A floating friction plate applies dynamic and static compound state coupling load test device

Abstract

The application relates to the technical field of floating friction plate testing, and particularly discloses a coupling load testing device for applying dynamic and static combined states to a floating friction plate, which comprises a torque input main shaft, a driven shell, a driving system and a detection module, a plurality of annular separation sheets are arranged on the torque input main shaft, and annular friction plates are arranged between the adjacent two annular separation sheets; a step matched with each annular friction plate is arranged on the inner wall of the driven shell; the driving system is used for setting the rotating speed and the torque of the torque input main shaft; an axial force applying assembly comprises an end cover arranged on the torque input main shaft and a hydraulic actuator connected with the end cover; the hydraulic actuator is used for driving the axial displacement of the end cover along the torque input shaft main shaft, extruding and contacting or moving away from the annular separation sheet located at the outermost side of the assembly opening, the static load of the annular friction plate is realized through the axial force applying assembly, the rotating power of the torque input main shaft is applied to the torque input main shaft by superimposing the torque of the torque input main shaft, and the test of the dynamic load is simulated.

Description

Technical Field

[0001] This invention relates to the field of floating friction plate testing technology, and more specifically to a testing device for applying a combined dynamic and static load to a floating friction plate. Background Technology

[0002] Floating friction plates are key components in mechanical transmission systems, widely used in clutches, brakes, and gearboxes. Their performance directly affects the reliability, durability, and efficiency of the transmission system. In actual operating conditions, floating friction plates not only bear static preload but also are subjected to dynamic alternating loads (such as vibration, impact, and periodic torque), forming a coupled load of dynamic and static conditions. Therefore, accurately simulating and testing the mechanical properties, friction and wear behavior, and fatigue life of floating friction plates under combined dynamic and static loads is of great significance.

[0003] However, existing floating friction pad testing devices and methods still have the following problems: testing equipment mostly focuses on applying a single static or dynamic load, making it difficult to simultaneously simulate the combined static and dynamic loads in actual working conditions. For example, static testing devices cannot introduce dynamic alternating forces, while dynamic fatigue testing machines lack precise control of static preload, resulting in significant deviations between test conditions and actual working conditions.

[0004] In existing technologies, static preload and dynamic load are often applied independently through mechanical or hydraulic systems. However, when they work together, interference can easily occur, leading to low load coupling accuracy. For example, dynamic load may affect the stability of static preload, or static load may have a damping effect on the transmission of dynamic signals, affecting the accuracy of test data.

[0005] Floating friction plates may experience slight displacement or deflection during operation. However, existing testing devices mostly use rigid fixing methods, which cannot truly reflect the dynamic response of the friction plates in a floating state, resulting in distorted test results of friction contact characteristics (such as contact pressure distribution and friction coefficient fluctuation).

[0006] Especially in the vibration response test of multi-plate friction pairs of dampers with multiple friction plates (i.e., simulating non-rigid contact conditions), if the commonly used fixed setting of the separator plates is used, the gap of the friction pair needs to be precisely controlled during the test. Usually, a return spring is needed to ensure that the separator plates can automatically return to their original position after unloading, while maintaining the initial gap. However, when the friction plates rotate at high speed, the resonance frequency of the return spring is easily coupled with the spindle operating speed, causing dynamic interference.

[0007] In summary, existing floating friction pad testing devices and methods suffer from technical problems such as the inability to synchronously couple dynamic and static loads, and the inability to decouple measurements due to dynamic interference of the structure during the testing process. Summary of the Invention

[0008] The purpose of this invention is to provide a testing device for applying a combined dynamic and static load to a floating friction plate, in order to solve the technical problems in the existing floating friction plate testing devices and methods, which are unable to synchronously couple dynamic and static loads and cannot decouple measurements due to dynamic interference of the structure during the testing process.

[0009] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0010] A testing device for applying a coupled dynamic-static load to a floating friction plate includes:

[0011] A torque input spindle is vertically arranged, and a plurality of annular separation plates are arranged at the bottom of the torque input spindle. The annular separation plates are mounted on the torque input spindle by keyway engagement, and annular friction plates are arranged between two adjacent annular separation plates. The keyway engagement allows the annular separation plates to move axially.

[0012] The driven housing is a hollow cylinder with an open bottom forming an assembly port. The torque input spindle enters the driven housing from the top along the axial direction of the driven housing, and the bottom end of the torque input spindle protrudes from the bottom wall of the driven housing. The circumferential edge of the annular friction plate is splined to the inner wall of the driven housing. The driven housing is designed to rotate circumferentially under the action of external force.

[0013] A step is provided on the inner wall of the driven housing to cooperate with each of the annular friction plates. The step is located below the annular friction plate and restricts the axial downward displacement of the annular friction plate.

[0014] The drive system is connected to the torque input spindle and is used to set the speed and torque of the torque input spindle.

[0015] An axial force application assembly includes an end cap disposed on the torque input spindle and a hydraulic actuator connected to the end cap. The end cap is located inside the assembly port, and the hydraulic actuator is used to drive the end cap to move axially along the torque input spindle to press against or move away from the annular separation plate located on the outermost side of the assembly port.

[0016] The detection module includes a torque sensor connected in series on the torque input spindle and a rotary encoder connected to the driven housing.

[0017] In a preferred embodiment of the present invention, the drive system is connected to the end of the torque input spindle via a flexible coupling;

[0018] An axial driver is connected to the end of the torque input spindle that extends out of the assembly port. The axial driver is used to stepwise drive the torque input spindle to move axially upward when the hydraulic actuator drives the end cap away from the annular separator.

[0019] As a preferred embodiment of the present invention, a window is provided on the surface of the driven housing along the axial direction of the driven housing, a transparent cover is installed on the window, and a laser displacement sensor and an infrared sensor are provided on the transparent cover.

[0020] In a preferred embodiment of the present invention, the driven housing is mounted on a horizontally positioned test platform via a bearing seat;

[0021] Multiple supports are evenly arranged on the inner wall of the driven housing. The supports are along the axial direction of the driven housing, and an internal spline is formed between two adjacent supports. An external spline that mates with the internal spline is provided on the outer edge of the annular friction plate.

[0022] A step is provided within the internal spline along the length of the internal spline to mate with each of the annular friction plates.

[0023] As a preferred embodiment of the present invention, a rotating cavity for mounting the driven housing is provided on the test platform;

[0024] An installation groove is provided on the outer side wall of the driven housing along the axial direction of the driven housing. The installation groove penetrates the inner and outer surfaces of the driven housing. The outer side of the bracket is fitted into the installation groove and protrudes from the surface of the driven housing.

[0025] A rotating ring frame is fitted onto the driven housing. The outer wall of the rotating ring frame contacts the inner wall of the rotating cavity. A lateral force sensor is provided on the surface of the rotating cavity that contacts the rotating ring frame.

[0026] As a preferred embodiment of the present invention, the hydraulic actuator includes a pneumatic cylinder, a power transmission arm, and an arc-shaped block. The output end of the pneumatic cylinder is connected to one end of the power transmission arm, and the other end of the power transmission arm is connected to the arc-shaped block. The arc-shaped block is located on the outer edge of the end cap.

[0027] As a preferred embodiment of the present invention, the steps on the inner wall of the driven housing are arranged with equal height differences from top to bottom in the axial direction of the driven housing.

[0028] As a preferred embodiment of the present invention, the step has a triangular cross-section in the axial direction of the driven housing.

[0029] As a preferred embodiment of the present invention, it further includes a rotation drive assembly, which includes two vertically arranged fixed seats. Both sides of the test platform are connected to the corresponding fixed seats through rotating shafts. A servo motor is arranged on the fixed seat, and the output end of the servo motor is connected to the rotating shaft. The servo motor drives the test platform to rotate from a horizontal state to a vertical state.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] This invention constructs a contact fixture for annular friction plates and annular separation plates using a vertically set torque input spindle, and applies static loads, dynamic loads, and combined loads to the annular friction plates and annular separation plates using an axial force application component and a drive system, thereby simulating non-rigid contact conditions of multiple friction plates. Attached Figure Description

[0032] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0033] Figure 1 This is a partial cross-sectional structural diagram of the overall driven housing according to an embodiment of the present invention;

[0034] Figure 2 This is a schematic cross-sectional view of a portion of the overall structure of an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the structure of the driven housing with a mounting groove according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0037] Figure 5 This is a bottom view of the driven housing structure according to an embodiment of the present invention;

[0038] Figure 6 This is a schematic diagram of the overall structure of the rotation drive assembly according to an embodiment of the present invention.

[0039] The labels in the diagram represent the following:

[0040] 1. Torque input spindle; 2. Annular separator; 3. Annular friction plate; 4. Driven housing; 5. Step; 6. Drive system; 7. Axial force application assembly; 8. Assembly port; 9. Torque sensor; 10. Rotary encoder; 11. Flexible coupling; 12. Axial drive; 13. Window; 14. Transparent cover; 15. Bearing housing; 16. Test platform; 17. Bracket; 18. Internal spline; 19. External spline; 20. Mounting slot; 21. Rotating ring frame; 22. Lateral force sensor; 23. Rotary drive assembly; 24. Fixed base; 25. Servo motor; 26. Rotating cavity;

[0041] 71. End cap; 72. Hydraulic actuator; 73. Pneumatic cylinder; 74. Power transmission arm; 75. Arc block. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] The core components of a testing device for floating friction plates generally include:

[0044] Drive system:

[0045] Rotary power unit: Servo motor or frequency converter motor drives the spindle through a coupling to simulate dynamic working conditions (such as adjustable speed range of 0~5000 rpm).

[0046] Linear actuation unit: A hydraulic cylinder or electric cylinder applies a static axial load (pressure range typically 0~10 kN) and is controlled in a closed loop by a force sensor.

[0047] Floating friction plate mechanism

[0048] Floating support design: The friction plate is connected to the spindle via a spline or ball joint structure, allowing for axial micro-movement (float amount of approximately ±1mm) to adapt to the mating surface (separation plate).

[0049] Dual surface (separation plate): fixed to the test bench base, the surface can be coated with a wear-resistant coating (such as WC-Co), with a hardness of HRC 60 or above.

[0050] Composite load application system:

[0051] Dynamic load: High-frequency vibration (up to 1kHz) is superimposed by an eccentric wheel or electromagnetic exciter, and the amplitude is monitored by a laser displacement sensor.

[0052] Static load: The hydraulic system maintains a constant pressure, or a stepped loading is achieved through PID control.

[0053] The monitoring system includes:

[0054] Contact status detection:

[0055] Contact resistance method: The friction plate signal is derived by brush, and the contact / separation point is determined by the resistance change point.

[0056] Fiber optic displacement sensor: Real-time monitoring of the axial displacement of the friction plate (resolution 0.1μm).

[0057] Simultaneous acquisition of multiple physical quantities: torque sensor (range ±200Nm), temperature infrared thermal imager (sampling rate 100Hz), acoustic emission sensor (bandwidth 20kHz~1MHz).

[0058] The contact state between the friction plate and the separation plate is as follows:

[0059] During the static contact stage (static load application stage), under the initial preload, the friction plate and the separation plate are in surface contact. The contact pressure distribution is calibrated by a pressure-sensitive film (such as Fuji Prescale), and usually exhibits an edge effect (pressure peak at 70% of the radius).

[0060] In the dynamic friction stage (that is, the stage of applying coupled loads in the dynamic-static coincident state),

[0061] Boundary lubrication condition: At low speeds (<50 rpm), localized adhesion-slippage occurs on the contact surface, with the friction coefficient μ fluctuating between 0.1 and 0.3.

[0062] Mixed lubrication state: In the medium-to-high speed stage (200~2000rpm), the contact ratio of micro-protrusions decreases, the hydrodynamic effect is significant, and μ drops to 0.05~0.1.

[0063] Contact instability: Flutter may be induced at the critical speed. The vibration spectrum (characteristic frequency is usually in the range of 200~500Hz) can be analyzed by FFT.

[0064] In order to simulate the actual working conditions of multiple friction plates, the main shaft for torque input is usually placed horizontally to match the working conditions of multi-plate clutches in actual applications. However, in the simulation process, in the design of the floating separator (paired plate) of the floating friction plate, a return spring is needed to install the separator to ensure that the separator can automatically return to its position after unloading and maintain the initial gap. During the application of dynamic load, centrifugal force may cause the separator to expand slightly outward, and the spring needs to compensate for this displacement. Moreover, the spring resonance frequency must avoid the main shaft working speed when rotating at high speed, otherwise dynamic interference is likely to occur.

[0065] Therefore, such as Figures 1 to 5 As shown, this embodiment provides a testing device for a coupled load of dynamic and static combined state applied to a floating friction plate, including a torque input spindle 1. The torque input spindle 1 is vertically arranged, that is, in this embodiment, the test condition of the floating friction plate and the separation plate is constructed by placing the spindle 1 horizontally. Multiple annular separation plates 2 are arranged at the bottom of the torque input spindle 1. The annular separation plates 2 are installed on the torque input spindle 1 by keyway engagement. An annular friction plate 3 is arranged between two adjacent annular separation plates 2. The keyway engagement allows the annular separation plates 2 to move axially.

[0066] like Figure 2 As shown, this embodiment takes 5 annular separation plates (F1, F2, F3, F4, F5) and 4 annular friction plates (M1, M2, M3, M4) as an example. In the floating design of the annular friction plates, the inner wall of the driven housing 4 is connected by the spline of the circumferential edge of the annular friction plate 3, so that the radial direction of the annular friction plate 3 is restricted, the circumferential direction is connected to the driven housing 4, and its axial direction allows micro-movement.

[0067] The driven housing 4 is a hollow cylinder with an open bottom forming an assembly port 8. The torque input spindle 1 enters the driven housing 4 from the top along the axial direction of the driven housing 4, and the bottom end of the torque input spindle 1 protrudes from the bottom wall of the driven housing 4. The circumferential edge of the annular friction plate 3 is splined to the inner wall of the driven housing 4. The driven housing 4 is set to rotate circumferentially under the action of external force.

[0068] A step 5 is provided on the inner wall of the driven housing 4 to cooperate with each annular friction plate 3. The step 5 is located below the annular friction plate 3 and restricts the axial downward displacement of the annular friction plate 3.

[0069] The drive system 6 is connected to the torque input spindle 1 and is used to set the speed and torque to the torque input spindle 1.

[0070] The axial force application assembly 7 includes an end cover 71 disposed on the torque input spindle 1 and a hydraulic actuator 72 connected to the end cover 71. The end cover 71 is located inside the assembly port 8. The hydraulic actuator 72 is used to drive the end cover 71 to move axially along the torque input spindle 1, pressing against or away from the annular separation plate 2 located on the outermost side of the assembly port 8.

[0071] The detection module includes a torque sensor 9 connected in series on the torque input spindle 1 and a rotary encoder 10 connected to the driven housing 4.

[0072] This implementation method is as follows:

[0073] In the initial state:

[0074] Drive system 6 stops, torque input spindle 1 stops, hydraulic actuator 72 of axial force application component 7 stops, and detection module stops.

[0075] The axial edges of each annular friction plate 3 on the torque input spindle 1 overlap on the step 5, and the annular friction plate 3 and the annular separation plate 2 are initially bonded, i.e., F2 and M1, F3 and M2, F4 and M3, F5 and M4. The axial position of F1 on the torque input spindle 1 is fixed, and during this process, the initial bonding contact pressure between the annular friction plate 3 and the annular separation plate 2 is uniform (the interval between F2 and M1, F3 and M2, F4 and M3, F5 and M4 needs to take into account the thickness of the annular friction plate 3 and the annular separation plate 2).

[0076] During the static load application phase:

[0077] The hydraulic actuator 72 of the axial force application component 7 receives a signal and pushes the end cover 71 upward along the axial direction of the torque input spindle 1, thereby stacking the annular friction plate 3 and the annular separation plate 2, and then pre-pressing in the order of F5 and M4 - F4 and M3 - F3 and M2 - F2 and M1 - F1 until the set pressure range is reached.

[0078] The dynamic rotation start-up phase includes two testing aspects:

[0079] First, in the initial state, when the initial contact pressure between the annular friction plate 3 and the annular separating plate 2 is uniform (hydraulic actuator 72 stops), the drive system 6 is started, and the torque input spindle 1 is gradually accelerated to the target speed. The wear condition of the annular friction plate in the "zero pressure" state is measured. This "zero pressure" refers to the friction effect of the annular friction plate 3 in surface contact only under the influence of the gravity of the annular separating plate 2. This situation can be used to simulate the "free state" of the annular friction plate 3 in actual working conditions. This "free state" is the friction condition when the torque input spindle 1 is horizontally positioned, and the regular vibration caused by the working environment causes the annular friction plate 3 and the annular separating plate 2 to come into contact.

[0080] Furthermore, in this case, there is no need for a return spring to control the position of the annular separator 2, nor is it necessary to adjust the elastic coefficient of the return spring during operation to adjust the contact pressure between the annular friction plate 3 and the annular separator 2. The purpose is to decouple the axial force and radial force on the friction plate.

[0081] That is, between multiple annular friction plates and multiple annular separation plates in "completely compressed contact", the axial force can be ignored, and the radial force is provided by the contact between the annular friction plates and the annular separation plates.

[0082] Before the multiple annular friction plates and multiple annular separation plates are in "full pressure contact", the information can be obtained by measuring the data changes of the torque sensor 9 of the torque input spindle 1 or by measuring the data of the rotary encoder 10.

[0083] After multiple annular friction plates and multiple annular separation plates are in "complete pressure contact", the static load application stage begins.

[0084] At this time, the annular friction plate 3 is rotating and is only subjected to radial force due to the increase in speed, that is, the friction plate is subjected to centrifugal force generated by the frictional contact of the annular separation plate 2.

[0085] At this time, each annular friction plate 3 is still attached to each step 5. The spacing between each step is X1, X2, X3, X4, and they are evenly distributed (the thickness of the annular friction plate 3 and the annular separation plate 2 needs to be considered). The steps 5 on the inner wall of the driven housing 4 have an evenly distributed height difference from top to bottom along the axial direction of the driven housing 4.

[0086] Secondly, after the static load is applied, the drive system 6 gradually accelerates the torque input to the spindle 1 to the target speed (e.g., 1000-3000 rpm). During this process, the friction plates slightly expand outward due to centrifugal force, and the contact surface undergoes micro-slippage. This is activated by the oil injection system, forming an oil film shear layer. This can then be used to test the load under the condition of axial and radial force coupling, as the axial force increases. At this point, it is necessary to consider offsetting the weight of the four annular friction plates 3 and the four annular separation plates 2 when applying the axial force.

[0087] Composite load testing phase:

[0088] The specific actions of the test device are as follows: the hydraulic actuator 72 applies axial pressure to the pre-pressurized friction pair through the end cover 71, causing periodic fluctuations (simulating braking pulses), and the torque input spindle 1 is applied by the drive system 6 to cause sudden speed changes (such as a step speed reduction of 50% to simulate impact).

[0089] During the termination and uninstallation phase:

[0090] The drive system 6 slowly stops, and the axial force of the hydraulic actuator 72 is unloaded.

[0091] Furthermore, in this embodiment, when specifically designing a floating separator, especially under special operating conditions, the performance of the friction plate needs to be accurately characterized through multi-parameter collaborative measurement. These parameters can be divided into two categories: "directly measured parameters" and "derived performance indicators." The following is a detailed analysis of the specific measurement methods and their correlation with the friction plate performance:

[0092] In this embodiment, parameters can also be measured directly, for example:

[0093] Axial displacement: Keyence IL series laser displacement sensor / magnetostrictive sensor, MTS magnetic scale ±0.001mm;

[0094] Contact pressure: Piezoelectric thin film sensor (embedded in annular separator) Tekscan FlexiForce ±1% FS;

[0095] Friction torque: Torque sensor 9 (torque input spindle 1 and torque input spindle 1 connected to axial drive 9) HBM T40B ±0.1% FS;

[0096] Temperature field distribution: Infrared thermal imager + embedded thermocouple FLIR A65, K-type thermocouple ±1°C;

[0097] Vibration acceleration: Triaxial accelerometer (bearing housing 15) PCB 356A01 ±0.5 m / s²;

[0098] Slip rate: The differential displacement of the rotary encoder 10 and the annular separator 2 of the main shaft is calculated as Heidenhain ECN413±0.05%.

[0099] Among them, axial displacement characterizes the floating coordination and pressure equalization capability. In multi-plate friction pairs (a friction pair refers to the fit between an annular friction plate and an annular separation plate), the consistency of the gradual displacement of each annular separation plate during the test reflects the uniformity of pressure distribution, specifically including:

[0100] Dynamic fluctuations in contact pressure: characterize the ability to resist vibration loads;

[0101] The amplitude (ΔP) and frequency of pressure fluctuations reflect the damping characteristics of the friction plate;

[0102] Friction coefficient-slip ratio curve: characterizes dynamic friction stability;

[0103] Vibration spectrum: characterizes NVH performance and optimizes the keyway design of friction plates and separator plates to disperse vibration energy.

[0104] Therefore, this embodiment uses a floating device for the annular separation plate. In this state, by monitoring the five-dimensional parameters of "displacement-pressure-torque-temperature-vibration", the floating coordination, dynamic stability, thermal decay resistance, and NVH performance of the floating friction plate 3 can be quantitatively characterized. Ultimately, this testing device can establish a multi-parameter fusion performance testing method.

[0105] In this embodiment, the annular separator 2 is connected to the main shaft via a spline or sliding key, allowing limited axial displacement (and without the need for a return spring). The torque input main shaft 1 does not require hard-limiting annular friction plate 3 or annular separator 2. The annular separator 2 can adjust its position under static pressure load along with the floating friction plate 3.

[0106] During the test, when the hydraulic actuator is pressurized, the annular separator plate 2 and the annular friction plate 3 move axially synchronously, forming a gradual dynamic equilibrium state of the friction pair (one friction plate and one separator plate) until it stabilizes and reaches the final pre-pressurized state. The gradual dynamic equilibrium state of the friction pair in this embodiment can simulate the non-rigid contact condition of the annular friction plate 3 and the annular separator plate 2 (such as the vibration response test of a multi-plate friction pair of a damper).

[0107] Compared to the method of installing the annular separation plate 2 by means of a reset spring, this embodiment ensures that the friction pair remains in contact during the unloading process. Therefore, the required oil film shear layer still exists during the unloading process, and the problem of oil film layer failure can be avoided.

[0108] In this embodiment, the drive system 6 is connected to the end of the torque input spindle 1 via a flexible coupling 11, which is used to provide stable unloading rotation of the torque input spindle 1 during unloading.

[0109] Since the floating friction test of multiple friction plates and multiple separation plates in the test device is conducted in a closed space (that is, in the driven housing 4), the infrared thermal imager is blocked by the rotating parts and can only measure the temperature on the outside of the friction ring. The transient temperature rise at the contact interface (such as local hot spots > 800℃) is difficult to obtain directly.

[0110] Therefore, in this embodiment, an opening 13 along the axial direction of the driven housing 4 is provided on the surface of the driven housing 4. The length and size of this opening 13 are designed to allow observation of all the annular friction plates 3 and annular separation plates 2 when they are superimposed under axial load. Of course, to ensure structural stability and multi-angle observation, multiple openings 13 can be uniformly provided on the driven housing 4.

[0111] A transparent cover 14 is installed on the window 13. A laser displacement sensor and an infrared sensor are set on the transparent cover 14. The axial displacement state of the annular friction plate 3 and the annular separation plate 2 during the test can be obtained by the laser displacement sensor set on the transparent cover, and the surface temperature distribution state of the separated friction pair can be obtained by the infrared sensor.

[0112] However, even with the window 13 set, the condition of the circumferential edge of the friction pair can only be detected by the laser displacement sensor and infrared sensor through the window 13. It is impossible to obtain the friction and temperature rise of the contact surface of the annular friction plate 3 and the annular separation plate 2.

[0113] Therefore, in this embodiment, an axial driver 12 is connected to the end of the torque input spindle 1 extending from the assembly port 8. The axial driver 12 is used to step drive the torque input spindle 1 to move axially upward when the hydraulic actuator 72 drives the end cover 71 away from the annular separator 2. During the test, the axial driver 12 cooperates with the torque input of the drive system 6 to cause the torque input spindle 1 to undergo axial displacement. This causes the annular separator 2 to follow the axial displacement of the torque input spindle 1 when it obtains rotational inertia. As a result, a gap is generated between the annular separator 2 and the annular friction plate 3. At this time, the displacement can be obtained by a laser displacement sensor, and the surface condition of the contact between the annular friction plate 3 and the annular separator 2 can be obtained by scanning with an infrared sensor, or the surface morphology of the annular friction plate 3 can be scanned by the probe of a white light interferometer.

[0114] In this way, this embodiment can directly obtain the wear of the annular friction plate 3 at different stages, speeds, and times under simulated working conditions. It does not require disassembling the friction pair for measurement.

[0115] During this process, based on the measurement results, the centrifugal force at high speed leads to enhanced edge contact. Finite element simulation verification of the annular friction plate 3 and the annular separation plate 2 under working conditions is required. For the floating characteristics of the annular friction plate 3, automatic tilt compensation is required during non-uniform wear to avoid local overheating. Since the oil film breaks down at this time, adhesive wear is caused. Abnormal signals need to be captured by acoustic emission sensors. These can be achieved by directly setting existing sensors on the transparent cover 14.

[0116] Of course, to ensure the rotational stability of the driven housing 4 during the test, an electric slip ring is required, that is, an electric slip ring is installed on the bearing seat 15 to supply power to the sensor and other equipment. In this embodiment, the driven housing 4 is mounted on a horizontally arranged test platform 16 via the bearing seat 15.

[0117] In the floating design of the annular friction plate 3, multiple supports 17 are evenly arranged on the inner wall of the driven housing 4. The supports 17 are along the axial direction of the driven housing 4, and an internal spline 18 is formed between two adjacent supports 17. An external spline 19 that mates with the internal spline 18 is provided on the outer edge of the annular friction plate 3. The circumferential displacement of the annular friction plate 3 is restricted by the engagement of the internal spline 18 and the external spline 19, while driving the driven housing 4 to rotate. Furthermore, a step 5 that mates with each annular friction plate 3 is provided within the internal spline 18 along its length.

[0118] A rotating cavity 26 is provided on the test platform 16 for mounting the driven housing 4. It is used to mount the driven housing 4 and can provide relative rotation of the driven housing 4. Of course, the relative friction between the two needs to be considered in the calculation of the test results, or the relative friction can be reduced by bearing connection.

[0119] In this embodiment, the lateral force during the test process also needs to be considered. If the lateral force during the rotation of the driven housing 1 is directly measured, the gap between the annular friction plate 3 and the driven housing 4 will affect the transmission process.

[0120] For this purpose, an installation groove 20 is provided on the outer side wall of the driven housing 4 along the axial direction of the driven housing 4. The installation groove 20 penetrates the inner and outer surfaces of the driven housing 4. The outer side of the bracket 17 is fitted into the installation groove 20 and protrudes from the surface of the driven housing 4.

[0121] Therefore, a rotating ring frame 21 is mounted on the driven housing 4. The outer wall of the rotating ring frame 21 contacts the inner wall of the rotating cavity 26. A lateral force sensor 22 is provided on the surface of the rotating cavity 26 that contacts the rotating ring frame 21. The lateral force sensor 22 can be a force sensor. A multi-dimensional force sensor (such as a triaxial force sensor) can be installed on the driven housing 4 or the bearing seat 15 to simultaneously measure the lateral force (lateral / axial) and radial force. Alternatively, strain gauges can be used and attached to the rotating support 21 to form a Wheatstone bridge. The lateral force can be indirectly calculated through strain changes. Or, a piezoelectric sensor can be used to detect the instantaneous lateral force during the rotation of the rotating ring frame 21. It has good high-frequency response and is suitable for dynamic measurement.

[0122] The hydraulic actuator 72 includes a pneumatic cylinder 73, a power transmission arm 74, and an arc block 75. The output end of the pneumatic cylinder 73 is connected to one end of the power transmission arm 74, and the other end of the power transmission arm 74 is connected to the arc block 75. The arc block 75 is located on the outer edge of the end cover 71.

[0123] Of course, the pneumatic cylinder 73 in this embodiment can also be replaced by a magnetorheological actuator to replace the hydraulic system (response time <5ms) to improve the accuracy of dynamic load.

[0124] In this embodiment, the step 5 has a triangular cross section in the axial direction of the driven housing 4, which reduces the contact surface between the step 5 and the annular friction plate 3 and reduces the impact of the step 5 on the annular friction plate 3.

[0125] like Figure 6 As shown, this embodiment also includes a rotation drive assembly 23, which includes two vertically arranged fixed seats 24. Both sides of the test platform 16 are connected to the corresponding fixed seats 24 through rotating shafts. A servo motor 25 is arranged on the fixed seat 24. The output end of the servo motor 25 is connected to the rotating shaft. The servo motor 25 drives the test platform 16 to rotate from a horizontal state to a vertical state, that is, the test state can be adjusted to different angle states, thereby simulating the inconsistent axial floating of the annular friction plate 3, that is, the vibration spectrum of the annular friction plate 3, and the phase difference between the floating phase of the separation plate and the excitation force of the annular friction plate 3.

[0126] The above embodiments are merely exemplary embodiments of this application and are not intended to limit this application. The scope of protection of this application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to this application within its substance and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of this application.

Claims

1. A testing device for a coupled load of a floating friction plate under dynamic and static combined state, characterized in that, include: A torque input spindle (1) is vertically arranged. Multiple annular separation plates (2) are arranged at the bottom of the torque input spindle (1). The annular separation plates (2) are mounted on the torque input spindle (1) by keyway engagement. Annular friction plates (3) are arranged between two adjacent annular separation plates (2). The keyway engagement allows the annular separation plates (2) to move axially. The driven housing (4) is hollow cylindrical. The bottom of the driven housing (4) is open to form an assembly port (8). The torque input spindle (1) enters the driven housing (4) from the top along the axial direction of the driven housing (4). The bottom end of the torque input spindle (1) passes through the bottom wall of the driven housing (4). The circumferential edge of the annular friction plate (3) is splined to the inner wall of the driven housing (4). The driven housing (4) is set to rotate circumferentially under the action of external force. A step (5) is provided on the inner wall of the driven housing (4) to cooperate with each of the annular friction plates (3). The step (5) is located below the annular friction plate (3) and restricts the axial downward displacement of the annular friction plate (3). The drive system (6) is connected to the torque input spindle (1) and is used to set the speed and torque to the torque input spindle (1); The axial force application assembly (7) includes an end cap (71) disposed on the torque input spindle (1) and a hydraulic actuator (72) connected to the end cap (71). The end cap (71) is located inside the assembly port (8). The hydraulic actuator (72) is used to drive the end cap (71) to move axially along the torque input spindle (1) to press against or move away from the annular separation piece (2) located on the outermost side of the assembly port (8). The detection module includes a torque sensor (9) connected in series on the torque input spindle (1) and a rotary encoder (10) connected to the driven housing (4).

2. The device for testing coupled loads of a floating friction plate under dynamic and static combined states according to claim 1, characterized in that, The drive system (6) is connected to the end of the torque input spindle (1) via a flexible coupling (11); An axial driver (12) is connected to the end of the torque input spindle (1) that extends out of the assembly port (8). The axial driver (12) is used to step drive the torque input spindle (1) to move axially upward when the hydraulic actuator (72) drives the end cap (71) away from the annular separator (2).

3. The device for testing coupled loads of a floating friction plate under dynamic and static combined states according to claim 1, characterized in that, A window (13) is provided on the surface of the driven housing (4) along the axial direction of the driven housing (4), a transparent cover (14) is installed on the window (13), and a laser displacement sensor and an infrared sensor are provided on the transparent cover (14).

4. The testing device for a coupled load of a floating friction plate under dynamic and static combined state according to claim 1, characterized in that, The driven housing (4) is mounted on a horizontally positioned test platform (16) via a bearing seat (15); Multiple supports (17) are uniformly arranged on the inner wall of the driven housing (4). The supports (17) are arranged along the axial direction of the driven housing (4), and an inner spline (18) is formed between two adjacent supports (17). An outer spline (19) that mates with the inner spline (18) is provided on the outer edge of the annular friction plate (3). A step (5) is provided in the inner spline (18) along the length direction of the inner spline (18) to cooperate with each of the annular friction pieces (3).

5. The device for testing coupled dynamic and static loads on a floating friction plate according to claim 4, characterized in that, A rotating cavity (26) for mounting the driven housing (4) is provided on the test platform (16). An installation groove (20) is provided on the outer side wall of the driven housing (4) along the axial direction of the driven housing (4). The installation groove (20) penetrates the inner and outer surfaces of the driven housing (4). The outer side of the bracket (17) is fitted in the installation groove (20). The outer side of the bracket (17) protrudes from the surface of the driven housing (4). A rotating ring frame (21) is fitted on the driven housing (4). The outer wall of the rotating ring frame (21) contacts the inner wall of the rotating cavity (26). A lateral force sensor (22) is provided on the surface of the rotating cavity (26) that contacts the rotating ring frame (21).

6. The testing device for applying a combined dynamic and static load to a floating friction plate according to claim 2, characterized in that, The hydraulic actuator (72) includes a pneumatic cylinder (73), a power transmission arm (74), and an arc block (75). The output end of the pneumatic cylinder (73) is connected to one end of the power transmission arm (74), and the other end of the power transmission arm (74) is connected to the arc block (75). The arc block (75) is located on the outer edge of the end cap (71).

7. The device for testing coupled loads of a floating friction plate under dynamic and static combined states according to claim 1, characterized in that, The steps (5) on the inner wall of the driven housing (4) are arranged with equal height differences from top to bottom in the axial direction of the driven housing (4).

8. The testing device for a coupled load of dynamic and static composite state applied to a floating friction plate according to claim 1, characterized in that, The step (5) has a triangular cross section in the axial direction of the driven housing (4).

9. The device for testing coupled loads of a floating friction plate under dynamic and static combined states according to claim 4, characterized in that, It also includes a rotation drive assembly (23), which includes two vertically arranged fixed seats (24). Both sides of the test platform (16) are connected to the corresponding fixed seats (24) through a rotating shaft. A servo motor (25) is provided on the fixed seat (24). The output end of the servo motor (25) is connected to the rotating shaft. The servo motor (25) drives the test platform (16) to rotate from a horizontal state to a vertical state.

Images