A new drive module designed for BHP Coal's Appin colliery near Wollongong, New South Wales, is expected to create strong interest from other mine operators.
According to SEW-Eurodrive, one of four companies involved in development of the drive module, drive options for longwall conveyor drives have been increased as a result of the design work done for Appin.
Described by SEW-Eurodrive as a highly versatile drive module configuration, the new design resulted from a complex product specification from the mine operator.
"They (Appin) approached Gulf Conveyor Engineering with a tall order," a SEW-Eurodrive spokesman said. Gulf engaged the specialised input of SEW-Eurodrive, G-Man Pty Ltd and Voith Australia, and other transmission suppliers.
"What was required was a system which could be a standard drive, suitable for various different conveyors, but suiting the needs of each at the same time. Some conveyors were to be a single drive and then upgraded to multiple drives at a later date, and others were intended as multiple drives in the first instance," SEW-Eurodrive said.
"The concept will also be used for tripper drives. Control of the drives was essential, as was proper load sharing. The drive had to be low on maintenance and highly reliable with a minimum of components and a minimum of complexity. A further requirement was that the main items of equipment were carried as stock and they had to have a favourable initial cost."
SEW-Eurodrive project engineer Stephen Koen said the specification was tough.
"What made it particularly challenging is that we were up against some other well known suppliers of hydro-viscous clutch couplings and drives," he said. "But a powerful motivator was that, after discussions with Gulf, we could all see the opportunity of developing a system suitable for many different conveyor and tripper applications and not exclusively for use underground at Appin."
Koen said space-saving features of the design were "a special consideration for this application" as some alternative methods of low speed hydro-viscous clutch drives used parallel shaft helical reducers. A substantial cut-away at the conveyor drive head was required to accommodate the wider drive.
"We use a bevel helical reducer, meaning that we could get away with a minimum (if any) additional cutting to fit the drive heads in place," Koen said. "This also allows us to relocate our drives very simply, and avoid the cost in dollar terms, as well as time, when an installation or relocation is required."
The G-Man/SEW-Eurodrive/Voith/Gulf drive configuration uses the Voith DTPPW fill controlled fluid coupling. One of the advantages of this coupling is it uses mine water rather than expensive hydraulic fluids that have to be changed frequently and regularly. According to Voith, the use of mine water produces maintenance cost savings and allows the operator to use a non-toxic, inexpensive environment-friendly fluid.
"Due to the design of the DTPPW controlled fill fluid coupling, we can have an unrestricted number of starts per hour," Koen said. "G-Man's design also flange-mounted the electric motor to the Voith fluid coupling and then flange-mounted the fluid coupling to the input of the SEW-Eurodrive reducer. This means that alignment is no longer a problem, either in assembly or during maintenance on the surface or underground.
"We also save considerably when it comes to installation, as this drive design utilises a rigid coupling mount on the pulley head shaft and a torque arm link under the electric motor."
A skid under the drive did not compete with the flange mounting for rigidity in the drive, but did provide a convenient location for the torque arm, Koen said. It also provided a mounting surface for wheels which allowed the complete drive to be towed underground, and positioned conveniently for installation. "Again, this represents substantial savings in installation, and maintenance if and when required," he said.
