STANDARD electric motors will be consigned to the scrapheap in many factories if current trends continue as expected. As manufacturers demand faster, more accurate equipment, the appeal of high performance motors such as servo and stepper motors grows.
According to Australian Baldor director, Daniel Vera, servo motors and stepper motors are more repeatable and responsive than traditional motors. He claims this helps reduce waste and improve process efficiency.
“On a machine that cuts wood for houses, such as roof trusses for example, if your measuring is more accurate, then the amount of cut off and waste you have in the wood is going to be much less. You are able to move it faster and cut more accurately so [the operation] is more efficient,” he told Manufacturers’ Monthly.
Efficiency gains are not limited to the process itself. Energy efficient motors are available which save on running costs. However, Vera claims many manufacturers are still failing to exploit this technology and are basing purchase decisions on upfront cost alone.
“The purchase price is only about 3% of the total life cost of the motor. Initially [manufacturers] pay a premium for the high efficiency motors but in the long term most people save on the payback. Payback period is generally about two years or two and a half years.”
Timely and accessible information, and more integrated communications on motor operation were also increasingly important to producers, Vera said.
“Even the basic sensors these days are including more communications so manufacturers know whether they’re working or not, so from a communication point of view and from a feedback point of view, you are able to monitor the equipment.”
While these advances lead to faster and more accurate results, Vera says some manufacturers are struggling to come to grips with the more complex technology.
Maintenance staff require skills in electronics and programming to repair the equipment, and manufacturers must decide whether to train staff, employ new staff, or to outsource maintenance functions to suppliers or third party contractors.
Vera urged manufacturers to re-educate themselves and keep abreast of new technologies. “What we see is that if they don’t move forward with the technology they just end up being left behind,” he warned.
Some will survive
Vera admits servo and stepper motors are not always the best option and traditional motors will continue to be used in particularly harsh environments and industries which require brute force from their motors.
Norman G Clark managing director, Rob Clark agrees. “If they’re working in a dirty environment or an environment that is particularly harsh in terms of air quality or moisture, a lot of these products aren’t capable of handling it so the developments are better environmental protection of the clutches and brakes.”
Clark believes enclosures for clutches and brakes, as well as friction linings, are all improving.
“As material development has occurred, [friction linings] have got not only equal to the old asbestos lining but better, and there are more options to be more application specific.”
In this branch of the industry the drive for efficiency is also clear.
“Everything’s heading towards using a disconnect type arrangement like a clutch to allow you to run a drive on either smaller motors, and therefore giving you energy savings...or to allow you on start up of a drive to use a clutch to slip, again allowing that electric motor to be smaller. By using a clutch, you effectively protect the motor from whatever you’re driving in terms of its load, its inertia, or its high cycling activity,” Clark told Manufacturers’ Monthly.
According to Clark, correct sizing is essential when choosing clutches and brakes. “Any moving machinery needs to be capable of stopping before it causes damage and correct sizing of brakes in this case, or disconnecting drives using clutches, is necessary to stop the equipment if something goes wrong.”
Before selecting clutches and brakes, Clark said manufacturers should assess their operations to determine requirements. “That it causes you to really analyse what’s right for that specific type of application and I can’t over-emphasise that enough. We’re constantly replacing other people’s mistakes who just bought on price or what’s on the shelf without really asking the right questions,” he said.
Clark suggests manufacturers should ask: “How do I get the best performance out of the product to give me the best value for the money I am spending.”