CN-121977838-A - Joint bearing high-temperature environment comprehensive fatigue life testing device and testing method

CN121977838ACN 121977838 ACN121977838 ACN 121977838ACN-121977838-A

Abstract

The invention belongs to the technical field of joint bearing comprehensive performance test, and particularly relates to a joint bearing high-temperature environment comprehensive fatigue life test device and a joint bearing high-temperature environment comprehensive fatigue life test method. The testing device comprises an axial force application component, a bearing loading component, a deflection application component and a heating component, wherein the bearing loading component provides compound motion freedom degree through a nested deflection and pitching support, the deflection application component eliminates motion interference through a double-shaft linear driving matched floating decoupling structure, and the heating component realizes high-temperature working condition simulation. The testing method is based on the device, and is completed through assembly debugging, parameter setting, temperature rising and heat preservation, parameterized loading testing and performance detection, a deflection movement mapping calculation formula is deduced by constructing a deflection control plane and a coordinate system, movement calculation is simplified, multi-field coupling simulation of axial load, compound deflection and high temperature is realized, actual service conditions of the bearing are accurately restored, and a scientific testing platform is provided for bearing durability and reliability evaluation.

Inventors

TIAN BOWEN
SONG HAILONG
XIE XIN
Shang can
Bu Jiawen

Assignees

西北工业大学太仓长三角研究院

Dates

Publication Date: 20260505
Application Date: 20260311

Claims (10)

1. The comprehensive fatigue life testing device for the high-temperature environment of the joint bearing is characterized by comprising an axial force application assembly, a bearing loading assembly and a heating assembly, wherein the axial force application assembly is used for providing controlled axial stretching or compression load for the joint bearing to be tested, the bearing loading assembly is connected with the axial force application assembly and comprises a deflection bracket (301) and a pitching bracket (302) which are mutually nested and in linkage fit, the deflection bracket is used for fixing the joint bearing to be tested and providing the joint bearing with composite degrees of freedom of horizontal deflection and pitching motion, the deflection application assembly is in linkage with the bearing loading assembly and drives the bearing loading assembly to complete preset space composite deflection motion through a double-shaft linear driving mechanism matched with a floating decoupling structure, and the heating assembly is sleeved on the periphery of the bearing loading assembly and used for simulating high-temperature testing working conditions.
2. The device for testing the comprehensive fatigue life of the high-temperature environment of the spherical plain bearing according to claim 1, wherein the axial force application assembly comprises a bracket (101), an upper force application rod (105) and a lower force application rod (104) which are coaxially arranged on the bracket (101), at least two screw rods (102) which are symmetrically arranged on the bracket (101) and synchronously rotate, and a lifting block (103) which spans between the screw rods (102), the lifting block (103) is in transmission fit with the screw rods (102), the lower force application rod (104) is arranged on the top of the lifting block (103), a force receiving sensor (106) is fixed on the top of the bracket (101), the top end of the upper force application rod (105) is connected with the force receiving sensor (106) and extends downwards in the vertical direction, and the screw rods (102) drive the lifting block (103) to lift so as to apply axial stretching or compression load through the upper force application rod (105) and the lower force application rod (104).
3. The joint bearing high-temperature environment comprehensive fatigue life testing device according to claim 2 is characterized in that the deflection support (301) is of a U-shaped structure, the bottom of the deflection support is rotatably connected with the lower force application rod (104) to achieve horizontal deflection, the pitching support (302) comprises a frame-shaped pitching frame (3021) and pin shafts (3022) symmetrically arranged on two sides of the pitching frame (3021), the two pin shafts (3022) are respectively rotatably matched with two sides of the deflection support (301), an outer ring (502) of the joint bearing is fixedly arranged at the bottom end of the upper force application rod (105) or connected with the outer ring (502) of the installation bearing through a bearing installation block (303), and the pitching frame (3021) locks the inner ring (501) through pins (304) penetrating through the center position and the joint bearing inner ring (501) to enable the inner ring (501) to synchronously move along with the pitching support (302).
4. The device for testing the comprehensive fatigue life of the high-temperature environment of the spherical plain bearing according to claim 3, wherein the double-shaft linear driving mechanism comprises a first linear module (201) installed on the support (101) and a second linear module (202) installed on a sliding table of the first linear module (201), the moving directions of the first linear module (201) and the second linear module (202) are mutually perpendicular, the floating decoupling structure comprises a cross rod (203) rotatably connected to the sliding table of the second linear module (202), a sliding sleeve (204) installed on the cross rod (203) through a revolute pair, and a swinging rod (205) penetrating through the sliding sleeve (204), the swinging rod (205) is in sliding fit with the sliding sleeve (204), and the extending end of the swinging rod (205) is connected with the bearing loading assembly to drive an inner ring (501).
5. The device for testing the comprehensive fatigue life of the high-temperature environment of the spherical plain bearing according to claim 4, wherein the cross rod (203) adopts a rod body offset structure, so that the rotation axis of the cross rod (203) is intersected with the axis of the central through hole of the sliding sleeve (204).
6. A method for testing the comprehensive fatigue life of a spherical plain bearing in a high-temperature environment based on the device of claim 5, comprising the following steps: s1, device assembly and bearing installation, namely completing the integral construction of a testing device, fixing an outer ring (502) of a joint bearing to be tested at the bottom of an upper force application rod (105), and locking an inner ring (501) in a pitching frame (3021) of a pitching bracket (302) through a pin (304); S2, normal-temperature no-load pre-swing debugging, namely under the condition of no axial load at normal temperature, starting a deflection applying assembly to drive the inner ring (501) to finish horizontal deflection motion and pitching motion, and controlling a swinging rod (205) of the deflection applying assembly to return after the debugging is finished; s3, setting test parameters, namely setting a total test duration, an axial force periodic function, a horizontal azimuth angle time function and a pitch angle time function of the compound yaw motion, a test target temperature and a temperature fluctuation range according to the actual working condition of the joint bearing to be tested; S4, heating and preserving heat of the test environment, namely starting a heating sleeve (401) of the heating assembly, monitoring and feeding back temperature data in real time through a temperature sensor of the heating sleeve, and adjusting heating power of the heating wire to enable the temperature of the test environment to be stable within the test target temperature and the temperature fluctuation range; S5, a parameterized loading test is carried out, namely an axial force application assembly and a deflection application assembly are synchronously started, the axial force application assembly applies alternating axial load according to the axial force periodic function, the deflection application assembly drives the inner ring (501) to complete preset compound deflection movement based on a deflection movement mapping calculation algorithm, and load and temperature data are acquired in real time through a stress sensor (106) and a temperature sensor in the test process until the set total test duration is completed or the test is terminated in advance due to bearing damage; s6, cooling and performance detection after testing, namely closing all the components, naturally cooling the joint bearing to be tested to the room temperature, removing the bearing, performing performance detection, and judging whether the fatigue life of the bearing is qualified or not according to the detection result.
7. The method for testing the comprehensive fatigue life of the high-temperature environment of the knuckle bearing according to claim 6, wherein in the step S5, the yaw motion mapping calculation algorithm comprises the steps of defining a space direction which is perpendicular to a motion direction of a first linear module (201) and a motion direction of a second linear module (202) at the same time as a Y direction, defining a plane which is perpendicular to the Y direction and in which a rotation axis of a cross rod (203) is located as a yaw control plane, establishing a plane rectangular coordinate system on the yaw control plane, defining a projection point of a central point of an inner ring (501) of the knuckle bearing as a coordinate origin, defining the motion direction of the first linear module (201) as an X axis, defining the motion direction of the second linear module (202) as a Z axis, defining a horizontal azimuth angle A and a pitch angle B of the inner ring (501) at the same time, deriving a mapping relation between coordinates of the reference point in the coordinate system and the horizontal azimuth angle A and the pitch angle B, performing differential operation on a time function of coordinates of the reference point to obtain linear displacement of the first linear module (201) and the second linear module (202), and driving the linear module.
8. The method for testing the comprehensive fatigue life of the spherical plain bearing in the high-temperature environment according to claim 6, wherein in step S3: The axial force periodic function is F=500×sin (pi×t), wherein the unit of F is newton, t is test time, the unit is s, the axial tension is applied to the joint bearing when F is positive value, and the axial pressure is applied to the joint bearing when F is negative value; the period of the horizontal azimuth angle A and the pitch angle B is 20 seconds, and the period of the horizontal azimuth angle A and the pitch angle B is divided into two stages in a single period, specifically: Horizontal azimuth time function A (t) is 0 to 10 seconds, A (t) =6° x [1- |t-5|/5 ]. Times.sin ((2pi) ×t), and A (t) =0° is 10 to 20 seconds; Pitch time function B (t) is 0 to 10 seconds, B (t) =0°, and 10 to 20 seconds, B (t) =6× [1- |t-15|/5] ×sin ((2pi) ×t).
9. The method for testing the comprehensive fatigue life of the high-temperature environment of the spherical plain bearing according to claim 8, wherein in the yaw movement mapping calculation algorithm, a mapping formula of coordinates of a reference point and a horizontal azimuth angle A and a pitch angle B is C1=L×tan (A), C2=L×tan (B); based on the time functions of the horizontal azimuth angle and the pitch angle, the dynamic change function of the coordinate of the reference point is obtained as C1 (t) =L×tan [ A (t) ], and C2 (t) =L×tan [ B (t) ]; Wherein, C1 is the X-axis coordinate value of the reference point, C2 is the Z-axis coordinate value of the reference point, and L is the vertical distance from the center point of the inner ring (501) of the knuckle bearing to the origin of coordinates; And respectively carrying out differential operation on dynamic change functions C1 (t) and C2 (t) of the reference point coordinates to obtain the change relation of displacement control amounts of the first linear module (201) and the second linear module (202) along with time, converting the change relation into an electric signal control instruction, driving the first linear module (201) and the second linear module (202) to complete corresponding linear movement, and further driving the inner ring (501) to realize compound deflection movement through the swinging rod (205).
10. The method for testing the comprehensive fatigue life of the high-temperature environment of the spherical plain bearing according to claim 6, wherein in the step S6, the performance detection comprises visual inspection, fluorescent flaw detection and radial play measurement; the judging standard is that when visual inspection is carried out, no hidden crack exists in fluorescent flaw detection, the radial clearance is in a qualified range, the fatigue life of the joint bearing to be tested under the current test working condition is judged to be qualified, and when any detection item is not qualified, the fatigue life is judged to be unqualified.

Description

Joint bearing high-temperature environment comprehensive fatigue life testing device and testing method Technical Field The invention belongs to the technical field of joint bearing comprehensive performance test, and particularly relates to a joint bearing high-temperature environment comprehensive fatigue life test device and a joint bearing high-temperature environment comprehensive fatigue life test method. Background The knuckle bearing is used as a special sliding bearing, has strong bearing capacity, good self-aligning performance and can bear multidirectional load, and is widely applied to the key fields of aerospace, rail transit, metallurgical equipment, high-end special robots and the like. During actual service, the knuckle bearing may be in an extremely harsh working environment. For example, in the working joints of aircraft deicing robots, the bearings need to be flexibly deflected under the conditions of high-temperature deicing fluid circulation and hot air, in the vector nozzle adjusting mechanism of an aircraft engine, the joint bearings are exposed to the high-temperature environment near the high-temperature tail gas flow and bear the heavy duty of changing the thrust direction at high frequency, and in large metallurgical machinery, the joints of the tapping manipulators need to bear heavy-duty alternating pressure at the high temperature of molten radiation. These conditions require that the knuckle bearing not only withstand high tensile loads, but also undergo frequent and complex angular adjustment movements with the action of the mechanical structure. Under a continuous high-temperature environment, the thermal stability, oxidation resistance and dynamic friction behavior of the material are deeply interwoven, and the reliability and fatigue life of the bearing are determined together. At present, performance evaluation means for the knuckle bearing focus on testing under a single working condition or a simplified working condition. For example, common testing machines are mainly tested for static tensile load capacity of bearings, or simply motion simulation fatigue tests in room temperature environments. However, the knuckle bearing in practical engineering applications may be subjected to high frequency alternating impact loads and its spatially-skewed pose has non-linear and complex characteristics. Because the joint bearing has a compact internal structure, high-frequency alternating load, three-dimensional composite attitude and hundreds of degrees of high-temperature environment are integrated in a limited space range, and extremely high requirements on mechanical decoupling precision, dynamic control capability and reliability design of a test system are provided. If the axial force loading, the multi-degree-of-freedom swinging and the high-temperature control system are subjected to simple hardware superposition, not only is the motion interference among mechanical structures easily generated, but also complex solving burden is easily caused, and the reliability of test data can be influenced by the mutual interference among physical fields. Therefore, how to construct a comprehensive test platform capable of deeply restoring the high coupling characteristics of the variable load, multi-pose and thermal working condition of the joint bearing becomes a key technical problem for restricting research, development, evaluation and life prediction of the high-performance joint bearing. Disclosure of Invention Aiming at the defects existing in the prior art, the invention provides a device and a method for testing the comprehensive fatigue life of a joint bearing in a high-temperature environment. The invention aims to solve the technical problems that mechanical interference is easy to generate, control resolving is complex and the coupling simulation degree of multiple physical fields is low when high-dimensional motion and extreme environments are integrated in a limited space, and is a comprehensive performance test scheme capable of realizing the dynamic alternating load, the composite deflection gesture and the high-temperature working condition of a joint bearing. The invention provides a joint bearing high-temperature environment comprehensive fatigue life testing device which comprises an axial force application assembly, a bearing loading assembly, a deflection assembly and a deflection assembly, wherein the axial force application assembly is used for providing controlled axial stretching or compression load for a joint bearing to be tested, the bearing loading assembly is connected with the axial force application assembly and comprises a deflection bracket and a pitching bracket which are mutually nested and in linkage fit, the deflection bracket and the pitching bracket are used for fixing the joint bearing to be tested and providing horizontal deflection and pitching motion compound degrees of freedom for the joint bearing to be tested, the deflection application