Device and method for measuring speed of combustion rotor of aero-engine

Abstract

The invention discloses an aero-engine combustion rotor speed measuring device and method, and belongs to the technical field of aero-engine part tests.The speed measuring device comprises a speed measuring sensor and a gear shaft, and the gear shaft is used for being rotatably arranged in an engine accessory transmission mechanism defined by a front casing and a rear casing in the axial direction; the first end of the gear shaft is sleeved with a first bearing, the second end of the gear shaft is used for being connected with a fuel rotor, the speed measurement sensor is used for being installed in a preset installation hole of a front case, and the speed measurement sensor measures the speed of the gear shaft and the fuel rotor by sensing the alternating interval frequency formed by the gear tooth crests and the gear tooth bottoms of the gear teeth. The speed measurement gear and the involute gear of the gear shaft for transmission in the accessory transmission mechanism are integrated, the speed measurement function and the transmission function are integrated, radial speed measurement is adopted, coaxial transmission is achieved, the number of parts is greatly reduced, and outfield maintenance is convenient to achieve.

Description

Technical Field

[0001] The present application relates to the technical field of aircraft engine component testing, and in particular, to an aircraft engine combustion rotor speed measuring device. Furthermore, the present application also relates to a combustion rotor speed measuring method comprising the aircraft engine combustion rotor speed measuring device. Background Art

[0002] The combustion rotor of an aviation gas turbine engine rotates at a high speed, making direct speed measurement difficult. Therefore, one method of measuring the combustion rotor speed is to install it on the accessory transmission device that requires a reduction gear to transmit engine accessories. The accessory transmission device mainly extracts power from the combustion rotor and transmits the various system accessories of the engine through gear reduction transmission. Therefore, there is a fixed transmission ratio between each gear and the combustion rotor. Among them, the combustion rotor speed is measured by installing a synchronously rotating tone wheel on the shaft within the accessory transmission device. The speed sensor measures the gear speed by sensing the alternating interval frequency formed by the tooth tops and tooth bottoms of the rectangular cross-section teeth on the tone wheel, and converts the combustion rotor speed into the transmission ratio between the shaft and the combustion rotor.

[0003] Although the speed is reduced by the accessory transmission, the tachometer still rotates at a relatively high speed. To ensure high speed measurement accuracy, the gap between the speed sensor's probe and the tips of the rectangular teeth on the tachometer requires precise control. This gap is called the tachometer clearance. The size of the tachometer clearance directly affects measurement accuracy. If it is too small, the speed sensor is easily affected by gear shaft vibration, resulting in wear and tear. However, if it is too large, it can lead to poor signal acquisition. Typically, the speed sensor is mounted on the accessory transmission casing, while the tachometer is mounted on the rotating shaft, which is in turn mounted to the casing via bearings. The axial dimensions of the casing, rotating shaft, and bearings all have machining tolerances, and a certain axial clearance is typically provided to ensure proper assembly of the rotating shaft. This structure results in a number of factors affecting the tachometer clearance. To ensure this tachometer clearance, existing aircraft engines incorporate adjustment shims between the speed sensor and the accessory transmission casing during assembly. The tachometer clearance is adjusted by grinding the adjustment shims.

[0004] When measuring the speed of the combustion rotor of an aviation gas turbine engine, a speed measuring tone wheel needs to be set on the rotating shaft, and the speed measuring gap needs to be adjusted by grinding and adjusting the gasket. This structure makes the accessory transmission device structure more complicated, the number of parts is greater, and it is inconvenient to grind and adjust the gasket in the field. Once the speed sensor fails, it is difficult to replace and adjust it in the field. Summary of the Invention

[0005] In view of at least one of the above technical problems, the present application provides an aircraft engine combustion rotor speed measuring device, which can integrate the speed measuring gear with the involute gear of the transmission gear shaft in the accessory transmission mechanism, integrate the speed measuring and transmission functions, adopt radial speed measurement and realize coaxial transmission, greatly reduce the number of parts, and facilitate field maintenance.

[0006] At the same time, the present application also provides a combustion rotor speed measurement method including the above-mentioned aircraft engine combustion rotor speed measurement device.

[0007] According to one aspect of the present application, a speed measuring device for an aircraft engine combustion rotor is provided, comprising a speed sensor and a gear shaft, wherein the gear shaft is rotatably mounted in a receiving cavity formed by a front casing and a rear casing, a first end of the gear shaft is sleeved with a first bearing, the first bearing being mounted in a first bearing hole preset in the front casing, a second end of the gear shaft being connected to the combustion rotor, a speed sensor being mounted in a mounting hole preset in the front casing, a probe of the speed sensor being arranged on the outside of the gear teeth of the gear shaft along a radial direction and facing the gear teeth, and the speed sensor being used to measure the speed of the gear shaft and the combustion rotor by sensing the alternating interval frequency formed by the tooth tops and tooth bottoms of the gear teeth.

[0008] In some embodiments of the present application, splines are provided at both ends of the gear shaft, the splines at the first end of the gear shaft are used to connect to the engine transmission accessories at the front end of the front casing, and the splines at the second end of the gear shaft are used to connect the gear shaft to the combustion rotor.

[0009] In some embodiments of the present application, the speed sensor includes a mounting portion, which is used to be installed in a mounting hole opened axially in the front casing. The axial direction of the mounting hole is parallel to the axial direction of the gear shaft, and the probe is mounted on the radial outside of the gear shaft through the mounting portion.

[0010] In some embodiments of the present application, a mounting platform is provided on the speed sensor, which is used to abut against the outer wall of the front receiver. A locking through hole is opened on the mounting platform, which is used to set a locking piece. The locking piece is used to pass through the locking through hole and cooperate with a preset locking screw hole on the front receiver to lock the speed sensor in the mounting hole of the front receiver.

[0011] In some embodiments of the present application, a sealing limit groove is provided on the inner wall of the mounting hole of the front receiver, and the sealing limit groove is used to set a sealing adjustment component, which is used to seal the sealing surface between the mounting part and the mounting hole. The sealing adjustment component is also used to adjust the installation centerline position of the mounting part.

[0012] In some embodiments of the present application, the sealing adjustment assembly includes a sealing sleeve, which is used to be mounted on the speed sensor. The sealing sleeve is also used to cooperate with the sealing limit groove to seal the speed sensor and the mounting hole. The wall thickness of the sealing sleeve is set unevenly so that the sealing sleeve can adjust the distance between the upper and lower sides of the speed sensor and the inner wall of the mounting hole during rotation, thereby adjusting the position of the center line of the speed sensor after installation.

[0013] In some embodiments of the present application, a plurality of convex teeth are provided in the peripheral annular array of the gear teeth, a gear tooth bottom is formed between each convex tooth, and the top of the convex tooth is set as the gear tooth top.

[0014] According to another aspect of the present application, a method for measuring the speed of a combustion rotor is provided, which uses the above-mentioned aircraft engine combustion rotor speed measuring device. The method for measuring the speed of a combustion rotor comprises the following steps: S100: Install the speed sensor in the mounting hole of the front casing, and align the probe with the gear teeth along the radial direction of the gear shaft; S200: Using the centerline of the first bearing hole of the front casing as a reference, measure the distance C between the installation centerline of the speed sensor mounting portion and the reference, measure the tooth tip circle diameter ΦD of the gear teeth, and measure the distance E between the probe and the installation centerline of the mounting portion; S300: Assume that the gap between the probe and the tooth top is the speed measurement gap △. The calculation formula of the speed measurement gap △ is: △=CD / 2-E S400: Adjust the size and tolerance of the distance C between the installation centerline of the speed sensor mounting portion on the front receiver and the relative reference, and / or adjust the size and tolerance of the tooth tip circle diameter ΦD of the measuring gear shaft, and / or adjust the distance E between the measuring probe and the installation centerline of the mounting portion, so as to control the speed measurement gap △ within a preset range; S500: Start the combustion rotor, and measure the speed of the gear shaft and the combustion rotor by sensing the alternating interval frequency formed by the tooth top and tooth bottom of the gear teeth through the speed sensor.

[0015] In some embodiments of the present application, in step S400, controlling the speed measuring gap Δ to be within a preset range specifically includes controlling the speed measuring gap Δ to be within a range of 0.4 mm to 0.6 mm.

[0016] In some embodiments of the present application, the aircraft engine combustion rotor speed measuring device also includes a sealing sleeve, the wall thickness of the sealing sleeve is unevenly set, the sealing sleeve is set on the mounting part of the speed sensor, the sealing sleeve is rotated to adjust the distance between the upper and lower sides of the mounting part and the inner wall of the mounting hole, and then the position of the mounting center line of the measuring mounting part is adjusted, and the distance c between the mounting center line driven by the measuring mounting part and the reference is measured. In step S300, c can also be used instead of C to calculate the speed measurement gap △=cD / 2-E.

[0017] This application has the following beneficial effects: The present application discloses an aircraft engine combustion rotor speed measuring device that uses a gear shaft rotatably mounted axially in an engine accessory transmission mechanism enclosed by a front casing and a rear casing as a speed measuring gear, eliminating a tone wheel structure, wherein the first end of the gear shaft is mounted in a first bearing hole preset in the front casing via a first bearing, and multiple dimensions required for radial speed measurement can be measured using the first bearing hole as a reference, eliminating the adjustment gasket, and the second end of the gear shaft can be connected to the combustion rotor; at the same time, a speed sensor is mounted in a mounting hole preset in the front casing, and the probe of the speed sensor is made perpendicular to the tooth tops of the gear teeth of the gear shaft, so that radial speed measurement can be performed, specifically, the speed of the gear shaft and the combustion rotor is measured by sensing the alternating interval frequency formed by the tooth tops and tooth bottoms of the gear teeth through the speed sensor. The combustion rotor test device of the present application has highly integrated overall functions and the number of parts is optimized and controlled to a minimum, providing support for the realization of a compact accessory transmission device structure.

[0018] The combustion rotor speed measurement method of the present application also has the above-mentioned beneficial effects. It also includes using the center line of the first bearing hole of the first bearing on the gear shaft as a reference, which can facilitate the measurement of the distance C between the center line of the mounting hole of the speed sensor on the front casing and the relative reference, the gear shaft tooth top circle diameter ΦD, and the distance E between the probe and the center line of the mounting hole of the speed sensor in sequence, and then calculating the gap between the probe and the gear tooth top, that is, the speed gap △, through the dimension chain. By controlling the speed gap △ within the preset range value, the requirement of stable speed measurement can be guaranteed, and no additional adjustment gasket is required. In specific applications, it is only necessary to ensure the processing accuracy of related parts such as the front casing and the gear shaft, that is, to achieve precise control of the speed gap △, which reduces the number of parts, shortens the time for assembly, grinding and adjusting gaskets, and makes it easier to replace and adjust the speed sensor of the engine in the field, thereby improving the field maintainability of the speed sensor.

[0019] Of course, any product implementing this application does not necessarily need to achieve all of the advantages described above. In addition to the purposes, features, and advantages described above, this application also has other purposes, features, and advantages. This application will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of this application. The exemplary embodiments and descriptions of this application are intended to explain this application and do not constitute an improper limitation on this application. In the accompanying drawings: Figure 1 It is a schematic diagram of the overall structure of the preferred embodiment of the present application; Figure 2 This is a structural diagram of a speed measuring sound wheel in the prior art; Figure 3 This is a schematic diagram of the prior art using a tachometer wheel and an adjustment shim to perform an ignition rotor test; Figure 4 This is a schematic diagram of the installation of the gear shaft in the preferred embodiment of the present application; Figure 5 It is a schematic diagram of various radial dimensions during speed measurement in a preferred embodiment of the present application; Figure 6 This is a schematic structural diagram of a speed sensor according to a preferred embodiment of the present application; Figure 7 This is a schematic diagram of the installation of the speed sensor when measuring speed in the preferred embodiment of the present application.

[0021] Legend: 100, rectangular tooth with cross section; 200, tooth top; 300, tooth bottom; 400, speed probe; 500, tone wheel; 600, adjustment shim; 700, gear to be measured; 1. First bearing; 2. Engine transmission accessories; 3. Front casing; 4. Speed sensor; 41. Probe; 42. Cable connector; 43. Mounting part; 5. Locking piece; 6. Sealing ring; 7. Rear casing; 8. Gear shaft; 81. Gear teeth; 811. Gear tooth top; 812. Gear tooth bottom; 9. Second bearing; 10. Spline; 11. First transmission gear; 12. Second transmission gear; 13. Center line of speed sensor; 14. Reference. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below with reference to the accompanying drawings, but the present application can be implemented in a variety of different ways defined and covered below.

[0023] A device for measuring the speed of an aircraft engine combustion rotor includes a speed sensor 4 and a gear shaft 8. The gear shaft 8 is rotatably mounted in a receiving cavity formed by a front casing 3 and a rear casing 7. A first end of the gear shaft 8 is sleeved with a first bearing 1, which is mounted in a first bearing hole preset in the front casing 3. The second end of the gear shaft 8 is connected to the combustion rotor. The speed sensor 4 is mounted in a mounting hole preset in the front casing 3. A probe 41 of the speed sensor 4 is radially arranged on the outside of the gear teeth 81 of the gear shaft 8 and facing the gear teeth 81. The speed sensor 4 is used to measure the speed of the gear shaft 8 and the combustion rotor by sensing the alternating interval frequency formed by the gear tooth top 811 and the gear tooth bottom 812 of the gear tooth 81.

[0024] Here, "gear shaft 8" refers to the shaft within the accessory drive mechanism that performs a transmission function. In some embodiments, gear shaft 8 includes a rotating shaft body and gear teeth 81. Gear teeth 81 are disposed on the rotating shaft body and are in the form of involute gears. Opposite ends of gear shaft 8 are connected to the front casing 3 and the rear casing 7, respectively, via a first bearing 1 and a second bearing 9. By ensuring that gear shaft 8 of the accessory drive mechanism not only performs the original function of driving accessories but also enables the combustion rotor speed measurement and precise control of the speed clearance, functional integration is achieved, the number of parts is effectively reduced, and the feasibility of the compact accessory drive structure is verified during speed testing.

[0025] The present application discloses an aircraft engine combustion rotor speed measuring device. A gear shaft 8 is axially rotatably mounted in an engine accessory transmission mechanism enclosed by a front casing 3 and a rear casing 7, serving as a speed measuring gear. The tone wheel structure is eliminated. The first end of the gear shaft 8 is mounted in a first bearing hole preset in the front casing 3 via a first bearing 1. Multiple dimensions required for radial speed measurement can be measured using the first bearing hole as a reference. The adjustment gasket 600 is eliminated, and the second end of the gear shaft 8 can be connected to the combustion rotor. Simultaneously, a speed sensor 4 is mounted in a mounting hole preset in the front casing 3, and the probe 41 of the speed sensor 4 is positioned perpendicular to the tooth tops 811 of the gear teeth 81 of the gear shaft 8. This allows for radial speed measurement. Specifically, the speed sensor 4 senses the alternating interval frequency formed by the tooth tops 811 and tooth bottoms 812 of the gear teeth 81 to measure the speed of the gear shaft 8 and the combustion rotor. The combustion rotor test device of the present application is highly functionally integrated, and the number of parts is optimized and controlled to a minimum, providing support for achieving a compact accessory transmission device structure.

[0026] Preferably, the outer peripheral annular array of the gear teeth 81 is provided with a plurality of convex teeth, a gear tooth bottom 812 is formed between each convex tooth, and the top of the convex tooth is set as a gear tooth top 811.

[0027] It should be noted that the speed sensor 4 senses the alternating interval frequency formed by the tooth tops 811 and tooth bottoms 812 of the gear teeth 81 to measure the speed. This speed measurement method is radial speed measurement. Since the accessory transmission mechanism on the aircraft engine is usually arranged laterally, the speed sensor 4 is installed axially to ensure that the aircraft engine accessories and accessory transmission mechanism are compact and have a small profile. This installation method of the speed sensor 4 is conducive to the coaxial transmission of two different accessories at both ends of the gear shaft 8. It only requires that the radial profile of the engine accessory 2 installed on the side of the speed sensor 4 is not larger than the radial profile of the gear on the gear shaft 8. Please refer to the appendix of the instruction manual for details. Figure 4 , that is, ΦB≯ΦA, which is conducive to the installation and disassembly of the speed sensor 4.

[0028] The instruction manual is attached Figure 2In the speed measurement method, if the speed sensor 4 is installed on the front receiver 3, there is no sufficient space outside the front receiver 3 for installing accessories. The accessories can only be installed on the rear receiver 7 side. The installation space is difficult to achieve coaxial transmission at both ends. In addition, the speed sensor 4 requires that its probe 41 be perpendicular to the radial direction of the tone wheel 500. Compared with the appendix of the specification, this application Figure 2 The speed measurement method in this embodiment eliminates the need for a separate speed-measuring tone wheel 500. Instead, the speed is measured directly using the involute gear teeth on the transmission gear shaft 8 within the accessory transmission mechanism. This integrates the speed measurement and transmission functions, simplifies the structure of gear shaft 8, and reduces the trial production cost of gear shaft 8. Furthermore, splines 10 are used at both ends of speed-measuring gear shaft 8 to connect to different accessories, achieving coaxial transmission at both ends, further reducing the number of transmission gear shafts within the accessory transmission mechanism.

[0029] Preferably, please refer to Figure 1 As shown, splines 10 are provided at both ends of the gear shaft 8. The spline 10 at the first end of the gear shaft 8 is used to connect with the engine transmission accessory 2 at the front end of the front casing 3, and the spline 10 at the second end of the gear shaft 8 is used to connect the gear shaft 8 to the combustion rotor.

[0030] It can be understood that by arranging splines 10 at both ends of the gear shaft 8, the two ends of the gear shaft 8 can be connected to the engine transmission accessory 2 and the combustion rotor respectively, thereby realizing coaxial transmission at both ends of the gear shaft 8, which can further reduce the number of gear shafts used for transmission in the accessory transmission mechanism, effectively streamline the number of parts of the test device, and help reduce failure rate and maintenance costs.

[0031] Preferably, please refer to Figure 1 As shown, the speed sensor 4 includes a mounting portion, which is used to be installed in a mounting hole opened in the axial direction of the front casing 3. The axial direction of the mounting hole is parallel to the axial direction of the gear shaft 8. The probe 41 is mounted on the radial outside of the gear shaft 8 through the mounting portion.

[0032] It can be understood that the mounting hole on the front receiver 3 is opened in the axial direction. On the one hand, the speed sensor 4 can be installed in the axial direction, which makes it convenient for the probe 41 to point vertically to the gear teeth 81 of the gear shaft 8 to achieve radial speed measurement; on the other hand, the mounting hole on the front receiver 3 can also be integrated with the special hole for gear borescope inspection in the accessory transmission mechanism, so that the mounting hole can realize multiple functions, reducing the number of machined holes on the front receiver 3 or the rear receiver 7, and reducing the number of parts used to block the special hole for gear borescope inspection, that is, using the speed sensor 4 as a blocking piece for the special inspection hole, and there is no need to worry about the influence of repeated disassembly and installation of the speed sensor 4 on the speed gap △, thereby improving the field maintainability of the accessory transmission mechanism.

[0033] It should be noted that the accessory drive mechanism of a gas turbine shaft engine is typically located in the upper front portion of the engine for ease of maintenance, forming a separate unit structure with the accessories mounted thereon. During field maintenance, it is necessary to inspect the working condition of the gears within the accessory drive mechanism. Typically, a dedicated inspection hole is provided in the accessory drive mechanism to facilitate borescope inspection. This hole is typically located above and outside the front casing 3 or the rear casing 7 for easy access by maintenance personnel. However, the present application integrates the mounting hole for the speed sensor 4 with the dedicated gear borescope inspection hole, eliminating the gear borescope inspection hole and optimizing the casing structure. This reduces processing costs, improves the overall rigidity of the casing, and reduces the number of sealing components, thereby lowering maintenance costs.

[0034] In this preferred embodiment, the center line of the speed sensor 4 remains parallel to the center line of the gear shaft 8, preventing the cable connected to the tail of the speed sensor 4 through the cable connector 42 from exceeding the outline of the aircraft engine. It also facilitates the bundling of aircraft engine cables and prevents misinstallation through cable length because engine cables are usually arranged below the rear casing 7 of the accessory transmission device.

[0035] Preferably, please refer to Figure 1 As shown, a mounting platform is provided on the speed sensor 4, which is used to abut against the outer wall of the front casing 3. A locking through hole is opened on the mounting platform, and the locking through hole is used to set a locking member 5. The locking member 5 is used to pass through the locking through hole and cooperate with the preset locking screw hole on the front casing 3 to lock the speed sensor 4 in the mounting hole of the front casing 3.

[0036] It can be understood that by tightening the mounting platform against the outer wall of the front casing 3 through the locking member 5, the speed sensor 4 can be stably locked and limited, the working stability of the speed sensor 4 is ensured, and the speed sensor 4 can be easily disassembled and assembled through the locking member 5.

[0037] Preferably, a plurality of locking through holes are opened on the mounting platform, and the speed sensor 4 is stably locked and limited on the front casing 3 by means of a plurality of locking members 5 cooperating with the locking through holes.

[0038] Optionally, the locking member 5 is a bolt or a screw. By using standard parts, disassembly and assembly operations are facilitated, and procurement and maintenance and replacement costs are reduced.

[0039] Preferably, a sealing limit groove is provided on the inner wall of the mounting hole of the front casing 3, and the sealing limit groove is used to set a sealing adjustment component, which is used to seal the sealing surface between the mounting portion and the mounting hole, and the sealing adjustment component is also used to adjust the installation centerline position of the mounting portion 43.

[0040] As will be appreciated, the seal adjustment assembly seals the sealing surface between speed sensor 4 and the mounting hole, preventing leakage of lubricating oil used to lubricate gears, bearings, and splines within the accessory transmission mechanism. The seal adjustment assembly also adjusts the centerline position of speed sensor 4 after installation in the mounting hole, further facilitating adjustment of the speed gap Δ to meet speed measurement requirements.

[0041] In this preferred embodiment, the sealing adjustment assembly includes a sealing sleeve, which is used to be sleeved on the mounting portion 43. The sealing sleeve is also used to cooperate with the sealing limit groove to seal the mounting portion 43 and the mounting hole. The wall thickness of the sealing sleeve is set unevenly so that the sealing sleeve can adjust the distance between the radial sides of the mounting portion 43 and the inner wall of the mounting hole during rotation, thereby adjusting the installation centerline position of the mounting portion 43.

[0042] It can be understood that, due to the non-uniform setting of the wall thickness of the sealing sleeve, a section with the thickest wall thickness can be set on the sealing sleeve, and the wall thickness on both sides of the thickest wall thickness section gradually becomes thinner. In this way, when the sealing sleeve is set on the speed sensor 4, the position of the speed sensor center line 13 of the speed sensor 4 in the mounting hole can be changed by rotating the sealing sleeve to adjust the distance between the center line of the speed sensor 4 and the center line of the first bearing hole serving as the reference 14, thereby achieving the effect of changing the speed gap △, so that the speed gap △ is adjusted to a range that meets the speed measurement requirements.

[0043] Optionally, the sealing adjustment assembly further includes a sealing ring 6 , which is sleeved on the outer wall of the speed sensor 4 to enhance the sealing effect.

[0044] Preferably, please refer to Figure 1 As shown, the outer peripheral annular array of the gear teeth 81 is provided with a plurality of protruding teeth, a gear tooth bottom 812 is formed between each protruding tooth, and the top of the protruding tooth is set as a gear tooth top 811.

[0045] It can be understood that by respectively arranging the first bearing 1 and the second bearing 9 at both ends of the gear shaft 8 , the gear shaft 8 can be stably installed and the stability of the gear shaft 8 during rotation can be ensured.

[0046] According to another aspect of the present application, a method for measuring the speed of a combustion rotor is provided, which uses the above-mentioned aircraft engine combustion rotor speed measuring device. The method for measuring the speed of a combustion rotor comprises the following steps: S100: Install the speed sensor 4 in the mounting hole of the front casing 3, and align the probe 41 radially inwardly with the gear teeth 81 of the gear shaft 8; S200: Using the centerline of the first bearing hole of the front casing 3 as a reference 14, measure the distance C between the installation centerline of the mounting portion 43 of the speed sensor 4 and the reference 14, measure the diameter ΦD of the tooth tip 811 of the gear tooth 81, and measure the distance E between the probe 41 and the installation centerline of the mounting portion 43; S300: Assume that the gap between the probe 41 and the gear tooth top 811 is the speed measuring gap △. The calculation formula of the speed measuring gap △ is: △=CD / 2-E S400: Adjust the size and tolerance of the distance C between the installation centerline of the mounting portion 43 of the speed sensor 4 on the front receiver 3 and the relative reference 14, and / or adjust the size and tolerance of the addendum diameter ΦD of the gear teeth 81 of the measuring gear shaft 8, and / or adjust the distance E between the measuring probe 41 and the installation centerline of the mounting portion 43, so as to control the speed measurement gap Δ within a preset range; S500: Start the combustion rotor, and measure the speed of the gear shaft 8 and the combustion rotor by sensing the alternating interval frequency formed by the tooth top 811 and the tooth bottom 812 of the gear tooth 81 through the speed sensor 4.

[0047] The combustion rotor speed measurement method of the present application also has the above-mentioned beneficial effects. It also includes using the center line of the first bearing hole of the first bearing on the gear shaft 8 as a reference 14, which can facilitate the sequential measurement of the distance C between the center line of the mounting hole of the speed sensor 4 on the front casing 3 and the relative reference 14, the tooth top circle diameter ΦD of the gear tooth 81 of the gear shaft 8, and the distance E between the probe 41 and the center line of the mounting hole of the speed sensor 4. Then, the gap between the probe 41 and the tooth top 811, i.e., the speed measurement gap △, is calculated through a dimension chain. By controlling the speed measurement gap △ within a preset range, the requirement of stable speed measurement can be ensured, eliminating the need for additional adjustment shims 600. In specific applications, it is only necessary to ensure the processing accuracy of related parts such as the front casing 3 and the gear shaft 8, that is, to achieve precise control of the speed measurement gap △. This reduces the number of parts, shortens the time for assembling and grinding the adjustment shims 600, and makes it easier to replace and adjust the speed sensor 4 in the engine field, thereby improving the field maintainability of the speed sensor 4.

[0048] Preferably, in step S400, controlling the speed measuring gap Δ to be within a preset range specifically includes controlling the speed measuring gap Δ to be within a range of 0.4 mm to 0.6 mm.

[0049] It should be noted that the present application enables control of the speed clearance Δ between the probe 41 of an aircraft engine's combustion rotor speed sensor 4 and the speed gear, i.e., the gear shaft 8, in the accessory transmission mechanism. Because this application utilizes radial speed measurement, the speed clearance Δ is primarily calculated based on radial dimensions and tolerances. Using the centerline of the mounting hole of the first bearing 1 on the front casing 3 as a reference, the radial play of the first bearing 1 is small, and its effect on the speed clearance Δ is negligible. By adjusting various dimensions and their tolerances, specifically ensuring the machining accuracy of the relevant parts, the speed clearance Δ is controlled within a range of 0.4mm to 0.6mm, meeting the requirements for precise speed measurement and effectively controlling the effects of various vibrations and component vibrations during speed measurement. The use of an additional adjustment shim 600 is unnecessary; only the machining accuracy of the relevant parts is required to achieve precise control of the speed clearance Δ. This reduces the number of parts, shortens the time required to assemble and sharpen the adjustment shim 600, and facilitates replacement and adjustment of the speed sensor 4 in the field, improving its field maintainability.

[0050] Preferably, the aircraft engine combustion rotor speed measuring device also includes a sealing sleeve, the wall thickness of the sealing sleeve is unevenly set, the sealing sleeve is set on the mounting portion 43 of the speed sensor 4, the sealing sleeve is rotated to adjust the distance between the upper and lower sides of the mounting portion 43 and the inner wall of the mounting hole, and then the position of the installation center line of the measuring mounting portion 43 is adjusted, and the distance c between the installation center line driven by the measuring mounting portion 43 and the reference 14 is measured. In step S300, c can also be used instead of C to calculate the speed measurement gap △=cD / 2-E.

[0051] It can be understood that due to the non-uniform setting of the wall thickness of the sealing sleeve, when the sealing sleeve is mounted on the speed sensor 4, the position of the center line of the speed sensor 4 in the mounting hole can be changed by rotating the sealing sleeve to adjust the distance c between the center line of the speed sensor 4 and the center line of the first bearing hole serving as the reference 14, and c is used instead of C to calculate the speed gap △=cD / 2-E. The speed gap △ can be changed by adjusting the rotation angle of the sealing sleeve, so that the speed gap △ is adjusted to a range that meets the speed measurement requirements. The adjustment method is simpler, and the constant replacement or grinding of related parts to make the speed gap △ reach the preset value can be reduced, thereby effectively reducing the difficulty of controlling the speed gap △ and greatly improving the efficiency of the speed measurement test.

[0052] It should be noted that the direction of the probe 41 of the speed sensor 4 of this application is perpendicular to the center line of the speed sensor 4, please refer to Figure 6As shown, this ensures radial speed measurement. Conventional speed sensors have their probes collinear with the sensor center. However, for small and medium-sized aircraft engines, the speed sensor 4 is often placed outside (above, to the left, or to the right) the engine's accessory transmission gearbox to facilitate assembly and disassembly. If this speed sensor 4 is placed above the accessory transmission gearbox, its profile will extend beyond the engine height. Furthermore, the cable connector 42 at the rear of the speed sensor 4 increases the engine's height profile. If this speed sensor 4 is placed to the left or right of the accessory transmission gearbox, it can only measure the outermost gears in the entire gear train. This not only limits the placement of the speed sensor 4 but also causes the speed sensor 4 to extend beyond the engine's profile in the width direction. Therefore, a configuration where the probe 41 of the speed sensor 4 is collinear with the center of the speed sensor 4, when used for radial speed measurement, is detrimental to engine installation and maintenance within the aircraft's engine bay. Therefore, one approach is to install the speed sensor 4 coaxially with the transmission gear center, using a dedicated sound wheel 500 to sense signals axially.

[0053] The structure of the speed sensor 4 probe 41 of the present application being perpendicular to the sensor center can still be installed in the same direction as the center of the gear shaft 8, reducing the external contour of the engine and facilitating the installation of the engine in the aircraft. Please refer to Figure 7 As shown. Furthermore, the speed measuring gear can be any transmission gear in the accessory transmission gear train (it can be any one of the first transmission gear 11, the second transmission gear 12, or the gear teeth 81 of the gear shaft 8). The installation position of the speed sensor 4 is not restricted, facilitating the layout of other mounting accessories on the accessory transmission gearbox. When the engine system accessory profile or layout needs to be adjusted, only the position of the speed sensor 4 mounting hole on the casing needs to be adjusted, thereby saving a significant amount of installation space for other system accessories.

[0054] Furthermore, the speed measurement structure of the present application eliminates the need for other rotating structures attached to the gear shaft 8, thereby not changing the natural frequency of the gear and having no effect on the vibration of the high-speed rotating accessory transmission gear. This facilitates engine modification and remodeling, reduces the number of parts that need to be adjusted during engine modification and remodeling, lowers development costs, and offers high versatility. For example: Figure 7 The gear teeth 81 of the middle gear shaft 8 also serve as a speed measuring gear. When the spatial profile of a system accessory on the left side of the speed sensor 4 increases, the speed sensor 4 can no longer be installed above the existing gear teeth 81 on the casing. The casing profile above the second transmission gear 12 can be increased, and the mounting hole of the speed sensor 4 on the casing is moved to the right. At the same time, in order to ensure the gap between the speed sensor 4 probe 41 and the gear tooth top and ensure the speed measurement accuracy, the speed measuring gear of the speed sensor 4 is adjusted from the gear teeth 81 to the second transmission gear 12. The second transmission gear 12 does not require any structural adjustment to meet the needs of engine improvement and modification.

[0055] In summary, the present application uses the gear shaft 8, which plays a transmission role, as a speed measuring gear, eliminates the tone wheel structure, and realizes an integrated structure for measuring the engine gas rotor speed by using the alternating interval frequency formed by the gear tooth top 811 and the gear tooth bottom 812 of the gear shaft 8 on the engine accessory transmission mechanism; adopts radial speed measurement to realize the coaxial transmission of the gear shaft 8, reducing the number of gears in the accessory transmission mechanism; adopts multiple methods to control the speed measurement gap, eliminating the adjustment gasket 600; integrates the mounting hole of the speed sensor 4 with the special hole for gear borescope inspection, eliminating the special hole for gear borescope inspection and other structures. The speed measurement structure with multiple integrated functions of the present application makes installation easier, has fewer parts, is lighter, has shorter maintenance time, and lowers cost, and provides support for the realization of a compact accessory transmission mechanism structure.

[0056] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0057] This article uses specific examples to illustrate the principles and implementation methods of this application. The above examples are only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as protected by this application.

Claims

1. An aircraft engine combustion rotor speed measuring device, characterized in that: The invention comprises a speed sensor (4) and a gear shaft (8), wherein the gear shaft (8) is rotatably mounted in a receiving cavity formed by a front casing (3) and a rear casing (7), a first end of the gear shaft (8) is sleeved with a first bearing (1), the first bearing (1) is mounted in a first bearing hole preset in the front casing (3), a second end of the gear shaft (8) is connected to a combustion rotor, and the speed sensor (4) is mounted in a mounting hole preset in the front casing (3), a probe (41) of the speed sensor (4) is arranged on the outside of the gear teeth (81) of the gear shaft (8) along the radial direction of the gear shaft (8) and is arranged toward the gear teeth (81), and the speed sensor (4) is used to measure the speed of the gear shaft (8) and the combustion rotor by sensing the alternating interval frequency formed by the gear tooth top (811) and the gear tooth bottom (812) of the gear tooth (81).

2. The aircraft engine combustion rotor speed measuring device according to claim 1, characterized in that: Both ends of the gear shaft (8) are provided with splines (10), the splines (10) at the first end of the gear shaft (8) are used to connect with the engine transmission accessory (2) at the front end of the front casing (3), and the splines (10) at the second end of the gear shaft (8) are used to connect the gear shaft (8) to the combustion rotor.

3. The aircraft engine combustion rotor speed measuring device according to claim 1, characterized in that: The speed sensor (4) includes a mounting portion (43), the mounting portion (43) being used to be mounted in a mounting hole opened in the axial direction of the front casing (3), the axial direction of the mounting hole being parallel to the axial direction of the gear shaft (8), and the probe (41) being mounted on the radially outer side of the gear shaft (8) through the mounting portion (43).

4. The aircraft engine combustion rotor speed measuring device according to claim 3, characterized in that: The speed sensor (4) is provided with a mounting platform, the mounting platform is used to abut against the outer wall of the front casing (3), a locking through hole is provided on the mounting platform, the locking through hole is used to set a locking member (5), the locking member (5) is used to pass through the locking through hole and cooperate with a locking screw hole preset on the front casing (3) to lock and fix the speed sensor (4) in the mounting hole of the front casing (3).

5. The aircraft engine combustion rotor speed measuring device according to claim 3, characterized in that: The inner wall of the mounting hole of the front casing (3) is provided with a sealing limit groove, the sealing limit groove is used to set a sealing adjustment component, the sealing adjustment component is used to seal the sealing surface between the mounting portion (43) and the mounting hole, and the sealing adjustment component is also used to adjust the installation centerline position of the mounting portion (43).

6. The aircraft engine combustion rotor speed measuring device according to claim 5, characterized in that: The sealing adjustment assembly includes a sealing sleeve, which is used to be sleeved on the mounting portion (43). The sealing sleeve is also used to cooperate with the sealing limit groove to seal the mounting portion (43) and the mounting hole. The wall thickness of the sealing sleeve is set to be uneven so that the sealing sleeve can adjust the distance between the radial sides of the mounting portion (43) and the inner wall of the mounting hole during the rotation process, thereby adjusting the installation centerline position of the mounting portion (43).

7. The aircraft engine combustion rotor speed measuring device according to claim 1, characterized in that: The outer peripheral annular array of the gear teeth (81) is provided with a plurality of convex teeth, a gear tooth bottom (812) is formed between each convex tooth, and the top of the convex tooth is set as the gear tooth top (811).

8. A method for measuring the speed of a combustion rotor, characterized in that: Using the aircraft engine combustion rotor speed measuring device according to any one of claims 1 to 7, a combustion rotor speed measuring method comprises the following steps: S100: Install the speed sensor (4) in the mounting hole of the front casing (3), and align the probe (41) radially inwardly with the gear teeth (81) of the gear shaft (8); S200: Using the center line of the first bearing hole of the front casing (3) as the reference (14), measure the distance C between the installation center line of the installation portion (43) of the speed sensor (4) and the reference (14), measure the diameter ΦD of the tooth top (811) of the gear (81), and measure the distance E between the probe (41) and the installation center line of the installation portion (43); S300: Assume that the gap between the probe (41) and the tooth top (811) is the speed measuring gap △. The calculation formula of the speed measuring gap △ is: △=CD / 2-E S400: Adjust the size and tolerance of the distance C between the installation center line of the installation portion (43) of the speed sensor (4) on the front casing (3) and the relative reference (14), and / or adjust the size and tolerance of the tooth top circle diameter ΦD of the gear teeth (81) of the measuring gear shaft (8), and / or adjust the distance E between the measuring probe (41) and the installation center line of the installation portion (43), so as to control the speed measurement gap △ within a preset range; S500: The combustion rotor is started, and the speed of the gear shaft (8) and the combustion rotor is measured by sensing the alternating interval frequency formed by the tooth top (811) and the tooth bottom (812) of the gear (81) through the speed sensor (4).

9. A combustion rotor speed measurement method according to claim 8, characterized in that: In step S400, controlling the speed measuring gap Δ to be within a preset range specifically includes controlling the speed measuring gap Δ to be within a range of 0.4 mm to 0.6 mm.

10. A combustion rotor speed measurement method according to claim 8, characterized in that: The aircraft engine combustion rotor speed measuring device further comprises a sealing sleeve, the wall thickness of the sealing sleeve being non-uniformly set, the sealing sleeve being mounted on the mounting portion (43) of the speed measuring sensor (4), the sealing sleeve being rotated to adjust the distance between the upper and lower sides of the mounting portion (43) and the inner wall of the mounting hole, and then adjusting the position of the mounting center line of the measuring mounting portion (43), and measuring the distance c between the mounting center line driven by the mounting portion (43) and the reference (14), and in step S300, the speed measuring gap △=cD / 2-E is calculated by replacing C with c.

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