Good for simple applications like automotive power window actuators, or demanding duty in heavy or high-precision machinery, this new screw drive offers low-friction, vibration-free operation, high force magnification, and the ability to accept input speeds exceeding 20,000 rpm.

Fine-pitch spindle threads, corresponding grooves on the rollers, and additional coarser roller grooves transmit force to the nut. Design options permit a wide range of feeds per revolution. These include rollers with circular grooves for both nut and spindle engagement, or rollers with threads engaging the spindle and circular grooves engaging the nut.

In addition, hollow-shaft motors can be installed directly on the nut, making a self-contained actuator with a power/weight ratio similar to or better than hydraulic actuators.

George Jaffe, Schneeberger Inc., 11 DeAngelo Dr., Bedford, MA 01730; Tel: (617) 271-0140.