Principle and characteristics of original hydraulic traction drive CVT

Abstract

A new CVT (continuously variable transmission) design which is a traction drive variator has been introduced. Analytical predictions and experimental results of the steady state which demonstrate higher efficiencies and power capacities of the new design are presented. The traction and power loss are then predicted by using models including evaluation of creep and spin in the contact patch. Analytical predictions of the transmission reach reasonable agreement with the experimental data, and the transmission efficiency of the system increases as the input torque increases while the input speed is certain. The research results can be further used in hydraulic traction drive CVT design and optimization.

Keywords

continuously variable transmission / spin / creep / efficiency / elasto-hydrodynamic

References

[1] CarterJ, PohlB, RutterB I, RaneyR, SadlerB. The turbo trac traction drive CVT [C]. 2004 International Continuously Variable and Hybrid Transmission Congress. San Francisco, 200438-44

[2] CarterJ, MillerD. The design and analysis of an alternative traction drive CVT [C]. 2003 SAE World Congress, 2003, Michigan, SAE

[3] WangS-h, XuX-y, LiuY-f, et al. . Design and dynamic simulation of hydraulic system of a new automatic transmission [J]. Journal of Central South University of Technology, 2009, 16(4): 697-701

[4] KimJ, ParkF C, ParkY, ShizuoM. Design and analysis of a pherical continuously variable transmission [J]. Journal of Mechanical Design, 2002, 124(3): 21-29

[5] AiX-lan. Development of zero-spin planetary traction drive transmission: Part 1. Design and principles of performance calculation [J]. Journal of Tribology, 2002, 124(4): 387-391

[6] SrivastavaN, HaqueI. Transient dynamics of the metal V-Belt CVT: Effects of pulley flexibility and friction characteristic [J]. Journal of Computational and Nonlinear Dynamics, 2007, 2(1): 86-97

[7] ZhenC H, LimW S, ChaS W. Performance optimization of CVT for two-wheeled vehicles [J]. International Journal of Automotive Technology, 2011, 12(3): 461-468

[8] LiZ, QinD-tong. Transmission characteristics of half-toroidal traction drive continuously variable transmission [J]. China Mechanical Engineering, 2005, 16(6): 490-494

[9] ImanishiT. Development of high Power-Density Double Cavity Half toroidal CVT [C]. The JSME International Conference on Motion and Power Transmissions, 2001, Fujuoka, Japan, JSME: 860-863

[10] Toroidal CVT: China, 200910164830 [P]. 2010-02-10.

[11] Toroidal CVT Drive systemChina, 98800604. 9 [P], 1997

[12] TevaarwerkJ L, JohnsonK L. The influence of fluid rheology on the performance of traction drives [J]. Journal of Lubrication Technology, 1979, 101(3): 1015-1022

[13] CretuS, GlovneaR P. Traction drive with reduced spin losses [J]. Journal of Tribology, 2003, 125(7): 125-507

[14] KumarP, KhonsariM M. Combined effects of shear thinning and viscous heating on EHL characteristics of rolling/sliding line contacts [J]. Journal of Tribology, 2008, 130(10): 1-13

[15] TevaarwerkJ L, JohnsonK L. The influence of fluid theology on the performance of traction drives [J]. Transactions of the ASME, 1979, 101(7): 2661-273

[16] GoodyerC E, FairlieR, BerzinsM, ScalesL E. Adaptive mesh methods for elastohydrodynamic lubrication [C]. ECCOMAS Computational Fluid Dynamics Conference. Swansea, 20111-17

[17] FortiA D F. The influence of spin and lifetime in design of traction drive continuously variable transmissions [C]. SAE Technical Paper, 2001

[18] TakeshiY, ToshikazuO, MasakiNakano. Improvement of loading cam performance in a toroidal CVT [J]. Society of Automotive Engineers of Japan, 2002, 23(4): 481-487

[19] StuartH L, DouglasA R. United States. Regression analysis of traction characteristics of two traction fluids [J]. NASA Technical Paper, 19832154-21