Authors present the general characteristics of the gas-dynamic foil bearings in the paper. The short analysis of the application and possibilities of using gas-dynamic bearings in turbo machinery, especially in the aspect of aviation technology were described. Authors also pointed out possible directions of development and gas-dynamic foil bearings application in high-speed turbines, especially working in high temperature.

This paper presents problems of oil film thickness measurements, especially during tribological experiments. There are many methods of oil layer measurement. More of them is used in measurement apparatus. Most popular method to oil film thickness is electric method. Authors indicate that triboelectrical phenomenon disrupts the real value of resistance because of charge particles which change conductance of the oil layer.

Traces of mechanical wear appear on co-working surfaces in the operation of precision fluid bearings. This should not be the case, since fluid friction and uninterrupted oil film should be present in a friction pair, which is a concept that this paper attempts to outline. The way friction forces, resistance, and oil film vary as unit pressure rises linearly is discussed. Three stages of the variations are distinguished. At the first stage, the oil film thickness and force of friction remain steady while the resistance declines. Stage two is temporary: Triboelectrical phenomena already escalate considerably and begin to decide effects of the friction process while a lubricant loses rheological properties of the Newtonian fluid. Hydrodynamic friction continues at the third stage, yet the triboelectrical effects are decided by stabilised triboelectrical phenomena. The third range can be identified as boundary friction where the layer separating surfaces is thicker than in the area of Newtonian rheology. This is very good in respect to wear, but higher-energy (not electrically neutral) particles cause increases in friction resistances. This range seems to exhibit a very high potential for being controlled with an adequate selection of oil based additions.

The article presents the risk assesment of damages occurance in production stage of a babycarriage with a bike function. The analysis of risk is done by using the FMEA – Failure Made and Effect Analysis that is used in aviation and automotive industry. This way of innovative product assessment allows to evaluate the risk of defects and indicate the priorities of quality for key parts as well as the device.

This paper presents and discusses an experimental method of friction during the current flow in sliding zone with lubrication. There is also showed typical friction changes of several parameters depending on a load and DC voltage. It allows to observe positive and negative results of the friction. A low level of electrical energy used in friction zone can improve the work conditions. When power of the electric energy is exceeded it leads to the micro-welding, especially during the high load. On the other hand we notice a new possibility of using electric current to friction force steering.