CN215860349U - Turbine engine and low-pressure shaft failure protection assembly thereof - Google Patents

Abstract

The low-pressure shaft failure protection assembly is arranged at a rear bearing assembly of the low-pressure turbine component, the low-pressure turbine component comprises a rotor assembly and a stator assembly, the low-pressure shaft failure protection assembly comprises a first limiting assembly and a second limiting assembly, the first limiting assembly comprises a first limiting part arranged on the rotor assembly and a third limiting part arranged on the stator assembly, and the second limiting assembly comprises a second limiting part arranged on the rotor assembly and a fourth limiting part arranged on the stator assembly. The first limiting piece and the third limiting piece are provided with a first initial gap along the axial direction of the engine, the second limiting piece and the fourth limiting piece are provided with a second initial gap, and the first initial gap and the second initial gap are both smaller than the axial distance between the rotor assembly and the stator assembly at any position in the low-pressure turbine part. A turbine engine is also provided.

Description

Turbine engine and low-pressure shaft failure protection assembly thereof

Technical Field

The utility model relates to a turbine engine and a low-pressure shaft failure protection assembly thereof.

Background

The over-rotation event of the low-pressure rotor system of the aircraft engine seriously threatens the flight safety of the engine and the aircraft. For dual rotor aircraft engines, the consequences of low pressure rotor system over-rotation due to low pressure shaft failure events caused by over-torquing, resonance, fatigue, corrosion, material defects, and manufacturing errors are most severe. When the failure event occurs to the low-pressure shaft of the aircraft engine, the fan and booster system and the low-pressure turbine system are decoupled instantly, the low-pressure turbine loses the driving load, meanwhile, the response of other components such as an engine fuel control component, an adjustable mechanism and a control valve is delayed, the rotating speed of the low-pressure turbine component is increased rapidly under the driving of inertia force and residual high-energy gas in a flow channel, the low-pressure turbine disk is broken under severe conditions, the broken turbine disk is further punched through an engine casing, and the safety of an airplane is threatened to cause a hazardous result.

Therefore, the civil aviation authorities at home and abroad clearly propose that the aircraft engine needs to ensure the flight safety under the over-rotation event in airworthiness regulations, and each aeroengine manufacturer must add the over-rotation protection function during the engine design. The mature foreign engine model adopts the control type and mechanical low-pressure shaft failure protection design.

The control type low-pressure shaft failure protection design is that a rotating speed sensor and the like are used for monitoring the real-time rotating speed of a low-pressure shaft, and once the rotating speed of the low-pressure shaft is detected to be abnormal, an engine control system sends an oil cutting and related adjustable mechanism actuating instruction to enable a low-pressure turbine rotor to lose power, so that dangerous events such as over-rotation and the like are avoided. However, the failure protection design may cause the situation that the power of the engine is lost under the normal working condition due to the false monitoring of the sensor, so that the flight safety is threatened; and the control signal has certain hysteresis, and the residual high-energy gas and inertia force in the flow passage can still cause the low-pressure turbine rotor to generate an over-rotation event.

The mechanical low-pressure shaft failure protection design is that a rotor-stator collision grinding structure is designed in a flow channel or on a casing, when an engine has a low-pressure shaft failure event, a low-pressure rotor system at the rear end instantly starts to move backwards due to backward axial force applied to the low-pressure rotor system, a preset rotor and a preset stator instantly contact and collide grind, and a low-pressure turbine rotor limits the increase of the rotating speed under the friction action. Foreign rotor blade and stator blade or rotor rim terminal surface and the realization of cartridge receiver terminal surface bump to grind to mechanical type low pressure axle failure protection design adoption, low pressure axle failure protection effect can be realized to this type of design, but because blade or rim bump to grind the secondary destruction that causes not only increased other harm risks, increased the maintenance cost to blade or rim in later stage moreover.

SUMMERY OF THE UTILITY MODEL

One object of the present invention is to provide a low pressure shaft failure protection assembly that avoids dangerous events such as over-rotation due to low pressure shaft failure.

The above-mentioned low-pressure shaft failure protection subassembly sets up in low-pressure turbine part's back bearing assembly department, low-pressure turbine part includes rotor subassembly and stator subassembly, the low-pressure shaft failure protection subassembly includes: the first limiting assembly comprises a first limiting piece arranged on the rotor assembly and a third limiting piece arranged on the stator assembly; the second limiting assembly comprises a second limiting piece arranged on the rotor assembly and a fourth limiting piece arranged on the stator assembly; the first limiting part and the third limiting part are provided with a first initial gap along the axial direction of the engine, the second limiting part and the fourth limiting part are provided with a second initial gap therebetween, the first initial gap and the second initial gap are both smaller than the distance between any rotor assembly and a stator assembly in the low-pressure turbine component along the axial direction, and the rotor assembly can be limited relative to the stator assembly in the axial direction through the cooperation between the first limiting part and the third limiting part and the cooperation between the second limiting part and the fourth limiting part.

In one or more embodiments, the first limiting member and/or the second limiting member may be detachably connected to the rotor assembly, and the third limiting member and/or the fourth limiting member may be detachably connected to the stator assembly.

In one or more embodiments, along the axial direction, one side of the second limiting part, which is close to the first limiting part, is provided with a second limiting ring, and the other side is provided with a locking part, and the second limiting ring is detachably connected with the rotor assembly.

In one or more embodiments, along the axial direction, a first limiting ring is disposed on one side of the first limiting member close to the second limiting member, and the first limiting ring is detachably connected to the rotor assembly.

In one or more embodiments, the first retaining member has a first retaining surface, the third retaining member has a third retaining surface, and the first retaining surface conforms to the third retaining surface; the second limiting part is provided with a second limiting surface, the fourth limiting part is provided with a fourth limiting surface, and the second limiting surface is conformal with the fourth limiting surface.

In one or more embodiments, the first position-limiting surface, the second position-limiting surface, the third position-limiting surface, and the fourth position-limiting surface are all conical surfaces.

In one or more embodiments, the first restraint surface, the second restraint surface, the third restraint surface, and the fourth restraint surface each have an irregularly shaped surface.

In one or more embodiments, the third limiting member and/or the fourth limiting member are coated with a wear-resistant layer.

In one or more embodiments, the first limiting member and the second limiting member have the same structure, and the third limiting member and the fourth limiting member have the same structure.

The low-pressure shaft failure protection assembly with the mechanical limiting friction rotation reducing structure can quickly respond when an engine has a low-pressure shaft failure event, reduce the rotating speed of a low-pressure turbine rotor, and protect other parts of the engine, particularly a low-pressure turbine rotor stator part, from secondary damage.

It is another object of the present invention to provide a turbine engine that avoids hazardous events such as over-rev due to low pressure shaft failure.

The turbine engine includes the low pressure shaft failure protection assembly.

According to the turbine engine, the low-pressure shaft failure protection assembly is arranged, so that the turbine engine can quickly respond when the low-pressure shaft failure event occurs to the engine, the rotating speed of a low-pressure turbine rotor is reduced, and other parts of the engine, particularly the low-pressure turbine rotor and stator part, are protected from secondary damage.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of an aircraft engine low pressure turbine and aft bearing components according to an embodiment.

FIG. 2 is a schematic view of a low spool failure protection assembly in a normal state according to one embodiment.

FIG. 3 is a schematic view of a low pressure shaft failure protection assembly in a failure state according to one embodiment.

FIG. 4 is a schematic illustration of a low pressure shaft fail safe assembly in other states according to an embodiment.

FIG. 5 is a schematic view of a low pressure shaft failure protection assembly having a spacing assembly with an irregularly shaped interface, according to another embodiment.

FIG. 6 is a schematic view of a low spool fault protection assembly having a removable third stop according to yet another embodiment.

Description of symbol mark

1 low pressure turbine and rear bearing part

2 central axis of engine

3 low pressure turbine component

4 rear bearing part

5 Low-pressure shaft

6 rotor part

7 stator component

8 rear rotating shaft

9 rear bearing support

10 rear bearing assembly

11 first limit component

12 second limiting component

13. 13' first limiting part

14. 14 ', 14' third limiting part

15. 15' fourth limiting piece

16. 16' second limiting part

17. 17' first limit surface

18. 18' third limiting surface

19. 19' fourth limiting surface

20. 20' second limit surface

21 rear bearing inner ring

22 rear bearing slide block

23 second stop collar

24 locking piece

25 first limit ring

81 first connection part

91 second connection part

Angle alpha

d1 first initial gap

d 1' first gap

d2 second initial gap

d 2' second gap

X axial direction

Detailed Description

The present invention is further described in the following description with reference to specific embodiments and the accompanying drawings, wherein the details are set forth in order to provide a thorough understanding of the present invention, but it is apparent that the present invention can be embodied in many other forms different from those described herein, and it will be readily appreciated by those skilled in the art that the present invention can be implemented in many different forms without departing from the spirit and scope of the utility model. It is noted that these and other figures which follow are merely exemplary and not drawn to scale and should not be considered as limiting the scope of the utility model as it is actually claimed.

Fig. 1 shows a typical low-pressure turbine and rear bearing part 1 of a twin-rotor aircraft engine, mainly comprising a low-pressure turbine part 3, a low-pressure shaft 5 and a rear bearing assembly 10, wherein the low-pressure turbine part 3 comprises a rotor assembly comprising a rotor part 6 and a rear rotating shaft 8, and a stator assembly comprising a stator part 7, a rear bearing part 4 and a rear bearing support 9. The low-pressure shaft 5 is fixedly connected with a rear rotating shaft 8, and the rotor part 6 is connected with a rotor part in a rear bearing assembly 10 through the rear rotating shaft 8. The rear bearing part 4 is fixedly connected with the stator part 7, and the rear bearing part 4 is connected with the stator part in the rear bearing assembly 10 through the rear bearing support 9.

When the low-pressure shaft 5 of the engine takes place the failure incident, the rotational speed of the low-pressure turbine part 3 increases sharply, may cause serious damage to the engine, therefore, propose one kind to have mechanical spacing friction to fall the low-pressure shaft failure protection assembly that changes the structure, can reduce the structure through this spacing friction and avoid the low-pressure turbine rotor to take place to change excessively when taking place the low-pressure shaft 5 failure incident.

As shown in fig. 2, the rear rotating shaft 8 has a first connecting portion 81, the rear bearing support 9 has a second connecting portion 91, the first connecting portion 81 and the second connecting portion 91 are disposed opposite to each other, the second connecting portion 91 is supported on the first connecting portion 81 through the rear bearing assembly 10, the rear bearing assembly 10 includes a rear bearing inner ring 21 and a plurality of rear bearing sliders 22, and the plurality of rear bearing sliders 22 are movable in the circumferential direction of the rear bearing inner ring 21, so that the rotor portion 6 in the low pressure turbine and the rear bearing force component 1 can rotate relative to the stator portion 7.

The low-pressure shaft failure protection assembly is arranged at the rear bearing assembly 10 and comprises a first limiting assembly 11 and a second limiting assembly 12, and the first limiting assembly 11 and the second limiting assembly 12 are respectively arranged at two sides of a rear bearing inner ring 21 along the axial direction X of the engine.

The first limiting component 11 includes a first limiting member 13 and a third limiting member 14, the first limiting member 13 is disposed on the first connecting portion 81 and has a first limiting surface 17, the third limiting member 14 is disposed on the second connecting portion 91 and has a third limiting surface 18, and the movement of the rotor member 6 relative to the stator member 7 in the axial direction X can be limited by the cooperation of the first limiting surface 17 and the third limiting surface 18. In the embodiment shown in fig. 2, the engagement of the first stopper surface 17 with the third stopper surface 18 can stopper the rotor member 6 in the backward direction in the axial direction X with respect to the stator member 7.

The second limiting component 12 includes a second limiting member 16 and a fourth limiting member 15, the fourth limiting member 15 is disposed on the second connecting portion 91 and has a fourth limiting surface 19, the second limiting member 16 is disposed on the first connecting portion 81 and has a second limiting surface 20, and the movement of the rotor member 6 relative to the stator member 7 in the axial direction X can be limited by the cooperation of the fourth limiting surface 19 and the second limiting surface 20. In the embodiment shown in fig. 2, the engagement of the fourth stop surface 19 with the second stop surface 20 enables the rotor member 6 to be stopped relative to the stator member 7 in the forward direction of the axial direction X.

In one embodiment of the low-pressure shaft failure protection assembly, the fourth limiting member 15 and the second limiting member 16 in the second limiting assembly 12 are fixed on the second connecting portion 91 and the first connecting portion 81 respectively in a detachable connection manner, so as to facilitate processing, assembly, maintenance and replacement. When the low-pressure shaft failure protection assembly is installed, the rear bearing inner ring 21 and the plurality of rear bearing sliders 22 are installed, and then the fourth limiting member 15 and the second limiting member 16 are fixed to the second connection portion 91 and the first connection portion 81, respectively.

In the embodiment shown in fig. 2, the fourth limiting member 15 is fixed to the second connecting portion 91 by means of a bolt connection; the second limiting part 16 is disposed on the first connecting part 81 in a hole-shaft matching manner, and is fixedly connected to the second limiting ring 23 and the locking part 24, wherein the second limiting part 23 is disposed on one side of the second limiting part 16 close to the first limiting part 13 along the axial direction X, the locking part 24 is disposed on the other side of the second limiting part, and the second limiting ring 23 is detachably connected to the first connecting part 81. The axial distance between the fourth limiting member 15 and the second limiting member 16, i.e. the second initial gap d2 in fig. 2, can be adjusted and ensured by providing the second limiting ring 23 and the locking member 24.

In one embodiment, the first limiting member 13 is detachably connected to the first connecting portion 81, a first limiting ring 25 is disposed on a side of the first limiting member 13 close to the second limiting member 16 along the axial direction X, and the first limiting ring 25 is detachably connected to the rotor portion of the first connecting portion 81. The axial distance between the first limiting member 13 and the third limiting member 14, i.e. the first initial gap d1 in fig. 2, can be adjusted and ensured by providing the first limiting ring 25.

Under the normal operating condition of the engine, the distance between the first limiting member 13 and the third limiting member 14 in the axial direction X is a first initial gap d1, the distance between the second limiting member 16 and the fourth limiting member 15 in the axial direction X is a second initial gap d2, both the first initial gap d1 and the second initial gap d2 are smaller than the axial distance between the rotor assembly and the stator assembly at any one position in the low-pressure turbine component 3, so that in the event of a failure of the low-pressure shaft 5, the first limiting surface 17 of the first limiting member 13 will abut against the third limiting surface 18 of the third limiting member 14, and the distance between the fourth limiting member 15 and the second limiting member 16 in the axial direction X is d 2', as shown in fig. 3; or the fourth limiting surface 19 of the fourth limiting member 15 abuts against the second limiting surface 20 of the second limiting member 16, and the distance between the first limiting member 13 and the third limiting member 14 in the axial direction X is d 1', as shown in fig. 4, but the rotor component 6 and the stator component 7 do not contact with each other, so as to ensure that the low-pressure turbine rotor-stator component is protected from secondary damage when the low-pressure shaft 5 fails. Meanwhile, the first initial clearance d1 and the second initial clearance d2 are arranged to ensure that the rotor and stator interference of the engine does not occur under the normal working condition.

The low pressure shaft fail safe assembly is further described in conjunction with fig. 3 and 4:

when the low-pressure shaft 5 of the engine fails, the rotor part 6 is acted by the axial force of the gas, and drives the rear rotating shaft 8 and the rotor assembly in the rear bearing assembly 10 to move backwards. The failure state is as shown in fig. 3, the first limit surface 17 and the third limit surface 18 contact after the low-pressure shaft 5 fails, friction is generated on the contact surface of the rotor assembly and the low-pressure shaft due to backward axial force applied to the rotor assembly, and the rotating speed of the low-pressure turbine rotor assembly 3 is reduced under the action of the friction, so that further damage caused by an over-rotation event is prevented.

When the low pressure shaft 5 of the engine fails, the rotor member 6, the rear rotating shaft 8 and the rotor assembly of the rear bearing assembly 10 may otherwise move forward in the axial direction X. As shown in fig. 4, the fourth stopper surface 19 and the second stopper surface 20 contact with each other in this state, and a friction force is generated on the contact surface between the fourth stopper surface and the second stopper surface, and the low pressure turbine rotor assembly 3 further reduces the rotation speed by the friction force.

As shown in fig. 3, the first limiting member 13 has a first limiting surface 17, the third limiting member 14 has a third limiting surface 18, and the first limiting surface 17 and the third limiting surface 18 are conformal; the second limiting member 16 has a second limiting surface 20, the fourth limiting member 15 has a fourth limiting surface 19, and the second limiting surface 20 and the fourth limiting surface 19 are conformal.

In the embodiment shown in fig. 3, taking the first limiting member 11 as an example, the first limiting surface 17 and the third limiting surface 18 are both conical surfaces, contact surfaces of the first limiting surface 17 and the third limiting surface 18 can be completely attached to each other, an included angle α is formed between the contact surfaces and the central axis 2 of the engine, and the supporting force of the first limiting member 13 in the axial direction X and the radial direction can be changed by changing the size of the included angle α. For example, when the included angle α is increased, when the first limiting surface 17 contacts the third limiting surface 18, the first limiting member 13 will obtain a larger axial X supporting force, so as to generate a larger friction force, and the rotation speed of the low-pressure turbine rotor assembly 3 can be reduced more quickly. Similarly, the effect of rapidly reducing the rotation speed can be obtained in other states after failure by changing the included angle between the contact surface of the rotor and stator limiting member in the second limiting assembly 12 and the central axis 2 of the engine.

The shape of the contact surface of the rotor/stator limiting member in the first limiting member 11 and the second limiting member 12 is not limited to this, and may also be a plane, that is, the contact surface of the first limiting surface 17 and the third limiting surface 18 or the contact surface of the fourth limiting surface 19 and the second limiting surface 20 is a vertical surface perpendicular to the first connecting portion 81, or other surface with an irregular shape. In another embodiment, the protection component with the irregular contact surface is shown in fig. 5, the first limiting component 11 includes a first limiting component 13 'and a third limiting component 14', the first limiting component 13 'has a first limiting surface 17' with an irregular surface, and the third limiting component 14 'has a third limiting surface 18' with an irregular surface; the second position-limiting component 12 includes a fourth position-limiting component 15 'and a second position-limiting component 16', the fourth position-limiting component 15 'has a fourth position-limiting surface 19' with an irregular surface, and the second position-limiting component 16 'has a second position-limiting surface 20' with an irregular surface. In this embodiment, by providing the rotor/stator limiting member as a limiting surface having a cross section similar to a step shape, the contact area between the limiting surfaces of the rotor/stator limiting member can be increased without increasing the distance between the first connecting portion 81 and the second connecting portion 91, providing a better rotation reduction effect.

In one embodiment, the surfaces of the stator limiting parts in the first limiting assembly 11 and the second limiting assembly 12 are coated with wear-resistant layers, that is, the third limiting surface 18 and the fourth limiting surface 19 are coated with wear-resistant layers, so that the stator limiting parts are protected, and only the wear-resistant layers need to be replaced when the low-pressure shaft failure protection structure is replaced, so that the maintenance cost of the low-pressure shaft failure protection structure can be reduced. In addition, the friction force between the rotor and stator limiting parts can be increased by changing the material of the wear-resistant layer, so that the effect of quickly rotating is achieved.

As shown in fig. 2, in the first limiting member 11, the first limiting member 13 and the first connecting portion 81 are integrally formed. In another embodiment, the first limiting member 13 can also be axially engaged through the hole and fixedly connected to the first connecting portion 81 by an axial locking structure, and the axial distance between the first limiting member 13 and the third limiting member 14, i.e. the first initial gap d1, can be adjusted and ensured by providing the axial locking structure.

In the embodiment shown in fig. 2, the third stopper 14 is integrally formed with the second connecting portion 91. In another embodiment shown in fig. 6, the third limiting member 14 ″ can be detachably fixed to the second connecting portion 91 by bolts or the like. Through with the spacing part of the rotor stator in the first spacing subassembly 11 with low pressure turbine part 3 fixed connection in a detachable mode, be convenient for processing, maintenance and change.

In one embodiment, the first limiting member 13 and the second limiting member 16 are both detachably connected to the first connecting portion 81, the third limiting member 14 and the fourth limiting member 15 are both detachably connected to the second connecting portion 91, the first limiting member 13 and the second limiting member 16 have the same structure, and the third limiting member 14 and the fourth limiting member 15 have the same structure, so as to facilitate replacement and maintenance of the low-voltage shaft failure protection structure.

By adopting the low-pressure shaft failure protection assembly with the mechanical limiting friction rotation reducing structure, when an engine has a low-pressure shaft failure event, the low-pressure shaft failure protection assembly can quickly respond, reduce the rotating speed of a low-pressure turbine rotor and protect other parts of the engine, particularly a low-pressure turbine rotor stator part, from secondary damage.

Although the present invention has been disclosed in terms of the preferred embodiment, it is not intended to limit the utility model, and variations and modifications may be made by one skilled in the art without departing from the spirit and scope of the utility model. Therefore, any modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope defined by the claims of the present invention, unless the technical essence of the present invention departs from the content of the present invention.

Claims (10)

1. A low pressure shaft failure protection assembly disposed at a rear bearing assembly of a low pressure turbine component, the low pressure turbine component including a rotor assembly and a stator assembly, the low pressure shaft failure protection assembly comprising:

the first limiting assembly comprises a first limiting piece arranged on the rotor assembly and a third limiting piece arranged on the stator assembly; and

the second limiting assembly comprises a second limiting piece arranged on the rotor assembly and a fourth limiting piece arranged on the stator assembly;

the first limiting part and the third limiting part are provided with a first initial gap along the axial direction of an engine, the second limiting part and the fourth limiting part are provided with a second initial gap therebetween, the first initial gap and the second initial gap are both smaller than the axial distance between the rotor assembly and the stator assembly at any position in the low-pressure turbine part, and the rotor assembly can be limited relative to the stator assembly in the axial direction through the cooperation between the first limiting part and the third limiting part and the cooperation between the second limiting part and the fourth limiting part.

2. The low spool failure protection assembly of claim 1, wherein the first retaining member and/or the second retaining member is removably coupled to the rotor assembly and the third retaining member and/or the fourth retaining member is removably coupled to the stator assembly.

3. The low spool failure protection assembly of claim 2, wherein a second retaining ring is disposed on one side of the second retaining member adjacent to the first retaining member and a retaining member is disposed on the other side of the second retaining member in the axial direction, the second retaining ring being detachably connected to the rotor assembly.

4. The low spool failure protection assembly of claim 2, wherein a first retaining ring is disposed on a side of the first retaining member adjacent to the second retaining member in the axial direction, the first retaining ring being removably coupled to the rotor assembly.

5. The low spool failure protection assembly of claim 1, wherein the first retaining member has a first retaining surface and the third retaining member has a third retaining surface, the first retaining surface conforming to the third retaining surface;

the second limiting part is provided with a second limiting surface, the fourth limiting part is provided with a fourth limiting surface, and the second limiting surface is conformal with the fourth limiting surface.

6. The low spool failure protection assembly of claim 5, wherein the first stop surface, the second stop surface, the third stop surface, and the fourth stop surface are tapered surfaces.

7. The low spool failure protection assembly of claim 5, wherein the first stop surface, the second stop surface, the third stop surface, and the fourth stop surface each have an irregularly shaped surface.

8. The low spool failure protection assembly of claim 1, wherein the third retaining member and/or the fourth retaining member is coated with a wear layer.

9. The low spool failure protection assembly of claim 2, wherein the first retaining member and the second retaining member have the same structure, and the third retaining member and the fourth retaining member have the same structure.

10. A turbine engine comprising the low pressure shaft failure protection assembly of any of claims 1 to 9.

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