Design And Analysis Of Eccentric Straight And Helical Curve-face Gear Pair

The eccentric straight and helical curve-face gear pair is proposed as a new type of gear dive with variable transmission ratio based on the curve-face gear pair.It is composed of a non-circular gear and an eccentric curve-face gear.This gear pair can be divided into eccentric straight curve-face gear pair and eccentric helical curve-face gear pair according to the difference of non-circular gear.It combines the transmission characteristics of curve-face gear and eccentric gear,and can be used to transmit variable transmission ratio motion and power between intersecting axes,and the composite motion of output shaft can be realized by the eccentric helical curve-face gear.It has the potential application in the fields of engineering machinery,textile machinery,agricultural machinery,automobile,aerospace,etc.This issue derives from Natural Science Foundation of China: “Study on the design theory and manufacturing technology of variable transmission ratio face gear transmission mechanism(Project NO.51275537)”,and “Study on the design theory and experimental of variable transmission ratio composite transmission gear pair(Project NO.51675060)”.This paper put forward the eccentric straight and helical curve-face gear pair based the study of curve-face gear pair,and the purpose is to study the basic principle,geometric design criterion,meshing characteristic,software development,manufacturing processing method,evaluation method as well as experimental verification of eccentric straight and helical curve-face gear pair.The main research contents of this paper are summarized as follows:(1)The basic theory of eccentric straight and helical curve-face gear pair is studied.Adopting the gear meshing theory and space geometry,the basic transmission principle of eccentric straight and helical curve-face gear pair is discussed.The coordinate system and relation of basic parameters of eccentric straight and helical curve-face gear pair are established.The design criteria of pitch curve of eccentric straight and helical curve-face gear pair are obtained.The tooth surface equation of shaper cutter is analyzed,and the development trajectory of shaper cutter is obtained.The meshing equation and the tooth surface equation of eccentric straight and helical curve-face gear are derived.The mathematical model of tooth surface is obtained.(2)Meshing characteristics of eccentric straight and helical curve-face gear pair are studied.Adopting the differential geometry theory and tooth profile forming principle,the influence law of transmission ratio,angular displacement,angular velocity,angular acceleration,pressure angle,and motion parameters affected by the parameters(such as eccentricity,order,tooth number,modulus,helix angle of helical non-circular gear and eccentricity,order of eccentric helical curve-face gear)are discussed.The undercutting and pointing phenomenon of eccentric helical curve-face gear are analyzed,and the calculation formula of maximum outer radius and minimum inner are derived.Meanwhile,the influence law of tooth width of eccentric helical curve-face gear is obtained.(3)Auxiliary analysis software of eccentric straight and helical curve-face gear pair is studied.Adopting the hybrid programming of Visual Basic 6.0,Matlab and Solidworks,the auxiliary analysis software of eccentric straight and helical curve-face gear pair is designed,and it can realize the parameter design,the software design of characteristic analysis and simulation machining function of eccentric straight and helical curve-face gear pair.Besides,the processing method of 3D model of eccentric straight and helical curve-face gear pair is explored.Rapid analysis of complex characteristic and model of eccentric straight and helical curve-face gear pair is settled.(4)Experimental analysis of eccentric straight and helical curve-face gear pair is studied.Adopting modern processing technology and detection method,the manufacturing process of eccentric straight and helical curve-face gear pair is discussed by using the five-axis CNC maching method.The evaluation method of tooth surface of eccentric straight and helical curve-face gear pair is established.The transmission experiment device is designed and established.The experimental data of output torque,rotational speed and transmission ratio of eccentric straight and helical curve-face gear pair are obtained,and the correctness and feasibility of design method and principle of eccentric straight and helical curve-face gear pair are verified.