Research On Planetary Line Gear Reducer With Small Tooth Number Difference And CNC Manufacturing Method Of Line Gear And Development Of Machine Tool

Line gear is designed based on space conjugate curve meshing theory.The flexible design makes it have the characteristics of small duty cycle.The minimum number of teeth can be 1 and have no undercutting phenomenon.Besides,it can realize the transmission of parallel axes,two arbitrary angle axes on the same plane and on two skewed axes.As an innovative gear,line gear has prominent advantages which make it has broad application prospects.In previous studies,many progresses on line gear mainly focused on theory.As for practical application,it is deficient.Take industrialization as the ultimate goal,it designs a planetary reducer with small tooth number difference based on line gear pairs in this paper.And the milling method of line gear is studied.At the same time,a special CNC machine tool for line gear is developed.From the design to manufacture of the line gear reducer,it explores the way for the practical application of the line gear.The main contents of this paper include:1.A planetary reducer with small tooth number difference based on line gear is designed.According to the basic meshing theory of line gear,the design method of internal meshing line gear pair based on concave-convex arc profile is proposed for the first time.Based on the principle of planetary gear transmission with small tooth number difference and the design method of internal meshing line gear pair,a NN planetary gear reducer with small tooth number difference was developed.Every parts of reducer are complete designed and the reducer efficiency calculation is given.The contact strength of line gears are checked with the help of ANSYS Workbench software.The reducer has large transmission ratio and small volume,making full use of the advantages of line gear.It's suitable for small space and light load transmission occasions.2.A new method of forming milling specially for line gear processing is proposed.According to the generating characteristics of the tooth surface of line gear,based on the forming processing theory,the processing theory apply to the internal and external line gear with circular and elliptic arc profile is put forward,and the design method of different milling cutters is given for the processing of the internal and external line gear.According to the different selection of milling cutters and machine tools,the path of the cutter location in the process is solved.This method provides a powerful help for the mass production of line gear.3.The first generation of special CNC machine tools for line gear is developed.Based on the processing technology requirements of line gear,the required motion and motion allocation schemes for machine tools are determined.Considering the economy and operation performance of the machine tool,the special machine tool is developed by refitting a three-axis vertical CNC machine tool.Aiming at the special needs of line gear processing,the swing platform technology equipment was designed,and the mother machine tool and other components matching it were selected.Finally,the first generation special machine tool prototype was produced.The development of special CNC machine tools for line gear provides an important platform for the cutting of line gear.4.Using the first generation special CNC machine tool,the line gear pairs with cylindrical helix and conical helix as driving contact curve were tested respectively.After assembled,the reducers were tested on the Line Gear Dynamics Test-bed with their transmission performance.