Dynamic And Stability Analysis Of Self-mobile Crusher With Slow-varying Mass

The main energy structure of China is coal because of few oil and gas. The fact that the open-pit coal mine mining rate is much lower than the developed countries in the world has become the main factor to restrict the development of our energy structure. In order to improve the open-pit coal mine mining rate, the predominant mining equipment like crushers, are developing diversely. However, most of the material’s weight is so big that the equipment will be influenced greatly by the impact. The change of blanking time and blanking quantities will affect the overturning stability of the system. At the same time, the material impact and the slow-varying mass can cause strong nonlinearity to the system. As the time goes on, some stress fatigue parts may cause fatigue damage. Therefore, it is becoming quite urgent to control the blanking quantities in an unit time when the large crusher are operating. Therefore, it is necessary to establish a slow varying-mass dynamic model more precisely when the large crushers are on the design.This paper were based on the Newton mechanics and finite element theory, and established a single degree of freedom model and multiple degrees of freedom model as well as the practical engineering structure model for research. The work of the paper is useful for structure design of the crushers and the blanking improvement. The main contents of the paper are as follows:(1) The dynamic model with slow-varying mass and the usual dynamic equation was built. The influence of the relative damping and relative mass on the system were analyzed. The stability of system with different mass ratios was studied. The result was obtained that the blanking quantities should be strictly controlled in the factual blanking progress to decrease the equipment damage caused by unstable vibration.(2) The crushers were simplified into simple beam structure with multiple degrees of freedom. The gravity load was applied to nodes. The influence of different parameters of the system was studied. Finally, the overturning stability of the system under different road surface hardness was studied.(3) The dynamic of the self-mobile crusher in terms of the slow-varying mass was analyzed. The conclusion that the nonlinearity of response is mainly caused by the impact of blanking was obtained by comparison, and the paper also came to the conclusion that the change of blanking quantities in an unit time may influence the signal of the vibration’s strength.(4) The single degree of freedom blanking system experimental scheme was designed with the impact of the material and the slow-varying mass of the system taken into consideration. B&K was used to measure the signal of the blanking system’s vibration. At the same time, the slow-varying mass model dynamic equation was built in theory, and the equation was solved numerically. The feasibility of the theoretical derivation was testified by the comparison between the experimental and numerical results.