Study On Elastohydrodynamic Lubrication And Dynamics Contact Of Double Involute Gear

Double involute gear is a new type of gear which was put forward based on therearch of involute gear and double circular arc gear, its tooth profile was formed bytwo order decorate points involute and tooth waist transition curve which connect thetwo involute, when the double involute gear running, due to the tooth flank areawithout contact at the tooth waist, avoid the defects of earlier node corrosion likecommon involute gear, at the same time, it combines the sublevel ideas of the doublecircular arc gear, thickness and bending strength of tooth root have an obvious increasecompared with the common involute gear, the current research about double involutegear was mainly about bending stress of tooth and tooth surface contact stress underthe static condition, the researches does not consider the role of the lubricating oil filmexists between the contact tooth surfaces, in order to promote the new gear used earlier,its lubricating characteristics and the study of the dynamic contact are necessary. Inthis paper, from the gear tooth surface meshing principle and envelope principle, theequation of double involute gear tooth surface is derived, based on the lubricationcharacteristics of double involute gear with dynamic contact condition. Based on thetheory of elastic hydrodynamic lubrication, the lubrication characteristics of doubleinvolute gear and lubrication equations are derived.In the3d drawing software“solidworks”, the double involute gear model was established by the method ofparametric modeling, and dynamic contact was analysised in ANSYS. The concreteresearch content as follows:1. Based on surface formation principle and the space meshing theory of thedouble involute gear tooth, the basic parameters of tools which used to process doubleinvolute gear was ensured, according to the geometrical relationship between cutter tooth surface equation, based on envelope principle, the double involute gear toothsurface equation was derived, for the3d drawing software in precise create doubleinvolute gear model lay the foundation.2. A line contact elastohydrodynamic lubrication Reynolds equation wasestablished, on the condition of assumption isothermal, the simplification of Reynoldsequation has been established for line contact steady-state isothermal Reynoldsequation; Due to elastic deformation exist at the contact area, therefore film thicknessequation, viscous pressure equation, pressure equation and load equation wasestablished on the basis of the elastic and geometric simulation.3. In view of geometry relations between the two tooth surface during the doubleinvolute gear meshing, equivalent the meshing into two reverse contact of two coneroller for analysis, based on the two tooth surface meshing geometric relations, thelongest contact line and meshes into and out of sublevel ellipse parameter wascalculated, and the parameters of ellipse of several special points which were extractedat meshes into and out process was calculated; dimensionless equations of doubleinvolute gear about steady state elastohydrodynamic lubrication of line contact,multiple simultaneous grid method is used to solve the above dimensionless equation,it is concluded that the minimum oil film thickness and oil film pressure center alongthe line of action, select key points on the meshing line, and to solve pressuredistribution and film thickness of the key points.4. Using new tooth surface equation, a three-dimensional model of the doubleinvolute gear was established, dynamic contact was analysised use ANSYS/ls-dyna.