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At present, the traditional heavy-duty diesel engine main rotor and core shaft docking process solution has low precision, backwards supporting equipment, poor stability and other problems. In this paper, several solutions are proposed to address these problems, and two new designs are finally identified. Option A is to improve the accuracy of the main rotor-core shaft alignment by changing the placement of the rotor and core shaft, using telescopic hydraulic cylinders and adopting fixtures to fix them; Option B uses 3D laser scanning technology, high-precision truss manipulators and "trap" type structural fixtures to solve the problem of inaccurate alignment between the keyway in the rotor cavity and the core shaft key and the inaccurate alignment between the rotor and the core shaft key. We also used 3D modelling and animation to solve the problems of the rotor core and core shaft shaking when the platform moves. We also simulated the working process of the two solutions through 3D modelling and animation. After comparison and analysis, both solutions can effectively achieve the automatic alignment of the rotor core and the core shaft key, ensure the coaxially of the rotor and the core shaft, and reduce the offset.

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An new composite strengthening and prolongation technique was discussed on the key components of pellet traveling grate, which are prone to thermal vibration fatigue, contact fatigue and wear resistance under the alternating high/low temperature. CO 2 laser remelting was used to subject the key components of pellet traveling grate, improving the material's surface hardness, and the advanced surface treatment technique by utilizing intense laser shockwave was adopt. The impact of residual compressive stress generated by laser shock processing on fatigue life of surface cracks was discussed, and laser shock could effectively alleviate the residual stress at the surface and significantly improve the fatigue life and anti-stress corrosion performance. The result shows that composite laser treatment could effectively close up and repair cracks. 1.INTRODUCTIONSMetal structure's long service life and high durability as well as repair of its microcracked material have drawn more and more attentions in current international fields of mechanics, material, structure and dynamics, and have become fast developing studying issues. As the core equipment in pellet material production, chain grate is large-scale equipment with non-standard design, and the operation chain system, as its core part, is in long-term running under alternating temperature varying from normal one to 1050 . The complex thermal expansion and alternating thermal stress formed under the alternating temperature environment leads to the short service life of the heat-resisting component which, after a definite service cycle, will be inevitably microcracked. These micro-cracks will continue extending once formed, so it is necessary to repair them from the beginning when they are formed. The method often used in existing technologies is weld repair. This crack eliminating method has repairing effects only on metal surfaces, but may generate few traction forces to both walls of the crack, without improvement for interior stress changes after cracks are formed. Therefore, despite the repairing effect shortly after repair, the effective duration is short, and it is still possible that the crack will be aggravated or new cracks might reoccur afterwards. It is a reliable structure-reinforcing and life-extending approach to use composite patches to repair metal structures, which has the advantages of low cost and high benefit as well. However, high-temperature solidification treatment is required in its action process. Besides, the treatment costs time, and the technology is complicated, which are not favorable to on-site real-time operation. So by now, there have been few technologies in actual large-scale application for metal structure repair and re-production. It is of urgent need to develop new theories, technologies and techniques, and to enrich the technology of metal structure repair and re-production, so that more options are available for seeking the optimal repairing scheme.When reciprocating under the environment varying from normal temperature to high te...

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