Where tubular linear motors blow away pneumatics

For factory operators looking to save energy and costs, an obvious first place to look is compressed air.

Compressed air is highly useful in many industrial applications, and some sites spend up to 30 per cent of their electricity bill generating compressed air.

Pneumatic actuators, which run on compressed air, have been around since the Second World War. They are well-understood, cheap, and suited to harsh environments. However, they also come with their penalties.

Obviously, compressed air must be generated to power them. Depending on the expansiveness of a factory, this can mean numerous compressors and/or a complicated reticulation system. A reliable level of pressure must be maintained, or pneumatics will work poorly or not at all.

Air leaks can be expensive. According to a leading compressor technology company, one leak in one unit costing 15 cents/kW/hr to operate will represent well over $2,000 a year to a power bill.

With a single point of failure – for example air leakage at one location – the air pressure of the whole plant will drop, and operations will be affected.

Then there is the noise.

“If you are working in or visiting a factory, you will usually hear a lot of noise,” explains Heng Luo, Product Manager, ANCA Motion.

“And that’s one big advantage servo-controlled linear motors have against pneumatics.”

Linear motors — for example screw-driven and tubular linear kinds — are newer than pneumatic or hydraulic options, but are preferred for certain applications. Instead of a piston in a cylinder — driven by compressed air or an incompressible fluid — tubular linear motors use magnetic flux to create motion. They aren’t as cheap in upfront costs compared to pneumatics, but offer vast benefits in aspects including accuracy, cheaper operating costs, and flexibility.

Pneumatics can move quickly and forcefully from one point to another (and hydraulics quicker and more forcefully still, for the same size) but with little positional control along the stroke.

ANCA Motion’s LinX M-Series offers 10 micrometre resolution, as well as velocity up to 10 metres per second and maximum acceleration over 30G. The M-Series comes with an integrated position sensor, with precise positional control. It can also achieve a continuous force of 90 – 160 Newtons, and a peak force of 1,200 Newtons.

An estimated payback period versus pneumatic cylinders — which, with their form factor and mounting design, the M-Series is a neat substitute for — is only 18 months.

One area of obvious advantage over pneumatics is the ease of reprogramming between jobs.

A recent application for a customer’s forming machine substituted LinX motors for pneumatics to move a cutting bed. Changes for different workpiece lengths could take six to eight hours for the painstaking recalibration of air pressure. Such adjustments now are a quick change in servo drive parameters — a matter of seconds. The improved positional control has boosted throughput by 50 per cent, with the massively improved precision allowing the process to be confidently sped up.

ANCA Motion’s linear motors were originally developed for sister company ANCA CNC Machines’ FX Linear and MX Linear tool and cutter grinder machines. ANCA is a leader in CNC tool grinding technology, with a series of world firsts since beginning in 1974. The M-Series have been developed within a culture of world-class engineering, developing machine tools where micron-level precision is essential.

The LinX M-Series Tubular Linear Motor has a failure rate of less than 0.03 per cent.

Robust support is offered through an international network of 125 engineers in strategic locations.

Learn more about the LinX M-Series here