Lubrication Analysis And Optimization Design Of Straight Profile Hourglass Worm Gear

As a worm drive with excellent performance,the straight profile hourglass worm gear has the advantages of a large number of meshing teeth,double line meshing of meshing tooth surfaces,and easy formation of fluid flow lubrication by meshing transmission.However,due to the limitations of research technology and cost,its excellent performance has not been fully utilized.In order to further improve the lubrication performance and contact performance of the straight profiled worm gear,the thesis mainly studied the meshing theory,elastohydrodynamic lubrication analysis,parameter optimization design and finite element contact analysis of the straight profiled worm gear.The specific work is as follows: :1.Establish the tooth surface equations and contact line equations for straight profile toroidal worm gears.The mathematical model of the straight profiled worm gear is the basis of lubrication and contact research.Based on the principle of conjugate surface kinematics,the thesis deduced the worm tooth surface equation,worm gear tooth surface equation,tooth surface contact line equation and tooth surface contact parameter.The worm gear tooth surface equation was solved and the worm gear tooth surface discrete model was obtained.2.Elastohydrodynamic lubrication analysis of straight profiled worm gears.Excellent lubrication conditions can reduce tooth surface friction loss,improve transmission efficiency and prevent tooth surface failure.According to the theory of line contact elastic fluid dynamic pressure lubrication,an elastohydrodynamic lubrication model of a straight profiled worm gear pair is established.The minimum film thickness formula of linear contact elastic flow lubrication is the calculation basis,and the minimum film thickness of the straight profiled worm gear pairing process is solved with the change of each main parameter,and analyzed the influence of the main parameters on the minimum oil film thickness of the straight profiled worm drive.3.Parameter optimization design of straight profiled worm gear.Based on the meshing theory and elastohydrodynamic lubrication analysis results of the straight-profile toroidal worm gear set described above,the optimization parameters are determined to improve the lubrication performance and contact performance of the straight-profile toroidal worm gear.An improved particle swarm optimization algorithm is used to perform the main parameters.The design was optimized,and the results before and after the optimization were compared with the lubrication performance to verify the reliability of the results.4.Finite element contact analysis before and after optimization of a straight profiled worm gear pair.Based on the solution results of the tooth surface equation in the second chapter.The paper completed the three-dimensional solid modeling of the straight profiled worm gear pair,and compared the finite element contact analysis of the straight profiled worm gear pair model before and after optimization.The results showed that the tooth surface of the straight profiled worm gear is in double line contact and match with the theoretical contact line distribution state,which verifies the correctness of the worm's auxiliary physical shape.After the parameter optimization,the maximum contact stress of the meshing tooth surface is reduced,the contact stress distribution is more uniform,and contact of the worm gear has been improved.