An integrated machine for measuring roller wear, fatigue and life under complex working conditions

Abstract

The present invention relates to an integrated machine for measuring roller wear and fatigue life under complex working conditions, and belongs to the field of mechanical design and manufacturing. It includes a test core component, a loading system, a transmission system, and a data acquisition system; the test core component is a core mechanism for realizing four-line contact testing of the test roller, and the oil tank supplies oil and lubrication to the test core component; the electric cylinder is installed on the upper part of the upper bracket and connected to the test core component to realize test loading; the motor is connected to drive the test core component through the transmission mechanism to realize roller wear fatigue life testing under complex working conditions. The present invention can test four-line equal load contact, and can realize the test of wear life and fatigue life of bearing rollers of different sizes and different materials under different speeds, different loads, and different lubricating oil working conditions, providing a reliable basis for the wear failure of bearing rollers affected by factors such as material properties, manufacturing processes, geometric properties, and specific working conditions, better analyzing the failure causes of bearing rollers, and improving the reliability of their service life.

Description

Technical Field

[0001] The invention relates to a roller wear fatigue life integrated machine under complex working conditions, belonging to the field of mechanical design and manufacturing. Background Art

[0002] Bearing rollers are a highly reliable, foundational component widely used in modern machinery. Under standard operating conditions, friction between contacting surfaces during relative sliding causes continuous surface material loss, residual deformation, or fracture, a phenomenon known as wear failure. Fatigue failure also occurs when cyclic contact forces between the friction surfaces cause surface material to flake off due to fatigue. Therefore, the wear and fatigue life of bearing rollers are important indicators for comprehensively evaluating the quality of bearing roller materials, structural design, manufacturing process, surface hardness, and lubrication.

[0003] Conducting a wear fatigue life test on bearing rollers alone can eliminate the mutual influence of many factors within the bearing, reliably verify the wear fatigue life of the rollers, and provide a reliable test basis for studying the wear fatigue failure mechanism of factors such as bearing roller material properties, manufacturing process, geometric optimization design, and specific working conditions, so as to better analyze the causes of bearing roller failure and improve the reliability of its service life.

[0004] Currently, there are many types of testing machines that are used solely to study the wear fatigue life performance of bearing rollers: Patent CN102147341A, a bearing roller contact fatigue testing machine, is mainly used to perform rolling contact fatigue life tests on standard short cylindrical rollers and rollers with convex rolling surfaces. During the rolling process, the rollers use a three-line contact method. Since the gear train structure only has one drive motor driving the active wheel, and the rest of the gear train is driven, it is inevitable that the driven wheel will slip and the pure rolling condition of the roller cannot be guaranteed. Patent CN106855480A, a dual-axis loaded four-line contact pure rolling cylindrical roller fatigue life testing machine, is mainly used for cylindrical roller fatigue life test research. This device uses pure rolling contact with four-line contact rollers that are subjected to four identical uniformly distributed line loads per rotation to achieve the effect of accelerated fatigue testing of the rollers. However, this testing machine can only perform pure rolling tests and cannot set the slip-roll ratio, and the test conditions are single. Patent CN108426795A, the invention of a high-speed rolling contact fatigue wear test bench can achieve different sliding-rolling ratios. However, it is only single-line contact fatigue, and the test time will be relatively long.

[0005] In summary, existing wear and fatigue life testing machines cannot simultaneously meet the needs of wear life and fatigue life testing under special working conditions. Therefore, it is very meaningful to develop an integrated roller wear and fatigue life testing machine under complex working conditions to study the wear and fatigue life performance of bearing rollers. Summary of the Invention

[0006] To achieve the above objectives, the present invention comprises the following: four test rollers of equal size are symmetrically distributed around the test roller, with the test roller positioned at the geometric center of the four test rollers. A load is applied vertically to the upper cover of the housing via an electric cylinder. The load is then transferred to the test roller via the loading wheel, acting on the test rollers. The test roller is subjected to force along the generatrix, with the load acting four times per rotation. A motor drives the loading shaft and the support shaft respectively via a main synchronous belt. Dual synchronous pulleys drive the two drive shafts, ensuring that the rotational speeds of the two drive shafts are equal to those of the loading shaft and the support shaft, respectively. A speed sensor measures the speed of the motor output shaft, converts this speed into the speed of the test roller, and calculates the number of stress cycles of the test roller. A pressure sensor monitors the applied load in real time. Pressure data and test roller dimensional data are input into a system and converted into the maximum contact stress of the test roller. An acceleration sensor is mounted above the loading shaft to measure the vibration signal of the testing machine. A temperature sensor measures the temperature of the lubricant ejected by the test roller. A displacement sensor is mounted directly above the loading shaft to measure the vertical displacement of the loading shaft to estimate the wear of the test roller. When fatigue failure occurs in the test roller or related rolling element, the vibration value and temperature rise value will increase. When the vibration value increases to the predetermined value, or the temperature rise reaches the set value, or the temperature rise gradient changes and maintains for a certain period of time, the test machine's measurement and control system will immediately terminate the test.

[0007] According to the above invention concept, the present invention adopts the following technical solutions:

[0008] An integrated machine for measuring roller wear and fatigue life under complex working conditions, comprising a machine base 6, a bracket 7, an oil tank 4, an oil pump 5, core test components, a loading system, a transmission system, and a data acquisition system;

[0009] The bracket 7 is fixed above the machine base 6; the oil tank 4 supplies oil lubrication to the test core components through the oil pump 5 and the pipeline; the test core components include a loading shaft 11, a support shaft 23, a test roller 26, two drive shafts 13 and four accompanying test rollers 25, all of which are located in the box body 24; the transmission system consists of two sets, each set includes a motor 3, an output shaft synchronous pulley 18, a main synchronous belt 16, a double synchronous pulley 12, a synchronous pulley 20 and a secondary synchronous belt 21; the loading system includes an electric cylinder 8 and a box body 24, and the box body 24 includes a box body upper cover 10 and a lower box body 17; the data acquisition system includes a speed sensor 15, a pressure sensor 9, a temperature sensor 19, an acceleration sensor 27 and a displacement sensor 22.

[0010] The ends of the loading shaft 11 and the support shaft 23 are respectively provided with double synchronous pulleys 12, and the ends of the two driving shafts 13 are respectively provided with synchronous pulleys 20; the double synchronous pulleys 12 on the loading shaft 11 and the synchronous pulley 20 on one driving shaft 13 are located at the front end of the roller wear fatigue life integrated machine under complex working conditions, and the double synchronous pulleys 12 on the support shaft 23 and the synchronous pulley 20 on the other driving shaft 13 are located at the rear end of the roller wear fatigue life integrated machine under complex working conditions; the loading shaft 11 is arranged below the upper cover 10 of the box body through a bearing, and the support shaft 23 and the two driving shafts 13 are arranged on the lower box body 17 through bearings, the loading shaft 11 and the support shaft 23 are on the same vertical line, the two driving shafts 13 are located between the support shaft 23 and the loading shaft 11, and on the same horizontal line, distributed on both sides above the support shaft 23; the positions of the support shaft 23 and the two driving shafts 13 are fixed, and the shaft edges are in line contact, and the loading shaft 11 can move up and down with the movement of the upper cover 10 of the box body. The four test rollers 25 are located in the central space formed by the loading shaft 11, the support shaft 23 and the two drive shafts 13, and the circular side surfaces of the test rollers 25 are in line contact with the axial edge surfaces of the loading shaft 11, the support shaft 23 and the two drive shafts 13; the test roller 26 is located in the central space formed by the four test rollers 25, and the circular side surfaces of the test roller 26 are in line contact with the axial edge surfaces of the four test rollers 25.

[0011] In each of the transmission systems, the output shaft synchronous pulley 18 on the motor 3 is connected to the double synchronous pulley 12 through the main synchronous belt 16, and the double synchronous pulley 12 is connected to the synchronous pulley 20 through the secondary synchronous belt 21; the double synchronous pulley 12 of one transmission system is mounted on the loading shaft 11, and the double synchronous pulley 12 of the other transmission system is mounted on the support shaft 23.

[0012] The electric cylinder 8 is arranged on the bracket 7, with the telescopic end facing downward and connected to the pressure sensor 9; the pressure sensor 9 is arranged on the box cover 10, and the box cover 10 can move up and down with the telescopic movement of the electric cylinder 8, thereby driving the loading shaft 11 to move up and down; the box 24 is arranged on the machine base 6 through the box base 14.

[0013] The pressure sensor 9 is installed directly above the upper cover 10 of the box to ensure the accuracy of the pressure data required for the test and to monitor the changes in the applied load during the test in real time; the speed sensor 15 is installed at the loading shaft 11 or the support shaft 23 to measure the rotation speed of the shaft, which is converted into the rotation speed of the test roller 26 and the number of stress cycles of the test roller 26; the temperature sensor 19 is installed at the oil throwing point of the test roller 26 to measure the changes in the lubricating oil temperature; the acceleration sensor 27 is installed above the loading shaft 11 to test the vibration frequency signal during the test; the displacement sensor 22 is installed directly above the loading shaft 11 to measure the vertical displacement of the loading shaft 11 to infer the wear of the test roller 26.

[0014] The motor base 1 is fixedly connected to one side of the machine base 6; the motor base plate 2 is mounted on the motor base 1 through a hinge; the motor 3 is fixedly connected to the motor base plate 2, and the upper and lower positions of the motor are adjusted by the motor adjusting bolts to ensure that the synchronous belt is tensioned.

[0015] The rotation speed sensor 15, the pressure sensor 9, the temperature sensor 19, the acceleration sensor 27 and the displacement sensor 22 are each connected to the computer through a conditioning circuit and an acquisition card.

[0016] The two ends of the four accompanying test rollers 25 and the test roller 26 need to be limited. Compared with the prior art, the present invention has obvious substantial features and advantages:

[0017] The present invention can perform wear and fatigue life tests on single bearing rollers; the axial lengths of the four main shafts are longer than the test rollers, so the test rollers are only subjected to force on the roller generatrix, and the test rollers are ensured to move along the circumference, which can more accurately test the actual bearing roller wear life and fatigue life; it can realize the test of the wear life and fatigue life of bearing rollers of different sizes and different materials under different speeds, different loads, and different lubricating oil working conditions, providing a reliable basis for the wear failure of the bearing rollers affected by factors such as material properties, manufacturing process, geometric properties, and specific working conditions, better analyzing the failure causes of the bearing rollers, and improving the reliability of their service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention.

[0019] Figure 2 It is a structural schematic diagram (front view) of the transmission system in the present invention.

[0020] Figure 3 It is a structural schematic diagram (rear view) of the transmission system in the present invention.

[0021] Figure 4 It is a structural diagram of the loading system in the present invention.

[0022] Figure 5 It is a radial cross-sectional view of the test core component in the present invention.

[0023] Figure 6 This is the structural block diagram of the data acquisition system.

[0024] Figure 7 This is the calculation and analysis diagram of the test roller wear.

[0025] In the figure: 1 motor base, 2 motor base plate, 3 motor, 4 oil tank, 5 oil pump, 6 machine base, 7 bracket, 8 electric cylinder, 9 pressure sensor, 10 box cover, 11 loading shaft, 12 double synchronous pulley, 13 drive shaft, 14 box base, 15 speed sensor, 16 main synchronous belt, 17 lower box, 18 output shaft synchronous pulley, 19 temperature sensor, 20 synchronous pulley, 21 secondary synchronous belt, 22 displacement sensor, 23 support shaft, 24 box, 25 test roller, 26 test roller, 27 speed sensor. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below with reference to the accompanying drawings:

[0027] See also Figure 1-Figure 5 The roller wear fatigue life integrated machine under complex working conditions includes a machine base 6, a bracket 7, an oil tank 4, an oil pump 5, test core components, a loading system, a transmission system and a data acquisition system;

[0028] The test core component is a core mechanism for implementing a four-line contact wear fatigue life test on the test roller, and is installed in the upper bracket 7; the oil tank 4 is connected to the test core component through the oil pump 5 and the pipeline to supply oil and lubrication to it; the electric cylinder 8 is installed on the upper part of the upper bracket 7 and connected to the test core component to realize test loading; the motor 3 is connected to drive the test core component through the transmission mechanism to realize roller wear fatigue life test under complex working conditions.

[0029] In the transmission system: the motor 3 drives the double synchronous pulley 12 through the main synchronous belt 16 to drive the loading shaft 11 (or support shaft 23), and then the secondary synchronous belt 21 drives the synchronous pulley 20 to drive the drive shaft 13, ensuring that the loading shaft 11 (or support shaft 23) and the drive shaft 13 rotate synchronously.

[0030] In the loading system, the load is loaded on the loading shaft 11 through the electric cylinder 8, and then applied to the test roller 25 through the loading shaft 11, and then transferred to the test roller 26; two motors 3 drive the loading shaft 11, the support shaft 23 and the two drive shafts 13 to rotate simultaneously through two main synchronous belts 16, and the four shafts drive the test roller 25 and indirectly drive the test roller 26; the core components of the test adopt the two drive shafts 13 on the same horizontal line, the loading shaft 11 and the support shaft 23 on the same vertical line, and the loading shaft 11 can move with the box cover 10, which can ensure that the centering of the test roller and the tested roller can be effectively adjusted when testing rollers of different sizes.

[0031] In the data acquisition system: the pressure sensor 9 is installed directly above the upper cover 10 of the box body to ensure the accuracy of the pressure data required for the test and to monitor the changes in the applied load during the test in real time; the speed sensor 15 is installed at the loading shaft 11 or the support shaft 23 to measure the rotation speed of the shaft, which is converted into the rotation speed of the test roller 26 and the number of stress cycles of the test roller 26; the temperature sensor 19 is installed at the oil throwing point of the test roller 26 to measure the change in the temperature of the lubricating oil; the acceleration sensor 27 is installed above the loading shaft 11 to test the vibration frequency signal during the test; the displacement sensor 22 is installed directly above the loading shaft 11 to measure the vertical displacement of the loading shaft 11 to infer the wear of the test roller 26. The speed sensor 15, pressure sensor 9, temperature sensor 19, acceleration sensor 27 and displacement sensor 22 are each connected to the computer through an acquisition card after passing through a conditioning circuit. (such as Figure 6 ).

[0032] This system mainly refers to two signal indicators for failure diagnosis. The first is temperature signal detection: by detecting the temperature at the injection point to determine whether the fatigue testing machine is working normally, temperature detection is more sensitive to changes in the load, speed and lubrication of the cylindrical roller. The second is vibration signal diagnosis: through the vibration signal collected by the acceleration sensor 27, the computer extracts the peak value, root mean square, kurtosis coefficient and other characteristic parameters of the vibration signal for time domain analysis, and uses FFT analysis, wavelet analysis and HHT analysis to perform frequency domain analysis on the vibration signal; the displacement sensor 22 is installed on the end horizontal plane of the electric cylinder 8 in the initial state of the extension and contraction end, and measures the extension and contraction length of the electric cylinder 8 to infer the wear of the test roller 26 (such as Figure 7 ).

[0033] (1) In the initial state, that is, in the vertical direction, the loading shaft 11 does not move. Let the straight line between the center of the loading shaft 11 and the center of a test roller 25 be L1, the straight line between the center of the loading shaft 11 and the center of the test roller 26 be L2, and the straight line between the center of the test roller 25 and the center of the test roller 26 be L3. Then the length d1 of the straight line L2 is:

[0034] d1=cosα1(r0+r2)+cosβ1(r2+r3)

[0035] Where α1 is the angle between the straight lines L2 and L3, β1 is the angle between the straight lines L1 and L2, r0 is the radius of the test roller, r2 is the radius of the companion test roller, and r3 is the radius of the loading shaft.

[0036] (2) When the testing machine is in operation, the test roller 26 wears due to long-term cycling, and its radius becomes r1. The wear of the loading shaft 11 and the accompanying test roller 25 is negligible compared to the wear of the test roller 26. At this time, the displacement sensor 22 measures the vertical displacement d2 of the loading shaft 11. The length d3 of the straight line L2 is:

[0037] d3=cosα2(r1+r2)+cosβ2(r2+r3)

[0038] Where α2 is the angle between the straight lines L2 and L3, β2 is the angle between the straight lines L1 and L2, r1 is the radius of the test roller after wear, r2 is the radius of the companion roller, and r3 is the radius of the loading shaft.

[0039] d2=2(d1-d3)

[0040] =2[cosα1(r0+r2)-cosα2(r1+r2)+(cosβ1-cosβ2)(r2+r3)]

[0041] The linear wear of the test roller can be calculated as:

[0042]

[0043] Conducting wear fatigue life testing on a single bearing roller (test roller 26) eliminates the interplay of numerous factors within the bearing, reliably verifying the wear fatigue life of the bearing roller. This provides a reliable test basis for studying the fatigue failure mechanisms of bearing rollers influenced by factors such as material properties, manufacturing processes, geometric optimization, and specific operating conditions. This allows for better analysis of the causes of bearing roller failure and improves the reliability of their service life. This testing machine can operate the bearing rollers at speeds of 0 to 4875 rpm, with contact loads up to 20 kN and contact stresses up to 4 GPa. By varying the load and speed, wear fatigue life testing of the bearing rollers can be performed under various operating conditions. During the test, vibration signals are measured online using an accelerometer 27, and the temperature rise of the test roller 26 is measured using a temperature sensor 19. When the test bearing roller fails, the system automatically shuts down after software analysis of the sudden change in vibration frequency output signal. The test can also be automatically terminated when the temperature rise reaches a certain threshold.

Claims

1. A roller wear fatigue life integrated machine under complex working conditions, characterized by: The roller wear fatigue life integrated machine under complex working conditions comprises a machine base (6), a bracket (7), an oil tank (4), an oil pump (5), a test core component, a loading system, a transmission system and a data acquisition system; The bracket (7) is fixed above the machine base (6); the oil tank (4) supplies oil lubrication to the test core components through the oil pump (5) and the pipeline; the test core components include a loading shaft (11), a support shaft (23), a test roller (26), two drive shafts (13) and four accompanying test rollers (25), all of which are located in the box (24); the transmission system is composed of two sets, each set including a motor (3), an output shaft synchronous pulley (18), a main synchronous belt (16), a double synchronous pulley (12), a synchronous pulley (20) and a secondary synchronous belt (21); the loading system includes an electric cylinder (8) and a box (24), and the box (24) includes a box cover (10) and a lower box (17); the data acquisition system includes a speed sensor (15), a pressure sensor (9), a temperature sensor (19), an acceleration sensor (27) and a displacement sensor (22); The ends of the loading shaft (11) and the supporting shaft (23) are respectively sleeved with double synchronous pulleys (12), and the ends of the two driving shafts (13) are respectively sleeved with synchronous pulleys (20); the double synchronous pulleys (12) on the loading shaft (11) and the synchronous pulley (20) on one driving shaft (13) are located at the front end of the roller wear fatigue life integrated machine under complex working conditions, and the double synchronous pulleys (12) on the supporting shaft (23) and the synchronous pulley (20) on the other driving shaft (13) are located at the rear end of the roller wear fatigue life integrated machine under complex working conditions; the loading shaft (11) is arranged below the upper cover (10) of the box body through a bearing, and the supporting shaft (23) and the two driving shafts (13) are arranged on the lower box body (17) through bearings, and the loading shaft (11) and the supporting shaft (23) are on the same vertical line, and the two The driving shaft (13) is located between the supporting shaft (23) and the loading shaft (11), and is located on the same horizontal line and distributed on both sides above the supporting shaft (23); the positions of the supporting shaft (23) and the two driving shafts (13) are fixed, and the shaft edges are in line contact with each other, and the loading shaft (11) can move up and down with the movement of the box cover (10); the four accompanying test rollers (25) are located in the central space formed by the loading shaft (11), the supporting shaft (23) and the two driving shafts (13), and the circular side surfaces of the accompanying test rollers (25) are in line contact with the shaft edges of the loading shaft (11), the supporting shaft (23) and the two driving shafts (13); the test roller (26) is located in the central space formed by the four accompanying test rollers (25), and the circular side surfaces of the test roller (26) are in line contact with the shaft edges of the four accompanying test rollers (25); In each transmission system, the output shaft synchronous pulley (18) on the motor (3) is connected to the double synchronous pulley (12) through the main synchronous belt (16), and the double synchronous pulley (12) is connected to the synchronous pulley (20) through the secondary synchronous belt (21); the double synchronous pulley (12) of one transmission system is sleeved on the loading shaft (11), and the double synchronous pulley (12) of the other transmission system is sleeved on the support shaft (23); The electric cylinder (8) is arranged on the bracket (7), with the telescopic end facing downward and connected to the pressure sensor (9); the pressure sensor (9) is arranged on the upper cover (10) of the box body, and the upper cover (10) of the box body can move up and down with the telescopic movement of the electric cylinder (8), thereby driving the loading shaft (11) to move up and down; the box body (24) is arranged on the machine base (6) through the box body base (14); The pressure sensor (9) is installed just above the upper cover (10) of the box body to ensure the accuracy of the pressure data required for the test and to monitor the changes in the applied load during the test in real time; the speed sensor (15) is installed at the loading shaft (11) or the support shaft (23) to measure the speed of the shaft, convert it into the speed of the test roller (26) and calculate the number of stress cycles of the test roller (26); the temperature sensor (19) is installed at the oil throwing part of the test roller (26) to measure the change in the temperature of the lubricating oil; the acceleration sensor (27) is installed above the loading shaft (11) to test the vibration frequency signal during the test; the displacement sensor (22) is installed just above the loading shaft (11) to measure the displacement of the loading shaft (11) in the vertical direction to infer the wear of the test roller (26).

2. The roller wear fatigue life integrated machine under complex working conditions according to claim 1, characterized in that: The motor base (1) is fixedly connected to one side of the machine base (6); the motor base plate (2) is mounted on the motor base (1) via a hinge; the motor (3) is fixedly connected to the motor base plate (2), and the upper and lower positions of the motor are adjusted via motor adjusting bolts to ensure that the synchronous belt is tensioned.

3. The roller wear fatigue life integrated machine under complex working conditions according to claim 1, characterized in that: The rotation speed sensor (15), the pressure sensor (9), the temperature sensor (19), the acceleration sensor (27) and the displacement sensor (22) are each connected to the computer via a data acquisition card after passing through a conditioning circuit.

4. The roller wear fatigue life integrated machine under complex working conditions according to claim 1, characterized in that: Both ends of the four accompanying test rollers (25) and the test roller (26) need to be limited.

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