CN218938075U

CN218938075U - Device for electrolytic corrosion test of rolling bearing

Info

Publication number: CN218938075U
Application number: CN202222125324.0U
Authority: CN
Inventors: 陈升儒; 李自颖; 连杰; 王永臣
Original assignee: Qingdao Runde Precision Bearing Manufacturing Co ltd; QINGDAO TAIDE AUTOMOBILE BEARING CO Ltd
Current assignee: Qingdao Runde Precision Bearing Manufacturing Co ltd; Qingdao Tede Bearing Technology Co ltd
Priority date: 2022-08-12
Filing date: 2022-08-12
Publication date: 2023-04-28
Anticipated expiration: 2032-08-12

Abstract

The utility model discloses a device for an electroerosion test of a rolling bearing, which comprises a frame, wherein a sleeve is fixedly arranged on the frame along the vertical direction, a main shaft capable of rotating axially is arranged along the axis of the sleeve, and a back nut, an upper supporting bearing, an annular sliding block, a tested bearing, a test sliding seat, an annular force transducer, a compression spring and a lower supporting bearing are sleeved in sequence from top to bottom along the main shaft; an electric signal measuring unit is also arranged on the frame, and an electric corrosion detection closed loop is formed between the electric signal measuring unit and the tested bearing as well as between the electric signal measuring unit and the main shaft. The device uses the thrust ball bearing as a test bearing, is easy to disassemble and assemble, can stop at any time in the test process, and can disassemble, observe, analyze and measure the electrolytic corrosion condition of the channel and the steel ball, and study the electrolytic corrosion mechanism of the bearing; the test device can test the electric erosion parameters of the bearing under different rotating speeds, loads, temperatures and current intensities respectively, can test in a short time under a single parameter, greatly improves the data acquisition rate, and is convenient for analyzing test results.

Description

Device for electrolytic corrosion test of rolling bearing

Technical Field

The utility model belongs to the technical field of bearing test equipment, and particularly relates to a device for a rolling bearing electric erosion test.

Background

Rolling bearings are a very common component of machine equipment, and in general, rolling bearings are mainly damaged in three modes of forceful damage, thermal damage and electrical damage. For motor bearings, electrical damage is the predominant form of damage, namely bearing galvanic corrosion damage. Bearing electric corrosion refers to the phenomenon that when current flows in contact parts of inner and outer raceways of a bearing and rolling bodies in rotation, a lubricating oil film is broken down to generate spark discharge, so that the metal surface is damaged. Grease forms a lubricating film between the inner and outer rings of the bearing and the rolling elements, typically having a very thin film thickness (0.1 to 1 micron), and when an electric current is generated and exceeds the threshold voltage of the film, the bearing current breaks down the film, causing damage to the rolling elements and the raceway surfaces. Such damage is known as a streak or partially melted pit called a ridge mark, which causes vibration and noise and leads to a reduction in the service life of the bearing. In addition, the problem of grease deterioration is also caused. Thus, research into bearing galvanic corrosion has become indispensable.

The existence of electric corrosion in rolling bearings in electric motors has been a phenomenon known for a long time, but has not been sufficiently emphasized, and in recent years, due to the rapid development of electric vehicles, particularly as the continuous speed control of electric motors is increasingly performed using frequency converters in modern power transmission systems, the problem of bearing electric corrosion will become more and more pronounced in the future, and the trend of using higher voltages in electric vehicle power systems will lead to higher energy discharges. The popularization of the variable frequency speed regulation technology frequently causes bearing electric erosion.

The research on the reliability of the motor shows that the damage of the motor caused by the damage of the motor bearing accounts for 40% of the total damage, and 25% of the damage of the motor bearing is caused by dv/dt of the PWM inverter, and the number is increasing at a striking speed along with the wide use of high-performance devices such as IGBT, and the like, so the problem has become a hot spot of research at home and abroad. Studies have shown that the damage to the motor bearings under the power supplied by PWM inverters is due to the generation of so-called "shaft voltage" which is the voltage value of the rotor shaft to the stator, and "bearing current", which is formed by the current generated by the voltage through the bearings.

Existing devices that simulate a bearing to produce bearing currents are mostly used to study the durability test of the bearing in an electrically conductive condition. However, the electric corrosion mechanism of the bearing is less researched, and the influence rule of different current densities on the electric corrosion damage process of the bearing and the performance degradation of the lubricating grease is less researched.

Disclosure of Invention

Aiming at the defects of the prior art, the utility model provides a novel device for testing and researching the electrolytic corrosion characteristics of the rolling bearing. In order to achieve the technical purpose, the utility model adopts the following technical scheme:

the utility model provides a dress for antifriction bearing electric erosion test, includes the frame, is equipped with cylindrical sleeve along vertical direction fixedly on the frame, is equipped with the main shaft that can axial rotation along sleeve axis, is equipped with back nut, upper support bearing, annular slider, test bearing, test slide, annular force transducer, compression spring and lower support bearing along main shaft from top to bottom in proper order; the outer diameter of the back nut is in threaded fit with the inner wall of the sleeve, and the inner wall of the back nut is not contacted with the surface of the main shaft; the upper support bearing and the test sliding seat can slide up and down along the inner wall of the sleeve, and the annular sliding block can slide up and down along the main shaft and synchronously rotate with the main shaft; the lower support bearing is fixedly arranged on the frame and used for supporting the main shaft, and the lower end of the compression spring is pressed on the frame; the upper end face of the test sliding seat is provided with an annular metal plate, the tested bearing is a thrust ball bearing, and the lower surface of the tested bearing is pressed on the annular metal plate; the machine frame is also provided with an electric signal measuring unit, the electric signal measuring unit comprises a direct current power supply, the upper end of the sleeve is provided with a conductive carbon brush which is contacted with the surface of the main shaft, the electric signal measuring unit is respectively connected with the annular metal plate and the conductive carbon brush through a wire, the direct current output by the electric signal measuring unit passes through the annular metal plate, the tested bearing, the main shaft and the conductive carbon brush and returns to the electric signal measuring unit to form a series closed loop, and an adjustable resistor is arranged on the loop circuit.

Preferably, the spindle is driven to rotate by a motor provided on the frame through a v-ribbed belt.

Preferably, the tested bearing is of a separation structure and comprises a shaft collar, a seat ring, a steel ball and a retainer, wherein the inner diameter of the shaft collar is in contact fit with the surface of the main shaft, the inner diameter of the seat ring is not in contact with the surface of the main shaft, and the lower surface of the seat ring is pressed on the annular metal plate.

Preferably, a temperature sensor is arranged on the test sliding seat, and the probe of the temperature sensor is contacted with the seat ring.

Further, a miniature air pump is arranged on the sleeve.

Preferably, mutually matched splines are arranged between the surface of the main shaft and the inner diameter of the annular sliding block along the vertical direction.

Preferably, a first bearing seat is arranged between the upper support bearing and the inner wall of the sleeve, and the first bearing seat is made of insulating materials.

Further, the outer peripheral surface of the first bearing seat is provided with a vertical groove and is fixed by a set screw with a pin penetrating through the sleeve.

Preferably, the outer peripheral surface of the test sliding seat is provided with a vertical groove and is fixed by a set screw with a pin penetrating through the sleeve, and the bottom of the test sliding seat is provided with an oil seal.

Preferably, the lower support bearing is fixedly arranged on the frame through the second bearing seat, a step part which is supported on the lower support bearing is arranged at the position, close to the lower end, of the main shaft, the lower section of the main shaft is matched with the inner ring of the lower support bearing, and an insulating sleeve is arranged between the outer circumferential surface of the lower support bearing and the second bearing seat.

Compared with the prior art, the utility model has the beneficial effects that: the thrust ball bearing is used as a test bearing, so that the thrust ball bearing is easy to disassemble and assemble, the change of bearing voltage can be monitored in real time, test load, current or voltage can be set before the test is started, the test can be stopped at any time, the analysis and measurement of the electrolytic corrosion condition of the channel and the steel ball can be disassembled, the damage to the bearing can be avoided, the test can be continued after the reassembly, the electrolytic corrosion process of the bearing in the test process can be conveniently observed, and the electrolytic corrosion mechanism of the bearing can be researched; the method can test the electrolytic corrosion parameters of the bearing under different rotating speeds, loads, temperatures and current intensities respectively, so that the failure analysis of the lubricating grease is facilitated; short-time testing, such as minutes to hours, can be performed under a single parameter, and the change of the electrical signal during the testing process is recorded at a higher data acquisition rate, so that analysis of the test results is facilitated.

Drawings

Fig. 1: the general cross-sectional structure of the present utility model is schematically shown.

Fig. 2: the side view structure of the utility model is schematically shown.

Fig. 3: the upper half of the utility model is schematically shown in cross-section.

Fig. 4: the lower half of the utility model is schematically shown in cross-section.

Fig. 5: the utility model discloses a three-dimensional structure schematic diagram of a ring-shaped sliding block and a main shaft.

Fig. 6: the cross-sectional structure of the tested bearing is shown schematically.

In each figure:

1. a frame; 101. a motor; 102. a V-ribbed belt; 2. a sleeve; 21. a micro air pump; 3. a main shaft; 4. a back nut; 5. an upper support bearing; 51. a first bearing seat; 6. an annular slide block; 7. a tested bearing; 71. a shaft collar; 72. a seat ring; 73. a steel ball; 74. a retainer; 8. testing a sliding seat; 81. an annular metal plate; 82. an oil seal; 83. a temperature sensor; 9. a ring-shaped load cell; 10. a compression spring; 11. a lower support bearing; 111. a second bearing seat; 112. an insulating sleeve; 12. an electric signal measurement unit; 121. a direct current power supply; 122. a conductive carbon brush; 123. and the resistance can be adjusted.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the utility model. The terms such as "upper", "lower", "left", "right", "middle" and the like are also used in the present specification for convenience of description, and are not intended to limit the scope of the present utility model, but rather to change or adjust the relative relationship thereof, without substantially changing the technical content, and are considered to be within the scope of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The device for the electrolytic corrosion test of the rolling bearing, referring to fig. 1 to 4, comprises a frame 1, wherein a cylindrical sleeve 2 is fixedly arranged on the frame 1 along the vertical direction, a main shaft 3 capable of rotating axially is arranged along the axis of the sleeve 2, and the rotation of the main shaft 3 can be driven by a motor 101 arranged on the frame 1 through a V-ribbed belt 102; a back nut 4, an upper supporting bearing 5, an annular sliding block 6, a tested bearing 7, a test sliding seat 8, an annular force transducer 9, a compression spring 10 and a lower supporting bearing 11 are sleeved in sequence from top to bottom along the main shaft 3; the external diameter of the back nut 4 is in threaded fit with the inner wall of the sleeve 2, the inner wall of the back nut 4 is not in contact with the surface of the main shaft 3, the upper support bearing 5 and the test sliding seat 8 can slide up and down along the inner wall of the sleeve 2, the annular sliding block 6 can slide up and down along the main shaft 3 and rotate synchronously with the main shaft 3, and in a specific structure, as shown in fig. 5, mutually matched splines are arranged between the surface of the main shaft 3 and the internal diameter of the annular sliding block 6 along the vertical direction. The lower support bearing 11 is fixedly arranged on the frame 1 and supports the main shaft 3, and the lower end of the compression spring 10 is pressed on the frame 1. In a specific structure, a step part is arranged at the position, close to the lower end, of the main shaft 3, the lower part of the step part is matched with the inner ring of the lower support bearing 11, the step surface is supported on the lower support bearing 11, and the main shaft 3 is limited downwards through the lower support bearing 11. The upper support bearing 5 and the lower support bearing 11 act together to limit the spindle 3 in the axial direction, so that the spindle 3 is ensured to be stable in the axial direction during rotation. The upper end face of the test sliding seat 8 is provided with an annular metal plate 81, the tested bearing 7 is a thrust ball bearing, and the lower surface of the tested bearing 7 is pressed on the annular metal plate 81. Specifically, the tested bearing 7 is in a separable structure, and referring to fig. 6, the tested bearing 7 includes a shaft collar 71, a race 72, a steel ball 73 and a retainer 74, the inner diameter of the shaft collar 71 is in contact fit with the surface of the main shaft 3, the inner diameter of the race 72 is not in contact with the surface of the main shaft 3, and the lower surface of the race 72 is in contact with an annular metal plate 81. The machine frame 1 is further provided with an electric signal measuring unit 12, the electric signal measuring unit 12 comprises a direct current power supply 121, the upper end of the sleeve 2 is provided with a conductive carbon brush 122 contacted with the surface of the main shaft 3, the electric signal measuring unit 12 is respectively connected with the annular metal plate 81 and the conductive carbon brush 122 through wires, direct current output by the electric signal measuring unit 12 passes through the annular metal plate 81, the tested bearing 7, the main shaft 3 and the conductive carbon brush 122 and returns to the electric signal measuring unit 12 to form a series closed loop, and an adjustable resistor 123 is arranged on a loop line. The setting of the output electric signal can be carried out through the direct current power supply 121, and the regulation of the loop electric signal can be carried out through the adjustable resistor 123, so that the current and voltage working condition of the bearing can be simulated more flexibly, and the electric signal measuring unit 12, the direct current power supply 121 and the adjustable resistor 123 used in the device are all common instruments and equipment in the prior art, so that the specific description is omitted.

The working process and principle of the device are as follows: firstly, the main shaft 3 is installed on the frame 1 through the lower support bearing 11, insulation of the upper end part of the main shaft 3 is made, the compression spring 10 and the annular force transducer 9 are sequentially installed on the main shaft 3, the tested bearing 7 is installed on the test sliding seat 8 which is provided with the annular metal plate 81, then the test sliding seat 8 and the tested bearing 7 are installed on the main shaft 3, the connection terminal and the wire are connected at the annular metal plate 81 in advance, then the annular sliding block 6 and the upper support bearing 5 are sequentially installed on the main shaft 3, and the main shaft unit installation is completed. Then the main shaft unit is sleeved and fixed on the frame 1 by the sleeve 2, the upper support bearing 5 and the test sliding seat 8 are matched with the inner wall of the sleeve 3 and can slide up and down along the inner wall of the sleeve 3, in a preferred embodiment, as shown by referring to FIG. 3, a first bearing seat 51 made of insulating material is arranged between the upper support bearing 5 and the inner wall of the sleeve 2, the outer peripheral surface of the first bearing seat 51 is provided with a vertical groove, and the first bearing seat is fixed by a set screw with a pin penetrating through the sleeve 2; the outer peripheral surface of the test sliding seat 8 is also provided with a vertical groove, the vertical groove is fixed by a set screw with a pin penetrating through the sleeve 2, the angle is adjusted when the upper support bearing 5 and the test sliding seat 8 are installed on the main shaft 3, the vertical groove corresponds to the position of the set screw with the pin, after the sleeve 2 is installed, the upper support bearing 5 and the test sliding seat 8 can slide up and down along the inner wall of the sleeve 2, and the rotation cannot occur in the circumferential direction. To prevent grease leakage and contamination in the test bearings 7, an oil seal 82 may be provided at the bottom of the test carriage 8. One side of the sleeve 2 is provided with a vertical opening for the extraction of the wires connected to the annular metal plate 81. A back nut 4 is installed above the main shaft 3, and a conductive carbon brush 122 and a wire are connected. After the sleeve 2 is mounted, wires connected to the annular metal plate 81 and the conductive carbon brush 122 are connected to the output and input ends of the electric signal measuring unit 12, respectively, and an adjustable resistor 123 is connected in series to the wires. After the electric signal measuring unit 12 and the adjustable resistor 123 are adjusted to a test state, the back nut 4 is rotated downwards, the load of the tested bearing 7 is loaded by the back nut 4 matched with the compression spring 10, when the back nut 4 is rotated downwards, pressure is applied to the annular sliding block 6 matched with the main shaft 3 through the spline, the pressure is transferred to the tested bearing 7 through the annular sliding block 6, the test bearing 7 is tightly pressed on the test sliding seat 8, the load is transferred downwards by the test sliding seat 8 to the annular force transducer 9, the applied load is buffered by the compression spring 10 below, and the change of the pressure value on the display screen connected with the annular force transducer 9 is observed, so that the aim of applying the preset load to the tested bearing 7 is fulfilled. The switch of the electric signal measuring unit 12 is turned on, the electric signal is sent out by the direct current power supply 121, and returns to the electric signal measuring unit 12 after passing through the annular metal plate 81, the seat ring 72 of the tested bearing 7, the steel ball 73, the shaft ring 71, the main shaft 3, the conductive carbon brush 122 and the adjustable resistor 123 to form a closed loop. Simultaneously, the spindle 3 starts to rotate under the drive of the motor 101, and the rotating speed can be displayed and controlled in real time through a controller connected with the motor 101. The tested bearing 7 is placed under the annular sliding block 6, during experiments, the axial downward force along the main shaft 3 is applied through the back nut 4, so that the annular sliding block 6 is tightly contacted with the shaft collar 71 of the tested bearing 7, when the main shaft 3 drives the annular sliding block 6 to synchronously rotate, the annular sliding block 6 drives the shaft collar 71 of the tested bearing 7 to rotate, meanwhile, the seat ring 72 is tightly pressed on the annular metal plate 81, and the test sliding seat 8 is limited by the pin set screw and can only move up and down without rotating, so that the rotating speed of the main shaft 3 is the relative rotating speed between the shaft collar 71 of the tested bearing 7 and the seat ring 72. In the test process, the change of the signal is observed at any time, when the characteristic electric signal related to bearing electric corrosion is monitored, the test can be stopped at any time, the tested bearing 7 is taken down, the channel of the tested bearing 7, the surface condition of the steel ball 73 and the state of lubricating grease are observed, and then the test is reassembled and continued.

In a preferred embodiment, the test slide 8 is provided with a temperature sensor 83, and the probe of the temperature sensor 83 is in contact with the seat ring 72 and is used for monitoring the temperature of the tested bearing 7, and the sleeve 2 is provided with a micro air pump 21, so that the aim of controlling and adjusting the temperature of the test environment in the sleeve 2 is fulfilled through air circulation and cooling.

In order to better ensure the closure of the galvanic test circuit, so that the current does not conduct out from the sleeve 2 and the frame 1, the device is reasonably insulated. The main shaft 3 can effectively stop electric conduction between the main shaft 3 and the frame 1 by driving rotation of the V-ribbed belt 12, the inner diameter of the back nut 4 is not contacted with the surface of the main shaft 3, the first bearing seat 51 between the upper support bearing 5 and the sleeve 2 is made of insulating materials, the inner diameter of the shaft collar 71 of the tested bearing 7 is contacted and matched with the surface of the main shaft 3, the inner diameter of the seat ring 72 is not contacted with the surface of the main shaft 3, the test sliding seat 8 is made of insulating materials, the seat ring 72 is connected with an external circuit by an annular metal plate 81 on the test sliding seat 8, the lower support bearing 11 is fixedly arranged on the frame 1 by the second bearing seat 111, and an insulating sleeve 112 is arranged between the outer circumferential surface of the lower support bearing 11 and the second bearing seat 111.

Compared with the prior art, the device adopts the thrust ball bearing as the test bearing 7, is easy to disassemble and assemble, can monitor the change of bearing voltage in real time, can set test load, current or voltage before the test starts, can stop at any time in the test process, and can disassemble, observe, analyze and measure the electrolytic corrosion condition of the channel and the steel ball, the disassembly can not damage the bearing, the test is continued after the reassembly, the electrolytic corrosion process of the bearing in the test process is conveniently observed, and the electrolytic corrosion mechanism of the bearing is researched; the method can test the electrolytic corrosion parameters of the bearing under different rotating speeds, loads, temperatures and current intensities respectively, so that the failure analysis of the lubricating grease is facilitated; short-time testing, such as minutes to hours, can be performed under a single parameter, and the change of the electrical signal during the testing process is recorded at a higher data acquisition rate, so that analysis of the test results is facilitated.

In conclusion, the device for the rolling bearing electric erosion test effectively solves the problems that the prior art lacks means for detecting the bearing electric erosion characteristics under different conditions of current, load, rotating speed, temperature and the like and the test data acquisition rate is low, has high utilization value and use meaning, and can be widely popularized and applied.

While the foregoing is directed to the preferred embodiments of the present utility model, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present utility model, and such modifications and adaptations are intended to be comprehended within the scope of the present utility model.

Claims

1. Device for the galvanic corrosion testing of rolling bearings, comprising a frame (1), characterized in that:

a cylindrical sleeve (2) is fixedly arranged on the frame (1) along the vertical direction, a main shaft (3) capable of rotating axially is arranged along the axis of the sleeve (2), and a back nut (4), an upper support bearing (5), an annular sliding block (6), a tested bearing (7), a test sliding seat (8), an annular force transducer (9), a compression spring (10) and a lower support bearing (11) are sleeved in sequence from top to bottom along the main shaft (3); the outer diameter of the back nut (4) is in threaded fit with the inner wall of the sleeve (2), and the inner wall of the back nut (4) is not contacted with the surface of the main shaft (3); the upper support bearing (5) and the test sliding seat (8) can slide up and down along the inner wall of the sleeve (2), and the annular sliding block (6) can slide up and down along the main shaft (3) and rotate synchronously with the main shaft (3); the lower support bearing (11) is fixedly arranged on the frame (1) and supports the main shaft (3); the lower end of the compression spring (10) is pressed on the frame (1); an annular metal plate (81) is arranged on the upper end face of the test sliding seat (8), the tested bearing (7) is a thrust ball bearing, and the lower surface of the tested bearing (7) is pressed on the annular metal plate (81);

still be equipped with electric signal measurement unit (12) on frame (1), electric signal measurement unit (12) include DC power supply (121), sleeve (2) upper end be equipped with electric conductive carbon brush (122) that main shaft (3) surface contacted, electric signal measurement unit (12) pass through the wire with annular metal sheet (81) and electric conductive carbon brush (122) are connected respectively, by the direct current of electric signal measurement unit (12) output is through annular metal sheet (81) test bearing (7) main shaft (3) with electric conductive carbon brush (122) and return electric signal measurement unit (12) form the closed loop of series connection, are equipped with adjustable resistance (123) on the return circuit.

2. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: the main shaft (3) is driven to rotate by a motor (101) arranged on the frame (1) through a V-ribbed belt (102).

3. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: the tested bearing (7) is of a separable structure and comprises a shaft collar (71), a seat ring (72), a steel ball (73) and a retainer (74), wherein the inner diameter of the shaft collar (71) is in contact fit with the surface of the main shaft (3), the inner diameter of the seat ring (72) is not in contact with the surface of the main shaft (3), and the lower surface of the seat ring (72) is pressed on the annular metal plate (81).

4. A device for a rolling bearing galvanic test according to claim 3, wherein: the test slide seat (8) is provided with a temperature sensor (83), and the probe of the temperature sensor (83) is contacted with the seat ring (72).

5. An apparatus for a rolling bearing electric corrosion test as set forth in claim 4, wherein: the sleeve (2) is provided with a miniature air pump (21).

6. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: and mutually matched splines are arranged between the surface of the main shaft (3) and the inner diameter of the annular sliding block (6) along the vertical direction.

7. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: a first bearing seat (51) is arranged between the upper support bearing (5) and the inner wall of the sleeve (2), and the first bearing seat (51) is made of an insulating material.

8. An apparatus for a rolling bearing electric corrosion test according to claim 7, wherein: the outer peripheral surface of the first bearing seat (51) is provided with a vertical groove and is fixed by a set screw with a pin penetrating through the sleeve (2).

9. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: the outer peripheral surface of the test sliding seat (8) is provided with a vertical groove and is fixed through a set screw with a pin penetrating through the sleeve (2), and the bottom of the test sliding seat (8) is provided with an oil seal (82).

10. An apparatus for a rolling bearing electrical erosion test as in claim 1, wherein: the lower support bearing (11) is fixedly mounted on the frame (1) through a second bearing (111), a step part for supporting the lower support bearing (11) is arranged at the position, close to the lower end, of the main shaft (3), the lower section of the main shaft (3) is matched with the inner ring of the lower support bearing (11), and an insulating sleeve (112) is arranged between the outer circumferential surface of the lower support bearing (11) and the second bearing (111).