| The transmission system is the hub to transfer motion and power between the prime power system and the executive system.It is an indispensable part of transmission machinery,as well as light industrial machinery.With the development of manufacturing towards high,precision and sharp,there are higher requirements for the working performance,energy consumption,vibration and noise of transmission machinery.In order to achieve the purpose of large transmission ratio,light weight and uniform load,the globoidal cam transmission mechanism of planetary gear train is designed.Based on the design method of globoidal cam theory and ensuring the advantages of existing globoidal cam transmission and planetary gear transmission,the globoidal cam transmission mechanism of planetary gear train through transplantation innovation method is designed.The transmission ratio,meshing profile,pressure angle and transmission bearing capacity are researched.And the test prototype was manufactured.The main contents are as follows:(1)Resegloboidalh on motion continuity condition based on correct meshing condition and assembly conditionUsing the method of mechanism transformation,the calculation formula of transmission ratio,correct Meshing Conditions and assembly conditions of globoidal cam transmission mechanism of planetary gear train are deduced;The motion continuity conditions of the mechanism are studied by taking the envelope angle of inner and outer globoidal cam as the main parameters.According to the characteristics that the mechanism can realize multi-point meshing,the reasonable value of inner and outer cambered cam envelop angle is further given based on the minimum value of inner and outer cambered cam envelop angle.When the number of planetary gears,the number of planetary teeth and the number of teeth of inner and outer globoidal cam are determined,the variation law of envelope angle and meshing number of inner and outer globoidal cam is given.(2)Study on unified mathematical model of planetary gear tooth surfaceThe spatial contour surface of the new transmission mechanism is deeply studied,and a general mathematical model describing the spatial contour surface of the new transmission device is constructed for different spatial contour surfaces.Based on the space surface meshing theory,this thesis deduces the profile meshing equation of globoidal cam transmission of planetary gear train.Then,using the analysis method of rotation transformation tensor,the unified mathematical expression method of planetary gear tooth surface is established.On this basis,the contact line equation between the surface of rolling gear on planetary gear and inner and outer globoidal cam is deduced,and the tooth profile surface equation of inner and outer globoidal cam under different planetary gear tooth shapes is analyzed.The boundary curve equation and the calculation formula of induced normal curvature under different tooth profile surface equations are studied.By introducing transmission parameters,the influence of transmission parameters on the meshing characteristics of globoidal cam transmission of planetary gear train is analyzed.(3)Study on influencing factors and laws of pressure angle under different power take-off componentsIn the globoidal cam transmission mechanism of planetary gear train,when the inner globoidal cam is fixedly connected with the frame,it can be used as the power transmission component of the mechanism.The planetary gear connected to the planetary carrier is meshed with the inner and outer globoidal cams at the same time.Therefore,the planetary gear rotates while rotating,because the machine is a double pressure angle mechanism.Based on the pressure angle calculation theory of globoidal cam and the particularity of the transmission mechanism,this thesis deduces and analyzes the pressure angle formula in detail by taking the spherical planetary gear as an example.Through the orthogonal experiment of three factors and four levels,the effects of transmission ratio I,center distance a,planetary gear radius R and planetary gear radius r on the pressure angle are studied.The results show that the effect of the inlfluencing factors of the pressure angle has a two-way influence on the pressure angle between the inner and outer globoidal cams of the mechanism.(4)The influence law of transmission parameters on load distributionLoad analysis is the premise of studying the bearing capacity of transmission mechanism.Based on peeken’s resegloboidalh on transmission load distribution,this thesis deduces the calculation formula of load in planetary gear train globoidal cam transmission with a concise analysis method and considering the eccentric load phenomenon of cam along outer Globoidal,and analyzes the influence law of transmission parameters on load distribution.The stress distribution of multi-point meshing is explained by finite element analysis.According to the data of simulation calculation,the stress on the meshing planetary gear teeth is the largest,which is the focus of the follow-up overall stress improvement resegloboidalh.(5)Trial production of solid prototype based on 3D printing and NC machining test of inner and outer globoidal camThe three-dimensional model of globoidal cam transmission of planetary gear train is established by using motion simulation trajectory method and Creo 3.0.The feasibility of the design idea and method of globoidal cam transmission mechanism of planetary gear train is verified.Taking the spherical gear globoidal cam planetary drive as an example,through the combination of 3D printing and dmu65monoblock five axis NC machining of inner and outer globoidal cam,the space limitation of inner globoidal cam machining and the generation of CAD/CAM data are emphatically solved.The trial production of solid prototype is completed,which provides theoretical and technical support for the further research of the mechanism.In addition,in view of the problem that the meshing profile of planetary gear train globoidal cam transmission is a space undevelopable surface and it is difficult to machine,this thesis makes an innovative research on the structure of the transmission device,and puts forward a new squirrel cage structure of planetary gear train globoidal cam transmission device.In this thesis,the globoidal cam transmission of planetary gear train is systematically studied,which provides a theoretical basis for the optimal design of globoidal cam transmission mechanism of planetary gear train.The research is to promote the transformation of the organization from theory to practice.The research of this thesis has practical significance to further improve the effectiveness of globoidal cam transmission mechanism. |
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