Extreme powerful gear drives have a relatively elastic structure of housing components. The supports and the connections with the carrying structure are not rigid enough either, including this structure itself. The paper analyses the gear unit supporting bearings failure of bucket wheel excavators. The failure of BWE SchRs-1600 occured after a very short service life, in the form of progresive and catastrophic pitting. The presented analysis shows that this phenomenon appeared due to multiple synchronized influences which are a direct consequence of the structure elasticity, the reducer and output shaft masses eccentricity, the moment lever rigidity, and the bearing area local deformations. An improved design solution as well as the mentioned analyses are presented. Additionally, gear transmission units can operate properly in the resonance conditions but they cause very unfavorable effects on other components, such as the bearings. The article contains gear resonance identification and its influence on rapid failure of bearings and other gears of the SRs-1301 bucket wheel excavator. Thereafter follows the correction of design parameters of the critical gear pair in order to avoid its resonance and excitation of natural frequencies of gearbox housing.Original Abstract: Zupcasti prijenosnici velikih snaga imaju relativno elasticna kucista. Takoder oslonci i veze s nosivom konstrukcijom nisu dovoljno krute, ukljucujuci i samu strukturu prijenosnika. Clanak sadrzi analizu razaranja lezaja reduktora rotornih bagera. Kod rotomog bagera SchRs-1600, kvar se dogodio nakon vrlo kratkog rada u formi progresivnog i vrlo razarajuce rupicavosti (pitinga). Prikazana analiza ukazuje na to da se ovaj fenomen pojavio zbog visestrukih sinhroniziranih utjecaja koji su direktna posljedica elasticnosti strukture, ekscentricnosti reduktora i masa izlaznog vratila, krutosti momentne poluge i lokalnih deformacija u okolini lezaja. Poboljsano konstrukcijsko rjesenje skupa sa spomenutim analizama prikazani su u radu. Osim toga, zupcanici u zupcastim prijenosnicima mogu ispravno raditi u uvjetima rezonancije, ali oni izazivaju vrlo nepovoljne uvjete za rad drugih komponenata kao sto su lezaji. Clanak sadrzi identifikaciju rezonancije zupcanika kao i analizu njihovog utjecaja na ostecenja lezaja i drugih zupcanika, koja nastupaju vrlo brzo, kod rotornog bagera SRs-1301. Iza toga slijedi prikaz uskladivanja parametara konstrukcijskog rjesenja kriticnog zupcastog para kako bi se izbjegla njegova rezonancija i pobuda vlastitih frekvencija kucista.