Theoretical and Experimental Study of Oil Churning Resistance Torque of High-speed Gear Pair

doi:10.3901/JME.2021.01.049

Abstract

Abstract: Efficiency is one of the important research contents of the transmission system of new energy vehicles. An accurate drag torque model of the gear pair is crucial to improve the efficiency level of the transmission system. A model for calculating the high-speed oil churning resistance torque of the spur gear pair is proposed, without considering the influence of the windage. According to the contact condition between the high-speed gear and the lubricating oil during the operation, the gear resistance torque is divided into three parts: the frictional resistance torque on the end face of the gear, the frictional resistance torque on the peripheral surface, and the squeeze resistance torque on the meshing area. Using the fluid dynamic theory and tribological principles to derive the oil resistance torque of a single gear, the fluid continuity equation, momentum conservation, and Bernoulli's principle are used to derive the squeeze resistance torque of the gear meshing area to squeeze the lubricant. Theoretical calculation model of oil resistance torque of the whole gear pair was established. The experimental bench was built and the feasibility of the calculation model is verified by experiments with various operating parameters. The theoretical calculation results are in good agreement with the experimental results. On this basis, the influence of each parameter on the churning torque is completed. The results show that the rotation speed, tooth width, and oil immersion depth all have an influence on the oil churning resistance torque, of which the squeeze resistance torque of the gear pair meshing area has the largest proportion; the speed will produce a large amount of each component of the oil resistance torque. The tooth width does not affect the frictional resistance moment of the end face, but has a great influence on the frictional resistance moment of the squeeze and the peripheral surface; the influence of the depth of oil immersion on the resistance torque of the squeeze and the end surface frictional is more significant.

Key words: oil churning torque, end surface friction, peripheral surface friction, squeeze resistance, parameters analysis

CLC Number:

TH117

GUO Dong, CHEN Fangchao, LIU Jiao, SHI Xiaohui, LUO Dongyuan. Theoretical and Experimental Study of Oil Churning Resistance Torque of High-speed Gear Pair[J]. Journal of Mechanical Engineering, 2021, 57(1): 49-60.

References

[1] HEINGARTNER P,MBA D. Determining power losses in the helical gear mesh[J]. Gear Technology,2005, 9(10):32-37.
[2] DIAB Y,VILLE F,VELEX P. Investigations on power losses in high-speed gears[J]. Engineering Tribology,2006,220:191-198.
[3] HU Xiaozhou,JIANG Yiyao. Churning power losses of a gearbox with spiral bevel geared transmission[J]. Tribology International,2019,129:398-406.
[4] SEABRA J,MICHAELIS K,BERND R,et al. Influence factors on gearbox power loss[J]. Industrial Lubrication and Tribology,2011,63(1):46-55.
[5] 王连生,郝志勇,郑康. 变速箱阻滞力矩对齿轮系多体动力学及敲击噪声的影响[J]. 中南大学学报,2015(12):4453-4459. WANG Liansheng,HAO Zhiyong,ZHENG Kang. Influence of transmission blocking moment on multi-body dynamics and percussion noise of gear train[J]. Journal of Central South University,2015(12):4453-4459.
[6] BONESS R J. Churning losses of discs and gears running partially submerged in oil[C]//Proc. ASME Int. Power Trans. Gearing Conference,Chicago,1989:355-359.
[7] LUKE P,OLVER A V. A study of churning losses in dip-lubricated spur gears[J]. Journal of Aerospace Engineering,1991,213(5):337-346.
[8] CHANGENET C,VELEX P. A model for the prediction of churning losses in geared transmissions-preliminary results[J]. Transactions of the ASME,2007,1(129):128-133.
[9] CHANGENET C,OVIEDO M,VELEX P. Power loss predictions in gear transmissions using thermal networks-applications to a six-speed manual gearbox[J]. Transactions of the ASME,2006,5(128):618-625.
[10] International Organization for Standardization. ISO/TR-14179-1[S]. Switzerland,2001.
[11] SEETHARAMAN S,KAHRAMAN A. An investigation of load-independent power losses of gear systems[D]. Ohio State University,2009.
[12] DIAB Y,VILLE F. Experimental and numerical investigations on the air-pumping phenomenon in high speed spur and helical gears[J]. Mechanical Engineering Science,2005,219:785-800.
[13] SAEGUSA D,KWAI S. CFD analysis of lubricant fluid flow in automotive transmission[R]. SAE,2014.
[14] LIU H,JURKSCHAT T,LOHNER T,et al. Determination of oil distribution and churning power loss of gearboxes by finite volume CFD method[J]. Tribology International,2017,109:346-354.
[15] CONCLI F,GORLA C,DELLA TORRE A,et al. Churning power losses of ordinary gears:A new approach based on the internal fluid dynamics simulations[J]. Lubrication Science,2015,27(5):313-326.
[16] CONCLI F,GORLA C. Numerical modeling of the power losses in geared transmissions:Windage,churning and cavitation simulations with a new integrated approach that drastically reduces the computational effort[J]. Tribology International,2016,103:58-68.
[17] CARLO C,FRANCO C,KARSTEN S,et al. Hydraulic losses of a gearbox:CFD analysis and experiments[J]. Tribology International,2013,66:337-344.
[18] GUO Dong,CHEN Fangchao. Numerical modeling of churning power loss of gear system based on moving particle method[J]. Tribology Transactions,2020,63(1):182-193.
[19] TEREKHOV A. Hydraulic losses in gearboxes with oil immersion[J]. Vestnik Mashinostroeniya,1975,55(5):13-17.
[20] LAUSTER E,BOOS M. Zum Wärmehaushalt mechanischer Schaltgetriebe für Nutzfahrzeuge[J]. VDI-Ber,1983,488:45-55. LAUSTER E,BOOS M. For the heat balance of mechanical gearboxes for commercial vehicles[J]. VDI-Ber,1983,488:45-55.
[21] CAMERON A. 润滑理论基础[M]. 北京:机械工业出版社,1980. CAMERON A. Theoretical basis of lubrication[M]. Beijing:China Machine Press,1980.
[22] 佟庆理. 两相流动理论基础[M]. 北京:冶金工业出版社,1982. TONG Qingli. Theoretical basis of two-phase flow[M]. Beijing:Metallurgical Industry Press,1982.
[23] 吴望一. 流体力学[M]. 北京:北京大学出版社,1982. WU Wangyi. Fluid mechanics[M]. Beijing:Peking University Press,1982.
[24] STREETER L V,WYLIE E B. Fluid mechanics[M]. 8th ed. New York:McGraw-Hill,1985.
[25] 王伟,贠超. 机器人机构精度综合的正交试验法[J]. 机械工程学报,2009,45(11):24-30. WANG Wei,YUN Chao. Orthogonal experimental design to synthesize the accuracy of robotic mechanism[J]. Journal of Mechanical Engineering, 2009,45(11):24-30.
[26] 李波. 空间润滑谐波减速器传动性能正交试验分析[J]. 机械工程学报,2012,48(3):82-87. LI Bo. Orthogonal experimental analysis on transmission performance of space lubricated harmonic drive[J]. Journal of Mechanical Engineering,2012,48(3):82-87.