THE INITIAL SITUATION
As in many quarries, a first step in processing mined rocks is crushing them. In this case the crusher is equipped with 110 kW motor connecting the drive with 8 SPC 7500 V-belts. The motor was mounted on traditional sliding setup creating a fixed connection between the pulleys. Since the quarry has a high work load the crusher uffered from frequent production standstill due to broken belts or maintenance work. The high impact and the huge load took its toll on the belts and motor bearings. Any maintenance intervention was time consuming and required three staff to execute the work. Subsequently the quarry suffered from reduced productivity.
After a thorough analysis the client decided to invest in a ROSTA motor base MB. Short after the installation a significant improvement was noticed. Not only lasted the belts four times longer but also the regular re-tensioning was not required anymore. The frequent unexpected production stops where no longer a threat to the productivity. The ROSTA MB 70×800 compensates shock loads which occur with every new rock dropped in the crusher and therefore prevents the belts form taking up all these loads like they do in a rigid installation. Additionally, the frequent re-tensioning and the realignment of the pulleys are no longer need. Once an MB is aligned there is no need for re alignment.
The used ROSTA element is MB 70×800. This unit is a self and automatic tensioning motorbase for belt drives. It
offers compensation of belt elongations which results to increased drive efficiency and eliminating downtime. Furthermore no re-alignment is needed, dampens peak- loads and offers longer service life of all drive components.