A coaxiality measuring device and method for aircraft engines

Abstract

The invention discloses a coaxiality measuring device and method for an aeroengine, wherein the measuring device comprises two groups of brackets, a measuring shaft, a first bearing, a second bearing, two groups of locking structures and a measuring gauge; the measuring shaft is horizontally mounted between the two groups of brackets and is detachably connected to the two groups of brackets, and two bearing stop surfaces are arranged on a shaft section on one side of the measuring shaft; the first bearing and the second bearing are slidably arranged on the measuring shaft and are located outside the two bearing stop surfaces; the two groups of locking structures are arranged at the two bearing stop surfaces; the measuring gauge is used to obtain circular runout data at a first fulcrum bearing cavity; the invention first uses two of the three fulcrum bearing cavities to find a reference axis, and then measures the runout of the third fulcrum bearing cavity when rotating around the reference axis, and reads the coaxiality of the three fulcrum bearing cavities from the runout conditions, thereby realizing the three-point coaxiality measurement in the aeroengine assembly process, and avoiding the problem of accuracy influence caused by the reassembly process.

Description

Technical Field

[0001] The invention relates to the technical field of aeroengine measurement, and in particular to a coaxiality measurement device and method for an aeroengine. Background Art

[0002] Coaxiality is essential to ensure the stability and efficiency of aircraft engines because it can reduce vibration and unbalanced forces, thereby reducing wear and extending engine life. In the design and manufacture of modern aircraft engines, the control of coaxiality usually relies on precision manufacturing processes and strict quality control standards. The coaxiality detection process is affected by many factors, including the operator's skills, the accuracy of the measuring equipment, the processing status of the workpiece, the choice of measurement method, and environmental conditions.

[0003] For a three-pivot aircraft engine, it includes three pivot bearing cavities, such as Figure 1 As shown in the figure, the first fulcrum bearing cavity is arranged at the front end of the compressor, and the second fulcrum bearing cavity and the third fulcrum bearing cavity are arranged in the rear bearing support respectively. When the coaxiality of the three-fulcrum aircraft engine is detected, it is generally necessary to detect the coaxiality of the three fulcrum bearing cavities. Since the position of the second fulcrum bearing cavity is in the middle, it is difficult for the measuring tool to approach when measuring the coaxiality. Therefore, the traditional detection method is to separate the compressor stator part and the bearing support, such as Figure 2 As shown, the first fulcrum bearing cavity is separated from the second fulcrum bearing cavity and the third fulcrum bearing cavity, and then the coaxiality between the first fulcrum bearing cavity and the second fulcrum bearing cavity is detected, and then the coaxiality between the second fulcrum bearing cavity and the third fulcrum bearing cavity is detected, and finally the whole is reassembled. Since the bearing support and the stator of the last stage compressor are connected by interference fit, there is a certain deformation error during the assembly process. Therefore, it is difficult to ensure the accuracy after separate detection and reassembly, and it is difficult to achieve 100% restoration, so there is a problem of limited accuracy of the measurement results. Summary of the invention

[0004] The purpose of the present invention is to provide a coaxiality measuring device and method for aircraft engines, so as to solve the problem that the traditional method of distributed measurement and reassembly is difficult to ensure the accuracy when measuring the coaxiality of three-point aircraft engines.

[0005] The technical solution of the present invention is: A coaxiality measuring device for an aircraft engine comprises two groups of brackets, a measuring shaft, a first bearing, a second bearing, two groups of locking structures and a measuring gauge: the measuring shaft is horizontally mounted between the two groups of brackets and is detachably connected to the two groups of brackets, and two bearing stop surfaces are arranged on a shaft section on one side of the measuring shaft; a first bearing and a second bearing are arranged on the measuring shaft and are located outside the two bearing stop surfaces, and the first bearing and the second bearing can slide along the axial direction of the measuring shaft; two groups of locking structures are arranged at the two bearing stop surfaces, and are used to lock the positions of the first bearing and the second bearing when the first bearing and the second bearing slide to the two bearing stop surfaces, so that the first bearing supports the second fulcrum bearing cavity, and the second bearing supports the third fulcrum bearing cavity; the measuring gauge is used to obtain circular runout data at the first fulcrum bearing cavity.

[0006] Preferably, as a further improvement of the present invention, the locking structure includes a thread and a locking nut opened in the circumferential direction of the measuring shaft, the thread is located outside the bearing stop surface, and the locking nut is detachably connected to the measuring shaft via the thread.

[0007] Preferably, as a further improvement of the present invention, the thread is a self-locking thread.

[0008] Preferably, as a further improvement of the present invention, the measuring shaft is a four-section stepped shaft, which is provided with a first shaft section, a second shaft section, a third shaft section and a fourth shaft section from left to right, the diameters of the first shaft section and the fourth shaft section are equal and smaller than the diameter of the second shaft section, the diameter of the second shaft section is smaller than the diameter of the third shaft section, the two bearing stop surfaces are arranged on both sides of the third shaft section, and the threads in the two groups of the locking structures are arranged on both side ends of the third shaft section.

[0009] Preferably, as a further improvement of the present invention, the bracket includes a support rod and a support base fixed at the bottom of the support rod, the top of the support rod is provided with a U-shaped groove, and the first axis segment and the fourth axis segment of the measuring axis are horizontally inserted into the U-shaped grooves in the two groups of brackets respectively.

[0010] Preferably, as a further improvement of the present invention, a friction layer for preventing the measuring shaft from rotating is provided on the inner side of the groove wall of the U-shaped groove.

[0011] The present invention also discloses a coaxiality measurement method for an aeroengine, which is implemented using the above coaxiality measurement device and includes the following steps: The connecting flanges between the compressor stator parts in the three-point aircraft engine are split to keep the last stage compressor stator connected to the bearing support; The first bearing is inserted into the measuring shaft and moved to abut against the bearing stop surface on the right side, and the position of the first bearing is locked by a set of locking structures; Insert the measuring shaft from the side of the bearing support provided with the third fulcrum bearing cavity, and stop moving after the side wall of the third fulcrum bearing cavity abuts against the first bearing; The second bearing is inserted into the measuring shaft and moved to abut against the bearing stop surface on the left side, and the position of the second bearing is locked by another set of locking structures; The compressor stator portion provided with the first fulcrum bearing cavity is passed through the measuring shaft and reconnected with the last stage compressor stator via a connecting flange; The measuring shaft equipped with the three-pivot aircraft engine is horizontally mounted between the two sets of brackets, so that the compressor stator part of the three-pivot aircraft engine can rotate freely around the first bearing and the second bearing; A relative measurement reference axis is formed by the second fulcrum bearing cavity and the third fulcrum bearing cavity. A measuring tool is used to measure the runout data of the first fulcrum bearing cavity when the compressor stator part rotates around the reference axis, thereby realizing three-point coaxiality measurement.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 0. Utilizing the principle that two points can determine a straight line, first use two of the three pivot bearing cavities to find a reference axis for relative measurement, then measure the runout of the third pivot bearing cavity when rotating around the reference axis, and read the coaxiality of the three pivot bearing cavities from the runout, thereby realizing the three-point coaxiality measurement during the assembly of aircraft engines. Compared with traditional detection methods, the present application realizes the measurement of the entire assembly on the measuring shaft, without the need to split the bearing support and the compressor stator part for detection before assembly, thus avoiding the problem of accuracy affected by the reassembly process.

[0013] 2. The device has a simple structure, clear principle, high measurement accuracy, is easy to use, and saves time and effort.

[0014] 3. The engine's posture during measurement is close to the actual usage state. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The structure diagram of the existing three-pivot aircraft engine is shown in FIG. Figure 2 It is a schematic diagram of disassembly and assembly of an existing three-pivot aircraft engine when measuring coaxiality; Figure 3 It is a three-dimensional structural schematic diagram of a coaxiality measuring device for an aircraft engine according to the present invention; Figure 4 It is a schematic diagram of an installation of the present invention when measuring the coaxiality of a three-pivot aircraft engine; Figure 5Another schematic diagram of the installation of the present invention when measuring the coaxiality of a three-pivot aircraft engine; Figure 6 The present invention is a schematic structural diagram of the coaxiality measurement of a three-pivot aircraft engine. DETAILED DESCRIPTION

[0016] The following is combined with Figure 3 To the attached Figure 6 , the specific implementation methods of the present invention are described in detail. In the description of the invention, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0017] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features; in the description of the invention, unless otherwise specified, "plurality" means two or more.

[0018] Example 1 like Figure 3 As shown, an embodiment of the present invention provides a coaxiality measuring device for an aircraft engine, comprising two groups of brackets 1, a measuring shaft 2, a first bearing 41, a second bearing 42, two groups of locking structures and a measuring gauge 6: the measuring shaft 2 is horizontally mounted between the two groups of brackets 1 and is detachably connected to the two groups of brackets 1, and two bearing stop surfaces 3 are provided on one side shaft section of the measuring shaft 2; the first bearing 41 and the second bearing 42 are arranged on the measuring shaft 2 and are located on the outside of the two bearing stop surfaces 3, and the first bearing 41 and the second bearing 42 can slide along the axial direction of the measuring shaft 2; the two groups of locking structures are arranged at the two bearing stop surfaces 3, and are used to lock the positions of the first bearing 41 and the second bearing 42 when the first bearing 41 and the second bearing 42 slide to the two bearing stop surfaces 3, so that the first bearing 41 supports the second fulcrum bearing cavity, and the second bearing 42 supports the third fulcrum bearing cavity; the measuring gauge 6 is used to obtain the circular runout data at the first fulcrum bearing cavity.

[0019] It should be noted that the stators in the compressor stator part 7 in the three-pivot aircraft engine are connected by connecting flanges 71. In this embodiment, in order to solve the problem that the accuracy is difficult to ensure after separate detection and reassembly, a measuring device is specially set up. The stators on both sides of the connecting flange 71 are first split, and the last-stage compressor stator is kept connected to the bearing support 8, and the bearing support 8 is passed through the measuring shaft 2. The positioning function of the installation position of the first bearing 41 and the second bearing 42 is achieved through the cooperation of the two sets of locking structures and the two bearing stop surfaces 3, so that the first bearing 41 and the second bearing 42 can support the second fulcrum bearing cavity and the third fulcrum bearing cavity, and then the remaining stators with the first fulcrum bearing cavity are installed through the connecting flange 71. After being assembled into a whole, the measuring shaft 2 is mounted on two groups of brackets 1. By utilizing the principle that two points can determine a straight line, the second fulcrum bearing cavity and the third fulcrum bearing cavity are first used as a reference axis for relative measurement, and then the circular runout data of the first fulcrum bearing cavity when rotating around the reference axis is measured by the measuring gauge 6. The coaxiality of the three fulcrum bearing cavities is read out from the circular runout data, thereby realizing the three-point coaxiality measurement during the assembly of the aircraft engine. Compared with the traditional detection method, there is no need to disassemble the bearing support and the compressor stator part for detection before assembly. The present application only disassembles and assembles the compressor stator part 7 during the installation on the measuring shaft 2, and finally measures the assembled whole. Therefore, the problem of accuracy influence caused by the reassembly process can be avoided.

[0020] The measuring tool 6 includes a micrometer with a magnetic base, which is fixed on the measuring shaft 2 by adsorption through the magnetic base during measurement, and the micrometer is used for measurement.

[0021] Specifically, the locking structure includes a thread and a locking nut 5 opened in the circumferential direction of the measuring shaft 2. The thread is located on the outer side of the bearing stop surface 3. The locking nut 5 is detachably connected to the measuring shaft 2 through the thread. The setting of the locking nut 5 can realize a threaded detachable connection, which is not only convenient for installation but also can utilize the thread engagement for locking and positioning.

[0022] Furthermore, in order to prevent external vibration interference during measurement, which may cause the locking nut 5 to rotate and cause positioning deviation, the thread adopts a self-locking thread, such as a triangular thread, a rectangular thread, etc.

[0023] Furthermore, in order to facilitate installation, Figure 3As shown, the measuring shaft 2 is a four-section stepped shaft, which is provided with a first shaft section 21, a second shaft section 22, a third shaft section 23 and a fourth shaft section 24 from left to right. The diameters of the first shaft section 21 and the fourth shaft section 24 are equal and smaller than the diameter of the second shaft section 22. The diameter of the second shaft section 22 is smaller than the diameter of the third shaft section 23. Two bearing stop surfaces 3 are arranged on both sides of the third shaft section 23. The threads in the two groups of locking structures are arranged at the two side ends of the third shaft section 23. The first shaft section 21 and the fourth shaft section 24 are arranged to facilitate connection with the two groups of brackets 1 and keep them horizontal. The second shaft section 22 is arranged to facilitate the measuring tool 6 to extend into the first fulcrum bearing cavity for measurement during detection.

[0024] Among them, the bracket 1 includes a support rod 11 and a support base 12 fixed at the bottom of the support rod 11. A U-shaped groove is opened on the top of the support rod 11. The first shaft segment 21 and the fourth shaft segment 24 of the measuring axis 2 are horizontally inserted into the U-shaped grooves in the two groups of brackets 1 respectively. Such an arrangement makes it easy to detachably mount the measuring axis 2 on the U-shaped groove and support it using two support rods 11.

[0025] Furthermore, in order to prevent the measuring shaft 2 from rotating when the aircraft engine is rotated to perform three-point coaxiality measurement, a friction layer is provided on the inner side of the groove wall of the U-shaped groove to prevent the measuring shaft 2 from rotating. The friction layer can increase the friction between the measuring shaft 2 and the U-shaped groove to resist the rotational torque. The friction layer can be made of carbon fiber or ceramic reinforced resin-based material.

[0026] Example 2 This embodiment is based on embodiment 1. Figures 4 to 6 As shown, a coaxiality measurement method for an aircraft engine is disclosed, which is implemented using the above-mentioned coaxiality measurement device and includes the following steps: The connecting flange 71 between the compressor stator parts 7 in the three-point aircraft engine is split so that the last stage compressor stator remains connected to the bearing support 8; The first bearing 41 is inserted into the measuring shaft 2 and moved to abut against the bearing stop surface 3 on the right side, and the position of the first bearing 41 is locked by a set of locking structures; Insert the measuring shaft 2 from the side of the bearing support 8 where the third fulcrum bearing cavity is provided, and stop moving after the side wall of the third fulcrum bearing cavity abuts against the first bearing 41; The second bearing 42 is inserted into the measuring shaft 2 and moved to abut against the bearing stop surface 3 on the left side, and the position of the second bearing 42 is locked by another set of locking structures; The compressor stator portion provided with the first fulcrum bearing cavity is passed through the measuring shaft 2 and reconnected to the last stage compressor stator via the connecting flange 71; The measuring shaft 2 equipped with the three-pivot aircraft engine is horizontally mounted between the two sets of brackets 1, so that the compressor stator part of the three-pivot aircraft engine can rotate freely around the first bearing 41 and the second bearing 42; A relative measurement reference axis is formed by the second fulcrum bearing cavity and the third fulcrum bearing cavity. The measuring gauge 6 is used to measure the runout data of the first fulcrum bearing cavity when the compressor stator part 7 rotates around the reference axis, thereby realizing three-point coaxiality measurement.

[0027] The above disclosures are only several preferred specific embodiments of the present invention. However, the embodiments of the present invention are not limited thereto. Any changes that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A coaxiality measuring device for an aircraft engine, comprising two sets of brackets (1), characterized in that: Also includes: A measuring shaft (2) is horizontally mounted between the two sets of brackets (1) and is detachably connected to the two sets of brackets (1); two bearing stop surfaces (3) are provided on one side shaft section of the measuring shaft (2); A first bearing (41) and a second bearing (42) are arranged on the measuring shaft (2) and are located outside the two bearing stop surfaces (3); the first bearing (41) and the second bearing (42) are capable of sliding along the axial direction of the measuring shaft (2); Two sets of locking structures are arranged at the two bearing stop surfaces (3) and are used to lock the positions of the first bearing (41) and the second bearing (42) when the first bearing (41) and the second bearing (42) slide to the two bearing stop surfaces (3), so that the first bearing (41) supports the second fulcrum bearing cavity and the second bearing (42) supports the third fulcrum bearing cavity; The measuring tool (6) is used to obtain the circular runout data at the first fulcrum bearing cavity.

2. The coaxiality measuring device for an aircraft engine according to claim 1, characterized in that: The locking structure comprises a thread formed on the circumference of the measuring shaft (2) and a locking nut (5), wherein the thread is located outside the bearing stop surface (3), and the locking nut (5) is detachably connected to the measuring shaft (2) via the thread.

3. The coaxiality measuring device for an aircraft engine according to claim 2, characterized in that: The thread is a self-locking thread.

4. The coaxiality measuring device for an aircraft engine according to claim 3, characterized in that: The measuring shaft (2) is a four-section stepped shaft, and is provided with a first shaft section (21), a second shaft section (22), a third shaft section (23) and a fourth shaft section (24) in sequence from left to right; the diameters of the first shaft section (21) and the fourth shaft section (24) are equal and smaller than the diameter of the second shaft section (22); the diameter of the second shaft section (22) is smaller than the diameter of the third shaft section (23); the two bearing stop surfaces (3) are arranged on both sides of the third shaft section (23); and the threads in the two sets of locking structures are arranged on both side ends of the third shaft section (23).

5. The coaxiality measuring device for aircraft engines according to claim 4, characterized in that: The support (1) comprises a support rod (11) and a support base (12) fixed to the bottom of the support rod (11); a U-shaped groove is provided at the top of the support rod (11); and a first shaft section (21) and a fourth shaft section (24) of the measuring shaft (2) are horizontally inserted into the U-shaped grooves in the two sets of support (1), respectively.

6. The coaxiality measuring device for an aircraft engine according to claim 5, characterized in that: A friction layer is provided on the inner side of the groove wall of the U-shaped groove for preventing the measuring shaft (2) from rotating.

7. A method for measuring the coaxiality of an aircraft engine, implemented using the coaxiality measuring device according to any one of claims 1 to 6, characterized in that: The following steps are involved: The connecting flange (71) between the compressor stator parts (7) in the three-pivot aircraft engine is split so that the last stage compressor stator remains connected to the bearing support (8); The first bearing (41) is inserted into the measuring shaft (2) and moved until it abuts against the bearing stop surface (3) located on the right side, and the position of the first bearing (41) is locked by a set of locking structures; The measuring shaft (2) is inserted into the bearing support (8) from one side of the bearing cavity provided with the third fulcrum until the side wall of the bearing cavity of the third fulcrum abuts against the first bearing (41) and stops moving; The second bearing (42) is inserted into the measuring shaft (2) and moved until it abuts against the bearing stop surface (3) located on the left side, and the position of the second bearing (42) is locked by another set of locking structures; The compressor stator portion provided with the first fulcrum bearing cavity is passed through the measuring shaft (2) and reconnected to the last-stage compressor stator via a connecting flange (71); A measuring shaft (2) equipped with a three-pivot aircraft engine is horizontally mounted between two sets of brackets (1), so that a compressor stator part (7) of the three-pivot aircraft engine can rotate freely around a first bearing (41) and a second bearing (42); A relative measurement reference axis is formed by the second fulcrum bearing cavity and the third fulcrum bearing cavity, and the runout data of the first fulcrum bearing cavity when the compressor stator part (7) rotates around the reference axis is measured using a measuring gauge (6), thereby achieving three-point coaxiality measurement.

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