Rodless pneumatic cylinders are a highly-appealing linear actuation technology that can save enormous space on machinery and now have higher load capacities.
Rodless pneumatic cylinders are a highly-appealing linear actuation technology that can save enormous space on machinery, but compared with conventional rodded cylinders their performance is often regarded as inferior. A novel new rodless cylinder design from Festo incorporates technology that delivers a step-change improvement in life cycle, load capacity and running costs - along with much simpler system building. Six diameters of cylinder ranging from 8 to 40mm are available in Festo's new DGC range, offering movement speeds to 3metres/second.

Despite compact dimensions, the largest cylinders in the product family will carry loads up to 50kg and accommodate very large forces to 7000N and torques to 380Nm - outstanding performance levels that provide great application flexibility.

Moreover, when applied within such application guidelines, DGC cylinders offer the same high life expectancies as conventional rodded cylinders.

Unbalanced loads are also possible and Festo offers a free design tool that allows users to calculate the loading for any application situation; Festo additionally offers a service to calculate the life expectancy of cylinders for any given application.

Higher running costs because of air leakage from rodless cylinders - which typically have a soft seal between the piston and load - is another common concern of automation builders.

The new sealing mechanism on DGC has virtually zero leakage.

A new clean-line aluminium body and piston-to-carriage connection mechanism are at the core of this shift in performance.

These provide improved rigidity and strength to support the increase in load capacity, while substantially reduce the manufacturing bill-of-materials and costs.

The highest specification ball bearing equipped guide is crimped into position during production for instance - eliminating multiple bolts and assembly operations - allowing Festo to offer the rodless cylinders at extremely competitive prices.

Three types of carriage guide are available depending on the actuation requirement and load: a basic version which has a guide with a plain polymer bearing suitable for light loads; a larger version for medium loads - which has a plain bearing for economy but one which is factory-adjusted for good performance; and a high-performance guide with stainless steel recirculating ball bearings.

The latter type will handle very large loads, and performs very well even with loads that apply a torque moment to the carriage - offering as much as three times the load handling capacity as some current generation products.

Backlash for this actuator variant is zero.

In addition to advancing rodless cylinder performance, Festo is offering the cylinders in a form that greatly simplifies specification and use.

Thanks to the DGC's novel sealing mechanism which connects the carriage to the internal piston via a zip-like seal uniquely positioned at 45 degrees on the extrusion, all the cylinder's fundamental accessories are available on one face - for very easy access and installation.

This includes the mountings which can be screwed on from the side, the adjustable end position stops, and the air connections - both of which are located at one end for ease of connection by virtue of a chamber incorporated into the body.