Modeling And Dynamics Analysis Of Hypoid Gear For Vehicle

Hypoid gear has some advantages such as large overlap coefficient, stable ratio, smallershock and noise, higher carrying capacity, longer service life comparing with other bevel gear,moreover, its characteristic of offset between center can be utilized for lowing the gravitycenter or rising the through capacity of a vehicle.In this paper, a kind of new numeral, explicit tooth profile modals of hypoid gears isconstructed based on surface fitting technique, the models can be used for tooth contactanalyzing (TCA) or dynamitic analyzing. The main contents of this paper are followings:Firstly, some discrete tooth surface points be get accurately from the cutting trajectory invirtual manufacturing process, numeral tooth profile modals are re-constructed according tothese point’s coordinates and using NURBS surface fitting technique. Because the modalshave explicit formula instead of complicated, implicit formula, they can be used for TCA ofhypoid gear conveniently. In this paper,66modal points of each gear surface are used forsurface fitting, the fitting error is about in the level of10-3mm.Secondly, TCA programs based on the NURBS digital modals of hypoid gear arepresented according to the theory of gear meshing, including the formula or calculatingmethods for the first and second order contact parameters, contact point position, contacttrajectory and contact region and motion error curve. The results of TCA analysis are verifiedby comparing with the results of the finite element analysis and the Gleason methods.Lastly, the statics and dynamics of the hypoid gear are carried out using Adams. In orderto test out the influences on of fitting error on the statics and dynamics, the impact contactmodal with force constraint is used for constructing the motion relationship instead of thecontact modal with geometric constraint. The angular velocity and acceleration of gears,meshing force and torque are calculated, the results are analyzed by comparing with theresults of theoretic calculation. This work not only verifies the rationality of TCA methodsbased on tooth reconstructing technique presented in the paper, but also provides a newmethod for the statics and dynamics analyzing of the hypoid gear.