Machine Design [1]

On a roll with linear actuators

A linear-motion system designed by Amacoil Inc., Aston, Pa., is a sturdy, reciprocating platform that limits vertical and horizontal movement to ±0.001 in. and has virtually zero play in any direction. This makes the system suitable for load-bearing applications requiring precise back and forth movement, such as laser scanning parts, PCB measurement and cleaning operations, or bar-code scanning on batch parts.

The unit combines a 24 X 17 in. loading platform with a support/guide rail system, a casehardened shaft, and an Amacoil/Uhing RG rolling-ring linear actuator. An RG actuator permits variable pitch and automatic reversal without using complex controls. This instantaneous reversal capability avoids sudden or jerky movements, and makes the drive useful for winding, spooling, slitting, spraying, and other reciprocating motion applications.

The system can reach speeds of 13 ft/sec over travel distances of 16 ft, produces 800 lb of axial thrust, with accuracy within ±0.005 in.

Applications that call for an indexing or positioning motion can use an optional RS rolling-ring drive. This fixed-pitch RS actuator is designed for indexing, measuring, positioning, and PLCcontrolled applications. It features speeds of 5 ft/sec, distances to 16 ft, 500 lb of axial thrust, and accuracy ranges of ±0.005 to ±0.0004 in., depending on the type of controls. Maintenance includes lightly lubricating the shaft.