Methods of preparation of the experiment for investigation of universal joints on needle bearings

The main directions of development and improvement of performance data of universal joints needle bearings of transport technological machines are considered. The questions and tasks requiring the solution at the level of forming of new calculation procedures are specified. Modern achievements in researches of endurance failures and low-cyclic fatigue of needle bearings are considered. The main overview of the works performed in this direction is provided. The analysis of modern ideas of fatigue processes of needle bearings is given. The analysis of the current state of question on research of plastic deformation at static contact loading of needle bearings is given. Questions of forecasting of durability of needle bearings of universal joints are considered. The main questions connected with processes of forming of fatigue cracks in materials of needle bearings of universal joints in zones of power contact are considered. On the basis of the analysis of the used sources it was revealed that it is necessary to resolve the issues connected with improvement of performance data of universal joints needle bearings and questions of calculation of bearing capacity of power contact of rolling bearings and technology of receiving qualitative materials. For carrying out tests we used the test facility for universal joints allowing tests without overheat of system of braking due to cooling of working fluid and also improving operating conditions due to ensuring smoothness of regulation of braking torque. For measurement of roughness of surfaces the USB BV-7669M Profilograph profilometer was used. For measurement of hardness of surfaces of thorns of crosspiece of universal joints the HBRV-187,5 hardness gage was used. The technique of carrying out tests includes the following stages: marking of crosspieces of universal joints; measurement of roughness, hardness, geometry of crosspieces of universal joints; stage of tests; repeated measurements of roughness, hardness and geometry of crosspieces of universal joints; cutting of the studied universal joints and production of microsections for metallographic examinatons of active and passive surfaces of thorns of crosspieces of universal joints; processing of results of researches. The given technique of planning of experiments is intended for receiving experimental data of researches of universal joints at different stages of operation that will allow to estimate influences of errors of production on performance data of universal joints and to prove the reasons of formation of face and deep cracks.