CN112589408A - Automatic tightening device and method for blind cavity nut of aero-engine compressor rotor - Google Patents

Abstract

The invention belongs to the field of aeroengine manufacturing, and particularly relates to an automatic tightening device and method for a blind cavity nut of an aeroengine compressor rotor, wherein the device comprises an L-shaped tightening mechanism for tightening the nut; the lifting mechanism is used for controlling the L-shaped tightening mechanism to lift; a deployment/retraction mechanism for deflecting the tightening arm of the L-shaped tightening mechanism; a circumferential rotation mechanism for rotating the L-shaped tightening mechanism, the lifting mechanism and the expanding/contracting mechanism; a support mechanism for supporting the L-shaped tightening mechanism, the lifting mechanism, the expanding/contracting mechanism and the circumferential rotating mechanism; and a nut supply mechanism for supplying the L-shaped tightening mechanism with nuts. The invention is mainly used for the assembly of the aviation turbofan engine with the small bypass ratio, the high-pressure compressor of the aviation turbofan engine has deep disc cavity, inaccessible visual field and small disc center diameter and disc space, and can realize the automation of the screwing process and nut supply and the visualization of the screwing state so as to improve the screwing efficiency and the screwing precision.

Description

Automatic tightening device and method for blind cavity nut of aero-engine compressor rotor

Technical Field

The invention belongs to the field of aircraft engine manufacturing, and particularly relates to an automatic screwing device and method for a blind cavity nut of an aircraft engine compressor rotor, which are mainly used for assembling an aircraft turbofan engine with a small bypass ratio, wherein a high-pressure compressor of the aircraft turbofan engine is deep in disk cavity, inaccessible in visual field, and small in disk center diameter and disk spacing.

Background

The disk and the disk shaft of the high-pressure compressor rotor unit of the aircraft engine with a small bypass ratio are connected by densely covered inner flange bolts. As an important component of an aircraft engine, the quality of bolt connection directly influences the overall assembly performance of the engine. However, the axial structure of the rotor is complex and compact, the assembly openness of part of the connecting parts is poor, a semi-closed blind cavity structure with narrow space and inaccessible vision is easily formed, and the operation difficulty of the nut assembly connection is large.

The assembly connection work of the nut between the high-pressure compressor disks of the present aircraft engine usually depends on the handheld nut to stretch into the disk cavity for wearing, and then an ordinary wrench is utilized for limiting force. However, the semi-closed blind cavity structure makes it difficult to manually use a wrench to enter an operation position, and further, the assembly quality is difficult to meet the process requirements. At present, 2 sets of C-shaped wrenches with drive interface angular position difference of 30 are used alternately for assembly, nut cap-recognizing success rate and tightening efficiency are low and are assembly efficiency of 3 days/person/48 nuts, manual assembly inevitably causes poor consistency of engine assembly quality, and therefore, automatic blind cavity nut tightening equipment special for a gas compressor rotor of a turbofan engine needs to be researched urgently to realize automation of a tightening process, visualization of a tightening state, improvement of tightening efficiency, improvement of tightening precision and basic consistency of engine whole quality.

At present, a semi-automatic screwing device for nuts related to an aero-engine is provided, for example, chinese patent CN108237393B discloses a semi-automatic screwing device for connecting high-pressure rotor blind cavity nuts, which mainly comprises two sections of folding gear transmission screwing arms, a torque transmission rod, a screwing position indexing device, a deflection mechanism, a supporting and positioning tool, a nut placing rod and the like. Although this tightening device is easy and simple to handle, makes things convenient for a plurality of nuts to screw up operating mode, and efficiency is higher, still exists following not enoughly: 1) although the nut placing rod exists, the whole device still needs to be taken out of the cavity and then the nut needs to be placed, and the problem that the tool and the engine are repeatedly disassembled and assembled exists; 2) the device lacks a visual module, the expansion/contraction of the tightening arm, the reaching of the next tightening position and the loading of the nut are all completed manually, the efficiency is low, the device belongs to a semi-automatic device, and the device is only suitable for an engine with a certain relation between the position of a bolt to be tightened in a blind cavity of the compressor and the position of a bolt hole of a flange plate outside the compressor; 3) the two-section expansion type structure is complex, the axial movement of the nut in the screwing process possibly has stability problems of separation from the screwing head and the like, and the accessibility of the screwing position of the device is limited when the distance between the discs is small due to the structural principle.

Disclosure of Invention

Aiming at the problems that in the existing screwing technology, the screwing process of a narrow blind cavity nut is invisible, and the screwing efficiency is low due to the lack of an automatic nut supply mechanism, the invention provides an automatic screwing device applied to the blind cavity nut of a rotor of an aero-engine compressor.

In order to achieve the aim, the invention provides an automatic nut screwing device for a blind cavity of a rotor of an aircraft engine compressor, which comprises an L-shaped screwing mechanism, a lifting mechanism, an expanding/contracting mechanism, a circumferential rotating mechanism, a supporting mechanism and a nut supplying mechanism, wherein the L-shaped screwing mechanism is connected with the lifting mechanism;

the L-shaped tightening mechanism comprises a tightening arm and a torque transmission shaft, the tightening arm is arranged above the rotor disc to be connected in parallel, and the torque transmission shaft is arranged perpendicular to the tightening arm and extends out of the compressor rotor; one end of the tightening arm is fixedly connected with the torque transmission shaft, and the other end of the tightening arm is provided with a tightening sleeve;

the lifting mechanism comprises a first linkage assembly and a cam transmission assembly, the first linkage assembly is connected with the L-shaped tightening mechanism, the cam transmission assembly is connected with the first linkage assembly, and the cam transmission assembly is configured to drive the L-shaped tightening mechanism to lift along the axial direction of the torque transmission shaft;

the expansion/contraction mechanism comprises a second linkage assembly and an expansion/contraction worm gear transmission assembly, the second linkage assembly is connected with the L-shaped tightening mechanism, the expansion/contraction worm gear transmission assembly is connected with the second linkage assembly, and the expansion/contraction worm gear transmission assembly is configured to control the tightening arm to deflect around the axis of the torque transmission shaft to an expansion position or a contraction position; when the tightening arm is in the unfolding position, the tightening sleeve is positioned right above the tail end of the bolt to be tightened of the rotor disc to be connected; when the tightening arm is in the retracted position, the tightening sleeve is positioned directly above a nut supply position of the nut supply mechanism;

the circumferential rotating mechanism comprises a circumferential rotating seat and a circumferential rotating worm and gear transmission assembly for driving the circumferential rotating seat to rotate circumferentially; the L-shaped screwing mechanism, the lifting mechanism and the unfolding/shrinking mechanism are fixedly connected with the circumferential rotating seat;

the supporting mechanism is used for installing the L-shaped screwing mechanism, the lifting mechanism, the unfolding/shrinking mechanism, the circumferential rotating mechanism and the nut supplying mechanism on the air compressor;

the nut feeding mechanism comprises a turntable, a turntable rotating assembly and a nut feeding assembly; the rotary table is arranged below the L-shaped tightening mechanism, a plurality of axial through holes are uniformly formed in the circumferential direction of the rotary table, and grooves for placing nuts to be tightened are formed in the axial through holes; the turntable rotating assembly is arranged below the turntable and is configured to control the turntable to rotate around the axis of the turntable, so that the nut to be screwed in the turntable is placed at a nut supply position; the nut feeding assembly is arranged below the rotary table and is positioned right below the nut feeding position, and is configured to feed nuts to be tightened on the rotary table at the nut feeding position into the tightening sleeve positioned right above the nut feeding position.

In some embodiments, the tightening arm may include a housing and a torque transmission assembly disposed in the housing, the torque transmission assembly includes an input gear, at least one transmission gear and an output gear which are engaged in sequence, the tightening sleeve has a gear-shaped outer wall in the middle and upper and lower end portions rotatably coupled to the housing, the input gear is fixedly coupled to the lower end portion of the torque transmission shaft, and the output gear is engaged with the gear-shaped outer wall of the tightening sleeve.

In some embodiments, the second linkage assembly may include a female swivel ball spline including, in order from outside to inside in a radial direction, a splined female, a retainer, a ball, and a hollow splined shaft; the expansion/contraction worm gear and worm transmission assembly comprises an expansion/contraction worm gear, an expansion/contraction worm and an expansion/contraction motor; the hollow spline shaft is installed in torque transmission axle periphery and lower extreme link firmly in the shell, expand/shrink worm wheel link firmly in the female periphery of spline, expand/shrink worm with expand/shrink worm wheel meshing, expand/shrink motor's output shaft with expand/shrink worm is connected.

In some embodiments, the first linkage assembly may include a top plate secured to an upper portion of the torque transmission shaft above the cam gear assembly,

the cam transmission assembly comprises a cam, a cam follower, a cam driving motor, a coding disc and a plurality of photoelectric sensing switches, wherein an output shaft of the cam driving motor is sequentially connected with the cam and the coding disc, the cam is configured to be capable of driving the cam follower to move up and down along the axial direction of the torque transmission shaft, and the cam follower is contacted with the lower surface of the top disc when moving upwards; the photoelectric inductive switches are arranged on the coding disc and are arranged at the stroke change position of the cam.

In some embodiments, the supporting mechanism may include a supporting seat, a fixed connecting seat and a protective sleeve, the supporting seat is fixedly connected to the bottom of the fixed connecting seat, and the fixed connecting seat is mounted at the opposite end of the nut mounting surface of the rotor disc to be connected of the compressor; the protective sleeve is arranged in the inner cavity of the rotor of the gas compressor, the upper part of the protective sleeve is fixedly connected with the bottom of the circumferential rotating seat, and the bottom of the protective sleeve is rotatably connected with the turntable; the circumferential rotating seat and the protective sleeve are respectively in rotating connection with the supporting seat;

the side wall of the lower end of the protective sleeve is provided with an opening for unfolding or shrinking the tightening arm, and when the tightening arm is in a shrinking position, the tightening arm is completely arranged in the protective sleeve.

In some embodiments, the turntable rotating assembly includes an indexing gear, a rotating gear, and a rotating motor; the rotating gear is fixedly connected with the turntable, the indexing gear is meshed with the rotating gear, and an output shaft of the rotating motor is connected with the indexing gear; the nut supply assembly comprises a supply gear, a supply motor and a gear screw transmission unit, wherein an output shaft of the supply motor is connected with the supply gear, and the supply gear is meshed with a gear of the gear screw transmission unit; and a screw rod of the gear screw rod transmission unit is vertically positioned right below the nut supply position.

In some embodiments, the tightening sleeve may include a 3-lobed, 4-lobed, or 6-lobed front end and a compression spring disposed therein.

In some embodiments, a visual identification module mounted below the tightening arm and disposed adjacent to the tightening sleeve may also be included.

The invention also provides an automatic fastening method for the blind cavity nut of the rotor of the aero-engine compressor by using the device, which comprises the following steps:

s1: the device is arranged on the compressor, the tightening arm is at a contraction position at the moment, and the tightening sleeve is positioned right above a nut supply position;

s2: feeding nuts to be tightened at a nut feeding position into the tightening sleeve by the nut feeding assembly, and then resetting the nut feeding assembly;

s3: controlling the tightening arm to deflect a first angle by using the expansion/contraction worm gear transmission assembly, then controlling the tightening arm to rise from an initial height to a highest height by using the cam transmission assembly, so that the bottom end of the tightening sleeve is higher than the tail end of the bolt to be tightened, and finally controlling the tightening arm to deflect a second angle to an expansion position by using the expansion/contraction worm gear transmission assembly, so that the tightening sleeve is positioned above the circumference of the bolt to be tightened, wherein the sum of the first angle and the second angle is 160-200 degrees;

s4: visually recognizing the position of the bolt to be screwed, and adjusting the screwing sleeve to be right above the tail end of the first bolt to be screwed by utilizing the circumferentially-rotating worm and gear transmission assembly;

s5: connecting a tightening gun to the top end of the torque transmission shaft, transmitting output torque of the tightening gun to the tightening sleeve, driving the nut to be tightened to be screwed by the tightening sleeve, and driving the tightening sleeve to descend at the same speed as the descending speed of the nut to be screwed by the cam transmission assembly until the nut to be screwed is screwed to be attached to a tightening surface;

s6: controlling the screwing sleeve to ascend and reset to the highest height by using the cam transmission assembly; then, the expansion/contraction worm gear transmission assembly is used for deflecting the second angle of the tightening arm, then the cam transmission assembly is used for controlling the tightening arm to descend to the initial height, and then the expansion/contraction worm gear transmission assembly is used for controlling the tightening arm to deflect the first angle to the contraction position, so that the tightening sleeve is positioned right above the nut supply position;

s7: rotating a next nut to be screwed to a nut supply position by using the turntable rotating assembly, supplying the next nut to be screwed into the screwing sleeve by using the nut supply assembly again, and then resetting the nut supply assembly;

s8: rotating the tightening sleeve to a position right above the tail end of the next bolt to be tightened by utilizing the circumferential rotation worm gear transmission assembly;

s8: repeating the steps S3 and S5-S7 to complete the screwing and attaching of all the nuts;

s9: completing the pre-tightening force loading of all the nuts;

s10: and removing the device from the compressor.

In some embodiments, an output torque calibration step and a visual recognition calibration step may be further included before the step S1.

The invention has the beneficial effects that:

1) the device is used as a full-automatic nut screwing device for connecting the high-pressure rotor blind cavity nut, a series of actions and functions of identifying the position of a bolt to be screwed, reaching the next bolt to be screwed, expanding and contracting a screwing arm, lifting the screwing arm when the nut is screwed in, screwing and screwing of the nut, applying pre-tightening force and filling the nut are completed automatically according to the screwing process, and the full-automatic nut screwing device has the characteristics of high automation degree and high screwing precision, reduces the skill requirement and labor intensity of workers, avoids errors caused by manual operation, and ensures the screwing consistency of internal nuts;

2) according to the device, after one nut is screwed, the nut can be automatically filled in the device, the device and a positioning pin and a locking assembly of an engine are only required to be disassembled for several times, the nut is externally filled in the nut supply turntable, the device does not need to be disassembled to be connected with a bolt and a nut of the engine every time in the prior art, and then the nut is externally filled, so that the working efficiency of screwing the nut is improved;

3) in the whole screwing process, the visual identification module of the device transmits the picture of the screwing sleeve to an external operation and monitoring panel in real time, monitors whether the phenomena of screwing leakage, wrong screwing and nut falling exist or not, controls the device to perform corresponding operation, correspondingly feeds back screwing information to workers in real time, realizes the whole-process visualization of blind cavity nut screwing, and overcomes the difficulties that the traditional manual screwing cannot reach the view field in the cavity of the high-pressure compressor disc and the hand-leaning touch of the screwing state is difficult to obtain;

4) the unfolding/shrinking mechanism and the circumferential rotating mechanism of the device are driven by a worm gear and worm transmission pair, so that the device has self-locking property, the current position can be maintained when the motor stops working, and the high-precision screwing assembly of the device is ensured;

5) the device does not depend on the engine with a certain relation between the position of the bolt to be screwed in the blind cavity of the compressor and the position of the bolt hole of the flange plate outside the compressor, the position of the bolt to be screwed is automatically determined through the visual identification module, the device can be used for engines of more models, and the adaptability is high;

6) the device can flexibly adjust related mechanisms and programs of the device according to the requirements of the screwing process sequence, and automatically realize nut recognition, screwing and pretightening force loading of the nut;

7) the device can design a visual, automatic, high-efficiency and high-precision special blind cavity nut tightening device according to parameters of blind cavity structures of different aero-engine compressors. Meanwhile, the design concept and the main structure of the device can also be suitable for the connection and assembly of other disc shaft structures with narrow blind cavities.

Drawings

FIG. 1 is a schematic structural diagram of an automatic fastening device for blind cavity nuts of a rotor of an aircraft engine compressor (the compressor is not shown) according to an embodiment of the invention;

FIG. 2 is an overall sectional view of the aero-engine compressor rotor blind cavity nut automatic tightening device installed on the compressor according to the embodiment of the invention;

FIG. 3 is a schematic structural view of a tightening arm in the tightening mechanism of the embodiment of the present invention;

FIG. 4 is a schematic structural diagram of a lifting mechanism according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a deployment/retraction mechanism of an embodiment of the present invention;

FIG. 6 is a schematic structural view of a circumferential rotation mechanism of an embodiment of the present invention;

FIG. 7 is a schematic structural view of a support mechanism of an embodiment of the present invention;

FIG. 8 is a schematic structural view of a nut feeding mechanism according to an embodiment of the present invention;

fig. 9 is a schematic view showing the assembly of the nut feeding mechanism structure and the protective sleeve according to the embodiment of the present invention.

In the drawings:

100-L type tightening mechanism, 110-tightening arm, 111-shell, 112-input gear, 113-primary transmission gear, 114-secondary transmission gear, 115-output gear, 120-torque transmission shaft, 130-tightening sleeve, 131-elastic ferrule, 132-compression spring, 140-tightening gun;

200-lifting mechanism, 210-cam, 220-cam follower, 230-cam driving motor, 240-coding disc, 250-photoelectric sensing switch, 260-top disc;

300-deploy/retract mechanism, 310-female rotary ball spline, 311-spline female, 312-retainer, 313-ball, 314-hollow spline shaft, 315-connecting sleeve, 320-deploy/retract worm gear, 330-deploy/retract worm, 340-deploy/retract motor;

400-circumferential rotation mechanism, 410-circumferential rotation motor, 420-circumferential rotation worm, 430-circumferential rotation worm gear; 440-circumferential rotation seat, 450-rotation base;

500-supporting mechanism, 510-supporting seat, 520-fixing connecting seat, 521-quenching cylindrical pin, 522-locking component and 530-protecting sleeve;

600-nut feeding mechanism, 601-cylinder shell, 602-middle shaft, 610-rotary table, 611-groove, 620-indexing gear, 630-rotary gear, 640-rotary motor, 650-feeding gear, 660-feeding motor, 670-lead screw, 671-lead screw seat;

700-visual recognition module, 710-LED light source, 720-miniature camera;

800-compressor, 810-9 stage rotor disk rear flange plate, 820-rotor disk to be connected.

Detailed Description

The invention is further described below with reference to the accompanying drawings and examples, it being understood that the examples described below are intended to facilitate the understanding of the invention, and are not intended to limit it in any way. In the embodiment, the rotor disc to be connected takes a 3-stage rotor disc to be connected of the compressor as an example, and the automatic nut tightening device provided by the embodiment is installed on a rear flange of a 9-stage rotor disc.

As shown in fig. 1 and 2, the automatic tightening device for the blind cavity nut of the aircraft engine compressor rotor provided by the embodiment includes an L-shaped tightening mechanism 100, a lifting mechanism 200, a spreading/contracting mechanism 300, a circumferential rotating mechanism 400, a supporting mechanism 500 and a nut supplying mechanism 600.

Referring to fig. 1 to 3, the L-type tightening mechanism 100 has an overall L-shape, and includes a short arm formed of a tightening arm 110 and a long arm formed of a torque transmission shaft 120, which are perpendicularly connected to each other, an unconnected end of the tightening arm 110 is provided with a tightening sleeve 130 having a gear-shaped outer wall, and an unconnected end of the torque transmission shaft 120 is mounted with a tightening gun 140 to control the magnitude of an input torque and a rotation angle. As shown in fig. 3, the tightening arm 110 includes a housing 111, and an input gear 112, a first-stage transmission gear 113, a second-stage transmission gear 114, and an output gear 115 disposed in the housing 111, and a tightening sleeve 130 is mounted at the foremost end of the housing 111, wherein an inner ring of the input gear 112 is fixedly coupled to a lower end of the torque transmission shaft 120, the input gear 112, the first-stage transmission gear 113, the second-stage transmission gear 114, and the output gear 115 are sequentially engaged, and the output gear 115 is engaged with a gear-shaped outer wall of the tightening sleeve 130.

The L-shaped tightening mechanism 100 of the present embodiment has a one-stage tightening arm that is suitable for an engine disc shaft narrow blind cavity structure in which the ratio of the diameter D of the bolt position distribution circle to be tightened to the diameter D of the narrowest disc center inner hole is less than 3.

It should be understood that the number of drive gears in the tightening arm 110 can be set as desired.

Preferably, the tightening sleeve 130 is a gear sleeve integrated structure, i.e., the outer portion is in the shape of a gear and the inner portion is a sleeve. Preferably, an elastic ferrule 131 and a compression spring 132 are provided inside the tightening sleeve 130 for clamping the nut to be tightened and buffering the impact load during the nut filling process, and the front end portion of the elastic ferrule 131 may be 3, 4 or 6 pieces as necessary in consideration of the abrasion of the elastic ferrule 131.

Referring to fig. 1, 2 and 4, the lifting mechanism 200 includes a cam 210, a cam follower 220, a cam driving motor 230, an encoding disc 240, a photoelectric sensing switch 250 and a top disc 260, the top disc 260 is fixedly connected to the upper portion of the torque transmission shaft 120, an output shaft of the cam driving motor 230 is coaxially connected to the cam 210 and the encoding disc 240 in turn, the cam follower 220 can be driven by the rotation of the cam 210 to move up and down, and the cam follower 220 can contact with the lower surface of the top disc 260 when moving up. In the present embodiment, 5 photoelectric sensing switches 250 are installed on the code wheel 240, and are respectively installed at the stroke change positions of the cam 210 to collect stroke change information of the cam 210.

Referring to fig. 1, 2, 5 and 6, the deployment/retraction mechanism 300 includes a female rotational ball spline 310 (also referred to as a nut rotational ball spline), a deployment/retraction worm gear 320, a deployment/retraction worm 330 and a deployment/retraction motor 340. As shown in fig. 2, the female-rotary ball spline 310 includes a spline nut 311, a retainer 312, balls 313, and a hollow spline shaft 314 in sequence from outside to inside, an expansion/contraction worm wheel 320 is fixedly connected to the outer periphery of the upper portion of the spline nut 311, an expansion/contraction worm 330 is engaged with the expansion/contraction worm wheel 320, and an output shaft of an expansion/contraction motor 340 is connected to the expansion/contraction worm 330. Torque-transfer shaft 120 is disposed within the interior cavity of hollow splined shaft 314, coaxially therewith. The upper end of the hollow spline shaft 314 is fixedly connected to the top plate 260 by screws, and the lower end is fixedly connected to the housing 111 by a connecting sleeve 315.

When the cam driving motor 230 works, the cam 210 and the encoding disk 240 are driven to rotate, and the cam 210 and the encoding disk 240 rotate synchronously; the cam 210 rotates to move the cam follower 220 up and down along the axial direction of the torque transmission shaft 120, the cam follower 220 transmits the up and down movement to the hollow spline shaft 314 by lifting up the knock-out plate 260, and the hollow spline shaft 314 is engaged with the balls 313 in the holder 312 through spline grooves on the outer surface thereof, so that it can slide up and down in the holder 312, thereby achieving the up and down movement of the tightening arm 110.

The deploy/retract motor 340, when operated, drives the deploy/retract worm 330 in a forward or reverse direction, thereby causing a forward or reverse rotation of the female ball spline 310, further deflecting the tightening arm 110 secured to the hollow spline shaft 314 about the torque transfer shaft 120 axis to a deployed position (position shown in fig. 2) or a retracted position (not shown).

Referring to fig. 2 and 6, the circumferential rotation mechanism 400 includes a circumferential rotation motor 410, a circumferential rotation worm 420, a circumferential rotation worm wheel 430, a circumferential rotation seat 440, and a rotation base 450, the circumferential rotation worm wheel 430 is fixedly connected to an upper periphery of the circumferential rotation seat 440, the expansion/contraction worm 330 is engaged with the expansion/contraction worm wheel 320, an output shaft of the circumferential rotation motor 410 is connected to the circumferential rotation worm 420, and the rotation base 450 is fixedly mounted on the circumferential rotation seat 440. In particular, the L-shaped tightening mechanism 100, the lifting mechanism 200, and the expanding/contracting mechanism 300 are all fixedly connected to the circumferential rotation seat 440. As shown in fig. 2, the expanding/contracting worm 330 and the expanding/contracting motor 340 in the expanding/contracting mechanism 300, and the cam driving motor 230, the cam 210 and the encoding disk 240 in the lifting mechanism 200 are all fixedly connected with the rotating base 450, and the female rotational ball spline 310 is directly fixedly connected with the circumferential rotating seat 440, so that the L-shaped tightening mechanism 100 is fixedly connected with the circumferential rotating seat 440.

When the circumferential rotation motor 410 operates, the circumferential rotation worm 420 is driven to rotate forward or backward, so that the circumferential rotation seat 440 is controlled to rotate forward or backward, and the three mechanisms, namely the L-shaped tightening mechanism 100, the lifting mechanism 200 and the expansion/contraction mechanism 300 which are fixedly mounted on the circumferential rotation seat 440 are controlled to rotate forward or backward.

Referring to fig. 2 and 7, the supporting mechanism 500 includes a supporting seat 510, a fastening seat 520, and a protecting sleeve 530. The supporting seat 510 is disposed at the lower portion of the circumferential rotating seat 440 and connected thereto through a ball bearing, so that the circumferential rotating seat 440 can rotate relative to the supporting seat 510. The fixed connecting seat 520 is connected with a rear flange 810 of a 9-stage rotor disc of the compressor 800 through bolts so as to mount the integral device on the compressor 800. The upper part of the protection sleeve 530 is connected to the bottom of the circumferential rotation seat 440 through a bolt and is coaxial with the circumferential rotation seat, and the outer wall of the protection sleeve is connected with the support seat 510 through a ball bearing, so that the protection sleeve can rotate together with the circumferential rotation seat 440. The outer wall of the supporting seat 510 and the inner wall of the fixed connection seat 520 are in small clearance fit, and the supporting seat 510 and the protective sleeve 530 are placed on the fixed connection seat 520, so that internal working components of the device are finally placed on the fixed connection seat 520. Preferably, the fixed connecting seat 520 is mounted on the rear flange 810 of the 9-stage rotor disk by at least 3 quenching cylindrical pins 521, and the positioning and clamping of the device are realized by at least 3 locking assemblies 522, wherein the locking assemblies 522 are mounted on the upper periphery of the fixed connecting seat 520. The protective sleeve 530 is an outer protective shell of an automatic fastening device for a blind cavity nut of an aircraft engine compressor rotor,

in particular, the protective sleeve 530 is coaxial with the disk cavity of the compressor 800, and has an outer diameter configured to match a diameter d slightly smaller than the narrowest disk core inner hole, and serves as an outer protective shell of an automatic nut tightening device for a rotor blind cavity of an aircraft engine compressor. Advantageously, openings are provided in the side walls of the lower end of the protective sleeve 530 for the tightening arms 110 to expand or contract, and when the device is mounted in place on the compressor 800, the tightening arms 110 may be extended out of the openings of the protective sleeve 530 to an expanded position or retracted to a contracted position, where the tightening arms 110 are fully disposed within the protective sleeve 530.

Referring to fig. 1, 8 and 9, the nut feeding mechanism 600 includes a cylinder housing 601, a middle shaft 602, a turntable 610, an index gear 620, a rotation gear 630, a rotation motor 640, a feeding gear 650, a feeding motor 660 and a lead screw 670. In this embodiment, the cylindrical housing 601 is connected to the bottom of the protection sleeve 530 by a bolt and is coaxial with the protection sleeve, and the outer diameter of the cylindrical housing 601 is smaller than the inner diameter of the rotor hub to be connected, so that the nut supply mechanism 600 can be installed below the tightening arm 110, wherein the rotation motor 640 and the supply motor 660 are installed on the inner wall of the cylindrical housing 601, and the lead screw 670 is installed on the inner wall of the cylindrical housing 601 through the lead screw seat 671. The middle shaft 602 is fixedly connected to the center of the bottom of the protective sleeve 530, the rotary table 610 is mounted on the middle shaft 602 through an angular contact bearing, the rotary gear 630 is fixedly connected to the bottom of the rotary table 610 through a bolt and is coaxial with the rotary table 610, the indexing gear 620 is meshed with the rotary gear 630, and an output shaft of the rotary motor 640 is connected with the indexing gear 620 through a set screw. When the rotating motor 640 works, the indexing gear 620 is driven to rotate, so that the rotary table 610 is indexed to rotate.

In particular, the rotary table 610 is uniformly provided with a plurality of axial through holes in the circumferential direction, each of the axial through holes is provided with a groove 611 for placing a nut, and when the tightening arm 110 is in the retracted position, the tightening sleeve 130 is located directly above the nut feeding position. In this embodiment, the bottom of the protection sleeve 530 is provided with a through hole corresponding to the nut supply position so that the nut to be tightened in the nut supply position can be supplied into the tightening sleeve 130 inside the protection sleeve 530. Preferably, the present embodiment uses a gear screw transmission to realize automatic feeding of nuts, specifically, the screw 670 is vertically disposed right below the nut feeding position, when the feeding motor 660 is operated, the feeding gear 650 is driven to rotate, and then the screw 670 is driven to move up and down, when the screw 670 moves up, the head of the screw 670 can extend through the through hole on the turntable 610, and the nut to be screwed at the feeding position is loaded into the screwing sleeve 130 from below. Therefore, the nut feeding mechanism 600 can perform both the function of jacking up the nut to be tightened and the function of rotating the next nut to be tightened to the nut feeding position.

Specifically, the controller receives the stroke variation information of the cam 210 and then sequentially controls the working states of the 5 motors of the device of the embodiment: a cam driving motor 230, an expansion/contraction motor 340, a circumferential rotation motor 410, a rotation motor 640, and a supply motor 660.

As shown in fig. 3, the tightening device of the present embodiment further includes a visual recognition module 700 mounted below the tightening arm 110 and adjacent to the tightening sleeve 130 for bolt positioning and visual monitoring. Preferably, the visual recognition module 700 includes an LED light source 710 for blind cavity illumination and a miniature camera 720 for image acquisition and monitoring.

In the present embodiment, the vision recognition module 700 is installed below the output gear 115, and the center line of symmetry of the vision recognition module 700 coincides with the center line of symmetry of the tightening arm 110. The LED light source 710 and the miniature camera 720 of the visual recognition module 700 are arranged up and down along the axis of the engine and coincide with the symmetrical center line of the tightening arm 110; the sum of the axial height of the rotor disks 820 to be connected and the height of the tightening arm 110 is less than the lowest disk height of the compressor blind cavity. When the vision recognition module 700 recognizes the position of the bolt to be tightened, the circumferential rotation mechanism 400 is controlled to rotate by a certain angle to center the tightening sleeve 130 and the axis of the bolt to be tightened.

The invention is further explained by providing an automatic tightening method for a blind cavity nut of an aircraft engine compressor rotor by using the automatic tightening device. The method comprises the following specific steps:

A. calibration of output torque

The tightening gun 140 outputs torque within the range of 0-100 N.m, the torque and the rotation angle output by the tightening sleeve 130 are collected by using a calibration instrument, the relation between the torque and the rotation angle output by the tightening gun 140 and the actual torque and the rotation angle output by the tightening sleeve 130 is obtained by calibration software, and the torque is intelligently and accurately output according to the corresponding relation between the torque and the rotation angle in the actual tightening work.

B. Vision recognition module calibration

The vision recognition module 700 is started, an axis marking line on the tightening sleeve 130 is recognized in the collected image information, and the position is automatically calibrated to be an image center line, namely, the axis of the tightening sleeve 130 is a reference axis of the vision module 700.

C. Device mounting

With the tightening arm 110 in the retracted position, the circumferential groove 611 of the rotating disk 610 is filled with a nut to be tightened, and the tightening sleeve 130 is filled with a nut to be tightened, or the tightening sleeve 130 is filled with a nut using the process described in step I. The device is hoisted to the position right above the compressor 800, slowly descends with the assistance of manpower until the fixed connection seat 520 is attached to the rear flange 810 of the 9-stage rotor disc, and then is fixedly connected with the compressor 800 by using the quenching cylindrical pin 521 and the locking assembly 522.

D. The tightening arm 110 is deployed

The unfolding/shrinking mechanism 300 works to control the tightening arm 110 to stop working after deflecting for 130 degrees, the lifting mechanism 200 starts working to drive the cam follower 220 to move upwards to drive the tightening arm 110 to move upwards, the lifting mechanism 200 stops working after reaching the highest height, the unfolding/shrinking mechanism 300 continues working to control the tightening arm to stop working after deflecting for 50 degrees, at the moment, the tightening arm 110 reaches the unfolding position, and the tightening sleeve 130 is positioned above the circumference of the bolt distribution circle to be tightened. In the embodiment, the tightening arm 110 is expanded/contracted twice, the structural dimensions of the compressor blind cavity and the tightening arm 110 are considered comprehensively, so as to avoid interference and collision between the compressor blind cavity and the tightening arm 110, and the lower end side wall of the protection sleeve 530 is advantageously provided with communication openings with different heights so as to match the two expansion/contraction of the tightening arm 110. Preferably, when the structure of the compressor blind cavity and the tightening arm 110 is not strict, the tightening arm can rotate 180 degrees once to complete expansion/contraction.

E. Visual recognition of the position of a bolt to be tightened

(E.1) the vision recognition module 700 starts the LED light source 710 and the miniature camera 720 to work, and the bolt recognition algorithm recognizes a bolt closest to the image central line by taking the image central line as a reference, and calculates the included angle between the bolt axis and the central line. Advantageously, the bolt recognition algorithm has machine learning capability, a large number of pictures are collected initially, the position of the bolt axis closest to the reference axis is marked manually, and a machine learning library is established for repeatedly training the bolt recognition algorithm; and then comparing the included angle between the bolt axis identified by the bolt identification algorithm and the reference axis with the actual rotating angle of the device, and continuously enriching a machine learning library by using a comparison result to improve the accuracy of the bolt identification algorithm.

(E.2) the vision recognition module 700 controls the operation of the circumferential direction rotation motor 410 according to the calculated result, and the whole device rotates by an angle.

(E.3) the vision recognition module 700 compares the collected bolt axis closest to the image center line with the coaxiality of the image center line to see whether the process coaxiality requirement is met, if not, the steps (E.2) and (E.3) are repeated until the coaxiality requirement is met, and at this time, the tightening sleeve 130 is positioned right above the first bolt to be tightened.

F. The nut is screwed up to the binding surface

The tightening gun 140 outputs torque, the torque is transmitted to the tightening sleeve 130, the nut to be tightened is driven to be screwed, in the whole tightening process, when the nut starts to be screwed, the lifting mechanism 200 works to drive the cam follower 220 to move downwards, the descending motion of the tightening arm 110 is further realized, after a certain rotation angle is output, the nut is attached to a tightening surface, and at the moment, the tightening gun 140 stops working.

G. The tightening arm 110 is reset:

(G.1) the lifting mechanism 200 is operated to drive the cam follower 220 to move upward to drive the tightening arm 110 to move upward until the tightening arm 110 is reset to the maximum height.

(G.2) the expansion/contraction motor 340 works to control the tightening arm 110 to deflect and contract by 50 degrees and then stop working, then the lifting mechanism 200 continues to work to drive the cam follower 220 to move downwards to drive the tightening arm 110 to move downwards so that the tightening arm 110 descends to the initial height and then stops working, then the expansion/contraction motor 340 continues to work to control the tightening arm 110 to deflect and contract by 130 degrees and then stop working, and at the moment, the tightening sleeve 130 is positioned right above the nut supply position.

H. The device is rotated to the next bolt position

The circumferential rotation motor 410 works, the driving device integrally rotates for a certain angle (determined according to the number of the bolts to be screwed), and when the screwing arm 110 is unfolded again, the screwing sleeve 130 is positioned right above the tail end of the next bolt to be screwed, so that visual identification and positioning are not required again.

I. And (3) filling a nut:

(I.1) when the tightening arm 110 is in the contraction position, the supply motor 660 rotates in the forward direction to drive the supply gear 650 to rotate, and further drive the jacking lead screw 670 to move upwards, so that the nut in the rotary table 610 at the supply position of the supply nut is jacked up and filled into the tightening sleeve 130 through the through hole of the protection sleeve 530, and the elastic ferrule 131 and the compression spring 132 inside the tightening sleeve 130 clamp the nut to be tightened.

(I.2) the supply motor 660 rotates in reverse, driving the supply gear 650 to rotate in reverse, which in turn drives the lead screw 670 downward back to the initial position.

(I.3) the rotating motor 640 works to drive the indexing gear 620 and further drive the rotating gear 660 to drive the rotary table 610 to rotate for a certain angle (determined according to the number of nuts on the rotary table 610), and the next nut to be screwed is right above the jacking screw 670 (namely the nut supply position) at the moment to wait for the next nut filling.

(I.4) if no nut is available for loading in the rotary table 610, the quenching cylindrical pin 521 and the locking assembly 522 are removed, the device is hoisted and removed, the nut is reloaded to the rotary table 610 and the sleeve 130 is screwed, and then the steps (A), (B), (C), (D) and (E) are repeated, so that the position of the bolt to be screwed is identified and positioned again.

J. Complete the screwing and jointing of all nuts

And (4) repeating the steps (D), (F), (G), (H) and (I) until all the nuts are screwed to the binding surface, monitoring whether the phenomena of screwing missing, wrong screwing and nut falling exist or not by the vision recognition module 700 in the whole process, and feeding back the screwing information to an operator in real time.

K. Complete the pre-tightening force loading of all the nuts

(K.1) repeating the steps (D) and (E).

(K.2) the lifting mechanism 200 works to drive the cam follower 220 to move downwards so as to drive the screwing arm 110 to move downwards, meanwhile, the screwing gun 140 works to drive the screwing sleeve 130 to rotate for a certain angle until the screwing sleeve 130 sleeves the nut to be screwed, the descending distance of the screwing arm 110 is consistent with the descending displacement when the screwing arm is screwed to the joint surface, and at the moment, the lifting mechanism 200 stops working.

(K.3) the tightening gun 140 outputs the torque required by the nut tightening process, the torque is transmitted to the tightening sleeve 130, the nut to be tightened is driven to be tightened, the displacement of the nut descending at the moment is small, the whole tightening arm 110 does not need to descend in a matched mode, and after the tightening gun 140 rotates for a certain angle, the current bolt tightening is completed.

(K.4) repeating step (G.1).

(K.5) the motor 410 is rotated in the circumferential direction, and the driving device is rotated in the whole body by a certain angle (determined by the tightening process, such as the cross method), and the tightening sleeve 130 is positioned right above the next bolt to be tightened without visual identification and positioning again.

(K.6) repeating the steps (K.2), (K.3), (K.4) and (K.5) until all the nut preload loads are completed.

L. dismounting device

And (3) dismantling the quenching cylindrical pin 521 and the locking assembly 522, and hoisting and dismantling the device under the assistance of manpower.

In the present invention, unless otherwise specifically stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally formed; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "above" and "overlying" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature "under" or "beneath" a second feature includes a first feature that is directly under and obliquely below the second feature, or simply means that the first feature is at a lesser elevation than the second feature.

In the present invention, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. An automatic nut screwing device for a blind cavity of an aircraft engine compressor rotor is characterized by comprising an L-shaped screwing mechanism (100), a lifting mechanism (200), an unfolding/shrinking mechanism (300), a circumferential rotating mechanism (400), a supporting mechanism (500) and a nut supplying mechanism (600);

the L-shaped tightening mechanism (100) comprises a tightening arm (110) and a torque transmission shaft (120), wherein the tightening arm (110) is arranged above a rotor disc to be connected in parallel, and the torque transmission shaft (120) is arranged perpendicular to the tightening arm (110) and extends out of a compressor rotor; one end of the tightening arm (110) is fixedly connected with the torque transmission shaft (120), and the other end of the tightening arm is provided with a tightening sleeve (130);

the lifting mechanism (200) comprises a first linkage component and a cam transmission component, the first linkage component is connected with the L-shaped tightening mechanism (100), the cam transmission component is connected with the first linkage component and is configured to control the L-shaped tightening mechanism (100) to lift along the axial direction of the torque transmission shaft (120);

the unfolding/folding mechanism (300) comprises a second linkage assembly and an unfolding/folding worm gear transmission assembly, wherein the second linkage assembly is connected with the L-shaped tightening mechanism (100), and the unfolding/folding worm gear transmission assembly is connected with the second linkage assembly and is configured to control the tightening arm (110) to deflect to an unfolding position or a folding position around the axis of the torque transmission shaft (120); when the tightening arm (110) is in the deployed position, the tightening sleeve (130) is located directly above the tail end of the bolt to be tightened of the rotor disc to be joined; when the tightening arm (110) is in the retracted position, the tightening sleeve (130) is located directly above a nut feeding position of the nut feeding mechanism (600);

the circumferential rotating mechanism (400) comprises a circumferential rotating seat (440) and a circumferential rotating worm and gear transmission assembly for driving the circumferential rotating seat (440) to rotate circumferentially; the L-shaped tightening mechanism (100), the lifting mechanism (200) and the unfolding/shrinking mechanism (300) are fixedly connected with the circumferential rotating seat (440);

the supporting mechanism (500) is used for installing the L-shaped tightening mechanism (100), the lifting mechanism (200), the unfolding/shrinking mechanism (300), the circumferential rotating mechanism (400) and the nut supplying mechanism (600) on the compressor (800);

the nut feeding mechanism (600) comprises a rotary table (610), a rotary table rotating assembly and a nut feeding assembly; the rotary table (610) is arranged below the L-shaped tightening mechanism (100), a plurality of axial through holes are uniformly formed in the circumferential direction, and a groove (611) for placing a nut to be tightened is formed in each axial through hole; the turntable rotating assembly is arranged below the turntable (610) and is configured to control the turntable (610) to rotate around the axis thereof, so that the nut to be tightened in the turntable (610) is placed at a nut supplying position; the nut feeding assembly is arranged below the rotary table (610) and is positioned right below a nut feeding position, and is configured to feed nuts to be tightened on the rotary table (610) at the nut feeding position into the tightening sleeve (130) positioned right above the nut feeding position.

2. The device according to claim 1, characterized in that the tightening arm (110) comprises a housing (111) and a torque transmission assembly arranged in the housing (111), the torque transmission assembly comprises an input gear (112), at least one transmission gear and an output gear (115) which are engaged in sequence, the tightening sleeve (130) is provided with a gear-shaped outer wall in the middle and is rotatably connected to the housing (111) at the upper end and the lower end, the input gear (112) is fixedly connected with the lower end of the torque transmission shaft (120), and the output gear (115) is engaged with the gear-shaped outer wall of the tightening sleeve (130).

3. The apparatus of claim 2, wherein the second linkage assembly comprises a female ball spline (310), the female ball spline (310) comprising, in order from outside to inside in a radial direction, a splined female (311), a retainer (312), a ball (313), and a hollow splined shaft (314); the expansion/contraction worm gear transmission assembly comprises an expansion/contraction worm gear (320), an expansion/contraction worm (330) and an expansion/contraction motor (340); the hollow spline shaft (314) is arranged on the periphery of the torque transmission shaft (120) and the lower end of the torque transmission shaft is fixedly connected with the shell (111), the expansion/contraction worm wheel (320) is fixedly connected with the periphery of the spline nut (311), the expansion/contraction worm (330) is meshed with the expansion/contraction worm wheel (320), and the output shaft of the expansion/contraction motor (340) is connected with the expansion/contraction worm (330).

4. The device of any of claims 1 to 3, wherein the first linkage assembly includes a top plate (260), the top plate (260) being secured to an upper portion of the torque transmission shaft (120) above the cam drive assembly,

the cam transmission assembly comprises a cam (210), a cam follower (220), a cam driving motor (230), an encoding disc (240) and a plurality of photoelectric sensing switches (250), wherein an output shaft of the cam driving motor (230) is sequentially connected with the cam (210) and the encoding disc (240), the cam (210) is configured to be capable of driving the cam follower (220) to move up and down along the axial direction of the torque transmission shaft (120), and the cam follower (220) is in contact with the lower surface of the top disc (260) when moving upwards; the photoelectric sensing switches (250) are mounted on the code disc (240) and at the stroke change position of the cam (210).

5. The device according to claim 1, characterized in that the supporting mechanism (500) comprises a supporting seat (510), a fixed connecting seat (520) and a protective sleeve (530), the supporting seat (510) is fixedly connected to the bottom of the fixed connecting seat (520), and the fixed connecting seat (520) is mounted at the opposite end of the nut mounting surface of the rotor disc to be connected of the compressor (800); the protective sleeve (530) is arranged in the inner cavity of the rotor of the air compressor (800), the upper part of the protective sleeve is fixedly connected with the bottom of the circumferential rotating seat (440), and the bottom of the protective sleeve is rotatably connected with the rotary table (610); the circumferential rotating seat (440) and the protective sleeve (530) are respectively in rotating connection with the supporting seat (510);

the side wall of the lower end of the protective sleeve (530) is provided with an opening for unfolding or folding the tightening arm (110), and when the tightening arm (110) is in a folded position, the tightening arm (110) is completely arranged in the protective sleeve (530).

6. The apparatus of claim 1, wherein the dial rotating assembly comprises an indexing gear (620), a rotating gear (630), and a rotating motor (640); the rotating gear (630) is fixedly connected with the rotating disc (610), the indexing gear (620) is meshed with the rotating gear (630), and an output shaft of the rotating motor (640) is connected with the indexing gear (620); the nut feeding assembly comprises a feeding gear (650), a feeding motor (660) and a gear screw transmission unit, wherein an output shaft of the feeding motor (660) is connected with the feeding gear (650), and the feeding gear (650) is meshed with a gear of the gear screw transmission unit; the spindle (670) of the gear-spindle drive unit is located vertically directly below the nut feed position.

7. The device according to claim 1, characterized in that the tightening sleeve (130) comprises a spring ferrule (131) and a compression spring (132) arranged inside thereof, the front end of the spring ferrule (131) being 3-lobed, 4-lobed or 6-lobed.

8. The device of claim 1, further comprising a visual identification module (700) mounted below the tightening arm (110) and disposed adjacent to the tightening sleeve (130).

9. Method for automatically tightening blind nuts for rotors of aeroengines, using a device according to any one of claims 1 to 8, characterised in that it comprises the following steps:

s1: mounting the device according to one of claims 1 to 8 on the compressor (800) with the tightening arm (110) in the retracted position and the tightening sleeve (130) directly above the nut supply position;

s2: feeding nuts to be tightened in a nut feeding position into the tightening sleeve (130) by means of the nut feeding assembly, and then resetting the nut feeding assembly;

s3: controlling the tightening arm (110) to deflect a first angle by using the expansion/contraction worm gear transmission assembly, then controlling the tightening arm (110) to ascend from an initial height to a highest height by using the cam transmission assembly, so that the bottom end of the tightening sleeve (130) is higher than the tail end of the bolt to be tightened, and finally controlling the tightening arm (110) to deflect a second angle to an expansion position by using the expansion/contraction worm gear transmission assembly, so that the tightening sleeve (130) is positioned above the circumference of a bolt distribution circle to be tightened, wherein the sum of the first angle and the second angle is 160-200 degrees;

s4: visually recognizing the position of the bolt to be screwed, and adjusting the screwing sleeve (130) to be right above the tail end of the first bolt to be screwed by utilizing the circumferential rotating worm gear transmission assembly;

s5: connecting a tightening gun (140) to the top end of the torque transmission shaft (120), wherein the output torque of the tightening gun (140) is transmitted to the tightening sleeve (130), the tightening sleeve (130) drives the nut to be tightened to be screwed, and simultaneously, the tightening sleeve (130) is driven to descend at the same speed as the descending speed of the screwing of the nut to be tightened by the cam transmission assembly until the nut to be tightened is screwed to be in fit with a tightening surface;

s6: controlling the tightening sleeve (130) to ascend and return to the highest height by using the cam transmission assembly; then deflecting the tightening arm (110) by the second angle by using the expanding/contracting worm gear assembly, controlling the tightening arm (110) to descend to an initial height by using the cam gear assembly, and controlling the tightening arm (110) to deflect by the first angle to a contracted position by using the expanding/contracting worm gear assembly, so that the tightening sleeve (130) is positioned right above a nut supply position;

s7: rotating a next nut to be tightened to a nut supply position by the turntable rotating assembly, supplying the next nut to be tightened into the tightening sleeve (130) by the nut supply assembly again, and then resetting the nut supply assembly;

s8: rotating the tightening sleeve (130) to a position right above the tail end of the next bolt to be tightened by utilizing the circumferential rotation worm gear transmission assembly;

s8: repeating the steps S3 and S5-S7 to complete the screwing and attaching of all the nuts;

s9: completing the pre-tightening force loading of all the nuts;

s10: the device is removed from the compressor (800).

10. The method of claim 9, further comprising an output torque calibration step and a visual identification calibration step prior to step S1.

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