UA82235C2 - Device for fixation of blades of turbine wheel of axial turbo-machine - Google Patents

Abstract

A device for fixation of blades of turbine wheel of axial turbo-machine has a disc, working blades installed in fir-tree slots of the disc with its tail elements, sealing ring installed in the disc with support by its outer radial collar to rim part of the disc and to tail elements of working blades and connected by inner radial collar to radial collar of the disc directed to long axis. At that the collars of sealing ring and the disc are joined by interrelated, with respective depressions, cylindrical bodies and surrounded by U-like ring with diagonal cut and slot combined with it, interconnected with the lock placed between the disc and U-like split ring. Outer radial collar of the sealing ring is placed in radial-axial holders of tail elements of the working blades. At turned to disc side surface of the inner radial ring of the sealing ring a lug is provided, this is placed in conjugated slot of radial collar of the disc and slot of U-like split ring. At that the lug and cylindrical surfaces of U-like split ring are surrounded by lock as part of ring with C-like cross-section.

Description

Description of the invention

The claimed technical solution relates to gas turbine technology, namely to gas turbine engines, 2 in particular to impellers of axial turbines with fixation of their working blades in the axial direction.

The working wheel of an axial gas turbine is known | see description and figures to the patent of the Russian Federation M1 077 380, cl. IPC GO1O 5/32, publication 21 06.93).

In the longitudinal grooves of its disk, the vanes are fixed from moving along the longitudinal axis of the wheel by a split O-shaped sealing locking ring with a groove along the inner diameter, which covers 70 the side of the disk directed to the axis. The outer diameter of the ring is inserted into the ring groove, which is made up of separate grooves in the blades and is open to the axis of the disc. An insert is installed in the cut of the sealing locking ring, as a fragment of the locking ring of the same O-shaped cross section.

The insert and locking ring are held by the edge of the disk, and its outer diameter enters the annular groove formed by the grooves of the working blades. In the liner and the edge of the turbine disc, connected holes are made, where 12 locking pins are inserted, which hold the liner in the circumferential direction. This device works successfully in turbines of sufficient size.

A known device for securing the blades against axial movement in the wheel of an axial gas turbine | see description and figures to patents - analogues of the General Electric USA MA 171 930, class. NKY 416 - 220K, cl. IPC GO1O 5/30, also France M2 413 543, Germany M2 842 095, Great Britain M2 0120071.

Common to all versions of the known solution is a locking split ring with an O-shaped cross-section, with the open side facing radially from the longitudinal axis of the wheel.

In the variant, which is closest to what it declares in terms of the set of essential features and technical result, a retainer in the form of a part of an O-ring is also installed in the straight groove of the locking ring.

A spring lock in the form of a plate is inserted into the annular groove on the outer side of the side of the sealing ring and the groove on the inner side of one of the walls of the O-shaped retainer. heh)

The known device is not sufficiently technological, especially for the turbine rotors of small-sized engines, where it may be completely impractical due to the need for a proportional reduction of all its constituent parts.

The working wheel of an axial turbomachine is also known | see the description of the patent of the Russian Federation Mo2241834, IPC 7РО10 5/30, application date 12/30/2002, published 12/30/20041. i am

The working vanes according to | (patent of the Russian Federation Mo2241834) in the wheel disc are installed with a stop with the rear end of the shank in the sealing ring from moving backwards, and from moving forward - with a stop of the protrusions of the shanks in the rim of the disc. with

The sealing ring and disc each have radial annular sides. The edges are directed to the longitudinal axis of the wheel and are covered by the walls of the O-shaped retaining ring. For the installation of the retainer, which is fixed with a flat lock, the wall of the MO-cutting ring between the edge of the disc and its web has a through radial groove. co

The groove in its direct projection is combined with a diagonal cut in the other wall of the O-shaped ring. The retainer is made in the form of a plate with the size of a groove, secured by a lock inserted between the disk and the O-ring and bent to the inner diameter of the ring.

The well-known device works successfully and reliably in an aviation turboprop engine of medium power, close to the set task, the set of technical results that are achieved, and the commonality of essential features. with" The described technical solution is adopted as a prototype.

The author took into account the constructive commonality of essential features with the possibility of their improvement and further development of the technical results of the well-known device for fastening blades in the impeller of turbines when solving a more complex task in relation to highly loaded turbines. The difficulty of the task is caused by the fact that in the wheels of highly loaded turbines it is often necessary to install two working blades in each longitudinal groove of the disk. In this way, it is possible to reduce the level of dynamic stresses in the design elements of the blades, in particular, by damping. le The author was given the task of creating such a device for fastening the blades of the impeller of an axial so 20 turbo machine, in which, if necessary, the installation of the blades in pairs in each groove of the disk, with their fixation in the axial direction, would be possible to obtain a certain overall technical result, consisting of several "series of logically interdependent technical results."

The main technical result, as in the prototype, is obtaining a reliable fixation of the blades, but installed in pairs in each groove of the wheel of the turbomachine, which works in conditions of high temperatures and loads from both centrifugal and gas-dynamic forces. o At the same time, it is necessary to ensure the accompanying technical result - due to the optimization of the structure, to increase the strength of its parts. This requirement is also exacerbated, if in each groove of the wheel disk operating in the field of high axial, centrifugal and temperature loads, blades are installed in pairs.

The need for these measures is explained by the fact that in modern turbines, the plane of symmetry of the longitudinal groove, including 60 herringbone, in the disk is usually made at an angle to the axis of rotation, and one blade from the pair in the groove tends to move forward, and the other - back .

In operation, paired blades, making oscillating movements, affect the sealing ring in the circumferential direction, and this effect is much greater than in wheels with single blades.

As the experience of operating such rotors shows, the result of this impact is the displacement of the sealing ring 62 at an angle, which is preceded by the destruction of the elements that fix the ring in the circumferential direction.

In addition, in small-sized turbines, the requirements for manufacturability, assembly and disassembly, as well as for reducing the number of parts are increasing.

Such interdependent technical results, which include, in particular, the prevention of displacement of the seal

Rings in the impeller of an axial turbomachine can be achieved in the following way:

A known device for fastening the blades in the impeller of an axial turbomachine, in which improvements have been made, contains a disk, the working blades are installed in the herringbone grooves of the disk with their shanks, a sealing ring is installed on the disk with a stop with its outer radial edge both in the peripheral part of the disk, and in the shanks working vanes and is connected by its inner radial edge with the radial edge of the disk directed to the 7/o axis, and to fix the sealing ring in the circumferential direction, the mentioned edges of the sealing ring and the disk are articulated by cylindrical bodies in the form of pins interconnected with the corresponding recesses, in addition, these the edges are covered by an O-ring having a diagonal cut and a groove connected to it, interdependent with a lock placed between the disk and the O-ring.

The improvements are as follows:

Fixation of the blades in the axial direction is ensured by the stop of the sealing ring with its outer radial edge in the shafts of the blades and the location of this edge in the radial-axial catches on the shanks of the working blades.

In order to fix the sealing ring in the circumferential direction, its inner radial edge and the radial edge of the disc are articulated by cylindrical bodies, which are bosses, located on the side surface of the inner radial edge of the sealing ring facing 2o of the radial edge of the disc and interconnected with the corresponding notches in the radial edge of the disc , made in the form of semicircular grooves.

In order to fix the O-shaped split ring in the circumferential direction with respect to the disk and the sealing ring, on the side surface of the inner radial side of the sealing ring facing the radial side of the disk, in addition to the mentioned bosses, a protrusion is made. high school

The protrusion is located simultaneously in the combined groove made in the radial side of the disk, in addition to the mentioned semicircular grooves, and the groove of the O-shaped split ring. (8)

Keeping the ends of the split O-shaped locking ring from sagging is carried out with the help of a lock that covers the surface of the mentioned protrusion on the sealing ring and the cylindrical surfaces of the split ring.

At the same time, a fixing sample is made on the inner cylindrical surface of the O-shaped cutting ring, which is divided by the mentioned diagonal cut.

The specified protrusion on the sealing ring is covered by an O-shaped ring inserted between the disk and the middle part of the lock, which is made in the form of a part of the ring with a C-shaped cross section. with

The radially lower end part of the lock is interconnected at the same time with the inner cylindrical surface

MO-shaped cut ring and a fixing sample divided by a diagonal cut on it, and the upper with

Зз5 The end part of the lock covers the jointly indicated protrusion of the sealing ring and facing the disc with the edge of the O-shaped split ring on both sides of its groove.

To increase the manufacturability of assembly-disassembly of the device of the working wheels of small-sized turbines, on the outer radial side of the sealing ring, selections are made between the mentioned radial-axial catches on the shafts of the working blades. "

The claimed technical solution is illustrated by drawings, where: - c - Fig. 1 shows a longitudinal section of the peripheral part of the turbine impeller in assembled form; - Fig. 2 shows a fragment of the turbine impeller in dimetry; c - Fig. 3 shows an enlarged element Г of a cut O-ring in the place of an oblique cut; - Fig. 4 is an enlarged element B, which shows the mutual placement of parts and elements of the section

MO-shaped and sealing rings, as well as a disc in the assembled turbine wheel; so - Fig. 5 shows in dimetry the separate component wheels of the turbo machine, including pairs of working blades, connected to be installed in one common groove of the disc, sealing ring, split O-shaped retaining ring and its lock; c - Fig. b6 shows a fragment of the sealing ring in symmetry from the side of its adjacency to the disc and blades; - Fig. 7 shows one of the variants of the sealing ring, also from the side of adjacency to the disc and the blades; sl - Fig. 8 is a symmetrical image of a part of a split O-shaped retaining ring in the place of a straight groove and a diagonal cut from the side facing the disc; - Fig. 9 shows a dimetrical image of a fragment of an O-shaped sectional locking ring from the side of its inner cylindrical surface with a fixing sample for the deformable lock element; - Fig. 10 is a lock for holding the ends of an O-shaped ring, given in dimetry;

GF) - Fig. 11, 12 - the stages of setting the working blades and the sealing ring in the case of assembling the wheel are shown

Ф with a sealing ring in the variant of its implementation presented in Fig. 6; - Fig. 13, 14, 15, 16 - given stages of installation of working vanes and sealing ring in the case of assembly of a Wheel with a sealing ring in the version of its execution presented in Fig. 7; - Fig. 17 - finally installed working vanes and sealing ring are shown; - Fig. 18, 19, 20, 21, 22 - the stages of installation of the O-shaped cutting ring and the lock that keeps the ends of the cutting ring from sagging are shown.

The working wheel (Fig. 1, 2) of the turbomachine contains the left 1 and right 2 working blades, installed with their 65 herringbone shanks, respectively 3, 4 two in each herringbone groove 5 of the disk 6. Each of the working blades 1, 2 has behind the shanks 3 , 4 radial-axial hooks 7, 8, respectively (Fig. 1, 5).

Behind, with an emphasis on the peripheral part of the disc 6, a sealing ring 9 is installed, which has an outer radial annular edge 10, inserted into the radial-axial catches 7, 8 of the working blades 1, 2, preventing them from moving in the longitudinal direction (Fig. 1, 2, 6, 7).

When performing the sealing ring 9 as in Fig. 7, the outer radial edge 10 is made divided by samples 11 into sections according to the number of pairs of blades 1,2. In the assembled wheel, each such section of the edge 10 is included in a pair of radial-axial catches 7,8 (Fig. 1, 16).

Parallel to the edge 10 is the radial edge 12, which covers the radial-axial catches 7, 8, providing a smooth outer surface of the turbine wheel (Fig. 1). 70 The sealing ring 9 also has an internal radial edge 13 directed radially to the axis of rotation (Fig. 1, 6, 7). On the side surface of the edge 13, facing the disk 6, there are some bumps 14 and one protrusion 15.

On the rim part of the disk 6 there is an annular radial edge 16 directed radially to the axis of rotation. Several semicircular grooves 17 and one wide groove 18 open to the axis of rotation are made on the radial side 16 (see Fig. 5). Grooves 17 in number and angular location are made in accordance with the bosses 14 of the sealing 7/5 Ring 9, and the groove 18 corresponds to the projection 15. The bosses 14 and the projection 15 of the sealing ring 9 installed on the disk 6 are included in the grooves 17 and 18, respectively (Fig. 17).

Moreover, the bosses 14 are inserted into the semicircular grooves 17 with a minimum gap and provide fixation of the sealing ring 9 in the circumferential direction. The dimensions of the groove 18 are chosen to be larger than the protrusion 15 in order to exclude their touching.

Split O-shaped ring 20 (Fig. 8, 9) covers the radial edge 16 of the disk 6 and the inner radial edge 13 of the sealing ring 9 with its vertically directed edges from the common longitudinal axis, outer 21 and inner 22 (Fig. 4, 21). The ring 20 fixes the sealing ring 9 in the longitudinal direction, which, in turn, with the help of the outer radial edge 10 holds the locks 3, 4 of the working blades 1, 2 (Fig. 1).

Split O-shaped ring 20 (Fig. 3, 8, 9) has a narrow diagonal cross-section 23. c

On the inner edge 22 of the ring 20 (Fig. 8, 9), opposite the diagonal cut 23, there is a wide straight groove 24 with sides parallel to the radial plane of the ring 20. (8)

On the inner cylindrical surface of the O-ring 20, a sample 25 is made, divided by a diagonal cut 23 (Fig. 9).

The split O-shaped ring 20 is installed so that the straight groove 24 made on its inner side 22 faces the side of the disk 6, located behind its side 16 (Fig. 19, 20).

The parallel walls of the groove 24 are located on both sides of the protrusion 15 belonging to the sealing ring 9, which passes through the groove 18 of the radial edge 16 of the disc 6 (Fig. 20, element E). This achieves the fixation of the split c ring 20 in the circumferential direction.

The lock 26 (Fig. 10) is a sector that has inner 27 and outer 28 sides, a vertical wall 29 and a part of the ZO that is deformed. co

The wheel assembly (Fig. 1, 21, 22) has a lock 26 located opposite the protrusion 15 of the sealing ring 9 and the groove 24 of the split ring 20.

The lock 26 is wider than the straight groove 24 of the split ring 20, due to which its outer edge 28 covers not only the outer surface of the protrusion 15 of the sealing ring 9, but also the outer surface of the inner edge 22 of the ring 20 on both sides of the groove 24 (Fig. 19, 20 , 21, 22). The inner edge 27 of the lock 26 covers the inner c surface of the split ring 20. In this way, the ends of the split ring 20 are fixed from sagging.

The part 30 of the lock 26 is deformed inside (Fig. 1, 22) in the sample 25 on the inner cylindrical surface of the O-shaped ring 20, thereby ensuring the fixation of the lock 26 in the circumferential direction.

There are two possibilities for assembling the impeller of the turbo machine in terms of fixing the working blades according to the claimed technical solution. They differ in the initial stages of installation of the working blades 1, 2 and the sealing ring 9.

The first possibility is used in the case of a gap between the herringbone groove 5 and the connected herringbone shanks 3, 4 pairs of blades 1.2 more than 0.1mm. z In this case, it would be better to have a wheel with a sealing ring 9 in the variant of execution, as in Fig.b, that is, with a 5p circular outer radial edge 10. The distinctive initial stages of assembling the wheel are presented in Fig. 11, b and 12. Assembly begins with the installation of a pair of working blades 1, 2 with their radial-axial catches 7, 8 sl on the outer radial edge 10 of the sealing ring 9, as shown in Fig.11.

Next, the entire set of working blades 1, 2 is installed in this way and is held together with the sealing ring 9 by a technological device. Blades 1, 2 assembled with a sealing ring 9 are installed in the herringbone grooves 5 of the disk 6 with the kit (see Fig. 12).

The second method of setting the working vanes 1, 2 and the sealing ring 9, shown in Fig. 13, 14, 15,

GF) 16, better for gaps between the herringbone groove 5 of the disk 6 and the connected herringbone shanks 3, 4 of the pair

Ф of blades 1, 2 is less than 0.mm (wheels of small-sized turbines), when simultaneously installing the entire set of working blades 1, 2 in the grooves 5 of the disc b is difficult. In this case, a set of working blades 1, 2 is pre-installed in the herringbone grooves 5 of the disc 6 approximately half the width of the rim of the disc 6 (see Fig. 13).

The sealing ring 9 shown in Fig. 7 with an outer radial edge 10, divided by samples 11 into sections, is installed so that the protruding sections of the edge 10 pass between the radial-axial catches 7, 8 of the herringbone shanks of the working blades 1, 2 (Figs. 14, 15 ). Then the sealing ring 9 is rotated relative to the axis so that each protruding section of the edge 10 is engaged with the radial-axial catches 7, 8 of the pair 65 of the working blades 1, 2 (Fig. 16).

Further stages of assembling the turbine wheel are general and are presented in Fig. 17, 18, 19, 20, 21, 22.

The set of working blades 1, 2 together with the sealing ring 9 are moved to the stop of the sealing ring 9 in the peripheral part of the disk 6 (see Fig. 17). At the same time, the bosses 14 of the sealing ring 9 enter the semicircular grooves 17 in the radial side 16 of the disc 6, without protruding above the surface 19 of the side 16, while

The protrusion 15, having passed through the groove 18, protrudes above the surface 19 of the edge 16.

Installation of the split ring 20 and the lock 26 is shown in stages in Fig. 18, 19, 20, 21, 22. At the same time, the lock 26 is installed on the closing part of the split ring 20, as shown in Fig. 18.

The parallel walls of the straight groove 24 of the ring 20 are located on both sides of the protrusion 15 of the sealing ring 9 (see Fig. 19, 20), which ensures the fixation of the split ring 20 in the circumferential direction. Then, the lock 26 is moved in an arc and is installed opposite the protrusion 15 of the sealing ring 9 (see Fig. 21, 22).

The outer (from the longitudinal axis of the device) edge 28 of the lock 26 covers the outer surface of the protrusion 15 of the sealing ring 9, as well as the outer surface of the edge 22 of the ring 20 on both sides of the straight groove 24, which prevents the lock 26 from falling out. The inner (from the longitudinal axis) edge 27 of the lock 26 covers the inner /5 surface of the ring 20. Part 30 of the lock 26, which is deformed, is placed opposite the sample 25 of the split ring 20. It is deformed inside this sample (see Fig. 22), which ensures the fixation of the lock 26 in the circumferential direction.

The width of the lock 26 is greater than the width of the groove 24 of the split ring 20, which ensures that the outer edge 28 of the lock 26 covers not only the outer surface of the protrusion 15, but also both ends of the split ring 20 along the outer 20 surface of the edge 22.

This, together with the coverage of the lower edge 27 of the lock 26 of the ends of the split ring 20 on its inner surface, ensures reliable fixation of the mentioned ends from sagging.

The turbine wheel is finally assembled (see Fig. 1, 2, 21).

It should also be added that the presence of the edge 12 of the sealing ring 9, which covers the radial-axial attachments c 7, 8 of the herringbone shanks C, 4 working blades 1, 2, as well as the practically smooth outer surface of the split ring 20 minimize ventilation losses. (8)

The design in the production of its parts is technological, and during assembly - disassembly does not cause any difficulties.

The temperature in the inner part of the wheel in operation is 600 degrees Celsius. The greatest stresses are noted in the sealing ring, in the radius of the transition of the centering edge to the vertical wall, but their size does not exceed bZkg/mm2, which is much less than the limits of long-term strength of modern heat-resistant nickel o alloys used for similar parts of turbine rotors. Ha

The high reliability of the declared device at all regular engine operating modes is confirmed by 150-hour tests of a full-size experimental sample of the turbine wheel on an experimental AI 222-25 aviation gas turbine engine. co

Claims (4)

The formula of the invention " 1. The device for fastening the blades of the working wheel of an axial turbomachine, containing a disk, working blades, - in s installed in the herringbone grooves of the disk with their shanks, a sealing ring installed on the disk with a stop with its outer radial edge both in the rim part of the disk and in the shanks working blades, and "z" is connected by its inner radial edge to the radial edge of the disk directed to the longitudinal axis, and the edges of the sealing ring and the disk are articulated by interdependent cylindrical bodies with corresponding notches and are covered by an O-shaped ring with a diagonal cut and a groove connected to it, because interconnected with a lock placed between the disk and an O-shaped split ring, which differs in that the outer radial edge of the sealing ring is placed in the radial-axial engagements of the shanks to the working blades, and on the side surface facing the disk, the specified inner radial edge is made of a sealing the ring is made of a protrusion placed in the connected pa from the radial side of the disc and the groove of the U-shaped split ring, and the protrusion and cylindrical surfaces of the O-shaped split ring are covered by a lock in the form of a part of the C-section ring. sl 2. The device for fastening the blades of the impeller of the axial turbomachine according to claim 1, which is characterized by the fact that the C-shaped lock between the disk and the O-shaped split ring is installed so that its middle part overlaps the protrusion on the inner radial side of the sealing ring on both sides of the O-shaped groove dv of a split ring, made in the side of this ring turned to the disk, while the upper end part of the lock is covered together with the projection and the outer surface of the specified side of the O-shaped split ring on both (Ф) sides of its groove, and the lower end part of the lock is interdependent with the open inner cylindrical with the surface of an MO-shaped cutting ring and a fixing sample made on it, divided by the specified diagonal cut. 60 Z. The device for fastening the blades of the impeller of the axial turbomachine according to claim 1, which is characterized by the fact that the specified cylindrical bodies, with which the radial edge of the disk and the inner radial edge of the sealing ring are articulated, are made in the form of nuts located on the side surface of the inner radial edge of the sealing ring facing the radial edge of the disk , interconnected with the corresponding semicircular grooves in the radial side of the disc. 65 4. The device for fastening the blades of the impeller of an axial turbomachine according to claim 1, which is characterized by the fact that on the outer radial side of the sealing ring, selections are made between the radial-axial catches on