Coupling torsional rigidity testing device

Abstract

The utility model discloses a coupler torsional rigidity testing device, which belongs to the technical field of coupler production, and comprises a base, a transmission shaft, a transmission arm, a mounting seat, a first hydraulic cylinder, a first pressure sensor, a mounting bracket, a second hydraulic cylinder, a second pressure sensor, an angular displacement sensor and a controller, the installation base is installed on the base, the middle of the transverse transmission arm is connected with the transmission shaft, the length direction of the transmission arm is perpendicular to the length direction of the transmission shaft, the angular displacement sensor is installed on the installation base, and the first pressure sensor is installed on a push rod of the first hydraulic cylinder and located below one end of the transmission arm. The second pressure sensor is installed below the push rod of the second hydraulic cylinder and located above the other end of the transmission arm. The test platform provided by the utility model can realize high-precision torsional rigidity measurement of the coupler, and is simple and convenient to operate and high in measurement precision.

Description

Technical Field

[0001] The utility model belongs to the technical field of coupling production, and specifically relates to a coupling torsional stiffness testing device, in particular to a coupling torsional stiffness testing apparatus. Background Art

[0002] The coupling is used to transmit the rotational power of one shaft to another shaft, thus realizing the rotation transmission function between the two shafts. Figure 1 As shown, the coupling includes a first connecting sleeve 1 and a second connecting sleeve 2 connected to each other. When in use, the first connecting sleeve 1 and the second connecting sleeve 2 are connected to two rotating shafts respectively to achieve rotational transmission between the two rotating shafts.

[0003] In order to reliably detect the mechanical properties of the coupling, it is necessary to test the torsional stiffness of the coupling. The torsional stiffness is the ratio of the applied torsional torque to the torsional angle. The torsional torque here is the torsional torque between the first connecting sleeve 1 and the second connecting sleeve 2, and the torsional angle is the torsional angle between the first connecting sleeve 1 and the second connecting sleeve 2.

[0004] refer to Figure 1 The simplest traditional testing method is to first mark straight line segments on the outer wall surface of the first connecting sleeve 1 and the outer wall surface of the first connecting sleeve 2 respectively, and then use a torque wrench to apply torque to the coupling. Under the action of the torque, the first connecting sleeve 1 and the second connecting sleeve 2 of the coupling rotate a certain angle, causing relative movement between the two straight line segments. Then, by using a vernier caliper to detect the distance between the two straight line segments, the torsional angle is calculated, and then the torsional stiffness value of the coupling is calculated based on the torque value and torsional angle of the torque wrench. This method has the following defects: because the line has a width, when using a vernier caliper for detection, the error in the line width will be substituted into the test result. At the same time, there are operational errors that vary from person to person, making the test result unreliable; when the vernier caliper detects the distance between the lines, the torque wrench needs to be manually maintained with the torque, which makes the test operation inconvenient.

[0005] To address the above-mentioned issues, some patent documents disclose testing equipment using sensors. For example, the utility model patent with patent number "ZL 201510106451.8" discloses a method for dynamically measuring the torsional stiffness and torsional damping of a coupling, comprising an industrial computer, a PID controller, a hydraulic station, and a measuring device; the measuring device comprises a mounting base, an angle encoder, a hydraulic servo rotary cylinder, a coupling to be tested, a torque sensor, and a fixed support. This utility model has the following drawbacks: the two ends of the coupling to be tested are connected to the hydraulic servo rotary cylinder and the torque sensor, respectively. This structure cannot accurately detect the torque of the coupling to be tested because the torque sensor directly detects the torque at one end of the coupling to be tested, while the torque applied by the hydraulic servo rotary cylinder is applied to the other end of the coupling to be tested. The torque detected by the torque sensor is not the torque directly applied to the coupling to be tested, but the torque transmitted by the coupling to be tested. The transmission torque of the coupling to be tested is itself the parameter to be measured. Therefore, this utility model cannot obtain the accurate torque parameter applied to the coupling to be tested, and thus cannot accurately measure the torsional stiffness of the coupling to be tested. Utility Model Content

[0006] The purpose of the utility model is to provide a coupling torsional stiffness testing device with high measurement accuracy in order to solve the above problems.

[0007] The utility model achieves the above-mentioned purpose through the following technical solutions:

[0008] A coupling torsional stiffness testing device comprises a base, a transmission shaft, a transmission arm, a mounting base, a first hydraulic cylinder, a first pressure sensor, a mounting bracket, a second hydraulic cylinder, a second pressure sensor and an angular displacement sensor, wherein the mounting base is mounted on the base, a vertical first mounting plate and a vertical second mounting plate are provided on the mounting base, the horizontal transmission shaft is rotatably mounted on the first mounting plate, the middle portion of the horizontal transmission arm is connected to the transmission shaft, the length direction of the transmission arm is perpendicular to the length direction of the transmission shaft, the angular displacement sensor is mounted on the mounting base, one end of the transmission shaft is close to the second mounting plate for mounting the coupling to be tested, and the other end is connected to the rotating shaft of the angular displacement sensor, the vertical first hydraulic cylinder is mounted on the base, the first pressure sensor is mounted on the push rod of the first hydraulic cylinder and is located below one end of the transmission arm, the mounting bracket is mounted on the base, the vertical second hydraulic cylinder is mounted on the mounting bracket, and the second pressure sensor is mounted below the push rod of the second hydraulic cylinder and is located above the other end of the transmission arm.

[0009] In order to better realize the present invention, the present invention also includes a controller. The distance between the contact point of the transmission arm and the first pressure sensor and the center line of the transmission shaft is set to L1, and the distance between the contact point of the transmission arm and the second pressure sensor and the center line of the transmission shaft is set to L2. L1 and L2 are equal. The signal output end of the first pressure sensor, the signal output end of the second pressure sensor, and the signal output end of the angular displacement sensor are respectively connected to the signal input end of the controller, and the control input end of the first hydraulic cylinder and the control input end of the second hydraulic cylinder are respectively connected to the control output end of the controller.

[0010] Preferably, in order to enable relative movement between the first mounting plate and the second mounting plate to facilitate the installation of the coupling to be tested, the mounting seat includes a first mounting seat and a second mounting seat respectively mounted on the base, the first mounting plate is arranged on the first mounting seat, the angular displacement sensor is mounted on the first mounting seat, and the second mounting plate is arranged on the second mounting seat.

[0011] Preferably, in order to ensure that the transmission arm remains sufficiently stable while driving the transmission shaft to rotate, there are two first mounting plates and both are parallel to the second mounting plate. The transmission shaft passes through the corresponding through holes of the two first mounting plates and is connected by bearings respectively. The transmission arm is located between the two first mounting plates.

[0012] Preferably, in order to facilitate the connection between the transmission arm and the transmission shaft and avoid relative movement between the two, a transverse central through hole is provided in the middle of the transmission arm and the transmission shaft passes through the central through hole, and a tightening sleeve is installed between the transmission shaft and the wall of the central through hole of the transmission arm.

[0013] Preferably, in order to facilitate connection of the coupling to be tested with the transmission shaft, a connecting flange for connection to the coupling to be tested is provided on one end of the transmission shaft close to the second mounting plate.

[0014] Preferably, in order to facilitate the rapid movement and positioning functions between related components to facilitate assembly and installation of the coupling to be tested, the top of the base is flat and is provided with a plurality of mutually parallel inverted "T"-shaped mounting grooves, and the mounting seat and the mounting bracket are respectively connected to the corresponding inverted "T"-shaped connecting pieces in the inverted "T"-shaped mounting grooves.

[0015] Preferably, in order to reliably connect the transmission shaft and the angular displacement sensor, a connecting column is provided on one end of the transmission shaft close to the angular displacement sensor, and the connecting column is connected to the rotating shaft of the angular displacement sensor via a rigid connector.

[0016] The beneficial effects of the present invention are:

[0017] The utility model is designed with a transmission shaft, a transmission arm, a first hydraulic cylinder, a first pressure sensor, a second hydraulic cylinder, a second pressure sensor, an angular displacement sensor and a controller that are interconnected. When in use, the rotational force of the transmission arm can be directly applied to the coupling to be measured through the transmission shaft, thereby realizing accurate torsional torque detection. The rotation angle of the coupling is directly detected through the transmission shaft and the angular displacement sensor, thereby realizing accurate rotation angle detection, and ultimately realizing high-precision torsional stiffness measurement of the coupling, basically avoiding human operation errors, and the operation is simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is the main view of the coupling;

[0019] Figure 2 It is a three-dimensional diagram of the coupling torsional stiffness testing device of the utility model;

[0020] Figure 3 This is a front view of the coupling torsional stiffness testing device of the present invention;

[0021] Figure 4 It is an AA sectional view in the main view of the coupling torsional stiffness testing device of the present invention.

[0022] In the figure, 1-first connecting sleeve, 2-second connecting sleeve, 3-base, 4-inverted "T" shaped mounting groove, 5-first mounting seat, 6-angular displacement sensor, 7-first pressure sensor, 8-first hydraulic cylinder, 9-transmission arm, 10-mounting bracket, 11-second hydraulic cylinder, 12-first pressure sensor, 13-first mounting plate, 14-transmission shaft, 15-connecting flange, 16-second mounting plate, 17-second mounting seat, 18-inverted "T" shaped connector, 19-rigid connector, 20-expansion sleeve, 21-bearing. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] Example 1

[0025] like Figure 2-Figure 4As shown, the coupling torsional stiffness testing device of the present invention includes a base 3, a transmission shaft 14, a transmission arm 9, a mounting base, a first hydraulic cylinder 8, a first pressure sensor 7, a mounting bracket 10, a second hydraulic cylinder 11, a second pressure sensor 12 and an angular displacement sensor 6. The mounting base is mounted on the base 3, and a vertical first mounting plate 13 and a vertical second mounting plate 16 are provided on the mounting base. The horizontal transmission shaft 14 is rotatably mounted on the first mounting plate 13. The middle part of the horizontal transmission arm 9 is connected to the transmission shaft 14, and the length direction of the transmission arm 9 is parallel to the length direction of the transmission shaft 14. Perpendicular to each other, the angular displacement sensor 6 is mounted on the mounting base. One end of the transmission shaft 14 is close to the second mounting plate 16 for mounting the coupling to be tested, and the other end is connected to the rotating shaft of the angular displacement sensor 6. The vertical first hydraulic cylinder 8 is mounted on the top of the base. The first pressure sensor 7 is mounted on the push rod of the first hydraulic cylinder 8 and is located below one end of the transmission arm 9. The mounting bracket 10 is mounted on the top of the base. The vertical first hydraulic cylinder 11 is mounted on the mounting bracket 10. The second pressure sensor 12 is mounted below the push rod of the second hydraulic cylinder 11 and is located above the other end of the transmission arm 9. The first hydraulic cylinder 8 and the second hydraulic cylinder 11 respectively output corresponding hydraulic pressures. The first pressure sensor 7 and the second pressure sensor 12 respectively monitor the pressures and output them externally. The angular displacement sensor 6 monitors the angular displacement data and outputs them externally.

[0026] Example 2

[0027] like Figure 2-Figure 4As shown, the coupling torsional stiffness testing device of the present invention includes a base 3, a transmission shaft 14, a transmission arm 9, a mounting base, a first hydraulic cylinder 8, a first pressure sensor 7, a mounting bracket 10, a second hydraulic cylinder 11, a second pressure sensor 12, an angular displacement sensor 6 and a controller (not shown in the figure). The mounting base is installed on the base 3, and a vertical first mounting plate 13 and a vertical second mounting plate 16 are provided on the mounting base. The horizontal transmission shaft 14 is rotatably mounted on the first mounting plate 13, and the middle part of the horizontal transmission arm 9 is connected to the transmission shaft 14. The length direction of the transmission arm 9 is aligned with the length of the transmission shaft 14. The length directions are perpendicular to each other. The angular displacement sensor 6 is installed on the mounting base. One end of the transmission shaft 14 is close to the second mounting plate 16 for mounting the coupling to be tested, and the other end is connected to the rotating shaft of the angular displacement sensor 6. The vertical first hydraulic cylinder 8 is installed on the top of the base. The first pressure sensor 7 is installed on the push rod of the first hydraulic cylinder 8 and is located below one end of the transmission arm 9. The mounting bracket 10 is installed on the top of the base. The vertical second hydraulic cylinder 11 is installed on the mounting bracket 10. The second pressure sensor 12 is installed below the push rod of the second hydraulic cylinder 11 and is located above the other end of the transmission arm 9. Assume that the distance between the contact point between the transmission arm 9 and the first pressure sensor 7 and the centerline of the transmission shaft 14 is L1, and the distance between the contact point between the transmission arm 9 and the second pressure sensor 12 and the centerline of the transmission shaft 14 is L2, with L1 and L2 being equal. The signal output terminals of the first pressure sensor 7, the second pressure sensor 12, and the angular displacement sensor 6 are respectively connected to the signal input terminals of the controller, and the control input terminals of the first hydraulic cylinder 8 and the second hydraulic cylinder 11 are respectively connected to the control output terminals of the controller. The above-mentioned controller is a conventional controller (used to input hydraulic pressure data of the first hydraulic cylinder 8 and the second hydraulic cylinder 11, and simultaneously receive data acquisition feedback from the first pressure sensor 7, the second pressure sensor 12, and the angular displacement sensor 6), and is installed in conventional equipment such as an electronic control component or a control cabinet.

[0028] like Figure 2-Figure 4 As shown, the present invention also discloses the following multiple more optimized specific structures:

[0029] In order to enable relative movement between the first mounting plate 13 and the second mounting plate 16 to facilitate the installation of the coupling to be tested, the mounting seat includes a first mounting seat 5 and a second mounting seat 17 respectively mounted on the base 3, the first mounting plate 13 is arranged on the first mounting seat 5, the angular displacement sensor 6 is installed on the first mounting seat 5, and the second mounting plate 16 is arranged on the second mounting seat 17.

[0030] In order to ensure that the transmission arm 9 remains sufficiently stable while driving the transmission shaft 14 to rotate, there are two first mounting plates 13 and both are parallel to the second mounting plate 16. The transmission shaft 14 passes through the corresponding through holes of the two first mounting plates 13 and is connected respectively by bearings 21. The transmission arm 9 is located between the two first mounting plates 13.

[0031] In order to facilitate the connection between the transmission arm 9 and the transmission shaft 14 and avoid relative movement between the two, a transverse central through hole is provided in the middle of the transmission arm 9 and the transmission shaft 14 passes through the central through hole, and a tightening sleeve 20 is installed between the transmission shaft 14 and the wall of the central through hole of the transmission arm 9.

[0032] In order to facilitate the connection between the coupling to be tested and the transmission shaft 14 , a connection flange 15 for connecting to the coupling to be tested is provided on one end of the transmission shaft 14 close to the second mounting plate 16 .

[0033] In order to facilitate the rapid movement and positioning functions between related components to facilitate assembly and installation of the coupling to be tested, the top of the base 3 is flat and is provided with a plurality of mutually parallel inverted "T"-shaped mounting grooves 4. The mounting seat and the mounting bracket 10 are respectively connected to the inverted "T"-shaped connectors 18 in the corresponding inverted "T"-shaped mounting grooves 4. The inverted "T"-shaped connectors 18 can be bolts, nuts, etc., depending on needs.

[0034] In order to reliably connect the transmission shaft 14 and the angular displacement sensor 6 , a connecting column is provided on one end of the transmission shaft 14 close to the angular displacement sensor 6 . The connecting column is connected to the rotating shaft of the angular displacement sensor 6 via a rigid connector 19 .

[0035] Combine Figures 1-4 The testing method of the coupling torsional stiffness testing device of this embodiment includes the following steps:

[0036] Step A: Connect the first connecting sleeve 1 of the coupling to be tested to the connecting flange 15 of the transmission shaft 14 through bolts, and connect the second connecting sleeve 2 of the coupling to be tested to the second mounting plate 16 through bolts. During the connection process, the distance between the first mounting seat 5 and the second mounting seat 17 can be adjusted a little further to facilitate placing the coupling to be tested between the connecting flange 15 and the second mounting plate 16. After connecting the first connecting sleeve 1 or the second connecting sleeve 2, adjust the distance between the first mounting seat 5 and the second mounting seat 17 a little closer. After connecting the first connecting sleeve 1 and the second connecting sleeve 2, the first mounting base 5 and the second mounting base 17 are locked to complete the installation of the coupling to be tested; the first hydraulic cylinder 8 and the second hydraulic cylinder 11 are connected to the same hydraulic station through a tee pipe, so as to ensure that the first hydraulic cylinder 8 and the second hydraulic cylinder 11 generate the same thrust when they are in action; by adjusting the mounting nuts of the two hydraulic cylinders or other conventional methods, the two ends of the transmission arm 9 are respectively in zero-distance contact with the first pressure sensor 7 and the second pressure sensor 12, and by adjusting the zero or other conventional methods, the first pressure sensor 7, the second pressure sensor 12 and the angular displacement sensor 6 are all in zero position.

[0037] Step B: The controller activates the first hydraulic cylinder 8 and the second hydraulic cylinder 11 to synchronously extend their push rods. The thrust is transmitted to both ends of the transmission arm 9 via the first pressure sensor 7 and the second pressure sensor 12, respectively. The transmission arm 9 rotates synchronously with the transmission shaft 14. During this process, the first pressure sensor 7, the second pressure sensor 12, and the angular displacement sensor 6 transmit detection signals to the controller. The controller observes and can control the first and second hydraulic cylinders 8 and 11 to stop their movements.

[0038] Step C: After the output data of the first pressure sensor 7, the second pressure sensor 12 and the angular displacement sensor 6 are stable, the controller detects that the pressure value corresponding to the output data signal of the first pressure sensor 7 is the same as the pressure value corresponding to the output data signal of the second pressure sensor 12 and both are set to F1, and the rotation angle corresponding to the output data signal of the angular displacement sensor 6 is Φ1.

[0039] Then the utility model can calculate the torsional stiffness G1 of the first test according to the following formula:

[0040] G1=2×F1×L / Φ1,

[0041] Wherein, L is the length of the lever arm at both ends of the transmission arm 9, L=L1=L2, and the unit of G1 is Nm / °;

[0042] Example 3

[0043] Combine Figure 1-Figure 4 The testing method of the coupling torsional stiffness testing device of the second embodiment includes the following steps:

[0044] Step 1. Connect the first connecting sleeve 1 of the coupling to be tested to the connecting flange 15 of the transmission shaft 14 through bolts, and connect the second connecting sleeve 2 of the coupling to be tested to the second mounting plate 16 through bolts. During the connection process, the distance between the first mounting seat 5 and the second mounting seat 17 can be adjusted a little further to facilitate placing the coupling to be tested between the connecting flange 15 and the second mounting plate 16. After connecting the first connecting sleeve 1 or the second connecting sleeve 2, adjust the distance between the first mounting seat 5 and the second mounting seat 17 a little closer. After connecting the first connecting sleeve 1 and the second connecting sleeve 2, after locking the first mounting base 5 and the second mounting base 17, the installation of the coupling to be tested is completed; the first hydraulic cylinder 8 and the second hydraulic cylinder 11 are connected to the same hydraulic station through a tee pipe, so as to ensure that the first hydraulic cylinder 8 and the second hydraulic cylinder 11 generate the same thrust when they are in action; by adjusting the mounting nuts of the two hydraulic cylinders or other conventional methods, the two ends of the transmission arm 9 are respectively in zero-distance contact with the first pressure sensor 7 and the second pressure sensor 12, and by zeroing or other conventional methods, the first pressure sensor 7, the second pressure sensor 12 and the angular displacement sensor 6 are all in zero position;

[0045] Step 2: According to the specific test conditions and test requirements, preset the number of tests to n and the corresponding rotation angle Φ for each test i , i is a natural number between 1-n, all Φ i are all different and are all smaller than the maximum rotation angle that can be tolerated between the first connecting sleeve 1 and the second connecting sleeve 2 of the coupling to be tested;

[0046] Step 3: The controller controls and starts the first hydraulic cylinder 8 and the second hydraulic cylinder 11 to synchronously extend the push rods. The thrust is transmitted to both ends of the transmission arm 9 through the first pressure sensor 7 and the second pressure sensor 12 respectively. The transmission arm 9 rotates synchronously with the transmission shaft 14. During this process, the first pressure sensor 7, the second pressure sensor 12 and the angular displacement sensor 6 respectively transmit detection data to the controller. When the controller detects that the rotation angle corresponding to the output data signal of the angular displacement sensor 6 is the minimum angle among all Φi, it then stops the first hydraulic cylinder 8 and the second hydraulic cylinder 11.

[0047] Step 4: After the output data of the first pressure sensor 7, the second pressure sensor 12, and the angular displacement sensor 6 stabilize, the controller detects that the pressure value corresponding to the output data of the first pressure sensor 7 is the same as the pressure value corresponding to the output data of the second pressure sensor 12 and both are set to F1. The rotation angle corresponding to the output data of the angular displacement sensor 6 is Φ1. The torsional stiffness G1 of the first test is calculated according to the following formula:

[0048] G1=2×F1×L / Φ1,

[0049] Wherein, L is the length of the lever arm at both ends of the transmission arm 9, L=L1=L2, and the unit of G1 is Nm / °;

[0050] Step 5: Repeat steps 3 and 4, and the corresponding Φ1 will be changed to Φ2, Φ3, ...Φ which are gradually increased. n , the corresponding F1 changes to F2, F3, ... F which are gradually increased. n , and finally get the torsional stiffness G of n tests i , i=1…n;

[0051] Step 6. Calculate the absolute average torsional stiffness using the following formula:

[0052]

[0053] Step 7. Calculate the standard deviation δ according to the following formula:

[0054]

[0055] Step 8. If each G i Perform the following calculations and judgments: If Then discard the G i Otherwise, keep the G i ;

[0056] Step 9. All the retained G i Then calculate the weighted average value, and the weighted average torsional stiffness G is the final torsional stiffness of the coupling to be tested. In this step, first calculate all the retained G i Then renumber them in sequence to get G1, G2, ...G m , m is a natural number and not greater than n, and the weighted average torsional stiffness G is calculated according to the following formula:

[0057]

[0058] Where ω1, ω2, …ω m They are G1, G2, ...G m The weighted number is obtained according to the conventional method of weighted average calculation.

[0059] The above embodiments are only preferred embodiments of the present invention and are not limitations on the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection and expansion of the patent of the present invention.

Claims

1. A coupling torsional stiffness testing device, comprising a base, characterized in that: It also includes a transmission shaft, a transmission arm, a mounting seat, a first hydraulic cylinder, a first pressure sensor, a mounting bracket, a second hydraulic cylinder, a second pressure sensor and an angular displacement sensor, wherein the mounting seat is mounted on the base, a vertical first mounting plate and a vertical second mounting plate are provided on the mounting seat, the horizontal transmission shaft is rotatably mounted on the first mounting plate, the middle part of the horizontal transmission arm is connected to the transmission shaft, the length direction of the transmission arm is perpendicular to the length direction of the transmission shaft, the angular displacement sensor is mounted on the mounting seat, one end of the transmission shaft is close to the second mounting plate for mounting the coupling to be tested, and the other end is connected to the rotating shaft of the angular displacement sensor, the vertical first hydraulic cylinder is mounted on the base, the first pressure sensor is mounted on the push rod of the first hydraulic cylinder and is located below one end of the transmission arm, the mounting bracket is mounted on the base, the vertical second hydraulic cylinder is mounted on the mounting bracket, the second pressure sensor is mounted below the push rod of the second hydraulic cylinder and is located above the other end of the transmission arm.

2. The coupling torsional stiffness testing device according to claim 1, characterized in that: It also includes a controller, assuming that the distance between the contact point of the transmission arm and the first pressure sensor and the center line of the transmission shaft is L1, and the distance between the contact point of the transmission arm and the second pressure sensor and the center line of the transmission shaft is L2, L1 and L2 are equal, the signal output end of the first pressure sensor, the signal output end of the second pressure sensor, and the signal output end of the angular displacement sensor are respectively connected to the signal input end of the controller, and the control input end of the first hydraulic cylinder and the control input end of the second hydraulic cylinder are respectively connected to the control output end of the controller.

3. The coupling torsional stiffness testing device according to claim 1, characterized in that: The mounting seat includes a first mounting seat and a second mounting seat respectively mounted on the base, the first mounting plate is arranged on the first mounting seat, the angular displacement sensor is mounted on the first mounting seat, and the second mounting plate is arranged on the second mounting seat.

4. The coupling torsional stiffness testing device according to claim 3, characterized in that: There are two first mounting plates, both of which are parallel to the second mounting plate. The transmission shaft passes through corresponding through holes in the two first mounting plates and is connected via bearings respectively. The transmission arm is located between the two first mounting plates.

5. The coupling torsional stiffness testing device according to any one of claims 1 to 4, characterized in that: A transverse central through hole is provided in the middle of the transmission arm and the transmission shaft passes through the central through hole. A tightening sleeve is installed between the transmission shaft and the wall of the central through hole of the transmission arm.

6. The coupling torsional stiffness testing device according to any one of claims 1 to 4, characterized in that: A connecting flange for connecting to the coupling to be tested is provided on one end of the transmission shaft close to the second mounting plate.

7. The coupling torsional stiffness testing device according to any one of claims 1 to 4, characterized in that: The top of the base is flat and is provided with a plurality of mutually parallel inverted "T"-shaped mounting grooves, and the mounting seat and the mounting bracket are respectively connected to the corresponding inverted "T"-shaped connecting pieces in the inverted "T"-shaped mounting grooves.

8. The coupling torsional stiffness testing device according to any one of claims 1 to 4, characterized in that: A connecting column is provided on one end of the transmission shaft close to the angular displacement sensor, and the connecting column is connected to the rotating shaft of the angular displacement sensor through a rigid connector.

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