Study On Lightweight Design And Startup Characteristics Of Bucket Elevator

As a common bulk material lifting and transportation equipment,bucket elevator is widely used in mining,agricultural processing and other fields.It has the advantages of good continuity and fast vertical lifting speed.However,the bucket elevator commonly used at present is bulky and bulky;Most of its driving modes are driven directly by motor,which has large starting impact,resulting in high failure rate and short service life of key parts.This subject takes NE100 series bucket elevator as the research object,deeply studies its mechanical characteristics,carries out lightweight design for the key structural parts of the elevator,simplifies the structure and saves manufacturing materials;The starting characteristics of bucket elevator are studied,and the corresponding optimization scheme is put forward to improve the impact condition when the elevator is started and prolong the service life.The main work and research results of this thesis are as follows:(1)The whole bucket elevator is designed,calculated and analyzed,and the main components are selected;The three-dimensional model of bucket elevator is established,the static characteristics of important components such as traction chain,sprocket,spindle and dustpan are analyzed,and the mechanical characteristics such as stress and strain are verified;Using the topology optimization method,the lightweight optimization design of key components such as intermediate support joint and sprocket is carried out.The weight is reduced by 34.7% and 15% respectively,and the maximum stress is increased by 23 mpa and 2MPa respectively.The mechanical properties of the optimized structure are verified to meet the reliability requirements.(2)The main shaft model is established,the mass matrix and stiffness matrix of a single node are derived,and the parameters such as shear force,bending moment,inertia force and torque of the main shaft are obtained;The dynamic equation of the spindle system is established,and the natural frequency and vibration mode of the spindle are obtained;The dynamic model of the main shaft system is established by using ADAMS,and the relevant kinematic curves of the main shaft,roller,chain and dustpan are obtained.The dynamic characteristics of the main shaft system of the bucket elevator are analyzed,and the impact mechanical characteristics of the main shaft when the chain is stuck are studied.The results show that the impact force on the main shaft is within the allowable range and will not reduce the reliability of the system.(3)The mechanical characteristics of asynchronous motor for bucket elevator are studied,and the relationship between starting current,voltage and resistance is revealed;The dynamic equation and Simulink simulation model of the lifting chain system are established,and the state equation of the lifting chain system is derived.The performance difference between the direct drive of the motor and the start-up of the hydraulic coupler is compared and analyzed.The analysis shows that the increase of the hydraulic coupler is conducive to the start-up characteristics of the lifting system,the start-up time is reduced,the start-up current is reduced by 10%,and the maximum torque is reduced by two-thirds;The main shaft vibration signals of the hoist before and after the hydraulic coupler is added are collected and tested.The comparison results show that the vibration is significantly reduced when starting after the hydraulic coupler is added,which verifies the effectiveness of the scheme of adding hydraulic couplers.There are 80 pictures,8 tables and 69 references in this thesis.