Edited by Mary C. Gannon
senior associate editor
Adaptable piston and cylinder sets from Airpot Corp., Norwalk, Conn., feature a graphite piston and borosilicate glass cylinder in which each piston is matched to fit the cylinder with extremely close clearances.
They offer low friction, responding to forces as low as a few grams and pressures less than 0.2 psi. Starting and running friction are nearly identical, preventing jerky, uncontrolled starts and providing uniform smoothness throughout the device’s full stroke.
Temperature variations do not affect them, and they run clean and do not contaminate surrounding components. No seals are required, and there are no liquids to leak.
Self-lubricating materials survive at high cycles. They do not heat up or materially change under conditions of rapid and/or continuous cycling and have a lifespan of multi-millions of cycles.
They can be used in many applications, including as linear bearings, vacuum pickups, inertia sensors, portable piston pumps, spool valves, flow indicators, pressure sensors, dispensers, pneumatic calibration devices, and power pistons.
Features include low mass, cycle life in the billions, no deterioration or change in performance due to age or non-use, responsiveness to low forces and pressures, ultra-high speed capabilities, and simultaneous linear and rotational movement.
Cylinders are available in bore sizes from 0.220 to 1.75 in., and lengths from desired stroke plus 0.325 in. to desired stroke plus 0.880 in. Friction is less than 1 g without side loads.