Harmonic Hyperdrive

This CAD model was designed by Oskar van Deventer, copyright (c), 12 July 2015.

Harmonic Hyperdrive is a gearing contraption that achieves a 300 to 1 gearing ratio. It is a combination of a strain wave gear, also known as harmonic drive, and the Grinder Gears. The mechanism has two sets of cycloid drives, one with a gearing ratio of 26 to 24, and the other 25 to 23. The resulting gearing ratio is 25x24/2=300 to 1.

Harmonic drives are best known for their high accuracy, not any slack or backlash, and high reduction ratios. The reduction ratio of a Harmonic Hyperdrive is proportional to the square of the reduction ratio of the equivalent harmonic drive. So it can achieve even higher gearing ratios while keeping the number of gear teeth limited, and the size of the teeth not too small.

After seeing this video, Dr. Ingolf Schäfer of Harmonic Drive AG told Oskar that they had conceived a similar (same?) concept in the 1990's. However, only some lousy sketches are left. The reason that Harmonic Drive never pursued this concept that there was no market for gear drives with such extreme reduction ratios.

Here are some links about this design.
https://www.youtube.com/watch?v=AyRJ0hO-s6M

Feel free to 3D-print an extra sample to give to a friend, as long as you mention the designer and don't charge money.

If you are planning to sell some samples, then please contact me for a license agreement. The royalty fee is 10% of your selling price.

Please do not upload the design to a commercial service, or redistribute the design in any way other than linking to the YouTube video: hhttps://www.youtube.com/watch?v=AyRJ0hO-s6M

Enjoy!

Oskar
26 July 2025

Contact: 
https://oskarvandeventer.nl/index_contact.php?subject=Print%20It%20Yourself