KR20070022593A - Containment safety device for turbomachinery with radially perfused compressor wheel - Google Patents

Abstract

The invention relates to a turbomachine having a compressor wheel (3) flowing radially through. The compressor housing 8 is formed of an outer helical housing 10 and an inner housing insert 12. By aging, the compressor wheel 3 can be broken. In the ideal case, for the containment safety of the turbo machine, the fragments should be caught by the housing insert 12. Due to the force released in impact form by the impacting debris of the compressor wheel 3, the invention provides a special configuration of the inner housing insert 12, in particular as a substitute, so that the debris can be reliably and inexpensively turbomachined Can be supported within. That is, the containment safety of the turbo machine is guaranteed.

Compressor wheel, turbo machine, compressor housing, outer spiral housing, inner housing insert.

Description

CONTAINMENT-SECURING DEVICE FOR TURBO MACHINE WITH RADIAL FLOWED THROUGH COMPRESSOR WHEEL}

1 is a partial longitudinal cross-sectional view of a radial compressor with a housing insert, as used in the prior art.

2 is a partial longitudinal sectional view of the radial compressor according to the invention at the connection point between the housing insert and the helical housing;

3 is an enlarged view of a portion of the housing insert facing the compressor wheel.

4 is a top view of a ring web of the housing insert.

* Description of the symbols for the main parts of the drawings *

1: bearing housing 2: shaft

3: compressor wheel 4: hub

5: blade 6: outer contour

7, 13: inner contour 8: compressor housing

9: flow channel 10: spiral housing

11, 14: channel section 12: housing insert

15: Inner cylinder 16: cavity

17, 18: fixing part 19: wall

20: peak 21: gap

22: fixing screw 23: elastic groove

24: cross section 25, 26: rib

27: Web 28: Home

29: air passage channel 30: housing

The present invention relates to a turbo machine with radially flowing compressor wheels and a housing insert for assembly in the turbo machine.

Since the basic construction and manner of operation of the radial compressor of such a turbomachine, such as a turbocharger, are well known, they are not described in further detail here. EP 1 233 190 A1 discloses a turbo machine with a compressor wheel radially perfused.

After long operation under unfavorable operating conditions, the compressor wheel of the turbomachine is very weak by corrosion, erosion and aging, so that the rupture of the compressor wheel cannot be ruled out. In case of compressor failure in which the wheel is broken into at least two or three large parts, the individual parts are blown out by a large centrifugal force. In this case, the debris can be discharged from the compressor housing. The compressor wheel blade is completely destroyed and the remaining hub body is sandwiched between the bearing housing and the compressor housing. Wedge action takes place by the design of the hub, which applies a large axial force in the form of impact to the housing. Debris of the compressor wheel may drain other machine parts from the turbo machine, which can cause severe damage. As a result, in case of damage the containment safety of the entire turbomachine is lowered, which must be avoided.

In order to ensure the containment safety of the turbomachine without additional burst protection means external to the helical housing, EP 1 233 190 A1 proposes to form the compressor housing in two parts from the outer helical housing and the inner housing insert. The inner housing insert is mounted to the outer helical housing by a flexible fixture. The flexible fixture used to secure the housing insert to the helical housing is formed more securely to breakage than the rigid fixture of the outer helical housing of the compressor housing, ie the bearing housing of the turbo machine. For this reason, the prior art according to EP 1 233 190 A1 provides a helical housing which can reliably prevent the discharge of debris or partial pieces of the ruptured operating wheel. The kinetic energy of the fragments of the ruptured compressor wheel can be completely converted into strain energy and heat inside the turbomachine.

However, in turbomachines according to EP 1 233 190 A1 a complex and costly fixing between the housing insert and the helical housing is required.

It is an object of the present invention to provide a turbo machine with radially perfused compressor wheels that can be manufactured at low manufacturing costs, ensuring high containment safety. In addition, the housing insert provided as a replacement should be easily mountable.

The object is achieved by a turbo machine and housing insert having radially perfused compressor wheels according to the independent claim of the present invention. The dependent claims present preferred embodiments of the invention.

According to the invention, there is provided a turbo machine with radially flowing compressor wheels, wherein the outer helical housing and the inner housing insert form a compressor housing. The housing insert forms an air passage channel, and at the first end of the housing insert which lies in the air inlet of the air passage channel, fastening means are provided for securing the housing insert to the helical housing. The fastening means can be formed in the form of a hole, for example. At the second opposite end of the housing insert is provided a support device. If the compressor wheel ruptures, fragments of the compressor wheel fly towards the inner housing insert. The force of the individual debris released in this case, in particular centrifugal action, is converted by the support device according to the invention into pressures acting axially and radially on the outer helical housing. The pressure causes the inner housing insert to fit within the outer helical housing.

According to a preferred embodiment the support device is pressed radially outwardly mainly or partly by means of a burst compressor wheel for fixation in the helical housing. As a result, the force released results in the deformation of the inner housing insert in the deformation section upon breakage of the compressor wheel. This modification causes the inner housing insert to fit within the outer helical housing of the turbo machine. In order to structurally convert the clamping action, a special deformation section is provided, on the one hand, whereby the energy released by the rupture of the compressor wheel is converted as much as possible into the deformation energy, on the other hand, the helical housing and the housing insert In a manner defined by the support device. However, the deformation section may be provided only in the outer helical housing.

In an embodiment of the invention the helical housing is provided with a fixing device in the form of a groove, for example in which the support device of the housing insert is fitted. The fixing device is formed such that its breakdown is excluded by the force released in the form of an impact.

The combination of jamming and deformation enables efficient absorption of the emitted energy and the conversion of the released energy into strain energy and heat energy. This results in a decisive advantage over the prior art for the containment safety of turbomachines. If the position of the inner housing insert changes upon rupture of the compressor wheel, the housing insert stays in the same place within the outer helical housing. Thus, as a result, fragments of the compressor wheel do not leave the interior of the turbo machine and no other part of the turbo machine is blown out of the turbo machine by the impact force.

According to a preferred embodiment of the invention, the support device is formed on the outer surface of the housing insert in the form of a ring web. The grooves in the outer helical housing form a fixing device. The groove is provided on the side of the helical housing facing the housing insert. When the compressor wheel is broken, the ring-shaped web is pressed outward from the outer surface of the housing insert and fits in the groove of the helical housing. The webs and grooves are positively fitted and all forces released by breakage of the compressor wheel are released through the helical housing if not previously converted to deformation and thermal energy.

According to another preferred embodiment of the present invention the ring-shaped web extends parallel to the central axis of the housing insert, the free end of the web pointing in the direction of the air inlet opening and only towards the outside for fixation by rupture of the compressor wheel. Is pressed into the groove of the helical housing.

According to this embodiment it is possible to assemble the inner housing insert into the outer helical housing without difficulty. Because the ring-shaped web forms a flat extension of the outer circumferential section of the housing insert used for positive assembly to the helical housing. Thus, it is possible to disassemble the housing insert without having to disassemble the helical housing. This is particularly desirable because the housing insert is a substitute, for example, worn out due to erosion, which must sometimes be replaced. Therefore, the turbo machine according to the present invention can be maintained easily and inexpensively.

Due to the design of the housing insert on the inner side, ie on the side facing the compressor wheel, the ring-shaped web is pressed into the groove for fixation only when the compressor wheel ruptures. This configuration is advantageous in that, compared to bayonet connections, a housing insert with a web that is not parallel to the center axis of the housing insert can be assembled into the spiral housing because no milling grooves are provided in the longitudinal direction of the spiral housing. .

According to another preferred embodiment of the present invention, the ring-shaped web has one or more elastic grooves. The elastic groove makes it possible to control the radial deformation of the ring web. The ring-shaped web bends into the groove of the helical housing upon rupture of the compressor wheel, thereby changing the cross section of the ring-shaped web. By forming elastic grooves at regular intervals on the circumference of the ring web, the ring web can be bent without affecting other segments of the web subdivided by the elastic grooves. The elastic grooves are preferably passage grooves that extend into the material from the free end of the web.

According to another preferred embodiment of the invention the inner housing insert comprises at its outer surface one or more transfer members, for example in the form of ribs, for the transfer of force from the inner contour of the housing insert to the web. Rather than the rupture of the compressor wheel deforming the housing insert, the transfer member is provided between the web and the outer surface of the housing insert in the axial direction of the housing insert in order to press the web into the groove of the outer helical housing in a defined manner. . Preferably the delivery member lies vertically on the ring web and forms a bridge between the web and the portion of the housing insert facing the compressor wheel. The transfer members are preferably evenly distributed in the web, so that each web section formed by the elastic groove is provided with one or more transfer members.

According to another preferred embodiment of the invention, the groove is formed in the deformation section in the outer helical housing. As the deformation section, a rib of the helical housing can be used, so that part of the outer helical housing, ie the rib itself, can be deformed when engaged into the rib of the helical housing, so that the energy of the burst compressor wheel can be converted into strain energy. In addition, if more ribs are provided by the above measures, the weight of the helical housing is reduced.

In the non-rotating parts referred to in the present invention, materials having a breaking elongation of at least 5% are used.

Hereinafter, with reference to the accompanying drawings an embodiment of the present invention will be described in detail.

1 shows a partial longitudinal cross-sectional view of a radial compressor according to the prior art. The exhaust gas turbocharger based on the drawing has a shaft 2 supported in the bearing housing 1 in its intermediate longitudinal region, the shaft being not shown here at the end protruding above the bearing and in the drawing. Supports radially perfused compressor wheel 3 as schematically shown in FIG.

The compressor wheel 3 shown has a hub 4 received in a rotational connection on a shaft 2 driven by a turbine wheel. The hub 4 has a blade 5 protruding radially around. The outer contour 6 of the hub 4 together with the inner contour 7 of the compressor housing 8 defines an outwardly narrowing flow channel 9 which is deflected from the axial direction A to the radial direction B. Form. The cross section of the flow channel corresponds to the configuration of the blade 5. The compressor housing 8 is fixed to the bearing housing 1 by the rigid fixing part 18. The diameters of the hub 4 and the blade 5 increase from the flow inlet toward the flow outlet, resulting in a large mass distribution over the length of the compressor wheel 3.

The compressor housing 8 consists of an outer helical housing 10 and an inner housing insert 12 fixed to the bearing housing by a rigid fastening 18. The helical housing 10 comprises a channel section 11 of the flow channel 9 facing outward in the radial direction B. The housing insert is provided in radial direction B between the helical housing 10 and the compressor wheel 3, the inner contour 13 of which is combined with the outer contour 6 of the hub 4 of the compressor wheel 3. It forms the channel section 14 of the flow channel 9 extending substantially in the axial direction A.

FIG. 2 shows a section of a helical housing modified in accordance with the present invention, and the prior art housing insert shown in FIG. 1. The fixing part 17 of FIG. 1, which has been realized by a complicated and expensive screw configuration, can be omitted and replaced by a fixing screw 22 of DIN standard. The housing 30 of the housing insert is mounted with a ring-shaped web 27 that extends parallel to the longitudinal central axis of the housing insert. The ring web 27 is again supported by the ribs 25 in the circumferential direction, which ribs are used for force transmission from the inner contour towards the compressor wheel 3 to the ring web.

Ribs 26 are provided in the helical housing 11 that deform upon engagement of the ring-shaped web. Ribs in the helical housing have grooves 28, which are deformed as the ring-shaped web 27 deforms when the compressor wheel 3 ruptures in the grooves 28, so that the housing insert as a whole is appropriately braked and in the helical housing. To be supported. The shape of the groove is selected so that the groove is not broken, but the profile of the force in the preferably deformable rib of the helical housing is such that the force created by the rupture of the compressor wheel can be absorbed by the helical housing.

FIG. 3 shows part X of FIG. 2, ie the ring shaped web 27 of the housing insert 12. 4 shows the top view of FIG. 3. 4 shows an elastic groove 23 extending into the material from the free end of the web. The elastic groove completely separates the ring-shaped web so that individual segments of the ring-shaped web divided by the elastic groove can be bent upwards.

In a turbomachine with a radially flowing compressor wheel according to the invention, even if the compressor wheel is damaged by aging, the fragments are reliably and inexpensively provided, especially by providing a special configuration of the inner housing insert which is provided as a replacement. It can be supported in a turbo machine. That is, the containment safety of the turbo machine is guaranteed.

Claims (15)

Radially flowing compressor wheel (3), which is received on a shaft (2) supported in a bearing housing (1) and in a compressor housing (8) with a flow channel (9) Disposed, the outer contour 6 of the hub 4 of the compressor wheel 3 and the inner contour 7 of the compressor housing 8 form a flow channel 9 deflected axially from the axial direction, The compressor housing 8 has at least one outer helical housing 10 and an inner housing insert 12, the housing insert 12 forming an air passage channel 29, the In a turbomachine, the first end of the housing insert (12), which lies in the air inlet, is provided with fixing means for securing the housing insert (12) to the helical housing (10). At the second opposite end of the housing insert 12 a support device 27 is provided, and in the event of a rupture of the compressor wheel 3 the inner housing insert 12 is routed through the support device 27 to the outer helical housing. Turbo machine having a radially perfused compressor wheel, characterized in that it is formed to fit in the outer helical housing (10) by the pressure exerted on (10). The radially flow-through compressor wheel according to claim 1, characterized in that the support device (27) is pressed radially outwardly by the burst compressor wheel (3) for fixing in the spiral housing (10). Turbo machine with a gun. The outer helical housing (10) according to claim 1 or 2, wherein the outer helical housing (10) and the inner housing insert (12) are caught by the rupture of the compressor wheel (3). Turbo machine with a radially perfused compressor wheel, characterized in that a fixing device is provided for supporting. The outer spiral housing 10 and / or the inner housing insert 12 at least partially modify the energy released upon rupture of the compressor wheel 3. Turbo machine with a radially perfused compressor wheel, characterized by having deformation sections (25, 26) for conversion to energy. 5. The support device 27 according to claim 1, wherein the support device 27 is a ring-shaped web on the outer surface of the housing insert 12, and the fixing device 28 is the outer spiral housing 10. 6. A turbo machine with radially flowing compressor wheels, characterized in that it is a groove within. 6. The ring-shaped web 27 extends substantially parallel to the central axis of the inner housing insert 12 and is subject to deformation of the web 27 by rupture of the compressor wheel 3. Turbo machine with a radially perfused compressor wheel, characterized in that it is pressed into the groove (28) for fixing by and / or by another part of the housing insert (12). 7. Compressor radially perfused according to claim 5 or 6, characterized in that the ring-shaped web (27) has at least one elastic groove (32) to enable radial deformation of the web (27). Turbo machine with wheels. 8. The inner housing insert 12 according to any one of the preceding claims, wherein the inner housing insert 12 has at least one transfer member 25 on the outer surface for force transmission from the inner contour 13 to the web 27. A turbo machine having a radially perfused compressor wheel, characterized in that it comprises. 9. The compressor wheel as claimed in claim 5, wherein the groove 28 is provided in the deformation section 26 of the outer helical housing 10. Turbo machine. 10. Turbomachined machine according to any one of the preceding claims, characterized in that the deformation section is formed in the form of ribs (26) of the outer helical housing (10). . As a housing insert 12 for mounting in a spiral housing 10 as an internal part of a compressor housing 8 of a turbomachinery having a radially perfused compressor wheel 3, the housing insert 12 is viewed in cross section. A tubular housing 30 which is open at both sides with an inner space, the inner space forming an air passage channel 29, the outer surface of the housing 30 being positively mounted in the helical housing 10. Fastening means for fastening the housing insert 12 to the helical housing 10 at the first end of the tubular housing 30, which is formed for the purpose, and which lies in the air inlet of the air passage channel 29. In the housing insert provided, At the second opposite end of the housing 30, the support device 27 is pressurized so that the support device 27 is pressed outward in the radial direction by the burst compressor wheel of the turbomachine for fixing in the helical housing 10. 27) is formed. 12. The housing insert according to claim 11, wherein the support device is a ring shaped web (27) on an outer surface of the housing (30). 13. The housing insert of claim 12, wherein the ringed web (27) extends substantially parallel to the central axis of the tubular housing (30). 14. Housing insert according to claim 12 or 13, characterized in that the ring-shaped web (27) has at least one elastic groove (32) in the axial direction to enable radial deformation of the web (27). . 15. The housing insert according to claim 12, wherein the housing insert 12 is at least one for transmitting force from an inner contour 13 to the web 27 on the outer surface of the housing insert 12. And a delivery member (25), the delivery member (25) lying vertically on the web (27).

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