In a ceremony on January 23 at the Bucyrus facility in Lünen, Germany the company celebrated the completion of the 400th CST (Controlled Start Transmission) drive system since 1994. The “Jubilee System” is a gearbox of model size KP-CST 65 and will be delivered to one of its largest customers in the US together with two sister gearboxes. There it will be used on a Bucyrus face conveyor with a total installed power of 3 x 1.200 kW. Bucyrus was awarded the order for a face extension, equipping all 18 AFCs of this customer with two drive frames and three CST drive systems each; that means a total of 54 CST gearboxes. The complete program extends over several years. For the customer, the drive technology offered was the decisive factor for awarding the order to Bucyrus.
The first integrated drive system specifically developed for these types of face conveyors was the intelligent CST drive system. CST basically means tha this sytem provides a controlled soft start. It was developed in a joint venture with a Bucyrus underground segment predecessor company, Westfalia Lünen, and the US company Baldor Dodge Reliance. This joint venture was initiated in 1993, and was renewed again in 2008. The renewed 2008 agreement grants Bucyrus sustained exclusivity with respect to the use of this technology in the field of chain conveyors.
The drive system consists of a Bucyrus planetary gearbox with an integrated infinitely controlled Baldor Dodge Reliance CST multi-disc clutch which has a proven track record from numerous applications on belt systems. The highly sophisticated drive control system for the CST, the so-called PMC®-D control system, increases the reliability of the system and allows for additional functions such as actively dampening system vibrations.
The system offers maximum efficiency and service life of all components with minimum overall dimensions. The drive system is currently available in ratings of 500 kW, 800 kW, or 1,200 kW. The main benefits of the system are:
- No-load motor start-up with modest energy demand on the electrical system
- Soft start of the face conveyor which is gentle to all components, particularly the chain
- Maximum total torque available to facilitate heavy load start-up of the fully loaded conveyor
- Accurate load sharing between the drives for full utilization of the installed power
- Excellent overload protection in the event of sudden chain jams.
The first system was put into service in 1995 at the Twentymile Mine in Colorado, USA which today belongs to the Peabody Group. Since then the system has performed well, which has contributed to increasing Bucyrus’ sales of face conveyors into the US, Australia, Germany, the CIS, China, Mexico, Kazakhstan, as well as the Czech Republic. This drive system, represents state-of-the art technology and will continue to support the sale of longwall orders throughout the world for Bucyrus.