Research On Remanufacturing Processes Of Used Car CVT Transmissions

Nowadays the demand for automobiles is increasing,however,simultaneously the developing automobile industry has caused tremendous resource and energy consumption as well as serious environmental pollution.One of the best solutions for this contradiction is remanufacturing.As the technical bottlenecks of CVT are overcome,the rate of passenger vehicle equipped CVT is increasing.In order to solve the following problem of used CVT,researches on technology for remanufacturing in the field are necessarily and urgently needed.In this study,the assessment of remanufacturability of a CVT equipped with transverse engine mounting and FF vehicle and researches on technology of remanufacturing were carried out.The study includes several following aspects:(1)A set of remanufacturing assessment indexes are put forward and applied to remanufacturability assessment of CVT.The parts of active conical wheel assembly,passive conical wheel assembly and input shaft assembly of CVT are classified and the corresponding indexes were calculated.Compared with the differential mechanism of manual transmission,the result indicates that the first two have better remanufacturability.(2)The disassembly model bases on polychromatic sets theory was established.And by appling this model,the disassembly sequences of conical wheel assembly were obtained.(3)The remanufacturing process flow of used CVT,especially the clean and disassembly steps in that process,is formulated.In addition,the formulation of remanufacturing process of valve body and pressure plate of hydraulic torque converter was also completed.(4)In order to repair worn surface of conical wheel through laser cladding,the experiment that laser clad Ni60A+20%WC on 20 CrMnTi is exploredt.The metallurgical bonding is obtained between substrate and laser cladding coatings,which indicated a dense tissue--the hardness of laser cladding coatings with cracks is lower than 60 HRC.(5)The typical faults of CVT and corresponding reasons are listed and the performance requirements of remanufactured CVT are put forward.Simultaneously the test of remanufactured CVT is done by test rig,and the result data are in accordance with remanufactured produc standards.