Coaxiality installation and calibration method for folding transmission shaft of helicopter

Abstract

The invention belongs to a helicopter assembly technology, and relates to a coaxiality installation and calibration method for a folding transmission shaft of a helicopter. A folding shaft is limited through a folding shaft length adjusting tool, a spring in the folding shaft is compressed through thread tightening, the length of the folding shaft is further shortened, the length of the folding shaft is made to be smaller than the assembling distance between the two sides, after the folding shaft is smoothly installed, the adjusting tool is gradually loosened, the spring is gradually loosened, the concave-convex fluted disc ends are meshed, and one end of a flange plate is in butt joint and fastened. After the folding shaft is mounted, a group of laser emission receivers are mounted at the two ends of the folding shaft through a bracket; through a disc paddle, the two laser emission receivers receive motion tracks of the two laser beams, actually-measured axes at the two ends of the folding shaft are simulated, the angle and position deviation of the two axes are calculated, and a model is generated; and calculating the thickness of an adjusting gasket below a folding shaft connecting end product according to fitting of the deviation model and a theoretical axis, and completing installation of the folding shaft according to a final state. After the folding shaft is installed, the acting force of the spring is released in the shaft system, and coaxiality calibration is carried out. The influence of the internal spring force on the axis calibration result after the folding shaft is installed in a traditional pre-calibration mode is avoided, and the calibration accuracy and the assembly efficiency are remarkably improved.

Description

Technical Field

[0001] The invention belongs to helicopter assembly technology and relates to a coaxiality installation and calibration method for a foldable transmission shaft of a helicopter. Background Art

[0002] The existing helicopter transmission shaft calibration technology measurement methods are widely used in the domestic and foreign helicopter equipment manufacturing industries. The "wire measurement method" and "ordinary optical measurement method" are used to install and adjust the tail transmission system. The "wire measurement method" uses a tooling bracket to install the wire rope to the center of the flange end face of the reference shaft, and uses the wire as the measurement reference line to adjust the axis of the adjusted system component and the axis of the reference shaft to be coaxial. The "ordinary optical measurement method" uses a tooling bracket to install the optical calibration mirror and the calibration target plate on the center of the flange end face of the adjusted system component and the center of the flange end face of the reference shaft, respectively, and uses the optical eyepiece to simulate the axis. The axis is adjusted to be coaxial with the axis of the reference shaft. These two methods are pre-calibration before the transmission shaft is installed, and the wire rope or optical calibration mirror needs to be installed on the center line of the transmission shaft for calibration.

[0003] The tail beam of a certain type of helicopter tail structure has a folding function, and the tail drive shaft system adapts to add a quick folding shaft at the front end of the middle reducer. For the folding tail drive shaft, the folding process of the folding tail drive shaft is to compress / restore the internal spring of the folding shaft to open and close the folding interface. The folding shaft surface is a set of concave and convex scale plates, which are subjected to spring pressure after installation and bite to transmit torque; the spring generates an axial force of about 800N in the system, which cannot be compressed and assembled by manpower, and there is a risk of collapse during installation. Summary of the invention

[0004] The invention provides a method for installing and calibrating the coaxiality of a foldable transmission shaft of a helicopter. During the installation and adjustment process of the helicopter transmission shaft, the influence of the spring force in the foldable tail transmission shaft can be overcome to ensure the installation of the tail transmission shaft. After the foldable tail transmission shaft is installed, the coaxiality calibration is performed to avoid the influence of the spring force on the calibration result, thereby ensuring the installation accuracy of the foldable transmission shaft system.

[0005] Technical solution: To achieve the above-mentioned purpose, the present invention proposes a method for installing the coaxiality of a helicopter foldable transmission shaft, wherein the foldable shaft is limited by adjusting the length of the foldable shaft, and the internal spring of the foldable shaft is compressed by tightening the thread, so as to further shorten the length of the foldable shaft to be smaller than the assembly spacing on both sides. After the foldable shaft is successfully installed, the adjusting tool is gradually loosened, the spring is gradually relaxed, the concave and convex toothed disc ends are meshed, and one end of the flange is butted and fastened;

[0006] After the folding axis is installed, a group of laser transmitters and receivers are installed at both ends of the folding axis through the bracket; the motion trajectories of the two laser beams are received by the disk propeller and the two laser transmitters and receivers to simulate the actual axis lines at both ends of the folding axis, calculate the angle and position deviation of the two axis lines and generate a model; according to the deviation model and the theoretical axis fitting, the thickness of the adjustment gasket under the product at the connection end of the folding axis is calculated, and the installation of the folding axis is completed according to the final state.

[0007] Furthermore, the adjustment tooling includes a first fastener, a second fastener, and an adjusting bolt; the first fastener is fastened and connected to one end of the foldable transmission shaft, and the second fastener is fastened and connected to the other end of the foldable transmission shaft; the distance between the first fastener and the second fastener is adjusted by the adjusting bolt, thereby realizing the telescopic length of the foldable transmission shaft.

[0008] Furthermore, during installation, the rigid support, the intermediate reducer and the peelable gasket installed under the rigid support and the intermediate reducer are first pre-assembled on the machine using process bolts to preliminarily fix the rigid support and the intermediate reducer.

[0009] Furthermore, in the ground state, two clamping rings on the foldable drive shaft adjustment tooling are used to clamp the axial surfaces at both ends of the foldable drive shaft. By adjusting the protruding length of the bolts connecting the two clamping rings on the special tooling, the position of the clamping rings on the axial surfaces at both ends can be adjusted, thereby overcoming the elastic force of the internal spring of the foldable drive shaft, realizing compression of the foldable drive shaft, and shortening the wheelbase of the foldable drive shaft.

[0010] Furthermore, the adjusted foldable transmission shaft is subjected to an on-machine test, the protruding length of the bolts connecting the two retaining rings on the tooling is adjusted, the foldable transmission shaft is connected to the rigid support and the intermediate reducer by bolts, and the tooling is disassembled.

[0011] Furthermore, during the on-board test, it is determined whether it can be installed between the rigid support and the middle reducer; the length of the foldable transmission shaft is slightly smaller than the distance between the rigid support and the middle reducer to ensure that it can be freely inserted between the rigid support and the middle reducer.

[0012] Furthermore, a set of laser transmitting and receiving devices are respectively installed on the flange end face of the output end of the rigid support and the flange end face of the input end of the foldable transmission shaft through the adapter tool.

[0013] Furthermore, the adapter tooling is a laser transmitter and receiver tooling bracket, including a card plate and a retractable adjustment shaft arranged above the card plate, the card plate is used for fixing the lower end, and the retractable adjustment shaft above the card plate is connected to the laser transmitter and receiver.

[0014] The advantages of the present invention are: a method for installing and calibrating the coaxiality of a foldable transmission shaft of a helicopter, wherein the foldable transmission shaft system includes a rigid support, a section of foldable transmission shaft, a middle reducer and other transmission system components, and the foldable transmission shaft is installed between the rigid support and the middle reducer. By using a special tooling for the foldable transmission shaft to overcome the elastic force of the spring in the foldable transmission shaft, the foldable transmission shaft is compressed to ensure the installation of the foldable transmission shaft; after the foldable transmission shaft is installed, the tooling is disassembled to release the elastic force of the spring in the shaft system, and a group of laser transmitters and receivers are installed on the axial surfaces of the flange at the output end of the rigid support and the flange at the input end of the middle reducer through the tooling bracket, and the motion trajectories of the two laser beams are received on the two laser transmitters and receivers through the disc propeller, and the measured axes at both ends of the foldable shaft are simulated, and the angles and position deviations of the two axes are calculated and a model is generated. According to the deviation model and the theoretical axis fitting, the thickness of the peelable gasket below the rigid support and the middle reducer at the connection end of the foldable shaft is calculated, and the positions of the rigid support and the middle reducer are adjusted according to the coaxiality result, and finally the coaxiality requirements of the transmission shaft system are achieved.

[0015] 1. By designing the folding shaft installation tooling, the length of the folding shaft can be stably compressed and adjusted, and the length of the folding shaft is adjusted to adapt to the distance with the connection end, thereby realizing the installation of the folding shaft;

[0016] 2. A calibration method for the folding shaft after installation is proposed. After the folding shaft is installed, the spring force is released in the shaft system to perform coaxiality calibration. This avoids the influence of the internal spring force on the axis calibration result after the folding shaft is installed in the traditional pre-calibration method, thereby improving the accuracy of calibration;

[0017] 3. Compared with the traditional adjustment method, the coaxiality laser calibration method of the helicopter foldable transmission shaft system of the present invention realizes the digital collection and visual adjustment of the coaxiality of the foldable transmission shaft system, thereby reducing the uncontrollable factors of human beings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the installation of the rigid support and the middle reducer;

[0019] Figure 2 Adjustment tool for foldable drive shaft

[0020] Figure 3 It is a schematic diagram of the connection between the foldable transmission shaft adjustment tooling and the foldable transmission shaft;

[0021] Figure 4 Schematic diagram of laser transmitter and receiver installation;

[0022] In the figure, 1-rigid support, 2-middle reducer, 3-half retaining ring, 4-bolt assembly, 5-foldable transmission shaft adjustment bolt, 6-foldable transmission shaft, 7-laser transmitter and receiver A, 8-laser transmitter and receiver B, 9-laser transmitter and receiver tooling bracket, 10-foldable transmission shaft adjustment tooling. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Traditional transmission shaft system calibration widely uses calibration methods such as "wire measurement method" and "ordinary optical measurement method". All of them are pre-calibrated before the shaft system is installed, and then installed in situ after calibration. There is a risk of deviation in the calibration result due to assembly deviation. Because the folding shaft uses spring elastic force to connect other components, the coaxiality calibration result deviation is large due to the gear disc gap and spring deformation after the elastic force is released. The pre-calibration method cannot meet the coaxiality accuracy requirements after the folding shaft is installed.

[0025] The present invention aims at the typical characteristics of the folding shaft. By using the folding shaft adjustment tool to overcome the elastic force of the spring in the folding shaft, the folding shaft is compressed to an appropriate length to ensure the installation of the folding shaft. After the folding shaft is installed, the tool is disassembled to release the elastic force of the spring in the shaft system. A set of laser transmitters and receivers are installed on the shaft surface at the output end of the rigid support and the input end of the middle reducer through the tool bracket. Through the disk propeller, the two laser transmitters and receivers receive the motion trajectory of the two laser beams, simulate the measured axis at both ends of the folding shaft, calculate the angle and position deviation of the two axis lines and generate a model. According to the deviation model and the theoretical axis fitting, the thickness of the rigid support at the connection end of the folding shaft and the peelable gasket below the middle reducer are calculated, and the position of the rigid support and the middle reducer is adjusted according to the coaxiality result, and finally the coaxiality requirement of the transmission shaft system is achieved.

[0026] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 A method for installing and calibrating the coaxiality of a helicopter foldable transmission shaft system, wherein the foldable transmission shaft system includes a rigid support 1, a section of foldable shaft 6, a middle reducer 2 and other transmission system components, and the foldable transmission shaft is installed between the rigid support 1 and the middle reducer 2. The foldable transmission shaft adjustment tool 10 is used to overcome the elastic force of the spring in the foldable transmission shaft, compress the foldable transmission shaft, and ensure the installation of the foldable transmission shaft; a laser transmitting and receiving device is used to realize the calibration of the foldable transmission shaft after installation to ensure the coaxiality requirements of the transmission shaft system. The specific implementation of the method includes the following steps:

[0027] Step 1: pre-assemble the rigid support 1, the middle reducer 2 and the peelable gasket installed under the rigid support and the middle reducer on the machine using process bolts.

[0028] Step 2: In the ground state, use the two clamping rings 3 on the foldable drive shaft adjustment tooling 10 to clamp the axial surfaces at both ends of the foldable drive shaft, and fix them with the bolt assembly 4; by adjusting the extended length of the foldable drive shaft adjustment bolt 5 connecting the two clamping rings on the special tooling, the position of the clamping rings on the axial surfaces at both ends can be adjusted, thereby overcoming the elastic force of the internal spring of the foldable drive shaft, realizing the compression of the foldable drive shaft, and shortening the wheelbase of the foldable drive shaft.

[0029] Step three, conduct an on-machine test on the foldable transmission shaft, adjust the protruding length of the bolts connecting the two retaining rings on the tooling, connect the foldable transmission shaft to the rigid support and the intermediate reducer with bolts, and disassemble the tooling.

[0030] Step 4: Install a group of laser transmitters and receivers (laser transmitters and receivers A7 and laser transmitters and receivers B8) on the flange end faces of the output end of the rigid support and the flange end faces of the input end of the folding transmission shaft through the adapter tool. The laser transmitters and receivers have Bluetooth transmitting and receiving functions. Through the disk paddle, the two laser transmitters and receivers receive the motion trajectories of the two laser beams, simulate the measured axes at both ends of the folding shaft, calculate the angles and position deviations of the two axes, and generate a model. According to the deviation model and the theoretical axis fitting, calculate the thickness of the rigid support at the connection end of the folding shaft and the peelable gasket below the middle reducer, adjust the position of the rigid support and the middle reducer according to the coaxiality result, and finally achieve the coaxiality requirements of the transmission shaft system. When calibrating the coaxiality, the adapter tool is a laser transmitter and receiver tool bracket 9, including a card plate and a retractable adjustment shaft arranged above the card plate. The card plate is used to fix the lower end, and the retractable adjustment shaft above the card plate is connected to the laser transmitter and receiver.

[0031] Embodiment: After the method of the invention is applied in the assembly process of a certain type of helicopter, the difficulty of installing and calibrating the coaxiality of the foldable transmission shaft system is reduced, the installation accuracy of the transmission shaft system is ensured, and the manufacturing quality of the helicopter is improved. At present, the transmission shaft coaxiality laser equipment calibration method has been applied to a certain type of helicopter.

[0032] The specific process is: the helicopter foldable transmission shaft coaxiality installation and calibration method comprises the following steps:

[0033] Step 1: pre-assemble the rigid support, the middle reducer and the peelable gasket installed under the rigid support and the middle reducer on the machine using process bolts.

[0034] Step 2: Use the two clamping rings on the foldable drive shaft tooling to clamp the axial surfaces at both ends of the foldable drive shaft on the ground. By adjusting the extended length of the bolts connecting the two clamping rings on the special tooling, the position of the clamping rings on the axial surfaces at both ends can be adjusted, thereby overcoming the elastic force of the internal spring of the foldable drive shaft, achieving compression of the foldable drive shaft, and shortening the wheelbase of the foldable drive shaft.

[0035] Step three, conduct an on-machine test on the foldable transmission shaft, adjust the protruding length of the bolts connecting the two retaining rings on the tooling, connect the foldable transmission shaft to the rigid support and the intermediate reducer with bolts, and disassemble the tooling.

[0036] Step 4: Install a set of laser transmitters and receivers on the flange end faces of the output end of the rigid support and the flange end faces of the input end of the folding transmission shaft through the adapter tooling. The laser transmitter and receiver have Bluetooth transmitter and receiver functions. Through the disk propeller, the two laser transmitters and receivers receive the motion trajectories of the two laser beams, simulate the measured axes at both ends of the folding shaft, calculate the angle and position deviation of the two axes, and generate a model. According to the deviation model and the theoretical axis fitting, calculate the thickness of the rigid support at the connection end of the folding shaft and the peelable gasket under the middle reducer, adjust the position of the rigid support and the middle reducer according to the coaxiality result, and finally achieve the coaxiality requirements of the transmission shaft system.

[0037] The method proposed by the present invention adopts an adjustment tool that can stably compress and adjust the length of the folding shaft. After the adjustment tool is connected to the folding shaft, the spring force is overcome by compression, and the length of the folding shaft is adapted to the distance of the connection ends, thereby realizing the installation of the folding shaft. The calibration method of the folding transmission shaft system of the present invention is universal, and the non-folding transmission shaft system can also be calibrated after installation by applying this method.

[0038] The above specific implementation methods or cases are only used to explain the technical solutions of the present invention, and are not intended to limit the present invention. Any parts not described in detail are regarded as conventional technical means in the art. A person of ordinary skill in the art should understand that based on the design concept of the present application, the technical solutions described in the aforementioned implementation methods should be adaptively modified, or some or all of the technical features therein should be replaced by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for installing the coaxiality of a foldable transmission shaft of a helicopter, characterized in that: The folding shaft is limited by adjusting the length of the folding shaft, and the internal spring of the folding shaft is compressed by tightening the thread to further shorten the length of the folding shaft so that it is smaller than the assembly spacing on both sides. After the folding shaft is successfully installed, the adjusting tool is gradually loosened, and the spring is gradually relaxed, so that the concave and convex toothed disc ends are meshed, and one end of the flange is butted and fastened; After the folding axis is installed, a group of laser transmitters and receivers are installed at both ends of the folding axis through the bracket; the motion trajectories of the two laser beams are received by the disk propeller and the two laser transmitters and receivers to simulate the actual axis lines at both ends of the folding axis, calculate the angle and position deviation of the two axis lines and generate a model; according to the deviation model and the theoretical axis fitting, the thickness of the adjustment gasket under the product at the connection end of the folding axis is calculated, and the installation of the folding axis is completed according to the final state.

2. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 1, characterized in that: The adjustment tool comprises a first fastener, a second fastener, and an adjusting bolt; The first fastener is tightly connected to one end of the foldable transmission shaft, and the second fastener is tightly connected to the other end of the foldable transmission shaft; the distance between the first fastener and the second fastener is adjusted by an adjusting bolt, thereby realizing the telescopic length of the foldable transmission shaft.

3. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 1, characterized in that: During installation, first pre-assemble the rigid support, the intermediate reducer and the peelable gasket installed under the rigid support and the intermediate reducer on the machine using process bolts to preliminarily fix the rigid support and the intermediate reducer.

4. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 3, characterized in that: In the ground state, use the two clamping rings on the foldable drive shaft adjustment tooling to clamp the axial surfaces at both ends of the foldable drive shaft. By adjusting the extended length of the bolts connecting the two clamping rings on the tooling, the position of the clamping rings on the axial surfaces at both ends can be adjusted, thereby overcoming the elastic force of the internal spring of the foldable drive shaft, realizing compression of the foldable drive shaft and shortening the wheelbase of the foldable drive shaft.

5. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 4, characterized in that: Carry out on-machine test on the adjusted foldable drive shaft, adjust the protruding length of the bolts connecting the two retaining rings on the tooling, connect the foldable drive shaft to the rigid support and the intermediate reducer with bolts, and disassemble the tooling.

6. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 5, characterized in that: During the on-machine test, determine whether it can be installed between the rigid support and the middle reducer; the length of the foldable drive shaft is slightly smaller than the distance between the rigid support and the middle reducer to ensure that it can be freely inserted between the rigid support and the middle reducer.

7. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 6, characterized in that: A set of laser transmitting and receiving devices are respectively installed on the flange end face of the output end of the rigid support and the flange end face of the input end of the foldable transmission shaft through the adapter tooling.

8. A method for installing the coaxiality of a foldable transmission shaft of a helicopter as claimed in claim 7, characterized in that: The adapter tooling is a laser transmitter and receiver tooling bracket, including a cardboard and a retractable adjustment shaft arranged above the cardboard. The cardboard is used for fixing the lower end, and the retractable adjustment shaft above the cardboard is connected to the laser transmitter and receiver.

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