A method for testing heat generation of a cylindrical roller bearing

Abstract

The application provides a cylindrical roller bearing heat generation test method, which is tested by using a cylindrical roller bearing heat generation test experimental device. The cylindrical roller bearing heat generation test experimental device comprises a test main shaft, one end of the test main shaft is sequentially connected with a speed increasing gear box and a drag motor, and a main tester is arranged on the other end of the test main shaft. An external abutting loading electric cylinder assembly is arranged on the main tester, and the loading electric cylinder assembly performs axial loading and radial loading on the main tester. The main tester comprises a test bearing which is sleeved on the end of the main shaft, an external connecting shell is arranged on the test bearing, an oil injection seat is arranged at one end of the shell, and a nozzle is arranged on the oil injection seat to perform injection lubrication on the test bearing. The application can complete the test and test work of the cylindrical roller bearing, change the rotating speed and the load size, realize the injection lubrication test and test, change the oil inlet flow and temperature, can test different types of bearings and oils, and can ensure the accuracy of the test results.

Description

Technical Field

[0001] This invention belongs to the field of bearing heat generation experiments, specifically relating to a method for testing the heat generation of cylindrical roller bearings. Background Technology

[0002] In various aerospace power systems such as aero gas turbine engines and turbine-based combined engines, cylindrical roller bearings are typically used for the front support of the rotating main shaft. As the core support of the engine rotor system, the main shaft bearing is crucial for ensuring stable engine operation and performance. For the main shaft bearing, insufficient cooling leading to "shaft seizure," as well as oil ignition and coking caused by high temperatures, can cause fatal damage to the aero-engine and are unacceptable situations. Therefore, modern engine design must select more effective cooling solutions to ensure reliable operation of the main shaft bearing and improve system efficiency and engine reliability. When designing a cooling solution, thermal analysis of the bearing is required, which presupposes the calculation of the heat generated by the bearing. However, with the continuous improvement of aero-engine performance, the bearing DN value (the product of the bearing inner diameter (mm) and the bearing speed (rpm)) is constantly increasing. Coupled with the complex operating conditions of the engine, accurately predicting the heat generated by the cylindrical roller bearing is a problem that urgently needs to be solved. In order to study the magnitude and variation of heat generation in cylindrical roller bearings more deeply, it is necessary to develop a test device that can test bearing heat generation under various operating conditions. This is of great significance for the research of aero-engine mechanical systems.

[0003] Unlike pressure and temperature, "heat generation" is a data point that cannot be directly measured. Currently, the experimental measurement method for heat generation is based on calculations using experimental temperature data and the law of conservation of energy. Most testing apparatuses place the return oil temperature measurement point inside the return oil pipe, or even inside the return oil tank. However, between the lubricating oil cooling the bearing and reaching the aforementioned temperature measurement point, there is heat exchange between the lubricating oil and the gas inside the bearing test chamber, the walls of the bearing test chamber, and the walls of the return oil pipe. This means that the experimental data at the actual temperature measurement point cannot truly reflect the temperature of the lubricating oil at the bearing outlet, and the calculated heat generation will therefore have a significant error. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the purpose of this invention is to propose a method for testing the heat generation of cylindrical roller bearings.

[0005] The present invention is implemented using the following technical solution:

[0006] A method for testing the heat generation of cylindrical roller bearings is disclosed, which employs a cylindrical roller bearing heat generation testing experimental device. The experimental device includes a test spindle, one end of which is sequentially connected to a speed-increasing gearbox and a drive motor. A main tester is mounted on the other end of the test spindle, and a loading electric cylinder assembly is externally connected to the main tester. The loading electric cylinder assembly applies axial and radial loading to the main tester.

[0007] The main test apparatus includes a test bearing sleeved on the end of the main shaft, a housing is connected to the outside of the test bearing, an oil spray seat is connected to one end of the housing, and a nozzle is provided on the oil spray seat for spraying lubrication to the test bearing;

[0008] The testing method includes measuring the oil slinger temperature of the inner end face and the oil slinger temperature of the outer end face of multiple sets of test bearings 21. The measured oil slinger temperatures of the inner and outer end faces are fitted in polar coordinates to obtain spline curve one representing the circumferential distribution of the oil slinger temperature of the inner end face and spline curve two representing the circumferential distribution of the oil slinger temperature of the outer end face in polar coordinates. The average value curve of the first and second spline curves is then calculated. The first value curve in the average value curve... i The temperature value is , i ∈[1,n], n The number of interpolations is a positive integer greater than or equal to 1.

[0009] The heat generated Q of the test bearing 21 is calculated according to the law of conservation of energy using the following formula;

[0010]

[0011] In the formula, Specific heat capacity of lubricating oil, J / kg·K; The density of the lubricating oil is expressed in kg / m³. 3 ; For the inlet lubricating oil flow rate, m 3 / s; ℃; The bearing oil supply temperature is ℃.

[0012] Furthermore, an oil baffle is provided on the housing near the test bearing, and a temperature sensor is provided on the oil baffle.

[0013] Furthermore, the oil injection seat does not contact the main shaft, and the housing is provided with a first chamber and a second chamber, which are located on both sides of the test bearing, respectively.

[0014] Furthermore, an oil inlet pipe is provided on the fuel injector seat in communication with the nozzle, a first return oil pipe is provided at the bottom of the first chamber, and a second return oil pipe is provided at the bottom of the second chamber.

[0015] Furthermore, a test ball bearing and a test roller bearing are also fitted onto the main shaft, with the test roller bearing located between the test ball bearing and the test bearing.

[0016] Furthermore, the main test chamber includes an upper chamber, a lower chamber, and an axial loading ring. The upper chamber is connected to the test ball bearing and the test roller bearing respectively and is located above the main shaft. The lower chamber is connected to the test ball bearing and the test roller bearing respectively and is located below the main shaft.

[0017] Furthermore, the loading electric cylinder assembly includes a first buffer coaxially arranged with the main shaft, and the axial loading ring is connected to the upper housing and the lower housing and sleeved on the first buffer.

[0018] Furthermore, the loading electric cylinder assembly also includes a second buffer arranged perpendicular to the main shaft. The first buffer is coaxially connected to the first electric cylinder, and the second buffer is coaxially connected to the second electric cylinder. The first electric cylinder performs axial loading on the test bearing, and the second electric cylinder performs radial loading on the test bearing.

[0019] Furthermore, a bearing bushing is fitted between the test bearing and the main shaft.

[0020] Compared with the prior art, the present invention has the following technical effects:

[0021] The bearing temperature measurement point of this invention is set on the oil baffle plate of the bearing, which overcomes the measurement error problem caused by the traditional bearing heat generation outlet measurement point being arranged near the oil return pipe outlet. It can complete the test work of cylindrical roller bearings, change the rotation speed, change the load, realize the jet lubrication test, change the lubricating oil inlet flow rate and temperature, test different types of bearings and lubricating oil, and ensure the accuracy of the test results. Attached Figure Description

[0022] Figure 1 This is an experimental setup for testing bearing heat generation.

[0023] Figure 2 A partial schematic diagram of the main test chamber;

[0024] Figure 3 A schematic diagram of the measurement points on the outer end face of the bearing;

[0025] Figure 4 A schematic diagram of the measurement points on the inner end face of the bearing;

[0026] Figure 5 This is a test oil slingshot temperature spline curve.

[0027] Figure 6This is the average value curve after interpolation of the oil spill temperature spline curve under test conditions.

[0028] The labels in the diagram represent:

[0029] 1. Test spindle; 11. Test ball bearing; 12. Test roller bearing; 2. Main test apparatus; 21. Test bearing; 22. Housing; 22-1. Oil baffle; 22-2. First chamber; 22-3. Second chamber; 23. Oil injection seat; 23-1. Oil inlet pipe; 23-2. Nozzle; 24. Bearing bushing; 25. First oil return pipe; 26. Second oil return pipe; 3. First buffer; 31. Axial loading ring; 4. Main test chamber; 41. Upper chamber; 42. Lower chamber.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0031] The following provides specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0032] It should be noted that in the directional description of this invention, the terms "one end," "the other end," "above," "below," "left," and "right," etc., indicate the orientation or positional relationship only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "Inner" and "outer" refer to the core outside the outline of the corresponding component, and should not be construed as limitations on the invention. If the specific orientation changes, the directional indication will also change accordingly. In this invention, unless otherwise explicitly specified and limited, the terms "connected," "fixed," etc., should be interpreted broadly. For example, "fixed" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction relationship between two components, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0033] The actuating motor, speed-increasing gearbox, and loading electric cylinder assembly in this invention are all commonly used devices in the field.

[0034] In this invention, spline interpolation refers to a mathematical method for constructing a smooth curve passing through a series of points using variable splines. An interpolation spline is composed of polynomials, each determined by two adjacent data points. Thus, any two adjacent polynomials and their derivatives are continuous at the connection point. Spline interpolation determines a function between every two points; this function is a spline. Different functions result in different splines, hence the term "variable spline" in the definition. Finally, all splines are piecewise combined into a single function, which is the final interpolation function.

[0035] The experimental apparatus for testing the heat generation of cylindrical roller bearings according to the present invention can meet the requirements of experimental research on the heat generation of cylindrical roller bearings.

[0036] (1) Test the amount of heat generated by cylindrical roller bearings under different speed conditions;

[0037] (2) Test the amount of heat generated by cylindrical roller bearings under different load conditions;

[0038] (3) Test the amount of heat generated by the cylindrical roller bearing under jet lubrication conditions;

[0039] (4) Test the amount of heat generated by cylindrical roller bearings under different lubricating oil inlet temperatures;

[0040] (5) Test the amount of heat generated by cylindrical roller bearings under different lubricating oil flow rates.

[0041] Example 1:

[0042] Following the above technical solution, combined with Figure 1 and Figure 2 As shown, this embodiment discloses a test device for testing the heat generation of cylindrical roller bearings, including a test spindle 1. One end of the test spindle 1 is connected to a speed-increasing gearbox and a drive motor in sequence. A main tester 2 is set on the other end of the test spindle 1. The outside of the main tester 2 abuts against a loading electric cylinder assembly, which performs axial and radial loading on the main tester 2.

[0043] The main tester 2 includes a test bearing 21 sleeved on the end of the main shaft. A housing 22 is connected to the outside of the test bearing 21. An oil spray seat 23 is connected to one end of the housing 22. A nozzle 23-2 is provided on the oil spray seat 23 for spraying lubrication to the test bearing 21.

[0044] With this setup, the speed-increasing gearbox and drive motor provide high-precision speed conditions for the cylindrical roller bearing heat generation test. Adjusting the drive motor allows for speed adjustment of the test bearing 21. The overall oil spray seat 23 can be replaced according to different experimental requirements to spray lubricate the test bearing 21.

[0045] Furthermore, an oil baffle 22-1 is provided on the housing 22 near the test bearing 21, and a temperature sensor is provided on the oil baffle 22-1.

[0046] With this configuration, the lubricating oil used for cooling and lubrication inside the bearing is thrown off the bearing and onto the oil baffles 22-1 on both sides of the bearing. Surface-mount temperature sensors are installed on the oil baffles 22-1 to measure the temperature of the thrown oil. Setting the temperature measurement point of the cylindrical roller bearing on the oil baffles 22-1 overcomes the measurement error problem caused by the traditional bearing heat generation outlet measurement point being located near the oil return pipe outlet. Preferably, multiple oil baffles 22-1 can be used.

[0047] Furthermore, the oil injection seat 23 does not contact the main shaft, and the housing 22 is provided with a first chamber 22-2 and a second chamber 22-3, which are located on both sides of the test bearing 21, respectively.

[0048] Furthermore, an oil inlet pipe 23-1 is provided on the fuel injector seat 23 in connection with the nozzle 23-2, a first return oil pipe 25 is provided at the bottom of the first chamber 22-2, and a second return oil pipe 26 is provided at the bottom of the second chamber 22-3.

[0049] With this configuration, the first chamber 22-2 and the second chamber 22-3 adopt separate oil return methods. The oil return points are located at the lowest points of the first chamber 22-2 and the second chamber 22-3, respectively. The oil returns after entering the first oil return pipe 25 and the second oil return pipe 26 and then leaving the main test chamber 4. The oil return can be achieved by pumping oil to avoid oil accumulation in the chamber.

[0050] Furthermore, a test ball bearing 11 and a test roller bearing 12 are also fitted on the main shaft, with the test roller bearing 12 located between the test ball bearing 11 and the test bearing 21.

[0051] With this setup, the test bearing 21 needs to be loaded, and its radial and axial loads are borne by the test ball bearing 11 and the test roller bearing 12 to help the device operate normally.

[0052] As a preferred example of this embodiment, the main test chamber 4 includes an upper chamber 41, a lower chamber 42 and an axial loading ring 31. The upper chamber 41 is connected to the test ball bearing 11 and the test roller bearing 12 respectively and is located above the main shaft. The lower chamber 42 is connected to the test ball bearing 11 and the test roller bearing 12 respectively and is located below the main shaft.

[0053] Furthermore, the loading electric cylinder assembly includes a first buffer 3 coaxially arranged with the main shaft, and an axial loading ring 31 connected to the upper housing 41 and the lower housing 42 and sleeved on the first buffer 3. The first buffer 3 is used to protect the main tester 2.

[0054] With this configuration, both the upper housing 41 and the lower housing 42 are cast in shape to protect the main test chamber 4. The first buffer 3 is used to protect the main test chamber 2.

[0055] As a preferred example of this embodiment, the loading electric cylinder assembly further includes a second buffer arranged perpendicular to the main shaft. The first buffer 3 is coaxially connected to the first electric cylinder (not shown in the figure), and the second buffer is coaxially connected to the second electric cylinder (not shown in the figure). The first electric cylinder realizes axial loading on the test bearing 21, and the second electric cylinder realizes radial loading on the test bearing 21.

[0056] With this configuration, the radial and axial loading of the test bearing 21 can be achieved by setting the output torque of the motor shafts of the first and second electric cylinders. Adjustment blocks (not shown in the figure) are designed on the first and second electric cylinders for fine-tuning the position of the electric cylinders after the equipment is centered.

[0057] Furthermore, a bearing bushing 24 is fitted between the test bearing 21 and the spindle. The bearing bushing 24 can be adjusted and replaced according to the size of the test bearing 21 to meet the testing of bearings of different sizes. The bearing bushing 24 and the test spindle 1 are interference fit.

[0058] Example 2

[0059] This embodiment discloses a method for testing the heat generation of cylindrical roller bearings. The experimental apparatus for testing the heat generation of cylindrical roller bearings in Embodiment 1 is used. The heat generation of the cylindrical roller bearing is calculated based on the changes in the lubricating oil inlet and the oil slingshot temperature. Lubricating oil has two main functions: providing good lubrication conditions for bearing operation and cooling the bearing. The heat generated by the bearing is transferred to the lubricating oil through convection heat transfer, causing the lubricating oil temperature to rise. According to the law of conservation of energy, the increase in the internal energy of the lubricating oil is the heat generation of the cylindrical roller bearing.

[0060] The testing method includes measuring the oil slinger temperature of the inner end face and the oil slinger temperature of the outer end face of multiple sets of test bearings 21. The measured oil slinger temperatures of the inner and outer end faces are fitted in polar coordinates to obtain spline curve one representing the circumferential distribution of the oil slinger temperature of the inner end face and spline curve two representing the circumferential distribution of the oil slinger temperature of the outer end face in polar coordinates. The average value curve of the first and second spline curves is then calculated. The first value curve in the average value curve... i The temperature value is , i ∈[1,n], n This represents the number of interpolations.

[0061] The heat generated Q of the test bearing 21 is calculated according to the law of conservation of energy using the following formula;

[0062]

[0063] In the formula, Specific heat capacity of lubricating oil, J / kg·K; The density of the lubricating oil is expressed in kg / m³. 3 ; For the inlet lubricating oil flow rate, m 3 / s; ℃; The bearing oil supply temperature is ℃.

[0064] The polar coordinates of a spline curve are represented as: P(r,θ), where r represents the polar radius and θ represents the polar angle. The polar radius r represents the temperature value, and the polar angle θ also represents the circumferential coordinate. Each polar angle corresponds to a polar radius, that is, each circumferential coordinate corresponds to the temperature value at that location.

[0065] Specifically, "finding the average value curve of spline curve one and spline curve two" means, in a polar coordinate system, summing and averaging the n temperature values ​​from spline curve one and spline curve two to obtain the average value curve, where the polar radius r in the average value curve represents the outlet temperature. T out .

[0066] Specifically, before the test begins, the testing apparatus is first inspected. After confirming that the apparatus is functioning correctly, the test bearing is fixed on the bearing housing. The oil supply system and the drive motor are then turned on. The rotational speed and oil flow rate are adjusted according to the test requirements. The bearing is then loaded by adjusting the axial and radial loading electric cylinders. Once the apparatus is running stably, the inlet and sling oil temperatures and flow rates are measured using temperature sensors and flow meters, and the data are recorded. After the test, the loading electric cylinders are first turned off, then the drive motor is turned off to stop the shaft rotation, and finally the lubricating oil pump is turned off to stop the oil supply.

[0067] Using a set of experimental data as an example, this paper introduces the method for processing the temperature data results measured in the experiment.

[0068] For the cylindrical roller bearing with model number C842725S3KW1U, the external dimensions (d×D×B / C) are φ125 0-0.01×φ179 0-0.01×31 0-0.12 / 36 0-0.2, where d represents the inner diameter of the inner ring of the test bearing, D represents the outer diameter of the outer ring of the test bearing, B represents the width of the inner ring of the test bearing, and C represents the width of the outer ring of the test bearing, all in mm.

[0069] Under the operating conditions shown in Table 1, the oil slinger temperature of the inner end face and the oil slinger temperature of the outer end face of the test bearing were tested. Specifically, measuring points 1, 2, and 3 are any three measuring points on the outer end face of the bearing that are 120° apart, and measuring points 4, 5, and 6 are any three measuring points on the inner end face of the bearing that are 120° apart. Here, inner and outer sides refer to the left and right sides of the bearing in the top view. The test data measured by the temperature sensors on the oil baffles set on both sides (inner and outer) of the test bearing are shown in Table 2.

[0070] Table 1 Test Operating Conditions

[0071]

[0072] Table 2 Experimental Measurement Data

[0073]

[0074] The measured oil slinging temperatures of the inner and outer end faces were fitted in polar coordinates to obtain two spline curves showing the circumferential distribution of the oil slinging temperature of the inner end face and the outer end face in polar coordinates. Figure 5 Find the average curves of spline curve 1 and spline curve 2, such as... Figure 6 As shown.

[0075] In this process, n is 999, and the calculated heat generation of the bearing is 3.75kW.

[0076] The above embodiments further illustrate the purpose, technical solution, and advantages of the present invention in detail. It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0077] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0078] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0079] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content invented by this disclosure.

Claims

1. A method for testing heat generation in cylindrical roller bearings, characterized in that, The test was conducted using a cylindrical roller bearing heat generation test device, which includes a test spindle (1). One end of the test spindle (1) is connected to a speed-increasing gearbox and a drive motor in sequence. A main tester (2) is set on the other end of the test spindle (1). The main tester (2) is externally connected to a loading electric cylinder assembly, which applies axial and radial loading to the main tester (2). The main tester (2) includes a test bearing (21) sleeved on the end of the main shaft. A housing (22) is connected to the outside of the test bearing (21). An oil spray seat (23) is connected to one end of the housing (22). A nozzle (23-2) is provided on the oil spray seat (23) for spraying lubrication to the test bearing (21). An oil baffle (22-1) is provided on the housing (22) near the test bearing (21), and a temperature sensor is provided on the oil baffle (22-1); The testing method includes using the temperature sensor to measure the oil slinger temperature of the inner end face and the oil slinger temperature of the outer end face of multiple test bearings (21), performing polar coordinate fitting on the measured inner end face oil slinger temperature and the outer end face oil slinger temperature respectively, obtaining spline curve one of the circumferential distribution of the inner end face oil slinger temperature and spline curve two of the circumferential distribution of the outer end face oil slinger temperature in the polar coordinate system, and calculating the average value curve of the first and second spline curves. The first value curve in the average value curve is... i The temperature value is , i ∈[1,n], n This represents the number of interpolations. The heat generated Q of the test bearing (21) is calculated according to the law of conservation of energy using the following formula; In the formula, Specific heat capacity of lubricating oil, J / kg·K; The density of the lubricating oil is expressed in kg / m³. 3 ; For the inlet lubricating oil flow rate, m 3 / s; ℃; The bearing oil supply temperature is given in °C. The inner end face and the outer end face refer to the left and right sides of the bearing, respectively.

2. The method for testing heat generation in cylindrical roller bearings according to claim 1, characterized in that, The oil injection seat (23) does not contact the main shaft. The housing (22) is provided with a first chamber (22-2) and a second chamber (22-3). The first chamber (22-2) and the second chamber (22-3) are located on both sides of the test bearing (21).

3. The method for testing heat generation in cylindrical roller bearings according to claim 2, characterized in that, An oil inlet pipe (23-1) is provided on the oil injector seat (23) in connection with the nozzle (23-2), a first return oil pipe (25) is provided at the bottom of the first chamber (22-2), and a second return oil pipe (26) is provided at the bottom of the second chamber (22-3).

4. The method for testing heat generation in cylindrical roller bearings according to claim 1, characterized in that, The main shaft is also fitted with a test ball bearing (11) and a test roller bearing (12), with the test roller bearing (12) located between the test ball bearing (11) and the test bearing (21).

5. The method for testing heat generation in cylindrical roller bearings according to claim 4, characterized in that, It also includes a main test chamber (4), which includes an upper chamber (41), a lower chamber (42) and an axial loading ring (31). The upper chamber (41) is connected to the test ball bearing (11) and the test roller bearing (12) respectively and is located above the main shaft. The lower chamber (42) is connected to the test ball bearing (11) and the test roller bearing (12) respectively and is located below the main shaft.

6. The method for testing heat generation in cylindrical roller bearings according to claim 5, characterized in that, The loading electric cylinder assembly includes a first buffer (3) coaxially arranged with the main shaft, and the axial loading ring (31) is connected to the upper housing (41) and the lower housing (42) and sleeved on the first buffer (3).

7. The method for testing heat generation in cylindrical roller bearings according to claim 6, characterized in that, The loading electric cylinder assembly also includes a second buffer that is perpendicular to the main shaft. The first buffer (3) is coaxially connected to the first electric cylinder, and the second buffer is coaxially connected to the second electric cylinder. The first electric cylinder performs axial loading on the test bearing (21), and the second electric cylinder performs radial loading on the test bearing (21).

8. The method for testing heat generation in cylindrical roller bearings according to claim 1, characterized in that, A bearing bushing (24) is fitted between the test bearing (21) and the main shaft.

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