fixing the n-1th bucket, inserting the locking key into the insertion groove formed between the other side of the first bucket and the other side of the rotor disk, inserting the nth bucket into the dovetail groove, the n-th locking key And moving the bucket and the rotor disk toward the insertion groove, and fixing the locking key by inserting the fixing sheet into the gap between the first bucket and the n-th bucket.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, in the step of inserting the locking key, the locking key faces the first insertion groove formed between the dovetail groove of the rotor disk and the first insertion groove on the upper surface of the root portion of the bucket. It can be inserted into the second insertion groove formed in the viewing position.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, in the step of inserting the fixing sheet, the fixing sheet may be vertically inserted into the first recess formed on the side of the platform part of the first bucket.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, after the step of fixing the locking key by inserting the fixing sheet, the part protruding to the outside of the inserted fixing sheet is bent, and one side in the axial direction of the first bucket It may further include the step of inserting the second recess formed in the.

A bucket fixing device for a turbine according to an embodiment of the present invention includes a rotor disk, a plurality of buckets, a locking key, and a fixing sheet. The rotor disk has a plurality of dovetail grooves disposed to be spaced apart from each other in a circumferential direction, and a platform seating portion formed between the dovetail grooves and having a first insertion groove. The plurality of buckets have a root portion respectively inserted into the dovetail groove, and a platform portion formed on an upper surface of the root portion and having a second insertion groove formed at a position facing the first insertion groove. The locking key is positioned on the lower surface of the final bucket to fix the final bucket among the buckets assembled on the rotor disk, and is inserted into the insertion space formed by the first insertion groove and the second insertion groove. The fixing sheet is inserted between the first bucket next to the final bucket and between the final bucket and the rotor disk to fix the locking key.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the locking key is inserted into the insertion space between the first bucket and the rotor disk, and after inserting the root of the final bucket into the dovetail groove of the rotor disk, the locking key is first It can be rotated to span the bucket and the insertion space between the final bucket and the rotor disk and fixed by the fixing sheet.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the locking key is formed in a rectangular parallelepiped shape elongated in the radial direction, and can be inserted in the circumferential direction so that the longitudinal direction of the locking key faces the radial direction in the insertion space. .

In the bucket fixing device for a turbine according to an embodiment of the present invention, the fixing sheet may be made of a rectangular metal plate.

In the bucket fixing device for a turbine according to an embodiment of the present invention, the fixing sheet may be inserted circumferentially in a gap between the platform portion of the first bucket and the final bucket and the radial end of the rotor disk.

In the bucket fixing device for a turbine according to an embodiment of the present invention, after the fixing sheet is inserted into the gap, the portion protruding to the outside is bent radially outward to the step portion formed on one side of the axial direction of the first bucket and the final bucket. Can be inserted.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, a first bucket is inserted into one of n dovetail grooves provided in a circumferential direction of a rotor disk, and formed between one side of the first bucket and one side of the rotor disk. The step of fixing the first bucket by inserting the locking key into the insertion groove, inserting the second to n-1th buckets into the dovetail grooves disposed adjacent to the first bucket, respectively, and inserting the locking key into the insertion groove for a second To fixing the n-1th bucket, inserting the locking key into the insertion groove formed between the other side of the first bucket and the other side of the rotor disk, inserting the nth bucket into the dovetail groove, inserting the locking key into the first Rotating the bucket and the insertion groove between the n-th bucket and the rotor disk, and fixing the locking key by inserting a fixing sheet into the gap between the first bucket and the n-th bucket and the rotor disk.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, in the step of inserting the locking key, the locking key faces the first insertion groove formed between the dovetail groove of the rotor disk and the first insertion groove on the upper surface of the root portion of the bucket. It can be inserted in the circumferential direction into the second insertion groove formed at the viewing position.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, in the step of inserting the fixing sheet, the first bucket and the n-th bucket are laid in a circumferential direction and inserted into the gap between the platform portion of the first bucket and the n-th bucket and the radial end of the rotor disk. I can.

In the method of assembling a bucket for a turbine according to an embodiment of the present invention, after the step of fixing the locking key by inserting the fixing sheet, the part protruding to the outside of the inserted fixing sheet is bent radially outward, and the first bucket and It may further include the step of inserting the step portion formed on one side of the axial direction of the n-th bucket.

According to the bucket fixing device for a turbine of the present invention and a bucket assembly method using the same, it is possible to quickly and smoothly assemble or disassemble the bucket in the rotor disk, and it is not necessary to form a through hole in the bucket platform.

1 is a partially cut-away perspective view of a gas turbine according to an embodiment of the present invention.
2 is a cross-sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention.
3 is an exploded perspective view showing the turbine rotor disk of FIG. 2.
4 to 8 are partial perspective views illustrating a process of assembling a bucket to a turbine disk using a bucket fixing device for a turbine according to a first embodiment of the present invention.
9 to 12 are partial perspective views illustrating a process of assembling a bucket to a turbine disk by using the bucket fixing device for a turbine according to a second embodiment of the present invention.

The present invention is intended to illustrate specific embodiments and to be described in detail in the detailed description, since various transformations can be applied and various embodiments can be provided. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood to include all conversions, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present invention, terms such as'comprise' or'have' are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, it should be noted that the same components in the accompanying drawings are indicated by the same reference numerals as possible. In addition, detailed descriptions of known functions and configurations that may obscure the subject matter of the present invention will be omitted. For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated.

1 is a partially cut-away perspective view of a gas turbine according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing a schematic structure of a gas turbine according to an embodiment of the present invention, and FIG. 3 is a turbine rotor disk of FIG. It is an exploded perspective view showing.

As shown in FIG. 1, a gas turbine 1000 according to an embodiment of the present invention includes a compressor 1100, a combustor 1200, and a turbine 1300. The compressor 1100 has a plurality of blades 1110 radially installed. The compressor 1100 rotates the blade 1110 and moves while the air is compressed by the rotation of the blade 1110. The size and installation angle of the blade 1110 may vary depending on the installation location. In one embodiment, the compressor 1100 is directly or indirectly connected to the turbine 1300, and receives a part of the power generated from the turbine 1300 and may be used to rotate the blade 1110.

Air compressed by the compressor 1100 moves to the combustor 1200. The combustor 1200 includes a plurality of combustion chambers 1210 and a fuel nozzle module 1220 arranged in an annular shape.

As shown in FIG. 2, the gas turbine 1000 according to an embodiment of the present invention includes a housing 1010, and a diffuser 1400 through which combustion gas passing through the turbine is discharged at a rear side of the housing 1010. ) Is provided. Further, a combustor 1200 for receiving compressed air and combusting it is disposed in front of the diffuser 1400.

Referring to the air flow direction, the compressor section 1100 is located on the upstream side of the housing 1010 and the turbine section 1300 is located on the downstream side. And, between the compressor section 1100 and the turbine section 1300, a torque tube unit 1500 as a torque transmission member for transmitting the rotational torque generated in the turbine section 1300 to the compressor section 1100 is disposed.

The compressor section 1100 is provided with a plurality of (for example, 14) compressor rotor disks 1120, and each of the compressor rotor disks 1120 is fastened so as not to be spaced apart in the axial direction by a tie rod 1600. Has been.

Specifically, each of the compressor rotor disks 1120 is aligned along an axial direction with a tie rod 1600 constituting a rotating shaft substantially passing through the center. Here, each of the adjacent compressor rotor disks 1120 is disposed so that the opposite surface is pressed by the tie rod 1600 so that relative rotation is impossible.

A plurality of blades 1110 are radially coupled to the outer peripheral surface of the compressor rotor disk 1120. Each blade 1110 has a dovetail portion 1112 and is fastened to the compressor rotor disk 1120.

A vane (not shown) fixed to the housing is positioned between the rotor disks 1120. Unlike the rotor disk, the vanes are fixed so as not to rotate, and serve to guide air to the blades of the rotor disk located downstream by aligning the flow of compressed air that has passed through the blades of the compressor rotor disk.

The dovetail portion 1112 is fastened in a tangential type and an axial type. This may be selected according to the required structure of a commercial gas turbine, and may have a commonly known dovetail or fir-tree. In some cases, the blade may be fastened to the rotor disk by using a fastener other than the above-described form, for example, a key or a fastener such as a bolt.

The tie rod 1600 is disposed to pass through the centers of the plurality of compressor rotor disks 1120 and the turbine rotor disk 1320, and the tie rod 1600 may be composed of one or a plurality of tie rods. . One end of the tie rod 1600 is fastened in the compressor rotor disk located on the uppermost side, and the other end of the tie rod 1600 is fastened by a fixing nut 1450.

The shape of the tie rod 1600 is not necessarily limited to the shape shown in FIG. 2 since it may be formed in various structures depending on the gas turbine. That is, as shown, one tie rod may have a form penetrating the central portion of the rotor disk, a plurality of tie rods may have a form in which a plurality of tie rods are disposed in a circumferential shape, and a mixture of these may be used.

Although not shown, in the compressor of the gas turbine, a vane serving as a guide blade may be installed at the next position of the diffuser in order to adjust the flow angle of the fluid entering the inlet of the combustor to the design flow angle after increasing the pressure of the fluid. And this is called a deswirler.

The combustor 1200 mixes and combusts the introduced compressed air with fuel to produce high-energy high-temperature and high-pressure combustion gas, and increases the temperature of the combustion gas to the heat resistance limit that the combustor and turbine parts can withstand through the isostatic combustion process. do.

A number of combustors constituting the combustion system of a gas turbine can be arranged in a housing formed in a cell shape, a burner including a fuel injection nozzle, etc., a combustor liner forming a combustion chamber, and a combustor. It is configured to include a transition piece (Transition Piece) that becomes the connection part of the turbine and.

Specifically, the liner provides a combustion space in which fuel injected by a fuel nozzle is mixed with compressed air of a compressor and burned. The liner may include a flame barrel providing a combustion space in which fuel mixed with air is combusted, and a flow sleeve surrounding the flame barrel and forming an annular space. In addition, the fuel nozzle is coupled to the front end of the liner, and the spark plug is coupled to the side wall.

On the other hand, at the rear end of the liner, a transition piece is connected to send the combustion gas burned by the spark plug to the turbine side. In such a transition piece, the outer wall portion is cooled by compressed air supplied from a compressor so as to prevent breakage of the combustion gas due to high temperature.

To this end, holes for cooling are provided in the transition piece to inject air into the inside, and compressed air flows toward the liner after cooling the body inside through the holes.

Cooling air cooled by cooling the above-described transition piece flows in the annular space of the liner, and compressed air from the outside of the flow sleeve is provided as cooling air through cooling holes provided in the flow sleeve to collide with the outer wall of the liner.

Meanwhile, the high-temperature, high-pressure combustion gas from the combustor is supplied to the turbine 1300 described above. The supplied high-temperature and high-pressure combustion gas expands and collides with the rotor blades of the turbine, giving reaction force to cause rotational torque, and the resulting rotational torque is transmitted to the compressor through the torque tube described above, and exceeds the power required for driving the compressor. This power is used to drive a generator.

The turbine 1300 is basically similar to the structure of a compressor. That is, the turbine 1300 is also provided with a plurality of turbine rotor disks 1320 similar to the compressor rotor disks of the compressor. Accordingly, the turbine rotor disk 1320 also includes a plurality of turbine blades 1340 disposed radially. The turbine blade 1340 may also be coupled to the turbine rotor disk 1320 in a manner such as a dovetail. In addition, a turbine vane (not shown) fixed to the housing is also provided between the blades 1340 of the turbine rotor disk 1320 to guide the flow direction of the combustion gas passing through the blades.

Referring to FIG. 3, the turbine rotor disk 1320 has a substantially disk shape, and a plurality of coupling slots 1322 is formed at an outer circumference thereof. The coupling slot 1322 is formed to have a curved surface in the form of a fir-tree.

The turbine blade 1340 is fastened to the coupling slot 1322. In FIG. 3, the turbine blade 1340 has a flat plate-shaped platform portion 1341 at an approximately central portion. The platform portion 1341 serves to maintain a gap between the blades by contacting the platform portion 1341 of the adjacent turbine blade and its side surfaces.

A root portion 1342 is formed on the bottom surface of the platform portion 1341. The root portion 1342 has an axial-type shape that is inserted into the coupling slot 1322 of the rotor disk 1320 described above along the axial direction of the rotor disk 1320.

The root portion 1342 has an approximately fir-shaped bent portion, which is formed to correspond to the shape of the bent portion formed in the coupling slot. Here, the coupling structure of the root portion does not necessarily have a fir shape, and may be formed to have a dovetail shape.

A blade portion 1343 is formed on the upper surface of the platform portion 1341. The blade portion 1343 is formed to have an airfoil optimized according to the specifications of the gas turbine, and has a leading edge disposed on the upstream side and a trailing edge disposed on the downstream side based on the flow direction of the combustion gas.

Here, unlike the blades of the compressor, the blades of the turbine are in direct contact with the high temperature and high pressure combustion gas. Since the temperature of the combustion gas is high enough to reach 1700°C, a cooling means is required. To this end, it has a cooling flow path for extracting compressed air from a portion of the compressor and supplying it to the turbine-side blades.

The cooling flow path may extend outside the housing (external flow path) or extend through the inside of the rotor disk (internal flow path), and both external and internal flow paths may be used. In FIG. 3, a plurality of film cooling holes 1344 are formed on the surface of the blade part, and the film cooling holes 1344 communicate with a cooling flow path (not shown) formed inside the blade part 1343 for cooling. It serves to supply air to the surface of the blade portion (1343).

4 to 8 are partial perspective views illustrating a process of assembling a bucket to a turbine disk by using the bucket fixing device for a turbine according to the first embodiment of the present invention.

The turbine rotor disk 1320 and the turbine blade 1340 described above will be described by changing their names and numbers to the rotor disk 100 and the bucket 200, respectively.

The rotor bucket assembly of the turbine according to the first embodiment of the present invention includes a plurality of dovetail grooves 110 disposed to be spaced apart from each other along a circumferential direction, and a platform formed between the dovetail grooves and having a first insertion groove 130 A rotor disk 100 having a seating portion 120, a root portion 240 inserted into the dovetail groove 110, respectively, and a second insertion groove formed on the upper surface of the root portion and facing the first insertion groove ( 230) includes a plurality of buckets 200 having a platform portion 220 is formed.

The rotor disk 100 is composed of a plurality of unit members in which a circular disk is cut in the axial direction. In the drawing, only two unit members of the rotor disk 100 are shown and the rest are omitted. The illustrated two rotor disks 100 are two unit members to which the first bucket 200-1 and the final bucket 200-n are coupled.

A dovetail groove 110 is formed on the circumferential surface of the rotor disk 100, one for each unit member. So, when looking at the entire rotor disk 100, a plurality of dovetail grooves 110 are disposed to be spaced apart from each other along the circumferential direction.

The surface between the plurality of dovetail grooves 110 on the circumferential surface of the rotor disk 100 becomes a platform seating portion 120 on which one side of the platform portion 220 of the bucket 200 is seated. The platform seating portion 120 is formed with a first insertion groove 130 into which the lower portion of the locking key 300 to be described later is inserted when viewed in the circumferential direction.

A plurality of buckets 200 are coupled to the rotor disk 100, respectively. When it is assumed that n buckets 200 are mounted on the rotor disk 100, the first bucket may be referred to as a first bucket 200-1, and the final (last) bucket may be referred to as an nth bucket 200-n.

The bucket 200 includes a root portion 240 inserted into the dovetail groove 110, respectively, and a platform portion 220 formed on the upper surface of the root portion and having a second insertion groove 230 at a position facing the first insertion groove. And, it includes an airfoil 210 extending radially outward and constituting the turbine blade.

Referring to FIG. 4, the second insertion groove 230 may be formed so that the upper portion of the locking key 300 can be inserted into one side of the lower surface of the platform unit 220. The second insertion groove 230 is formed at a position facing the first insertion groove 130. The second insertion groove 230 is formed in a circumferential direction from one side of the platform part 220. The second insertion groove 230 is not continuously formed from one side of the platform 220 to the other side, and a partition wall capable of supporting the locking key 300 in the circumferential direction may exist therein. The partition wall of the second insertion groove 230 may limit the maximum insertion position of the locking key 300.

On the other hand, although not shown, a second insertion groove 230 is also formed on the lower right side of the platform portion 220 of each bucket 200. When assembling the first bucket (200-1) to the n-th bucket (200-n) to the rotor disk 100, the root portion 240 of each bucket 200 to the dovetail groove 110 of the rotor disk 100 The bucket 200 is inserted in the axial direction, and then the locking key 300 is inserted into the insertion space formed by the second insertion groove 230 and the first insertion groove 130 on the right side of the bucket 200. ) Can be fixed so that it does not move in the axial direction.

In the case of the first bucket 200-1, a second insertion groove 230 is formed on the right side of the platform portion 220 and a second insertion groove 230 is formed on the left side of the platform portion 220. Buckets other than the first bucket 200-1 have a second insertion groove 230 formed only on the right side of the platform part 220. Although not shown in the drawing, a second insertion groove 230 is also formed on the right side of the final bucket 200-n.

As shown in Figure 5, in order to fix the final bucket (200-n), the first insertion groove 130 and the second insertion groove (130) to be located on the lower surface of the platform portion 220 of the first bucket (200-1) The locking key 300 is inserted into the insertion space formed by 230).

The insertion space formed by the first insertion groove 130 and the second insertion groove 230 is formed not only in the first bucket 200-1 but also in the lower part of the final bucket 200-n. The insertion space under the first bucket 200-1 and the insertion space under the final bucket 200-n are connected to each other, so that the locking key 300 is slidable in the circumferential direction.

The locking key 300 may be formed in the form of a rectangular parallelepiped that is elongated in the circumferential direction. The locking key 300 may have a chamfer formed on at least some of the corners of the rectangular parallelepiped. In addition, the locking key 300 may have a cylindrical through hole formed in the longitudinal direction at its center. This through hole can reduce the material of the locking key 300, and if a screw is formed on the inner circumferential surface of the through hole, the locking key 300 can be easily removed by inserting a bolt.

When the locking key 300 is pushed under the first bucket 200-1 into the insertion space, the platform part 220 of the final bucket 200-n when the final bucket 200-n is inserted is the locking key 300 ) And do not interfere.

After inserting the final bucket (200-n), the locking key (300) is moved to the insertion space between the final bucket (200-n) and the rotor disk (100). In this case, since there is a gap between the final bucket 200-n and the first bucket 200-1, the locking key 300 can be moved by inserting an awl into the gap. In addition, when the rotor disk 100 is rotated so that the final bucket 200-n goes to the left, the locking key 300 inserted by gravity is slid and moved to the insertion space under the final bucket 200-n. I can.

A fixing sheet 400 is inserted between the first bucket 200-1 and the final bucket 200-n to fix the locking key 300. As shown in Figure 7, the fixing sheet 400 is inserted in a radial direction in the gap between the platform portion 220 of the first bucket (200-1) and the platform portion 220 of the final bucket (200-n) Can be.

In order to form a sufficient gap between the platform portion 220 of the first bucket (200-1) and the platform portion 220 of the final bucket (200-n), the platform portion 220 of the first bucket (200-1) The first concave portion 250 may be formed on the side surface. The first concave portion 250 is formed to a depth greater than or equal to the thickness of the fixing sheet 400.

The fixing sheet 400 may be formed of a rectangular metal plate. The fixing sheet 400 made of a metal plate may be inserted into the first concave portion 250 to support the locking key 300 so that it does not move in the circumferential direction within the insertion groove. In addition, after the fixing sheet 400 made of a metal plate is inserted, a portion protruding to the outside may be easily bent.

It is preferable that a second concave portion 260 is formed on one side of the first bucket 200-1 in the axial direction. After inserting the fixing sheet 400, the bent portion is inserted into the second concave portion 260, so that the fixing sheet 400 does not protrude from one side in the axial direction of the bucket 200 and the platform portion 240 after assembly is completed. Can be avoided.

A method of assembling a bucket for a turbine will be described with reference to FIGS. 4 to 8.

First, the root portion 240 of the first bucket 200-1 is inserted into one of the n dovetail grooves 110 provided in the circumferential direction of the rotor disk 100. The locking key 300 is inserted into the insertion space formed by the right second insertion groove 230 of the first bucket 200-1 and the right first insertion groove 130 of the rotor disk 100, The bucket (200-1) is fixed so as not to move in the axial direction with respect to the rotor disk (100).

Next, the second buckets 200-2 to n-1th buckets 200-n-1 are respectively inserted into the dovetail grooves 110 disposed adjacent to the first bucket 200-1, and a locking key The second bucket 200-2 to the n-1th bucket 200-n-1 are fixed by inserting 300 into the insertion groove. Insert the second bucket (200-2) and insert the locking key (300) into the right insertion groove to fix the second bucket (200-2), and sequentially n-1th bucket (200-n-1) The locking key 300 is inserted until and fixed.

Next, the locking key 300 is inserted into the insertion groove between the first bucket 200-1 and the rotor disk 100. The locking key 300 is inserted in the circumferential direction into an insertion space formed by the first insertion groove 130 of the rotor disk 100 and the second insertion groove 230 of the first bucket 200-1. As shown in FIG. 5, the locking key 300 is completely pushed into the insertion groove under the first bucket 200-1.

Next, the root portion 240 of the n-th bucket 200-n, which is the final bucket, is inserted in the dovetail groove 110 of the rotor disk 100 in the axial direction.

Next, the locking key 300 is moved toward the insertion groove of the n-th bucket 200-n and the rotor disk 100. Locking inserted by gravity by inserting an awl into the gap between the final bucket (200-n) and the first bucket (200-1), or rotating the rotor disk 100 so that the final bucket (200-n) goes to the left The key 300 can be moved by sliding into the insertion space under the final bucket 200-n.

Next, the locking key 300 may be fixed by inserting the fixing sheet 400 into the gap between the first bucket 200-1 and the n-th bucket 200-n. At this time, the first concave portion 250 is formed on the side of the platform portion 220 of the first bucket 200-1, so that a gap is formed between the platform portion 220 of the n-th bucket 200-n do. So, as shown in FIG. 7, it is possible to insert the fixing sheet 400 in the gap in the radial direction until it passes the locking key 300.

Finally, the portion protruding to the outside of the inserted fixing sheet 400 is bent and inserted into the second concave portion 260 formed on one side of the first bucket 200-1 in the axial direction. Accordingly, as shown in FIG. 8, after the assembly is completed, the fixing sheet 400 may not protrude from one side in the axial direction of the bucket 200 and the platform part 240.

9 to 12 are partial perspective views illustrating a process of assembling a bucket to a turbine disk using a bucket fixing device for a turbine according to a second embodiment of the present invention.

The rotor bucket assembly of the turbine according to the second embodiment of the present invention includes a plurality of dovetail grooves 110 disposed to be spaced apart from each other along a circumferential direction, and a platform formed between the dovetail grooves and having a first insertion groove 130 A rotor disk 100 having a seating portion 120, a root portion 240 inserted into the dovetail groove 110, respectively, and a second insertion groove formed on the upper surface of the root portion and facing the first insertion groove ( 230) includes a plurality of buckets 200 having a platform portion 220 is formed.

The rotor disk 100 is composed of a plurality of unit members in which a circular disk is cut in the axial direction. In the drawing, only two unit members of the rotor disk 100 are shown and the rest are omitted. The illustrated two rotor disks 100 are two unit members to which the first bucket 200-1 and the final bucket 200-n are coupled.

A dovetail groove 110 is formed on the circumferential surface of the rotor disk 100, one for each unit member. So, when looking at the entire rotor disk 100, a plurality of dovetail grooves 110 are disposed to be spaced apart from each other along the circumferential direction.

The surface between the plurality of dovetail grooves 110 on the circumferential surface of the rotor disk 100 becomes a platform seating portion 120 on which one side of the platform portion 220 of the bucket 200 is seated. The platform seating portion 120 is formed with a first insertion groove 130 into which the lower portion of the locking key 300 to be described later is inserted when viewed in the circumferential direction.

A plurality of buckets 200 are coupled to the rotor disk 100, respectively. When it is assumed that n buckets 200 are mounted on the rotor disk 100, the first bucket may be referred to as a first bucket 200-1, and the final (last) bucket may be referred to as an nth bucket 200-n.

The bucket 200 includes a root portion 240 inserted into the dovetail groove 110, respectively, and a platform portion formed on the upper surface of the root portion and having a second insertion groove 230 at a position facing the first insertion groove 130 220 and an airfoil 210 extending radially outward and constituting a turbine blade.

In the case of the second embodiment, the dovetail groove 110 of the rotor disk 100 faces downward, and the airfoil 210 of the bucket 200 faces downward. As will be described later, after the locking key 300 is rotated, it is to be in close contact with the second insertion groove 230 of the bucket 200 by gravity.

Referring to FIG. 9, the second insertion groove 230 may be formed so that the upper part of the locking key 300 can be inserted into one side of the upper surface of the platform part 220. The second insertion groove 230 is formed at a position facing the first insertion groove 130. The second insertion groove 230 is formed in a circumferential direction from one side of the platform part 220. The second insertion groove 230 is not continuously formed from one side of the platform 220 to the other side, and a partition wall capable of supporting the locking key 300 in the circumferential direction may exist therein. The partition wall of the second insertion groove 230 may limit the maximum insertion position of the locking key 300.

On the other hand, although not shown, the second insertion groove 230 is also formed on the left upper surface of the platform portion 220 of each bucket 200. When assembling the first bucket (200-1) to the n-th bucket (200-n) to the rotor disk 100, the root portion 240 of each bucket 200 to the dovetail groove 110 of the rotor disk 100 After inserting in the axial direction, by inserting the locking key 300 into the insertion space formed by the second insertion groove 230 and the first insertion groove 130 on the left side of the bucket 200, the bucket 200 ) Can be fixed so that it does not move in the axial direction.

In the case of the first bucket 200-1, a second insertion groove 230 is formed on the left side of the platform portion 220 and a second insertion groove 230 is formed on the right side of the platform portion 220. Buckets other than the first bucket 200-1 have a second insertion groove 230 formed only on the left side of the platform part 220. Although not shown in the drawing, a second insertion groove 230 is also formed on the left side of the final bucket 200-n.

As shown in FIG. 10, in order to fix the final bucket 200-n, the first insertion groove 130 and the second insertion groove 130 so as to be located on the upper surface of the platform part 220 of the first bucket 200-1 The locking key 300 is inserted into the insertion space formed by 230).

The insertion space formed by the first insertion groove 130 and the second insertion groove 230 is formed not only in the first bucket 200-1 but also in the lower part of the final bucket 200-n. The insertion space under the first bucket 200-1 and the insertion space under the final bucket 200-n are connected to each other, so that the locking key 300 is movable in the circumferential direction.

The locking key 300 may be formed in the shape of a rectangular parallelepiped that is elongated in the radial direction. The locking key 300 may have a chamfer formed on at least some of the corners of the rectangular parallelepiped. In addition, the locking key 300 may have a cylindrical through hole formed in the longitudinal direction at its center. This through-hole can reduce the material of the locking key 300, and if a screw is formed on the inner circumferential surface of the through-hole, the locking key 300 can be easily inserted or removed by inserting a bolt.

When the locking key 300 is erected in the insertion space with its longitudinal direction facing the radial direction and pushed in the circumferential direction, under the first bucket 200-1, when inserting the final bucket 200-n, the final bucket 200 The platform unit 220 of -n) does not interfere with the locking key 300.

After inserting the final bucket (200-n), it is rotated so as to span the insertion space between the first bucket (200-1) and the final bucket (200-n) and the rotor disk (100). At this time, since there is a gap between the final bucket 200-n and the first bucket 200-1, the locking key 300 can be rotated by inserting an awl into the gap.

A fixing sheet 400 is inserted between the first bucket 200-1 and the final bucket 200-n and the rotor disk 100 to fix the locking key 300. As shown in FIG. 11, the fixing sheet 400 is in the radial direction of the platform part 220 of the first bucket 200-1 and the platform part 220 of the final bucket 200-n and the rotor disk 100. It can be inserted by lying in the circumferential direction in the gap between the platform seating portions 120 at the ends.

The fixing sheet 400 may be formed of a rectangular metal plate. The fixing sheet 400 made of a metal plate is inserted into the gap between the platform part 220 of the first bucket 200-1 and the final bucket 200-n and the platform seating part 120 of the rotor disk 100. The locking key 300 may be supported so that it does not move in the radial direction within the insertion groove. In addition, after the fixing sheet 400 made of a metal plate is inserted, a portion protruding to the outside may be easily bent.

It is preferable that the first bucket 200-1 and the final bucket 200-n have a stepped portion 280 formed radially outward of the platform seating portion 120 at one end of one side in the axial direction. After inserting the fixing sheet 400, the bent portion is inserted into the stepped portion 280 so that the fixing sheet 400 does not protrude from one side in the axial direction of the bucket 200 and the platform portion 240 after assembly is completed. I can.

A method of assembling a bucket for a turbine will be described with reference to FIGS. 9 to 12.

First, the root portion 240 of the first bucket 200-1 is inserted into one of the n dovetail grooves 110 provided in the circumferential direction of the rotor disk 100. The locking key 300 is inserted into the insertion space formed by the right second insertion groove 230 of the first bucket 200-1 and the right first insertion groove 130 of the rotor disk 100, The bucket (200-1) is fixed so as not to move in the axial direction with respect to the rotor disk (100).

Next, the second buckets 200-2 to n-1th buckets 200-n-1 are respectively inserted into the dovetail grooves 110 disposed adjacent to the first bucket 200-1, and a locking key The second bucket 200-2 to the n-1th bucket 200-n-1 are fixed by inserting 300 into the insertion groove. Insert the second bucket (200-2) and insert the locking key (300) into the right insertion groove to fix the second bucket (200-2), and sequentially n-1th bucket (200-n-1) The locking key 300 is inserted until and fixed.

Next, the rotor disk 100 is rotated so that the dovetail groove 110 of the rotor disk 100 to which the final bucket 200-n is to be assembled is directed downward. In addition, it is assembled in a state in which the air foil 210 of the bucket 200 faces downward. Later, when the locking key 300 is inserted and rotated, the locking key 300 is in close contact with the second insertion groove 230 of the bucket 200 by gravity.

Next, the locking key 300 is inserted into the insertion groove between the first bucket 200-1 and the rotor disk 100. The locking key 300 is a longitudinal direction of the locking key 300 in the insertion space formed by the first insertion groove 130 of the rotor disk 100 and the second insertion groove 230 of the first bucket 200-1. It is inserted in the circumferential direction in this radial direction. As shown in FIG. 10, the locking key 300 is completely pushed into the insertion groove under the first bucket 200-1.

Next, the root portion 240 of the n-th bucket 200-n, which is the final bucket, is inserted in the dovetail groove 110 of the rotor disk 100 in the axial direction.

Next, the locking key 300 is rotated so as to extend radially in the insertion groove between the first bucket 200-1 and the n-th bucket 200-n and the rotor disk 100. Locking key by inserting an awl into the gap between the final bucket (200-n) and the first bucket (200-1) or between the first bucket (200-1) and the n-th bucket (200-n) and the rotor disk 100 300 can be rotated 90 degrees.

Next, the locking key 300 may be fixed by inserting the fixing sheet 400 into the gap between the first bucket 200-1 and the n-th bucket 200-n and the rotor disk 100. At this time, as shown in FIG. 11, the top surface of the platform part 220 of the first bucket 200-1 and the n-th bucket 200-n and the platform seating part 120 of the rotor disk 100 facing the top surface thereof. It is arranged so that gaps are formed at predetermined intervals between them. Thus, the fixing sheet 400 can be laid in the circumferential direction in the gap and inserted until it passes the locking key 300.

Finally, by bending the portion protruding to the outside of the inserted fixing sheet 400, the stepped portion 280 formed on one side in the axial direction of the first bucket 200-1 and the n-th bucket 200-n Insert so that it is seated. Accordingly, as shown in FIG. 12, after the assembly is completed, the fixing sheet 400 may not protrude from one side in the axial direction of the bucket 200 and the platform part 240.

As described above, one embodiment of the present invention has been described, but those of ordinary skill in the relevant technical field add, change, delete or add components within the scope not departing from the spirit of the present invention described in the claims. Various modifications and changes can be made to the present invention by means of the like, and it will be said that this is also included within the scope of the present invention.

1000: gas turbine 1010: housing
1100: compressor 1110: compressor blade
1112: dovetail part 1120: compressor rotor disk unit
1130: compressor cooling air supply channel 1200: combustor
1300: turbine 1320: turbine rotor disk
1322: mating slot
1330: turbine vane 1340: turbine blade
1341: platform unit 1342: root unit
1343: blade unit 1344: film cooling hole
1400: diffuser 1450: fixing nut
1500: torque tube unit 1600: tie rod
100: rotor disk 110: dovetail groove
120: platform seat 130: first insertion groove
200: bucket 210: airfoil
220: platform part 230: second insertion groove
240: root part 250: first concave part
260: second concave portion 280: stepped portion
300: locking key
400: fixed sheet

Claims (20)

A rotor disk having a plurality of dovetail grooves disposed to be spaced apart from each other along the circumferential direction, and a platform seating portion formed between the dovetail grooves and having a first insertion groove;
A plurality of buckets each having a root portion inserted into the dovetail groove and a platform portion formed on an upper surface of the root portion and having a second insertion groove formed at a position facing the first insertion groove;
A locking key positioned on a lower surface of the bucket and inserted in a circumferential direction into an insertion space formed by the first and second insertion grooves in order to fix the final bucket among the buckets assembled on the rotor disk; And
It includes a fixing sheet that is vertically inserted into a gap between the first bucket next to the final bucket and the final bucket, and supports and fixes the locking key from a circumferential side,
The locking key is inserted into the insertion space between the first bucket and the rotor disk, and after inserting the root of the final bucket into the dovetail groove of the rotor disk, the locking key is inserted between the final bucket and the rotor disk. A bucket fixing device for a turbine, characterized in that it is moved into space and fixed so as not to move toward the first bucket by the fixing sheet. delete The method of claim 1,
The locking key is a bucket fixing device for a turbine, characterized in that consisting of a rectangular parallelepiped shape elongated in the circumferential direction. The method of claim 1,
The fixing sheet is a bucket fixing device for a turbine, characterized in that made of a rectangular metal plate. The method of claim 4,
The fixing sheet is a bucket fixing device for a turbine, characterized in that inserted in a radial direction in the first recess formed in the first bucket next to the final bucket. The method of claim 5,
The fixing sheet is a bucket fixing device for a turbine, characterized in that after being inserted into the first concave portion, a portion protruding to the outside is bent and inserted into a second concave portion formed on one side of the first bucket in the axial direction. Inserting a first bucket into one of n dovetail grooves provided in the circumferential direction of the rotor disk, and inserting a locking key into an insertion groove formed between one side of the first bucket and one side of the rotor disk to fix the first bucket. step;
Inserting the second to n-1th buckets into the dovetail grooves disposed adjacent to the first bucket, and inserting a locking key into the insertion groove to fix the second to n-1th buckets;
Inserting a locking key in a circumferential direction into an insertion groove formed between the other side of the first bucket and the other side of the rotor disk;
Inserting the n-th bucket into the dovetail groove;
Moving the locking key toward the insertion groove of the n-th bucket and the rotor disk; And
Including the step of inserting a fixing sheet upright in a radial direction into a gap between the first bucket and the n-th bucket, and supporting and fixing the locking key from a circumferential side,
In the step of inserting the locking key, the locking key includes a first insertion groove formed between the dovetail groove of the rotor disk and a second insertion formed at a position facing the first insertion groove on an upper surface of the root portion of the first bucket. Turbine bucket assembly method, characterized in that inserted into the groove. delete The method of claim 7,
In the step of inserting the fixing sheet, a bucket assembly method for a turbine, characterized in that the fixing sheet is inserted in a radial direction into a first concave portion formed on a side of the platform portion of the first bucket. The method of claim 9,
After the step of fixing the locking key by inserting the fixing sheet,
The method of assembling a bucket for a turbine, further comprising the step of bending a portion protruding to the outside of the inserted fixing sheet and inserting it into a second recess formed on one side of the first bucket in the axial direction. A rotor disk having a plurality of dovetail grooves disposed to be spaced apart from each other along the circumferential direction, and a platform seating portion formed between the dovetail grooves and having a first insertion groove;
A plurality of buckets each having a root portion inserted into the dovetail groove and a platform portion formed on an upper surface of the root portion and having a second insertion groove formed at a position facing the first insertion groove;
A locking key that is positioned on the lower surface of the final bucket to fix the final bucket among the buckets assembled on the rotor disk, and is vertically vertically inserted in the circumferential direction in the insertion space formed by the first and second insertion grooves ; And
A first bucket next to the final bucket, and a fixing sheet laid circumferentially and inserted into a gap between the final bucket and the rotor disk to support and fix the locking key from the inside in the radial direction,
The locking key is inserted into the insertion space between the first bucket and the rotor disk, and after inserting the root of the final bucket into the dovetail groove of the rotor disk, the locking key is the first bucket and the final bucket and the rotor. A bucket fixing device for a turbine, characterized in that it is rotated 90 degrees so as to span the insertion space between the disks and fixed so as not to rotate toward the first bucket by the fixing sheet. delete The method of claim 11,
The locking key is formed in a rectangular parallelepiped shape elongated in a radial direction, and is inserted into the insertion space in a circumferential direction such that a longitudinal direction of the locking key faces a radial direction. The method of claim 11,
The fixing sheet is a bucket fixing device for a turbine, characterized in that made of a rectangular metal plate. The method of claim 14,
The fixing sheet is a bucket fixing device for a turbine, characterized in that lying in the circumferential direction and inserted into a gap between the platform portion of the first bucket and the final bucket and the radial end of the rotor disk. The method of claim 15,
The fixing sheet is a bucket fixing device for a turbine, characterized in that after being inserted into the gap, a portion protruding to the outside is bent radially outward and inserted into a step formed on one side of the first bucket and the final bucket in the axial direction. . Inserting a first bucket into one of n dovetail grooves provided in the circumferential direction of the rotor disk, and inserting a locking key into an insertion groove formed between one side of the first bucket and one side of the rotor disk to fix the first bucket. step;
Inserting the second to n-1th buckets into the dovetail grooves disposed adjacent to the first bucket, and inserting a locking key into the insertion groove to fix the second to n-1th buckets;
Inserting a locking key in a radial direction and in a circumferential direction in an insertion groove formed between the other side of the first bucket and the other side of the rotor disk;
Inserting the n-th bucket into the dovetail groove;
Rotating the locking key by 90 degrees to span the insertion groove between the first bucket and the n-th bucket and the rotor disk; And
Laying and inserting a fixing sheet in a circumferential direction into a gap between the first bucket and the n-th bucket and the rotor disk, and supporting and fixing the locking key from the inside in the radial direction,
In the step of inserting the locking key, the locking key includes a first insertion groove formed between the dovetail groove of the rotor disk and a second insertion formed at a position facing the first insertion groove on an upper surface of the root portion of the first bucket. Turbine bucket assembly method, characterized in that inserted in the circumferential direction in the groove. delete The method of claim 17,
In the step of inserting the fixing sheet, the bucket assembly method for a turbine, wherein the first bucket and the n-th bucket are laid in a circumferential direction and inserted into a gap between a platform portion of the first bucket and a radial end of the rotor disk. The method of claim 19,
After the step of fixing the locking key by inserting the fixing sheet,
The turbine further comprising the step of bending a portion protruding to the outside of the inserted fixing sheet outward in a radial direction, and inserting the first bucket and the n-th bucket into a step portion formed on one side of the axial direction. Bucket assembly method.

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