Indirect measurement tool for assembly clearance of aircraft APU turbine rotor

Abstract

The utility model discloses an indirect measuring tool for an assembly clearance of an aircraft APU turbine rotor. The indirect measuring tool comprises a measuring disc and a bearing simulator. The outer diameter of the measuring disc is matched with the caliber of the APU combustion chamber shell; beam bones which are crossed are arranged in the measuring disc. A central sleeve is arranged at the central position of the measuring disc along the axial direction, each beam bone is provided with a measuring hole, and the radial distances from the measuring holes to the axis of the measuring disc are equal; and the bearing simulator is sleeved between the central rotating shaft of the APU and the central sleeve of the measuring disc. A circle of U-shaped avoiding grooves are evenly formed in the outer edge of the bottom face of the measuring disc in the circumferential direction. The measuring tool is used in cooperation with a depth gauge, can be used as an optimization substitute of an original factory tool, and can rapidly measure the distance Y from the top of a secondary turbine disc sealing ring to the upper surface of a measuring cross rod, thereby indirectly guaranteeing the design gap between a turbine rotor blade and a guide blade, effectively reducing the data deviation and the working intensity of workers, and being high in measuring efficiency and high in measuring precision. The measurement precision is high.

Description

Technical Field

[0001] This utility model relates to the field of aircraft ground maintenance technology, and in particular to an indirect measurement tool for the assembly clearance of an aircraft APU turbine rotor. Background Technology

[0002] The aircraft's APU (Auxiliary Power Unit) is a small-power turbojet engine. When the aircraft is parked on the ground, the aircraft needs to be powered and supplied with air by the APU in order to save energy from the aircraft's original power system. Therefore, the APU also needs to be inspected regularly.

[0003] Please also refer to the instruction manual appendix. Figures 1 to 3 A typical APU structure includes: a combustion chamber housing 100, a first-stage turbine guide vane 101 coaxially mounted within the combustion chamber housing, a first-stage turbine blade 102 (i.e., rotor), a second-stage turbine disk 103, and a first-stage guide vane housing 104. As part of APU maintenance, to ensure that the first-stage turbine guide vane 101 and the first-stage turbine blade 102 do not interfere with each other after installation, manufacturers require a predetermined distance H between the first-stage turbine guide vane 101 and the first-stage turbine blade 102. This predetermined distance is located inside the combustion chamber housing 100 and cannot be measured using conventional tools or methods.

[0004] Therefore, the aircraft manufacturer provides a dedicated original equipment manufacturer (OEM) measuring fixture in conjunction with an alternative measurement method to determine the "predetermined spacing". The OEM measuring fixture includes a measuring crossbar 200, a combination screw 201, and a support base 202; the measuring crossbar 200 has a measuring through hole 203 at its center, and the measuring crossbar 200 has symmetrically formed sliding grooves 204 along its length, with the combination screws 201 inserted into the two sliding grooves 204 respectively, and the support base 202 locks the combination screws 201 in the sliding grooves 204.

[0005] The method for modifying the measurement of the "predetermined spacing" value H using the original factory measuring fixture is as follows:

[0006] During measurement, the original measuring fixture is first assembled, and then the measuring crossbar 200 is placed on the upper edge of the opening of the combustion chamber housing 100. The combination screw 201 and the support seat 202 are adjusted so that the measuring crossbar 200 is placed flat on the combustion chamber housing 100. Then, the existing depth gauge 300 is inserted into the measuring through hole 203 of the measuring crossbar 200. The distance Y from the upper surface of the measuring crossbar 200 to the top of the second stage turbine disk 103 is obtained by measuring four different positions with the depth gauge 300. Then, the average value of Y is taken after four calculations, which can indirectly guarantee the "predetermined spacing" value H.

[0007] Using the original factory measuring fixtures and alternative methods to measure the "predetermined spacing" value H has the following drawbacks:

[0008] 1) Before each measurement, multiple parts of the original factory measuring fixture need to be assembled, which is cumbersome, inconvenient, and inefficient. In addition, the original factory measuring fixture parts are easy to be lost, which affects APU-related maintenance work.

[0009] 2) The original measuring tool needs to be moved to different positions multiple times (usually four times) to perform four measurements, which cannot guarantee the accuracy of the Y value and the measurement efficiency is low.

[0010] 3) When the measuring crossbar 200 is on the upper edge of the opening of the combustion chamber shell 100, it is only supported by the support seats 202 at both ends, which is unstable and causes a large measurement error.

[0011] 4) Frequent disassembly and reassembly of the original factory measuring fixtures will inevitably cause wear and tear on the parts, affecting the measurement accuracy. Utility Model Content

[0012] To address the shortcomings of existing technologies, this utility model provides an indirect measurement tool for the assembly clearance of aircraft APU turbine rotors, thereby overcoming the deficiencies in existing technologies.

[0013] To achieve the above objectives, this utility model provides the following technical solution:

[0014] An indirect measurement tool for the assembly clearance of an aircraft APU turbine rotor includes a measuring disc and a bearing simulator.

[0015] The outer diameter of the measuring disc is adapted to the diameter of the APU combustion chamber shell; the measuring disc is provided with intersecting beams inside; a central sleeve is provided at the center of the measuring disc along the axial direction; a measuring hole is opened on each beam, and the measuring hole is in the same direction as the axial direction of the measuring disc; and the radial distance from each measuring hole to the axis of the measuring disc is equal.

[0016] Furthermore, the bearing simulator is fitted between the APU central shaft and the central sleeve of the measuring disk.

[0017] Furthermore, a U-shaped clearance groove is uniformly arranged around the outer edge of the bottom surface of the measuring disk in the circumferential direction.

[0018] Preferably, the intersecting beams intersect with the outer wall of the central sleeve, and the bottom of the central sleeve protrudes to form a boss that protrudes from the bottom surface of the beams.

[0019] Preferably, the radial distance from each of the measuring holes to the axis of the measuring disk is consistent with the radius of the sealing boss of the secondary turbine disk.

[0020] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0021] 1) The aircraft APU turbine rotor assembly clearance in this case can be used as an optimized alternative to the original tooling. When used in conjunction with a depth gauge, this tool can quickly measure the distance Y from the top of the secondary turbine disk to the upper surface of the APU measuring disk, thereby indirectly ensuring the turbine rotor assembly clearance, effectively reducing data deviation and the workload of workers, with high measurement efficiency and high measurement accuracy.

[0022] 2) The indirect measurement tool for the assembly clearance of the aircraft APU turbine rotor in this case has a measuring disc that is an integral component, eliminating the need for numerous scattered accessories. The measurement process does not require frequent disassembly and assembly of accessories, resulting in high measurement efficiency. Furthermore, the tool is designed with a hollow style, which reduces weight and makes it easier to handle, further improving measurement efficiency.

[0023] 3) The aircraft APU turbine rotor assembly clearance indirect measurement tool in this case has a simple structure and low manufacturing cost. It integrates and simplifies the original OEM tooling, which is not only convenient to use but also avoids measurement errors. It has a significant improvement in work efficiency and reduces personnel fatigue, which is conducive to large-scale promotion in various aircraft maintenance bases.

[0024] To provide a clearer understanding of this invention, the preferred embodiments of this invention will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the internal structure of an APU in the background technology;

[0026] Figure 2 This is a schematic diagram of the original manufacturer's measuring tooling in the background technology;

[0027] Figure 3 This is a reference diagram showing the usage status of the original manufacturer's measuring tooling in the background technology;

[0028] Figure 4 , Figure 5 This is a schematic diagram of the measuring disc of this utility model;

[0029] Figure 6 This is a reference diagram showing the usage state of this utility model.

[0030] Attached image labels:

[0031] 1-Measuring disc, 2-Bearing simulator; 11-Beam frame, 12-Center sleeve, 13-Measuring hole, 14-Allowing groove; 100-Combustion chamber shell, 101-First stage turbine guide vane, 102-First stage turbine blade, 103-Second stage turbine disk, 104-First stage guide vane shell; 200-Measuring crossbar, 201-Combination screw, 202-Support seat, 203-Measuring through hole, 204-Slide groove; 300-Depth gauge. Detailed Implementation

[0032] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0033] Furthermore, if terms such as "first" or "second" are used for descriptive purposes only, they are mainly used to distinguish different devices, components or parts (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, components or parts, and should not be construed as indicating or implying relative importance.

[0034] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0035] Please also refer to Figure 1-6 This utility model provides an indirect measurement tool for the assembly clearance of an aircraft APU turbine rotor, including a measuring disk 1 and a bearing simulator 2.

[0036] The measuring disc 1 has an outer diameter that matches the diameter of the APU combustion chamber housing 100. The measuring disc 1 has intersecting beams 11 inside. A central sleeve 12 is provided at the center of the measuring disc 1 along the axial direction. The intersecting beams 11 intersect with the outer wall of the central sleeve 12. The bottom of the central sleeve 12 protrudes to form a boss protruding from the bottom surface of the beams 11.

[0037] Furthermore, each beam 11 is provided with a measuring hole 13, which is in the same direction as the axial direction of the measuring disk 1; and the radial distance from each measuring hole 13 to the axis of the measuring disk 1 is equal.

[0038] Preferably, in this embodiment, the radial distance from each measuring hole 13 to the axis of the measuring disk 1 is consistent with the radius of the sealing boss of the secondary turbine disk 103, which can be used with the depth gauge 300 to directly measure the Y value required in the maintenance manual.

[0039] The measuring hole 13 is used for the insertion of the depth gauge 300 to measure the distance Y from the top of the second-stage turbine disk 103 to the upper surface of the measuring disk 1. The four measuring holes 13 in different directions allow the depth gauge 300 to measure the Y value four times. By obtaining the accurate average value of the Y value, the "predetermined spacing" value H between the first-stage turbine guide vane 101 and the first-stage turbine blade 102 can be indirectly guaranteed.

[0040] Furthermore, a U-shaped clearance groove 14 is uniformly arranged around the outer edge of the bottom surface of the measuring disk 1. The clearance groove 14 is used to avoid a ring of positioning screws used to fix the first-stage guide vane housing 104 to the combustion chamber housing 100, thereby ensuring that the measuring disk 1 and the APU combustion chamber housing 100 are stably matched during the measurement process and ensuring measurement accuracy.

[0041] Bearing simulator 2 is a detachable and replaceable auxiliary centering sleeve. It is fitted between the APU central shaft and the central sleeve 12 of the measuring disk 1, ensuring coaxiality between the measuring disk 1 and the APU central shaft, thus guaranteeing measurement accuracy. By replacing the bearing simulator 2 with those of different wall thicknesses, it can be adapted to measure APUs of different diameters, enhancing the tool's compatibility.

[0042] The operating procedure for the indirect measurement tool for the assembly clearance of the aircraft APU turbine rotor in this case, under actual working conditions, is as follows:

[0043] 1) Assemble the first-stage turbine guide vane 101 and the first-stage turbine blade 102 and related components in the APU combustion chamber 100 according to the maintenance manual, and fix them with positioning screws;

[0044] 2) Place the measuring disk 1 on the opening of the APU combustion chamber 100, aligning the clearance groove 14 of the measuring disk 1 with the positioning screw, ensuring that the measuring disk 1 and the opening surface of the APU combustion chamber 100 are in close contact; at the same time, the APU central rotating shaft passes through the central sleeve 12 of the measuring disk 1, and the bearing simulator 2 is fitted on the APU central rotating shaft, so that the bearing simulator 2 is fitted between the APU central rotating shaft and the central sleeve 12 of the measuring disk 1, ensuring that the measuring disk 1 and the APU central rotating shaft are coaxial, thereby improving the measurement accuracy;

[0045] 3) Insert a depth gauge 300 into the measuring hole 13 of the measuring disk 1 one by one, measure the Y value four times and calculate the average value. By obtaining an accurate Y value, the "predetermined spacing" value H between the first-stage turbine guide vane 101 and the first-stage turbine vane 102 can be indirectly guaranteed.

[0046] Compared to existing technologies, the aircraft APU turbine rotor assembly clearance indirect measurement tool of this case can serve as an optimized alternative to the original factory tooling. When used in conjunction with a depth gauge, this tool can quickly measure the distance Y from the top of the secondary turbine disk to the upper surface of the measuring disk 1, effectively reducing data deviation and the workload of workers, with high measurement efficiency and high measurement accuracy.

[0047] The embodiments described above are merely examples of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these modifications and improvements all fall within the protection scope of this utility model.

Claims

1. An indirect measurement tool for the assembly gap of an aircraft APU turbine rotor, characterized in that: it comprises a measurement disc (1) and a bearing simulator (2); the outer diameter of the measurement disc (1) is adapted to the caliber of the APU combustion chamber housing (100); the measurement disc (1) is internally provided with cross intersecting beams (11); the measurement disc (1) is axially provided with a central sleeve (12) at the center position; each beam (11) is provided with a measurement hole (13); the measurement hole (13) is coaxial with the measurement disc (1); and the radial distance from each measurement hole (13) to the center of the measurement disc (1) is equal. The bearing simulator (2) is sleeved between the APU central rotating shaft and the central sleeve (12) of the measurement disc (1). The outer edge of the bottom surface of the measurement disc (1) is uniformly provided with a U-shaped avoidance groove (14) along the circumference.

2. An aircraft APU turbine rotor assembly gap indirect measurement tool according to claim 1, characterized in that: The cross intersecting beams (11) intersect with the outer wall of the central sleeve (12), and the bottom of the central sleeve (12) protrudes to form a boss protruding from the bottom surface of the beam (11).

3. An aircraft APU turbine rotor assembly gap indirect measurement tool according to claim 2, characterized in that: The radial distance from each measurement hole (13) to the center of the measurement disc (1) is consistent with the radius of the sealing boss of the secondary turbine disc (103).

4. An aircraft APU turbine rotor assembly gap indirect measurement tool according to claim 3, characterized in that: ​ 5. An aircraft APU turbine rotor assembly gap indirect measurement tool according to claim 3, characterized in that: ​

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