The engines and gearboxes of helicopters Mi-8 and MH-24 of various modifications applied synthetic oil B-SG TU 38101295-85. Until recently, the process of changing its operation was carried out at least once a year regardless of the developments I have the oil. This significantly limits its service life, resulting in significant operating costs.
In order to assess the eligibility deadline previously set oil change B-SG in two climatic zovah exploited 5 Mi-8 Mi-24 N, without holding an annual oil change. To monitor the status of the B-oil lubrication systems of pollutants from the engine and gearbox on a quarterly basis to take samples n investigated their physical, chemical and performance properties. As a result, studies have found that the oil-B pollutants, worked in the motor and gear of Mi-8 and Mi-24, 320- 470 hours, does not undergo significant changes. It saves a substantial margin performance, which makes its further exploitation.
In the study of the technical state of operating the engine and gearbox helicopters MH-8 and Mi-24 Air Force aircraft repair enterprises revealed that after the establishment of increased th life is almost the same as the technical condition of the engines and gearboxes used with an annual oil change. Therefore allowed to extend up to 2 years service life of oil B-pollutant engines and gearboxes of helicopters Mi-8, Mi-8Mt and MH-24. Fixed shelf life of oil-B pollutants in the container head an ode to the manufacturer (in sealed cans) of 10 years.
Synthetic oil LZ-240 TU 38401579-86 made on the same basis that I B-oil pollutants, — pentaerythritol esters, with the introduction of the antioxidant tion, anti-wear and anti-corrosion additives. By changing the composition of additives enhanced thermal stability of oil LZ-240 and eliminate the main drawback of the B-oil pollutants — the tendency to form sludge.
Oil LZ-240 can be used in engines and gearboxes of helicopters, which use oil B-SG. High thermal stability provides reliable long-term operation of engines and gearboxes of helicopters without oil change. In connection with this oil LZ-240 is approved for use on all types of helicopters entire life of the engine and the main gear without replacement. Since it is compatible with the B-oil pollutants, their replacement is done without flushing oil system. This limited drain oil change from a warm engine. Fixed shelf life of oil LZ-240 in the packaging factory 5 years.
Synthetic oil VNII NP 50-1-4U TU 3801590-86 widely used in jet engines. It is made on the basis of isooctyl acid sebatsiiovoy — dioctyl sebacate with antioxidant and anti-wear additives. The efficiency of the turbojet engine is provided with the engine oil temperature to 175 * C. Instead, oil VNII NP 50-1-4f developed oil VNII NP 50-1 -4u (improved). It has a higher temperature limit of efficiency (from 175 to 200 ° C) and longer life.
Both oils are produced on the same basis — dioctyl sebacate. Unlike oil VNII NP 50-1-4f, new additionally contains antioxidant and anticorrosive additives. Due to the introduction of a new formulation of additives enhanced thermal stability, which n provides higher performance properties of the oil VNII NP 50-1-4U. It is approved for use on the entire aviation technology instead of oil VNII NP 50-1 -4f na whole life without replacement, as well as products ’15B’ on a par with oil IPM-10. Oil VNII NP 50-1-4U in VNII NP 50-1-4f compatible, so their replacement is done without flushing oil system, limited to the drain / replaceable oil from the warm engine. Shelf life oil VNII NP 50-1-4f in the packaging factory 5 years.
Skilled engineering and aviation service should be remembered that modern lubricants for gas turbine engines are complex multicomponent systems containing up to 5—7 based additives.
The ability of such systems, or mixtures thereof maintain uniformly throughout the composition and properties are characterized compatibility. The practical importance of the compatibility of various oils acquires the replacement of oil by another operation and conservation (reactivation) technology, where possible mixing oil residues replaced with the newly refueled.
Currently, in accordance with existing requirements for each type of gas turbine engines are appointed by the prime and backup brand oils. In this regard, during the operation it becomes necessary to switch from one brand to another oil. This engine 8 is undrainable residual oil, which is mixed with the newly refueled. To eliminate this confusion before the envisaged two or three times washing of the engine oil system was replaced with fresh oil, which led to a substantial consumption of expensive high-quality oils.
With a view to economical and rational use of tested compatibility and properties of mixtures of various aviation oils and ordered an appropriate system to replace them. Since the recommended operational documentation flushing oil system oil change can be canceled only on the condition that both brands of oil compatible, they are mixed in any ratio, and their mixtures are able to maintain the physical uniformity of the entire volume, not delaminate and highlight of sediment during prolonged storage and application . A physico-chemical and performance properties of mixtures of these oils are similar to the properties of either component of the mixture.
Studies have shown that all the oil for operating groups are compatible with each other, except for the VT-301 oil with oil IPM-10 and PTS-225. They are not compatible, so the replacement must be made a double flushing oil system oil change. Established at the same time that the physico-chemical parameters and performance properties of mixtures of oils does not exceed the «higher» and not lower than the lower value indicators oils, oil-mixture components.