Low-friction counterbalance

June 9, 2008

Airpot Corp. has designed a long-length (up to one metre) Airpel Anti-Stiction actuator that meets the needs of coordinate measuring machine manufacturers for a low-friction counterbalance device to allow smooth movement and precise positioning of the z-axis measuring arm while manipulating the device through its measurement range.

The company says smooth, responsive and accurate movement of the Z-axis measuring head on coordinate measuring machines and other XYZ gantry systems utilizing linear motors are crucial attributes manufacturers seek when developing these devices. A counterbalance system is often used to reduce the weight and drag inherent in the linear motor driver and associated liner bearing guide systems. The company says Airpot's cylinders solve this problem utilizing a simple pneumatic cylinder with a revolutionary internal design that allows for virtually zero friction while precisely controlling the amount of counter force needed to eliminate the effect of driver and probe arm mass.

They are built using a graphite piston / borosilicate glass cylinder combination in which each piston is selectively matched to fit the cylinder with extremely close clearances. They have unparalleled low friction, responding to forces as low as only a few grams and pressures less than 0.2 psi.
www.airpot.com/beta/html/exhibit31.html