| The shaft-sleeve-base sandwich structure widely exists in mechanical products and is a key component in this structure.The sleeve in the shaft-base interference fit is easily damaged,and needs to be frequently disassembled,replaced and repaired.the existing disassembly methods have great damage to parts.A new disassembly method of interference fit shaft sleeve under cold excitation is proposed in this thesis.The influencing factors and changing rules of disassembly force are explored by theory,simulation and experiment,and the disassembly performance optimization is studied.The main contents of this thesis is as follows:(1)Studying the heat transfer mechanism of interference fit sleeve-base under cold excitation conditions.The transient temperature field,average contact stress and disassembly force are deduced by using the theoretical knowledge of heat transfer,elastic mechanics and tribology,and are verified by the finite element method.(2)The effects of interference,cold excitation time,thickness and match length on the disassembly force during cold excitation are studied by means of single factor analysis and orthogonal analysis;The regression analysis is carried out on the disassembly force,and the regression equation between the disassembly forces on different factors is established,and the verification prediction is carried out.(3)The disassembly experiment on liquid nitrogen cold excitation is carried out,and the maximum disassembly force and instant disassembly force are studied.The correctness of the finite element simulation and the orthogonal simulation are verified.The surface morphology of the test before and after shows that cold excitation disassembly method can help reduce the surface damage and facilitate disassembly and remanufacturing.(4)The disassembly force of the interference fit shaft was optimized from three aspects: solid surface contact thermal resistance,insulation coating and slotted shaft.The influence of relevant model parameters on cold excitation disassembly was investigated.Providing theoretical support for interference fit parts optimization design. |
