Research On A New Type Of Lever Reducer

The robot industry has been applied to all aspects of military and people’s livelihood such as logistics and transportation,manned spaceflight,manufacturing and medical equipment.Industrial robots consist of mechanical components(reducers,etc.)and electrical components(servo motors,drives,sensors,controllers,etc.).Precision reducer is one of the key technologies of robot research.The reducer for robots requires high load capacity,large transmission ratio,high efficiency and smooth transmission.Precision reducers can be divided into five categories according to their functions and transmission modes:RV reducer,harmonic reducer,planetary gear reducer,cycloidal pin reducer and filter reducer.A new type of lever type reducer with three-stage reduction transmission is the research object of this thesis.They are fixed axle train transmission,lever transmission based on spherical motion pair and internal translation gear transmission.In this thesis,the principle analysis,transmission parameter design,virtual prototype modeling,motion simulation,finite element analysis and lever structure optimization were carried out for the reducer.On this basis,the merits and inadequacies of the lever type reducer were analyzed in this paper,and a new type of nutation gear reducer as an improvement was proposed to improve the research of the gear reducer with less tooth difference.Firstly,the three-stage reduction transmission from the principle was analyzed in this paper,the degree of freedom of the lever transmission mechanism was calculated,and the transmission ratio of the internal translation gear transmission was calculated.In the paper,the calculation and distribution of the gear ratio of the reducer were completed,and the parameter design of the gear transmission was completed according to the performance requirements of the tooth surface contact fatigue strength limitation and the root bending fatigue strength limitation.In the paper,the gearless internal gear was modified to meet the gear meshing requirements.The virtual prototype modeling of the reducer was completed based on the structural improvement of the reducer.Kinematics simulations were performed with SolidWorks’ Motion module.Finite element analysis of key mechanisms were performed with SolidWorks’ Simulation module.The rationality of the design of the reducer was verified from the principles of kinematics and statics,and the results were analyzed to determine the weakness of the structure of the reducer as the mechanism to be optimized.Then the structural optimization of the lever transmission mechanism based on genetic algorithm was completed in this paper,the basic principles and processes of genetic algorithms were introduced,the model of the lever transmission was simplified,input variables and their range of values were selected,the target performance parameters was selected on the base of simulation and analysis results and the fitness function was determined,initialization group,coding,fitness calculation,roulette,selective copy cross variation and decoding output were completed,genetic algorithm simulation was completed in MATLAB,the simulation results were analyzed and the final values were determined based on geometric constraints and machining assembly constraints.Finally,the merits and inadequacies of the lever type reducer were analyzed in this paper.Based on those,a nutation reducer was proposed to make up for its shortcomings.The principle of nutation gear transmission was analyzed,and the design of small tooth difference and zero tooth difference transmission and cross connection mechanism was completed.The 3D printing was completed in this paper.The merits and inadequacies of the lever type reducer and the nutation gear reducer were analyzed and compared.