Based on numerical results of temperature field and stress field, a theoretical model is built to investigate thermal flux and actual contact area of the clutch friction pair during slipping process, which is validated by continuous temperature measurements and static pressure tests. Several coefficients are introduced to express slipping process of clutch friction pair:dynamic slipping thermal deformation coefficient Kα, static uneven contact coefficient Kδ, and interface pressure perturbation coefficient K. Occurrence probability of high-pressure and high-temperature areas is greater by the smaller actual contact area which leads to a larger value of interface pressure coefficient K as well. Calculation and experiment results indicate that the actual contact area ratio ranges from 40% to 60% for copper-base friction pair with low and middle friction thermal flux, and 20% to 40% with high friction thermal flux. While the friction thermal flux reaches at or above the limit, the ratio of the actual contact area to the nominal contact area is only 10%-15%.
LI Heyan
,
WANG Yusen
,
XIONG Cenbo
,
CHEN Fei
,
LI Mingyang
,
YANG Shuo
. Effect of Radial Temperature Gradient on Interface Pressure of Clutch Friction Pair[J]. Journal of Mechanical Engineering, 2018
, 54(1)
: 136
-143
.
DOI: 10.3901/JME.2018.01.136
[1] YI Y B,DU S,BARBER J R,et al. Effect of geometry on thermoelastic instability in disk brakes and clutches[J]. Journal of Tribology,1999,121(4):661-666.
[2] LEE K,BARBER J R. An experimental investigation of frictionally-excited thermoelastic instability in automotive disk brakes under a drag brake application[J]. Journal of Tribology,1994,116(3):409-414.
[3] BARBER J R. Thermoelastic instabilities in the sliding of conforming solids[J]. Wear,1970,15(4):296-296.
[4] 马彪,赵家昕,陈漫,等. 摩擦材料特性对离合器热弹性不稳定性的影响[J]. 机械工程学报,2014,50(8):111-118. MA Biao,ZHAO Jiaxin,CHEN Man,et al. Effect of friction material properties on thermoelastic instability of clutches[J]. Journal of Mechanical Engineering,2014,50(8):111-118.
[5] ZAGRODZKI P,TRUNCONE S A. Generation of hot spots in a wet multidisk clutch during short-term engagement[J]. Wear,2003,254(5):474-491.
[6] MARKLUND P,LARSSON R. Wet clutch friction characteristics obtained from simplified pin on disc test[J]. Tribology International,2008,41(9):824-830.
[7] ZHAO J,MA B,LI H,et al. The effect of lubrication film thickness on thermoelastic instability under fluid lubricating condition[J]. Wear,2013,303(1-2):146-153.
[8] ВОЛКОВ Ю П,БОЙКОВ А В. 履带车辆的设计与计算[M]. 刘大来,译. 北京:北京理工大学出版社,1972. ВОЛКОВ Ю П,БОЙКОВ А В. Design and calculation of tracked vehicle[M]. Translated by LIU Dalai. Beijing:Beijing Institute of Technology Press,1972.
[9] 张金乐,马彪,张英锋,等. 湿式换档离合器热特性仿真[J]. 吉林大学学报:工学版,2011,41(2):321-326. ZHANG Jinle,MA Biao,ZHANG Yingfeng,et al. Simulation of thermal characteristic of wet shift clutch[J]. Journal of Jilin University:Engineering and Technology Edition,2011,41(2):321-326.
[10] 许晋. 湿式换档离合器热负荷特性与试验方法研究[D]. 北京:北京理工大学,2007. XU Jin. Study on thermal load characteristic and experiment method of wet shifting clutch[D]. Beijing:Beijing Institute of Technology,2007.
[11] XIONG C,MA B,LI H,et al. Experimental study and thermal analysis on the buckling of friction components in multi-disc clutch[J]. Journal of Thermal Stresses,2015:1325-1345.
[12] 夏长高,朱茂桃. 离合器基本参数和主要尺寸的优化设计[J]. 江苏理工大学学报,1996(5):29-34. XIA Changgao,ZHU Maotao. Optimum design of basic parameters and main sizes of clutch[J]. Journal of Jiangsu University of Science and Technology,1996(5):29-34.
[13] MARKLUND P,MAKI R,LARSSON R,et al. Thermal influence on torque transfer of wet clutches in limited slip differential applications[J]. Tribology International,2007,40(5):876-884.
[14] 王志明. 离合器摩擦副界面形貌表征及其对接触面积的影响研究[D]. 北京:北京理工大学,2013. WANG Zhiming. Study on token of clutch surface morphology and its influence on contact area[D]. Beijing:Beijing Institute of Technology,2013.
[15] 曲在纲,黄月初. 粉末冶金摩擦材料[M]. 北京:冶金工业出版社,2005. QU Zaigang,HUANG Yuechu. Power metallurgy frictional materials[M]. Beijing:Metallurgical Industry Press,2005.
