| As the characteristic of high power output,high efficiency,stable transmission ratio,reliable operation and long life etc,gear transmission system has been widely used in the field of equipment manufacturing and national defense industry.It can be used to transmit rotary motion and momentum between any two shafts,depending on the meshing contact of tooth profiles.Gear mechanism can be divided into constant transmission radio gear mechanism and gear mechanism with variable transmission radio,and the non-circular gear mechanism is mainly used for some special occasions.As a new type of non-circle gear,curve-face gear transmission,which can realized variable transmission radio transmission,has triple characteristics of non-circular gear,face gear and space cylindrical cam mechanism,and it makes that curve-face gear transmission can realize variable speed transmission like space cylindrical cam and high efficiency precision transmission like face gear.It has the potential application in the fields of aerospace,engineering machinery,textile machinery,agricultural machinery,etc.Therefore,the time-varying meshing characteristics research and design about the curve-face gear drive are of great theoretical significance and potential engineering application value.Regarding curve-face gear transmission as research object,some relevant research are carried out,including time-varying meshing theory of curve-face gear transmission,parametric design method,analysis of time-varying meshing characteristic,manufacturing technology,measurement,experimental verification and evaluation.The main research contents of this paper are summarized as follows:(1)The time-varying meshing basic theory and characteristics analysis of curve-face gear transmission are studied.Based on the space engagement principle and the gear meshing theory,the transmission principle of curve-face gear transmission is discussed;the basic motion feature of curve-face gear transmission is analyzed;the time-varying meshing analysis model about kinematics,geometry and mechanics of curve-face gear transmission are built;the influence of the basic parameters of the curve-face gear pair on its time-varying meshing transmission characteristics are explored,and the time-varying meshing motion characteristics of the curve-face gear transmission are obtained,like transmission radio,angular displacement,angular velocity,angular acceleration and so on;the time-varying geometric characteristics,like parameters of tooth surface discretization,tooth profile curvature,tooth surface and tooth width,are received,and the time-varying meshing characteristic mechanism of curve-face gear transmission are revealed.(2)The design method of time-varying meshing parameters of the curve-face gear transmission is studied.Based on the gear space engagement principle and the virtual design technology of tooth surface forming,the basic design parameters of the curve-face gear transmission are determined;the design and matching criterion of the curve-face gear drive mode are established;the method for solving the tooth surface of the curve-face gear is discussed;the precise tooth shape and 3D model of the curve-face gear pair are obtained.Combination of accurate discretization technique about the tooth surface characteristic parameters,such as inner and external tooth profile,addendum curve,transition curve and the contact line of curve-face gear,through the organic combination of the exact coordinate model of the discretized tooth surface,time-varying meshing characteristic analysis,tooth manufacture and measurement evaluation,the theoretical bases of the design and manufacture,accuracy detection and evaluation of the curve-face gear are obtained.(3)The design method of time-varying meshing dynamic model of the curve-face gear transmission is studied.Based on the Lagrange bond graph theory and elastohydrodynamic lubrication theory,the boundary conditions and the vibration excitation source of the curve-face gear transmission system are analyzed;the dynamic modeling method of the curve-face gear under dynamic characteristics is discussed.Considering the influences of the key factors such as dynamic engagement force,friction factor,oil film thickness,spatial relative velocity and dynamic load distribution,the mathematical model of mechanical dynamic efficiency of the curve-face gear drive in the elastic fluid lubrication state is established;the influence of the basic parameters of the curve-face gear pair on the dynamic variation rule,like the time-varying meshing vibration response and dynamic meshing efficiency,is explored;the mechanism of time-varying meshing dynamic characteristics of curve-face gear transmission is revealed.(4)The experiment and verification of the time-varying meshing theory of the curve-face gear transmission are studied.Combination of gear manufacturing and gear drive test technology,the feasibility of five-axis CNC machining method for machining curve-face gear is discussed.The calculation and evaluation method of tooth surface precision of curve-face gear are established.An integrated experimental test platform of the curve-face gear transmission suited for a series of parameter changes is set up.The correctness and feasibility of the theory and design method of the transmission principle,the method of design and manufacturing,virtual simulation technology,precision detection and evaluation method,time-varying meshing transmission characteristic analysis are proved. |
