Engineers at Parker Hannifin Corp., Cleveland (, have developed the ETR Series of electric cylinders that use roller-screw technology. It gives users higher loads (up to 100 kN or 22,500 lb) and faster cycling times (up to 2-g accelerations), as well as 15 times the life expectancy of traditional ball screws. The units feature dual-direction angular-contact, taperedroller bearings, and high-load antirotate bearings. There are external ports for lubricating the bearings and screw, and the modular design accommodates seven different mounting styles. The cylinders are available in four profile sizes from 50 to 125 use in-line or parallel mounting.