Research On Leaf Spring Damping And Its Dynamic Characteristics Of Large-Tonage Radiation Protection Excavator Cockpit

All the components of large-tonnage radiation protection excavator cockpit are rigidly connected and fixed by bolts or welding. Shocks or vibrations generated in the process of the excavator moving or working may lead to structural failure or damage and affect the reliability of components. Therefore the damping needs to be designed to ensure the life of evacuate cockpit and the assembly. The radiation protection cockpit makes the weight of excavator gain 5.4 tons, and that is far exceeded the silicone-oil damper can afford which is used in the ordinary excavator. The main topic is designing the damping device of large-tonnage radiation protection excavator cockpit, studying its dynamic characteristics, developing radiation protection excavator cockpit which has dynamic comfort and handling stability under the environment of nuclear leakage and decommissioning of nuclear facilities. The overall study are as follows:(1)Select elastic component for leaf spring damping, determine the geometric parameters of leaf spring and establish its solid and finite element model.(2)Carry out finite element static analysis of leaf spring under different friction coefficients and different loads, then come to a conclusion that friction coefficients and loads have little effect on the distribution of equivalent stress. With the increase of friction coefficient, the equivalent stress decreases,and the friction coefficient has a small impact on the static stiffness of leaf spring.(3)Carry out transient dynamic analysis of leaf spring. Friction leads to hysteresis of vibration response under sinusoidal loads. And the larger friction coefficient the larger damping factor,friction coefficient is proportional to damping factor. The load frequency has little effect on hysteresis characteristic and dynamic stiffness of leaf spring. On the contrary, the amplitude has a great effect on hysteresis characteristics and dynamic stiffness of leaf spring.The load frequency and amplitude is inversely proportional to damping factor.(4)Conduct a friction and wear comparative experiment on leaf spring. Spray tin bronze powder on leaf spring surface, and determine the coating powder not only can greatly reduces the amount of wear of the leaf spring but also makes the friction coefficient more appropriate, ensuring the damping effect while improving the fatigue life of the leaf spring.(5)Carry out a goal driven optimization analysis on leaf spring, obtain the optimized parameters and learn that optimized leaf spring model meet the operating requirement through finite element analysis.The paper determines the selection and sizes of the damping, and the finite element analysis indicate that the design of leaf spring structure is reasonable, safety factor is high, and the vibration reduction scheme is feasible. The friction and wear experiment indicate that tin bronze powder coating not only can greatly reduces the amount of wear of the leaf spring but also can lower friction coefficient, ensuring the damping effect while improving the fatigue life of leaf spring.