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

Ключевые слова: тепловой контроль, токарно-винторезный станок, шпиндельный узел, подшипники качения, энергоэффективные технологии, определяющий параметр, скорость нагрева.

Наталія Перетяка, к.т.н. (старший викладач кафедри метрології та метрологічного забезпечення Одеської державної академії технічного регулювання та якості) Костянтин Боряк, д.т.н. (завідувач кафедри метрології та метрологічного забезпечення Одеської державної академії технічного регулювання та якості) АНАЛІЗ ВИПРОБУВАЛЬНИХ СТЕНДІВ МЕХАНІЧНИХ РЕДУКТОРІВ Стаття присвячена аналізу конструкцій та технічних характеристик випробувальних стендів для випробувань механічних редукторів. Виявлені технічні недоліки існуючих стендів та зазначені основні напрями вдосконалення існуючого обладнання, зокрема, вдосконалення конструкції електроприводу стенда та автоматизація процесу випробування, що дає змогу підвищити якість стендових випробувань механічних редукторів.

The automatic regulator РКЗТ-675 (РТПР-675) and РТПР-675M is installed in the brake lever transmission of the passenger car and used for automatical maintenance of gaps between the surfaces of rolling of wheel pairs and brake pads within the established limits irrespective of the wear of the rolling surfaces of wheels. The design of auto regulators allows you to change the stroke of the piston rod and the brake cylinder and to manually release and tighten the regulator. Scope of auto regulators: freight, passenger cars and electric trains of the main railways. The article is devoted to solving the problem of contradictions in clause 15.5.7 of the current departmental Ukrainian instruction ЦЛ-0013 for repairing brake equipment of the railway carriage of the existing requirement for mandatory compliance with screw unscrewing in size "a" within 300-350 mm when testing automatic regulators on an automatic test stand for strength under load a normalized force of 8t in the longitudinal direction, provided that there are no residual deformations of the automatic regulator screw along its length. The article aims to refute the dependence of the values of the stress state of an automatic regulator when testing its strength on a test bench from a change in its length in the entire possible range of screw unscrewing by size "a" in the allowable range of 0-600 mm. The problem is solved by calculation using two different methods, and the results of the stress state values of the automatic regulator with different lengths of screw unscrewing by size “a” are compared with each other. Based on this, the general conclusion is made that the size “a” (within the range of 0–600 mm) of the automatic regulator screw unscrewing when testing it for strength with the same load force (N = 8t ≈ 80 кН) in the longitudinal direction does not affect the calculated value of the screw tension σ = 113.23 MPa when tested on an automatic bench. The developers of the departmental Ukrainian instruction ЦЛ-0013 are invited to make in clause 15.5.7 corresponding changes regarding the requirement of optional observance of the value of the size "a" within 300-350 mm at the bench test of the automatic regulators for the tensile load under the standardized force of 8t.