Clearance variation measuring device and method, engine test piece, and cold clearance design method

Abstract

A gap variation measuring device for measuring the gap variation of a gilled structure under a hot state, the gilled structure comprising a gilled disc and a stator, the gilled disc and the stator forming a sealing structure, the gilled gap being the distance between the gilled disc and the stator, the gap variation measuring device comprising a protrusion arranged on the stator, the protrusion being made of an abradable material, so that when the gilled disc collides with the protrusion under a hot state, the gills of the gilled disc can cut into the protrusion, and the gilled gap variation can be obtained by measuring the radial cutting depth of the gills on the protrusion. An engine test piece, a gap variation measuring method and a gilled structure cold-state gap design method are also provided.

Description

Technical Field

[0001] This invention relates to the design of aero-engine air systems, specifically to a device and method for measuring clearance variation, an engine test piece, and a cold clearance design method. Background Technology

[0002] The air system of civil aviation turbofan engines typically draws air from the compressor, which flows through pipelines or internal structures such as discs, shafts, holes, and grates to the turbine end. After cooling and sealing the turbine and its bearings, the air is discharged into the mains or into the bearing cavity. The grates are an important sealing structure, generally composed of multiple rotating tooth-like structures and stationary honeycomb structures. The grates reduce airflow and pressure, thus achieving a seal.

[0003] In current mainstream aero-engine designs, the tooth structure and clearance need to be rationally designed to ensure normal engine operation throughout the entire flight cycle. The tooth clearance changes under different engine operating conditions. During actual operation, the tooth clearance should be as small as possible, and the risk of rubbing should be controlled as much as possible. Deep rubbing can lead to vibration risks, which in severe cases threaten engine safety. Determining a reasonable cold-state tooth clearance is a crucial task in engine design. Summary of the Invention

[0004] One object of the present invention is to provide a gap change measuring device for measuring the gap change of a tooth structure under hot conditions.

[0005] The aforementioned gap change measuring device is used to measure the gap change of a toothed structure under hot conditions. The toothed structure includes a toothed disc and a stationary component. The toothed disc and the stationary component form a sealed structure. The tooth gap is the distance between the toothed disc and the stationary component. The gap change measuring device includes a protrusion disposed on the stationary component. The protrusion is made of a wearable material, so that when the toothed disc and the protrusion rub against each other under hot conditions, the teeth of the toothed disc can cut into the protrusion. The gap change is obtained by measuring the radial cutting depth of the teeth into the protrusion.

[0006] In one or more embodiments, the toothed disc is a rotating body, and a plurality of the protrusions are arranged on the stator along the rotation direction of the toothed disc.

[0007] In one or more embodiments, the stationary element and the protrusion have a honeycomb structure.

[0008] In one or more embodiments, the stationary component and the protrusion are integral.

[0009] The protrusion in the aforementioned clearance change measuring device can record wear traces. After the engine test piece completes at least one full cycle of operation, the tooth structure is disassembled, and the maximum radial penetration depth of the tooth disc on the protrusion can be measured. This maximum penetration depth is the maximum tooth clearance change during engine operation, providing a basis for designing the optimal cold clearance value between the tooth disc and the stator, ensuring that the engine will not experience rubbing due to excessively small tooth clearance under different operating conditions, thus affecting engine safety performance. At the same time, since the contact area between the protrusion and the tooth disc is relatively small, the rubbing vibration during the measurement process is small, thus having a smaller impact on the clearance change measurement value, resulting in more accurate measurement results.

[0010] Another object of the present invention is to provide an engine test piece for measuring the change in the gap between the grates in a hot state.

[0011] The aforementioned engine test piece includes a toothed disc and a stator, wherein the toothed disc and the stator form a seal, and also includes the aforementioned clearance change measuring device, which measures the change in tooth clearance between the toothed disc and the stator under hot conditions.

[0012] The gap change measuring device used in the above-mentioned engine test piece can measure the maximum gap change of the tooth structure under hot conditions, providing a basis for designing the optimal cold-state gap value between the tooth disc and the stator, ensuring that the engine will not rub against each other due to excessively small tooth gap under different operating conditions, thus affecting the engine's safety performance, and the measurement results are more accurate.

[0013] Another object of the present invention is to provide a method for measuring the change in gap, for measuring the change in gap between grates under hot conditions.

[0014] The above-mentioned method for measuring the gap change is used to measure the gap change of a toothed structure under hot conditions. The method includes the following steps: providing an engine test piece, including a toothed disc and a stator; providing a protrusion on the stator, the protrusion being made of a wear-resistant material so that the toothed disc can cut into the protrusion; assembling the toothed disc and the stator to form a seal; starting the engine test piece and completing at least one full cycle of operation, causing the toothed disc and the protrusion to rub against each other under different operating conditions of the engine test piece; disassembling the toothed disc and the stator, measuring and recording the radial cutting depth of the toothed disc into the protrusion, which is the gap change of the toothed structure under hot conditions.

[0015] In one or more embodiments, the cutting depth is measured by means of a micrometer or vernier caliper.

[0016] The aforementioned method for measuring clearance variation records wear marks through the protrusion. After the engine test, the protrusion is measured to obtain the maximum radial penetration depth of the toothed disc on the protrusion. This maximum penetration depth is the maximum tooth clearance variation during engine operation, providing a basis for designing the optimal cold clearance value between the toothed disc and the stator. This ensures that the engine will not experience wear due to excessively small tooth clearance under different operating conditions, thus affecting engine safety performance. At the same time, the measurement results are more accurate.

[0017] Another objective of this invention is to provide a cold-state gap design method for a toothed structure, ensuring that the engine will not experience rubbing due to excessively small tooth gaps under different operating conditions, thus affecting engine safety performance, while also providing a better sealing effect.

[0018] The above-mentioned cold-state clearance design method for the sieve structure uses the above-mentioned clearance change measurement method to measure the clearance change of the sieve structure under hot conditions. The cold-state clearance determination method for the sieve structure further includes the following steps: before starting the engine test piece, determine the radial distance between the tooth tip of the sieve disc and the protrusion, and record it as the first clearance value; design the cold-state clearance between the sieve disc and the stator based on the measured first clearance value and the clearance change.

[0019] The above-mentioned cold-state clearance design method for the toothed structure measures the first clearance value and the change in toothed clearance. Subtracting the first clearance value from the maximum change in toothed clearance gives the optimal cold-state clearance value between the toothed disc and the stator. When designing the toothed structure, the toothed clearance is designed to be greater than this optimal cold-state clearance value. This ensures that the engine will not experience rubbing due to insufficient toothed clearance under different operating conditions, which would affect the engine's safety performance, nor will it affect the sealing effect due to excessive clearance, thus guaranteeing the overall performance of the engine. Attached Figure Description

[0020] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0021] Figure 1 This is a cross-sectional view of a toothed structure according to one embodiment.

[0022] Figure 2 This is a side view of a comb structure according to one embodiment.

[0023] Figure 3 This is a side view of a gap change measuring device according to an embodiment.

[0024] Symbol marking explanation

[0025] 1 static component

[0026] 2 Grate Discs

[0027] 3 protrusions

[0028] 4. Rotation direction

[0029] 11 Inner circumferential surface

[0030] 21 tooth tips

[0031] 22 teeth Detailed Implementation

[0032] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description to provide a full understanding of the invention. However, the invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual applications without departing from the spirit of the invention. Therefore, the scope of protection of the invention should not be limited by the content of these specific embodiments. It should be noted that these and subsequent accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the actual scope of protection claimed by the invention.

[0033] In the description of this invention, the terms "front," "rear," "left," "right," "up," "down," "horizontal," and "vertical" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0034] Figure 1 and Figure 2 A toothed sealing structure is shown. Due to factors such as machining tolerance, assembly error and engine vibration, a certain gap needs to be left between the toothed disc 2 and the stator 1 when designing the sealing structure. This gap is the cold gap of the toothed structure.

[0035] During actual engine operation, the gap between the toothed grates changes under different operating conditions. Too small a gap may cause component rubbing, leading to vibration risks and impacting engine safety; too large a gap will affect the sealing effect and reduce overall engine performance. Therefore, in engine testing, it is necessary to determine the change in gap of the toothed structure under engine hot conditions, and then determine the optimal cold-state gap value based on this change.

[0036] On the one hand, according to some embodiments of this application, a gap change measuring device is provided, such as... Figure 3The gap change measuring device shown can be used to measure the gap change of a toothed structure under hot conditions. The toothed structure includes a toothed disc 2 and a stator 1. The toothed disc 2 is mounted on the rotor component of the engine test piece, and the stator 1 is mounted on the stator component. The toothed disc 2 and the stator 1 form a seal. The gap change measuring device includes a protrusion 3 on the stator 1. The protrusion 3 is made of a wearable material, so that when the toothed disc 2 and the protrusion 3 rub against each other under hot conditions, the teeth 22 of the toothed disc 2 can cut into the protrusion 3. The gap change is obtained by measuring the radial cutting depth of the teeth 22 into the protrusion 3.

[0037] The tooth gap is the distance between the toothed disc 2 and the stator 1, as detailed in the reference. Figure 3 The tooth clearance refers to the radial distance from the tooth tip 21 of the tooth disk 2 to the inner circumferential surface 11 of the stator 1. "Hot state" refers to the state of the engine test piece under operating conditions. "Abrasive material" refers to materials that can be worn when the tooth 22 rubs against the protrusion 3, such as coatings or honeycomb structures, enabling the protrusion 2 to record wear marks.

[0038] During engine testing, the toothed disc 2 does not contact other parts of the stator 1, but only rubs against the protrusion 3. The protrusion 3 serves to record wear marks. After the engine test piece completes at least one full cycle, the toothed structure is disassembled, and the maximum radial penetration depth of the toothed disc 2 on the protrusion 3 is measured. This maximum penetration depth represents the maximum change in tooth clearance during engine operation, thus determining the optimal cold-state clearance value between the toothed disc 2 and the stator 1. When designing the toothed structure, the cold-state clearance between the toothed disc 2 and the stator 1 is designed to be greater than the calculated optimal cold-state clearance value. This ensures that the engine will not rub against the protrusion due to insufficient tooth clearance under different operating conditions, thus preventing any impact on engine safety performance.

[0039] The complete process of the engine test piece in this article refers to the entire process of the engine test piece starting from a stationary state to idle, then accelerating to the engine target operating condition (such as standard takeoff or high temperature takeoff), stabilizing for a certain period of time, decelerating to idle, and then stopping.

[0040] The gap change measuring device records wear marks by setting a protrusion 3 between the toothed disc 2 and the stationary component 1. Compared with directly rubbing the stationary component 1 against the toothed disc 2 and having the stationary component 1 record the wear marks itself, the contact area between the protrusion 3 and the toothed disc 2 is relatively small, and the rubbing vibration during the measurement process is smaller, thus having less impact on the gap change measurement value and the measurement result is more accurate.

[0041] In one embodiment, the toothed disc 2 is a rotating body, and multiple protrusions 3 are arranged on the stator 1 along the rotation direction 4 of the toothed disc 2. In engine testing, the placement direction of the clearance variation measuring device is as follows... Figure 3 As shown, the stator 1 has protrusions 3 in the four directions of up, down, left, and right, which makes the measured gap change more accurate. The gap change of the toothed disc 2 is different at different positions in the circumferential direction due to the influence of gravity. Therefore, setting the protrusions 3 on the stator 1 directly below the toothed disc 2 can obtain a more accurate maximum gap change.

[0042] exist Figure 3 In the embodiment shown, the stator 1 and the protrusion 3 are integral parts, and both the stator 1 and the protrusion 3 are honeycomb structures. Specifically, the stator 1 is a honeycomb ring, and the protrusion 3 is a honeycomb block of the same material as the stator 1. Multiple protrusions 3 are evenly distributed on the inner circumferential surface 11 of the stator 1 and protrude radially inward. The circumferential length of each protrusion 3 is about 5mm.

[0043] In other embodiments, the protrusion 3 may also be detachably provided on the stator 1 so that the protrusion 3 can be removed after the test to measure the cutting depth.

[0044] On the other hand, according to some embodiments of this application, a method for measuring the change in tooth clearance of an engine test piece under different operating conditions is also provided. This method for measuring the change in tooth clearance under hot conditions of the tooth structure includes the following steps:

[0045] Provide engine test components, including a toothed disc 2 and a stator component 1;

[0046] A protrusion 3 is provided on the stator 1. The protrusion 3 is made of a wearable material so that the toothed disc 2 can cut into the protrusion 3 when hot.

[0047] Assemble the toothed disc 2 and the stator component 1 to form a seal;

[0048] Start the engine test piece and complete at least one full cycle of operation, so that the toothed disc 2 and the protrusion 3 rub against each other under different working conditions of the engine test piece;

[0049] Disassemble the toothed disc 2 and the stator 1, measure and record the radial cutting depth of the toothed disc 2 on the protrusion 3. This cutting depth is the change in tooth clearance of the engine test piece under hot conditions.

[0050] Furthermore, according to some embodiments of this application, in order to obtain the optimal cold-state clearance value of the toothed structure to achieve a better sealing effect, a cold-state clearance design method for the toothed structure is also provided. The cold-state clearance design method for the toothed structure in an engine uses the aforementioned clearance change measurement method to measure the change in toothed clearance under hot conditions. This cold-state clearance design method further includes the following steps:

[0051] Before starting the engine test piece, determine the radial distance between the tooth tip 21 of the grating disk 2 and the protrusion 3, and record it as the first clearance value;

[0052] The cold clearance between the toothed disc 2 and the stator 1 is designed based on the measured first clearance value and the change in tooth clearance.

[0053] When assembling the toothed disc 2 and the stator 1, the gap between the tooth tip 21 of the toothed disc and the protrusion 3 on the stator 1 should be as close to 0mm as possible. For example, the tooth tip 21 of the toothed disc can be in contact with the surface of the protrusion 3, and there is no interaction force between the two. However, it is difficult to confirm whether there is an interaction force between the toothed disc 2 and the protrusion 3 during the assembly process. Therefore, in actual operation, there will be a certain gap between the tooth tip 21 of the toothed disc and the surface of the protrusion 3. This gap can be measured by measuring tools such as feeler gauges.

[0054] In engine testing, protrusion 3 is used to record the wear marks on the toothed disc 2 and protrusion 3. After the engine completes its full cycle of operation, the engine test piece is disassembled, and the radial penetration depth of the toothed disc 2 on multiple protrusions 3 is measured. The maximum penetration depth is the maximum change in tooth clearance during engine operation. Subtracting the first clearance value from this maximum change in tooth clearance gives the optimal cold-state clearance value between the toothed disc 2 and the stator 1. When designing the toothed structure, the clearance between the toothed disc 2 and the stator 1 is designed to be greater than the optimal cold-state clearance value obtained from the test. This ensures that the engine will not experience wear and tear due to excessively small tooth clearance under different operating conditions, thus preventing any impact on engine safety performance.

[0055] In one embodiment, the cutting depth on the protrusion 3 is measured by means of a micrometer or vernier caliper.

[0056] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for designing the cold clearance of a toothed structure, characterized in that, The gap change measurement device is used to measure the gap change of the tooth structure under hot conditions. The tooth structure includes a tooth disc and a stator. The tooth disc and the stator form a sealed structure. The gap change measurement device includes a protrusion on the stator. The protrusion is made of a wearable material so that when the tooth disc and the protrusion collide under hot conditions, the teeth of the tooth disc can cut into the protrusion. The method for measuring the change in the gap between the tooth ferrules under hot conditions is as follows: Provide engine test components, including geared discs and stator components; A protrusion is provided on the stator component, the protrusion being made of a wear-resistant material, so that the toothed disc can cut into the protrusion; Assemble the toothed disc and the stator to form a seal; Start the engine test piece and complete at least one full cycle of operation, so that the toothed disc and the protrusion rub against each other under different working conditions of the engine test piece; Disassemble the toothed disc and the stator, measure and record the radial cutting depth of the toothed disc on the protrusion, and the cutting depth is the change in tooth clearance of the engine test piece under hot conditions; The method for determining the cold clearance of the toothed structure includes the following steps: Before starting the engine test piece, determine the radial distance between the tooth tip of the grating disc and the protrusion, and record it as the first clearance value; The cold clearance between the toothed disc and the stationary component is designed based on the measured first gap value and the change in the tooth gap.

2. The cold clearance design method for the sieve structure as described in claim 1, characterized in that, The toothed disc is a rotating body, and multiple protrusions are arranged on the stator along the rotation direction of the toothed disc.

3. The cold clearance design method for the sieve structure as described in claim 1, characterized in that, The stationary component and the protrusion have a honeycomb structure.

4. The cold clearance design method for the sieve structure as described in claim 1, characterized in that, The stationary component and the protrusion are integral parts.

5. The cold clearance design method for the sieve structure as described in claim 1, characterized in that, The cutting depth is measured using a micrometer or vernier caliper.

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