| Continuous extrusion, as a new type of technology, is gradually replacing the traditional rolling technology. It is the main production mode of the nonferrous metal pipe, rod, wire and composite material. Continuous extrusion machine is one kind of special equipment for continuous extrusion production. The main shaft system, connected with other parts of the core shaft series spindle system is core component of continuous extrusion machine. But in the actual production in recent years, there are some damage problems, such as extrusion wheel surface damage, damage to the sleeve main shaft fracture, which make the lifetime of the main shaft too low.In order to solve the problem of the main shaft fracture and prolong the lifetime of the main shaft.This paper mainly carries out the following research work:(1) Mechanical analysis of the main shaft system is done, the calculation formula of each mechanical load of the main shaft system is deduced, and the calculated operating conditions are calculated. Material property data of main shaft system at different temperatures is found, which is prepared for the accurate finite element calculation.(2) By software ANSYS, FEM of the main shaft system is made and analyzed. Compared the FEA result of main shaft system with the FEA result of single shaft, combined with the main shaft actual damage,it is shown that the main shaft with hole is in stress concentration, this location is prone to damage by the long-term hydraulic nuts pretightening.(3) Through analysis, the hole direction of the main shaft is changed to increase the core strength of the shaft hole. By covering aluminium to the extrusion wheel and a shaft sleeve contact surface, the friction is increased. To guarantee under the premise of the original spindle system safety coefficient, hydraulic nuts pretightening stress decreases to 150MPa, and main shaft stress significantly is reduce.The feasibility of the optimized scheme is verified by experiments. |
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