In order to analyze temperature field and stress field of Co-based alloys laser cladding, the model of Co-based alloys laser cladding with preset-powder method has been made on low carbon steel substrate. The temperature field and stress field of laser cladding process was analyzed by SYSWELD software, and Experimental verification is done. The results showed that temperature field is appear to a trailing tail of comet, favorable metallurgy bonding with 12.3% dilution was obtained by scanning velocity was 4 mm/s. and instantaneous cooling rate of molten pool with 4 mm/s and 5 mm/s are increased to 1.47 times and 2.02 times of 3 mm/s. The transverse residual stress different nodes on the surface of coatings are always tensile stress, and it is almost steady, the maximum deformation is 0.34 mm at the edge of work-piece, these are consistent with experimental results. These results provide reference and guide to obtain high quality coatings.

Basing on the theory of the meshing principle and the differential geometry, deduced the contact wire function for the new sine gears. In explanation of the gear parameters influencing to the contact wire function, imitated the contact function using the regular changes values of the amplitude value H and the helix angle β with MATLAB. From the imitation derived the evolution of the contact wire influencing by the amplitude value H and the helix angle β. The contact wire moved following with the enlarge amplitude value H to the forward direction of the high tooth and the forward direction of the width tooth; The contact wire also moved following with the enlarge helix angle β to the negative direction of the high tooth and the negative direction of the width tooth. Thereby, in order to select the appropriate gear parameters provided basis.

Because of low level of informatization in automobile main gear reducer assembly line, it is proper to put forward Manufacturing Execution system to monitor, control and manager the production assembly line. First, functional requirements and coverage of MES system is investigated. Second, function of the MES for automobile main gear reducer assembly line is described. Third, the results of implementation on the line are discussed. It is proved that the efficiency of assembly line and the field management can be improved using MES system.