Дослідження впливу рідкокристалічної присадки на трібологічні властивості гідравлічних олив для будівельних та колійних машин

Abstract

UA: У статті описано результати досліджень впливу рідкокристалічної присадки холестеринового типу на трібологічні властивості гідравлічних олив Mobil Hydraulic 10W та John Deere Hy-Gard. Обидві оливи виготовлені на мінеральній основі та містять заводські пакети присадок і є типовими гідравлічними оливами, аналоги яких застосовуються в гідравлічних приводах сучасної будівельної техніки, колійних та сільськогосподарських машин. Лабораторні дослідження показали покращення протизносних та протизадирних властивостей олив.

EN: The top priority of the modern tribology is to reduce equipment wear. Mechanisms and units of construction and track machines have a lot of friction pairs and the easiest way to reduce their wear and increase life is to use lubricants. Hydraulic equipment elements are no exception, as hydraulic oils are not only the working fluid of the system, they also lubricate the friction pairs of hydraulic units. So it is very important that they have an effective lubricity. Pure hydraulic oils have quite low performance properties. To improve them, special substances – additives – are added to lubricants. A large number of relevant compounds have already been studied. A promising trend in this area is the use of substances that are able to form liquid crystalline phases. It is the substances, which can form cholesterol boundary films on friction surfaces that draw our attention. Based on the relevant works, we selected a liquid crystalline substance with a phenanthrene skeleton of the cholesterol type and conducted a number of experimental studies. This additive was added to industrial oil. Laboratory studies have confirmed its effectiveness. This research continues to study the effect of liquid crystalline substance with phenanthrene on the tribological properties of oils used in construction and track machines. As the test oil we chose Mobil Hydraulic 10W and John Deere Hy-Gard, working fluids widely used in hydraulic drives in construction machines, track machines and agricultural machinery. Both are mineral-based and already contain additives. Like in our previous studies we used ultrasound to better dissolve the additive in the oil. The additive dissolved completely. The substance was added to the oil in various concentrations. Laboratory studies of tribological properties of hydraulic fluids were performed on a four-ball friction machine in accordance with the standard method described in GOST 9490-75 (USSR National standard). The main indicators of lubricity were determined – wear spot diameter, burr index, critical load and welding load. The results of the experiment showed the improvement of anti-wear and anti-seize properties of the studied hydraulic oils. Within the specified concentration range, the greatest anti-wear effect can be observed, which indicates the value of the rational concentration of the liquid crystal additive in hydraulic oils. The effect of the additive in the area of maximum loads is not significant.