Research On Online Monitoring Technology Of Transmission Shaft Coupling Accuracy

Transmission shaft is an important component of rotating machinery.When the transmission shaft is assembled and adjusted,the coupling misalignment will occur during the operation of the equipment,which seriously affects the operation of the mechanical equipment,increase the wear of the components,lead to increase power consumption and even the failure of the shaft.The on-line monitoring technology of transmission shaft coupling has become a research hotspot at the present stage.However,due to the lack of scientific evaluation method for the relationship between coupling misalignment and power loss,the on-line monitoring technology is often restricted by the setting of warning limits.It is of great significance to develop the scientific evaluation method and on-line monitoring technology of transmission shaft coupling misalignment.In this paper,the mathematical relationship between coupling misalignment of transmission shaft connection and motor power consumption is studied,the evaluation equation is established to solve the problem that it is impossible to evaluate whether the coupling misalignment of transmission shaft is too large,which is verified by simulation analysis and experiment.It can provide a basis for setting coupling misalignment interval of transmission system in on-line monitoring process.According to the analysis results,an online monitoring method based on wavefront sensing and aberration theory is proposed.Firstly,on the basis of summarizing the research status at home and abroad,the geometric equations of coupling misalignment and transfer torque are established,and the motion equation of transmission shaft is established by finite element analysis method,the dynamic equation is obtained.The mathematical relationship between coupling misalignment and the electromagnetic torque is obtained by taking coupling misalignment,transfer torque,bending moment and shear stress as intermediate variables.Finally,the mathematical model between coupling misalignment and power consumption is established.Secondly,the coupling model of transmission shaft is analyzed by static and dynamic simulation.The dynamics analysis shows that the transmission shaft will produce periodic alternating stress due to coupling misalignment in the initial stage of the motor.When the motor runs smoothly,the static analysis results show that the shear stress of the transmission shaft varies linearly with the coupling misalignment.The theoretical power loss is obtained by substituting the shear stress corresponding to the coupling misalignment into the mathematical model,and the relationship between the coupling misalignment and the power loss.Thirdly,the power consumption values of different coupling misalignment are obtained through experiments,which are compared with simulation analysis results,the experimental results and simulation results are consistent.Based on the least squares method,the fitting equation is obtained and the curve relationship between the shaft coupling misalignment and power loss,which provides data support for on-line monitoring and warning limits.Finally,on the basis of Hartmann sensing technology,laser collimation system,microlens array and CCD camera are used to build the receiving device,and the spot offset is extracted by digital image processing method.The line misalignment and angle misalignment of the transmission system are analyzed and calculated,according to the established mathematical relationship to further evaluate the power loss,and finally achieve the online monitoring.