Harmonic Planetary Gearhead

Harmonic drive transmissions are noted for their ability to reduce backlash in a motion control system. How they work is through the use of a thin-walled flexible cup placed inside a circular thick-walled rigid ring. An inside flexible spline has two fewer teeth than the circular spline, which forces the flexible cup splines to push deeply into the rigid ring while rotating. This method basically preloads the teeth, which reduces backlash. An elliptical cam enclosed in an antifriction ball bearing assembly is used as the rotating input
element.

According to HD Systems, Hauppauge, NY, the Harmonic Planetary HPG Series now provides the motion control and design engineer with a planetary gearhead that incorporates elements of harmonic drive gearing. The HPG Series has reduced backlash to less than 3 arc-min.

The planetary gearhead design is made possible by developing a ring gear that can flex in the radial direction, while maintaining high torsional stiffness. Similar to other harmonic drives, this radial deflection allows teeth of the internal ring gear to be pre-loaded against the teeth of the planet gears. The result is a planetary gearhead that provides consistently low backlash, high efficiency, and high output speeds.

This new planetary gearhead incorporates patented technology. Designers working on applications involving semiconductor equipment, machine tools, and automation equipment can take advantage of this product.

--TP

For more information: Circle 555 - HD Systems Inc., or connect directly to their website via the Online Reader Service Program at http://www.OneRS.net/102df-555