Research On Wear Scar Characteristics Of Discontinuous Contact Steel Wire With Wire Rope CVT

Metal belt continuously variable transmission(Metal Belt Continuously Variable Transmission referred to as MB-CVT)has attracted much attention because of its excellent performance in fuel economy,power performance and driving comfort.However,its core part,thrust steel belt,has been monopolized by foreign companies for a long time.In this context,our team proposed a new type of CVT-Wire Rope Continuously Variable Transmission WR-CVT)using wire rope ring instead of thrust belt.Based on the Xi’an science and technology project’ Development of Hybrid Passenger Vehicle Steel Ring Continuously Variable Transmission’(approval number:2019217714GXRC013CG014-GXYD13.7),6×19+IWS wire rope is taken as the research object.The wire rope is simulated under continuous and discontinuous contact conditions,and the wear experiment of wire rope under different contact conditions is carried out under constant(variable)transmission ratio and rotational speed.The wear characteristics of wire rope are analyzed,which provides theoretical basis for the wear mechanism and fatigue life of wire rope.This paper analyzes the basic structure and working principle of WR-CVT,deduces its transmission geometric relationship,and analyzes the force of pulley,wire rope and metal block;Based on the principle of differential geometry,the spatial curve equation of 6×19+IWS bending wire rope was deduced and the geometric model was established,The finite element models of continuous and discontinuous contact were established by ABAQUS software,and the stress and deformation of wire rope under different contact conditions were discussed;The friction and wear experiments of steel wire rope under different contact conditions at constant transmission ratio and rotational speed were carried out by using the self-made continuous-discontinuous contact steel rope ring damage joint test bench.The morphology and evolution of wear scar parameters on the surface of the steel wire rope were compared and analyzed;Aiming at the fatigue failure of steel wire rope after friction and wear under different transmission ratio and speed,the friction and wear tests of steel wire rope under different contact conditions were carried out under variable transmission ratio and speed,and the evolution law of wear scar morphology and wear scar parameters of steel wire rope were compared and analyzed;The results show that under the constant transmission ratio and rotational speed,the reduction order of the surface wear parameters of the side strand outer layer steel wire under different contact is as follows:the side strand outer layer steel wire contacted with the discontinuous groove and the steel wire between the adjacent side strands,the side strand outer layer steel wire contacted with the continuous groove and the steel wire between the adjacent side strands,that is,the contact of the steel wire rope with the discontinuous pulley aggravates the friction and wear of the steel wire and reduces the service life of the steel wire rope;At variable transmission ratio and speed,with the same pulley speed,with the increase of transmission ratio,the wear scar parameters of steel wire surface first decrease rapidly and then increase slowly.When the transmission ratio is 1,the wear scar size parameters of steel wire rope are the smallest.When the transmission ratio is the same,with the increase of pulley speed,the wear scar parameters of wire rope increase,and the speed is positively correlated with the wear degree of wire rope.In this paper,the wear scar characteristics of steel wire in the process of discontinuous contact between steel wire rope and metal block are studied,which lays a theoretical foundation for further exploring the wear mechanism of steel wire rope,fatigue life and improving the mechanical properties of steel wire rope.