Analysis of failures of bearings of axle box unit with polyamide cages and prospects of increasing their service life

The article analyzes failures of bearings of the axle box unit with polyamide cages and investigates the influence of climatic conditions on operational characteristics of cages. It is determined that the greatest number of defects during the operation of polyamide cages occurs in the following periods: summer-autumn, autumn, winter, winter-spring, spring. The revealed dependence of the operational properties of polyamide samples on weather and climatic conditions in different seasons of the year allows predicting the change in the operational characteristics of the cage and taking measures to restore and improve them. The authors proposed a method of restoration and improvement of operational properties of cages by processing them using a technique of high-frequency electrothermy. Full-scale tests showed the high efficiency of the proposed method, expressed in reducing the weight of the samples as a result of moisture removal, as well as in an ambiguous change in strength properties. Their ambiguity lies in the fact that cages differently restore their original hardness indicators after processing. And in the periods corresponding to winter and winter-spring, it was possible to restore strength indicators to a level even above the original one. For high-frequency processing of polyamide cages, a device has been developed that provides the required coverage of the workpiece electrodes on the upper, lower and inner side surfaces of the partitions. The test of the developed device made is possible to achieve the desired results, expressed in a significant decrease in the relative humidity of the cages and an increase in their strength characteristics by 7.6% of the initial level. All this confirms the practical importance and progressiveness of the developments presented in the work.