Failure analysis of rotary screw pump

Abstract

A case study of damage of a rotary high-pressure three screw oil hydraulic pump for regulator oil in hydroelectric power plant is presented. Results of chemical composition analysis, mechanical properties, impact energy testing and hardness measurement of power and idle rotor materials are presented and discussed. Casing inner surfaces and samples of power and idle rotor materials are examined by metallographic analyses. Obtained results allowed to conclude that life of rotary screw pumps may be extended by regular cleanness inspection of filter and its replacement if necessary, control of rolling bearings condition, oil viscosity and cleanness, and proper operation of valves and automatics.

U radu je prikazana analiza oštećenja rotacione vijčane pumpe visokog pritiska za hidraulično ulje u regulatoru u pogonu hidroelektrane. Izloženi su i diskutovani rezultati analize hemijskog sastava, ispitivanja mehaničkih osobina i energije udara i merenja tvrdoće materijala pogonskog i slobodnog vretena. Unutrašnje površine kućišta i uzorci materijala pogonskog i slobodnog vretena su ispitani metalografskom analizom. Na osnovu dobijenih rezultata je zaključeno da vek rotacionih zavojnih pumpi može biti produžen redovnom kontrolom čistoće prečistača i njihovom zamenom kada je to potrebno, kontrolom stanja kotrljajnih ležajeva, viskoznosti i čistoće ulja, i ispravnim radom ventila i automatike.