Drive Solutions with Gear Units for Belt Conveyors in the Mining Industry
In the mining industry, drive technology has a decisive influence on conveyor performance and system availability. Three-phase asynchronous motors plus gear units have proved a robust, quick-to-install, low-maintenance variant here.
In mining there are typical areas of application where the axiom “Fit and forget!” applies. That means that all the technology used serves to maximise profit direct and just for this reason has to be favourably priced, long-lived, powerful and robust. Belt conveyors are also subject to these demands by mine operators. In this respect there is a number of important aspects that ultimately result in the perfect conveyor belt drive.
Siemens has decades of experience in bulk material conveyor technology. High availability, proven technology and low costs are the advantages of the drive solutions for these applications.
Gear Units with highly efficient Axial Cooling Fans
What exactly are the advantages of this gear unit solution? Whereas for lower outputs standard gear units are frequently used, individually adapted solutions are needed for conveyor belts that shift especially heavy loads – in some cases over many kilometres. Here thermal capacity is regarded as the decisive factor in the selection of the right gear unit.
In practice, the required output and desired rotary speed are specified by the operator as design parameters, which determine the heat to be dissipated, which in turn may correspondingly strongly influence the dimensioning process. This may partly result in operating conditions that make a gear unit advisable that is larger than the output originally necessitates.
So, if conveyor belts operate in climatic zones which are particularly warm or are even prone to extreme heat-cold fluctuations, a lot of attention has to be paid to cooling. Here the Siemens electrical group has invested a great deal in development and fitted its gear units with highly efficient axial cooling fans. These direct the air over the housing and ensure that the heat is drawn off from the housing. Specially designed air guidance hoods distribute the air evenly over the entire surface – that is, over all four sides.
For operators this has the advantage that they can manage with outputs of up to approx. 2000 kW without the need for an additional oil cooling unit. Optimum cooling is particularly decisive for the components and materials used, such as seals and gear oil. The cooling system ensures that the lubricating capacity of the oil is not impaired and the optimum carrying capacity of the gear teeth is maintained.
For this reason Siemens has developed correspondingly efficient cooling solutions for its three gear-unit series, which comprise a total of 46 conveyor belt drive sizes. So in many cases a smaller gear unit may prove to be sufficient. The high flexibility resulting from the wide range of gear units offered means that the gear unit solution can be tailored to fit the customer’s precise requirements. That is an important reason why this solution proves economical.
Compact Unit featuring easy Assembly and Installation
Particularly the extremely compact gear units featuring the patented self-aligning system offer even more advantages appreciated by mine operators. On these units the motor and the gear unit are fixed together by what is known as a bell housing, which contains the coupling as well. This means that the system operator no longer has the job of aligning the individual component assemblies, a process which normally calls for special knowledge and skills. At the same time the firm connection between the components gives markedly increased operational reliability. Another special feature of these drive units is that they can be installed as right hand and as left hand versions without the need to be converted.
The important thing is that users have to expend as little effort and money as possible on engineering, start up and operation. That naturally also applies to the drive, which Siemens delivers complete as a single unit.
The manufacturer calls this system concept an Integrated Drive System (IDS) and delivers ready-to-fit complete systems, from the control system, through the different starter solutions to the gear unit, the coupling and the motor.
This also makes customer service, which can be provided by a worldwide network, easier. Furthermore the manufacturer offers Condition Monitoring Systems (CMS), which enable continuous monitoring and can prevent potential problems. After all, large conveyor belts often run for many kilometres in remote areas in an environment which mining personnel seldom venture into. Incipient faults can therefore be identified more easily with the help of the Siplus CMS equipment.