International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The basic method for examining the condition of gears is the vibroacoustic method. This method is widely used around the world for diagnostic purposes. However, it is not always possible to use it. This especially applies to mechanisms operating ultimately in space. Harsh working conditions, the presence of the vacuum of space, radiation, reactive oxygen ions and many other factors make diagnostics in this environment much more difficult. This article compares vibroacoustic, electrical, optical and other methods in terms of their potential application for diagnostic purposes of gears used in the space industry.

Vegetable oils are mixtures of mainly triglycerides of fatty acids. Their particles are large and have significantly different shapes. This causes problems in matching the molecules to each other and their translation and rotation necessary for the phase transition to occur. All this causes that phase transformations in vegetable oils have a long-time character. This article presents a comparison of the times of occurrence of this type of pressure-induced transformations for olive, sunflower, rapeseed and other oils. Possible causes of differences between them were also analyzed. The analysis of the phenomena occurring during phase transformations is crucial because during them the mechanical and electrical properties of oils change rapidly.

Research on vegetable oils was already carried out in the industrial era. Oils are used not only in the food industry, but also in the cosmetics and pharmaceutical industries. Due to the beneficial effect on the human body, they have been studied more and more thoroughly. The development of high pressure food preservation has further accelerated this process. Due to the use of pressure in the production and preservation of food, it turned out to be important to study the phase transitions induced by pressure in these oils. Due to their long-term nature, these transformations may damage the machines used in the industry. So far well-researched vegetable oils in this regard are castor oil, rapeseed oil, soybean oil, sunflower oil and olive oil. Research on other oils will be conducted in the future.