Product category:
Metals processing plant and equipment
News Release from: David Brown Engineering | Subject: Gearboxes
Edited by the Manufacturingtalk Editorial
Team on 15 August 2003
Hoist design improved without rebuilding
Gearboxes for the main hoists at the Corus Port Talbot steelworks have been re-engineered to radically improve the design and eliminate shaft seal problems without rebuilding the hoist.
Gearboxes for the main hoists at the Corus Port Talbot steelworks have been re-engineered by David Brown Engineering in conjunction with Corus Engineers, to produce a drop-in solution that radically improves the original design and eliminates shaft seal problems without rebuilding the hoist The new drop-in units were designed for mounting in the precise configuration of the original gearboxes, but incorporate technology that ensures they require less maintenance and are easier to work on for whole life cost benefits
This article was originally published on Manufacturingtalk on 4 Nov 2002 at 8.00am (UK)
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The main hoists at Port Talbot transport molten iron from the ironworks and scrap steel to the 'BOS' (Basic Oxygen Steelmaking) furnace.
They are, in effect, very large rail mounted cranes capable of conveying loads of up to 500 tonnes.
Installed 30 years ago and still operating safely, they nevertheless required high levels of maintenance.
A specific problem associated with the ageing of the gearboxes was oil leakage resulting from the infiltration of abrasive materials.
Over time, metallic dust caused scoring to the shafts of the original gearboxes making it impossible to prevent large-scale oil leakage.
This was expensive in terms of oil usage and maintenance.
One example of how David Brown sought to 'design out' potential problems is the innovative installation of levelling pads on the gear units.
Because the cranes are mobile, running on rails throughout the length of the works, they can be subject to a certain amount of unevenness.
This, coupled with their sheer weight, means that a degree of 'twisting' occurs which is potentially harmful to precise gear alignment.
Levelling pads make it possible to check alignment at any point in the cycle of the crane without removing gear covers in the hostile environment.
The gear units have twin input motors; one driving through an epicyclic stage, the other through a double helical stage.
Either motor can drive at half speed should there be a failure.
Each gear unit transmits 770HP at each input shaft motor.
The motor speed is 585rev/min to produce an output shaft speed of 84rev/min when both motors are driving.
When the epicyclic input shaft motor is held stationary the output speed is 41rev/min and when the other input shaft is held stationary the output speed is 43rev/min.
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