|GKN Wheels plant in Telford believes it will save some £25,000 per year following the installation of an ABB low voltage ac drive.
One of the plant’s production lines, which makes wheels for agricultural and construction vehicles, such as Caterpillar and JCB, includes a walking beam with reciprocating parallel bars to pass rolled and welded wheel rims from an oil dip to a flare press.
Kevin Evans, production manager for the plant, explains that a problem has been that as the beam reaches top dead centre, the larger wheel rims can cause it to over-speed, with the momentum then carrying them too quickly towards the press, which can then jam.
“This type of stoppage can take an average of two hours to remedy, resulting in lost production time and associated costs,” he says. So to maintain schedules the plant had to run overtime following such incidents, leading to the £25,000 estimate.
With Estil, a systems integration company, and ABB already on site investigating potential energy saving applications, Evans asked them to come up with a better control system.
Phil Lampitt of Estil, which designed the control system, explains that the system uses a 1.5kW ABB standard drive. At the beginning of the walking beam’s cycle, the drive starts and the internal timer runs it for one second at full speed. Then the drive is switched to two thirds speed and gradually decelerated. Hence the beam, carrying the wheel rim, slows as it approaches the press. As the wheel rim reaches the press, the beam triggers a limit switch that stops the drive to complete the cycle.
“We worked closely with ABB to fine tune the application to get a steady positioning of the wheel rims,” says Lampitt.
“ABB also helped us size the drive – particularly critical in view of the need to cater for the heavier rims in the range,” he continues.
“As there is limited space, we had to mount the drive externally. This lead to challenges from the harsh environment of the production building and we needed to specify an IP54 rated drive casing to resist the ingress of oil.”
Evans confirms that since installation of the drive system, the plant has not experienced a single stoppage on this part of the process.
“This is a significant saving for us and we are also looking to standardise on ABB drives throughout the plant to save further costs on our energy use,” he says.