Research On Cutting Transmission System Of Longwall Shearer With Varying Cutting Speed

Longwall shearer is the key equipment for the mine exploitation on the workplace, its reliability and intelligence having a material influence on safety and efficiency product of the coal. The ratio of deep-dangerous coal mining is growing with the shallow coal exhausted, which makes our country mining industry desperately need unmanned mining epuipment to improve mining efficiency and reduce the potential miner casualty accidents. The adaptability of traditional longwall shearer is bad under complex coal seam because only the traction speed can be adjusted while the drum rotational speed not, which doesn't conform the requirement of unmanned mining equipment intelligentized cutting. So that, based on ”973” research program, a longwall shearer cutting transmission(LSCT-V) system with varying cutting speed is proposed in this paper, the main research works include:(1) Based on speed coupled schematic of differential 2K-H epicyclic gears(DEG), a new LSCT-V system is presented, and the transmission parameters of this system are matched; the formular between drum speed and frequency of converter motor is given, which provides a basis to regulate the cutting speed of LSCT-V system.(2) The dynamic equations of LSCT-V system that include cutting motor rotor and drum are established by use of lumped parameter method according to the designed system; the calculation method of dynamic parameters is provided, and the influence of time varying meshing stiffness that affected by the number of terms of Fourier series expansions is analysed.(3) The kinematic model of LSCT-V is built in AMESim, and the speed regulation characteristics of converter motor are researched under step signal?ramp signals with different slopes and sinusoidal signals with different varying frequencies, which provide references to regulate motor speed.(4) The free-vibration equation without damping of DEG is founded and the natural characteristics are solved; the effects of natural frequencies that influenced by meshing stiffness and support stiffness are studied, and the formular of meshing frequency of DEG is derivated.(5) First of all, the dynamic models of traditional longwall shearer cutting transmission(LSCT) system and LSCT-V system are created in AMESim; the relative linear displacements and contact forces of gear pairs in these two models when working with constant cutting speed are constrasted separately under step load; secondly, the relative linear displacements and contact forces of gear pairs in these two models when working with varying cutting speed are compared respectively under step load; finally, the dynamic response of LSCT-V system that working with constant cutting speed under pulse loads with different frequencies is analysed.