Bearing temperature distribution calculation method and system based on full-node thermal network model

Abstract

The invention discloses a bearing temperature distribution calculation method and system based on a full-node thermal network model. The method comprises the following steps that material parameters, size parameters, working conditions and lubrication parameters of a bearing are obtained; calculating real-time motion parameters and mechanical parameters based on the bearing kinetic model; calculating a real-time internal heat source of the bearing according to the real-time motion and mechanical parameters obtained in the step S2; dividing hot nodes based on a bearing structure; according to the heat conduction and convection effect between the parts of the bearing, calculating the thermal resistance between the heat nodes; constructing a bearing full-node thermal network model according to the real-time internal heat source, the thermal node and the thermal resistance of the bearing; and based on the bearing full-node thermal network model, calculating the temperature of each thermal node to obtain the temperature distribution of the whole bearing. By adopting the technical scheme, the bearing temperature distribution condition and the local temperature value based on the load distribution of the rolling body are obtained based on the full-node thermal network model.

Description

Technical Field

[0001] The present invention belongs to the technical field of rolling bearings and relates to a bearing temperature distribution calculation method and system based on a full-node thermal network model. Background Art

[0002] Rolling bearings are critical components in rotating machinery, and their health directly impacts the reliability and stability of the entire machine. As bearings rotate, friction between components inevitably generates frictional heat, causing the bearing temperature to rise. Temperature rise is a key factor influencing bearing operation. Excessively high bearing temperatures can lead to poor internal lubrication, causing burns and adhesion on the raceway surface, exacerbating wear and fatigue spalling between the rolling elements and raceways, and ultimately leading to bearing failure.

[0003] When a bearing is subjected to radial loads, especially heavy loads, frictional heat generated in the loaded area is much greater than in the unloaded area. When the bearing rings are installed skewed or subjected to deflection torque, frictional heat generated in the unloaded area is greater than in the areas on either side. Both of these conditions can cause excessive localized bearing temperature rise, resulting in localized bearing damage and endangering bearing health.

[0004] Currently, bearing temperature distribution is primarily determined through experimental measurement and finite element simulation. Experimental measurement typically involves placing multiple temperature sensors outside the bearing rings to obtain discrete temperature distributions, or using annular temperature sensors to obtain continuous temperature distributions. However, sensor installation requires drilling or slotting in the shaft or bearing seat, which damages the mechanical structure and is costly.

[0005] Finite element simulation is divided into static analysis and dynamic analysis. Static analysis can obtain the bearing temperature in steady state but ignores the impact of the bearing's real-time operating status on the bearing temperature rise. Although dynamic analysis integrates the bearing's operating status, it requires thermal-solid joint simulation, which has high computational costs.

[0006] Existing numerical analysis methods for bearing temperature primarily approximate the bearing rings and cage as thin-walled rings, connect the rolling elements in parallel, and construct thermal network models in the radial and axial planes to determine the overall bearing temperature. Because these methods ignore the circumferential heat transfer effect, they are unable to determine the circumferential temperature distribution of the bearing and cannot calculate the local temperature rise of the bearing. Summary of the Invention

[0007] The purpose of the present invention is to provide a bearing temperature distribution calculation method and system based on a full-node thermal network model to obtain the bearing temperature distribution status and local temperature values ​​based on the rolling element load distribution.

[0008] In order to achieve the above object, the basic scheme of the present invention is: a method for calculating bearing temperature distribution based on a full-node thermal network model, comprising the following steps:

[0009] S1, obtaining the material parameters, size parameters, working conditions and lubrication parameters of the bearing;

[0010] S2, calculates real-time motion parameters and mechanical parameters based on the bearing dynamics model;

[0011] S3, calculating the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2;

[0012] S4, divides multiple thermal nodes based on the bearing structure;

[0013] S5, calculating the thermal resistance between each thermal node divided in step S4 based on the heat conduction and convection effects between the various components of the bearing;

[0014] S6, constructs a full-node thermal network model of the bearing based on the real-time internal heat sources, thermal nodes, and thermal resistance of the bearing;

[0015] S7, based on the bearing full-node thermal network model, calculate the temperature of each thermal node divided in step S4 to obtain the entire bearing temperature distribution.

[0016] The working principle and beneficial effects of this basic solution are: this technical solution is based on a full-node thermal network model, taking into account the heat transfer effect in the circumferential direction of the bearing and the local heat generation that changes with the dynamic characteristics of the bearing, and can obtain the bearing temperature distribution status and local temperature values ​​based on the load distribution of the rolling elements.

[0017] The present invention is described using angular contact ball bearings as an example, but is not limited thereto. The method can be adjusted according to the type of bearing, and the nodes of the thermal network model of the present invention can be divided more finely according to specific circumstances.

[0018] Furthermore, in step S2, the method for calculating the real-time motion parameters and mechanical parameters based on the bearing dynamics model is:

[0019] The bearing dynamics model uses a complete dynamics model to calculate real-time motion parameters, including:

[0020] Rolling element rotation speed ω b ={ω x ,ω y ,ω z} T , where ω x ,ω y ,ω z are the rotation components of the x, y, and z axes of the coordinate system respectively;

[0021] Rolling element revolution speed ω m 、Cage speed ω c 、Inside and outside sliding speed v={v i ,ve} T ;

[0022] Internal and external contact angles α = {α i ,α e} T , where α i ,α e Indicates internal contact angle and external contact angle, subscript i stands for internal and e stands for external;

[0023] Computational mechanical parameters, including:

[0024] Drag friction force F in the direction of the major axis of the inner and outer contact ellipses Ta ={F Tai ,F Tae} T , where F Tai Indicates the drag friction force in the direction of the major axis of the inner contact ellipse, F Tae is the drag friction force in the direction of the major axis of the external contact ellipse;

[0025] Drag friction force F in the minor axis direction Tb ={F Tbi ,F Tbe} T , where F Tbi is the drag friction force in the direction of the minor axis of the inner contact ellipse, F Tbe is the drag friction force in the direction of the minor axis of the external contact ellipse;

[0026] Internal and external Hertz contact force N = {N i ,N e} T , where N i ,N e They are internal contact force and external contact force respectively;

[0027] Internal and external spin friction torque M S ={M si ,M se} T , where M si ,M se They are the inner spin friction torque and the outer spin friction torque respectively;

[0028] The resistance F of the rolling element to the movement of the oil and gas lubricant D ; Rolling and sliding fluid dynamic pressure friction force F between the long and short axis entrance areas of the cage pocket and the rolling element contact surface Ra 、F Rb 、F Sa 、F Sb ; Fluid dynamic friction torque M between the cage and the guide ring cx .

[0029] Based on the bearing dynamics model, real-time motion parameters and mechanical parameters are obtained, which is convenient for use.

[0030] Furthermore, step S3 calculates the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2. The specific steps are as follows:

[0031] Calculates local power losses in bearings, including:

[0032] Rolling elastic hysteresis power loss Q 1j :

[0033]

[0034] in,

[0035]

[0036] Among them, α h is the elastic hysteresis coefficient, d m is the bearing pitch diameter, j is the jth rolling element, and there are N b rolling elements; the subscripts i and e represent the inner ring and outer ring respectively, w is the rolling element diameter, α0 is the initial contact angle, K(e) is the first kind of elliptic integral, L(e) is the second kind of elliptic integral, a is the major semi-axis of the contact ellipse, b is the minor semi-axis of the contact ellipse, ∑ρ is the sum of the principal curvatures of the contact point between the rolling element and the ring, E′ is the equivalent elastic modulus of the two contacting objects; γ0 is a dimensionless parameter, Γ j is the intermediate parameter, ω bj is the rotation speed of the jth rolling element, N is the internal and external Hertz contact force;

[0037] Differential sliding friction power loss Q 2j :

[0038] Q 2j =F Tb v

[0039] Among them, F Tb is the drag friction force in the direction of the minor axis, and v is the internal and external sliding speed of the rolling element;

[0040] Spin-sliding friction power loss Q 3j :

[0041] Q 3j =M s ω s

[0042] Among them, M s is the internal and external spin friction torque, ω s is the spin speed:

[0043] ωs =(ω-ω m )sinα+ω b sin(α-β)

[0044] Among them, ω is the speed of the inner and outer rings, β is the attitude angle; α is the inner and outer contact angle, ω m is the rolling element revolution speed, ω b is the rolling element rotation speed;

[0045] Gyroscope friction power loss Q 4j :

[0046]

[0047] Among them, F Ta is the drag friction force in the direction of the minor axis; ω z is the rotation component of the coordinate system z-axis;

[0048] Steel ball lubrication drag friction power loss Q 5j :

[0049]

[0050] Among them, F D It is the resistance of oil and gas lubricant to the movement of rolling elements;

[0051] Friction power loss Q between cage pocket and steel ball 6j :

[0052]

[0053] Among them, F Ra 、F Rb 、F Sa 、F Sb Respectively represent the rolling and sliding fluid dynamic pressure friction forces in the long and short axis entrance areas of the contact surface between the cage pocket and the rolling element; ω x ,ω y is the rotation component of the x and y axes of the coordinate system;

[0054] Sliding friction power loss Q between the cage and the guide surface 7j :

[0055] Q 7j =M cx (ω l -ω c )

[0056] Among them, ω l is the speed of the guide ring; M cx Represents the hydrodynamic friction torque between the cage and the guide ring; ω c is the cage speed;

[0057] Assuming that all power loss is converted into heat generated by the bearing, the internal heat source of the bearing is concentrated in the contact area between the rolling element and the ring and the contact area between the rolling element and the cage. The heat generated in each area is:

[0058]

[0059] Among them, H inner is the heat of the contact area between the rolling element and the inner ring, H outer is the heat of the contact area between the rolling element and the outer ring, H pocket It is the heat of the contact area between the rolling element and the cage.

[0060] According to the real-time motion and dynamic parameters obtained in S2, the real-time internal heat source of the bearing is obtained.

[0061] Furthermore, step S4 divides the thermal nodes based on the bearing structure, specifically:

[0062] S401, divide the bearing into N according to the number of rolling elements b Each area contains a rolling element, inner and outer ring segments and a cage segment;

[0063] S402, determine the thermal node conditions of each area in step S401, and divide it into 7 nodes in total, node 1 is the inner ring and shaft matching surface, node 2 is the rolling element and inner ring contact area, node 3 is the rolling element center of mass, node 4 is the rolling element and outer ring contact area, node 5 is the outer ring and bearing group matching surface, node 6 and node 7 are the front and rear collision surfaces between the rolling element and the cage pocket; the bearing area has a total of 7N b Hot nodes;

[0064] S403, determine the thermal nodes of the non-bearing area. There are four thermal nodes in the non-bearing area: node 8 is the center of the shaft that cooperates with the bearing, node 9 is the outer surface of the bearing seat that cooperates with the bearing, node O is the lubricating oil gas, and node A is the air node.

[0065] Combining the bearing structure with specific conditions, thermal nodes are divided to facilitate targeted temperature collection.

[0066] Furthermore, in step S5, the method for calculating the thermal resistance between the thermal nodes divided in step S4 is as follows based on the heat conduction and convection effects between the various components of the bearing:

[0067] S501, calculates radial thermal resistance, including:

[0068] Thermal resistance R from the inner surface of the inner ring to the contact area 12 :

[0069]

[0070] Among them, d i is the inner raceway diameter, d is the bearing inner diameter, k i is the thermal conductivity of the inner ring, B is the width of the inner ring; N b is the number of rolling elements;

[0071] Thermal resistance R from the contact area between the inner ring and the rolling element to the center of the rolling element 23 :

[0072]

[0073] Among them, k b is the thermal conductivity of the rolling element, α b is the thermal diffusivity; b i is the semi-minor axis of the inner contact ellipse, v i is the speed of the rolling element relative to the inner raceway, a i is the semi-major axis of the inner contact ellipse;

[0074] Thermal resistance R from the contact area between the outer ring and the rolling element to the center of the rolling element 34 :

[0075]

[0076] Among them, b e is the minor semi-axis of the external contact ellipse, v e is the speed of the rolling element relative to the outer raceway, a e is the semi-major axis of the outer contact ellipse;

[0077] Thermal resistance R from the outer surface of the outer ring to the contact area 45 :

[0078]

[0079] Where D is the outer diameter of the bearing, D e is the outer channel diameter, k e is the thermal conductivity of the outer ring, C is the width of the outer ring;

[0080] Thermal resistance R from the inner surface of the inner ring to the center of the axis 18 :

[0081]

[0082] Among them, k s is the thermal conductivity of the shaft;

[0083] Thermal resistance R from the outer surface of the outer ring to the surface of the bearing seat 59 :

[0084]

[0085] Among them, D his the bearing seat surface diameter, k h is the thermal conductivity of the bearing seat;

[0086] S502, calculate the axial thermal resistance, including:

[0087] Thermal resistance R from shaft center to shaft end ′ 8A :

[0088]

[0089] Among them, L s is the distance from the shaft center to the shaft end;

[0090] Thermal resistance R from the bearing seat to the end face ′ 9Aa :

[0091]

[0092] Among them, L h The distance from the fitting point between the bearing seat and the bearing to the end face;

[0093] 503, calculation of circumferential thermal resistance, including:

[0094] Thermal resistance R between adjacent inner ring segments 22 :

[0095]

[0096] Thermal resistance R between adjacent outer ring segments 44 :

[0097]

[0098] Thermal resistance R from the center of the rolling element to the collision surface with the front and rear cage pockets 36 、R 37 :

[0099]

[0100] Among them, D c is the outer diameter of the cage, d c is the inner diameter of the cage;

[0101] Thermal resistance R between the front and rear pockets of adjacent cage segments 67 :

[0102]

[0103] Among them, k c is the thermal conductivity of the cage;

[0104] 504, Calculate the heat transfer resistance between bearings and lubricating oil and gas, including:

[0105] Thermal resistance R between rolling element and lubricating oil and gas 6O , R 7O :

[0106]

[0107] Among them, the rolling element heat transfer coefficient

[0108] Rolling element Reynolds number Pelectric number of lubricating oil and gas

[0109] k eff is the thermal conductivity of the oil-gas mixture, ρ eff is the density of the oil-gas mixture, μ eff is the dynamic viscosity of the oil-gas mixture; D w is the rolling element diameter; d m is the bearing pitch diameter; ω m is the rolling element revolution speed;

[0110] Heat transfer resistance R between the inner ring and lubricating oil and gas 2O :

[0111]

[0112] Among them, the heat transfer coefficient of the inner ring section is

[0113] Nusselt number Reynolds number

[0114] Heat transfer resistance R between outer ring segment and lubricating oil and gas 4O :

[0115]

[0116] Among them, the heat transfer coefficient of the outer ring section is

[0117] Nusselt number Reynolds number d i is the inner raceway diameter, d e is the outer raceway diameter;

[0118] 505, calculate the heat transfer resistance between the shaft and bearing seat and the air, including:

[0119] Forced convection thermal resistance R″ between the shaft end and the air 8A :

[0120]

[0121] Among them, the heat transfer coefficient of the shaft end is

[0122] Nusselt number

[0123] Reynolds number Prair is the air Pelect number; k air is the thermal conductivity of air, μ air is the air dynamic viscosity;

[0124] Natural convection thermal resistance R between the outer surface of the bearing seat and the air 9Ar :

[0125]

[0126] Among them, h h is the natural flow coefficient between the bearing seat and the air, L h is the bearing seat length;

[0127] Natural convection thermal resistance R″ between the bearing seat end face and air 9Aa :

[0128]

[0129] 506. Calculate the equivalent thermal resistance between the air node and the non-bearing area based on the series-parallel relationship:

[0130] R 8A =R′ 8A +R″ 8A

[0131] R 9Aa =R ′ 9Aa +R″ 9Aa

[0132]

[0133] Among them, R 8A is the thermal resistance between the shaft and the air node, R 9Aa is the axial thermal resistance between the bearing seat and the air node, R 9A is the comprehensive thermal resistance between the bearing seat and the air node.

[0134] The corresponding thermal resistance is calculated based on the relationship between heat conduction and heat convection during bearing operation, which is easy to operate.

[0135] Furthermore, in step S6, a method for constructing a full-node thermal network model of the bearing based on the real-time internal heat sources, thermal nodes, and thermal resistance of the bearing is as follows:

[0136] Assuming that the air node A and the lubricating oil node O are constant temperature nodes, the heat flow balance equation of the bearing area is established. The heat flow balance equation of the j-th bearing area contains:

[0137] Node 1:

[0138]

[0139] Node 2:

[0140]

[0141] Node 3:

[0142]

[0143] Node 4:

[0144]

[0145] Node 5:

[0146]

[0147] Node 6:

[0148]

[0149] Node 7:

[0150]

[0151] The bearing area has a total of 7N b Balanced equations, j = 1 ~ N b , N b is the number of rolling elements; Where T is temperature, superscript j is the jth rolling element, and subscript numbers are nodes; H pocket is the heat of the contact area between the rolling element and the cage;

[0152] Establish the heat flow balance equation in the non-bearing area. Node 8 has a heat transfer relationship with air node A and N b The heat conduction occurs at node 1 on the outer surface of the bearing end, and the heat flow balance equation is:

[0153]

[0154] Where T8 represents the temperature of node 8, T A represents the temperature of node A;

[0155] Node 9 has a heat transfer relationship with air node A and also with N bThe heat conduction occurs at the node 5 on the outer surface of the bearing end, and the heat flow balance equation is:

[0156]

[0157] There are two equilibrium equations in the non-bearing area, where T9 represents the temperature of node 9.

[0158] According to the law of conservation of heat, the heat flow balance equation of each node is established to form a complete thermal network model.

[0159] Furthermore, step S7 calculates the temperature of each thermal node divided in step S4 based on the bearing full-node thermal network model to obtain the entire bearing temperature distribution. The specific steps are as follows:

[0160] Rewrite all the heat flow balance equations in step S6 into the form of a non-homogeneous linear equation system:

[0161] A·T=H,

[0162] The unknown vector is represented as:

[0163]

[0164] Total M = 7N b +2 elements, N b is the number of rolling elements;

[0165] The coefficient matrix AA is:

[0166]

[0167] in, If there is no thermal effect between two thermal nodes, the thermal resistance is +∞; a pq is the matrix element, p, q and k are the element position numbers, R p，k , R p，q is the corresponding thermal resistance, is the deformation of the rewritten matrix form; M is the total number of unknown vector elements;

[0168] The elements of the constant term vector H are zero when there is no heat source and are the calculated heat generation when there is a heat source;

[0169] Solve the equations, get the temperature value of each node, and find the temperature distribution.

[0170] Obtain the temperature of each divided node and obtain the temperature distribution of the entire bearing.

[0171] The present invention also provides a bearing temperature distribution calculation system based on a full-node thermal network model, comprising a data acquisition module and a processing module, wherein the data acquisition module is used to obtain material parameters, dimensional parameters, operating conditions, and lubrication parameters of the bearing and transmit them to the processing module;

[0172] The processing module executes the method of the present invention to calculate the bearing temperature distribution.

[0173] The system uses a data acquisition module and a processing module to collect relevant parameters and obtain the bearing temperature distribution and local temperature values ​​based on the rolling element load distribution. BRIEF DESCRIPTION OF THE DRAWINGS

[0174] Figure 1 1 is a flow chart of a method for calculating bearing temperature distribution based on a full-node thermal network model according to the present invention;

[0175] Figure 2 Schematic diagram of the structure of the bearing area division of the bearing temperature distribution calculation method based on the full-node thermal network model of the present invention;

[0176] Figure 3 Schematic diagram of the distribution of thermal nodes and thermal resistances in the jth region of a bearing according to the bearing temperature distribution calculation method based on the full-node thermal network model of the present invention;

[0177] Figure 4 Schematic diagram of the distribution of thermal nodes and thermal resistance in the non-bearing area of ​​the bearing temperature distribution calculation method based on the full-node thermal network model of the present invention;

[0178] Figure 5 2. It is a schematic diagram of the connection of thermal nodes in various regions of a bearing in series according to the bearing temperature distribution calculation method based on the full-node thermal network model of the present invention;

[0179] Figure 6 Schematic diagram of the connection of thermal nodes in parallel between the bearing regions and the non-bearing regions in the bearing temperature distribution calculation method based on the full-node thermal network model of the present invention;

[0180] Figure 7 This is a bearing temperature distribution diagram that changes with load based on the bearing temperature distribution calculation method of the present invention based on the full-node thermal network model. DETAILED DESCRIPTION

[0181] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0182] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0183] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal communication between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0184] The present invention discloses a method for calculating bearing temperature distribution based on a full-node thermal network model. Based on the full-node thermal network model, the bearing circumferential heat transfer effect and the local heat generation that changes with the dynamic characteristics of the bearing are considered, and the bearing temperature distribution and local temperature values ​​based on the rolling element load distribution can be obtained. Figure 1 As shown in FIG, the bearing temperature distribution calculation method based on the full-node thermal network model includes the following steps:

[0185] S1, obtain the material parameters, dimensional parameters, operating conditions and lubrication parameters of the bearing. The bearing is mainly composed of four components: an inner ring, an outer ring, a rolling element and a cage. The material parameters include the elastic modulus, Poisson's ratio, thermal conductivity, thermal expansion coefficient, etc. of the bearing components. The dimensional parameters involve the appearance characteristics of all bearing components. The operating conditions include the shaft speed supported by the bearing and the external load borne by the bearing. The lubrication parameters include the dynamic viscosity, density, thermal conductivity, viscosity-temperature coefficient, constant-pressure specific heat capacity, etc. of the lubricating oil.

[0186] S2, calculates real-time motion parameters and mechanical parameters based on the bearing dynamics model;

[0187] S3, calculating the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2;

[0188] S4, based on the bearing structure, divide multiple thermal nodes (such as Figure 2 As shown, the nodes of the thermal network model of the present invention can be divided more finely according to specific circumstances);

[0189] S5, calculating the thermal resistance between each thermal node divided in step S4 based on the heat conduction and convection effects between the various components of the bearing;

[0190] S6, based on the real-time internal heat sources, thermal nodes and thermal resistance of the bearing, considering the circumferential direction of the bearing, constructs a full-node thermal network model of the bearing;

[0191] S7, based on the bearing full-node thermal network model, calculate the temperature of each thermal node divided in step S4 to obtain the entire bearing temperature distribution.

[0192] In a preferred embodiment of the present invention, in step S2, the method for calculating the real-time motion parameters and mechanical parameters based on the bearing dynamics model is:

[0193] The bearing dynamics model uses a complete dynamics model to calculate real-time motion parameters, including:

[0194] Rolling element rotation speed ω b ={ω x ,ω y ,ω z} T , where ω x ,ω y ,ω z are the rotation components of the x, y, and z axes of the coordinate system respectively;

[0195] Rolling element revolution speed ω m 、Cage speed ω c 、Inside and outside sliding speed v={v i ,v e} T ;

[0196] Internal and external contact angles α = {α i ,α e} T , where α i ,α e Indicates internal contact angle and external contact angle, subscript i stands for internal and e stands for external;

[0197] Computational mechanical parameters, including:

[0198] Drag friction force F in the direction of the major axis of the inner and outer contact ellipses Ta ={F Tai ,F Tae} T , where F Tai Indicates the drag friction force in the direction of the major axis of the inner contact ellipse, F Tae is the drag friction force in the direction of the major axis of the external contact ellipse;

[0199] Drag friction force F in the minor axis direction Tb ={F Tbi ,F Tbe} T , where F Tbi is the drag friction force in the direction of the minor axis of the inner contact ellipse, FTbe is the drag friction force in the direction of the minor axis of the external contact ellipse;

[0200] Internal and external Hertz contact force N = {N i ,N e} T , where N i ,N e They are internal contact force and external contact force respectively;

[0201] Internal and external spin friction torque M S ={M si ,M se} T , where M si ,M se They are the inner spin friction torque and the outer spin friction torque respectively;

[0202] The resistance F of the rolling element to the movement of the oil and gas lubricant D ; Rolling and sliding fluid dynamic pressure friction force F between the long and short axis entrance areas of the cage pocket and the rolling element contact surface Ra 、F Rb 、F Sa 、F Sb ; Fluid dynamic friction torque M between the cage and the guide ring cx .

[0203] In a preferred embodiment of the present invention, step S3 calculates the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2. The specific steps are:

[0204] Calculates local power losses in bearings, including:

[0205] Rolling elastic hysteresis power loss Q 1j :

[0206]

[0207] in,

[0208]

[0209] Among them, α h is the elastic hysteresis coefficient, d m is the bearing pitch diameter, j is the jth rolling element, and there are N b rolling elements; the subscripts i and e represent the inner ring and outer ring respectively, wis the rolling element diameter, α0 is the initial contact angle, K(e) is the first kind of elliptic integral, L(e) is the second kind of elliptic integral, a is the major semi-axis of the contact ellipse, b is the minor semi-axis of the contact ellipse, ∑ρ is the sum of the principal curvatures of the contact point between the rolling element and the ring, E′ is the equivalent elastic modulus of the two contacting objects; γ0 is a dimensionless parameter, Γ j is the intermediate parameter, ω bj is the rotation speed of the jth rolling element, N is the internal and external Hertz contact force;

[0210] Differential sliding friction power loss Q 2j :

[0211] Q 2j =F Tb v

[0212] Among them, F Tb is the drag friction force in the direction of the minor axis, and v is the internal and external sliding speed of the rolling element;

[0213] Spin-sliding friction power loss Q 3j :

[0214] Q 3j =M s ω s

[0215] Among them, M s is the internal and external spin friction torque, ω s is the spin speed:

[0216] ω s =(ω-ω m )sinα+ω b sin(α-β)

[0217] Among them, ω is the speed of the inner and outer rings, β is the attitude angle; α is the inner and outer contact angle, ω m is the rolling element revolution speed, ω b is the rolling element rotation speed;

[0218] Gyroscope friction power loss Q 4j :

[0219]

[0220] Among them, F Ta is the drag friction force in the direction of the minor axis; ω z is the rotation component of the coordinate system z-axis;

[0221] Steel ball lubrication drag friction power loss Q 5j :

[0222]

[0223] Among them, F D It is the resistance of oil and gas lubricant to the movement of rolling elements;

[0224] Friction power loss Q between cage pocket and steel ball 6j :

[0225]

[0226] Among them, F Ra 、F Rb 、F Sa 、F Sb Respectively represent the rolling and sliding fluid dynamic pressure friction forces in the long and short axis entrance areas of the contact surface between the cage pocket and the rolling element; ω x ,ω y is the rotation component of the x and y axes of the coordinate system;

[0227] Sliding friction power loss Q between the cage and the guide surface 7j :

[0228] Q 7j =M cx (ω l -ω c )

[0229] Among them, ω l is the speed of the guide ring; M cx Represents the hydrodynamic friction torque between the cage and the guide ring; ω c is the cage speed;

[0230] Assuming that all power loss is converted into heat generated by the bearing, the internal heat source of the bearing is concentrated in the contact area between the rolling element and the ring and the contact area between the rolling element and the cage. The heat generated in each area (considering the real-time operating status of the bearing) is:

[0231]

[0232] Among them, H inner is the heat of the contact area between the rolling element and the inner ring, H outer is the heat of the contact area between the rolling element and the outer ring, H pocket It is the heat of the contact area between the rolling element and the cage.

[0233] In a preferred embodiment of the present invention, step S4 divides the thermal nodes based on the bearing structure, specifically:

[0234] S401, divide the bearing into N according to the number of rolling elements b Each area contains a rolling element, inner and outer ring segments and a cage segment;

[0235] S402, determine the thermal node conditions of each area in step S401, and divide it into 7 nodes in total (depending on the bearing structure and research problems, nodes can be increased or decreased, not limited to 7 nodes), node 1 is the inner ring and shaft matching surface, node 2 is the rolling element and inner ring contact area, node 3 is the rolling element center of mass, node 4 is the rolling element and outer ring contact area, node 5 is the outer ring and bearing assembly matching surface, nodes 6 and 7 are the front and rear collision surfaces of the rolling element and the cage pocket; the bearing area has a total of 7N b Hot nodes;

[0236] S403, determine the thermal nodes of the non-bearing area. There are four thermal nodes in the non-bearing area: node 8 is the center of the shaft that cooperates with the bearing, node 9 is the outer surface of the bearing seat that cooperates with the bearing, node O is the lubricating oil gas, and node A is the air node.

[0237] In a preferred embodiment of the present invention, step S5 calculates the thermal resistance (e.g., Figure 3 and Figure 4 The method shown) is:

[0238] According to the relationship between heat conduction and heat convection when the bearing is running, the corresponding thermal resistance is calculated. The thermal resistance calculation formula for heat conduction is: The thermal resistance calculation formula for heat convection is:

[0239] S501, calculates radial thermal resistance, including:

[0240] Thermal resistance R from the inner surface of the inner ring to the contact area 12 :

[0241]

[0242] Among them, d i is the inner raceway diameter, d is the bearing inner diameter, k i is the thermal conductivity of the inner ring, B is the width of the inner ring; N b is the number of rolling elements;

[0243] Thermal resistance R from the contact area between the inner ring and the rolling element to the center of the rolling element 23 :

[0244]

[0245] Among them, k b is the thermal conductivity of the rolling element, α b is the thermal diffusivity; b i is the semi-minor axis of the inner contact ellipse, v i is the speed of the rolling element relative to the inner raceway, a i is the semi-major axis of the inner contact ellipse;

[0246] Thermal resistance R from the contact area between the outer ring and the rolling element to the center of the rolling element 34 :

[0247]

[0248] Among them, b e is the minor semi-axis of the external contact ellipse, v e is the speed of the rolling element relative to the outer raceway, a e is the semi-major axis of the outer contact ellipse;

[0249] Thermal resistance R from the outer surface of the outer ring to the contact area 45 :

[0250]

[0251] Where D is the outer diameter of the bearing, D e is the outer channel diameter, k e is the thermal conductivity of the outer ring, C is the width of the outer ring;

[0252] Thermal resistance R from the inner surface of the inner ring to the center of the axis 18 :

[0253]

[0254] Among them, k s is the thermal conductivity of the shaft;

[0255] Thermal resistance R from the outer surface of the outer ring to the surface of the bearing seat 59 :

[0256]

[0257] Among them, D h is the bearing seat surface diameter, k h is the thermal conductivity of the bearing seat;

[0258] S502, calculate the axial thermal resistance, including:

[0259] Thermal resistance R from shaft center to shaft end ′ 8A :

[0260]

[0261] Among them, L s is the distance from the shaft center to the shaft end;

[0262] Thermal resistance R from the bearing seat to the end face ′ 9Aa :

[0263]

[0264] Among them, L h The distance from the fitting point between the bearing seat and the bearing to the end face;

[0265] 503, calculation of circumferential thermal resistance, including:

[0266] Thermal resistance R between adjacent inner ring segments 22 :

[0267]

[0268] Thermal resistance R between adjacent outer ring segments 44 :

[0269]

[0270] Thermal resistance R from the center of the rolling element to the collision surface with the front and rear cage pockets 36 、R 37 :

[0271]

[0272] Among them, D c is the outer diameter of the cage, d c is the inner diameter of the cage;

[0273] Thermal resistance R between the front and rear pockets of adjacent cage segments 67 :

[0274]

[0275] Among them, k c is the thermal conductivity of the cage;

[0276] 504, Calculate the heat transfer resistance between bearings and lubricating oil and gas, including:

[0277] Thermal resistance R between rolling element and lubricating oil and gas 6O , R 7O :

[0278]

[0279] Among them, the rolling element heat transfer coefficient

[0280] Rolling element Reynolds number Pelectric number of lubricating oil and gas

[0281] k eff is the thermal conductivity of the oil-gas mixture, ρ eff is the density of the oil-gas mixture, μ effis the dynamic viscosity of the oil-gas mixture; D w is the rolling element diameter; d m is the bearing pitch diameter; ω m is the rolling element revolution speed;

[0282] Heat transfer resistance R between the inner ring and lubricating oil and gas 2O :

[0283]

[0284] Among them, the heat transfer coefficient of the inner ring section is

[0285] Nusselt number Reynolds number

[0286] Heat transfer resistance R between outer ring segment and lubricating oil and gas 4O :

[0287]

[0288] Among them, the heat transfer coefficient of the outer ring section is

[0289] Nusselt number Reynolds number d i is the inner raceway diameter, d e is the outer raceway diameter;

[0290] 505, calculate the heat transfer resistance between the shaft and bearing seat and the air, including:

[0291] Forced convection thermal resistance R″ between the shaft end and the air 8A :

[0292]

[0293] Among them, the heat transfer coefficient of the shaft end is

[0294] Nusselt number

[0295] Reynolds number Prair is the air Pelect number; k air is the thermal conductivity of air, μ air is the air dynamic viscosity;

[0296] Natural convection thermal resistance R between the outer surface of the bearing seat and the air 9Ar :

[0297]

[0298] Among them, h h is the natural flow coefficient between the bearing seat and the air, L h is the bearing seat length;

[0299] Natural convection thermal resistance R″ between the bearing seat end face and air 9Aa :

[0300]

[0301] 506, according to the series-parallel relationship (such as Figure 5 and Figure 6 As shown), calculate the equivalent thermal resistance between the air node and the non-bearing area:

[0302] R 8A =R ′ 8A +R″ 8A

[0303] R 9Aa =R ′ 9Aa +R″ 9Aa

[0304]

[0305] Among them, R 8A is the thermal resistance between the shaft and the air node, R 9Aa is the axial thermal resistance between the bearing seat and the air node, R 9A is the comprehensive thermal resistance between the bearing seat and the air node.

[0306] In a preferred embodiment of the present invention, step S6 constructs a full-node thermal network model of the bearing according to the real-time internal heat sources, thermal nodes, and thermal resistance of the bearing as follows:

[0307] According to the law of conservation of heat, the heat flow balance equation of each node is established to form a complete thermal network model. Assuming that the air node A and the lubricating oil gas node O are constant temperature nodes, the heat flow balance equation of the bearing area is established. The heat flow balance equation of the j-th bearing area contains:

[0308] Node 1:

[0309]

[0310] Node 2:

[0311]

[0312] Node 3:

[0313]

[0314] Node 4:

[0315]

[0316] Node 5:

[0317]

[0318] Node 6:

[0319]

[0320] Node 7:

[0321]

[0322] The bearing area has a total of 7N b Balanced equations, j = 1 ~ N b , N b is the number of rolling elements; Where T is temperature, superscript j is the jth rolling element, and subscript numbers are nodes; H pocket is the heat of the contact area between the rolling element and the cage;

[0323] Establish the heat flow balance equation in the non-bearing area. Node 8 has a heat transfer relationship with air node A and N b The heat conduction occurs at node 1 on the outer surface of the bearing end, and the heat flow balance equation is:

[0324]

[0325] Where T8 represents the temperature of node 8, T A represents the temperature of node A;

[0326] Node 9 has a heat transfer relationship with air node A and also with N b The heat conduction occurs at the node 5 on the outer surface of the bearing end, and the heat flow balance equation is:

[0327]

[0328] There are two equilibrium equations in the non-bearing area, where T9 represents the temperature of node 9.

[0329] In a preferred embodiment of the present invention, step S7 calculates the temperature of each thermal node divided in step S4 based on the bearing full-node thermal network model to obtain the entire bearing temperature distribution. The specific steps are as follows:

[0330] Rewrite all the heat flow balance equations in step S6 into the form of a non-homogeneous linear equation system:

[0331] A·T=H,

[0332] The unknown vector is represented as:

[0333]

[0334] Total M = 7N b +2 elements, N b is the number of rolling elements;

[0335] The coefficient matrix AA is:

[0336]

[0337] in, If there is no thermal effect between two thermal nodes, the thermal resistance is +∞; a pq is the matrix element, p, q and k are the element position numbers, R p，k , R p，q is the corresponding thermal resistance, is the deformation of the rewritten matrix form; M is the total number of unknown vector elements;

[0338] The elements of the constant term vector H are zero when there is no heat source and are the calculated heat generation when there is a heat source;

[0339] Solve the equations to get the temperature value of each node and calculate the temperature distribution (which changes with the bearing load distribution, such as Figure 7 shown).

[0340] The present invention also provides a bearing temperature distribution calculation system based on a full-node thermal network model, including a data acquisition module and a processing module. The data acquisition module is used to obtain the material parameters, dimensional parameters, working conditions and lubrication parameters of the bearing and transmit them to the processing module.

[0341] The processing module executes the method of the present invention to calculate the bearing temperature distribution.

[0342] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0343] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A method for calculating bearing temperature distribution based on a full-node thermal network model, characterized in that: The steps include: S1, obtaining the material parameters, size parameters, working conditions and lubrication parameters of the bearing; S2, calculates real-time motion parameters and mechanical parameters based on the bearing dynamics model; S3, calculating the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2; S4, divides multiple thermal nodes based on the bearing structure; S5, calculating the thermal resistance between each thermal node divided in step S4 based on the heat conduction and convection effects between the various components of the bearing; S6, constructs a full-node thermal network model of the bearing based on the real-time internal heat sources, thermal nodes, and thermal resistance of the bearing; S7, based on the bearing full-node thermal network model, calculate the temperature of each thermal node divided in step S4 to obtain the entire bearing temperature distribution.

2. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 1, characterized in that: In step S2, the method for calculating the real-time motion parameters and mechanical parameters based on the bearing dynamics model is: The bearing dynamics model uses a complete dynamics model to calculate real-time motion parameters, including: Rolling element rotation speed ω b ={ω x ,ω y ,ω z } T , where ω x ,ω y ,ω z are the rotation components of the x, y, and z axes of the coordinate system respectively; Rolling element revolution speed ω m 、Cage speedω c 、Inside and outside sliding speed v={v i ,v e } T ; Internal and external contact angles α = {α i ,α e } T , where α i ,α e Indicates internal contact angle and external contact angle, subscript i stands for internal and e stands for external; Computational mechanical parameters, including: Drag friction force F in the direction of the major axis of the inner and outer contact ellipses Ta ={F Tai ,F Tae } T , where F Tai Indicates the drag friction force in the direction of the major axis of the inner contact ellipse, F Tae is the drag friction force in the direction of the major axis of the external contact ellipse; Drag friction force F in the minor axis direction Tb ={F Tbi ,F Tbe } T , where F Tbi is the drag friction force in the direction of the minor axis of the inner contact ellipse, F Tbe is the drag friction force in the direction of the minor axis of the external contact ellipse; Internal and external Hertz contact force N = {N i ,N e } T , where N i ,N e They are internal contact force and external contact force respectively; Internal and external spin friction torque M S ={M si ,M se } T , where M si ,M se They are the inner spin friction torque and the outer spin friction torque respectively; The resistance F of the rolling element to the movement of the oil and gas lubricant D ; Rolling and sliding fluid dynamic pressure friction force F between the long and short axis entrance areas of the cage pocket and the rolling element contact surface Ra 、F Rb 、F Sa 、F Sb ; Fluid dynamic friction torque M between the cage and the guide ring cx .

3. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 1, characterized in that: Step S3 calculates the real-time internal heat source of the bearing based on the real-time motion and mechanical parameters obtained in step S2. The specific steps are as follows: Calculates local power losses in bearings, including: Rolling elastic hysteresis power loss Q 1j : Q 1j =0.25a h d m (1-γ0 2 )C j oh bj in, Among them, α h is the elastic hysteresis coefficient, d m is the bearing pitch diameter, j is the jth rolling element, and there are N b rolling elements; the subscripts i and e represent the inner ring and outer ring respectively, w is the rolling element diameter, α0 is the initial contact angle, K(e) is the first kind of elliptic integral, L(e) is the second kind of elliptic integral, a is the major semi-axis of the contact ellipse, b is the minor semi-axis of the contact ellipse, ∑ρ is the sum of the principal curvatures of the contact point between the rolling element and the ring, E′ is the equivalent elastic modulus of the two contacting objects; γ0 is a dimensionless parameter, Γ j is the intermediate parameter, ω bj is the rotation speed of the jth rolling element, N is the internal and external Hertz contact force; Differential sliding friction power loss Q 2j : Q 2j =F Tb v Among them, F Tb is the drag friction force in the direction of the minor axis, and v is the internal and external sliding speed of the rolling element; Spin-sliding friction power loss Q 3j : Q 3j =M s ω s Among them, M s is the internal and external spin friction torque, ω s is the spin speed: oh s =(ω-ω m )sina+ω b sin(a-b) Among them, ω is the speed of the inner and outer rings, β is the attitude angle; α is the inner and outer contact angle, ω m is the rolling element revolution speed, ω b is the rolling element rotation speed; Gyroscope friction power loss Q 4j : Among them, F Ta is the drag friction force in the direction of the minor axis; ω z is the rotation component of the coordinate system z-axis; Steel ball lubrication drag friction power loss Q 5j : Among them, F D It is the resistance of oil and gas lubricant to the movement of rolling elements; Friction power loss Q between cage pocket and steel ball 6j : Among them, F Ra 、F Rb 、F Sa 、F Sb Respectively represent the rolling and sliding fluid dynamic pressure friction forces in the long and short axis entrance areas of the contact surface between the cage pocket and the rolling element; ω x ,ω y is the rotation component of the x and y axes of the coordinate system; Sliding friction power loss Q between the cage and the guide surface 7j : Q 7j =M cx (oh l -oh c ) Among them, ω l is the speed of the guide ring; M cx Represents the hydrodynamic friction torque between the cage and the guide ring; ω c is the cage speed; Assuming that all power loss is converted into heat generated by the bearing, the internal heat source of the bearing is concentrated in the contact area between the rolling element and the ring and the contact area between the rolling element and the cage. The heat generated in each area is: Among them, H inner is the heat of the contact area between the rolling element and the inner ring, H outer is the heat of the contact area between the rolling element and the outer ring, H pocket It is the heat of the contact area between the rolling element and the cage.

4. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 1, characterized in that: Step S4 divides the thermal nodes based on the bearing structure, specifically: S401, divide the bearing into N according to the number of rolling elements b Each area contains a rolling element, inner and outer ring segments and a cage segment; S402, determine the thermal node conditions of each area in step S401, and divide it into 7 nodes, node 1 is the inner ring and shaft matching surface, node 2 is the rolling element and inner ring contact area, node 3 is the rolling element center of mass, node 4 is the rolling element and outer ring contact area, node 5 is the outer ring and bearing assembly matching surface, nodes 6 and 7 are the front and rear collision surfaces between the rolling element and the cage pocket; the bearing area has a total of 7N b Hot nodes; S403, determine the thermal nodes of the non-bearing area. There are four thermal nodes in the non-bearing area: node 8 is the center of the shaft that cooperates with the bearing, node 9 is the outer surface of the bearing seat that cooperates with the bearing, node O is the lubricating oil gas, and node A is the air node.

5. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 4, characterized in that: In step S5, the thermal resistance between the thermal nodes divided in step S4 is calculated based on the heat conduction and convection effects between the bearing components as follows: S501, calculates radial thermal resistance, including: Thermal resistance R from the inner surface of the inner ring to the contact area 12 : Among them, d i is the inner raceway diameter, d is the bearing inner diameter, k i is the thermal conductivity of the inner ring, B is the width of the inner ring; N b is the number of rolling elements; Thermal resistance R from the contact area between the inner ring and the rolling element to the center of the rolling element 23 : Among them, k b is the thermal conductivity of the rolling element, α b is the thermal diffusivity; b i is the semi-minor axis of the inner contact ellipse, v i is the speed of the rolling element relative to the inner raceway, a i is the semi-major axis of the inner contact ellipse; Thermal resistance R from the contact area between the outer ring and the rolling element to the center of the rolling element 34 : Among them, b e is the minor semi-axis of the external contact ellipse, v e is the speed of the rolling element relative to the outer raceway, a e is the semi-major axis of the outer contact ellipse; Thermal resistance R from the outer surface of the outer ring to the contact area 45 : Where D is the outer diameter of the bearing, D e is the outer channel diameter, k e is the thermal conductivity of the outer ring, C is the width of the outer ring; the thermal resistance R from the inner surface of the inner ring to the center of the axis 18 : Among them, k s is the thermal conductivity of the shaft; Thermal resistance R from the outer surface of the outer ring to the surface of the bearing seat 59 : Among them, D h is the bearing seat surface diameter, k h is the thermal conductivity of the bearing seat; S502, calculate the axial thermal resistance, including: Thermal resistance R' from shaft center to shaft end 8A : Among them, L s is the distance from the shaft center to the shaft end; Thermal resistance R' from the bearing seat to the end face 9Aa : Among them, L h The distance from the fitting point between the bearing seat and the bearing to the end face; 503, calculation of circumferential thermal resistance, including: Thermal resistance R between adjacent inner ring segments 22 : Thermal resistance R between adjacent outer ring segments 44 : Thermal resistance R from the center of the rolling element to the collision surface with the front and rear cage pockets 36 、R 37 : Among them, D c is the outer diameter of the cage, d c is the inner diameter of the cage; Thermal resistance R between the front and rear pockets of adjacent cage segments 67 : Among them, k c is the thermal conductivity of the cage; 504, Calculate the heat transfer resistance between bearings and lubricating oil and gas, including: Thermal resistance R between rolling element and lubricating oil and gas 6O , R 7O : Among them, the rolling element heat transfer coefficient Rolling element Reynolds number Pelectric number of lubricating oil and gas k eff is the thermal conductivity of the oil-gas mixture, ρ eff is the density of the oil-gas mixture, μ eff is the dynamic viscosity of the oil-gas mixture; D w is the rolling element diameter; d m is the bearing pitch diameter; ω m is the rolling element revolution speed; Heat transfer resistance R between the inner ring and lubricating oil and gas 2O : Among them, the heat transfer coefficient of the inner ring section is Nusselt number Reynolds number Heat transfer resistance R between outer ring segment and lubricating oil and gas 4O : Among them, the heat transfer coefficient of the outer ring section is Nusselt number Reynolds number d i is the inner raceway diameter, d e is the outer raceway diameter; 505, calculate the heat transfer resistance between the shaft and bearing seat and the air, including: Forced convection thermal resistance R″ between the shaft end and the air 8A : Among them, the heat transfer coefficient of the shaft end is Nusselt number Reynolds number Prair is the air Pelect number; k air is the thermal conductivity of air, μ air is the air dynamic viscosity; Natural convection thermal resistance R between the outer surface of the bearing seat and the air 9Ar : Among them, h h is the natural flow coefficient between the bearing seat and the air, L h is the bearing seat length; Natural convection thermal resistance R″ between the bearing seat end face and air 9Aa :

506. Calculate the equivalent thermal resistance between the air node and the non-bearing area based on the series-parallel relationship: R 8A =R′ 8A +R″ 8A R 9Aa =R′ 9Aa +R″ 9Aa Among them, R 8A is the thermal resistance between the shaft and the air node, R 9Aa is the axial thermal resistance between the bearing seat and the air node, R 9A is the comprehensive thermal resistance between the bearing seat and the air node.

6. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 5, characterized in that: Step S6: Based on the real-time internal heat sources, thermal nodes, and thermal resistance of the bearing, a method for constructing a full-node thermal network model of the bearing is as follows: Assuming that the air node A and the lubricating oil node O are constant temperature nodes, the heat flow balance equation of the bearing area is established. The heat flow balance equation of the j-th bearing area contains: Node 1: Node 2: Node 3: Node 4: Node 5: Node 6: Node 7: The bearing area has a total of 7N b Balanced equations, j = 1 ~ N b , N b is the number of rolling elements; Where T is temperature, superscript j is the jth rolling element, and subscript numbers are nodes; H pocket is the heat of the contact area between the rolling element and the cage; Establish the heat flow balance equation in the non-bearing area. Node 8 has a heat transfer relationship with air node A and N b The heat conduction occurs at node 1 on the outer surface of the bearing end, and the heat flow balance equation is: Where T8 represents the temperature of node 8, T A represents the temperature of node A; Node 9 has a heat transfer relationship with air node A and also with N b The heat conduction occurs at the node 5 on the outer surface of the bearing end, and the heat flow balance equation is: There are two equilibrium equations in the non-bearing area, where T9 represents the temperature of node 9.

7. The method for calculating bearing temperature distribution based on a full-node thermal network model according to claim 6, characterized in that: Step S7 calculates the temperature of each thermal node divided in step S4 based on the bearing full-node thermal network model to obtain the entire bearing temperature distribution. The specific steps are as follows: Rewrite all the heat flow balance equations in step S6 into the form of a non-homogeneous linear equation system: A·T=H, The unknown vector is represented as: Total M = 7N b +2 elements, N b is the number of rolling elements; The coefficient matrix AA is: in, If there is no thermal effect between two thermal nodes, the thermal resistance is +∞; a pq is the matrix element, p, q and k are the element position numbers, R p，k , R p，q is the corresponding thermal resistance, is the deformation of the rewritten matrix form; M is the total number of unknown vector elements; The elements of the constant term vector H are zero when there is no heat source and are the calculated heat generation when there is a heat source; Solve the equations, get the temperature value of each node, and find the temperature distribution.

8. A bearing temperature distribution calculation system based on a full-node thermal network model, characterized in that: It includes a data acquisition module and a processing module. The data acquisition module is used to obtain the material parameters, size parameters, working conditions and lubrication parameters of the bearing and transmit them to the processing module; The processing module executes the method according to any one of claims 1 to 7 to calculate the bearing temperature distribution.

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