JPH09137702A - Turbine stationary blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make compact a vehicle chamber for surrounding a turbine stationary blade by making small a diameter of a connecting bolt for the turbine stationary blade manufactured by being divided into two upper and lower parts, and to be attached around a rotor, and decreasing the wall thickness of an outer ring through which the bolt is to be inserted. SOLUTION: The wall thickness of a first line stationary blade 1 attaching part is equalized to those of a second line and later stationary blade 2 attaching parts, a seal surface 13 is arranged on the rear end positioned on the final line stationary blade 2 output end, the whole outer peripheral surface is guided into an attaching groove 11, and an outer ring 8 to be pressed under operating fluid on the first line stationary blade 1 input side and a seal fin attaching plate 9 projecting in the axial direction from the rear end of the outer ring 8 and having the large thickness are provided. A bolt 7 for connecting the contact surfaces can be thinned, and the thickness of the outer ring 8 is not necessary to be extremely thickened, and therefore, the thickness from the first line stationary blade 1 attaching part to the final line stationary blade 2 attaching part can be approximately equalized, a turbine stationary blade having a little flexure on a seal part can be formed, turbine efficiency can be improved, and a compact vehicle chamber can be achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has stator vanes, which are arranged inside a turbine casing and which form nozzles for ejecting a working fluid to the rotor blades, arranged all around the annular outer ring and inner ring. Concerning the turbine vane to be installed.

[0002]

2. Description of the Related Art An outer ring that is inserted into a mounting groove that is provided in the interior of a vehicle compartment and positions axially, and a labyrinth packing is attached to the inner surface of the rotor. In a turbine vane in which a vane is arranged between the inner vane for preventing leakage and a nozzle for ejecting a working fluid is formed on the inlet side of a rotor that rotates with a rotor, the turbine vane is
There is an integrated structure in which rows or three rows of stationary vanes are connected and arranged.

Such a turbine vane is composed of upper and lower semi-annular ones, and is a plan view of one side of the joint surface of the lower turbine vane, which is manufactured symmetrically with respect to the axis 016. As shown in FIG. 3, the stationary blades 01, 03 provided on the turbine stationary blade 015 are correctly arranged with respect to the moving blades 02, 04 arranged at the outer periphery of the rotor 014 at intervals in the axial direction. As described above, the outer ring 08 of the lower half turbine stationary blade 015 having the joint surface in a horizontal state is inserted into the mounting groove 011 recessed in the vehicle interior 014 so as to perform axial positioning. ing.

That is, the lower turbine stationary blades 015 are provided on the outer surface of the outer ring 08 by the supports 012 protruding from the outer surface of the outer ring 08.
After being supported by 14, the joint surface of the upper turbine vane (not shown) having a joint surface having exactly the same shape as the structure shown in FIG. 3 is placed on this joint surface, tightened with bolts 07, and joined. , Rotor blades 02 and 04 fixed around the rotor 014
An annular turbine stationary blade 015, in which the stationary blades 01 and 03 are accurately arranged, is arranged on the upstream side of.

The mounting groove 011 provided in the interior of the vehicle interior 014 in the circumferential direction is provided with an inlet portion of the stationary vane 01 in the first row and a second portion.
It is provided in a section that is short in the axial direction between the vicinity of the inlet portion of the stationary vane 03 in the row and has a deeper radial direction. That is, the thickness of the outer ring 08 provided with the mounting portion of the first row stationary blades 01 inserted into the mounting groove 011 is made larger for the reason to be described later, and at the same time as the rear end wall of the mounting groove 011. A seal surface 013 forming a seal portion is provided on the rear end surface of the outer ring 08 having the increased thickness.

The outer ring 08 ', which is provided so as to project from the sealing surface 013 to the wake side and has the mounting portion for the second row stationary vanes 03 on the inner peripheral side, has a wall thickness equal to that of the first row. It is thinner than the blade 01 mounting portion by a thickness substantially corresponding to the depth of the mounting groove 011. Further, an outer ring 08 'provided with a second row stationary vane 03 mounting portion communicates with a rear end of the outer ring 08' and is provided with a second row stationary vane 03 mounting portion. A thinner seal fin mounting plate 09 is provided so as to project in the axial direction.

Further, as described above, the seal ring 05 is provided on the inner peripheral surface of the inner ring 016 which constitutes the inner peripheral portion of the lower turbine stationary blade 015, and the outer peripheral surface of the rotor 010 and the inside of the turbine stationary blade 015 are provided. The leakage of the working fluid from the gap between the circumference is reduced. Furthermore, moving blade 02,
The seal fins 06 are provided on the inner peripheral surface of the outer ring 08 and the inner peripheral surface of the seal fin mounting plate 09 facing the outer peripheral end of 04.
Are planted in a plurality of rows in the axial direction to reduce the leakage of the working fluid from the outer peripheral edges of the moving blades 02, 04.

The main feature of the conventional turbine vane thus constructed is to maintain an optimum seal clearance for the rotor 014 including the rotor blades 02 and 04 under various operating conditions. At the same time, the upper turbine stator vane 015 and the lower turbine stator vane 015 are connected by bolts 07, and the horizontal plane that is the joint surface is tightened to form an annular turbine stator vane 01.
5 is formed, the turbine vane 015
The thermal expansion of can be absorbed in the circumferential direction, the steam leak from the horizontal joint surface can be reduced, and the performance can be improved.

However, the conventional turbine vane 015
Then, (1) since the sealing surface 013 is provided on the outer periphery of the inlet portion of the second row stationary blade 03 for the reason described later, from this sealing surface 013 to the outlet portion of the most downstream second row moving blade 04. The distance becomes longer. Therefore, the seal surface 013 portion and the vicinity of the bolt 07 mounting position closer to the seal surface 013 are 0
A large tensile stress is generated in the outer ring 08 of 20 in the circumferential direction. This means that a large tensile stress is generated in the axial direction of the bolt 07 for tightening the joint surface, and the bolt 07 having a large diameter is required from the viewpoint of securing the strength of the bolt 07. Outer ring 08 to be inserted
Had to be thicker.

(2) On the other hand, the axial width (length) of the outer ring 08 fitted in the mounting groove 011 of the vehicle compartment 010 is
In order to fit as much as possible between the side horizontal plane tightening bolt pitches, the width in the axial direction is shortened so that the inner diameter of the vehicle interior 010 is not increased as much as possible, and the vehicle interior 010 is designed to be compact. There is. Therefore, the second
There is no choice but to reduce the thickness of the outer ring 08 'of the portion where the second row stationary vane 03 is mounted, which increases the deflection of the second row stationary vane 03 as shown by the dotted line in the figure, and the outer ring 0'
The thickness of the seal fin mounting plate 09, which projects from the rear end of 8'to the downstream side in the axial direction, cannot be increased. Therefore, the deformation of the seal fin mounting plate 09 becomes large, the sealing gap at the outer peripheral edge of the second row moving blade 04 tends to increase, the amount of working fluid increases, and the internal efficiency of the turbine decreases, which is not preferable in terms of performance. A condition arises.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems of the conventional turbine vane, the present invention causes a large tensile stress in the bolts for fastening the joining surfaces of the upper and lower turbine vanes. Without making it possible to reduce the diameter of the bolts, the outer ring with the bolts inserted and the joint surface tightened can be made thinner, and the vehicle compartment diameter can be reduced, and the outer ring to which the stationary vanes of the second and subsequent rows are mounted, and The thickness of the seal fin mounting plate that seals the outer peripheral ends of the blades in the second and subsequent rows can be increased, the flexural deformation is reduced, the leakage of working fluid is reduced, and the internal efficiency of the turbine is improved. An object is to provide a turbine vane that can be improved.

[0012]

Therefore, the turbine vane of the present invention has the following means.

(1) The outer ring forming the turbine vane is as follows. (A) Among the stator blades arranged in a plurality of rows in the axial direction, the radial thickness (wall thickness) of the mounting portion for mounting the stator blades from the second row to the final row is set to the first row stator blades. The thickness of the mounting part to be mounted is approximately the same. (B) In order to prevent the leakage of the working fluid that presses the outer peripheral surface of the outer ring between the rear end wall of the mounting groove into which the outer ring is inserted, the sealing surface provided on the rear end surface forming the seal portion is the final row. It was arranged at the exit end of the vane of the eye. (C) The working fluid pressure on the inlet side of the first row vane introduced into the mounting groove provided from the mounting portion of the first row vane to the outlet end of the last row vane applies the radial pressure. The outer peripheral surface to be pressed was provided up to the outlet end of the last row of vanes.

(2) The wall thickness is increased by axially projecting from the inner peripheral portion of the sealing surface, which is protruded inward from the opening of the rear end wall of the mounting groove, to the rearward side to increase the wall thickness. The surface was provided with a seal mounting plate for implanting a seal fin for sealing the outer peripheral edge of the moving blade.

According to the turbine vane of the present invention, the position of the seal surface provided on the outer ring forming the seal portion between the turbine vane and the rear end wall of the mounting groove for mounting the turbine vane to the vehicle compartment is set to the maximum by the above means. The working fluid with the highest pressure at the inlet of the 1st row vane, which was installed in the rear end surface of the outer ring and was introduced into the mounting groove after being shifted to the outlet end of the vane arranged downstream, By acting on the entire outer circumference from the mounting part to the rear end, the outer ring is pressed in the inner circumferential direction, the tensile stress applied to the bolt is reduced, the bolt size is reduced, and the outer ring thickness of the bolt mounting part can be reduced. Therefore, the mounting groove into which the outer ring is inserted can be made shallow, and the passenger compartment diameter can be made compact.

Further, the thickness of the outer ring of the bolt mounting portion can be reduced, and the compactness of the passenger compartment diameter is not hindered.
By installing the mounting groove up to the stationary blade outlet of the last row, 1
The outer ring for mounting the stationary vanes in the first row to the last row can be made to have the same thickness, and the bolt mounting portion, especially the bolt mounting portion on the wake side can be moved to the outer periphery of the mounting portion of the final row stationary blade.
As a result, the flexural deformation of the final row stationary vanes can be reduced. Also, by making the mounting groove shallow, the seal fin mounting plate that projects in the axial direction from the rear end of the outer ring can have a large wall thickness without increasing the passenger compartment diameter.
This also makes it possible to reduce the flexural deformation.

As a result, the leak amount of the working fluid from the seal portion can be reduced, and the turbine performance can be improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a turbine vane of the present invention will be described below with reference to the drawings. FIG. 1 is a partial plan view of a joint surface showing a first embodiment of a turbine vane of the present invention.

As shown in the figure, on the outer circumference of the rotor 14, rotor blades 2 and 4 which are planted over the entire circumference are arranged in two rows in the axial direction at intervals so as to rotate together with the rotor 14. Has been On the upstream side of each of the moving blades 2 and 4, the stationary blades 1 and 3 are arranged to pass the working fluid F to the moving blades 2 and 4.
4 is jetted to the inlet side to operate the moving blades 2 and 4.

The stator vanes 1 and 3 are provided with an inner ring 16 on the inner peripheral surface of which a seal ring 5 for preventing the leakage of the working fluid F from a gap formed between the outer peripheral surface of the rotor 14 and the inner ring 16 is installed. Room 1
0 is inserted into a mounting groove 11 provided on the inner peripheral surface of the rotor blade 0 to position the stationary blades 1 and 3 in the axial direction, and
Is disposed in the circumferential direction between the outer ring 8 and the outer ring 8 on which the seal ring 6 for preventing the leakage of the working fluid from the gap formed between the inner ring 16 and the outer ring 8 is formed. The turbine vane 15 is configured.

The turbine vane 15 is manufactured in the form of a semi-circular ring divided into upper and lower parts. When the turbine vane 15 is mounted on the outer peripheral surface of the rotor 14, the outer ring 8 of the lower turbine vane 15 is fitted into the mounting groove 11 as described above. After being inserted, the support 12 provided on the outer peripheral surface of the outer ring 8 is fitted into the groove provided in the lower half portion of the vehicle compartment 10 to be integrated with the vehicle compartment 10, and then the joining surface of the turbine vane 15 above. Is placed on the joint surface of the turbine vane 15 below and by the bolt 7 inserted through the outer ring 8,
By tightening, an annular turbine stationary blade 15 is formed on the outer circumference of the rotor 14 and the moving blades 2, 4.

Here, a mounting groove 11 into which the outer ring 8 is inserted
Has a large width in the axial direction. That is, for reasons to be described later, the wall thickness of the outer ring 8 where the bolt 7 is inserted can be reduced, and the radial depth of the mounting groove 11 into which the outer ring 8 is inserted can be reduced, thereby increasing the diameter of the vehicle interior 10. Without moving the first row vane 1 from the inlet of the second row vane 3
Can be provided up to the outlet of the outer ring 8 and can accommodate the entire width of the outer ring 8 in the axial direction.

When the outer ring 8 is inserted into the mounting groove 11, a minute gap 18 is formed between the front end wall of the mounting groove 11 and the front end face of the outer ring 8, and the stationary vanes 3 of the second row are The rear end wall of the mounting groove 11 located at the outlet and the seal surface 13 provided on the rear end surface of the outer ring 8 are closely contacted with each other to prevent outflow of the working fluid introduced into the outer peripheral surface of the outer ring 8 described later. Form a sealing part to prevent. As a result, under the high pressure working fluid on the inlet side of the first row vane 1 flows into the outer peripheral surface of the outer ring 8 inserted into the mounting groove 11 through the gap 18, and acts on the outer peripheral surface of the entire length of the outer ring 8, The outer ring 8 can be pressed in the inner peripheral direction. Due to the pressurization of the outer ring 8 in the inner circumferential direction, the joining surface between the upper turbine stationary blade 15 and the lower turbine stationary blade 15 is
A huge joining force can be generated.

A seal fin mounting plate 9 is provided so as to project from the inner peripheral side of the rear end surface of the outer ring 8 on which the seal surface 13 is formed to the rear flow side. This seal fin mounting plate 9
Is made thin because the mounting groove 11 is made shallow and the thickness of the outer ring 8 of the mounting portion of the second row vane 3 is made equal to the thickness of the mounting portion of the first row vane 1. The thickness can be increased and the rigidity is increased. By increasing the thickness, the deflection of the seal fin mounting plate 9 can be reduced.

The turbine vane of this embodiment has the above-mentioned structure, and the seal surface 13 of the outer ring 8 which comes into contact with the rear end wall of the mounting groove 11 is provided at the most downstream of the outlet end of the second row vane. In other words, the mounting groove 11 recessed in the circumferential direction is formed on the inner peripheral surface of the vehicle interior 10.
Is provided from the inlet end of the first row vane 1 to the outlet end of the second row vane 3 so that the entire axial width of the outer ring 8 can be inserted. The working fluid F on the inlet side of the first row stationary vanes 1 having a high pressure is introduced from the gap 18 and guided to the entire outer peripheral surface of the outer ring 8 to act as an external pressure.

As a result, the upper and lower turbine vanes 15
It is possible to significantly reduce the tensile stress applied to the bolt 7 by making the joint surface of (1) act on the compressive stress side and suppress the deflection of the outer ring 8 of the attachment portion of the second row stationary vane 3. That is, the bolts 7 used for fastening and joining the joint surfaces of the upper and lower stationary blades 15 do not function as a strength member, but merely fix the upper and lower stationary blades 15 so as not to move. Since the bolt 7 stress does not occur, the bolt 7
Size can be reduced.

As a result, the size of the bolt 7 can be made smaller, the thickness of the outer ring 8 through which the bolt 7 is inserted can be reduced, and the mounting position of the bolt 7 through which the outer ring 8 is inserted is close to the rear end of the outer ring 8 in the second row. It can be the outer circumference of the stationary blade 3. This not only makes it possible to design the outer ring thickness to be compact, but also to design the passenger compartment to be compact, and improves the requestability of bolt tightening on the passenger compartment side.

Further, since the thickness of the outer ring 8 can be reduced, the mounting groove 11 into which the outer ring 8 is inserted can be made shallow. Therefore, the seal fin 6 for sealing the outer peripheral edge of the second row moving blade without increasing the inner diameter of the vehicle interior 10 The seal mounting plate 9 can be made thicker, and the sealing surface 13 of the outer ring 8 is provided at the outlet of the second row stationary vane 3 so that the outer ring 8 on which the second row stationary vane 3 is mounted has a meat portion. Can be added and the wall thickness can be increased to reduce the deflection of the outer ring 8 of the second row stationary vane 3 mounting portion, reduce the deformation of the seal fin mounting plate 9, and prevent the increase of the seal clearance. The performance can be improved by reducing the amount of leak from the seal portion.

Next, FIG. 2 is a partial plan view of a joint surface showing a second embodiment of the turbine vane of the present invention. As shown in the figure, in the present embodiment, in addition to the two connected stationary blades shown in the first embodiment, the stationary blades 19 in the third row for ejecting the working fluid F to the moving blades 19 in the third row are also integrated. The rigidity is further strengthened by using 3 connected vanes.

Further, the axial direction of the outer ring 8 can be made sufficiently large,
Since the pressing force generated on the joint surface by the working fluid F acting on the outer peripheral surface of the outer ring 8 can be further increased, 1
The outer ring 8 provided with the mounting portion for the row vane 1 has a mounting groove 11
It was installed in front of. Also in the turbine vane 15 of the present embodiment, the effects obtained in the first embodiment described above are effective in that they sufficiently function in addition to the effects described above.

[0031]

As described above, according to the turbine vane of the present invention, the following effects can be obtained with the configuration shown in the claims.

(1) The working fluid having the highest pressure on the inlet side of the first row vane is guided to almost the entire outer circumference of the outer ring, and is acted as an external pressure on the outer ring to form the turbine vane joint surface divided into upper and lower parts. By acting as a compressive force and suppressing the deflection of the mounting portion of the stationary vane from the second row onward, it is possible to greatly reduce the tensile stress generated near the joint surface tightening bolts.
Bolts do not serve as strength members, but above
It serves only to fix the lower ring so that it does not move, and the size of the bolt can be reduced. As a result, not only can the outer ring thickness be designed compact, but the passenger compartment can also be designed compact, and the demand for tightening bolts on the passenger compartment side can be improved.

(2) Further, by increasing the rigidity of the stationary blade mounting portion in the second and subsequent rows without impairing the compactness of the passenger compartment, it is possible to reduce the deflection amount of the second row stationary blades. The amount of deformation of the seal mounting plate of the second row moving blade can be greatly reduced, the amount of leakage from the seal portion can be reduced, and the performance can be improved.

[Brief description of the drawings]

FIG. 1 is a partial plan view of a joint surface showing a first embodiment of a turbine vane of the present invention,

FIG. 2 is a partial plan view of a joint surface showing a second embodiment of a turbine vane of the present invention,

FIG. 3 is a partial plan view of a joint surface showing a conventional turbine stationary blade.

[Explanation of symbols]

 1 1st row stationary blade 2 1st row stationary blade 3 2nd row stationary blade 4 2nd row stationary blade 5 Seal ring 6 Seal fin 7 Bolt 8 Outer ring 9 Seal fin mounting plate 10 Cabin 11 Static blade mounting groove 12 Static blade Support support 13 Sealing surface 14 Rotor 15 Turbine stationary blade 16 Inner ring 17 Shaft center 18 Gap 19 Third row stationary blade 20 Third row moving blade

Claims (1)

[Claims] 1. A stationary vane arranged in the circumferential direction is axially arranged in two or more rows between a semi-circular inner ring and an outer ring, which form a circular ring by tightening and joining horizontal planes with bolts. , The outer peripheral edge portion of the outer ring is inserted into a mounting groove recessed in the circumferential direction of the vehicle interior,
In the turbine vane mounted on the outer circumference of the rotor, the wall thickness of the mounting portions of the second and subsequent rows of the vanes is substantially equal to the wall thickness of the mounting portion of the first row of the vanes, and A sealing surface forming a seal portion with the end wall is provided at a rear end arranged at the stationary blade outlet end of the final row, and the inlet of the stationary blade of the first row introduced into the mounting groove. An outer ring having an outer peripheral surface up to the rear end that receives a pressure force in the radial direction by the side working fluid, and a seal fin mounting plate that projects from the inner peripheral part of the sealing surface to the downstream side. Turbine vanes characterized by.