Dynamic Analysis Of Mutistage Gear Transmission System Of Large Cement Equipment

New type dry-process production can be summarized as "two grinding and one burning" of three links.'Two grinding",which means the ball mill and roller mill (vertical mill),is the course of the preparation of raw material and cement grinding. "One burning" is the process which the raw material is calcined into cement clinker in a rotary kiln. The technical performance and operating status of production equipment decide the quality, yield and cost of the cement. Multi-gear transmission system is an important part of cement production equipment. Vibration and noise of the transmission system is the key factor that impact system reliability, life and the operational environment.Multi-gear transmission system consists of the motor, coupling, reducer, and working machine. Gear drive system dynamic incentive is the basic reason that the gear system generate vibration and noise. So, in-depth dynamics study on the multi-gear transmission system, analyzing the vibration mechanism, proposing accordingly improvement measures and designing excellent dynamic performance of the gear transmission installations which to hold the inherent dynamic characteristics in a given scope, thus the stability and reliability of large cement equipment will be assured. In this paper, based on the theory of gear dynamic analysis, study the dynamic characteristics of the drive system of rotary kiln and vertical mill, and the main results are as follows:1.According to the characteristics transmission of rotary kiln and vertical mill, establish the kinetics models on torsional vibration of their drive system respectively with lumped parameter method, calculate the parameters of the system components such as moments of inertia, the axis torsion stiffness and gear meshing stiffness; Work out the natural frequency and mode of the drive system with the conditions of discrete object's simple harmonic vibration.2.Study the inherent characteristics of the drive system's torsional vibration. Sum up the natural frequency of the band characteristics and the low natural frequency's impact on transmission. Reveal the two vibration mode of the vertical mill transmission: planetary gear vibration mode and torsional vibration mode.3.Analyse the excitation frequency of drive system, consider the interior exciting force caused by time-variable stiffness, gear error and meshing shock that cause the vibration of gear transmission ,and research the resonance failure of multi-gear transmission to provide theoretic help to ensure the safe and stable operation of production equipment.4.Confirm that changes of natural frequency has a contrary trend with changes of the system components' rotational inertia, but same to the changes of the stiffness with sensitivity analysis.Quantitatively understand the realitionship between the structure and geometric parameters of the system and the natural frequency,which can direct the modification of structural dynamics and get the most sensitive parts of amending the dynamic characteristics and structural parameters , so as to enhance and improve the transmission's natural characteristics.