A rigidity testing device for a flexible element

Abstract

A rigidity testing device for flexible element relates to the technical field of rigidity testing of rotary mechanical couplings. The rigidity testing device for flexible element can only complete axial or angular rigidity measurement, and the fixture of the rigidity testing device for flexible element is limited by the position and size of the installation hole of the measured part. The rigidity testing device for flexible element comprises a body frame, a base, an inner ring lower fixture, a centering device, an outer ring upper fixture, two electric cylinder mechanisms and four deformation detection units. The base is fixedly connected to the middle part of the lower end of the body frame, the inner ring lower fixture is arranged at the upper end of the base, four deformation detection units are arranged on the outer side of the inner ring lower fixture in the circumferential direction, the centering device is arranged at the middle part of the upper end of the inner ring lower fixture, the outer ring upper fixture is arranged directly above the inner ring lower fixture, the two electric cylinder mechanisms are symmetrically fixedly connected to the middle part of the upper end of the body frame, and the execution end of the electric cylinder mechanism is connected to the upper end of the outer ring upper fixture. The rigidity testing device for flexible element is used for rigidity testing of disc flexible elements.

Description

Technical Field

[0001] This invention relates to the field of stiffness testing technology for rotating machinery couplings, and more specifically to a stiffness testing device for flexible elements. Background Technology

[0002] Couplings are crucial connecting components in marine propulsion transmission systems. They not only transmit main power and torque but also compensate for axial and radial deformation of the shaft system, while possessing a certain degree of vibration and noise reduction capabilities. The overall performance of the coupling directly affects the stability and safety of the entire transmission system. The stiffness of the flexible element has a significant impact on the coupling's ability to compensate for deformation and reduce vibration and noise. Therefore, accurate measurement of the flexible element stiffness is essential for the structural design and overall performance of the coupling. Existing flexible element stiffness testing devices can only measure axial or angular stiffness, and the fixtures of these devices are limited by the position and size of the mounting holes on the tested component. Based on this, the present invention provides a stiffness testing device for flexible elements, enabling accurate measurement of the axial and angular stiffness of the flexible elements in couplings, which is of great significance for ensuring the reliability of marine propulsion transmission systems. Summary of the Invention

[0003] In order to solve the problems that existing flexible element stiffness testing devices can only measure axial or angular stiffness, and that the fixtures of flexible element stiffness testing devices are limited by the position and size of the mounting holes of the tested component, this invention proposes a stiffness testing device for flexible elements.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0005] A stiffness testing device for flexible elements includes a frame, a base, an inner lower clamp, a centerer, an outer upper clamp, two electric cylinder mechanisms, and four deformation detection units. The base is fixed to the middle of the lower end of the frame. The inner lower clamp is located at the upper end of the base. Four deformation detection units are evenly distributed along the circumferential direction on the outer side of the inner lower clamp. The centerer is located at the middle of the upper end of the inner lower clamp. The outer upper clamp is located directly above the inner lower clamp. The two electric cylinder mechanisms are symmetrically fixed to the middle of the upper end of the frame. The actuator of the electric cylinder mechanism is connected to the upper end of the outer upper clamp.

[0006] Furthermore, the fuselage frame is a gantry frame.

[0007] Furthermore, the base includes a base plate, four raised posts and four guide rods. The base plate is horizontally fixed to the middle of the lower end of the machine frame. The lower ends of the four raised posts and four guide rods are vertically and evenly distributed on the upper surface of the base plate. The upper ends of the raised posts are fixed to the lower inner ring clamp, and the upper ends of the guide rods are slidably connected to the lower inner ring clamp.

[0008] Furthermore, the deformation detection unit includes a sensor support frame, a guard plate, a limiting block, a displacement sensor, and a locking handle. The sensor support frame is horizontal and arranged radially along the inner ring lower clamp. The inner end of the sensor support frame is fixedly connected to the inner ring lower clamp. A guard plate is vertically arranged at the lower part of the outer end of the sensor support frame. A positioning groove is provided on the sensor support frame along its length. The guard plate is slidably connected along the positioning groove by a set of positioning screws. The displacement sensor is arranged on the upper part of one side of the guard plate. A limiting groove is provided vertically in the middle of one side of the guard plate. The limiting block is fitted into the limiting groove and slidably connected to the limiting groove. A locking handle is inserted into the outer end face of the limiting block. The end of the locking handle passes through the limiting groove and is threaded with a locking nut.

[0009] Furthermore, the inner ring lower clamp includes a lower clamping plate, a lower clamping platform, eight T-blocks, eight inner diameter positioning pins, a lifting hand dial, and a lifting screw. The lower clamping platform is parallel to the top of the base plate. The upper end of the shim column is fixedly connected to the lower clamping platform. The upper end of the guide rod is inserted into the lower clamping platform and slidably connected to it. The lower end of the lifting screw is perpendicularly fixed to the base plate, and the upper end of the lifting screw is inserted into the lower clamping platform. A lifting hand dial is threaded onto the lifting screw. The upper end face of the lowering dial is rotatably connected to the lower end face of the lower clamping platform. The lower clamping plate is fixedly connected to the middle of the upper end face of the lower clamping platform. Eight T-slots are evenly distributed along the circumferential direction on the upper end face of the lower clamping plate. Each T-slot is arranged in the radial direction. A T-block is inserted into the T-slot. The T-block is slidably connected to the T-slot. A fastening screw is provided on the upper end face of the T-block. The end of the fastening screw is threadedly connected to the lower clamping plate. An inner diameter positioning pin is horizontally and vertically fixed to the middle of the inner end face of the T-block.

[0010] Furthermore, the inner end of the sensor support frame is connected to the upper end face of the lower clamping platform by screws.

[0011] Furthermore, the centering device includes a disc, a central lifting rod, three support rods, three adjusting nuts, three fixed seats, three set screws, and three set seats. The lower clamping disc has a central through hole in its center, and the upper surface of the lower clamping platform has a central blind hole in its center. The disc is inserted into the central blind hole of the lower clamping platform. The central lifting rod is vertically fixed to the center of the upper surface of the disc. The three fixed seats are evenly distributed and fixed to the upper surface of the disc along the circumferential direction. Support rods are horizontally inserted into the fixed seats. The three support rods are arranged in a centrally symmetrical manner. The support rods are slidably connected to the fixed seats. A threaded rod is fixed to the inner end of the support rod. A set seat is fitted on the threaded rod. An adjusting nut is rotatably connected to the side wall of the set seat. The adjusting nut is threadedly connected to the threaded rod. The set seat is vertically fixed to the upper surface of the disc. A set screw is threadedly connected to the upper end of the set seat. The end of the set screw abuts against the outer side wall of the threaded rod.

[0012] Furthermore, the strut is positioned above the lower clamping plate.

[0013] Furthermore, a dual-specification tension / compression sensor is connected to the actuating end of the electric cylinder mechanism. The dual-specification tension / compression sensor is hinged to the upper end face of the clamp on the outer ring via a cross hinge.

[0014] Furthermore, the outer ring upper clamp includes an upper clamping plate, eight positioning screws, eight upper clamping blocks, eight lower clamping blocks, eight thickness adjusting bolts, two triangular guide frames, and two positioning pins. The upper clamping plate is arranged parallel to and directly above the lower clamping plate. Self-aligning seats are fixed to both sides of the upper end face of the upper clamping plate. One right-angled side of the triangular guide frame is slidably connected to the vertical sidewall of the machine frame along the height direction. The other right-angled side of the triangular guide frame is located on the upper end face of the upper clamping plate and inserted into the self-aligning seat. A positioning pin is horizontally inserted into one side of the self-aligning seat. A self-aligning groove is provided radially on the other right-angled side of the frame. The middle part of the positioning pin is inserted into the self-aligning groove. Both ends of the positioning pin are provided with fastening nuts, which are respectively located on both sides of the self-aligning seat. Eight screw grooves are evenly distributed circumferentially on the upper end surface of the upper clamping plate. Each screw groove is arranged radially and a positioning screw is inserted into the screw groove. The end of the positioning screw is threaded to the upper clamping block. The lower clamping block is located on the inner side below the upper clamping block. The thickness adjustment bolt is threaded to the lower clamping block and the upper clamping block respectively in the vertical direction.

[0015] The beneficial effects of this invention compared to the prior art are:

[0016] This invention proposes a stiffness testing device for flexible components. Compared with traditional flexible component stiffness testing devices, the difference is that this device can complete both axial stiffness and angular stiffness tests of flexible components in a single clamping operation. Furthermore, this invention uses a pressure plate to clamp the test piece, which is not limited by the position and size of the mounting holes on the test piece. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the lower clamp in this invention;

[0019] Figure 3 This is a schematic diagram of the structure of the disk-type flexible element 6 in this invention;

[0020] Figure 4 This is a schematic diagram of the structure of the clamp 7 on the outer ring in this invention;

[0021] Figure 5 This is a schematic diagram of the centering device 5 in this invention. Detailed Implementation

[0022] Specific implementation method one: Combining Figures 1 to 5 This embodiment describes a stiffness testing device for flexible elements, comprising a frame 1, a base 2, an inner lower clamp 4, a centerer 5, an outer upper clamp 7, two electric cylinder mechanisms 8, and four deformation detection units 3. The base 2 is fixed to the middle of the lower end of the frame 1. The inner lower clamp 4 is disposed at the upper end of the base 2. Four deformation detection units 3 are evenly distributed along the circumferential direction on the outer side of the inner lower clamp 4. The centerer 5 is disposed at the middle of the upper end of the inner lower clamp 4. The outer upper clamp 7 is disposed directly above the inner lower clamp 4. The two electric cylinder mechanisms 8 are symmetrically fixed to the middle of the upper end of the frame 1. The actuator end of the electric cylinder mechanism 8 is connected to the upper end of the outer upper clamp 7.

[0023] The deformation measurement unit 3 is used to measure the vertical deformation of the disk-type flexible element 6;

[0024] The inner ring lower clamp 4 is used to center and clamp the inner ring of the disc-type flexible element 6;

[0025] The centering device 5 is used to center the inner diameter of the disc-type flexible element 6;

[0026] The clamp 7 on the outer ring is used to clamp the outer ring of the disk-type flexible element 6;

[0027] The electric cylinder mechanism 8 is used to apply loads and can simultaneously apply tension or pressure to the clamp 7 on the outer ring. Through one clamping, the axial stiffness and angular stiffness tests of the disc-type flexible element 6 can be completed respectively.

[0028] Specific Implementation Method Two: Combining Figures 1 to 5 This embodiment describes a gantry frame 1. Other components and connection methods are the same as in specific embodiment one.

[0029] Specific implementation method three: Combining Figures 1 to 5 This embodiment describes a base 2 comprising a base plate 2-1, four elevation columns 2-2, and four guide rods 2-3. The base plate 2-1 is horizontally fixed to the middle of the lower end of the machine frame 1. The lower ends of the four elevation columns 2-2 and the four guide rods 2-3 are vertically and evenly distributed on the upper surface of the base plate 2-1. The upper ends of the elevation columns 2-2 are fixedly connected to the lower inner ring clamp 4, and the upper ends of the guide rods 2-3 are slidably connected to the lower inner ring clamp 4. Other components and connection methods are the same as in specific embodiment two.

[0030] The height of the base 2 can be changed by adjusting the configuration of the shim column 2-2;

[0031] Specific implementation method four: Combination Figures 1 to 5This embodiment describes a deformation detection unit 3 comprising a sensor support frame 3-1, a guard plate 3-2, a limiting block 3-3, a displacement sensor 3-4, and a locking handle 3-5. The sensor support frame 3-1 is horizontal and arranged radially along the inner ring lower clamp 4. The inner end of the sensor support frame 3-1 is fixedly connected to the inner ring lower clamp 4. The lower part of the outer end of the sensor support frame 3-1 is vertically provided with the guard plate 3-2. The sensor support frame 3-1 has a positioning groove along its length. The guard plate 3-2 is slidably connected along the positioning groove by a set of positioning screws. The displacement sensor 3-4 is located on the upper part of one side of the guard plate 3-2. The middle part of one side of the guard plate 3-2 has a limiting groove along the vertical direction. The limiting block 3-3 is fitted into the limiting groove and slidably connected to the limiting groove. The locking handle 3-5 is inserted into the outer end face of the limiting block 3-3. The end of the locking handle 3-5 passes through the limiting groove and is threaded with a locking nut. Other components and connection methods are the same as in Specific Implementation Method 1.

[0032] This design adjusts the position of the probe of the displacement sensor 3-4 by sliding the position of the limit block 3-3, so that it contacts the workpiece. After adjustment, the locking handle 3-5 is used to lock and position it.

[0033] Specific Implementation Method Five: Combining Figures 1 to 5 This embodiment describes an inner ring lower clamp 4 comprising a lower clamping plate 4-1, a lower clamping platform 4-2, eight T-blocks 4-3, eight inner diameter positioning pins 4-4, eight lifting hand dials 4-5, and a lifting screw 4-6. The lower clamping platform 4-2 is parallel to and directly above the base plate 2-1. The upper end of the shim column 2-2 is fixedly connected to the lower clamping platform 4-2. The upper end of the guide rod 2-3 is inserted into the lower clamping platform 4-2 and slidably connected to it. The lower end of the lifting screw 4-6 is perpendicularly fixed to the base plate 2-1, and the upper end of the lifting screw 4-6 is inserted into the lower clamping platform 4-2. -6 is threadedly connected to a lifting hand dial 4-5. The upper end face of the lifting hand dial 4-5 is rotatably connected to the lower end face of the lower clamping platform 4-2. The lower clamping plate 4-1 is fixedly connected to the middle of the upper end face of the lower clamping platform 4-2. Eight T-slots are evenly distributed along the circumferential direction on the upper end face of the lower clamping plate 4-1. Each T-slot is arranged radially. A T-block 4-3 is inserted into the T-slot and is slidably connected to the T-slot. A fastening screw is provided on the upper end face of the T-block 4-3. The end of the fastening screw is threadedly connected to the lower clamping plate 4-1. An inner diameter positioning pin 4-4 is horizontally and vertically fixed to the middle of the inner end face of the T-block 4-3. Other components and connection methods are the same as in specific embodiment four.

[0034] This design achieves the vertical height of the lower clamping platform 4-2 by rotating the lifting hand dial 4-5. After the workpiece is placed, the radial position of the T-block 4-3 is moved to make the inner diameter locating pin 4-4 press against the inner ring of the workpiece, thus achieving positioning and clamping.

[0035] Specific Implementation Method Six: Combination Figures 1 to 5 In this embodiment, the inner end of the sensor support frame 3-1 is connected to the upper end face of the lower clamping platform 4-2 by screws. Other components and connection methods are the same as in specific embodiment five.

[0036] Specific implementation method seven: Combining Figures 1 to 5 This embodiment describes a centering device 5 comprising a disc 5-1, a central lifting rod 5-2, three support rods 5-3, three adjusting nuts 5-4, three fixing seats 5-5, three set screws 5-6, and three fixing seats 5-7. The lower clamping disc 4-1 has a central through hole in its center, and the lower clamping platform 4-2 has a central blind hole in its center on its upper surface. The disc 5-1 is inserted into the central blind hole of the lower clamping platform 4-2. The central lifting rod 5-2 is vertically fixed to the center of the upper surface of the disc 5-1. The three fixing seats 5-5 are evenly distributed and fixed to the disc 5-1 along the circumferential direction. On the upper surface, a support rod 5-3 is horizontally inserted into the fixed seat 5-5. The three support rods 5-3 are arranged symmetrically at the center. The support rods 5-3 are slidably connected to the fixed seat 5-5. A threaded rod is fixed to the inner end of the support rod 5-3. A setter seat 5-7 is fitted onto the threaded rod. An adjusting nut 5-4 is rotatably connected to the side wall of the setter seat 5-7. The adjusting nut 5-4 is threadedly connected to the threaded rod. The setter seat 5-7 is vertically fixed to the upper surface of the disc 5-1. A set screw 5-6 is threadedly connected to the upper end of the setter seat 5-7. The end of the set screw 5-6 abuts against the outer side wall of the threaded rod. Other components and connection methods are the same as in specific embodiment five.

[0037] The lower end of the central lifting rod 5-2 is threaded to the middle of the disc 5-1, and the end of the central lifting rod 5-2 is screwed onto the lower clamping platform 4-2. An anti-rotation screw head 5-8 is fixed to one side of the lower end face of the disc 5-1. An anti-rotation groove is provided on one side of the middle of the lower clamping platform 4-2, and the anti-rotation screw head 5-8 is inserted into the anti-rotation groove. This design ensures that when installing the centering device 5, rotating the central lifting rod 5-2 locks it onto the lower clamping platform 4-2. The cooperation between the anti-rotation screw head 5-8 and the anti-rotation groove prevents the disc 5-1 from rotating when the centering device 5 is locked in position.

[0038] This design uses a centering device 5 to center the workpiece. After placing the disc 5-1, it is locked by the central lifting rod 5-2. Then, the three length-adjusting nuts 5-4 are adjusted so that the outer ends of the three adjusting support rods 5-3 are pressed against the side wall of the inner diameter of the workpiece's center hole, thus completing the centering of the workpiece.

[0039] Specific implementation method eight: Combination Figures 1 to 5 This embodiment describes a support rod 5-3 positioned above the lower clamping plate 4-1. Other components and connections are the same as in specific embodiment seven. This design ensures that during centering, the outer end face of the support rod 5-3 acts on the side wall of the inner diameter of the workpiece's central hole.

[0040] Specific Implementation Method Nine: Combining Figures 1 to 5 In this embodiment, the actuator of the electric cylinder mechanism 8 is connected to a dual-specification tension / compression sensor, which is hinged to the upper end face of the outer ring clamp 7 via a cross hinge. Other components and connections are the same as in specific embodiment eight.

[0041] Specific Implementation Method Ten: Combining Figures 1 to 5 This embodiment describes an outer ring upper clamp 7 comprising an upper clamping plate 7-1, eight positioning screws 7-2, eight upper clamping blocks 7-3, eight lower clamping blocks 7-4, eight thickness adjusting bolts 7-5, two triangular guide frames 7-6, and two positioning pins 7-7. The upper clamping plate 7-1 is arranged parallel to and directly above the lower clamping plate 4-1. Self-aligning seats are fixed to both sides of the upper surface of the upper clamping plate 7-1. One right-angled side of the triangular guide frame 7-6 is slidably connected to the vertical sidewall of the machine frame 1 along the height direction. The other right-angled side of the triangular guide frame 7-6 is located on the upper surface of the upper clamping plate 7-1 and inserted into the self-aligning seat. A positioning pin is horizontally inserted into one side of the self-aligning seat. Pin 7-7 and triangular guide frame 7-6 have a self-aligning groove on the other right-angled side in the radial direction. The middle part of the positioning pin 7-7 is inserted into the self-aligning groove. Both ends of the positioning pin 7-7 are provided with fastening nuts, which are respectively located on both sides of the self-aligning seat. Eight screw grooves are evenly distributed in the circumferential direction on the upper end surface of the upper clamping plate 7-1. Each screw groove is arranged in the radial direction, and a positioning screw 7-2 is inserted in the screw groove. The end of the positioning screw 7-2 is threaded to the upper clamping block 7-3. The lower clamping block 7-4 is located on the inner side below the upper clamping block 7-3. The thickness adjusting bolt 7-5 is threaded to the lower clamping block 7-4 and the upper clamping block 7-3 in the vertical direction. Other components and connection methods are the same as in specific embodiment nine.

[0042] The vertical sidewall of the fuselage frame 1 is provided with a guide groove along the height direction for guiding the triangular guide frame 7-6;

[0043] The diagonally distributed triangular guide frames 7-6 are used for the centering adjustment of the upper clamping plate 7-1. The triangular guide frames 7-6 on both sides of the upper clamping plate 7-1 are moved outward in the radial direction, and one right-angled side of the triangular guide frame 7-6 enters the guide groove in the vertical side wall of the machine frame 1. Then, the fastening nuts at both ends of the positioning pin 7-7 are tightened to center and guide the upper clamping plate 7-1 when it moves up and down.

[0044] The adjusting bolt 7-5 is used to adjust the contact surface of the lower clamping block 7-4 with the test piece.

[0045] The surfaces of the lower clamping platform 4-2, T-block 4-3, upper clamping block 7-3, and lower clamping block 7-4 that need to contact the part are all copper-plated.

[0046] The method for testing the stiffness of flexible components using the above-mentioned testing device includes the following steps:

[0047] Step 1: Clamping the test specimen

[0048] The method for clamping the specimen includes the following steps:

[0049] Step 1: First, place the clamp 7 on the outer ring of the specimen at the top of the testing device; then, loosen the fastening nut on the positioning pin 7-7, adjust the center position of the upper clamp 7-1, complete the centering adjustment, and then tighten the fastening nut; finally, adjust the relative position of the lower clamp 7-4 and the upper clamp 7-3 by adjusting the thickness bolt 7-5, so that the lower clamp 7-4 moves away in the vertical direction;

[0050] Step 2: Manually lift the disc-shaped flexible element 6 onto the lower clamping plate 4-1, adjust the center lifting rod 5-2 and the length adjusting nut 5-4 to center the inner diameter of the disc-shaped flexible element 6; adjust the position of the T-block 4-3 to center and clamp the inner diameter of the disc-shaped flexible element 6; after the inner diameter of the disc-shaped flexible element 6 is positioned and clamped, rotate the center lifting rod 5-2 in the opposite direction and lift it up to remove the centerer 5;

[0051] Step 3: Move the triangular guide frames 7-6 on both sides of the upper clamping plate 7-1 outward in the radial direction. One right-angled side of the triangular guide frame 7-6 enters the guide groove in the vertical side wall of the machine frame 1, which can center and guide the upper clamping plate 7-1 when it moves up and down. Move the two electric cylinder mechanisms 8 down synchronously, bringing the outer ring upper clamp 7 close to the upper surface of the disc-shaped flexible element 6, about 3-5mm away from the upper surface. Move the electric cylinder mechanisms 8 down slowly in sync. After the upper clamping plate 7-1 is in contact with the disc-shaped flexible element 6, the pressure sensed by the dual-specification tension and compression sensors reaches the set value and controls the electric cylinder mechanisms 8 to stop descending. Adjust the specimen positioning screws 7-2 and the thickness adjusting bolts 7-5 to complete the clamping of all clamping points on the outer diameter of the disc-shaped flexible element 6.

[0052] Step 4: Loosen and hold the locking handle 3-5 and move it upward so that the probe of the displacement sensor 3-4 contacts the deformation point of the workpiece to be measured. After moving it into place, tighten the positioning screw. The upward measurement position is positioned by the limit block 3-3, and the vertical position of the displacement sensor 3-4 is adjusted and locked by the positioning screw.

[0053] Step 2: Measurement of axial stiffness of flexible element

[0054] Two electric cylinder mechanisms 8 apply vertical tension synchronously, with the pressure gradually increasing from 0N to 4000N; dual-specification tension and compression sensors record the pressure value in real time, and displacement sensors 3-4 record the vertical displacement of the specimen in real time. The axial stiffness of the flexible element is calculated.

[0055] Step 3: Measurement of angular stiffness of flexible element

[0056] Two electric cylinder mechanisms 8 apply vertical tension and vertical pressure respectively, which gradually increase from 0N to 2000N; dual-specification tension and compression sensors record the force value in real time, and displacement sensors 3-4 record the vertical displacement of the specimen in real time. The angular stiffness of the flexible element is calculated.

[0057] A stiffness testing device for flexible components using the above-mentioned technical solution can simultaneously measure the vertical deformation of each measuring point of the disc-type flexible component and the tension or pressure applied by the electric cylinder mechanism 8, thereby accurately obtaining the stiffness of the flexible component. It can complete the axial stiffness and angular stiffness tests of the flexible component in one clamping, thereby improving the overall performance of the coupling and improving the reliability of the ship propulsion transmission system.

[0058] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A stiffness testing device for flexible elements, characterized in that: It includes a fuselage frame (1), a base (2), an inner ring lower clamp (4), a centerer (5), an outer ring upper clamp (7), two electric cylinder mechanisms (8) and four deformation detection units (3). The base (2) is fixed to the middle of the lower end of the fuselage frame (1). The inner ring lower clamp (4) is set at the upper end of the base (2). Four deformation detection units (3) are evenly distributed along the circumferential direction on the outer side of the inner ring lower clamp (4). The centerer (5) is set at the middle of the upper end of the inner ring lower clamp (4). The outer ring upper clamp (7) is set directly above the inner ring lower clamp (4). The two electric cylinder mechanisms (8) are symmetrically fixed to the middle of the upper end of the fuselage frame (1). The execution end of the electric cylinder mechanism (8) is connected to the upper end of the outer ring upper clamp (7). The outer ring upper clamp (7) includes an upper clamping plate (7-1), eight positioning screws (7-2), eight upper clamping blocks (7-3), eight lower clamping blocks (7-4), eight thickness adjusting bolts (7-5), two triangular guide frames (7-6), and two positioning pins (7-7). The upper clamping plate (7-1) is arranged parallel to the lower clamping plate (4-1) directly above it. Self-aligning seats are fixed to both sides of the upper end face of the upper clamping plate (7-1). One right-angled side of the triangular guide frame (7-6) is slidably connected to the vertical side wall of the fuselage frame (1) along the height direction. The other right-angled side of the triangular guide frame (7-6) is set on the upper end face of the upper clamping plate (7-1) and inserted into the self-aligning seat. A positioning pin (7-7) is horizontally inserted into one side of the self-aligning seat. The triangular guide frame (7-6) has a self-aligning groove on the other right-angle side in the radial direction. The middle part of the positioning pin (7-7) is inserted into the self-aligning groove. Both ends of the positioning pin (7-7) are provided with fastening nuts. The fastening nuts are respectively set on both sides of the self-aligning seat. The upper end face of the upper clamping plate (7-1) is evenly distributed with eight screw grooves in the circumferential direction. Each screw groove is set in the radial direction. The positioning screw (7-2) is inserted in the screw groove. The end of the positioning screw (7-2) is threaded to the upper clamping block (7-3). The lower clamping block (7-4) is set on the inner side below the upper clamping block (7-3). The thickness adjusting bolt (7-5) is threaded to the lower clamping block (7-4) and the upper clamping block (7-3) in the vertical direction.

2. The stiffness testing device for flexible elements according to claim 1, characterized in that: The fuselage frame (1) is a gantry frame.

3. The stiffness testing device for flexible elements according to claim 2, characterized in that: The base (2) includes a base plate (2-1), four raised columns (2-2) and four guide rods (2-3). The base plate (2-1) is horizontally fixed to the middle of the lower end of the body frame (1). The lower ends of the four raised columns (2-2) and the four guide rods (2-3) are vertically and evenly distributed on the upper surface of the base plate (2-1). The upper end of the raised column (2-2) is fixed to the lower inner ring clamp (4), and the upper end of the guide rod (2-3) is slidably connected to the lower inner ring clamp (4).

4. The stiffness testing device for flexible elements according to claim 1, characterized in that: The deformation detection unit (3) includes a sensor support frame (3-1), a baffle plate (3-2), a limiting block (3-3), a displacement sensor (3-4), and a locking handle (3-5). The sensor support frame (3-1) is horizontal and arranged radially along the inner ring lower clamp (4). The inner end of the sensor support frame (3-1) is fixedly connected to the inner ring lower clamp (4). The lower part of the outer end of the sensor support frame (3-1) is vertically provided with a baffle plate (3-2). The sensor support frame (3-1) is... A positioning groove is provided along the length direction. The guard plate (3-2) is slidably connected along the positioning groove by a set of positioning screws. The displacement sensor (3-4) is set on the upper part of one side of the guard plate (3-2). A limiting groove is provided in the middle of one side of the guard plate (3-2) along the vertical direction. The limiting block (3-3) is fitted in the limiting groove and slidably connected with the limiting groove. A locking handle (3-5) is inserted into the outer end face of the limiting block (3-3). The end of the locking handle (3-5) passes through the limiting groove and is threaded with a locking nut.

5. The stiffness testing device for flexible elements according to claim 4, characterized in that: The inner ring lower clamp (4) includes a lower clamping plate (4-1), a lower clamping platform (4-2), eight T-blocks (4-3), eight inner diameter positioning pins (4-4), a lifting hand dial (4-5), and a lifting screw (4-6). The lower clamping platform (4-2) is parallel to the base plate (2-1) directly above it. The upper end of the shim column (2-2) is fixedly connected to the lower clamping platform (4-2). The upper end of the guide rod (2-3) is inserted into the lower clamping platform (4-2) and slidably connected to it. The lower end of the lifting screw (4-6) is vertically fixed to the base plate (2-1), and the upper end of the lifting screw (4-6) is inserted into the lower clamping platform (4-2). The upper end of the lifting hand dial (4-5) is connected to the threaded upper end. The upper end face of the lifting hand dial (4-5) is rotatably connected to the lower end face of the lower clamping platform (4-2). The lower clamping plate (4-1) is fixedly connected to the middle of the upper end face of the lower clamping platform (4-2). Eight T-slots are evenly distributed along the circumferential direction on the upper end face of the lower clamping plate (4-1). Each T-slot is set in the radial direction. A T-block (4-3) is inserted into the T-slot. The T-block (4-3) is slidably connected to the T-slot. A fastening screw is provided on the upper end face of the T-block (4-3). The end of the fastening screw is threadedly connected to the lower clamping plate (4-1). An inner diameter positioning pin (4-4) is horizontally and vertically fixed to the middle of the inner end face of the T-block (4-3).

6. The stiffness testing device for flexible elements according to claim 5, characterized in that: The inner end of the sensor support frame (3-1) is connected to the upper end face of the lower clamping platform (4-2) by screws.

7. The stiffness testing device for flexible elements according to claim 5, characterized in that: The centering device (5) includes a disc (5-1), a central lifting rod (5-2), three support rods (5-3), three adjusting nuts (5-4), three fixing seats (5-5), three set screws (5-6), and three fixing seats (5-7). The lower clamping disc (4-1) has a central through hole in its center, and the upper end face of the lower clamping platform (4-2) has a central blind hole in its center. The disc (5-1) is inserted into the central blind hole of the lower clamping platform (4-2). The central lifting rod (5-2) is vertically fixed to the center of the upper end face of the disc (5-1). The three fixing seats (5-5) are evenly distributed and fixed to the upper end face of the disc (5-1) along the circumferential direction. A support rod (5-3) is horizontally inserted into the fixed seat (5-5). The three support rods (5-3) are arranged in a centrally symmetrical manner. The support rod (5-3) is slidably connected to the fixed seat (5-5). A threaded rod is fixed to the inner end of the support rod (5-3). A setter seat (5-7) is fitted on the threaded rod. An adjusting nut (5-4) is rotatably connected to the side wall of the setter seat (5-7). The adjusting nut (5-4) is threadedly connected to the threaded rod. The setter seat (5-7) is vertically fixed to the upper end face of the disc (5-1). A set screw (5-6) is threadedly connected to the upper end of the setter seat (5-7). The end of the set screw (5-6) abuts against the outer side wall of the threaded rod.

8. The stiffness testing device for flexible elements according to claim 7, characterized in that: The strut (5-3) is positioned above the lower clamp (4-1).

9. The stiffness testing device for flexible elements according to claim 1, characterized in that: The electric cylinder mechanism (8) is connected to a dual-specification tension and compression sensor at its actuation end. The dual-specification tension and compression sensor is hinged to the upper end face of the clamp (7) on the outer ring via a cross hinge.

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