Research On Dynamic Characteristics Of Mine Hoist Based On Constant Deceleration Braking Condition

Mine hoist is a key equipment in coal mining.It undertakes the task of lifting or lowering the staff,coal and mining equipment.Therefore,it exerts an important influence on the production efficiency and safety in coal mining.Emergency braking is the most important safety safeguard of the hoist.When accident occurs,the braking system can avoid it.Otherwise,it is possible to cause serious loss and threat the safety of coal mining.Because of the flexible characteristics of the wire rope,the large inertia load has a huge impact and vibration to the hoist during the emergency braking,which may cause the breaking and skidding of the rope.Constant deceleration braking has been widely used in lifting equipment because it has smaller impact and better stability.With the increasing of coal mining depth,lifting load,speed and efficient,the hoist is sensitive to changes of hoisting parameters.Therefore,researching dynamic characteristics of the rope tension and the cage vibration have theoretical and practical significance.In order to obtain the hoist?s dynamic characteristics in braking,the following works were mainly carried out in this thesis.1.The modeling method of hoist was researched,and a rigid flexible coupling dynamic simulation model of floor-type multi-rope friction hoist was modeling,simulation model was verified by the test data.Firstly,the hoist of JKMD3.25×4(II)was taken as the object,and the 3D geometric model was established by using the software of SolidWorks.Secondly,the rope model of finite element flexible was finished by using ANSYS and RecurDyn/FFLex.Finally the rigid flexible coupling dynamic model of the hoist was established.On this foundation,the cage vibration had been tested under the normal working condition and the constant deceleration braking.Through comparison test and simulation results,the correctness of the simulation model was verified.2.The influence of different hoisting parameters to the dynamic characteristics had been studied in the constant deceleration braking.Using the control variable method,the hoisting parameters' influence to the rope tension and the cage vibration was analyzed,in which the parameters include hoisting load,hoisting speed,braking deceleration and braking curve.So the response law of the hoist dynamic characteristics was obtained in the constant deceleration braking process.the results show that:(1)the parameters of load,deceleration and braking curve were the main factors that affect the stability of the braking,the rope tension and the cage vibration,but the hoisting speed has little influence.(2)Comparing with the parking stage,the trend of slipping during the braking stage was more obvious under the condition of heavy load and lower.(3)The variation and variance ratio of the deceleration were one of the key factors that affect the braking stability,the rope tension and the cage vibration.Therefore,it can achieve the smooth braking of hoist by changing the variation and variance ratio of deceleration.