CN116658455A - Local air inlet impact turbine rotor and assembly method - Google Patents

Abstract

The invention discloses a partial intake impingement type turbine rotor and an assembly method thereof, which relate to the technical field of rocket engines and solve the problems of relatively large cyclic stress amplitude at the root of the blade, high-frequency fatigue damage that is likely to occur, and relatively short service life. The partial intake impingement turbine rotor includes a rotor shaft, a plurality of blades and guard strips, the plurality of blades are evenly arranged on the periphery of the rotor shaft, and the root of each blade is fixedly connected to the rotor shaft, and each blade There are grooves on the top of each blade; the guard belt is a circular structure, the guard belt is clamped in the groove of each blade, and the guard belt is fixedly connected with each blade. The method for assembling the partial air impingement turbine rotor is used for assembling the above partial air impingement turbine rotor. The local intake impingement turbine rotor and assembly method provided by the invention are used to reduce the cyclic stress amplitude at the root of the turbine blade, thereby improving the fatigue life of the turbine rotor.

Description

Partial intake impingement turbine rotor and assembly method thereof

technical field

The invention relates to the technical field of rocket engines, in particular to a partial intake impingement turbine rotor and an assembly method.

Background technique

In the turbopump design of an open-cycle liquid rocket engine, the turbine generally adopts a partial intake impingement turbine rotor, and the rotor generally includes a rotor shaft and a plurality of blades, and the plurality of blades are fixedly arranged on the periphery of the rotor shaft.

During work, the turbine rotor needs to rotate at high speed under the blowing of the high-temperature working medium. Because of the local air intake structure, each blade of the rotor will be blown by the turbine nozzle once every time the turbine rotates, and the load on the turbine rotor blades is obvious. Therefore, the fatigue failure of the turbine rotor blades of the open cycle liquid rocket engine is generally manifested as high frequency fatigue damage.

The blade is a cantilever force-bearing structure with the root fixed on the rotor shaft and the top suspended in the air. When the rotor blades are blown by the turbine nozzle in turn, only the rotor shaft provides support for the blade root, and stress concentration is generated at the blade root, making the circulation of the blade root The stress range is large, it is easy to produce high-frequency fatigue damage, and the service life is relatively short.

Contents of the invention

The object of the present invention is to provide a partial intake impingement type turbine rotor and an assembly method, which are used to reduce the cyclic stress amplitude at the root of the turbine blade, thereby improving the fatigue life of the turbine rotor.

In order to achieve the above object, the present invention provides a partial intake impingement turbine rotor, comprising:

rotor shaft;

A plurality of blades, the plurality of blades are evenly arranged on the peripheral side of the rotor shaft, and the root of each blade is fixedly connected with the rotor shaft, and the top of each blade is provided with a groove;

The guard band, the guard band is a circular structure, the guard band is clamped in the groove of each blade, and each blade of the guard band is fixedly connected.

Compared with the prior art, the present invention provides a partial intake impingement turbine rotor including a guard band, which is clamped in the groove of each blade and fixedly connected with each blade, and the high-temperature working medium is injected into the turbine nozzle. Blowing to some blades that are fixedly connected to the rotor shaft, because the guard band is fixedly connected to the top of the blade, when the blade is stressed, the guard band will provide the top of the blade with a support force opposite to the direction of blade movement, thereby reducing the blade root. stress concentration, thereby reducing the cyclic stress amplitude at the blade root. Based on this, the invention provides a partial intake impingement turbine rotor including a guard band, which will provide the top of the blade with a supporting force opposite to the direction of blade movement, the displacement generated by the top of the blade will be reduced, and the stress on the root of the blade will be reduced. Concentrated reduction, thereby reducing the cyclic stress amplitude at the root of the blade, and improving the service life of the turbine rotor; in addition, the guard band is clamped in the groove of each blade, and the width of the guard band is smaller than the width of the groove, that is, the guard band The width of the blade is smaller than the width of each blade, therefore, the outer profile width of the original turbine rotor is not affected after the guard belt is installed.

Optionally, in the above-mentioned partial intake impingement turbine rotor, the guard band is welded to each blade.

Optionally, in the above-mentioned partial intake impingement turbine rotor, the width of the groove is 70%-80% of the width of the blade.

Optionally, in the above-mentioned partial intake impingement turbine rotor, the depth of the groove is equal to the thickness of the guard band.

Optionally, in the above-mentioned partial intake impingement turbine rotor, the thickness of the guard band is 1mm-1.5mm.

Optionally, in the above-mentioned partial intake impingement turbine rotor, the guard band is made of GH3128 nickel-based alloy material or GH4169 nickel-based alloy material.

The present invention also provides a method for assembling the partial intake impingement turbine rotor, which is used for assembling the above partial intake impingement turbine rotor, including:

grooves are formed at the top of each blade;

The blades are fixedly connected to the rotor shaft in turn;

The strip is rounded, and the strip is clamped in the groove of each blade in turn, and the strip is welded to the top of each blade by electron beam welding to form the first weld, and the butt joints at both ends of the strip are The interface is welded to form a second weld seam, forming a guard band.

Through the assembling method of the local intake impingement turbine rotor provided by the present invention, the guard band can be fixedly arranged on the top of the blade, and the guard band provides the top of the blade with a support force opposite to the direction of blade movement, so that the blade The displacement generated at the top is reduced, and the stress concentration at the blade root is reduced, thereby reducing the cyclic stress amplitude at the blade root and improving the service life of the turbine rotor.

Optionally, in the above-mentioned method for assembling the partial intake impingement turbine rotor, after opening a groove on the top of each blade, the strip is rounded, and the strip is snapped into the groove of each blade in turn, Electron beam welding is used to weld the strip to the top of each blade to form a first weld, and the butt joints at both ends of the strip are welded to form a second weld. The assembly method of the type turbine rotor also includes:

According to the thermal expansion coefficient of the blade material, select the strip material;

The strip is processed according to the distance from the bottom of the groove to the axis of rotation of the rotor shaft and the width of the groove so that the width of the strip is smaller than the groove and the length is greater than 2π times the vertical distance from the bottom of the groove to the axis of rotation of the rotor shaft.

Optionally, in the above-mentioned method for assembling the partial intake impingement turbine rotor, the strip is rounded, and the strip is snapped into the groove of each blade in turn, and each blade is welded by electron beam welding. After welding the top of the strip, and welding the two ends of the strip to form a guard strip, the above-mentioned assembly method of the partial intake impingement turbine rotor also includes:

Ultrasonic inspection of the first weld between the blade and the guard belt;

Carry out X-ray inspection of the second weld of the butt joint of the guard belt.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

Fig. 1 is a structural schematic diagram of a partial intake impingement turbine rotor provided by an embodiment of the present invention;

Fig. 2 is a partial schematic diagram of blades, guard bands and connections of a partial intake impingement turbine rotor provided by an embodiment of the present invention;

Fig. 3 is a cross-sectional view of the connection between the blade and the guard belt of a partial intake impingement turbine rotor provided by an embodiment of the present invention;

Fig. 4 is a flow chart of an assembly method of a partial intake impingement turbine rotor provided by an embodiment of the present invention;

Fig. 5 is a flow chart of another assembly method of a partial air impingement turbine rotor provided by an embodiment of the present invention.

Reference signs:

1-rotor shaft; 2-blade; 3-guard belt; 4-first weld; 5-second weld.

Detailed ways

In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

It should be noted that when an element is referred to as being “fixed” or “disposed on” another element, it may be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. "Several" means one or more than one, unless otherwise clearly and specifically defined.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right" etc. are based on those shown in the accompanying drawings. Orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connection, or integral connection; can be mechanical connection or electrical connection; can be direct connection or indirect connection through an intermediary, and can be the internal communication of two elements or the interaction relationship between two elements. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the turbopump design of an open-cycle liquid rocket engine, the turbine generally adopts a partial intake impingement turbine rotor, and the rotor generally includes a rotor shaft and a plurality of blades, and the plurality of blades are fixedly arranged on the periphery of the rotor shaft. During work, the turbine rotor needs to rotate at high speed under the blowing of the high-temperature working medium. Because of the local air intake structure, each blade of the rotor will be blown by the turbine nozzle once every time the turbine rotates, and the load on the turbine rotor blades is obvious. Therefore, the fatigue failure of the turbine rotor blades of the open cycle liquid rocket engine is generally manifested as high frequency fatigue damage. The blade is a cantilever force-bearing structure with the root fixed on the rotor shaft and the top suspended in the air. When the rotor blades are blown by the turbine nozzle in turn, only the rotor shaft provides support for the blade root, and stress concentration is generated at the blade root, making the circulation of the blade root The stress range is large, it is easy to produce high-frequency fatigue damage, and the service life is relatively short.

In order to solve the above-mentioned problems, please refer to Fig. 1 and Fig. 2, the embodiment of the present invention provides a kind of partial intake impingement type turbine rotor, including the rotor shaft 1, a plurality of blades 2 and guard bands 3, and the plurality of blades 2 are evenly arranged on The peripheral side of the rotor shaft 1, and the root of each blade 2 is fixedly connected with the rotor shaft 1, and a groove is provided on the top of each blade 2; In the groove of each blade 2 , the guard band 3 is fixedly connected with each blade 2 .

In the specific working process, the turbine nozzle blows the high-temperature working medium onto several blades 2 fixedly connected to the rotor shaft 1. After the blades 2 are stressed, all the blades 2 and the rotor shaft 1 rotate together. After the position of the blades 2 changes, The turbine nozzle blows the high-temperature working medium to the blade 2 corresponding to the position of the nozzle, and in this way, each blade 2 is cyclically stressed to control the rotation of the rotor.

According to the structure and specific working process of a partial intake impingement turbine rotor provided by the embodiment of the present invention, it can be seen that the partial intake impingement turbine rotor provided by the embodiment of the present invention includes a guard band 3, and the guard band 3 is clamped on the In the groove of each blade 2, and fixedly connected with each blade 2, the high-temperature working medium is blown to several blades 2 fixedly connected with the rotor shaft 1 at the turbine nozzle, because the guard belt 3 is fixed to the top of the blade 2 Connection, when the blade 2 is stressed, the guard belt 3 will provide the top of the blade 2 with a supporting force opposite to the direction of motion of the blade 2, thereby reducing the stress concentration at the root of the blade 2, thereby reducing the cyclic stress amplitude at the root of the blade 2. Compared with the prior art, the partial intake impingement turbine rotor provided by the embodiment of the present invention includes a guard band 3, which will provide the top of the blade 2 with a support force opposite to the direction of motion of the blade 2, and the top of the blade 2 will generate The displacement of the blade 2 is reduced, the stress concentration at the root of the blade 2 is reduced, and the cyclic stress amplitude at the root of the blade 2 is reduced, and the service life of the turbine rotor is improved; in addition, the guard belt 3 is clamped in the groove of each blade 2, The width of the guard band 3 is smaller than the width of the groove, that is, the width of the guard band 3 is smaller than the width of each blade 2. Therefore, the outer profile width of the original turbine rotor is not affected after the guard band 3 is installed.

Specifically, in the aforementioned partial intake impingement turbine rotor, the guard band 3 is welded to each blade 2 . The connection mode of welding is relatively stable, which ensures the connection strength between the guard belt 3 and the blade 2 , and each blade 2 is fixedly connected with the guard belt 3 , and the guard belt 3 can provide greater supporting force for each blade 2 . .

Specifically, please refer to 3, in the above-mentioned partial intake impingement turbine rotor, the guard band 3 is welded to the two side walls and the bottom three sides of the groove of each blade 2 . Through welding on three sides, the connection strength between the guard belt 3 and the blade 2 is further ensured.

Specifically, in the above-mentioned local intake impingement turbine rotor, the width of the groove is 70% to 80% of the width of the blade 2; for example, the width of the groove is 70%, 72%, 75%, 78%, 80%, etc.

Specifically, in the above-mentioned partial intake impingement turbine rotor, the depth of the groove is equal to the thickness of the guard band 3 . In this way, the outer circumference of the guard band 3 is flush with the outer circumference of the blade 2, and the maximum diameter of the outer profile of the original turbine rotor will not be affected after the guard band 3 is installed.

Specifically, in the aforementioned partial air impingement turbine rotor, the thickness of the guard band 3 is 1 mm to 1.5 mm; for example, the thickness of the guard band 3 is 1 mm, 1.2 mm, 1.4 mm, 1.5 mm and so on. Under the condition of ensuring the structural strength of the guard band 3, the thickness of the guard band 3 is reduced, thereby reducing the mass of the guard band 3, which facilitates the rotation of the rotor and facilitates the processing of the guard band 3.

In some embodiments, in the aforementioned partial intake impingement turbine rotor, the guard strip 3 is made of GH3128 nickel-based alloy material or GH4169 nickel-based alloy material. GH3128 nickel-based alloy material and GH4169 nickel-based alloy material have high plasticity, high durable creep strength, good oxidation resistance and good stamping and welding performance, ensuring the performance of the guard belt 3 and meeting the work of the turbine rotor Ambient temperature and load requirements, in addition, the material of the turbine blade 2 is mainly nickel-based alloy, the thermal expansion coefficient of the GH3128 nickel-based alloy material and GH4169 nickel-based alloy material is equivalent to that of the blade 2 material, to prevent the thermal expansion of the blade 2 and the guard belt 3 The different coefficients lead to the fracture of the weld between the blade 2 and the guard 3.

Please refer to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the present invention also provides a method for assembling the partial intake impingement turbine rotor, which is used to assemble the above partial intake impingement turbine rotor, including:

S101, opening a groove on the top of each blade 2; specifically, opening grooves of the same size on the top of each blade 2 by a lathe;

S102, fixedly connecting the blades 2 to the rotor shaft 1 in turn;

S103, round the strip, and clamp the strip in the groove of each blade 2 in turn, and use electron beam welding to weld the strip and the top of each blade 2 to form a first weld 4, and The butt joints at both ends of the strip are welded to form a second weld 5 , forming the guard strip 3 .

Through the assembly method of a local intake impingement turbine rotor provided by the embodiment of the present invention, the guard band 3 can be fixedly arranged on the top of the blade 2, and the guard band 3 provides the top of the blade 2 with a movement direction opposite to that of the blade 2. The supporting force reduces the displacement generated at the top of the blade 2 and reduces the stress concentration at the root of the blade 2, thereby reducing the cyclic stress amplitude at the root of the blade 2 and improving the service life of the turbine rotor.

Please refer to Fig. 1, Fig. 2, Fig. 3 and Fig. 5, the present invention also provides another method for assembling the partial intake impingement turbine rotor, which is used to assemble the above partial intake impingement turbine rotor, including:

S201. Opening a groove on the top of each blade 2; specifically, opening grooves of the same size on the top of each blade 2 by a lathe.

S202, fixedly connecting the blades 2 to the rotor shaft 1 in turn;

S203. Select the strip material according to the coefficient of thermal expansion of the material of the blade 2; for example, when the material of the turbine blade 2 is a nickel-based alloy, the material of the guard strip 3 is a GH3128 nickel-based alloy material or a GH4169 nickel-based alloy material;

S204. Process the strip according to the distance from the bottom of the groove to the rotation axis of the rotor shaft 1 and the width of the groove, so that the width of the strip is smaller than the groove and the length is greater than the vertical distance from the bottom of the groove to the rotation axis of the rotor shaft 1 2π times of;

Based on this, it can be ensured that the strip can be clamped in the groove, and that the strip can go around the top of each blade 2 for a circle.

S205, round the strip, and clamp the strip in the groove of each blade 2 in turn, and use electron beam welding to weld the strip to the top of each blade 2 to form a first weld 4, and The butt joints at both ends of the strip are welded to form a second weld 5, forming a guard strip 3;

Specifically, after the strip wraps around the top of each blade 2, if there is any excess strip, first cut off the excess strip, and then weld the butt joints at both ends of the strip to form a second weld 5, forming Guard belt 3.

S206, performing an ultrasonic inspection on the first weld 4 between the blade 2 and the belt 3;

Specifically, ultrasonically check whether the weld fusion width between the guard zone of the first weld 4 and the top of the blade is greater than a preset width, and the preset width is the minimum fusion width of the weld to ensure the connection strength between the blade 2 and the guard zone 3 .

S207 , performing an X-ray inspection on the second weld 5 of the butt joint of the guard belt 3 .

Specifically, whether the internal quality of the second welding seam 5 of the butt joint of the guard belt 3 meets the standard requirements is checked by X-ray.

In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in an appropriate manner.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (9)

1. A partial intake impingement turbine rotor, comprising:

a rotor shaft;

the blades are uniformly arranged on the periphery of the rotor shaft, the root of each blade is fixedly connected with the rotor shaft, and the top of each blade is provided with a groove;

the guard belt is of a circular ring structure, wei Dai is clamped in the groove of each blade, and the guard belt is fixedly connected with each blade.

2. The partial-induction impingement turbine rotor of claim 1, wherein said guard band is welded to each of said blades.

3. The partial charge impingement turbine rotor of claim 1, wherein the width of the groove is 70% -80% of the width of the blade.

4. The partial-induction impingement turbine rotor of claim 1, wherein a groove depth of the groove is equal to a thickness of the guard band.

5. The partial charge impingement turbine rotor of claim 4, wherein the thickness of the guard band is 1mm to 1.5mm.

6. The partial charge impingement turbine rotor of claim 1, wherein the material of the guard band is a GH3128 nickel-based alloy material or a GH4169 nickel-based alloy material.

7. A method of assembling a partial charge impingement turbine rotor according to any of claims 1-6, comprising:

a groove is formed in the top of each blade;

fixedly connecting the blades with a rotor shaft in sequence;

and rounding the strip, sequentially clamping the strip in the grooves of each blade, welding the strip and the top of each blade by adopting electron beam welding to form a first welding seam, and welding butt joint interfaces at two ends of the strip to form a second welding seam to form the guard belt.

8. The method of assembling a partial intake impulse turbine rotor as claimed in claim 7, wherein after the grooves are formed in the top of each blade, the rolling the strip material, clamping the strip material in the grooves of each blade in turn, welding the strip material and the top of each blade by electron beam welding to form a first weld joint, and welding butt joints at two ends of the strip material to form a second weld joint, and before forming the guard band, the method of assembling a partial intake impulse turbine rotor further comprises:

selecting a strip according to the thermal expansion coefficient of the blade material;

and machining the strip according to the distance between the bottom of the groove and the rotation axis of the rotor shaft and the width of the groove, so that the width of the strip is smaller than the groove, and the length is larger than 2 pi times of the perpendicular distance between the bottom of the groove and the rotation axis of the rotor shaft.

9. The method of assembling a partial suction impulse turbine rotor as claimed in claim 7, wherein after rounding the strip material and clamping the strip material in the grooves of each of the blades in turn, welding the strip material to the top of each of the blades using electron beam welding, and fusion welding the two ends of the strip material to form a guard band, the method of assembling a partial suction impulse turbine rotor further comprises:

performing ultrasonic inspection on a first welding line of the blade and the sanitary belt;

and performing X-ray inspection on a second welding line of the butt joint interface of the sanitary belt.