Automatic tightening tool and control method for large-torque nut of an aero-engine

Abstract

The application belongs to the technical field of automatic nut tightening, and discloses an aero-engine large-torque nut automatic tightening tool and a control method, which comprises a servo tightening gun, a transmission mechanism, a shaft tensioning mechanism, a rotation-stopping mechanism and a control system. The output end of the servo tightening gun is connected with the transmission mechanism. The shaft tensioning mechanism and the rotation-stopping mechanism are arranged in the transmission mechanism. The shaft tensioning mechanism is used for tensioning and positioning the aero-engine rotor shaft. The rotation-stopping mechanism is used for stopping the rotation and resisting the torsion of the aero-engine rotor shaft. The transmission mechanism is used for rotating and tightening the large nut on the aero-engine rotor shaft. The control system is electrically connected with the servo tightening gun and is used for controlling the torque of the servo tightening gun to realize the accurate tightening of the large nut. The aero-engine large-torque nut automatic tightening tool realizes the automatic and digital tightening operation of the rotor large nut tightening position, reduces the labor intensity of workers, and significantly improves the tightening precision and consistency.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automatic nut tightening, and particularly relates to an automatic large-torque nut tightening tool for an aero-engine and a control method. BACKGROUND

[0002] Most rotor structures of domestic small and medium-sized aero-engines are designed to adopt a large-torque nut with a slot to axially lock bearings, blade discs and the like, and to prevent loosening of the slot position by means of a locking washer. According to the maximum torque range required by the engine structure, the range can be 100-7000 N.m. At present, the whole process still adopts a traditional torque wrench (or a force lever method for manual tightening), and reading is recorded by observing the torque size table by the naked eye. In the tightening process, the dial reading is generally deviated, the precision is low, reading is not accurate, and the like. The automatic collection, storage and tracing of the tightening quality data cannot be realized, and the tightening precision and quality stability and consistency are difficult to guarantee, which has a direct impact on the performance of the whole engine assembly. At present, the traditional tightening method seriously depends on the operation experience and proficiency of the assembly workers, which seriously restricts the requirements of the short delivery cycle, high reliability and safety of the contemporary aircraft manufacturing on the engine. SUMMARY

[0003] The application aims to provide an automatic large-torque nut tightening tool for an aero-engine and a control method to solve the above technical problems.

[0004] To solve the above technical problems, the specific technical scheme of the automatic large-torque nut tightening tool for an aero-engine and the control method is as follows:

[0005] An automatic large-torque nut tightening tool for an aero-engine comprises a servo tightening gun, a transmission mechanism, a shaft tensioning mechanism, a rotation-stopping mechanism and a control system. The output end of the servo tightening gun is connected to the transmission mechanism. The shaft tensioning mechanism and the rotation-stopping mechanism are arranged in the transmission mechanism. The shaft tensioning mechanism is used to tension and position the aero-engine rotor shaft. The rotation-stopping mechanism is used to stop the rotation of the aero-engine rotor shaft. The transmission mechanism is used to rotate and tighten the large nut on the aero-engine rotor shaft. The control system is electrically connected to the servo tightening gun to control the torque of the servo tightening gun and realize accurate tightening of the large nut.

[0006] Further, the aero-engine rotor shaft end face has a shaft anti-rotation slot, the rotation-stopping mechanism is connected to the shaft anti-rotation slot to stop the rotation of the aero-engine rotor shaft, the large nut has a tightening slot on the outer periphery, and the transmission mechanism is connected to the tightening slot to complete the rotation and tightening of the large nut and the aero-engine rotor shaft.

[0007] Further, the transmission mechanism comprises a shell, a driving wheel, a driven wheel, a bearing and a gear shaft, the driving wheel is coaxially fixedly connected with the output shaft of the servo tightening gun, the driven wheel is engaged with the driving wheel, the gear shaft is coaxially fixedly connected with the shaft center of the driven wheel, the bearing is sleeved on the outer wall of the gear shaft, and the shell is used for mounting the driving wheel, the driven wheel, the bearing and the gear shaft to encapsulate the transmission mechanism.

[0008] Further, the gear shaft is hollow and internally provided with a rotation stopping mechanism and an axle tensioning mechanism, the lower end of the gear shaft is provided with a protrusion matched with the tightening groove, and the protrusion of the gear shaft is matched with the tightening groove to drive the large nut to rotate.

[0009] Further, the rotation stopping mechanism comprises a rotation stopping shaft, a ball spline pair, a spline sleeve and a rotation stopping bracket, the rotation stopping bracket is fixedly installed on the shell, the rotation stopping shaft is coaxially arranged on the inner wall of the gear shaft, the lower end of the ball spline pair is fixedly connected with the upper end of the rotation stopping shaft, and the spline sleeve is arranged on the outer wall of the ball spline pair and fixedly connected with the rotation stopping bracket.

[0010] Further, the lower end of the rotation stopping shaft is provided with a rotation stopping key matched with the shaft anti-rotation groove, the ball spline pair can be telescoped in the spline sleeve, so that the rotation stopping key at the lower end of the rotation stopping shaft is aligned and matched with the shaft anti-rotation groove of the aero-engine rotor shaft, and the rotation stopping shaft realizes rotation stopping by transmitting the rotation stopping torque to the shell through the ball spline pair.

[0011] Further, the axle tensioning mechanism is arranged in the rotation stopping mechanism and comprises a tensioning shaft, a tensioning nut, a screw rod and a handle, the tensioning nut is arranged at the bottom of the rotation stopping shaft, the tensioning shaft is arranged at the lower end of the rotation stopping shaft, the tensioning nut is threadedly connected with the tensioning shaft and has a gap, the tensioning shaft is provided with balls on the outer periphery of the middle portion, the upper end of the tensioning nut is connected with the screw rod, the upper end of the screw rod is fixedly connected with the handle through the center of the ball spline pair, the handle is rotated to drive the tensioning nut to rotate, the gap between the tensioning nut and the tensioning shaft is reduced, the tensioning shaft is compressed, the balls slide outwards to extrude the inner wall of the aero-engine rotor shaft, and thus the aero-engine rotor shaft is tensioned.

[0012] The application further discloses a control method of the aero-engine large-torque nut automatic tightening tool.

[0013] Step 1: the large nut is sleeved on the aero-engine rotor shaft, and several teeth are manually tightened;

[0014] Step 2: the control system inputs a torque;

[0015] Step 3: the rotation stopping shaft of the tool is aligned with the shaft anti-rotation groove of the aero-engine rotor shaft, and the handle of the axle tensioning mechanism is manually rotated to tension the aero-engine rotor shaft;

[0016] Step 4: Start the servo tightening gun to drive the gear shaft to rotate to tighten the large nut;

[0017] Step 5: At the same time as step, the rotation stopping shaft matched with the aero-engine rotor shaft transmits the rotation stopping torque to the shell through the ball spline pair to realize rotation stopping;

[0018] Step 6: The control system controls the servo tightening gun to stop working when reaching 500 Nm;

[0019] Step 7: Rotate the handle to loosen the shaft tensioning mechanism, remove the tooling, and complete the work.

[0020] The aero-engine large torque nut automatic tightening tool and control method have the following advantages:

[0021] 1) The aero-engine large torque nut automatic tightening tool realizes automatic and digital tightening operation of the rotor large nut tightening position, reduces the labor intensity of workers, and significantly improves the tightening precision and consistency;

[0022] 2) The aero-engine large torque nut automatic tightening tool realizes automatic acquisition, analysis and storage of tightening data, has the characteristics of simple torque parameter adjustment operation, high precision and strong adaptability, etc.

[0023] 3) The device uses the tensioning mechanism positioning of the engine rotor center hole, and stops rotation and twists through the evenly distributed open slot feature at the end to realize large torque nut tightening operation. The tightening tool structure design is exquisite, the cost is low, and the operation is convenient. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structure schematic view of the aero-engine large torque nut automatic tightening tool of the application;

[0025] Figure 2 It is a schematic view of the aero-engine rotor shaft and large nut connection structure;

[0026] Figure 3 It is a sectional view of the aero-engine large torque nut automatic tightening tool of the application;

[0027] Figure 4 It is a schematic view of the aero-engine large torque nut automatic tightening tool of the application in use;

[0028] Marked description in the figure: 1, servo tightening gun; 2, transmission mechanism; 21, shell; 22, driving wheel; 23, driven wheel; 24, bearing; 25, gear shaft; 251, protrusion; 3, shaft tensioning mechanism; 31, tensioning shaft; 311, ball; 32, tensioning nut; 33, screw rod; 34, handle; 4, rotation stopping mechanism; 41, rotation stopping shaft; 411, rotation stopping key; 42, ball spline pair; 43, spline sleeve; 44, rotation stopping bracket; 5, aero-engine rotor shaft; 51, shaft anti-rotation groove; 6, large nut; 61, tightening groove. DETAILED DESCRIPTION

[0029] In order to better understand the purpose, structure and function of the present application, the present application of an aero-engine large torque nut automatic tightening tool and control method is further described in detail below in combination with the drawings.

[0030] As Figures 1-4 shown, the present application of an aero-engine large torque nut automatic tightening tool, comprising servo tightening gun 1, transmission mechanism 2, shaft tensioning mechanism 3, rotation stopping mechanism 4 and control system, servo tightening gun 1 output end connection transmission mechanism 2, shaft tensioning mechanism 3 and rotation stopping mechanism 4 are arranged in transmission mechanism 2, shaft tensioning mechanism 3 is used to tension and position aero-engine rotor shaft 5, rotation stopping mechanism 4 is used to realize the rotation stopping and torsion resistance of aero-engine rotor shaft 5, transmission mechanism 2 is used to rotate and tighten large nut 6 on aero-engine rotor shaft, control system is electrically connected with servo tightening gun 1, used to control the torque of servo tightening gun 1, realizing the accurate tightening of large nut 6.

[0031] As Figure 2 shown, aero-engine rotor shaft 5 end face has shaft anti-rotation groove 51, rotation stopping mechanism 4 is connected with shaft anti-rotation groove 51 to realize the rotation stopping of aero-engine rotor shaft 5. Large nut 6 is screwed and rotated with aero-engine rotor shaft 5, large nut 6 has tightening groove 61 on the outer periphery, transmission mechanism 2 is connected with tightening groove 61, completing the rotation tightening of large nut 6.

[0032] As Figure 3 shown, transmission mechanism 2 includes shell 21, driving wheel 22, driven wheel 23, bearing 24 and gear shaft 25, driving wheel 22 is coaxially fixedly connected with servo tightening gun 1 output shaft, driven wheel 23 is engaged with driving wheel 22, gear shaft 25 is coaxially fixedly connected with the shaft center of driven wheel 23, bearing 24 is sleeved on the outer wall of gear shaft 25, shell 21 is used to install driving wheel 22, driven wheel 23, bearing 24 and gear shaft 25, encapsulating transmission mechanism 2. Gear shaft 25 is hollow, inside provided with rotation stopping mechanism 4 and shaft tensioning mechanism 3, gear shaft 25 lower end has protrusion 251 matched with tightening groove 61, gear shaft 25 protrusion 251 is matched with tightening groove 61 in place, driving large nut 6 to rotate.

[0033] The anti-rotation mechanism 4 includes an anti-rotation shaft 41, a ball spline pair 42, a spline sleeve 43, and an anti-rotation bracket 44. The anti-rotation bracket 44 is fixedly mounted on the housing 21. The anti-rotation shaft 41 is coaxially disposed on the inner wall of the gear shaft 25. The lower end of the ball spline pair 42 is keyed and fixed to the upper end of the anti-rotation shaft 41. The spline sleeve 43 is disposed on the outer wall of the ball spline pair 42 and fixedly connected to the anti-rotation bracket 44. The lower end of the anti-rotation shaft 41 has an anti-rotation key 411 that mates with the shaft anti-rotation groove 51. The ball spline pair 42 can extend and retract within the spline sleeve 43, thereby aligning the anti-rotation key 411 at the lower end of the anti-rotation shaft 41 with the shaft anti-rotation groove 51 of the aero-engine rotor shaft 5. The anti-rotation shaft 41 transmits the anti-rotation torque to the housing 21 through the ball spline pair to achieve anti-rotation.

[0034] The shaft tensioning mechanism 3 is located within the anti-rotation mechanism 4 and includes a tensioning shaft 31, a tensioning nut 32, a screw 33, and a handle 34. The tensioning nut 32 is located at the bottom of the anti-rotation shaft 41, and the tensioning shaft 31 is located at the lower end of the anti-rotation shaft 41. The tensioning nut 32 is threadedly connected to the tensioning shaft 31 and has a gap. There are balls 311 in the middle outer circumference of the tensioning shaft 31. The upper end of the tensioning nut 32 is connected to the screw 32. The upper end of the screw 32 passes through the center of the ball spline pair 42 and is fixedly connected to the handle 33. Rotating the handle 33 causes the tensioning nut 32 to rotate, reducing the gap between the tensioning nut 32 and the tensioning shaft 31. The tensioning shaft 31 is compressed, and the balls 311 slide outward and squeeze the inner wall of the aero-engine rotor shaft 5, thereby tensioning the aero-engine rotor shaft 5.

[0035] like Figure 4 As shown, the tightening process is as follows:

[0036] Step 1: Place the large nut 6 onto the aircraft engine rotor shaft 5 and manually tighten it a few threads;

[0037] Step 2: Input torque into the control system;

[0038] Step 3: Align the anti-rotation shaft 41 of the tooling with the anti-rotation groove 51 of the aero-engine rotor shaft 5, and manually rotate the handle 34 of the shaft tensioning mechanism 3 to tension the aero-engine rotor shaft 5.

[0039] Step 4: Start the servo tightening gun 1, which in turn drives the gear shaft 25 to rotate, thereby achieving the effect of tightening the large nut 6;

[0040] Step 5: Simultaneously with step 4, the anti-rotation shaft 41, which cooperates with the rotor shaft 5 of the aircraft engine, transmits the anti-rotation torque to the outer casing 21 through the ball spline pair 42 to achieve anti-rotation.

[0041] Step 6: The control system automatically stops working when the servo tightening gun 1 reaches 500 Nm;

[0042] Step 7: Rotate handle 34 to loosen the shaft tensioning mechanism 3, remove the tooling, and complete the work.

[0043] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. An automatic tightening fixture for high-torque nuts in aero-engines, characterized in that, The system includes a servo tightening gun (1), a transmission mechanism (2), a shaft tensioning mechanism (3), an anti-rotation mechanism (4), and a control system. The output end of the servo tightening gun (1) is connected to the transmission mechanism (2). The shaft tensioning mechanism (3) and the anti-rotation mechanism (4) are located within the transmission mechanism (2). The shaft tensioning mechanism (3) is used to tension and position the aero-engine rotor shaft (5). The anti-rotation mechanism (4) is used to prevent rotation and resist torsion on the aero-engine rotor shaft (5). The transmission mechanism (2) is used to rotate and tighten the large nut (6) onto the aero-engine rotor shaft (5). The control system is electrically connected to the servo tightening gun (1) and is used to control the torque of the servo tightening gun (1) to achieve precise tightening of the large nut (6). The engine rotor shaft (5) has an anti-rotation groove (51) on its end face. The anti-rotation mechanism (4) is connected to the anti-rotation groove (51) to prevent the rotation of the aircraft engine rotor shaft (5). The large nut (6) has a tightening groove (61) on its outer periphery. The transmission mechanism (2) is connected to the tightening groove (61) to complete the rotation tightening of the large nut (6) and the aircraft engine rotor shaft (5). The transmission mechanism (2) includes a housing (21), a drive wheel (22), a driven wheel (23), a bearing (24), and a gear shaft (25). The drive wheel (22) is coaxially fixedly connected to the output shaft of the servo tightening gun (1). The driven wheel (23) meshes with the drive wheel (22). The gear shaft (25) is axially connected to the driven wheel (23). The bearing (24) is sleeved on the outer wall of the gear shaft (25) and the outer shell (21) is used to install the driving wheel (22), driven wheel (23), bearing (24) and gear shaft (25) to encapsulate the transmission mechanism (2); the gear shaft (25) is hollow and has an anti-rotation mechanism (4) and a shaft tensioning mechanism (3) inside. The lower end of the gear shaft (25) has a protrusion (251) that cooperates with the tightening groove (61). After the protrusion (251) of the gear shaft (25) is in place with the tightening groove (61), it drives the large nut (6) to rotate; the anti-rotation mechanism (4) includes an anti-rotation shaft (41), a ball spline pair (42), a spline sleeve (43), and an anti-rotation bracket (44). The anti-rotation bracket (44) is fixed. The anti-rotation shaft (41) is fixedly mounted on the outer casing (21). The anti-rotation shaft (41) is coaxially arranged on the inner wall of the gear shaft (25). The lower end of the ball spline pair (42) is keyed and fixed to the upper end of the anti-rotation shaft (41). The spline sleeve (43) is arranged on the outer wall of the ball spline pair (42) and fixedly connected to the anti-rotation bracket (44). The lower end of the anti-rotation shaft (41) has an anti-rotation key (411) that cooperates with the shaft anti-rotation groove (51). The ball spline pair (42) can extend and retract within the spline sleeve (43), thereby aligning and cooperating the anti-rotation key (411) at the lower end of the anti-rotation shaft (41) with the shaft anti-rotation groove (51) of the aero-engine rotor shaft (5). The anti-rotation shaft (41) transmits the anti-rotation torque to the outer casing (21) through the ball spline pair (42) to achieve anti-rotation.

2. The automatic tightening fixture for high-torque nuts of aero-engines according to claim 1, characterized in that, The tensioning mechanism (3) is located within the anti-rotation mechanism (4) and includes a tensioning shaft (31), a tensioning nut (32), a screw (33), and a handle (34). The tensioning nut (32) is located at the bottom of the anti-rotation shaft (41), and the tensioning shaft (31) is located at the lower end of the anti-rotation shaft (41). The tensioning nut (32) is threadedly connected to the tensioning shaft (31) and has a gap. The tensioning shaft (31) has balls (311) in the middle outer circumference. The upper end of the tightening nut (32) is connected to the screw (33). The upper end of the screw (33) passes through the center of the ball spline pair (42) and is fixedly connected to the handle (34). Rotating the handle (34) drives the tightening nut (32) to rotate, reducing the gap between the tightening nut (32) and the tightening shaft (31). The tightening shaft (31) is compressed, and the balls (311) slide outward to squeeze the inner wall of the aircraft engine rotor shaft (5), thereby tightening the aircraft engine rotor shaft (5).

3. A control method for an automatic tightening fixture for high-torque nuts in aero-engines as described in claim 1 or 2, characterized in that, Includes the following steps: Step 1: Put the large nut (6) on the aircraft engine rotor shaft (5) and manually tighten it a few threads; Step 2: Input torque into the control system; Step 3: Align the anti-rotation shaft (41) of the tooling with the anti-rotation groove (51) of the aircraft engine rotor shaft (5), and manually rotate the handle (34) of the shaft tensioning mechanism (3) to tension the aircraft engine rotor shaft (5); Step 4: Start the servo tightening gun (1) to drive the gear shaft (25) to rotate and achieve the effect of tightening the large nut (6); Step 5: Simultaneously with step 5, the anti-rotation shaft (41) that cooperates with the rotor shaft (5) of the aircraft engine transmits the anti-rotation torque to the outer casing (21) through the ball spline pair (42) to achieve anti-rotation; Step 6: The control system controls the servo tightening gun (1) to automatically stop working when it reaches Nm; Step 7: Rotate handle (34) to loosen shaft tensioning mechanism (3), remove tooling, and complete the work.

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