Drives and Controls Magazine
Contact-free transfer system can transmit 240W across 5mm
Published:  29 April, 2015

Weidmüller has developed a contact-free energy transmission system designed specifically for industrial applications. The FreeCon Contactless system uses inductive resonance coupling to transmit up to 240W of power (10A at 24V DC) across an air gap of up to 5mm, with a transmission efficiency of up to 90%.

Weidmüller claims that it is the only contact-free energy transmission system that can be switched directly by a PLC, without needing an extra contactor. The wear- and maintenance-free system measures 100 x 100 x 47mm, and is claimed to have twice the power density of rival systems. The IP65-protected modules can be mounted directly or using a bracket, allowing them to be used in applications such as robotics.

A coil in the transmitter module generates a magnetic field that is picked up by another coil in the receiver. Weidmüller has come up with a thermal management system that, it claims, keeps the heat generated within manageable limits. Energy can be transferred through most solid or liquid materials – but not metals.

Unlike conventional plug-in connectors, the receiver can be coupled with the transmitter from any direction, and can also rotate.

Weidmüller says that the FreeCon system will avoid problems such as burned-out, warped and dirty contacts that are common causes of failure, particularly in applications requiring frequent plugging. Plug-in robot tool-changers, for example, can perform several hundred connections every day, can suffer from high contact wear and erosion. Maintenance on such systems can be costly, and reliability and production quality can suffer.

Weidmuller's contact-free power transfer system can be controlled directly by a PLC

Other potential applications include rotary indexing tables, driverless transport systems, and applications that currently rely on sliprings. New applications could also emerge, automating connections that previously needed to be plugged in by hand.

The first commercial applications, in German car body plants, are said to be at an advanced stage of planning.