MODEL FOR CALCULATING THE RELIABILITY OF SAMPLES OF KINEMATIK PAIRS OF MACHINE-ROBOTS

Abstract

In the article, the reliability issues of machine tool mechanisms are still more at the stages of pre-project studies and experimental tests. In connection with the introduction of highly effective technological processes, systems of automated design and production, complex systems that provide a high level of labor productivity, the requirements for reliability, durability and workability are constantly growing. Failures of mechanisms in the composition of robotic machines, in accordance with their physical nature, can be associated with the destruction of nodes and details of mechanisms and their drives, jamming of individual elements and other reasons that lead to the fact that the technological equipment becomes unable to perform its functions. Rice's formula was used to determine the average parameter of the flow of rejections. To estimate the average parameter of the flow of failures, it is necessary to know the density of the joint distribution of the state parameter and the rate of its change over time. In many cases, such processes are described by a stationary random function with a normal law of distribution of both the state parameter and the rate of its change. Parametric failures precede functional failures, and can also cause them. Sudden failures are considered in a quasi-static formulation as the process of a random sequence of parameters exceeding the permissible limits in space. It is proposed to carry out the reliability study in the following three main stages: construction on the basis of theoretical or experimental studies of the dependence of the initial parameter on load indicators; thorough statistical analysis of operating conditions, probabilistic description of load indicators; construction of the distribution of the initial parameter. The algorithm for calculating system reliability indicators is presented, the initial parameter of which is presented in the form of a random sequence, imitating the work of a certain number of samples of the machine-work kinematic pair in real operational conditions up to their complete wear. The initial basic size and criterion parameter for each sample are determined by the Monte Carlo method.