CN-116008338-B - Method for evaluating heat dissipation capacity of wet friction plate oil groove

Abstract

The invention discloses a wet friction plate oil groove heat radiation capability evaluation method which comprises the steps of determining oil groove simulation schemes of m friction plates, respectively constructing friction plate oil groove flow field analysis models corresponding to the m oil groove simulation schemes in flow field analysis software, obtaining heat radiation power and oil film shearing moment of the inner surface of an oil groove on the surface of the friction plate when the heat radiation rotating speed and the cooling flow are changed, and calculating to obtain the heat radiation coefficient of the friction plate in the ith oil groove simulation scheme, comparing the calculated heat radiation coefficient of the oil groove in the m oil groove simulation schemes, wherein the oil groove simulation scheme with the optimal comprehensive heat radiation performance is the largest value of the heat radiation coefficient of the oil groove, and the method can meet the design requirement of the fine heat radiation design of the friction plate.

Inventors

• HAN MING
• ZHANG WANHAO
• ZHANG GUOHONG
• HU ZHENG
• DAI GUOWEN
• Jin Kongjie
• XU CHENGFA
• NING KEYAN
• ZHOU HUANHUI
• WANG ZHIYONG

Assignees

• 中国北方车辆研究所
• 杭州前进齿轮箱集团股份有限公司

Dates

Publication Date

20260508

Application Date

20221028

Claims (3)

1. 1. The method for evaluating the heat dissipation capacity of the wet friction plate oil groove is characterized by comprising the following specific steps of: step 1, determining oil groove simulation schemes of m friction plates, wherein the oil groove simulation scheme of each friction plate can calculate n typical heat dissipation rotating speeds and p typical cooling flow using working conditions; Step 2, respectively constructing friction plate oil groove flow field analysis models corresponding to m oil groove simulation schemes in flow field analysis software; step 3, obtaining the heat dissipation power and the oil film shearing moment of the inner surface of the oil groove on the surface of the friction plate when n types of typical heat dissipation rotating speeds and p types of typical cooling flows are adopted in m oil groove simulation schemes by changing the heat dissipation rotating speeds and the cooling flows; and according to the heat dissipation power and the oil film shearing moment, calculating to obtain the heat dissipation coefficient of the friction plate oil groove in the ith oil groove simulation scheme ,i=1,2,...,m; Under the condition of fixing a certain cooling flow, when only the heat dissipation rotating speed is changed, the heat dissipation coefficient of the friction plate oil groove in the ith oil groove simulation scheme is calculated The specific formula of (2) is as follows: Formula (1) Wherein, the Heat dissipation coefficient for the oil groove structure in the i-th oil groove simulation scheme, i=1, 2,..m; Rotational speed weight coefficient for the j-th typical heat radiation rotational speed, j=1, 2,..n, and ; The surface heat dissipation power is the surface heat dissipation power of the ith oil groove simulation scheme and the jth typical heat dissipation rotating speed; oil film shearing moment at the j-th typical heat dissipation rotating speed and the i-th oil groove simulation scheme; The j-th typical heat dissipation rotational speed; The heat dissipation power and the oil film shearing moment of the inner surface of the oil groove on the surface of the friction plate when the heat dissipation rotating speed and the cooling flow are changed are obtained according to m oil groove simulation schemes, n typical heat dissipation rotating speeds and p typical cooling flows; calculating according to a formula (2) to obtain the oil groove heat dissipation coefficient of the friction plate in the ith oil groove simulation scheme; Formula (2) Wherein, the Flow weighting coefficient for the x-th typical cooling flow, x=1, 2,..p, and ; The simulation scheme is the i-th oil groove simulation scheme, the j-th typical heat dissipation rotating speed and the x-th surface heat dissipation power at the typical cooling flow; The oil film shearing moment is the oil groove simulation scheme of the ith oil groove, the typical heat dissipation rotating speed of the jth oil groove and the typical cooling flow of the xth oil groove; The cooling speed is the j-th typical cooling speed and the x-th typical cooling flow; Step 4, comparing the oil groove heat dissipation coefficients calculated by the m oil groove simulation schemes, wherein the oil groove heat dissipation coefficient with the largest numerical value is the oil groove simulation scheme with the optimal comprehensive heat dissipation performance; step 5, according to the heat dissipation energy value Q and the corresponding heat dissipation time t required by the known friction plate, according to Evaluating whether the heat dissipation capacity of the oil groove in each oil groove simulation scheme meets the heat dissipation requirement; If it is The friction plate is considered to meet the heat dissipation requirement by adopting the ith oil groove simulation scheme, if The friction plate is considered to be in an i-th oil groove simulation scheme which does not meet the heat dissipation requirement.
2. 2. The method for evaluating the heat dissipation capacity of an oil groove of a wet friction plate as claimed in claim 1, wherein in the step 1, the specific process of determining the oil groove simulation scheme of m friction plates is as follows: Step 1-1, determining the use working conditions of a friction plate, wherein the use working conditions comprise n typical heat dissipation rotating speeds and p typical cooling flows, and simultaneously determining a rotating speed weight coefficient corresponding to each typical heat dissipation rotating speed and a flow weight coefficient corresponding to each typical cooling flow; And 1-2, preliminarily determining the oil groove simulation schemes of the m friction plates by adjusting the groove type, the groove section size parameters and the oil groove distribution size parameters of the friction plate oil grooves according to experience, and completing three-dimensional modeling according to the groove type, the groove section size parameters and the oil groove distribution size parameters of the friction plate oil grooves of each oil groove simulation scheme.
3. 3. The method for evaluating heat dissipation capacity of a wet friction plate oil groove as claimed in claim 1, wherein in step 2, after friction plate oil groove flow field analysis models corresponding to m oil groove simulation schemes are respectively constructed in flow field analysis software, a drainage basin boundary is set for each friction plate oil groove flow field analysis model, and the drainage basin boundary comprises heat dissipation rotation speed and cooling flow.

Description

Method for evaluating heat dissipation capacity of wet friction plate oil groove Technical Field The invention belongs to the technical field of structural design, and particularly relates to a method for evaluating heat dissipation capacity of an oil groove of a wet friction plate. Background In a vehicle transmission system speed change mechanism, a wet brake, and a wet clutch, friction plates are widely used for realizing functions such as gear shift, torque transmission, and braking. In the working process of the friction plate, a large amount of heat is generated by sliding friction with the dual plate, the surface temperature of the friction plate and the dual plate is greatly increased due to excessive heat, even the problems of ablation, adhesion, buckling deformation and the like of the friction plate and the dual plate occur, the performance of the friction plate is seriously influenced, and even the function is invalid. In order to reduce the temperature of the friction plate, the friction plate and the dual plate are generally cooled by a cooling liquid, and the cooling effect is related to the flow rate, quality, flow rate of the cooling liquid and the like. In order to further improve the cooling effect, an oil groove is usually formed in the surface of the friction plate, the heat exchange area of the cooling liquid is increased through the oil groove, and meanwhile, the oil groove can also obviously influence the flowing state of the cooling liquid, so that the heat dissipation effect of the friction plate is changed. Common oil grooves are formed by spiral grooves, radial grooves, waffle grooves, double-arc grooves, wedge grooves, circumferential grooves and the like, and various oil grooves can be combined to obtain different heat dissipation effects. How to quickly select the oil groove scheme with the best heat dissipation capability from a plurality of oil groove forms according to the application conditions of the friction plate is a problem which has long plagued friction plate designers and friction plate manufacturers. The current friction plate oil groove design method mainly comprises experience design, test comparison, simulation comparison and the like. The experimental design method is characterized in that an existing design scheme is adopted, a new oil groove scheme is formed by slightly changing the existing design scheme, as shown in a figure 1, friction plates in different oil groove forms are processed by a test comparison method, heat dissipation comparison under the same working condition is carried out on a test bench, the heat dissipation capacity of various oil grooves is evaluated according to the highest temperature of the tested friction plates or the heat resistance performance of the friction plates, as shown in a figure 2, flow field analysis models of the oil grooves in different forms are constructed by simulation analysis, and the heat dissipation capacity of the oil grooves is evaluated according to the convection heat exchange coefficient of the surface under the given working condition, as shown in a figure 3, which is obtained by the simulation analysis. However, the empirical design method of the oil groove is not accurate enough, even when the existing design is blindly used, the heat dissipation effect is far lower than expected, the experimental comparison method generally finishes a comparison test through a processing test piece to carry out screening and optimization, the early investment is large, the processing period and the test period are long, and the improvement of the oil groove design technology is restricted. The simulation analysis method is a newly developed oil groove heat dissipation calculation method in recent years, carries out heat dissipation analysis on different oil groove schemes based on the flow field simulation analysis method, compares the heat dissipation effect of the oil groove according to the convective heat transfer coefficient, remarkably reduces the design period and the economic investment of the oil groove, and has good popularization prospect in the oil groove design. However, the heat dissipation is affected by the oil groove of the friction plate, and the idle oil stirring loss is caused in the idle process of the friction plate, so that the larger the heat dissipation power of the surface of the oil groove is, the better the heat dissipation power cannot be pursued on one side, and the idle oil stirring loss is also compared. In addition, the oil groove is evaluated according to the use condition and the requirement, the design scheme of the oil groove can have different change trends under different rotating speeds and different flows, the heat dissipation capacity is good under the condition A, and the heat dissipation is poor under the condition B. Therefore, the method is free from the use condition, does not consider the oil stirring loss of the oil groove, simply compares schemes according to simulatio