Concerns over the prices of new medicines have been growing over the past decade. In the US, estimated net prices of newly launched prescription drugs increased from a median of around $1400 a year (£1200; €1300) in 2008 to over $150 000 a year in 2021. 1 Onasemnogene abeparvovec (Zolgensma), a gene therapy approved by the US Food and Drug Administration in 2019 for spinal muscular atrophy, was at the time of approval the most expensive drug ever, with a price of over $2m for a single dose treatment. 2 Several more recent drugs for rare diseases are priced even higher, 3 with a gene therapy for haemophilia B approved by the FDA in November 2022 costing $3.5m per dose. 4 But even old and common drugs have seen inexplicable price increases: in the US, the list price of some insulin products increased more than twofold from 2007 to 2018, 5 while a US government report identified 1216 products that had seen prices rise above inflation

Reliability of rotating machinery is determined to a considerable degree by the bearing units. For several applications the requirements in rotation speed, bearing load and maximal vibration level are so extreme that neither rolling-element bearings nor fluid-film bearings could provide necessary performance characteristics during all regimes of operation. Hybrid bearings, which are a combination of rolling-element and fluid-film bearings, can improve performance characteristics and reliability of the rotor-bearing systems. The aim of this work is to analyze the advantages and disadvantages of the hybrid bearings. Known real applications of hybrid bearings are discussed. Analysis shows that depending on the application different hybrid bearing types could improve dynamic characteristics and life time of the bearing unit, increase load capacity and DN limit of the rolling-element bearing.

The article presents the design and operation principle of a hybrid bearing with actively adjustable radial gap of a gas foil bearing. The hybrid bearing is a combination of a ball bearing and gas foil bearing with speed separation. Electromagnetic coils are placed on the bearing housing, two for each foil. Such a construction allows to control the deformation of the foils by applying voltage to the coils. The article also presents a general approach to mathematical model the control process in such bearings. The main purpose of the control system is to reduce vibrations in the rotor system by means of controlling dynamic characteristics of the gas foil bearing.

Reliability of rotating machinery is determined to a considerable degree by the bearing units. For several applications the requirements in rotational speed, bearing load and maximal vibration level are so extreme that neither rolling-element bearings nor fluid-film bearings could provide necessary operating characteristics during all regimes of operation. Hybrid bearings, which are a combination of rolling-element and fluid-film bearings, can improve performance characteristics and reliability of the rotor-bearing systems. A hybrid bearing, where a rolling-element bearing and a fluid-film bearing are positioned parallel to the vector of external load (PLEX), has the following advantages compared to a single bearing, whether rolling-element or fluid-film one: increase of life expectancy, load capacity increase, friction reduction, thermal regime enhancement, increase of stiffness, and damping properties. The present paper presents the results of theoretical and numerical research of friction characteristics of PLEX in mixed sliding and rolling friction, i.e. combination of viscous and rolling contact friction, regime. The conditions of minimum friction effect occurrence have been substantiated, and rational relations between characteristics of hybrid rolling-element bearings and fluid-film bearings needed for provision of such effect have been experimentally proven. Finally, the paper presents recommendations regarding design of such hybrid bearings for heavily loaded bearing nodes of rolling mills.

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Failure diagnostics and general decrease of accident rate at power plants is a major task of energy generation industry, and solution of it provides reliable energy supply country wide and technological progress in mechanical engineering. Along with some other crucial means, the task could be solved by means of teaching the maintenance staff based on accidents that have already occurred. That is no secret that everywhere in the world due to indecision or misinterpretation a huge number of accidents have happened merely because the personnel were not aware of similar cases at other power plants. Nevertheless with the development of computational technologies and mathematical algorithms the role of personnel in some cases has been reduced to observation and action in critical situation, while the rest is performed by machines: various types of diagnostics and prediction of failure systems based on artificial neural networks are widely applied and developed. However, in order to train these systems, it is absolutely required to know the reasons that could lead to and consequences that could follow some deterioration in turbo generator sets performance. The aim of the present paper is to give statistical analysis of turbo generator sets failure reasons based on open source data presented by Russian and foreign researchers and analysts in the field. The statistical data could be used to perform classification and ranking of failure reasons in terms of frequency of occurrence, possibility to identify or detect, etc. and the paper also gives brief listing of possible ways of detection or identification of failure modes and possible consequences for the main units of a turbo generator.

The present paper considers a multi-criteria analysis algorithm of turbo generator fluidfilm bearing operability and its connection with rotor machine monitoring system data. It is substantiated that implementation of predictive analysis of load capacity, locus curves and dynamic displacements allows prognosis of useful life of a fluid-film bearings and improvement of reliability of a rotor machine.

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