Rolamite Linear Actuator Cuts Friction and Complexity

The payload can mount to either the carriage, a gantry-type actuator, or the housing (for pick-and-place applications). A tensioning band woven through the rolamite bearing, which is turned by a servomotor through a worm drive, propels the carriage along a track. The housings and track are made of aluminum to reduce weight.

The bearing is formed from rollers constrained by a Mylar-film or stainless-steel tension band wrapped in an “S“ configuration. The band is perforated to prevent slipping and provide precise position control. A double “S” wrap ensures the pure rolling motion is completely converted to ripple-free linear motion. Positioning is governed by a linear scale or encoder.

The bearing includes the drive, reportedly reducing complexity, cutting costs in half, and extending the operational life because most friction is eliminated. Payloads under 2 lb can be moved by a 5-W motor. Nominal speeds range up to 20 ips with strokes as long or short as the application requires.