Special measuring tool for coaxiality of helicopter tail transmission shaft
By designing a helicopter tail drive shaft coaxial measurement tool including mounting base, dial meter fixing support, stainless steel stylus and multiple fixing methods, the problems of unfixed fixing of the dial meter, vulnerable stylus and inflexible fixing methods in existing tools are solved, and higher measurement accuracy and stability are achieved.
Patent Information
- Application Number
- CN202422030518.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-21
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-08-21
AI Technical Summary
The existing helicopter tail drive shaft coaxial measurement tools have problems such as unfixed fixation of the dial meter, vulnerable stylus, inconvenient measurement and inflexible fixation methods, resulting in inaccurate and unstable measurements.
A helicopter tail drive shaft coaxial measurement tool including a mount, a dial gauge, a fixing support, a fixing bolt and a stylus was designed. The dial meter fixing support and fixing bolts on the mounting base ensures that the dial meter is stable. Stylus made of stainless steel are used and stylus fixing nuts are installed to increase the stability of the stylus. At the same time, magic tape and optional magnets are added to the mount, providing multiple fixing methods to adapt to different measurement environments.
It improves the accuracy and stability of measurement, extends the service life of the stylus, reduces measurement errors, and enhances the fixing effect, especially on the tail drive shaft made of smooth or magnetic materials, ensuring the reliability and convenience of the measurement tool.
Smart Images
Figure CN222951673U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of helicopters, in particular to a special tool for measuring the coaxiality of a helicopter tail transmission shaft. Background Art
[0002] During the regular inspection of helicopters, in accordance with the maintenance recommendations, during each T-inspection (basic technical inspection) cycle, the helicopter's tail drive shaft needs to be disassembled and inspected in detail. After reinstallation, the coaxiality of the tail drive shaft must be tested. If any part of the main reducer, intermediate reducer, or tail reducer in the transmission system is disassembled, the coaxiality of the tail drive shaft also needs to be tested; the coaxiality needs to be measured at the diaphragm coupling at the connection point of the main reducer, intermediate reducer, tail reducer, and tail drive shaft, and the difference between the maximum and minimum values at each measuring position cannot exceed the limit value of 0.23mm. If the coaxiality of any point exceeds the limit value, the tail drive shaft will be eccentric when rotating at high speed, which will cause greater vibration. During the flight of the helicopter, the tail drive shaft works in a high-intensity vibration environment for a long time, which will cause greater wear on the high and low damping rings and support bearings. It will also accelerate the wear of the connecting flanges and splines of the tail drive shaft and the main reducer, intermediate reducer, and tail reducer. In severe cases, the tail drive shaft will break, resulting in an accident in which the aircraft is destroyed and people are killed.
[0003] When performing this operation in actual regular inspection work, the coaxiality detection tool used is a special tool, which consists of two parts: the mounting base and the measuring needle. During the actual measurement process, this tool was found to have many defects, mainly manifested in:
[0004] 1. The dial indicator used for measurement is stuck in the mounting base. Since the processing precision of the slot on the mounting base is rough and there is a lack of fixing measures, it is often necessary to stick paper tape in the slot to fix the dial indicator during use. During the measurement process, when the measuring tool rotates with the tail drive shaft, there will be a certain amount of activity clearance between the dial indicator and the mounting base, and it cannot be fixed securely.
[0005] 2. The measuring probe is made of softer iron rod and is fixed to the dial indicator probe by thread. Because the thread is thin, the probe thread will be damaged after several uses, and a certain gap will be created between the probe and the end of the dial indicator probe, causing the probe to often shift during measurement.
[0006] 3. The measuring needle is of a single type and is interfered by the rivets on the connecting flanges at both ends of the tail drive shaft, so some points cannot be measured.
[0007] 4. The meter base and the tail drive shaft are fixed with nylon wire clips or tied with ropes. This method is difficult to operate at the output end of the main reducer and is easy to loosen.
[0008] Affected by the above defects, when using this measuring tool, it often happens that after the tail shaft rotates to its original position, the dial indicator indication cannot be returned to zero, and the measurement results are inconsistent each time. Utility Model Content
[0009] The technical problem to be solved by the utility model is to provide a special coaxiality measuring tool for a helicopter tail transmission shaft in view of the above shortcomings.
[0010] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0011] A special measuring tool for the coaxiality of a helicopter tail transmission shaft comprises a mounting seat, a dial indicator, a dial indicator fixing support, fixing bolts and a measuring needle. The mounting seat is a rectangular parallelepiped and has a recessed arc surface at the bottom. The mounting seat is used to fix the dial indicator on the helicopter tail transmission shaft. The mounting seat is provided with a dial indicator fixing support, the dial indicator is provided on the dial indicator fixing support, the dial indicator is provided on the dial indicator fixing support, and the fixing bolts for fixing the dial indicator are provided on the dial indicator fixing support. The detection end of the dial indicator is provided with a measuring needle, and the detection end of the measuring needle is used to abut against the diaphragm coupling bolt of the tail transmission shaft; the mounting seat is also provided with two groups of magic tapes, the two groups of magic tapes are respectively provided at the front and rear ends of the mounting seat, and the magic tapes are used to tie the fixing seat to the tail transmission shaft; the bottom of the mounting seat is provided with an isolation cloth, and the bottom of the mounting seat is provided with a magnet, and the magnet is used to be adsorbed on the helicopter tail transmission shaft.
[0012] Furthermore, the measuring needle is a short measuring needle or a long measuring needle, and a measuring needle fixing nut is provided on the outer side of the threaded end of the measuring needle, and the measuring needle fixing nut is used to fix the measuring needle to the detection end of the dial indicator at any angle.
[0013] Furthermore, the middle part of the measuring needle is bent, and the threaded end of the measuring needle is parallel to the axis of the detection end.
[0014] Compared with the prior art, the utility model has the following advantages after adopting the above technical solution:
[0015] The utility model ensures the stability of the dial indicator on the mounting seat through the dial indicator fixing support and the fixing bolt on the mounting seat, avoids the shaking problem of the dial indicator in the traditional tool caused by the insufficient accuracy of the card slot or the lack of fixing measures, thereby improving the accuracy and stability of the measurement; the measuring needle is made of stainless steel, which has high hardness and wear resistance. Compared with the measuring needle made of traditional iron rod material, it can significantly extend the service life and reduce the measurement error caused by the wear of the measuring needle; at the same time, the design of the measuring needle fixing nut further ensures the stability of the measuring needle during the measurement process and prevents the displacement of the measuring needle; the magic tape and optional magnets added to the mounting seat provide a variety of fixing methods to adapt to different measurement environments; the flexibility of the magic tape makes installation and disassembly more convenient, and the addition of the magnet enhances the fixing effect, especially on the tail transmission shaft of smooth or magnetic material, which can effectively prevent the loosening of the mounting seat; a short measuring needle or a long measuring needle can be selected according to specific needs, and the measuring needle is an eccentric design with a bent middle part, and the detection end can move on a circle with the axis of the threaded end as the center, which can effectively avoid the interference of rivets.
[0016] The utility model is described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;
[0018] Figure 2 is a cross-sectional view of the mounting seat;
[0019] Figure 3 Schematic diagram of the probe structure.
[0020] In the accompanying drawings, the components represented by the reference numerals are listed as follows:
[0021] 1. Mounting base; 2. Dial indicator; 3. Fixed support; 4. Fixing bolt; 5. Probe; 501, short probe; 502, long probe; 6. Magic tape; 7. Isolation cloth; 8. Magnet; 9. Probe fixing nut. DETAILED DESCRIPTION
[0022] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.
[0023] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "clockwise", "counterclockwise", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.
[0024] like Figure 1-3 As shown, a special measuring tool for the coaxiality of a helicopter tail transmission shaft comprises a mounting seat 1, a dial indicator 2, a dial indicator fixing support 3, a fixing bolt 4 and a measuring needle 5. The mounting seat 1 is a rectangular parallelepiped and has a recessed arc surface at the bottom. The mounting seat 1 is used to fix the dial indicator 2 on the helicopter tail transmission shaft. The mounting seat 1 is provided with a dial indicator fixing support 3, the dial indicator 2 is provided on the dial indicator fixing support 3, the dial indicator 2 is provided on the dial indicator fixing support 3, the dial indicator fixing support 3 is provided with a fixing bolt 4 for fixing the dial indicator 2, the detection end of the dial indicator 2 is provided with a measuring needle 5, and the detection end of the measuring needle 5 is used to abut against the diaphragm coupling bolt of the tail transmission shaft; two groups of magic tapes 6 are also provided on the mounting seat 1, and the two groups of magic tapes 6 are respectively provided at the front and rear ends of the mounting seat 1, and the magic tapes 6 are used to tie the fixing seat to the tail transmission shaft; an isolation cloth 7 is provided at the bottom of the mounting seat 1, and a magnet 8 is provided at the bottom of the mounting seat 1, and the magnet 8 is used to be adsorbed on the helicopter tail transmission shaft.
[0025] As an implementation manner, the stylus 5 is a short stylus 501 or a long stylus 502 , and a stylus fixing nut 9 is provided on the outer side of the threaded end of the stylus 5 , and the stylus fixing nut 9 is used to fix the stylus 5 on the detection end of the dial indicator 2 at any angle.
[0026] As an implementation manner, the measuring needle 5 is bent in the middle, and the threaded end of the measuring needle 5 is parallel to the axis of the detection end.
[0027] Specifically, the best detection position between the detection end of the measuring needle 5 and the diaphragm coupling bolt can be found by rotating the measuring needle 5 .
[0028] The working process of the utility model is as follows: firstly, the dial indicator 2 is fixed on the dial indicator fixing support 3 by the fixing bolt 4, and then, according to the measuring part, a short measuring needle 501 or a long measuring needle 502 is selected and installed on the dial indicator 2, and then the mounting base is fixed to the appropriate position on the tail transmission shaft of the helicopter with the magic adhesive tape 6, and the top of the measuring needle 5 is pressed against the bolt of the diaphragm coupling of the tail transmission shaft, and the measuring needle fixing nut 9 is tightened to make the measuring needle 5 immobile and make the dial indicator 2 have a preload of 3mm to 4mm; after fixing the measuring tool, the tail transmission shaft is rotated one circle to check whether the pointer of the dial indicator 2 is zeroed, and if not, it is adjusted and fixed until the pointer of the dial indicator 2 is zeroed; then, the tail transmission shaft is rotated to measure the coaxiality value of each point, and each point is measured 2 to 3 times to observe whether the values are consistent, if they are consistent, the measurement is accurate, and if they are inconsistent, re-measure.
[0029] The above is an example of the best implementation of the utility model, and the parts not described in detail are common knowledge of ordinary technicians in this field. The protection scope of the utility model is based on the content of the claims, and any equivalent transformation based on the technical inspiration of the utility model is also within the protection scope of the utility model.
Claims
1. A special measuring tool for the coaxiality of a helicopter tail transmission shaft, characterized in that: The utility model comprises a mounting seat (1), a dial indicator (2), a dial indicator fixing support (3), fixing bolts (4) and a measuring needle (5); the mounting seat (1) is a rectangular parallelepiped and the bottom is an inwardly recessed arc surface; the mounting seat (1) is used to fix the dial indicator (2) on the tail transmission shaft of a helicopter; the mounting seat (1) is provided with a dial indicator fixing support (3); the dial indicator (2) is provided on the dial indicator fixing support (3); the dial indicator fixing support (3) is provided with fixing bolts (4) for fixing the dial indicator (2); the dial indicator fixing support (3) is provided with fixing bolts (4) for fixing the dial indicator (2); the dial indicator fixing support (3) is provided with fixing bolts (5) for fixing the dial indicator (2); the dial indicator fixing support (3) is provided with fixing bolts (5) for fixing the dial indicator (2); the dial indicator fixing support (3) is provided with fixing bolts (6) for fixing the dial indicator (2); the dial indicator fixing support (6) is provided with fixing bolts (7) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (8) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (9) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (10) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (11) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (12) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (13) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (14) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (11) for fixing the dial indicator (2); the dial indicator fixing support (7) is provided with fixing bolts (11) for fixing the dial indicator (2); the dial indicator fixing support (7 The detection end of the meter (2) is provided with a probe (5), and the detection end of the probe (5) is used to abut against the diaphragm coupling bolt of the tail transmission shaft; the mounting seat (1) is also provided with two groups of magic tapes (6), and the two groups of magic tapes (6) are respectively provided at the front and rear ends of the mounting seat (1), and the magic tapes (6) are used to tie the fixing seat to the tail transmission shaft; the bottom of the mounting seat (1) is provided with an isolation cloth (7), and the bottom of the mounting seat (1) is provided with a magnet (8), and the magnet (8) is used to be adsorbed on the tail transmission shaft of the helicopter.
2. A helicopter tail drive shaft coaxiality special measuring tool according to claim 1, characterized in that: The measuring needle (5) is a short measuring needle (501) or a long measuring needle (502), and a measuring needle fixing nut (9) is arranged on the outer side of the threaded end of the measuring needle (5), and the measuring needle fixing nut (9) is used to fix the measuring needle (5) on the detection end of the dial gauge (2) at any angle.
3. A helicopter tail drive shaft coaxiality special measuring tool according to claim 1, characterized in that: The measuring needle (5) is bent in the middle, and the threaded end of the measuring needle (5) is parallel to the axis of the detection end.