Joy said the 1000V VFD has been rigorously tested and proven in the most difficult conditions on continuous miners, shearers and the Flexible Conveyor Train (FCT).

After prototype testing during the early part of 2003, the first two pre-production models of the 10SC32 were recently shipped out of Joy’s US-based Franklin facility, bound for Drummond Coal Company’s Shoal Creek mine.

Currently the Joy shuttle car products utilise a variety of different drives including, DC, AC/DC and AC. These drives have been developed over the long history of the shuttle car product line.

“One of the reasons to apply the VFD drive on the Joy shuttle car is to benefit from features like regenerative braking and infinitely variable speed control. These features will allow the operator to approach and ‘spot’ the shuttle car precisely and smoothly at the rear of the continuous miner or the feeder breaker,” said Mike Adamczyk, Joy’s vice president global engineering.

Other advantages include a tighter turning radius that is achieved by being able to drive the inner and outer wheels at different speeds. This feature also reduces ‘skidding’ and thus minimizes bottom or floor damage.

Finally the shuttle car tramming speed can be increased from approximately 6.5 km/h to 9 km/h with direct benefits in increased production.

Asked about the possibility of retrofitting a VFD system to an existing Joy SC, Adamczyk said it is an area that Joy is seriously considering.

“While Joy captures almost all the OE market in the US, there’s a large portion of the market that’s going to after-market business,” Adamczyk said.