Characteristic Study Of Efficiency And Temperature Field Of Cutting Transmission System For 1200kW Shearer

With the rapid development in economy of C hina,the energy demand is increasing and the problem of energy supply is becoming more and more serious,and the coal based energy as the first position is unshakable,coal yield and quality is d irectly related to the speed of development and the development level of national economy construction.Longwall shearer is the key equipment to achieve high efficiency of mining,improve the working conditions and reduce the major coal mine accidents.As an important part of the shearer,the cutting part completes power transfer.The cutting transmission system of shear have some shortcomings,including large power loss and low efficiency.When the shearer is working and the angle of rocker arm is increasing,lubrication state of gears gets bad.Meanwhile the power loss increases and the temperature of tooth surface rises rapidly,which seriously influence the reliability of cutting drive system.This topic is the important component of the national major basic research program(973 project)of China.In order to improve the life and reliability of the shearer,this paper analyzes the efficiency and temperature field of cutting transmission system of 1200 kW shearer.The main work contents:(1)Based on a certain type of 1200 kW shearer,SMIULINK model of power loss and efficiency of cutting transmission system are established;the influence of speed,torque oil temperature and immersion depth are analyzed.(2)Considering the internal structure and heat transfer between all elements of the cutting transmission system of shearer,every element is handled as a node and the steady state thermal network model of reducer of cutting system is established;the temperature of every element can be obtained and some factors,which influence the temperature,are analyzed.(3)Based on the friction principle of gear meshing,the convective heat transfer coefficient of gear is calculated;finite element model of the steady temperature field of the gear is established in COMSOL,through setting gear heat balance equations and boundary conditions;each gear temperature field distribution is analyzed under different conditions;some factors of temperature field are also studied(4)Based on the thermal network model of reducer and considering the material parameters and convection parameters changes with temperature,the transient thermal network of cutting transmission system of is established;time can be gotten when node's temperature reaches equilibrium and the longest working hours of gears under the worst conditions can be obtained;the lubrication system can be optimized and improved to improve the life and reliability of the shearer.Power loss of transmission system can be reduced and efficiency can be improved by optimizing the speed,toqure,immersion depth and the flow of coling system;according to the maximum allowable working time,working life and reliability of the shearer can be improved by changing the way of gear lubrication and cooling,when the rocker is located at different swing angles.