Research On Key Technologies Of Vibration And Noise Reduction In Worm And Helical Gear Drive

With the continuous development of smart products,worm and helical gear transmission pairs with the advantages of large transmission ratio,compact structure,reverse self-locking and good manufacturability are increasingly used in smart homes,service robots and autonomous vehicles.However,the worm helical gear transmission pair has the characteristics of point contact on the tooth surface,small number of meshing teeth at the same time,and high relative sliding speed,which results in its small load capacity,low efficiency,large vibration and noise,which restricts the high quality of the worm helical gear transmission pair.Bottleneck technology for development.The thesis combines the sub-tasks of the scientific and technological achievements transformation project of "Small Modulus Worm Helical Gear Transmission Key Technology Research" of Shenzhen XX Company,and takes the vibration and noise reduction of the small modulus involute helical gear transmission pair as the research objective,combined with theoretical analysis,Numerical calculations,finite element simulations and bench tests have systematically studied the dynamic characteristics of the transmission pair under the action of multiple factors such as material properties,structural parameters,modification rules,meshing errors,and load conditions,revealing the vibration and noise of the transmission pair.The influence mechanism and related research results have theoretical guiding significance and engineering application value for the vibration and noise reduction of the transmission pair.The main research contents of this paper are as follows:(1)Considering the meshing characteristics of the worm helical gear transmission pair,based on the potential energy method and the integral method,the mathematical models of the bending stiffness,shear stiffness,axial compression stiffness,Hertz contact stiffness and base stiffness of the transmission pair are derived,and the single and double teeth are established.Synthesizing the time-varying meshing stiffness,the finite element method is used to compare and verify the correctness of the model,and the influence of materials,pressure angle and helix angle on the meshing stiffness of the transmission pair is further analyzed.(2)Considering nonlinear factors such as time-varying meshing stiffness,tooth backlash and meshing error,a two-degree-of-freedom pure torsion nonlinear dynamics model of worm helical gear transmission pair is established by lumped parameter method,and a fourth-order variable step Runge-Kutta method is adopted.The dynamic differential equations are solved,and the influence of the dimensionless backlash,load conditions and meshing damping factors on the nonlinear dynamic characteristics of the transmission system is analyzed.(3)Based on the three elements of involute gear modification,the root mean square of the torsional vibration acceleration of the transmission pair is used as the objective function,and the curve parameters of the exponential modification curve and the parabolic modification curve are optimized,and the maximum modification amount and modification are analyzed.The influence law of the shape length on the modification effect of the transmission pair.(4)Based on the modularization concept,a small modulus helical gear transmission performance test bench was designed,the software and hardware system debugging of the related test benches were completed,the experimental plan was formulated,and the preparation and testing of test samples were completed.The different tooth side clearances,The vibration and noise of the transmission pair under load and speed and the change rule of transmission efficiency,and the effect of different worm and helical gear modification amounts on the vibration and noise value of the product is verified in the car seat level adjuster,and the influence law of each physical quantity on the vibration and noise of the transmission pair was revealed.