Constructions of the mechanical-bearingless centrifugal blood pumps utilize different types of non-contact physical bearings, which allows to balance the forces that have an impact on the pump impeller, stabilizing its position in the pump house without wall contact. The paper presents investigations of the hybrid (passive magnetic bearings and hydrodynamic bearings) suspension system for the centrifugal blood pump. Numerical simulations were used to evaluate the hydrodynamic bearing lifting force and magnetic bearing forces interaction. An important aspect of rotor suspension system design was the nominal gap in hydrodynamic bearing area in order to reduce the blood damage risk in this region. The analyses results confirmed that for a small diameter centrifugal pump, the nominal operating hydrodynamic bearing gap could be established within the range from 0.033 to 0.072 mm.Keywords: titanium nitride layers, athrombogenic coatings, implantable rotary pump, heart assistance Konstrukcje pomp odśrodkowych pozbawionych łożysk mechanicznych wykorzystują różne rodzaje bezkontaktowych łożysk fizycznych, które pozwalają balansować siły oddziałujące na wirnik pompy, stabilizując jego pozycję w obudowie pompy bez kontaktu ze ścianami. Artykuł przedstawia badania hybrydowego (pasywne łożyska magnetyczne i łożyska hydrodynamiczne) systemu zawieszenia wirnika dla odśrodkowej pompy krwi. Symulacji numerycznych użyto dla zbadania siły unoszącej łożyska hydrodynamicznego oraz reakcji łożysk magnetycznych. Ważnym aspektem konstrukcji systemu zawieszenia wirnika było zwięk-szenie nominalnego prześwitu w obszarze łożyska hydrodynamicznego, aby zredukować ryzyko uszkadzania krwi w tym rejonie. Wyniki analiz potwierdziły możliwość wyznaczenia nominalnego prześwitu w łożysku hydrodynamicznym, dla pomp odśrodkowych małej średnicy, w przedziale od 0,033 do 0,072 mm.

This article presents the new construction of a centrifugal impeller pump which supplies the cooling system in coal power plants. The article also shows the history of producing this kind if pumps for unified power units of 125 MW and 200 MW which dominate in Poland. The process of numerical analysis and conventional calculations leading to the improvement of qualities of the flowing system exceeding literature indicators are presented. The article shows the problems which appeared during assembling the pump in its target workplace. The results of the measurements of the pump flowing system in its target workplace are presented.

This paper presents new construction of a submersible pump which is highly efficient due to the new solutions for flow channels. It includes the results of laboratory tests of the pump of the new construction. It also presents the results of numerical calculations of liquid’s movement in the flow channels of the pump, comparison of computing characteristics and characteristics measured in the laboratory.and an analysis of the essential parameters of the pump’s work which transgression could become a danger for the pump. In case of the danger the security system turns off the engine temporally or permanently.

Mathematical modeling of the complex process in the human cardiovascular system is powerful tool to evaluate the dynamic system response for the parameters change. Widely used continuous flow pumps (Left Ventricle Assist Device - LVAD) interacting with the circulatory system and work parameters of the assist device are changing dynamically. Different parameters of the system affect the pump operating conditions and on the contrary. Mathematical modeling of interaction between the cardiovascular system and mechanical assist device allows to identify the dangerous effects in the pump and system operation, and to eliminate such situations in the practical using of such pumps.