Effect Of Hammerhead Angle On Mechanical Properties Of Wheel Crusher Hammer Shaft Assembly

Wheel crusher is located in the slot of the coal mine underground mining face,and crushes the large piece of raw coal conveyed by the bridge transfer machine.The hammer shaft assembly of the crusher is the execution component of the wheel crusher.The energy transmitted from the power unit is transmitted to the hammer body through the hammer shaft,and the hammer head is rotated rapidly to achieve impact and break the coal.Statistics show that the failure rate of the hammer shaft assembly and transmission accounts for more than 80% of the total failure,and the hammer wear is severe and easy to lose is one of the main failure modes.Therefore,this study focuses on the analysis of the force at the hammer head,which is of great significance to the structural improvement of the hammer crusher assembly and the improvement of the reliability of the whole machine.Based on the PLM4000 crusher model,this paper firstly uses the theoretical method to derive the tangential force formula at the hammer head and calculatesthe magnitude of the tangential force when crushing materials of different particle sizes.In addition,the theoretical method is used to calculate the value of the load and friction applied to each outer surface during the crushing process of the hammer.Using APDL parametric modeling method,three hammerheads with different edge angles were established,and dynamic simulation and analysis were performed using ANSYS/LS-DYNA.Through the stress-strain cloud diagram of the hammer shaft assembly,we can see the changes in the force and deformation at the hammer head at different times.In addition,carefully analyze the force-time curve of the two-way force and resultant force between the hammer head and the material,as well as the variation coefficient of the contact force between the hammer head and the hammer body.The analysis results show that compared with the existing middle-edged hammerhead,the average contact force between hammers and the material of the large-edged angle hammer head and the small-edged angle is reduced by 4.5% and increased by 6.69%;the variation coefficient of the contact force with the hammer also decreases with the increase of the angle of the blade,from 0.145 of the small blade angle to0.077 of the large one.That is to say,appropriately increasing the angle of the corner can significantly reduce the load fluctuation of the hammer and the hammer.Finally,hammer heads with different blade angles are used to break materials with the same particle size.The results show that the larger the angle ofthe blade angle,the smaller the tangential force at the hammer head,that is,the increase of the blade angle will affect the breaking ability of the hammer.Therefore,it is possible to comprehensively consider these two aspects when improving the structure of the hammer.The research results of this subject provide an important reference for the subsequent optimization design of the wheel crusher assembly.