1. Srđan Bošnjak, Faculty of Mechanical Engeneering, Belgrade, Serbia
2. Milos Djordjevic, FME Belegrade, Serbia
3. Nebojša Gnjatović, Faculty of Mechanical Engeneering, Belgrade, Serbia
4. Nenad Zrnic, FME Belegrade, Serbia
In the general case, there are three basic reasons for the bucket wheel excavators subsystems redesign: (1) better customization of the machine versus operating conditions; (2) easier maintenance; (3) failure of the considered substructure. Improved design solutions, wich are exposed in this paper, were developed to satisfy the first and second reason. Namely, obsolete conception and constant perrenial exploitation in heavy duty conditions made it necessary to redesign the excavating device of the bucket wheel excavator SchRs 350. Some characteristic problems which occur during exploitation and maintenance are discussed/listed. Paper presents a redesign concept which includes substitution of the existig spur - geared bucket wheel gearbox with a planetary one and the redesign of the BW body and its connection with the output gearbox shaft. It also shows the results of the comparative load analysis for the original and the redesigned bucket wheel body. Protection of the original bucket wheel drive of the excavator SchRs 1760 was realised by magnetic powder clutches. Because of the relatively high price and problems noticed during exploitation (overheating resulting in fusing of the powder) the solution design of the bucket wheel drive with fluid couplings is developed. Thanks to the mentioned redesign, a partial revitalizations of the bucket wheel excavators are realised, which leads to a considerable increase of machines reliability as well as the reliability of the complete surface mining system, and additionally makes the maintenance process easier.
Mehanika i konstrukcije