The Initial Situation
As in many quarries, the first step in processing the extracted rock is crushing. In this case, the crusher is equipped with a 110-kW motor that connects to the drive via 8 SPC 7500 V-belts. The motor was mounted on a conventional sliding mount that establishes a fixed connection between the pulleys. Since the quarry has a high workload, the crusher suffered from frequent production downtime due to belt breaks or maintenance work. The high impact and enormous load took their toll on the belts and motor bearings. Each maintenance intervention was time-consuming and required three employees to carry out the work. As a result, the quarry suffered from reduced productivity.
The Solution
After a thorough analysis, the customer decided to invest in a ROSTA MB motor base. A significant improvement was noted shortly after installation. Not only did the belts last four times longer, but regular retensioning was no longer necessary. The frequent unexpected production stoppages were no longer a threat to productivity. The ROSTA MB 70×800 compensates for the shock loads that occur with every new stone drop in the crusher, thereby preventing the belts from absorbing all these loads as they would in a rigid system. Furthermore, frequent retensioning and realignment of the pulleys are no longer necessary. Once an MB is aligned, it does not need to be realigned.
Products Used
The ROSTA element used is the MB 70×800. This unit is a self-tensioning motor base for belt drives. It compensates for belt elongation, resulting in increased drive efficiency and the prevention of downtime. Furthermore, it eliminates the need for retensioning, dampens load peaks, and extends the service life of all drive components.