Dynamic Characteristics Analysis Of Hoist System For Electric Mining Shovel

Having a great excavating capacity and high efficiency,Electric mining shovel(EMS)is widely used in open pit mine for excavating and loading the blasted material onto the mining dump truck.With the domestic deepening of supply side reform and readjusting energy industrial structure,more and more large open pit mines are developed in Xin Jiang and Nei Menggu province.Therefore,EMS has broad market prospects.However,the hoist system of EMS always occurs excessive vibration and leads to premature failure of some components in present work.Because of the complex structure and coupling relationships,it's difficult to establish the dynamic model of EMS hoist system.Now the shortage of suitable dynamic model has been the bottleneck of reducing vibration with EMS hoist system.Taking the EMS which standard dipper capacity is 55 m~3 as an example in the paper,a electromechanical coupling dynamic model was established using hierarchical modeling method.Based on the mathematic model,the natural frequencies and vibration modes were calculated and summarized,then the sensitivity of natural frequencies to componment parameters in the system was analyzed.According to the simulated motor ripple torque,the dynamic response of EMS hoist system was researched and contrasted with measured data for proving its validity.The dynamic model and study results can provide support for reducing vibration design of EMS hoist system.The main work in the paper is shown as follows:(1)A electromechanical coupling dynamic mode was established based on hierarchical modeling method,which can be decoupled to four coupled subsystems.Both the subsystems were coupled together by coupling connection,bolt connection and bearing connection,while every subsystem contains coupling connections,such as gear mesh and flexible connection couplings.(2)Study on natural characteristics of EMS hoist system.Baesd on the dynamic model of mechanical part in EMS hoist system,the natural frequencies were calculated and the vibration modes were summarized and classified.In order to find the parameters affected the natural frequencies greater and focus on these parameters when design the EMS hoist system for reducing vibration,the sensitivity of natural frequencies to componment parameters in the system was researched.(3)Study on dynamic responses of EMS hoist system.According to the actual driving torque simulated by VC system,the dynamic responses of EMS hoist system was calculated.After analyzing the dynamic responses in time domain and frequency domain,the vibration laws of EMS hoist system was obtained for learning the system vibration.Finally,the response data was contrasted by measurement for proving the validity of the dynamic model.