Research On The Damage Mechanism And Strength Calculation Method Of Double-Telescopic Column Guide Ring Of Hydraulic Support

With the advancement of coal mining technology,hydraulic supports are developing towards super-large mining height and super-large support resistance,which puts higher and higher requirements on hydraulic support columns.The big mining height hydraulic support column adopts double telescopic or even three telescopic columns.At present,basic research on super-long and super-large-bore multi-telescopic columns is still lacking,which makes the design of the columns lack theoretical support.As a key component of the column,the guide ring is the guarantee of the guiding and supporting performance of the column.In the design of super long and large cylinder bore columns,how to ensure the safe and reliable operation of the guide ring is an important issue.At present,there is no clear conclusion about the damage mechanism of the guide ring,and the relevant basic research is lacking.In the design of the column,the traditional method of calculating the stress of the guide ring can only solve the average stress of the guide ring,and the worst part of the stress state of the guide ring is at the edge.How to solve the stress at the edge of the guide ring is also needed to be solved during the design of the column important topic.Based on the above reasons,this thesis studies the damage mechanism and stress calculation method of the guide ring.Firstly,the stress on the cross section of the piston guide ring and the guide sleeve guide ring with the highest stress is analyzed,and the column and guide ring are subjected to finite element simulation analysis under eccentric load conditions.The simulation results prove that the force analysis It is concluded that the edge of the guide ring will produce local bulge under the action of friction.According to the simulation results,the compression amount and stress of the bottom cylinder guide ring are in the width direction with the middle and small ends increasing.The compression amount and stress of the middle cylinder guide ring change monotonously along the width direction.The compression amount and stress of the five guide rings on the fixed section vary non-linearly along the axial direction.The compression amount and stress of the outermost guide ring are much greater than those of the middle guide ring.Secondly,in order to study the damage mechanism of the guide ring,the wear amount and wear angle of the severely worn part of the failed guide ring were measured.The angle between the wear surface of the largest wear part and the radial direction of the column was between 33° and 45°.Furthermore,the maximum shear stress value and direction of the five guide ring edges were solved by finite element simulation.The angle between the maximum shear stress direction and the radial direction of the column was 33°≤θ≤45°,and the guide ring was worn The angle basically matches.Moreover,the maximum shear stress value of the uppermost and lowermost guide ring of the middle cylinder exceeds or approaches the shear strength of the guide ring.It is proved that the maximum shear stress is directly related to the damage of the guide ring.Then,a guide ring wear model was established and simulated.The results showed that after the guide ring wears,the stress level of the guide ring increases,which will increase the guide ring wear.Finally,a calculation method for solving the stress of the guide ring is derived.The new method establishes the relationship between the stress of the guide ring,the width of the guide ring and its fit gap,and it can calculate the stress of any point on the width of the guide ring.The calculated results of traditional and new method were also compared.The new method can be used to calculate the stress when the width of guide ring or the fit clearance is changed.So it has wider adaptability.