Aviation bearing temperature rise prediction method and system based on high-temperature test device

Abstract

The invention relates to an aviation bearing temperature rise prediction technology, and discloses an aviation bearing temperature rise prediction method and system based on a high temperature test device, and the method comprises the steps: obtaining a working clearance through a thermodynamic theory; constructing a contact load-deformation relation and a contact load-drag force relation between the rolling body and the ring raceway to calculate the viscous resistance; a heat-fluid-solid coupled bearing quasi-dynamic loading force balance equation is constructed; carrying out iterative solution on the bearing quasi-dynamic loading force balance equation and calculating the heat generation of the bearing according to a solution result; and constructing a bearing thermal boundary condition according to a bearing high-temperature simulation test result to carry out heat generation distribution, establishing a bearing thermal balance equation according to a distribution result and the calculated contact position thermal resistance, and carrying out iterative solution to obtain a temperature rise result. According to the method, the temperature distribution of each part of the bearing can be quickly obtained, and a theoretical method with more comprehensive consideration factors is provided for the optimization design of the internal structure of the aviation bearing and the matching design of the bearing, the shaft and the bearing seat.

Description

Technical Field

[0001] The invention belongs to the field of mechanical engineering, and relates to a temperature rise prediction technology for an aviation bearing, and in particular to a temperature rise prediction method and system for an aviation bearing based on a high temperature test device. Background Art

[0002] As one of the key components of aircraft engines, aviation bearings are mainly used to support high and low rotor systems and transfer loads, and play an extremely critical role in the reliable operation of the engine. With the continuous breakthrough and improvement of the ultimate performance of aircraft engines, higher performance requirements are put forward for aircraft bearings. At present, the early failure of aircraft engine bearings such as wear, burns and seizure caused by high temperature has become one of the key factors restricting the development of engines to long life, strong ultimate performance and high reliability, which in turn affects the life, load-bearing capacity, reliability and dynamic performance of aircraft engines.

[0003] In recent years, some scholars at home and abroad have carried out a lot of theoretical analysis on the heat generation and temperature rise of aviation bearings. The heat generation and temperature rise of bearings are mainly calculated by the overall method or the local method. This method is based on the traditional bearing pseudo-static model or pseudo-dynamic model. This method does not consider the influence of the coupling between the internal structure, temperature and lubrication of the bearing, and does not consider the influence of the oil supply under the ring, heat distribution and the bearing thermal boundary on the bearing load distribution and motion characteristics, and thus it is difficult to accurately reflect the internal movement and heat generation mechanism of the bearing under working conditions.

[0004] In addition, current temperature test experiments on aviation bearings are usually conducted based on bearing testers, which fail to truly simulate the high temperature environment of the bearing cavity, resulting in low accuracy in bearing performance evaluation, and making it even more difficult to reflect the temperature rise of aviation bearings in real time under real high temperature environments.

[0005] In general, the existing aviation bearing temperature assessment method generally first calculates the bearing heat generation through empirical formulas, then analyzes the bearing temperature field distribution through simulation, and finally verifies it through bearing tester tests and engine whole machine tests. This method has the following disadvantages: (1) The bearing heat generation and temperature simulation fails to consider the thermal-fluid-solid coupling effect, resulting in low simulation accuracy; (2) The bearing tester test is difficult to simulate the high-temperature working environment, resulting in large test errors; (3) The engine whole machine test involves many factors and a complex structure, making it difficult to accurately assess the internal temperature distribution of the bearing, resulting in a large gap between the existing aviation bearing temperature simulation results and the test results, making it difficult to verify each other and inconvenient for engineering application.

[0006] Therefore, there is an urgent need for a method that can quickly and accurately simulate and predict the operating temperature of aviation bearings, so as to explore the working performance of aviation bearings under the conditions of thermal-fluid-solid multi-physics field coupling, optimize the design of internal structural parameters of aviation bearings and reasonably select external boundary conditions. At the same time, it can also provide more accurate boundary input for the design of bearing cavity structure and lubricating oil system, so as to improve the working reliability of rotor-support system. Summary of the invention

[0007] In order to quickly and accurately simulate and predict the operating temperature of an aviation bearing and to explore the working performance of an aviation bearing under the condition of thermal-fluid-solid multi-physics field coupling, the present invention discloses a method for predicting the temperature rise of an aviation bearing based on a high temperature test device, the method comprising the following steps: S1. Heating the test bearing to collect the temperature of the outer ring of the bearing, taking the temperature of the outer ring of the bearing as the initial working temperature of each part of the bearing, and obtaining the working clearance of the test bearing by using the temperature of the outer ring of the bearing, the structural parameters and the material parameters of the test bearing through the theory of thermodynamics; S2, constructing a contact load-deformation relationship between the rolling element and the ring raceway according to the bearing coordinate system, the working clearance and the oil film thickness, establishing a contact load-drag force relationship between the rolling element and the ring raceway under a given bearing inner ring speed condition, and calculating the viscous resistance borne by the rolling element according to the rolling element revolution angular velocity and the density of the oil-gas mixture; S3, constructing a thermal-fluid-solid coupled bearing pseudo-dynamic load balance equation according to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and torque between the rolling element and the cage pocket, the force and torque between the cage and the guide ring, and the inertia force and torque of the rolling element; S4, iteratively solving the pseudo-dynamic load balance equation of the bearing, and calculating the heat generated by the bearing according to the iterative solution result; S5. Construct the thermal boundary conditions of the bearing according to the results of the high-temperature simulation test of the bearing, distribute the heat generated by the bearing through the heat generation mechanism, calculate the thermal resistance of the contact position of the test bearing under the condition of lubricating oil lubrication, establish the bearing thermal balance equation through the bearing heat distribution results and the contact position thermal resistance, and iteratively solve the bearing thermal balance equation to obtain the temperature rise of each part of the bearing.

[0008] Furthermore, in the above step S1, the test bearing is heated to collect the temperature of the outer ring of the bearing, the temperature of the outer ring of the bearing is used as the initial working temperature of each part of the bearing, and the working clearance of the test bearing is obtained by using the outer ring temperature of the bearing, the structural parameters and material parameters of the test bearing through the theory of thermodynamics, including: S11, heating the test bearing to collect the temperature of the outer ring of the bearing, and using the temperature of the outer ring of the bearing as the initial working temperature of the rotating shaft, inner ring, rolling element, outer ring and bearing seat of the test bearing; S12, according to thermodynamic theory, using linear expansion coefficient, part diameter, ambient temperature and initial working temperature, respectively calculate the thermal expansion of the inner ring, the rolling element and the outer ring, and calculate the temperature condition clearance reduction according to the thermal expansion; S13, calculating the working clearance of the test bearing according to the initial bearing clearance, the clearance reduction under the speed condition, the clearance reduction under the matching condition and the clearance reduction under the temperature condition.

[0009] Furthermore, in the above step S2, a contact load-deformation relationship between the rolling element and the ring raceway is established according to the bearing coordinate system, the working clearance, the load and the oil film thickness, including: S21, establishing the bearing coordinate system, wherein the bearing coordinate system includes an inertial coordinate system with the center of the outer ring of the test bearing as the origin, an inner ring coordinate system with the center of the inner ring as the origin, and an azimuth coordinate system with the center of each rolling element as the origin; S22, dividing each of the rolling elements into a plurality of slices along the length direction of the rolling element by a slicing method, and establishing a relationship between the oil film thickness and the deformation between the slices and the raceway of the ring according to the working clearance and the oil film thickness; S23, using the angular velocity of the ring, the distance between the slice and the ring, the angular velocity of the rolling body revolution and the angular velocity of the rolling body rotation, according to the inertial coordinate system, the inner ring coordinate system and the azimuth coordinate system, calculate the slice average velocity and the slice sliding velocity of the slice and the ring raceway, and establish the relationship between the oil film thickness and the contact load between the slice and the ring raceway according to the line contact elastohydrodynamic lubrication theory based on the slice average velocity; S24. Constructing a contact load-deformation relationship between the rolling element and the raceway of the ferrule based on the relationship between the oil film thickness and the deformation and the relationship between the oil film thickness and the contact load according to the Hertz contact theory.

[0010] Furthermore, in the above step S21, the expression of the relationship between the oil film thickness and the deformation is: ,in, For the j Rolling element i On a slice The distance between point φ and point P on the ferrule surface, For the j The deformation between the i-th slice of the rolling element and the ring, is the deformation caused by the rolling element convexity on the i-th slice, is the deflection angle of the bearing inner ring axis relative to the bearing outer ring axis, is the bearing angular position, is the oil film thickness between the ith slice of the jth rolling element and the ring, i is the slice number representing the ith slice, w is the slice thickness, P d It is the working clearance of the bearing.

[0011] Furthermore, in the above step S22, the expression of the relationship between the oil film thickness and the contact load is: ,in, For the j Rolling element i The average speed of the slices and the ring, is the equivalent elastic modulus of the rolling element and the ring ， is the equivalent radius of curvature of the rolling element and the ring, is the oil viscosity, is the viscosity-pressure coefficient, Q ji For the j Rolling element i The contact load between the slice and the ring, L r is the rolling element length, is the oil film correction factor considering thermal effects.

[0012] Furthermore, in the above step S2, the expression of the contact load-drag force relationship is: ,in, is the drag force between the ith slice and the ring in the jth rolling element, Q ji is the contact load of the i-th slice in the j-th rolling element, It is the friction coefficient between the rolling element and the ring raceway. This coefficient is related to the lubrication state and lubricating oil characteristics and can be measured through experiments.

[0013] Furthermore, in the above step S2, the formula for calculating the viscous resistance of the rolling element according to the rolling element's revolution angular velocity and the density of the oil-gas mixture is: , where F dj is the viscous resistance, ρ ef is the density of oil-gas mixture, D m is the bearing pitch diameter, C D is the damping coefficient, D w is the rolling element diameter, is the rolling body revolution angular velocity of the jth rolling body.

[0014] Furthermore, in the above step S3, according to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and moment between the rolling element and the cage pocket, the force and moment between the cage and the guide ring, and the inertia force and moment of the rolling element, a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation is constructed, including: S31, obtaining the force and torque between the rolling element and the cage pocket according to the long sliding bearing model, obtaining the force and torque between the cage and the guide ring according to the short sliding bearing model, and obtaining the rolling element inertia force and torque when the test bearing rotates according to theoretical mechanics; S32, establishing a force balance equation and a moment balance equation of the rolling body in thermal-fluid-solid coupling according to the force and moment between the rolling body and the cage pocket, the inertia force and moment of the rolling body, the contact load-deformation relationship and the viscous resistance; S33, taking the cage rotation speed as a constant value as a constraint condition during steady-state operation, and establishing a force balance equation and a moment balance equation of the cage under thermal-fluid-solid coupling according to the force and moment between the cage and the guide ring; S34. Under given external load conditions, according to the contact load-deformation relationship and the contact load-drag force relationship, the force balance equation and the torque balance equation of the inner ring of the thermal-fluid-solid coupling are established to complete the construction of the pseudo-dynamic load force balance equation of the bearing.

[0015] Furthermore, in the above step S5, the bearing thermal boundary conditions are constructed according to the bearing high temperature simulation test results, the bearing heat is distributed through the heat generation mechanism, the contact position thermal resistance of the test bearing is calculated under the lubricating oil lubrication condition, and the bearing thermal balance equation is established through the bearing heat distribution result and the contact position thermal resistance, including: S51, performing a high temperature simulation test on the test bearing to obtain the bearing high temperature simulation test results including the oil supply temperature, the bearing outer ring temperature and the bearing cavity temperature; S52, using the bearing high temperature simulation test result as a thermal boundary condition, and distributing heat generation according to the bearing heat generation, the bearing heat generation position, and the heat transfer ratio; S53. Under lubricating oil conditions, the thermal resistance of the contact position through which the lubricating oil flows is obtained by a thermal network method, and a bearing thermal balance equation is established by the heat distribution result and the thermal resistance of the contact position.

[0016] Furthermore, in the above step S5, the temperature rise of each part of the test bearing is obtained by iteratively solving the bearing thermal balance equation, including: The bearing thermal balance equation is iteratively solved by Gaussian elimination method and super relaxation iteration method until the result of this iteration is The result of the previous iteration The convergence accuracy of is less than a threshold value, and the temperature rise of each part of the test bearing is output.

[0017] An embodiment of the present invention also provides an aviation bearing temperature rise prediction system based on a high temperature test device, the system comprising a bearing high temperature simulation test device, a working clearance calculation module, a first building module, a viscous resistance calculation module, a second building module, a bearing heat generation acquisition module and a temperature rise calculation module.

[0018] Among them, the bearing high temperature simulation test device is used to perform a high temperature simulation test on the test bearing; the working clearance calculation module is used to obtain the working clearance of the test bearing through thermodynamic theory based on the bearing outer ring temperature; the first construction module is used to construct the contact load-deformation relationship and the contact load-drag force relationship; the viscous resistance calculation module is used to calculate the viscous resistance borne by the rolling body according to the rolling body's orbital angular velocity and the oil-gas mixture density; the second construction module is used to construct a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation; the bearing heat generation acquisition module is used to iteratively solve the bearing pseudo-dynamic load force balance equation, and calculate the bearing heat generation according to the iterative solution result; the temperature rise calculation module is used to construct the bearing thermal boundary conditions according to the bearing high temperature simulation test results, distribute the bearing heat generation through the heat generation mechanism, calculate the contact position thermal resistance of the test bearing under lubricating oil lubrication conditions, establish the bearing thermal balance equation through the bearing heat generation distribution result and the contact position thermal resistance, and iteratively solve the bearing thermal balance equation to obtain the temperature rise of each part of the bearing.

[0019] The method of the present invention simulates the high-temperature working state of aviation bearings, considers the influence of thermal conditions on bearing clearance, load distribution, speed distribution and lubrication characteristics during bearing operation, and proposes a bearing temperature rise prediction method based on the thermal-fluid-solid coupling effect according to the heat distribution law and heat exchange law inside the bearing. Based on this method, rapid iterative optimization of aviation bearing structure can be achieved, and a more accurate theoretical basis can be provided for the selection of the matching between bearings and shafts and bearing seats, so as to realize the temperature rise test assessment of aviation bearings under high temperature environment. This method has the following advantages: 1) The test simulation device can simulate the high-temperature working environment of aviation bearings. It uses electric heating to directly heat the peripheral temperature of the bearing. It has a fast heating speed and high temperature control accuracy, which is convenient for test implementation and provides an accurate thermal boundary for the temperature field analysis of aviation bearings under high temperature conditions. 2) This method takes into account the influence of thermal-mechanical conditions on the bearing load characteristics and the influence of the lubrication state of each contact pair on the bearing motion characteristics. Combined with the heat distribution law and heat exchange law inside the aviation bearing, it obtains more accurate bearing heat generation and temperature rise under the condition of thermal-fluid-solid coupling. It can quickly and accurately obtain the bearing temperature distribution during the bearing structure optimization design, providing a more accurate and reasonable basis for the selection of bearing matching parameters and external oil supply parameters. 2) This method is easy to implement in a process-based manner and can be compiled into a modular calculation program. Combined with the results of high-temperature simulation tests on bearings, it can realize real-time temperature rise prediction of aviation bearings in high-temperature environments, provide support for temperature rise test assessment of bearings in high-temperature environments other than engine whole-machine tests, and reduce test costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Figure 1 It is a flow chart of a method for predicting temperature rise of an aviation bearing based on a high temperature test device disclosed in an embodiment of the present invention; Figure 2 It is a principle block diagram of a method for predicting temperature rise of an aviation bearing based on a high temperature test device disclosed in an embodiment of the present invention; Figure 3 A schematic diagram of a bearing coordinate system disclosed in an embodiment of the present invention; Figure 4 A schematic diagram of the displacement of a rolling element disclosed in an embodiment of the present invention; Figure 5 A schematic diagram of a thermal network model of an aviation test bearing disclosed in an embodiment of the present invention; Figure 6 The heat transfer coefficient matrix result of the aviation cylindrical bearing disclosed in the embodiment of the present invention, that is, a schematic diagram of the temperature rise of various parts on the bearing; Figure 7 This is a schematic diagram of an aviation bearing temperature rise prediction system based on a high temperature test device disclosed in an embodiment of the present invention; Figure 8 A schematic diagram of a bearing high temperature simulation test device disclosed in an embodiment of the present invention; Among them, 701, bearing high temperature simulation test device; 702, working clearance calculation module; 703, first construction module; 704, viscous resistance calculation module; 705, second construction module; 706, bearing heat acquisition module; 707, temperature rise calculation module 607; 10, bearing support; 20, first lead connector; 30, second lead connector; 40, graphite seal; 50, rotor assembly; 60, oil supply nozzle; 70, test bearing; 80, oil retaining nut; 90, electric heater; 100, thermal insulation cover; 110, control system. DETAILED DESCRIPTION

[0022] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings. The following describes the embodiments of the present application by specific specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the features of the following embodiments and embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0023] The embodiment of the present invention discloses a method for predicting the temperature rise of an aviation bearing based on a high temperature test device, see Figure 1 and Figure 2 As shown, the method comprises the following steps: S1. Heating the test bearing to collect the temperature of the outer ring of the bearing, taking the temperature of the outer ring of the bearing as the initial working temperature of each part of the bearing, and obtaining the working clearance of the test bearing by using the temperature of the outer ring of the bearing, the structural parameters and the material parameters of the test bearing through the theory of thermodynamics; S2, constructing a contact load-deformation relationship between the rolling element and the ring raceway according to the bearing coordinate system, the working clearance and the oil film thickness, establishing a contact load-drag force relationship between the rolling element and the ring raceway under a given bearing inner ring speed condition, and calculating the viscous resistance borne by the rolling element according to the rolling element revolution angular velocity and the density of the oil-gas mixture; S3, constructing a thermal-fluid-solid coupled bearing pseudo-dynamic load balance equation according to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and torque between the rolling element and the cage pocket, the force and torque between the cage and the guide ring, and the inertia force and torque of the rolling element; S4, iteratively solving the pseudo-dynamic load balance equation of the bearing, and calculating the heat generated by the bearing according to the iterative solution result; S5. Construct the thermal boundary conditions of the bearing according to the results of the high-temperature simulation test of the bearing, distribute the heat generated by the bearing through the heat generation mechanism, calculate the thermal resistance of the contact position of the test bearing under the condition of lubricating oil lubrication, establish the bearing thermal balance equation through the bearing heat distribution results and the contact position thermal resistance, and iteratively solve the bearing thermal balance equation to obtain the temperature rise of each part of the bearing.

[0024] In an achievable embodiment of the above step S1, the test bearing is heated to collect the temperature of the outer ring of the bearing, the temperature of the outer ring of the bearing is used as the initial working temperature of each part of the bearing, and the working clearance of the test bearing is obtained by using the outer ring temperature of the bearing, the structural parameters and material parameters of the test bearing through the theory of thermodynamics, including: S11, heat the test bearing to collect the temperature of the outer ring of the bearing, and use the temperature of the outer ring of the bearing as the initial working temperature of the rotating shaft, inner ring, rolling element, outer ring and bearing seat in the test bearing. The initial working temperature of each component in the test bearing It can be expressed as ; Among them, T S is the shaft temperature, T2 is the inner ring temperature, T r is the rolling element temperature, T1 is the outer ring temperature, T h is the bearing seat temperature.

[0025] S12. According to thermodynamic theory, the thermal expansion coefficient, part diameter, ambient temperature and initial working temperature are used to calculate the thermal expansion of the inner ring, the rolling element and the outer ring respectively, and the clearance reduction under temperature conditions is calculated based on the thermal expansion; wherein the thermal expansion calculation formula of each part is: ,in, , and are the thermal expansion of the inner ring, rolling element and outer ring under the initial operating temperature T, , , are the linear expansion coefficients of the inner ring raceway, rolling element, and outer ring raceway, D2, D w , D1 are the diameters of the inner ring, rolling element, and outer ring respectively. T a is the ambient temperature, that is, the atmospheric temperature after the various parts of the test bearing are assembled. The reduction in clearance under temperature conditions can be calculated, that is, the reduction in working clearance after the test bearing has been thermally expanded and deformed under heating conditions.

[0026] S13, calculating the working clearance of the test bearing according to the initial bearing clearance, the clearance reduction under the speed condition, the clearance reduction under the matching condition and the clearance reduction under the temperature condition. P d The formula can be Calculated, where P d0 is the initial bearing clearance, is the clearance reduction caused by the speed (i.e. the clearance reduction under the speed condition), The clearance reduction caused by fit (i.e., the clearance reduction under fit conditions), the clearance reduction under speed conditions, and the clearance reduction under fit conditions can all be calculated based on traditional formulas.

[0027] Furthermore, in the above step S2, a contact load-deformation relationship between the rolling element and the ring raceway is established according to the bearing coordinate system, the working clearance, the load and the oil film thickness, including: S21, establish the bearing coordinate system, the bearing coordinate system includes an inertial coordinate system with the center of the outer ring of the test bearing as the origin, an inner ring coordinate system with the center of the inner ring as the origin, and an azimuth coordinate system with the center of each rolling element as the origin. Figure 3 As shown, the center of the outer ring is taken as the origin Establishing an inertial coordinate system , with the center of the inner ring as the origin Establish the inner circle coordinate system , with the center of the rolling element as the origin Establish an azimuth coordinate system for the origin .

[0028] S22, dividing each of the rolling elements into a plurality of slices along the length direction of the rolling element by a slicing method, and establishing a relationship between the oil film thickness and the deformation between the slices and the raceway of the ring according to the working clearance and the oil film thickness.

[0029] For more details, see Figure 4 As shown, j The rolling element is divided into N slices, then j Rolling element i On a slice The distance between point P and the surface of the ring is At the same time, considering the rolling element surface modification, rolling element deflection and oil film thickness, the j The first rolling element i The relationship between the deformation of a slice and a ring and the oil film thickness can be expressed as: ,in, For thej Rolling element i On a slice The distance between point φ and point P on the ferrule surface, For the j The deformation between the i-th slice of the rolling element and the ring, is the deformation caused by the rolling element convexity on the i-th slice, is the deflection angle of the bearing inner ring axis relative to the bearing outer ring axis, is the bearing angular position, is the oil film thickness between the ith slice of the jth rolling element and the ring, i is the slice number representing the ith slice, w is the slice thickness, P d It is the working clearance of the bearing.

[0030] More specifically, the expression can be divided into j The first rolling element i The relationship between the deformation of the outer ring and the inner ring and the oil film thickness of each slice includes the following two formulas: ; ,in, is the deformation between the i-th slice of the j-th rolling element and the outer ring, is the deformation between the i-th slice of the j-th rolling element and the inner ring, For the j Rolling element i On a slice The distance between point P1 on the outer ring surface is, For the j Rolling element i On a slice Point on the inner ring surface P The distance between 2 points, is the oil film thickness between the i-th slice of the j-th rolling element and the outer ring, is the oil film thickness between the i-th slice of the j-th rolling element and the inner ring.

[0031] S23, using the angular velocity of the ring, the distance between the slice and the ring, the angular velocity of the rolling body revolution and the angular velocity of the rolling body rotation, calculate the slice average velocity and the slice sliding velocity of the slice and the ring raceway according to the inertial coordinate system, the inner ring coordinate system and the azimuth coordinate system, and establish the relationship between the oil film thickness and the contact load between the slice and the ring raceway through the line contact elastohydrodynamic lubrication theory based on the slice average velocity.

[0032] In the specific implementation, the effect of the lubricating oil film between the rolling element and the outer ring and the inner ring is considered. According to the line contact elastohydrodynamic lubrication theory,j The first rolling element i The oil film thickness between the slice and the ring They are obtained by the following Hamrock-Dowson formula: ,in, For the j Rolling element i The average speed of the slices and the ring, is the equivalent elastic modulus of the rolling element and the ring, is the equivalent radius of curvature of the rolling element and the ring, is the oil viscosity, is the viscosity-pressure coefficient, Q ji For the j Rolling element i The contact load between the slice and the ring, L r is the rolling element length, is the oil film correction factor considering thermal effects.

[0033] The above Hamrock-Dowson formula can be divided into expressions for the rolling element, the outer ring and the inner ring, which include the following two formulas: ,in, is the oil film thickness between the i-th slice of the j-th rolling element and the outer ring, is the oil film thickness between the i-th slice of the j-th rolling element and the inner ring, For the j Rolling element i The average speed of the slices and the outer ring, For the j Rolling element i The average speed of the slices and the inner ring slices, is the equivalent elastic modulus of the rolling element and the outer ring, is the equivalent elastic modulus of the rolling element and the inner ring ， is the equivalent radius of curvature of the rolling element and the outer ring, is the equivalent radius of curvature of the rolling element and the inner ring, is the oil viscosity, is the viscosity-pressure coefficient, Q 1ji For the j Rolling element i The contact load between the slice and the outer ring, Q 2ji For the j Rolling element i The contact load between the slice and the inner ring,L r is the rolling element length, is the oil film correction factor considering thermal effects.

[0034] At the same time, since the influence of temperature on oil film thickness at high speed cannot be ignored, the formula Calculate the oil film correction factor considering thermal effects ,in, P h is the maximum Hertzian pressure, L is the heat load factor, is the equivalent elastic modulus of the rolling element and the ring, s is the slide-to-roll ratio.

[0035] Among them, the average slice speed and the slice sliding speed can be obtained by analyzing the bearing motion. Specifically, j Rolling element i The average speed of each slice and the surface of the outer ring and inner ring can be calculated by the following formulas: ; , where For the j The angular velocity of the rolling element, For the j The angular velocity of the rolling body, is the inner circle angular velocity, is the outer ring angular velocity, is the transformation matrix from the azimuth coordinate system to the inertial coordinate system, is the transformation matrix from the inner circle coordinate system to the inertial coordinate system, is the rolling element in the azimuth coordinate system P 1 to O rj The distance of the point, is the rolling element in the azimuth coordinate system P 2 to O rj The distance of the point, is the outer ring in the inertial coordinate system arrive O 1 point distance, is the inner circle on the inner circle coordinate system arrive O 2 points distance.

[0036] Similarly, j Rolling element i The sliding speeds of each slice and the outer ring and inner ring surface are expressed as: ; ,in, For the j Rolling element i The sliding speed between the slice and the outer ring surface, For the j Rolling element i The sliding speed between the slice and the inner ring surface.

[0037] Among them, the expression of the contact load-drag force relationship is: , is the drag force between the ith slice and the ring in the jth rolling element, Q ji is the contact load of the i-th slice in the j-th rolling element, It is the friction coefficient between the rolling element and the ring raceway. This coefficient is related to the lubrication state and lubricating oil characteristics and can be measured through experiments.

[0038] The formula for calculating the viscous resistance of the rolling element based on the rolling element's orbital angular velocity and the density of the oil-gas mixture is: , where F dj is the viscous resistance, ρ ef is the density of oil-gas mixture, D m is the bearing pitch diameter, C D is the damping coefficient, D w is the rolling element diameter, is the rolling body revolution angular velocity of the jth rolling body.

[0039] S24. Constructing a contact load-deformation relationship between the rolling element and the raceway of the ferrule based on the relationship between the oil film thickness and the deformation and the relationship between the oil film thickness and the contact load according to the Hertz contact theory.

[0040] Through the construction of several relationships in the above steps S22 to S23, according to the Hertz contact theory, the contact loads of the j-th rolling element in line contact with the inner ring and the outer ring can be calculated as follows: and The relationship between the deformation and the amount of deformation can be expressed by the following formula: , , where K2 is the load-deformation coefficient between the rolling element and the inner ring, and K1 is the load-deformation coefficient between the rolling element and the outer ring. is the contact load between the jth rolling element and the inner ring, is the contact load between the jth rolling element and the outer ring, is the deformation between the i-th slice of the j-th rolling element and the outer ring, is the deformation between the i-th slice of the j-th rolling element and the inner ring, which depends on the rolling element and the ring material itself and is a given value.

[0041] Through the above steps S22 to S24, after the bearing coordinate system is established, when the test bearing is subjected to a certain load, the slicing method is used to mesh the contact micro-area between the rolling element and the ring along the length direction, and the displacement-deformation coordination relationship of each slice of the rolling element is calculated through the relative position relationship between the rolling element and the inner ring and the outer ring. According to the Hertz contact theory, the contact load of each slice of the rolling element and the contact surface of the ring is obtained, and then the load-deformation relationship between the rolling element and the ring raceway is established.

[0042] Furthermore, in the above step S3, according to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and moment between the rolling element and the cage pocket, the force and moment between the cage and the guide ring, and the inertia force and moment of the rolling element, a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation is constructed, including: S31. Obtain the force and torque between the rolling element and the cage pocket according to the long sliding bearing model, obtain the force and torque between the cage and the guide ring according to the short sliding bearing model, and obtain the rolling element inertia force and torque when the test bearing rotates according to theoretical mechanics.

[0043] In specific implementation, the interaction force between the rolling element and the cage pocket is mainly generated by the fluid dynamic pressure effect of the lubricant, which mainly includes normal force and friction force. Since the pocket clearance is much smaller than the length of the rolling element, the interaction force between the cage pocket and the rolling element can be approximated as a "long sliding bearing" model, through which the interaction force and torque between the rolling element and the cage pocket can be obtained. Similarly, the interaction force between the cage and the guide ring (where the guide ring is the outer ring or inner ring that is closer to the cage) is mainly generated by the fluid dynamic pressure effect of the lubricant. According to the geometric characteristics of the cage and the guide ring, the ring guide surface and the cage centering surface can be regarded as a "short sliding bearing" model, through which the interaction force and torque between the cage and the guide ring can be obtained.

[0044] S32, according to the force and moment between the rolling element and the cage pocket, the inertia force and moment of the rolling element, the contact load-deformation relationship and the viscous resistance, establish the force balance equation and moment balance equation of the rolling element of thermal-fluid-solid coupling. Taking the jth rolling element as an example, the force balance equation and moment balance equation of the rolling element can be expressed as: , where F zj is the inertial force along the z direction, F yj is the inertial force along the y direction, Gxj is the moment of inertia about the x-axis, F cj is the normal force between the rolling element and the cage pocket, F dj is the viscous resistance, f rcj is the friction between the rolling element and the cage pocket, L r is the rolling element length, is the drag force between the i-th slice and the inner ring of the j-th rolling element, is the drag force between the i-th slice in the j-th rolling element and the outer ring.

[0045] S33. In steady-state operation, the cage rotation speed is set as a constant value as a constraint condition, and according to the force and torque between the cage and the guide ring, the force balance equation and torque balance equation of the cage of thermal-fluid-solid coupling are established. Specifically, it can be assumed that the cage rotation speed is a constant value in steady-state operation, and the force balance equation and torque balance equation of the cage can be expressed as: , where Z is the number of rolling elements, F cz is the force of the cage along the z direction, F cy is the force of the cage along the y direction, M cx is the moment of the cage around the x-axis, is the bearing angular position.

[0046] S34. Under given external load conditions, according to the contact load-deformation relationship and the contact load-drag force relationship, establish the force balance equation and torque balance equation of the inner ring of the thermal-fluid-solid coupling, and complete the construction of the pseudo-dynamic load force balance equation of the bearing. Specifically, considering the effect of the rolling element and the inner ring of the bearing, for the inner ring guided bearing, assume that the external load is , the force and moment balance equations of the inner ring are established as: , where Z is the number of rolling elements, e j For the j The eccentricity of the rolling element relative to the inner ring.

[0047] Furthermore, in step S4, the pseudo-dynamic load balance equation of the bearing is iteratively solved, and the heat generation of the bearing is calculated according to the iterative solution result, including: S41. The pseudo-dynamic load force balance equation of the bearing can be solved iteratively by the improved Newton-Raphson method, wherein the displacement value, oil film thickness and average velocity of the slice can be given an initial value by pseudo-statics during the initial calculation. When solving, the initial oil film thickness of the rolling element and the ring is first given, and the pseudo-dynamic load force balance equation (i.e., the force balance equation) is solved, and then the pseudo-dynamic velocity force balance equation (i.e., the torque balance equation) is solved iteratively. The coupled iterative variables are the oil film thickness of the rolling element and the ring. After solving, the various values ​​in the equation can be obtained.

[0048] S42. Calculate the heat generated by the bearing through iterative solution. The heat generated by the bearing is mainly composed of the following parts: a) The friction heat generated between the rolling element and the inner ring and outer ring is and ,in, is the drag force between the i-th slice and the inner ring of the j-th rolling element, For the j Rolling element i The sliding speed of each slice and the inner ring surface, For the j Rolling element i The sliding speed between the slice and the outer ring surface, is the drag force between the i-th slice of the j-th rolling element and the outer ring; b) The frictional heat between the rolling element and the cage pocket is , where f rcj is the friction between the rolling element and the cage pocket; c is the friction heat between the cage guide surface and the ring rib ,ω m is the cage angular velocity, M cx is the moment of the cage around the x-axis, , Z is the number of rolling elements, For the j d) the heat generated by the viscous damping of the rolling element during its motion , where F dj is the viscous resistance.

[0049] Furthermore, in the above step S5, the bearing thermal boundary conditions are constructed according to the bearing high temperature simulation test results, the bearing heat is distributed through the heat generation mechanism, the contact position thermal resistance of the test bearing is calculated under the lubricating oil lubrication condition, and the bearing thermal balance equation is established through the bearing heat distribution result and the contact position thermal resistance, including: S51, performing a high temperature simulation test on the test bearing to obtain the bearing high temperature simulation test results including the oil supply temperature, the bearing outer ring temperature and the bearing cavity temperature; S52, using the bearing high temperature simulation test result as a thermal boundary condition, and distributing heat generation according to the bearing heat generation, the bearing heat generation position, and the heat transfer ratio; S53. Under lubricating oil conditions, the thermal resistance of the contact position through which the lubricating oil flows is obtained by a thermal network method, and a bearing thermal balance equation is established by the heat distribution result and the thermal resistance of the contact position.

[0050] Furthermore, in the above step S5, the temperature rise of each part of the test bearing is obtained by iteratively solving the bearing thermal balance equation, including: The bearing thermal balance equation is iteratively solved by Gaussian elimination method and super relaxation iteration method until the result of this iteration is The result of the previous iteration The convergence accuracy of is less than a threshold value, and the temperature rise of each part of the test bearing is output.

[0051] The above steps S51 to S53 specifically include the following process: The thermal network method is used to calculate the bearing temperature distribution and establish Figure 5 The thermal network model of the aviation test bearing is shown in the figure. The definitions of each node in the thermal network model are shown in Table 1. Under high-speed conditions, for the aviation test bearing using under-ring oil supply, part of the heat generated by viscous friction is carried away by the lubricating oil, and the other part is transmitted to the surface of the rolling element. Therefore, it can be assumed that λ is the ratio of lubricating oil heat conduction to heat convection. λ is generally taken as 0.05~0.1. H f The viscous friction of the lubricating oil generates heat. H f = H rc + H ci + H d , the friction heat generated by the rolling element and the inner ring H 2 is applied to node 3 to generate heat from friction between the rolling element and the outer ring. H 1 is applied to node 5, which generates heat due to viscous friction of the lubricating oil H f Applied to node 4, another part of the lubricating oil generates heat due to viscous friction (1-λ) H f Applied to node 12.

[0052] Table 1: Definition of nodes in the thermal network model of aviation test bearings

[0053] By generalizing Ohm's law, the bearing thermal resistance equation can be established as follows: , where heat flow in the formula is heat generation. In addition, during under-ring lubrication, the lubricating oil cools the inner ring, rolling element and cage of the bearing in sequence, and finally flows to the outer ring of the bearing through the gap between the rolling element and the cage by centrifugal action. In order to simulate the influence of the order of lubricating oil cooling on the bearing temperature distribution, the lubricating oil flow process is divided into 5 nodes (i.e., node 10 to node 14), and then: , where R 10-11 , R 11-12 , R 12-13 , R 13-14 , R 14-10 They are the thermal resistances between nodes 10 and 11, between nodes 11 and 12, between nodes 12 and 13, between nodes 13 and 14, and between nodes 14 and 10, respectively. f The bearing generates heat. Thus, the node 11 conducts heat convection with the inner ring of the bearing, the node 12 conducts heat convection with the rolling elements and the cage of the bearing, and the node 13 conducts heat convection with the outer ring of the bearing.

[0054] The heat exchange of each node in the test bearing is mainly through heat conduction and heat convection. According to the structural characteristics of the bearing, the thermal resistance type of each node of the bearing is determined as shown in Table 2 below: Table 2: Thermal resistance types of aviation test bearings

[0055] According to the first law of thermodynamics, the sum of the heat flux flowing through each node is equal to 0, which means: , where H g As heat source, Q d is the heat flux through heat conduction, Q v is the heat flow via convection.

[0056] To facilitate the establishment of the temperature equation, the heat transfer coefficient is assumed to be S is the inverse of thermal resistance. For nodes that do not actually generate heat exchange, it is considered that their thermal resistance is infinite, that is, the heat transfer coefficient is 0. The final bearing thermal balance equation can be expressed as: ,in, For Node The temperature, For Node The temperature, For Node With Node is the heat transfer coefficient between nodes, and M is the total number of nodes.

[0057] The temperatures of nodes 1, 10 and 15 can be measured experimentally and used as boundary conditions of the thermal balance equation. The Gaussian elimination method is used to solve the thermal balance equation of the bearing. k The bearing temperature is obtained by step With k- Bearing temperature obtained in step 1 For comparison, if the relative error Less than the convergence precision , then the temperature of each node of the bearing is output and displayed in real time on the display. Otherwise, the super-relaxation iteration method is used to iterate the bearing temperature, and the above steps S1 to S4 are repeated until convergence.

[0058] In order to illustrate the effectiveness of the above method of the present invention, a certain type of aviation cylindrical bearing is used as an example for explanation. The structural parameters of the aviation cylindrical bearing are shown in Table 3 below: Table 3: Main parameters of a certain type of aviation cylindrical bearing

[0059] First, according to the test results of the bearing outer ring temperature, the initial temperature value of each bearing part is given as the bearing outer ring temperature, that is, , establish the bearing coordinate system, such as Figure 3 As shown, j The rolling element is divided into N slices, calculate the working clearance of the bearing at the current temperature in accordance with step S1; analyze the relationship between the rolling element load and the load-displacement between the inner ring and the outer ring in accordance with steps S2 and S3, analyze the average speed and sliding speed between the rolling element and the inner ring and the outer ring, analyze the friction force and friction torque between the bearing contact pairs, and establish a force balance equation group of the rolling element, the cage and the inner ring; calculate the friction heat of the bearing in accordance with step S4; and calculate the friction heat of the bearing in accordance with steps S5 and S6. Figure 5 The thermal network node model shown in the figure is used to iteratively calculate the temperature rise of each node in the aviation cylindrical bearing, that is, see Figure 6 The heat transfer coefficient matrix is ​​shown.

[0060] Based on the same inventive concept, an embodiment of the present invention also provides an aviation bearing temperature rise prediction system based on a high temperature test device, as described in the following embodiments. Since the principle of solving the problem by the aviation bearing temperature rise prediction system is similar to the aviation bearing temperature rise prediction method shown in the above embodiment, the implementation of the system can refer to the implementation of the aviation bearing temperature rise prediction method, and the repeated parts will not be repeated.

[0061] Figure 7It is a structural block diagram of an aviation bearing temperature rise prediction system based on a high temperature test device disclosed in an embodiment of the present invention. The aviation bearing temperature rise prediction system includes a bearing high temperature simulation test device 701, a working clearance calculation module 702, a first construction module 703, a viscous resistance calculation module 704, a second construction module 705, a bearing heat generation acquisition module 706 and a temperature rise calculation module 707. The structure is described below.

[0062] The bearing high temperature simulation test device 701 is used to perform a high temperature simulation test on the test bearing. Figure 8 As shown, the bearing high temperature simulation test device 701 includes supplying lubricating oil to the test bearing 70 and the oil retaining nut 80 by the way of under-ring oil supply, sealing the bearing cavity with a graphite seal 40, heating the test bearing by electric heating, installing 4 temperature measuring probes inside the electric heater 90, and the probe leads are led out from the first lead connector 20 and the second lead connector 30. The temperature of the heater and the temperature of the bearing support 10 are adjusted by the heat insulation cover 100 and the control system 110 to keep the peripheral temperature of the bearing relatively stable to simulate the high temperature working environment of the aviation bearing. In order to prevent oil mist from entering the electric heater 90, the outer ring of the bearing is pressed The nut and the oil retaining device are integrated, and a high-temperature sealing rubber ring is added between the heat insulation cover and the bearing support. Lubricating oil is provided to the rotor assembly 50 through the oil supply nozzle 60, thereby realizing oil supply to the test bearing 70.

[0063] The working clearance calculation module 702 is used to obtain the working clearance of the test bearing through thermodynamic theory according to the temperature of the outer ring of the bearing. Specifically, the working clearance calculation module 702 calculates the working clearance of the test bearing through the above steps S11 to S13.

[0064] The first construction module 703 is used to construct the contact load-deformation relationship and the contact load-drag force relationship. The viscous resistance calculation module 704 is used to calculate the viscous resistance borne by the rolling body according to the rolling body's revolution angular velocity and the oil-gas mixture density; the second construction module 705 is used to construct the thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation. Specifically, the first construction module 703, the viscous resistance calculation module 704 and the second construction module 705 are used to implement the above-mentioned methods of steps S22 to S24 and steps S31 to S34.

[0065] The bearing heat generation acquisition module 706 is used to iteratively solve the bearing pseudo-dynamic load force balance equation and calculate the bearing heat generation according to the iterative solution result. Specifically, the bearing heat generation acquisition module 706 is used to calculate the bearing heat generation through steps S41 and S42.

[0066] The temperature rise calculation module 707 is used to construct the bearing thermal boundary conditions according to the bearing high temperature simulation test results, distribute the bearing heat through the heat generation mechanism, calculate the contact position thermal resistance of the test bearing under the lubricating oil lubrication condition, establish the bearing thermal balance equation through the bearing heat distribution result and the contact position thermal resistance, and iteratively solve the bearing thermal balance equation to obtain the temperature rise of each part of the bearing. Specifically, the temperature rise calculation module 707 is used to calculate the temperature rise of each part of the test bearing, that is, the temperature rise of each node, through step S5.

[0067] The method of the present invention simulates the high-temperature working state of aviation bearings, considers the influence of thermal conditions on bearing clearance, load distribution, speed distribution and lubrication characteristics during bearing operation, and proposes a bearing temperature rise prediction method based on the thermal-fluid-solid coupling effect according to the heat distribution law and heat exchange law inside the bearing. Based on this method, rapid iterative optimization of aviation bearing structure can be achieved, and a more accurate theoretical basis can be provided for the selection of the matching between bearings and shafts and bearing seats, so as to realize the temperature rise test assessment of aviation bearings under high temperature environment. This method has the following advantages: 1) The test simulation device can simulate the high temperature working environment of the aircraft bearing. It uses electric heating to directly heat the peripheral temperature of the bearing. The heating speed is fast and the temperature control accuracy is high, which is convenient for test implementation. The test results are as follows: Figure 2 As shown, it provides an accurate thermal boundary for the temperature field analysis of aviation bearings under high temperature conditions; 2) This method takes into account the influence of thermal-mechanical conditions on the bearing load characteristics and the influence of the lubrication state of each contact pair on the bearing motion characteristics. Combined with the heat distribution law and heat exchange law inside the aviation bearing, it obtains more accurate bearing heat generation and temperature rise under the condition of thermal-fluid-solid coupling. It can quickly and accurately obtain the bearing temperature distribution during the bearing structure optimization design, providing a more accurate and reasonable basis for the selection of bearing matching parameters and external oil supply parameters. 2) This method is easy to implement in a process-based manner and can be compiled into a modular calculation program. Combined with the results of high-temperature simulation tests on bearings, it can realize real-time temperature rise prediction of aviation bearings in high-temperature environments, provide support for temperature rise test assessment of bearings in high-temperature environments other than engine whole-machine tests, and reduce test costs.

[0068] In this embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, any of the above-mentioned methods for predicting the temperature rise of an aviation bearing based on a high temperature test device is implemented. Specifically, the computer device may be a computer terminal, a server, or a similar computing device.

[0069] In this embodiment, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program for executing any of the above-mentioned aviation bearing temperature rise prediction methods based on a high temperature test device. Specifically, the computer-readable storage medium includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. The information can be a computer-readable instruction, a data structure, a module of a program, or other data. Examples of computer-readable storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable storage media does not include temporary computer-readable media (transitory media), such as modulated data signals and carriers.

[0070] Obviously, those skilled in the art should understand that the modules or steps of the above-mentioned embodiments of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, and optionally, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order from that here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. In this way, the embodiments of the present invention are not limited to any specific combination of hardware and software.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting temperature rise of aviation bearings based on a high temperature test device, characterized in that: include: The test bearing is heated to collect the temperature of the outer ring of the bearing, and the temperature of the outer ring of the bearing is used as the initial working temperature of each part of the bearing. The working clearance of the test bearing is obtained by using the temperature of the outer ring of the bearing, the structural parameters and the material parameters of the test bearing through the theory of thermodynamics; A contact load-deformation relationship between the rolling element and the raceway of the ferrule is established according to the bearing coordinate system, the working clearance and the oil film thickness, a contact load-drag force relationship between the rolling element and the raceway of the ferrule is established under a given bearing inner ring speed condition, and the viscous resistance borne by the rolling element is calculated according to the rolling element's revolution angular velocity and the density of the oil-gas mixture; According to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and moment between the rolling element and the cage pocket, the force and moment between the cage and the guide ring, and the inertia force and moment of the rolling element, a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation is constructed; Iteratively solving the pseudo-dynamic load force balance equation of the bearing, and calculating the heat generation of the bearing according to the iterative solution result; The bearing thermal boundary conditions are constructed according to the results of the high-temperature simulation test of the bearing, the heat generated by the bearing is distributed through the heat generation mechanism, the thermal resistance at the contact position of the test bearing is calculated under the condition of lubricating oil lubrication, the bearing thermal balance equation is established through the bearing heat distribution results and the contact position thermal resistance, and the bearing thermal balance equation is iteratively solved to obtain the temperature rise of each part of the bearing.

2. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: The test bearing is heated to collect the bearing outer ring temperature, the bearing outer ring temperature is used as the initial working temperature of each part of the bearing, and the working clearance of the test bearing is obtained by using the bearing outer ring temperature, the structural parameters and material parameters of the test bearing through the thermodynamic theory, including: The test bearing is heated to collect the temperature of the outer ring of the bearing, and the temperature of the outer ring of the bearing is used as the initial working temperature of the rotating shaft, inner ring, rolling element, outer ring and bearing seat in the test bearing; According to thermodynamic theory, the thermal expansion coefficient, the diameter of the parts, the ambient temperature and the initial working temperature are used to calculate the thermal expansion of the inner ring, the rolling element and the outer ring respectively, and the clearance reduction under the temperature condition is calculated according to the thermal expansion; The working clearance of the test bearing is calculated based on the initial bearing clearance, the clearance reduction under the speed condition, the clearance reduction under the matching condition and the clearance reduction under the temperature condition.

3. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: The contact load-deformation relationship between the rolling element and the ring raceway is constructed based on the bearing coordinate system, the working clearance, the load and the oil film thickness, including: Establishing the bearing coordinate system, the bearing coordinate system includes an inertial coordinate system with the center of the outer ring of the test bearing as the origin, an inner ring coordinate system with the center of the inner ring as the origin, and an azimuth coordinate system with the center of each rolling element as the origin; Dividing each rolling element into a plurality of slices along the length direction of the rolling element by a slicing method, and establishing the relationship between the oil film thickness and the deformation between the slice and the raceway of the ring according to the working clearance and the oil film thickness; The average slice speed and the slice sliding speed of the slice and the ring raceway are calculated according to the inertial coordinate system, the inner ring coordinate system and the azimuth coordinate system by using the angular velocity of the ring, the distance between the slice and the ring, the orbital angular velocity of the rolling body and the rotational angular velocity of the rolling body, and the relationship between the oil film thickness and the contact load between the slice and the ring raceway is established according to the average slice speed through the line contact elastohydrodynamic lubrication theory; Through the relationship between the oil film thickness and the deformation and the relationship between the oil film thickness and the contact load, a contact load-deformation relationship between the rolling element and the ring raceway is constructed according to the Hertz contact theory.

4. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 3 is characterized in that: The expression of the relationship between the oil film thickness and deformation is: ,in, For the j Rolling element i On a slice The distance between point φ and point P on the ferrule surface, For the j The deformation between the i-th slice of the rolling element and the ring, is the deformation caused by the rolling element convexity on the i-th slice, is the deviation angle of the bearing inner ring axis relative to the bearing outer ring axis, is the bearing angular position, is the oil film thickness between the ith slice of the jth rolling element and the ring, i is the slice number representing the ith slice, w is the slice thickness, P d It is the working clearance of the bearing; The expression of the relationship between the oil film thickness and the contact load is: ,in, For the j Rolling element i The average speed of the slices and the ring, is the equivalent elastic modulus of the rolling element and the outer ring, is the equivalent radius of curvature of the rolling element and the ring, is the oil viscosity, is the viscosity-pressure coefficient, Q ji For the j Rolling element i The contact load between the slice and the ring, L r is the rolling element length, is the oil film correction factor considering thermal effects.

5. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: The expression of the contact load-drag force relationship is: ,in, is the drag force between the ith slice and the ring in the jth rolling element, Q ji is the contact load of the i-th slice in the j-th rolling element, is the friction coefficient between the rolling element and the raceway of the ferrule.

6. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: The formula for calculating the viscous resistance of the rolling element based on the rolling element's orbital angular velocity and the density of the oil-gas mixture is: , where F dj is the viscous resistance, D m is the bearing pitch diameter, ρ ef is the density of oil-gas mixture, C D is the damping coefficient, D w is the rolling element diameter, is the rolling body revolution angular velocity of the jth rolling body.

7. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: According to the contact load-deformation relationship, the contact load-drag force relationship, the viscous resistance, the force and moment between the rolling element and the cage pocket, the force and moment between the cage and the guide ring, and the inertia force and moment of the rolling element, a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation is constructed, including: According to the long sliding bearing model, the force and torque between the rolling element and the cage pocket are obtained; according to the short sliding bearing model, the force and torque between the cage and the guide ring are obtained; and according to theoretical mechanics, the rolling element inertia force and torque when the test bearing rotates are obtained; According to the force and moment between the rolling element and the cage pocket, the inertia force and moment of the rolling element, the contact load-deformation relationship and the viscous resistance, a force balance equation and a moment balance equation of the rolling element under thermal-fluid-solid coupling are established; In steady-state operation, the cage rotation speed is taken as a constant value as a constraint condition, and according to the force and torque between the cage and the guide ring, a force balance equation and a torque balance equation of the cage with thermal-fluid-solid coupling are established; Under given external load conditions, according to the contact load-deformation relationship and the contact load-drag force relationship, the force balance equation and torque balance equation of the inner ring of the thermal-fluid-solid coupling are established to complete the construction of the pseudo-dynamic load force balance equation of the bearing.

8. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 1, characterized in that: According to the results of the high-temperature simulation test of the bearing, the thermal boundary conditions of the bearing are constructed, the heat generated by the bearing is distributed through the heat generation mechanism, the thermal resistance at the contact position of the test bearing is calculated under the lubricating oil lubrication condition, and the thermal balance equation of the bearing is established through the heat distribution results of the bearing and the thermal resistance at the contact position, including: Performing a high temperature simulation test on the test bearing to obtain the bearing high temperature simulation test results including the oil supply temperature, the bearing outer ring temperature and the bearing cavity temperature; The high temperature simulation test results of the bearing are used as thermal boundary conditions, and heat generation distribution is performed according to the heat generation of the bearing, the heat generation position of the bearing, and the heat transfer ratio; Under lubricating oil conditions, the thermal resistance of the contact position through which the lubricating oil flows is obtained by the thermal network method, and the bearing thermal balance equation is established by the heat distribution result and the thermal resistance of the contact position.

9. The method for predicting temperature rise of aviation bearings based on a high temperature test device according to claim 8, characterized in that: The bearing heat balance equation is iteratively solved to obtain the temperature rise of each part of the test bearing, including: The bearing thermal balance equation is iteratively solved by Gaussian elimination method and super relaxation iteration method until the result of this iteration is The result of the previous iteration The convergence accuracy of is less than a threshold value, and the temperature rise of each part of the test bearing is output.

10. An aviation bearing temperature rise prediction system based on a high temperature test device, characterized in that: include: A bearing high temperature simulation test device, the bearing high temperature simulation test device is used to perform a high temperature simulation test on the test bearing; A working clearance calculation module, which is used to obtain the working clearance of the test bearing through thermodynamic theory according to the temperature of the outer ring of the bearing; A first building module, the first building module is used to build a contact load-deformation relationship and a contact load-drag force relationship; A viscous resistance calculation module, which is used to calculate the viscous resistance borne by the rolling body according to the rolling body's revolution angular velocity and the density of the oil-gas mixture; A second building block, the second building block is used to build a thermal-fluid-solid coupled bearing pseudo-dynamic load force balance equation; A bearing heat generation acquisition module, the bearing heat generation acquisition module is used to iteratively solve the bearing pseudo-dynamic load force balance equation and calculate the bearing heat generation according to the iterative solution result; A temperature rise calculation module is used to construct a bearing thermal boundary condition according to the bearing high temperature simulation test results, distribute the bearing heat through the heat generation mechanism, calculate the contact position thermal resistance of the test bearing under oil lubrication conditions, establish a bearing thermal balance equation through the bearing heat distribution results and the contact position thermal resistance, and iteratively solve the bearing thermal balance equation to obtain the temperature rise of each part of the bearing.

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