EA proof-of-concept hybrid ac traction car was a small, but important, part of the Hydramatic Engineering stand at AIMEX 2003.
The small, partially perspex-covered vehicle is designed to show how trailing cables are not needed underground for 4WD vehicles, for which read shuttle cars and similar equipment.
A diesel generator set with an ac alternator is used to power up the triple variable frequency drives to run the traction and steering motors.
The major feature of the proof-of-concept unit is that the wheel speed is adjusted by the steering angle, important for vehicles like shuttle cars that must turn 90º angles in very muddy conditions.
Testing of the prototype, developed by a team of 23 engineers led by director of engineering Paul Charlton, is continuing on surface with the aim of retrofitting the system to an existing underground unit in early 2004.
Charlton told Australian Mining that concerns about particulate being generated by a diesel engine in an underground environment are not warranted.
He says a proved diesel engine with fuel injectors will be run to use the ac alternator, and the new ultra clean diesel fuel now being introduced will ensure the diesel particulate emissions are not a problem.
The proof-of-concept vehicle was developed at its own cost, without government funding, by Hydramatic and a local partner specialising in electrical/electronic work, Machinery Automation Services.
So far around $1m has been spent on the project that – because it incorporates known technologies – is not patentable. However, as Charlton stresses, the key to the vehicle is the intellectual property contained in the software.
Also on the Hydramatic stand at AIMEX 2003 was the new series 2000 roof bolter, which is an extension of the 4000 series that will continue to be available.
Advantages of the 2000 series are minimal maintenance, with the only regular maintenance required being the chain tension.
The unit has two internal jacks, with a centralised balance. At its heart is a diamond back slide that gives one hundred times the surface contact compared to the 4000 rigs.
It also incorporates a triple china action, and is advised to allow ease of change out if an accident does occur.
While not on show at the exhibition, Hydramatic is also due to release shortly in South Africa a new twin boom mobile bolter, developed especially for the Middlevolt mine of SASOL.
This is believed likely to interest a number of Australian coal miners who want to reconsider the use of twin armed mobile bolters in cut and flit operations.