Method for testing dynamic friction torque of precise bearing
By symmetrically installing test heads and sensors on the bearing outer race, directly measuring and recording the friction force of the bearing, the complexity and insufficient accuracy of the bearing dynamic friction torque test method in the existing technology is solved, and high-precision and convenient testing are achieved process.
Patent Information
- Application Number
- CN202411484747.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2024-12-13
AI Technical Summary
The existing bearing dynamic friction torque testing methods have problems such as complex structure, cumbersome operation and inability to measure accurately, especially the transmission method and energy conversion method have insufficient measurement accuracy and stability.
A precision bearing dynamic friction torque test method is adopted. By symmetrically installing test head A and test head B on the outer race of the bearing, the measurement point and the sensor are in contact with the friction force of the bearing act on the sensor through the measurement point, and the signal is output. Enter the computer data acquisition and processing system, and use a sensor to meet the testing needs of commonly used bearings, simplifying the testing process and improving accuracy.
More precise bearing deviation measurements and high-precision dynamic friction torque testing are achieved, simplifying the testing process, and the test data is directly available without additional conversion, improving the convenience and accuracy of measurement.
Smart Images
Figure CN119124422A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field, and in particular to a method for testing the dynamic friction torque of a precision bearing. Background Art
[0002] Bearings are an important component in modern mechanical equipment. Their main function is to support mechanical rotating bodies, reduce the friction coefficient during their movement, and ensure their rotation accuracy.
[0003] Bearings may seem simple, but they are the most widely used basic and key parts in various rotating equipment and mechanisms. According to historical statistics, more than 80% of the failures of moving parts and mechanisms are caused by bearing failures. Especially in some special occasions (such as space environments, continuously running production lines), bearings cannot be backed up, so once a bearing fails, it will affect the entire system and the consequences will be catastrophic.
[0004] In the past two decades, due to the problem of bearings, personnel at all levels have paid more and more attention to it. With the increasing requirements for the effectiveness of bearing quality control and performance evaluation, higher requirements have also been put forward for the previous evaluation indicators and methods.
[0005] For a long time, domestic bearing testing has been based on the static indicators of bearings and their components (inner and outer rings and balls) (such as size tolerance, shape tolerance, position tolerance and fit clearance between components, etc.) to evaluate bearings. However, static indicators cannot reflect the status under various operating conditions. Users need more dynamic indicators to understand the status of bearings during use and testing and make correct judgments.
[0006] The most basic, main and quantifiable indicator of bearing dynamic performance is friction torque, which reflects the power consumption and performance of bearing. The movement of bearing is a very complex process, which is mainly based on actual tests. First, the friction torque of single bearing is tested. Single bearing is the most basic single part. Only by starting with the most basic control can the use of bearing be effectively controlled.
[0007] The bearing friction torque is actually the rotational torque that hinders the operation of the bearing. According to its basic principle, in modern engineering, the commonly used methods for measuring the bearing friction torque can be divided into the transmission method, the balanced torque method and the energy conversion method.
[0008] 1. Transfer method
[0009] The transfer method is a method of measuring torque based on the changes in physical parameters such as strain, stress or rotation angle generated by an elastic element when transmitting torque.
[0010] When the driving bearing rotates, the existence of the bearing friction torque will cause torsional deformation of the driving shaft (torque transmission body). When the torque transmission body is composed of an elastomer or other shaft (sensor) that has a corresponding relationship with the torque, the torque size, i.e. the bearing friction torque, can be determined based on the change in physical parameters such as mechanical, hydraulic, pneumatic, resistance, capacitance, inductance, optics, photoelectricity, and magnetic resistance generated when the elastomer transmits the torque.
[0011] The structure of the transmission method generally includes: drive motor, angle sensor, precision measuring shaft system, friction torque sensor and positioning tire shaft and other components, and the structure is relatively complex.
[0012] The measuring shaft system is mainly used to transmit the friction torque of the measured shaft system, and to withstand the radial force generated by the small vibration caused by the imbalance, eccentricity, etc. during the rotation of the measured shaft system, so as to protect the torque sensor. Since the friction torque of the measuring shaft system is included in the measurement result, its friction torque directly affects the measurement error.
[0013] 2. Balanced moment method
[0014] The balanced torque method is a method of measuring friction torque by applying a balanced torque on the rotating shaft of the driving mechanism that is equal in magnitude and opposite in direction to the torque it is subjected to.
[0015] When the inner ring (outer ring) of the bearing rotates, there must be a friction torque on the outer ring (inner ring) of the bearing that hinders the rotation. This friction torque drives the outer ring (inner ring) to rotate, and a balancing torque (balancing force) equal to the friction torque and opposite in direction is applied to the outer ring (inner ring) of the bearing to hinder the rotation of the outer ring (inner ring) of the bearing. We only need to measure the size of the balancing torque (balancing force). This friction torque measurement method is called the balancing torque (balancing force) method.
[0016] The balanced force method is widely used in the measurement of dynamic friction torque of bearings because of its good measurement system stability, good dynamic frequency response, easy output signal acquisition and good anti-interference performance, and easy to achieve measurement conditions such as loading. However, it cannot be used to measure the starting friction torque.
[0017] 3. Energy conversion method
[0018] The method of measuring friction torque by converting energy into each other is called energy conversion method.
[0019] The bearing rotates under the drive of the torque generator (or motor) that drives its rotation. Part of the energy input to the torque generator becomes the kinetic energy of the bearing, and the other part becomes heat energy and other forms of energy consumed due to the existence of the bearing friction torque. The principle method of measuring the energy loss during the energy conversion process and indirectly measuring the bearing friction torque is defined as the energy conversion method measurement principle.
[0020] The torque generator (electromagnetic driver) drives the hollow cup rotor and the outer ring of the bearing to rotate, the speed sensor measures the speed of the hollow cup rotor, and the intelligent controller controls the input energy of the electromagnetic driver to keep the hollow cup at a constant speed, that is, to keep its kinetic energy unchanged.
[0021] There are three main methods for testing friction torque: transfer method, balance method and these three methods, but all of them have shortcomings. Among them, the energy conversion method uses the method of mutual conversion of energy to measure friction torque, which cannot accurately measure bearing friction torque. The basic principle of the other two methods is that the existence of bearing friction torque causes the torque transmission body to deform, and the change in mechanical, hydraulic, pneumatic, resistance, capacitance, inductance, optics, photoelectric, magnetic resistance and other physical parameters generated during torque deformation is used to determine the bearing friction torque. It is also an indirect test, and these methods require a drive motor, angle sensor, precision measurement shaft system, friction torque sensor, positioning tire shaft and other components. The structure is relatively complex and the operation is cumbersome.
[0022] Therefore, an improved bearing dynamic friction torque testing method is urgently needed to solve this problem existing in the prior art. Summary of the invention
[0023] The purpose of the present invention is to provide a device for installing a test bearing on a bearing adapter shaft of an equipment. When the main shaft rotates, the inner ring of the bearing is driven to rotate. A test head A and a test head B are symmetrically installed on the outer race of the bearing. During measurement, the measuring point contacts the sensor. During measurement, the measuring point on the inner race of the bearing contacts the sensor. After the friction force of the bearing acts on the sensor through the measuring point, it is converted into a corresponding electrical signal output through a secondary instrument. The output electrical signal is input into a computer data acquisition and processing system for recording. The dynamic friction torque test method of the bearing uses one sensor to meet the test range requirements of commonly used bearings. The test data can be used directly without conversion. It is convenient and has high test accuracy for the dynamic friction torque test method of precision bearings to solve the problems raised in the above background technology.
[0024] To achieve the above object, the present invention provides the following technical solution: a method for testing the dynamic friction torque of a precision bearing, wherein during the dynamic friction torque testing of the bearing:
[0025] Install the test bearing on the bearing adapter shaft of the equipment. When the main shaft rotates, the inner ring of the bearing will rotate.
[0026] Test heads A and B are symmetrically installed on the outer race of the bearing. During measurement, the measuring point is in contact with the sensor.
[0027] During measurement, the measuring point on the inner race of the bearing contacts the sensor. The friction force of the bearing acts on the sensor through the measuring point, passes through the secondary instrument, and then changes into a corresponding electrical signal output.
[0028] The output electrical signal is input into the computer data acquisition and processing system for recording.
[0029] Preferably, during the measurement, the measuring point is in contact with the sensor, and the bearing friction force acts on the sensor;
[0030] When the outer ring of the bearing rotates, the transition shaft and the outer ring of the bearing match;
[0031] When the motor turns, the outer ring of the bearing rotates.
[0032] Preferably, the precision bearing dynamic friction torque test includes a computer processing system, a secondary instrument, a shielding mechanism, a sensor, a test head A, an outer race, a bearing outer ring, a bearing inner ring, a bearing adapter shaft, a tested bearing, and a test head B.
[0033] Preferably, each test data during the bearing dynamic friction torque test is regularly stored in a database, and test data query, statistics, graphing and printing output functions are provided;
[0034] The database uses Access database. The test data in the database can be queried according to test number, test time, product number and other conditions. The original data obtained by the query can be edited and plotted, and can be exported in the form of EXCEL spreadsheets. Data with different recording intervals are recorded in different data tables.
[0035] Preferably, the test head A and the test head B are symmetrically arranged on both sides of the outer race of the bearing to be tested.
[0036] Preferably, the bearing dynamic friction torque test is connected to a computer, which uses Advantech's 12.1-inch SVGA ultra-thin LCD industrial tablet computer. The computer provides two RS232 serial ports, one of which can also be configured as RS422 or RS485 serial port mode, and the computer is equipped with two RJ45 network cable interfaces.
[0037] Preferably, an acquisition card and a secondary instrument are used in the bearing dynamic friction torque test process, one connection end of the acquisition card is connected to the secondary instrument, and the other connection end of the secondary instrument is cooperatively connected to the friction force sensor and the loading force sensor.
[0038] Compared with the prior art, the present invention has the following beneficial effects:
[0039] (1) Test head A and test head B are symmetrically arranged on both sides of the outer race of the bearing to be tested. By symmetrically installing and testing on both sides, the deviation value of the bearing can be measured more accurately;
[0040] (2) The bearing dynamic friction torque test method uses one sensor to meet the test range requirements of common bearings. The test data can be used directly without conversion, which is convenient and has high test accuracy. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Figure 1 Schematic diagram of the bearing dynamic friction torque testing system of the present invention.
[0042] In the figure: 1. Computer processing system; 2. Secondary instrument; 3. Shielding mechanism; 4. Sensor; 5. Test head A; 6. Outer race; 7. Bearing outer race; 8. Bearing inner race; 9. Bearing adapter shaft; 10. Bearing under test; 11. Test head B. DETAILED DESCRIPTION
[0043] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0044] See also Figure 1 The present invention provides a technical solution: a method for testing the dynamic friction torque of a precision bearing. During the test of the dynamic friction torque of a bearing:
[0045] The test bearing is installed on the bearing adapter shaft of the equipment. When the main shaft rotates, the inner ring of the bearing is driven to rotate. Due to the friction of the bearing, test heads A and B are symmetrically installed on the outer race of the bearing. During measurement, the measuring point contacts the sensor.
[0046] The dynamic friction torque test of the precision bearing includes a computer processing system 1, a secondary instrument 2, a shielding mechanism 3, a sensor 4, a test head A5, an outer race 6, a bearing outer race 7, a bearing inner race 8, a bearing adapter shaft 9, a tested bearing 10, and a test head B11. The computer processing system 1, the secondary instrument 2, the shielding mechanism 3, and the sensor 4 are connected in series. The test head A5 and the test head B11 are symmetrically arranged on both sides of the outer race 6 of the tested bearing 10. Through symmetrical installation and detection on both sides, the deviation value of the bearing can be measured more accurately.
[0047] During the bearing dynamic friction torque test, an acquisition card and a secondary instrument 2 are used. One connection end of the acquisition card is connected to the secondary instrument 2, and the other connection end of the secondary instrument 2 is connected to a friction force sensor and a loading force sensor.
[0048] The dynamic friction torque test of the bearing is connected to a computer. The computer uses Advantech's 12.1-inch SVGA ultra-thin LCD industrial tablet computer. The computer provides two RS232 serial ports, one of which can be configured as RS422 or RS485 serial port mode. At the same time, the computer is equipped with two RJ45 network cable interfaces, which is convenient for users to control and transfer data through network connection. In addition, the computer is equipped with three USB ports, two of which are USB2.0 and the other is USB3.0.
[0049] The computer configures the D port to RS485 mode, and connects to the RS485 switch module and analog module through the RS485 bus, thereby controlling the spindle speed, Z-axis speed, Z-axis limit and return to zero, Z-axis up and down movement, and pressurized cylinder pressure. The computer is connected to Advantech's data acquisition card at a high speed through the USB2.0 interface of the computer's F port, realizing data acquisition of the friction sensor and pressure sensor.
[0050] During measurement, the measuring point contacts the sensor, and the bearing friction force is applied to the sensor. When the outer ring of the bearing rotates, the transition shaft and the outer ring of the bearing match. When the motor rotates, the outer ring of the bearing rotates, and the measuring point on the inner race of the bearing contacts the sensor.
[0051] During the dynamic friction torque test of the bearing, each test data is stored in the database at a regular time, and the test data query, statistics, graphing and print output functions are provided. The database uses Access database. The test data in the database can be queried according to test number, test time, product number and other conditions. The original data obtained by the query can be edited and graphed, and can be exported in the form of EXCEL spreadsheets. Data with different recording intervals are recorded in different data tables.
[0052] The friction force of the bearing acts on the sensor through the measuring point, passes through the secondary instrument, and then changes into the corresponding electrical signal output. The output electrical signal is input into the computer data acquisition and processing system for recording to obtain the corresponding friction torque value and graph.
[0053] The bearing dynamic friction torque test method can meet the test range requirements of common bearings with one sensor, and the test data can be used directly without conversion, which is convenient and has high test accuracy.
[0054] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for testing dynamic friction torque of precision bearings, characterized by: During the bearing dynamic friction torque test: Install the test bearing on the bearing adapter shaft of the equipment. When the main shaft rotates, the inner ring of the bearing will rotate. Test heads A and B are symmetrically installed on the outer race of the bearing. During measurement, the measuring point is in contact with the sensor. During measurement, the measuring point on the inner race of the bearing contacts the sensor. The friction force of the bearing acts on the sensor through the measuring point, passes through the secondary instrument, and then changes into a corresponding electrical signal output. The output electrical signal is input into the computer data acquisition and processing system for recording.
2. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: During the measurement, the measuring point is in contact with the sensor, and the bearing friction force acts on the sensor; When the outer ring of the bearing rotates, the transition shaft and the outer ring of the bearing match; When the motor turns, the outer ring of the bearing rotates.
3. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: The precision bearing dynamic friction torque test comprises a computer processing system (1), a secondary instrument (2), a shielding mechanism (3), a sensor (4), a test head A (5), an outer race (6), a bearing outer race (7), a bearing inner race (8), a bearing adapter shaft (9), a tested bearing (10), and a test head B (11).
4. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: During the bearing dynamic friction torque test, each test data is regularly stored in the database, and the test data query, statistics, drawing and printing output functions are provided; The database uses Access database. The test data in the database can be queried according to test number, test time, product number and other conditions. The original data obtained by the query can be edited and plotted, and can be exported in the form of EXCEL spreadsheets. Data with different recording intervals are recorded in different data tables.
5. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: The test head A (5) and the test head B (11) are symmetrically arranged on both sides of the outer race (6) of the bearing (10) to be tested.
6. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: The bearing dynamic friction torque test is connected to a computer, which uses Advantech's 12.1-inch SVGA ultra-thin LCD industrial tablet computer. The computer provides two RS232 serial ports, one of which can also be configured as RS422 or RS485 serial port mode, and the computer is equipped with two RJ45 network cable interfaces.
7. A method for testing dynamic friction torque of precision bearings according to claim 1, characterized in that: During the bearing dynamic friction torque test, an acquisition card and a secondary instrument (2) are used; one connection end of the acquisition card is connected to the secondary instrument (2); and the other connection end of the secondary instrument (2) is cooperatively connected to a friction force sensor and a loading force sensor.