High-torque motors vs. high-ratio gearboxes

Presentation for the IROS 2021 workshop "From Gears to Direct Drive: Recent Trends and Opportunities in Actuation".
For more details on the scaling laws analysis (slide 7), watch the following video:
• High-ratio gearboxes v...

[@user-fm4hd6wr4k]

In fact, the direction I have been paying attention to is the same as your work, and your work has inspired me a lot. I originally thought that the wolfrom scheme was too inefficient to be usable, although Japanese scholars have already provided good optimization schemes. If your results are very good, it will prove that my idea is completely wrong. Looking forward to the test results.

[@lostguy2023]

Prof. Tom,... excuse me Sir but I've been meaning to ask. How did that novel Wolfrom planatary gear turn out? I'm building an ebike for my own personal use and have yet to settle on the ideal powertrain for it. (my hobby) Ebike motors have always seemed to be all over the place to me, (we usually just make due), so I've decided to throw together my own with the focus being primarily preformance, and not just cost. It'll be just one of a kind, but as a platform to inspire others, I am hoping it'll punch WAY above its weight class. Any suggestions?

[@anthonywalker6168]

If you are willing to tolerate some increased maintenance and the occasional seal failure and leak, a medium pressure hydrostatic reducer coupled to an electric motor will work wonders… Good luck to all.

[@0raibi]

Hi Tom. I'm currently working on a project for camera robotic arm and I wonder if you were me what would you choose as a gearbox to ensure maximum smoothness, lowest vibration, and low backlash?

[@mauricioredez1641]

I have the same project and the same question

[@ds-k7878]

이거 이렇게 복잡하게 생각 안해도 되 . 어차피 다이렉트 드라이브의 자석과 코일의 접촉점에서 부터 회전축 중심의 R 값이 가지게 되는 토크와, 감속 모터의 모터의 자석과 코일의 접촉점 반경 + 기어트레인들 R 값이 더해진 상황의 토크는 일치함. 다만 기계식 접촉점이 많은 감속기형 모터가 마찰에 의해서 전력을 물리적 에너지로 변환 시키는 효율이 떨어지는것 뿐이고, 다이렉트 드라이브는 물리적인 회전 반경이 크므로 관성이 더 클 뿐이야.

[@kopeezie]

You mention upfront cost in your presentation being higher for DDR applications. I would like to have this clarified that it is upfront costs and not life time cost of operations. DDR life, reliability, and less degradation is found to more than make up for those upfront costs. Thus resulting in lower operational costs and support. Give a looksee at Yaskawa's DDR training material regarding this: ua-cam.com/video/GvMNloaNMDE/v-deo.html