Rotor shaft locking nut dismounting device and method

Abstract

One embodiment of the present application provides a rotor shaft locking nut dismounting device and method. The axial locking force of the locking nut is "unloaded" or "loaded" by a hollow hydraulic cylinder and each force transmission part, and the wrench torque is amplified by a large gear and a small gear and a torque multiplier, so that the dismounting and mounting of the heavy load locking nut of the helicopter rotor shaft are solved, the heavy load locking nut is not damaged and can be reused, and the helicopter rotor shaft disassembly and assembly are ensured and facilitated.

Description

Technical Field

[0001] This invention belongs to the field of helicopter rotor shaft technology, and particularly relates to a rotor shaft locking nut disassembly and assembly device and method. Background Technology

[0002] During the disassembly of the helicopter gearbox, the disassembly and installation of the heavy-duty locking nut of the rotor shaft bearing is difficult, mainly due to the following factors: 1. The axial locking force of the heavy-duty locking nut is enormous, reaching 10 tons or more, which is far from sufficient by simply relying on a torque wrench with a reduction ratio; 2. The disassembly and installation of the heavy-duty locking nut is carried out while the gearbox is in the assembly state and mounted on a special rotating table, which is not conducive to operation; 3. During the disassembly and installation of the heavy-duty locking nut, braking through the internal transmission gears of the gearbox is not allowed.

[0003] Currently, there are approximately three methods for removing lock nuts: First, using ordinary metal wrenches, torque wrenches, or torque wrenches with reduction ratios. These tools work by directly applying torque to the nut to achieve removal. However, due to the enormous locking force and the limited strength of the metal material and the arm strength available to the human hand, they are unsuitable for removing or installing nuts with such high locking forces. Second, reducing friction through methods such as lubrication and rust removal to achieve nut removal or installation. Third, destructive removal by directly cutting off the nut. None of these methods can meet the requirements for removing heavy-duty lock nuts on rotor shafts. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned problems by providing a rotor shaft locking nut disassembly and assembly device and method, which solves the problem of disassembly and installation of heavy-duty locking nuts for helicopter rotor shafts.

[0005] The technical solution of the present invention is as follows: According to the first aspect of the present invention, a rotor shaft locking nut disassembly and assembly device is provided, wherein the rotor shaft bearing locking nut to be disassembled or installed is fitted on the rotor shaft, and a protective ring is fitted on the outside of the rotor shaft bearing locking nut;

[0006] The disassembly and assembly device includes: a clamping nut assembly, a hollow hydraulic cylinder, a guide brake sleeve, a load-bearing frame assembly, a large gear, a small gear, a sleeve wrench, a sleeve wrench limiting ring, a pressure adapter sleeve, and a pressure adapter sleeve limiting ring.

[0007] The hollow hydraulic cylinder is mounted on the rotor shaft, with its bottom output end contacting and fixedly connected to the guide brake sleeve mounted on the rotor shaft via a spline engagement. Its top is secured by the clamping nut assembly. The guide brake sleeve passes through the load-bearing frame assembly and is fixedly connected to it. The large gear passes through the rotor shaft and is rotatably connected to the load-bearing frame assembly via a bearing. The top of the sleeve wrench passes through the center of the large gear and is connected to it via a spline engagement. Its bottom engages with the locking nut of the rotor shaft bearing to be disassembled. The sleeve wrench's limiting ring is positioned at the... The sleeve wrench has an annular groove on the outer spline at the top of its sleeve head, which engages with the large gear to limit the movement of the sleeve wrench. The large gear has multiple annular grooves spaced circumferentially around its center. The top end of the pressure adapter sleeve passes through these annular grooves and contacts the bottom end face of the guide brake sleeve, while its bottom end contacts the protective ring. The pressure adapter sleeve limiting ring is located in an annular groove on the outer circumferential surface of the top of the pressure adapter sleeve, and engages with the large gear to limit the movement of the pressure adapter sleeve. The pinion gear is mounted in the load-bearing frame assembly via a bearing, and meshes with the large gear to form a reduction gear pair.

[0008] In one possible embodiment, the clamping nut assembly includes: a clamping nut, which is threaded to the rotor shaft and serves to provide preload to the load-bearing frame assembly; the female thread portion is copper-plated to protect the rotor shaft threads; the end face of the clamping nut has a lifting eye threaded hole for installing a lifting eye; and a rotating rod fixed to the outer circumference of the clamping nut and symmetrically arranged radially along the clamping nut, which is threaded to the clamping nut and used for manually adjusting the preload.

[0009] In one possible embodiment, the guide brake sleeve has an annular structure with a raised edge. One end is placed inside the load-bearing frame assembly and fixedly connected by screws (GB / T70.1), while the other end is placed inside the hollow hydraulic cylinder assembly and fixedly connected by bolts (GB / T5784). An internal spline is provided in the center to transmit the pressure generated by the hollow hydraulic cylinder assembly, while providing radial positioning, anti-rotation braking, and axial guidance for the entire device.

[0010] In one possible embodiment, the load-bearing frame assembly includes: a base plate, an adapter sleeve, and a gear bracket; the base plate has a recessed stepped hole for the rotor shaft to pass through, the adapter sleeve is fitted and fixed in the recessed stepped hole, the adapter sleeve has a downwardly extending boss, and the large gear is rotatably connected to the outer circumference of the boss through a bearing; the base plate also has a small gear shaft hole for the small gear to pass through, the gear bracket is disposed below the corresponding position of the small gear shaft hole and is fixedly connected to the base plate, and the upper and lower ends of the small gear are rotatably connected to the small gear shaft hole and the gear bracket through bearings, respectively.

[0011] Preferably, it also includes a balance bar, which is fixed to the base plate for device installation and adjustment.

[0012] In one possible embodiment, the sleeve wrench has an external spline on its outer diameter that engages with the internal spline of the large gear, and a pawl on its other end face that engages with a heavy-duty locking nut for disassembling and assembling the locking nut.

[0013] In one possible embodiment, the end face of the pinion shaft is provided with an internal hexagon for mating with the torque wrench or the torque multiplier.

[0014] In one possible embodiment, the pressure adapter sleeve has an annular structure, and its end face is provided with protrusions that match the number and position of multiple annular grooves on the large gear. The arc length of each annular groove is greater than the arc length of the corresponding protrusion, which can both transmit pressure and provide rotation space for the large gear. It also includes an adjusting rod, which is arranged symmetrically in the radial direction and fixed on the outer circumference of the pressure adapter sleeve to facilitate installation and adjustment.

[0015] In one possible embodiment, the hollow hydraulic cylinder has a hollow structure, and the pressure it generates can be controlled by a matching pump station. One end is fixedly connected to the guide brake sleeve by bolts, and the other end is in contact with the clamping nut assembly to provide pressure for the "unloading" or "loading" process.

[0016] It should be noted that the hollow hydraulic cylinder is a double-acting type, capable of pressurization, depressurization, and pressure holding under the action of the pump station. When the hollow hydraulic cylinder reaches the set oil pressure, it can generate sufficient pressure to counteract the locking force of the locking nut, achieving the purpose of "unloading" or "loading". The hollow hydraulic cylinder has a limit stop at the end of its ejection stroke to prevent the piston from dislodging. The hollow hydraulic cylinder has a "curve graph showing the relationship between oil pressure and generated pressure". The hollow hydraulic cylinder has threaded mounting and lifting holes on its bottom and side.

[0017] The pump station assembly includes electrical switches, an oil pump, an oil tank, a pressure gauge, a hydraulic switch, and an adjusting valve. The upper limit of the pump station pressure is selected according to the needs of the hollow hydraulic cylinder, and it can automatically release pressure if the limit is exceeded. The electrical switch is equipped with three buttons: "pressurize," "release," and "maintain pressure." The pressure gauge reading is used to determine the pressure of the hollow hydraulic cylinder. The adjusting valve is used to adjust the output pressure of the pump station.

[0018] In one possible embodiment, it also includes a limiting sleeve and a torque multiplier, the torque multiplier being placed inside the limiting sleeve and connected to the pinion to provide torque to the pinion.

[0019] According to a second aspect of the present invention, a method for installing a rotor shaft locking nut is provided, employing the aforementioned rotor shaft locking nut disassembly and assembly device, comprising the following steps:

[0020] 1) Manually tighten the locking nut to be installed until it cannot be tightened any further, and then wrap the rotor shaft with plastic sheeting to prevent scratches;

[0021] 2) Erect the rotor shaft using a special turntable, align the inner spline of the guide brake sleeve with the outer spline on the rotor shaft, and ensure that the sleeve wrench and pressure adapter sleeve are correctly positioned in their respective working positions. If necessary, manually shake the adjusting rod and the large gear.

[0022] 3) Manually tighten the clamping nut until it is determined that the hollow hydraulic cylinder is compressed to the extreme point. At this time, the hollow hydraulic cylinder is in the "depressurization" position.

[0023] 4) Pressurize the hollow hydraulic cylinder to the pressure of the protective ring;

[0024] 5) The locking nut is tightened by driving the pinion gear to drive the socket wrench. Since the socket wrench head is limited by the pressure adapter sleeve, it can only rotate a certain angle each time. When the rotation angle reaches the upper limit, the hollow hydraulic cylinder is placed in the "pressure relief" position. Then, the pressure adapter sleeve is rotated by the adjusting rod to provide space for the socket wrench head to continue rotating. Then, the hollow hydraulic cylinder is placed in the "pressure increase" position again to continue driving the pinion gear until the driving torque reaches the torque required by the locking nut.

[0025] According to a third aspect of the present invention, a method for disassembling a rotor shaft locking nut is provided, employing the aforementioned rotor shaft locking nut disassembly and assembly device, comprising the following steps:

[0026] 1) First, wrap the rotor shaft with plastic sheeting, then use a special turntable to stand the rotor shaft upright, align the inner spline of the guide brake sleeve with the outer spline on the rotor shaft, and ensure that the sleeve wrench and pressure adapter sleeve are correctly placed in their respective working positions. If necessary, shake the adjusting rod and the large gear by hand.

[0027] 2) Manually tighten the clamping nut until it is determined that the hollow hydraulic cylinder is compressed to the extreme point, at which point the hollow hydraulic cylinder is in the "depressurization" position;

[0028] 3) Pressurize the hollow hydraulic cylinder to the pressure of the protective ring;

[0029] 4) Loosen the lock nut by driving the pinion gear to move the socket wrench. Since the socket wrench head is limited by the pressure adapter sleeve, it can only rotate a certain angle each time. When the rotation angle reaches the upper limit, the hollow hydraulic cylinder should be placed in the "pressure relief" position. Then, rotate the pressure adapter sleeve through the adjusting rod to provide space for the socket wrench head to continue rotating. Then, place the hollow hydraulic cylinder in the "pressure increase" position again and continue to drive the pinion gear until the lock nut is completely loosened. Place the hollow hydraulic cylinder in the "pressure relief" position, and the lock nut can be removed manually.

[0030] Beneficial technical effects of the present invention:

[0031] This invention provides a device and method for disassembling and assembling heavy-duty locking nuts on helicopter rotor shafts. The device uses a hollow hydraulic cylinder and various force transmission components to "unload" or "load" the axial locking force of the locking nut. At the same time, it uses large and small gears and a torque multiplier to amplify the torque of the wrench. This solves the problem of disassembling and installing heavy-duty locking nuts on helicopter rotor shafts, ensuring that the heavy-duty locking nuts are not damaged and can be reused. This provides protection and convenience for the disassembly and assembly of helicopter rotor shafts. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a rotor shaft locking nut disassembly and installation device according to an embodiment of this application;

[0033] Figure 2 This is a perspective view of a rotor shaft locking nut disassembly and installation device according to an embodiment of this application;

[0034] Figure 3 This is a schematic diagram of the clamping nut assembly structure according to an embodiment of this application;

[0035] Figure 4 This is a schematic diagram of the load-bearing frame component structure according to an embodiment of this application;

[0036] Figure 5 This is a schematic diagram of the structure of the large gear and small gear in an embodiment of this application;

[0037] Figure 6 This is a schematic diagram of the pressure transfer assembly structure according to an embodiment of this application;

[0038] Figure 7 This is a schematic diagram of the large gear structure in an embodiment of this application;

[0039] Figure 8 This is a schematic diagram of the assembly of the large gear and the pressure adapter assembly in an embodiment of this application;

[0040] In the diagram, 1-Compression nut assembly, 101-Compression nut, 102-First lifting ring, 103-Rotor; 2-Hollow hydraulic cylinder assembly; 3-Guide brake sleeve; 4-First bolt; 5-First washer; 6-Screw; 7-Bearing frame assembly, 701-Adapter sleeve, 702-Base plate, 703-Gear bracket, 704-Balance bar, 705-Second lifting ring, 706-Reinforcing rib; 8-Large gear assembly, 801-Large gear, 802-First ball bearing, 803-Sleeve wrench, 804-Sleeve wrench Limiting ring, 805-Second bolt, 806-Second washer, 807-Bearing stop; 9-Pressure adapter assembly, 901-Pressure adapter sleeve, 902-Adjusting rod, 903-Pressure adapter sleeve limiting ring; 10-Locking nut; 11-Protective ring; 12-Rotor shaft; 13-Bearing end cap; 14-Third bolt; 15-Third washer; 16-Second ball bearing; 17-Pinary gear; 18-Third ball bearing; 19-Fourth bolt; 20-Fourth washer; 21-Limiting sleeve; 22-Torque multiplier. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0042] Obviously, the accompanying drawings described below are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0043] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0044] It should be noted that "first" and "second" in the serial numbers are used for description only and do not have a special emphasis function; "10-locking nut", "11-protective ring" and "12-rotor shaft" are not components of this device and are used for description only; wherein the protective ring 11 is pressed by the locking nut 10 onto the bearing of the rotor shaft 12, and the pressing force is 10 tons.

[0045] The hollow hydraulic cylinder assembly is positioned between the clamping nut assembly and the guide brake sleeve. One end is confined to the clamping assembly, while the other end provides pressure to the guide brake sleeve. The guide brake sleeve is placed inside the load-bearing frame assembly and is fixedly connected by bolts. It is used to transmit pressure and provides radial positioning, anti-rotation braking, and axial guidance for the entire device. Both the large gear assembly and the small gear assembly are mounted on the load-bearing frame assembly, and the large gear and small gear in the two assemblies mesh with each other according to a set reduction ratio. One end of the pressure adapter sleeve passes through the large gear and contacts the guide brake sleeve, while the other end contacts the protective ring. It is used to transmit pressure.

[0046] The core working principle of the device requires the cooperation of two parts: First, the pressure generated by the hollow hydraulic cylinder assembly is transmitted to the pressure adapter sleeve through the guide sleeve. The pressure adapter sleeve then transmits the received pressure through the large gear to the protective ring locked by the locking nut. This process aims to counteract or reduce the axial locking force of the locking nut, referred to as "unloading." Conversely, if the locking nut is being installed, it can be called "loading." Second, after "unloading" or "loading" is completed, the torque is transmitted to the pinion gear through a hand-held torque wrench. The pinion gear meshes with the large gear through a certain reduction ratio, transmitting the amplified torque to the locking nut, thus enabling the locking nut to be disassembled or installed. During disassembly or installation, if the torque amplified by the large and small gear sets is still insufficient to loosen or tighten the locking nut, it can be used in conjunction with the aforementioned limit sleeve and torque multiplier.

[0047] like Figure 1 , Figure 2As shown, a rotor shaft locking nut disassembly and installation device includes a core structure comprising a clamping nut assembly 1, a hollow hydraulic cylinder assembly 2, a guide brake sleeve 3, a load-bearing frame assembly 7, a large gear assembly 8, a pressure adapter sleeve assembly 9, a small gear 17, a limiting sleeve 21, and a torque multiplier 22. The hollow hydraulic cylinder assembly 2 is positioned between the clamping nut assembly 1 and the guide brake sleeve 3, with its lower end fixedly connected to the guide brake sleeve 3 via a first bolt 4 and a first washer 5. The guide brake sleeve 3 is fixedly connected to the load-bearing frame assembly 7 via screws 6, used to transmit pressure and provide radial positioning, anti-rotation braking, and axial guidance for the entire device. The large gear assembly 8 and the small gear 17 rotate with the load-bearing frame assembly 7 via a first ball bearing 802, a second ball bearing 16, and a third ball bearing 18, respectively. The components are connected and mesh with each other according to a set reduction ratio; one end of the pressure adapter sleeve assembly 9 passes through the large gear assembly 8 and contacts the guide brake sleeve 3, and is restricted within the large gear assembly 8 by the pressure adapter sleeve limiting ring 903, while the other end contacts the protective ring 11 for transmitting pressure; the limiting sleeve 21 is fixedly connected to the load-bearing frame assembly 7 by the fourth bolt 19 and the fourth washer 20; the torque multiplier 22 is placed inside the limiting sleeve 21 and is connected to the small gear 17 interface for providing torque to the small gear.

[0048] like Figure 3 As shown, the clamping nut assembly 1 includes: a clamping nut 101, a first lifting ring 103 symmetrically arranged on the top end face of the clamping nut 101, and a rotating rod 102 symmetrically fixed radially to the outer circumferential surface of the clamping nut 101; the clamping nut 101 and the rotating rod 102 are welded and fixedly connected, and the first lifting ring 103 is threadedly connected to the clamping nut 101; wherein, the clamping nut 101 is provided with internal threads and is plated with copper of 0.03-0.05mm, and is used to connect to and protect the rotor shaft 12.

[0049] like Figure 4 As shown, the load-bearing frame assembly 7 includes: an adapter sleeve 701, a base plate 702, a gear bracket 703, a balance bar 704, a second lifting ring 705, and a reinforcing rib 706. The base plate 702 has a rotor shaft hole for the rotor shaft to pass through. The adapter sleeve 701, the gear bracket 703, and the reinforcing rib 706 are all welded to the base plate 702. The second lifting ring 705 is threadedly connected to the base plate 702. The shaft diameter and end face of the adapter sleeve 701, which connect the guide brake sleeve 3 and the large gear assembly 8, need to be welded and then further machined to ensure smooth operation of the device.

[0050] like Figure 5 , Figure 7As shown, the large gear assembly 8 includes: a large gear 801, a first ball bearing 802, a sleeve wrench 803, a sleeve wrench limiting ring 804, a second bolt 805, a second washer 806, and a bearing stop 807; the outer ring of the first ball bearing 802 mates with the large gear 801 and is fixed by the second bolt 805, the second washer 806, and the bearing stop 807, while the inner ring mates with the load-bearing frame assembly 7 and is also fixed by the second bolt 805, the second washer 806, and the bearing stop 807; the sleeve wrench 803 is connected to the inner spline of the large gear 801 via an external spline, one end of which is limited within the large gear 801 by the sleeve wrench limiting ring 804, and the other end is used to tighten or loosen the locking nut 10.

[0051] like Figure 6 , Figure 8 As shown, the pressure adapter assembly 9 includes: a pressure adapter sleeve 901, an adjusting rod 902, and a pressure adapter sleeve limiting ring 903; the adjusting rod 902 is threadedly connected to the pressure adapter sleeve 901; the pressure adapter sleeve limiting ring 903 is installed in the annular groove of the pressure adapter sleeve 901 to prevent the pressure adapter sleeve 901 from disengaging from the large gear 801.

[0052] It should be noted that the hollow hydraulic cylinder assembly 2 comprises two parts: a hollow hydraulic cylinder and a pump station assembly. The hollow hydraulic cylinder has a hollow structure and is a double-acting type, capable of pressurizing, depressurizing, and holding pressure under the action of the pump station. The maximum thrust stroke of the hollow hydraulic cylinder is 20mm, and it has a limit stop at the end point to prevent the piston from dislodging. The hollow hydraulic cylinder has a "relationship curve between oil pressure and generated pressure" (9-11 tons). The hollow hydraulic cylinder has threaded mounting and lifting holes on the bottom and side.

[0053] The pump station assembly includes electrical switches, an oil pump, an oil tank, a pressure gauge, a hydraulic switch, and an adjusting valve. The upper limit of the pump station pressure is selected according to the needs of the hollow hydraulic cylinder, and it can automatically release pressure if the limit is exceeded. The electrical switch is equipped with three buttons: "Pressure Increase," "Pressure Relief," and "Pressure Holding." The pressure gauge reading is used to determine the pressure of the hollow hydraulic cylinder. In this example, when the pressure gauge reading reaches 40 MPa, the cylinder can generate 9-10 tons of pressure. The adjusting valve is used to adjust the output pressure of the pump station.

[0054] The working principle of this invention's device is as follows: The core working principle of the device requires the cooperation of two parts: First, the 9-10 tons of pressure generated by the hollow hydraulic cylinder assembly 2 is transmitted to the pressure transfer sleeve 901 through the guide brake sleeve 3. The pressure transfer sleeve 901 then transmits the received 9-10 tons of pressure through the large gear 801 to the protective ring 11. It should be noted that the pressure generated by the hollow hydraulic cylinder assembly 2 is similar in magnitude and direction to the locking force of the locking nut 10, and both act on the protective ring 11. The purpose is to counteract the axial locking force of the locking nut 10 during disassembly, referred to as "unloading." Conversely, if the locking nut is being installed, it can be called "loading." Second, after "unloading" or "loading" is completed, a torque is applied to the small gear 17 by hand using a torque wrench. The small gear 17 meshes with the large gear 801 through a reduction ratio of 1:6.09, transmitting the amplified torque to the locking nut 10, thereby realizing the disassembly or installation of the locking nut 10.

[0055] In another scenario, since the force that a human arm can generate is approximately 300 to 500 Newtons, if the torque amplified by the large and small gear sets is still insufficient to loosen the locking nut 10 during disassembly, it can be used in conjunction with the limiting sleeve 21 and the torque multiplier 22 to complete the disassembly.

[0056] It should be noted that since the sleeve wrench 803 is enclosed by the large gear 801 and the pressure adapter sleeve 901, three evenly distributed 85° annular "windows" are provided on the large gear 801. These windows are used to avoid the pressure adapter sleeve 901. Each time, the large gear 801 is only allowed to drive the sleeve wrench 803 to rotate a maximum of 25°. It takes about 2-4 tightening or loosening actions to complete the installation or removal of the locking nut 10.

[0057] Instructions for using this device when installing the locking nut 10:

[0058] 1) Before using this device, the locking nut 10 must be manually pre-tightened until it cannot be turned, and then the rotor shaft 12 is wrapped with plastic cloth (to prevent scratches);

[0059] 2) Erect the rotor shaft 12 using a dedicated turntable, lift the device, and slowly lower it from above the rotor shaft 12. At this time, it is necessary to align the inner spline of the guide brake sleeve 3 with the outer spline on the rotor shaft 12, and ensure that the sleeve wrench 803 and the pressure adapter sleeve 901 are correctly positioned in their respective working positions. If necessary, manually shake the adjusting rod 902 and the large gear 801.

[0060] 3) Manually tighten the clamping nut 101 until the hollow hydraulic cylinder is compressed to its maximum, then loosen it by 1 / 2 turn to allow for about 1mm of extension and retraction of the hollow hydraulic cylinder. At this time, the electrical switch is in the "pressure relief" position.

[0061] 4) Place the rotor shaft 12 in a horizontal position using the turntable. Ensure that the hollow hydraulic cylinder assembly 2 and the pressure adapter sleeve 901 can work normally by "pressurizing" and "depressurizing" the hollow hydraulic cylinder. If jamming occurs, loosen the clamping nut 101 by 1 / 2 turn to 1 / 4 turn and try again.

[0062] 5) Tighten the pinion 17 or torque multiplier 22 using an appropriate torque wrench. Since the socket wrench head 803 is limited by the pressure adapter sleeve 901, it can only rotate 25° at a time. When the rotation angle reaches the upper limit, the electrical switch should be placed in the "pressure relief" position. Then, manually rotate the pressure adapter sleeve 901 through the adjusting rod 902 to provide space for the socket wrench head 803 to continue rotating. Then, place the electrical switch in the "pressure increase" position again and continue to tighten with the torque wrench until the wrench torque reaches the torque required by the locking nut 10.

[0063] Instructions for using this device when disassembling the locking nut 10:

[0064] 1) Before using this device, the rotor shaft 12 must be wrapped with plastic sheeting (to prevent scratches). Then, the rotor shaft 12 is erected using a special turntable, and the device is lifted and slowly lowered from above the rotor shaft 12. At this time, the inner spline of the guide brake sleeve 3 in the device needs to be aligned with the outer spline on the rotor shaft 12, and the sleeve wrench 803 and pressure adapter sleeve 901 need to be correctly positioned in their respective working positions. If necessary, the adjusting rod 902 and the large gear 801 need to be manually shaken.

[0065] 2) Manually tighten the clamping nut 101 until the hollow hydraulic cylinder is compressed to its maximum, then loosen it by 1 / 2 turn to allow for about 1mm of extension and retraction of the hollow hydraulic cylinder. At this time, the electrical switch is in the "pressure relief" position.

[0066] 3) Place the rotor shaft 12 in a horizontal position using the turntable. Ensure that the hollow hydraulic cylinder assembly 2 and the pressure adapter sleeve 901 can work normally by "pressurizing" and "depressurizing" the hollow hydraulic cylinder. If jamming occurs, loosen the clamping nut 101 by 1 / 2 turn to 1 / 4 turn and try again.

[0067] 4) Use an appropriate torque wrench to loosen the pinion 17 or torque multiplier 22. Since the socket wrench head 803 is limited by the pressure adapter sleeve 901, it can only rotate 25° at a time. When the rotation angle reaches the upper limit, the electrical switch should be placed in the "pressure relief" position. Then, manually rotate the pressure adapter sleeve 901 through the adjusting rod 902 to provide space for the socket wrench head 803 to continue rotating. Then, place the electrical switch in the "pressure increase" position again and continue to loosen it with the torque wrench. Once it is determined that the locking nut 10 is completely loose, the electrical switch can be placed in the "pressure relief" position. Then, the entire device can be disassembled, and the locking nut 10 can be removed manually.

[0068] This invention application enables the disassembly and installation of the rotor shaft locking nut while the helicopter gearbox is in the assembly state, ensuring that the locking nut is not damaged and can be reused, thus providing protection and convenience for the disassembly and assembly of the helicopter rotor shaft.

Claims

1. A device for disassembling and assembling a rotor shaft locking nut, characterized in that, The rotor shaft bearing locking nut to be disassembled or installed is fitted onto the rotor shaft, and a protective ring is fitted around the rotor shaft bearing locking nut. The disassembly and assembly device includes: a clamping nut assembly, a hollow hydraulic cylinder assembly, a guide brake sleeve, a load-bearing frame assembly, a large gear, a small gear, a sleeve wrench, a sleeve wrench limiting ring, a pressure adapter sleeve, and a pressure adapter sleeve limiting ring. The hollow hydraulic cylinder assembly is fitted onto the rotor shaft, and the bottom output end of the hollow hydraulic cylinder assembly contacts and is fixedly connected to the guide brake sleeve fitted onto the rotor shaft via a spline fit. The top of the hollow hydraulic cylinder assembly is clamped and fixed by the clamping nut assembly. The guide brake sleeve passes through the load-bearing frame assembly and is fixedly connected to the load-bearing frame assembly. The large gear passes through the rotor shaft and is rotatably connected to the load-bearing frame assembly via a bearing. The top of the sleeve wrench passes through... The sleeve wrench is connected to the large gear via a spline through the center of the large gear. The bottom of the sleeve wrench engages with the locking nut of the rotor shaft bearing to be disassembled. A limiting ring for the sleeve wrench is located in an annular groove on the outer spline at the top of the sleeve wrench, engaging with the large gear to limit the movement of the sleeve wrench. The large gear has multiple annular grooves spaced circumferentially around its center. The top of the pressure adapter sleeve passes through these annular grooves and contacts the bottom end face of the guide brake sleeve. The bottom end of the pressure adapter sleeve contacts the protective ring. A limiting ring for the pressure adapter sleeve is located in an annular groove on the outer circumferential surface at the top of the pressure adapter sleeve, engaging with the large gear to limit the movement of the pressure adapter sleeve. The small gear is mounted within the load-bearing frame assembly via a bearing, and meshes with the large gear to form a reduction gear pair. The hollow hydraulic cylinder assembly comprises two parts: a hollow hydraulic cylinder and a pump station assembly. The pressure adapter sleeve has an annular structure, with protrusions on its end face matching the number and position of multiple annular grooves on the large gear. The arc length of each annular groove is greater than the arc length of the corresponding protrusion, which can both transmit pressure and provide rotation space for the large gear. It also includes an adjusting rod, which is arranged symmetrically in the radial direction and fixed on the outer circumference of the pressure adapter sleeve to facilitate installation and adjustment.

2. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, The guide brake sleeve has an annular structure with a raised edge. One end is placed inside the load-bearing frame assembly and is fixedly connected by screws. The other end is placed inside the hollow hydraulic cylinder assembly and is also fixedly connected by bolts. An internal spline is provided in the center.

3. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, The load-bearing frame assembly includes: a base plate, an adapter sleeve, and a gear bracket; the base plate has a recessed step hole for the rotor shaft to pass through, the adapter sleeve is fitted and fixed in the recessed step hole, the adapter sleeve has a downwardly extending boss, and the large gear is rotatably connected to the outer circumference of the boss through a bearing; the base plate also has a small gear shaft hole for the small gear to pass through, the gear bracket is set below the corresponding position of the small gear shaft hole and is fixedly connected to the base plate, and the upper and lower ends of the small gear are rotatably connected to the small gear shaft hole and the gear bracket through bearings, respectively.

4. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, The clamping nut assembly includes: a clamping nut, which is connected to the rotor shaft via threads and is used to provide preload for the load-bearing frame assembly; a lifting eye threaded hole is provided on the end face of the clamping nut for installing a lifting eye; and a rotating rod fixed on the outer circumference of the clamping nut and symmetrically arranged radially along the clamping nut, which is connected to the clamping nut via threads and is used to manually adjust the preload.

5. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, The pinion has an internal hexagonal shape on its gear shaft end face for use with a torque wrench or torque multiplier.

6. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, The sleeve wrench has an external spline on its outer diameter that mates with the internal spline of the large gear, and a pawl on its other end face that mates with the lock nut for assembling and disassembling the lock nut.

7. The rotor shaft locking nut disassembly and assembly device according to claim 1, characterized in that, It also includes a limit sleeve and a torque multiplier. The torque multiplier is placed inside the limit sleeve and connected to the pinion to provide torque to the pinion.

8. A method for installing a rotor shaft locking nut, using a rotor shaft locking nut disassembly and assembly device according to any one of claims 1-7, comprising the following steps: 1) manually pre-tightening the locking nut to be installed until it cannot be tightened further; 2) manually tightening the clamping nut until it is determined that the hollow hydraulic cylinder is compressed to its extreme point, at which point the hollow hydraulic cylinder is in the "depressurization" position; 3) "pressurizing" the pressure generated by the hollow hydraulic cylinder assembly onto the protective ring; 4) tightening the locking nut by driving the pinion gear to drive the sleeve wrench head, since the sleeve wrench head is limited by the pressure adapter sleeve, it can only rotate a certain angle each time; when the rotation angle reaches the upper limit, the hollow hydraulic cylinder is placed in the "depressurization" position, and then the pressure adapter sleeve is rotated by the adjusting rod to provide space for the sleeve wrench head to continue rotating; then the hollow hydraulic cylinder is placed in the "pressurization" position again, and the pinion gear is driven until the driving torque reaches the torque required by the locking nut.

9. A method for disassembling a rotor shaft locking nut, using a rotor shaft locking nut disassembly and assembly device according to any one of claims 1-7, comprising the following steps: 1) manually tightening the clamping nut until the hollow hydraulic cylinder is compressed to its maximum point, at which point the hollow hydraulic cylinder is in the "depressurization" position; 2) applying the pressure generated by the hollow hydraulic cylinder assembly to the protective ring; 3) loosening the locking nut by driving the pinion gear to drive the sleeve wrench. Since the sleeve wrench is limited by the pressure adapter sleeve, it can only rotate a certain angle each time; when the rotation angle reaches the upper limit, the hollow hydraulic cylinder should be placed in the "depressurization" position, and then the pressure adapter sleeve should be rotated by the adjusting rod to provide space for the sleeve wrench to continue rotating; then the hollow hydraulic cylinder should be placed in the "pressurization" position again, and the pinion gear should be driven until the locking nut is completely loosened, and the hollow hydraulic cylinder should be placed in the "depressurization" position, and the locking nut can be disassembled manually.

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