Harmonic Drives explained
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- Опубліковано 26 лис 2019
- This is a free preview of one lesson in the "Robotic Drives and Physics" course available on Jet Pack Academy and new for winter of 2019. In this lesson, Ian explains what a harmonic drive (or strain wave drive) is and how it works.
Preview and enroll in the course here: jetpackacademy.com/shop/robot...
Transcript:
Your setup was so clear that it was immediately easy to comprehend. Good teacher.
Agreed, reminds me of the old Docs from the 40s explaining planetary gears transmissions and rear differentials
Years ago there was a Visible V8 model that had a starter that consisted of a can motor that turned a sun gear that meshed with 2 planet gears. The planet gears meshed with 2 internal gears with different tooth counts. One internal gear was stationary and the other one was connected to the starter pinion. The starter pinion meshed with the engine flywheel.
He started explaining, and I couldn’t understand why he had such a hard time understanding it in school lol. It was so simple.
That's the best explanation I've seen so far. Took a good deal of effort to setup.
For years I have wondered how robots with compact reduction gear assemblies were able to work without backlash. I had always assumed there was a sun gear assembly inside, so it never occurred to me it was a "harmonic drive", which I heard of but didn't grasp the meaning. I learned so much today and it was awesome. Thank you very much, I needed that! :)
Super great explanation. One would think that the flex spline gear would fatigue over a short time, but they're so widely used in so many applications that it must not be an issue. Thanks for the great video demonstration!
Great explanation. Now I understand the mechanics behind my new telescope mount drive. Very impressive!
I had a great “Ah Ha” moment about 6 or 7 minutes into the video. I’m a now retired electronics technician who used to work in the production of printed newspapers. Equipment from a company called Ferag used harmonic drives and when we were trained on it the instructor told us what it did but couldn’t explain how it did it. To him it was a magical engineering marvel. In the years that followed we repaired them quite frequently. Usually the Flex Ring would crack and we disassemble the unit and replace it. I had a fair understanding of how it worked after working on them but you, my friend, brought it all together. I’m going to forward your video to my former coworkers who still have to deal with it. I’m sure they’ll appreciate it. Thank you.
goes from stories and anecdotes about harmonic drives to explaining them at 2:00
Zero backlash & fixed timing... 2 great attributes for a gearbox... 🤨 a lot of people don't realise just how important backlash , or rather lack of it , is.. anyone with a milling machine who trys climb-cutting better have NO backlash in their table feed... 😰
Great description, the use of the straight racks initially helped greatly to understand the theory behind these rather exotic & quite expensive units... 🤗
😎👍☘🍺
When you say, "fixed timing" do you mean the input side is directly proportional to the output side? I saw cyclonial might have a problem in this regard ( because the input side to output side is not strictly linear because each teeth engaging is not directly proportional?)
Man i wish i had a teacher like this guy, school woulda been great
Easist tutoial that I 've ever got.
I finally understand harmonic drives. In 12 minutes. Man that's stellar.
This is the most amazing and useful video i have seen in a long time. Thank you for explaining this. I was really struggling to understand exactly how it works. You are an awesome teacher.
I've read how this drive works multiple times but never were able to visualize how it works. It was a mystery to me up to now. Great teacher!
Considering buying a telescope mount that works on this principle and wanted to understand it. Your video helped a lot. The advantage of very low backlash in astronomical mounts is significant, as well as the reduced need for counterweights on the mount. Thanks very much.
Ha! We must be looking at the same new ZWO mount! There are also others on the market that now have me looking into this tech more. This video explained it perfectly.
@@lizards821 You're right! Check out the cloudynights discussion. It's the PEC that's inherent in these drives that convinced me to not buy it. Looks like a good mount for visual, but not for DSO astrophotography, which would be my primary use of it. Leaning toward the EQ6-R Pro when they come back on the market.
@@cmahar3 yikes yeah spending $2k for a mount that cannot really do dso is kind of a bummer, especially considering the eq6r pro is less than that. Cuiv the lazy geek here on yt also has some videos on his as well.
@@lizards821 Right? All DSOs aren't out of the envelope of this mount, just the small dim ones requiring focal length longer than 900mm. OTOH there are literally no EQ6R-Pro mounts available in the US or Canada right now due to supply chain issues, and there won't be for months.
Best explanation I've ever seen!
WOW What an amazing explanation. Thank you so much.
I have never even heard of these mechanisms before but I'm super glad I stumbled on this video. That was fascinating!
In the '70s, as a 12 year old, I had a Visible Wankel Rotary Engine model which was driven by a planetary gear harmonic drive. I always assumed that this was how it worked, I was never sure until I saw this.
Best harmonic drive mechanical explanation I've seen (out of at least a dozen I've come across)
I work for Harmonic Drive and it really doesn't surprise me that these things last. Much care an precision goes into making these.
Shared this video to my robotics class. Far and away the best video explaining how these drives work from the 5 I watched before this.
I understand it immediately after your demo with those straight gear. Very clear explaination.
Hands down ...the best video I have seen on harmonic drive.
This is the clearest demonstration and explanation I've seen in a long time. Thank-you.
This was fascinating. I've seen it explained a dozen or so times but this is the first time I've actually understood it.
Thank you!
Wow, you're a great teacher, your video is terrific and I now know something completely new about gear drives. Years ago I got a fanuc welding robot arm and was amazed at the zero backlash on the joints but never knew why it was possible until now. As for how to get 2 more teeth with the same pitch, it's hits me now that the outer ring is naturally LONGER than the inner one, hence can have 2 more teeth in its' path. However, sizing up the tooth depth to accomodate the mating, etc is a challenge.Thanks for this explanation and I'll look at more of your videos in the future.
Excellent demonstration! Thank you so much!
Thanks for the concise explanation. I can see that these drives have multiple applications beyond the world of robotics. As an astrophotographer who deals with backlash on a seasonal basis (ambient temperature variations) this technology would be exceptionally well suited to telescope drives. My impression is that this type of mechanism would be less prone to backlash due to temperature variation. Chhers!
Terrific illustration. Thanks for posting the video.
I appreciate the clear explanation and effort of building the demo rigs.
Amazing gears.
Thank you very much for the clear explanation.
To everyone wondering if you can use spur gears on the bearings instead of a flex spline, the answer is: yes. I was curious about this as well, so I drew up a harmonic drive in Fusion and 3D-Printed a model that uses entirely 3D-Printed parts except the bearings, which are fidget spinner bearings. My tolerances leave a lot to be desired, which may hide the reason for using flex-splines instead, but it is a fully functional gear reduction that uses spur gears all round and no belt/compliant mechanism.
Jake, I would love to see your model. I would like to build a drive and am researching different methods right now. What you describe seems interesting....
Thank You! I was wondering 😊. I love your simple description. You haven't by chance posted your STLs somewhere? 😊
We use these drives in our surgical robots. Love the clear explanation and linear props to illustrate the basic physics. Thank you.
Awesome Demonstration, you wrapped up the idea in a beautiful simple was with many tools
Thank you! Wonderful demostration!
man this was a perfect explination, very good job! amazing drive motor design... the minds that come up with these things
This is the best explanation of this mechanism I've ever seen. Thank you!
This is a great explanation - well done!
Beautiful simple explanation.
This is an excellent video . I was having serious difficulty understanding this drive and
your explanation brought it all together for me. I commend this instructor profusely.
Such an amazing demonstration!
I appreciate the effort you put on to explain. Well done!
You explain extremely well!
And your pronunciation is so clear. Cheers mate!
Thanks for the explanation. When I took aircraft maintenance our instructor had us make our own vernier scale using two pieces of paper with marks on their edges. It opened our eyes to the concept of a vernier scale. Later we had to manipulate a vernier coupling to change timing which was very simple for us. This differential of gear teeth I instantly understood from that course I took over fifty years ago.
Very nicely explained.
Great presentation!
Brilliant explanation, thank you for the clarity! This concept is really flexible (pun intended!)
The best explanation of this drive. Point!
Greetings from Munich, Tom.
Many thanks for the demo and nice explanation.
Excellent, thanks for taking the time to make this!
I can't thank enough to the person explaining very beautifully the concept of harmonic drive so good video ❤️❤️ love it it just instantly clicked in my mind how the mechanism works after seeing the demonstration
I have heard of this but had never had an explanation. You provided a very good explanation.
The explanation is so clear and fantastic, thank you!
It looks like a perfect job for a wire EDM machine. Great explanation. Thank you.
You Sir defogged my mind in 12 minutes on harmonic drives, THANK YOU.
thank you for this awesome explanation and demonstration
Great model and explanation.
Very well demonstrated. Thank you
Clear explaination and great video. Thank you
Excellent explanation, thank you very much!
Great explanation. Thank you for the video.
Thank you for an awesome explanation.
Fabulous demo and lecture. Liked and Subscribed.
Thank you very much for a very simple explanation of strain wave drives. One of the newer places that these drives are starting to be used is in astronomy, more specifically astrophotography. Astrophotographers are always looking for lighter weight, more powerful, more reliable and less power consumption in their gear, since often time hobbyist astrophotographers are out in the middle of some open field, far away from any power.
For the most part, telescope mounts fall into two categories, Alt/Az, or Altitude Azimunth and EQ, German EQ which means German Equatorial mounts For astrophotography, EQ mounts are much more common, albeit much more expensive. You can align one axis to the North Star, Polaris, and the mount will rotate around that point in the sky, and since all the stars and things in space also rotate around it, once you've selected your target, the mount tracks around the North Star, keeping the object in the center of the scope.
Strain Wave drives are now offered by two companies, ZWO and iOptron. Usually, a normal EQ mount requires a counterweight and shaft to balance the load on the 'Right Ascension axis, which is the axis pointed at the North Star. Having the system balanced keeps down tracking errors. The Strain Wave drive eliminates the need for the counterweight (up to a certain payload), thereby reducing the entire weight of the mount. It also tracks better and has zero backlash, which is something astrophotographers also are interested in.
So, yeah, Strain Wave mounts are coming, and they are going to be the future of hobbyist astrophotography. Because of you, I know a lot more about strain wave drives now than I did 45 minutes ago!
thank you for an excellent 👍 class, I have never seen a harmonic drive in rl, but now I know what it is. greetings from Cape Town South Africa.
Great demo!
Thank you! Wonderful explanation
Great teaching! I have learnt a lot. Thank you.
Love it!!! I need to make some of these but specialized use.
Awesome lesson, many thanks 👏👏👏
Brilliant teaching, well done!
Fantastic explanation and the hardware was really good. I now know 'Harmonic Drive' has nothing, at all, to do with music.
This is an amazing explanation. Thanks.
This video is incredibly well presented.
Your explanation was very easy to understand. Thank you
Such a beautiful explanation..
Superb video! Thank you! Now I know why grease for our Yaskawa robot harmonic drives costs quite a dollar. Thare is a company Harmonic drive, that is making everythig around this technology.
Thank you very much for the clear explanation! Love your videos
Great explanation! Thank you!
Been wondering how that works for a while. Thanks for making the video and explaining it
Thanks for the informative video! I didn't know I was curious about Harmonic Drives until I started watching your video. 8)
Excellent explanation.
Thank you for sharing
Excellent explanations !!!
thx for this very brief explanation. it gives me clear direction where i hv to go for my arm. thx alot :)
Great video! Thanks!
Glad to see you up and running again. Be well.
Thank you so much for this video, very well done!
This guy is a great explainer. Thanks for the video.
thanks for share your knowledge..
I must subscribe to the channel. Immediately and deeply attracted by the awesome demonstration and teaching. Thank you!
Best explanation ever, thank you !
Great job in explaining this
Awesome explanation. Nothing to say other than many thanks !
Outstanding it is Crystal clear now
Fantastic, thank you!
Excelente explicación
that was interesting. never heard of a harmonic drive but could see how durable and long lasting it could be. thanks for the info!
excellent explanation. thank you
Fascinating. Great explanation. Harmonic drives are showing up in telescope mounts and I wanted to see how they worked.
Really well done!