Electric actuators for high duty-cycle positioning tasks

Recently announced by Thomson Industries, and available in the UK from authorised distributor Heason Technology, the new Electrak LL actuator series builds upon the Thomson Electrak range with what is reported to be a high-performance and high-efficiency brushless motor and integral electronics that eliminates the need for standalone control.

“The IP66 harsh environment rated actuator perfectly suits mobile battery powered end-to-end positioning tasks especially where high duty-cycle use prevails,” states Heason Techology. “As a compelling and cost-effective alternative to fluid-power cylinders, the Electrak LL series impresses for positioning and lifting applications used on mobile machinery, door, gate and hatch controls, pick & place and materials handling equipment.”

The Electrak LL complies to the railway standards EN 50155, EN 60077 and EN 4554.

Two models covered

The new Electrak LL series covers two models, with dynamic load ratings of 4 and 6 kN respectively. Both have static load rating to 18 kN and offer 100 to 500 mm stroke in ordering increments of 50 mm. The long-life ball-screw and nut assembly has a load locking feature and a holding brake to prevent back-driving.

“With a nominal 24 V DC input voltage, with a generous supply variation tolerance, the Electrak LL has a constant speed, regardless of the actual load, so predictable machine performance is achievable.”

Those speeds are 30 mm/s for the 4 kN version and 15 mm/s for the or 6 kN. The end-to-end position for each axis may be triggered by separate extend and retract inputs within the stroke, or with adjustable end of stroke limit switches facilitated with controlled braking, ensuring repeatable operation and protection for both connected equipment and the actuator.

Other controls and safety features built into the onboard control electronics include current monitoring that isolates the supply on overload, replicating a mechanical clutch. The actuator is also equipped with voltage and temperature monitoring, as well as load trip point calibration.

Corrosion protected casing

The Electrak LL is housed in a high corrosion protected aluminium and polycarbonate casing, designed for washdown, and including UV-resistant surface treatment. All external hardware fittings and a wide selection of optional front and rear actuator interfacing adapters are in stainless steel.

As with Thomson Industries’ Electrak HD series demanding environment actuators, the new LL is particularly suitable for pneumatic and hydraulic-to-electric application conversions.

The Electrak LL’s high-efficiency brushless drive system suits battery-powered applications, while the full load duty cycle is specified at 35%, “that’s 10 to 20% higher than for other comparable electric linear actuators”, points out Heason Technology. At reduced loads, the duty cycle can match 100%. Maintenance-free life is specified at up to 600 km actuator travel.