Research On Assembly Precision Of RV Reducer Based On Probability Theory

RV reducer is a new type of precision transmission mechanism,with a series of advantages such as high transmission accuracy,high torque,impact resistance,etc.it is the core part of industrial robot,and its deviation transfer mechanism,transmission accuracy and other performance has been the focus of research in the field of industrial robot.In order to study the influence of deviation transfer in RV gear reducer on assembly accuracy,this paper analyzes the deviation source that affects assembly accuracy and the deviation transfer mechanism from the perspective of assembly,simulates the deviation transfer mechanism in the assembly process of the whole machine,and finds out the main factors that affect the transmission accuracy of the whole machine.The main research contents of this paper are as follows:1.Taking RV-40 E reducer as an example,this paper analyzes the meshing relationship of each part of the transmission system and its working principle,introduces the functional characteristics of its main parts,and successfully deduces the transmission ratio formula of the reducer when fixing its shell.2.Combined with the characteristics of the transmission structure of RV reducer,analyze the sources of three types of deviation sources that affect the assembly deviation of the whole machine in parts,and classify them.Combined with the loop method to analyze the positive and negative accumulation mechanism of three kinds of deviation sources in parts,a unified multivariate statistical mathematical model of RV-40 E gear reducer deviation transfer was established based on probability theory and vector method.3.Based on the unified multivariate statistical mathematical model of RV-40 E gear reducer deviation transfer,the mating type and state of the parts on the assembly mating surface were studied and the mating relation table was developed.Based on the deviation transfer analysis,four basic deviation flow models are proposed,and the deviation directed graph model of the whole machine is established by taking the RV-40 E reducer as the research example.4.Monte Carlo algorithm is used to derive the formula of the assembly deviation statistics of RV-40 E reducer stage 1 system,stage 2 system and the whole machine.Then the assembly precision of the whole machine and the contribution degree of each system are solved.It is concluded that the second stage cycloidal pin gear transmission system has the greatest influence on the assembly precision of the whole machine.Based on the factorial method,the main sourceof deviation affecting the assembly accuracy was found to be the geometric position deviation.