Науковий підхід до вибору і розрахунку посадок у машинобудуванні

Abstract

Проведені експериментальні та наукові дослідження з розрахунку та впровадження різноманітних посадок у гладких з’єднаннях у навчальний процес та виробництво. Математично обґрунтовано необхідність застосування посадок із зазором, перехідних та з натягом у кожному окремому випадку. Проведено та розроблено рекомендації з вибору квалітетів точності на час інженерних розрахунків у машинобудуванні.

Experimental and scientific researches of calculation and implementation of various fits in smooth connections in educational and production processes were conducted. The necessity of the use of fits with clearance, transitional and with tension in each individual case was mathematically grounded. Recommendations of accuracy workmanships choosing during engineering calculations in mechanical engineering were analyzed and elaborated. In the first place it is necessary to choose the type of fit (with tension, transition or with clearance) which depends on the functions of a particular assembly and the reciprocal position of parts during their operation. After the type of fit choosing it is necessary to define limiting declinations of clearance values Smin and Smax or tension values Nmin and Nmax and at the same time workmanship accuracies of connecting parts. Design is common method for determining of fits, black belts and production accuracy, it is similar to use of previous years mechanical engineering experience. It should be known: the materials from which the parts are made; types and nature of oils are used during the operation; surfaces roughness, which can be achieved in production process; accuracy of machine tools for parts production; lifetime to repair work; accuracy of finished mechanism work. How are the fits chosen? Various fits for moving and fixed connections are chosen on the base of previous scientific calculations, experimental studies and with taking into account of similar well known connections. The calculations of the choice of moving fits, such as bearings, are done on the base of hydraulic friction theory and based on the defining of the necessary clearance for fluid friction providing. In other cases, the clearances can be calculated in terms of shapes deflection compensation and surfaces position for providing easy assembly of parts.