Improving the thermal method for assessing the technical condition of rolling bearings based on the heating rate criterion

Abstract

An improved method of passive thermal control has been proposed in order to operatively assess the technical condition of rolling bearings, based on studying the heating rate of a bearing. The values of the heating rate of ball, roller, and conical rolling bearings, as well as ball separators, have been determined empirically. It has been shown that the discrete limit heating rate values derived under the regular heating mode of mechanical reducers during stand tests are suitable for use as a diagnostic criterion for rolling bearings. Based on the heating speed criterion for mechanical reducers, it is possible to perform an operative assessment of the technical condition of rolling bearings of different types during the operation of equipment for different purposes. It has been established that for a rolling bearing in a working technical condition the heating rate under a regular heating mode does not exceed 1 °C/min. The resulting value corresponds to the diagnostic criterion for the heating rate of mechanical reducers in a working technical condition of ϑ n ≤1.1 °C/min. Using a diagnostic parameter of the heating rate under a regular heating mode makes it possible to resolve the issue related to the duration of control over the technical condition of a rolling bearing using a thermal method. Reducing the control procedure duration, when using the improved thermal non-destructive testing, by 4 times, would yield a reduction in operating costs due to the possibility of ongoing control over rolling bearings at the beginning of the equipment operation. It has also been confirmed that the heating rate of rolling bearings under a regular heating mode directly depends on their technical condition and does not depend on the load transferred and the mode of operation of the bearing nodes of the technological equipment. The proposed method could be applied in the maintenance system based on the actual condition of the equipment for the operative control over rolling bearings

Effects of Oil and Solid Body Temperatures on Elastohydrodynamic Lubrication Film Formation

“…The generated heat propagates through the bearings, inducing alterations in the temperature field, thereby exerting an influence on the overall performance of rolling bearings [1], the limiting speed [2], and even their service life [3]. Therefore, the measurement of temperature rise has been widely adopted as an important parameter in bearing tests for evaluating lubrication properties [4,5] and serves as a failure criterion for lubricants or rolling bearings [6,7].…”

Temperature Conditions and Diagnostics of Bearings

“…Thermal diagnostics accuracy of bearing assemblies is affected by heating factors from ambient air, adjacent heat sources and solar radiation [9]. Therefore, diagnostics by the temperature measured on the outer surface of the bearing assembly has no practical application [10][11][12][13][14][15]. Modern technologies and technical means of temperature measurement make it possible to perform thermal diagnostics automatically, without manual labour, but only when measuring the temperature of the outer surface of the bearing assembly [16][17][18][19].…”