How James Watt circumvented the Crank - Mechanisms of the Industrial Revolution

for most the steam engine is the symbol of the Industrial Revolution it was the breakthrough needed to allow a multitude of machinery to be powered and in this video we'll be exploring the role at this strange mechanism had Alice just before we get started I would like to say that this video is brought to you by the great courses Plus and you can go to the great courses plus com forward slash makers Muse to sign up for a free trial today [Music] so while steam power did exist for quite some time before hand it was the innovation to convert reciprocating motion that is forward and back into rotary motion that really established steam engines as a backbone of the Industrial Revolution so how would you do that well the most obvious way to any engineer would be to utilize a crank such as this one James Watts saw an opportunity and set out to improve the new common atmospheric engine by converting its movements into rotary motion but there was one major issue the crank was patented yep there was another James Picard who had managed to secure a patent for the use of a crank in converting the engines reciprocating motion into rotary motion instead of Licensing which he flat-out refused to consider what was forced to engineer an alternate method to circumvent the existing patent and this was the result the Sun and planet gear sight note is apparently still in debate with a James or an employee William Murdoch count the idea first but regardless the mechanism was suitably different to avoid infringing on the patented crank it's also worth noting that this was only one of several alternate methods device and then patented by what he was a massive fan using the patent system to stifle competition anyway moving on how does it work to try and better understand the Sun and planet gear linkage I created this model in fusion 360 I'll be honest it took me quite a few shots to get right so much respect to those guys back then with all the parts printed out and assembled let's have a look at how it functioned in the actual steam engine there would be a piston over on this side the link connecting to it on each stroke of the planet gear which is fixed to the arm orbits around the Sun gear and teeth engaged causing the Sun gear to turn creating rotary motion I should mention that without a flywheel to maintain momentum the Sun gear is difficult to drive as it was originally intended on this model but we can also turn it backwards by rotating the Sun gear and then we get reciprocating motion by forcing the arm up and down keeping the gears engaged is a little bit tricky requiring this plate here this little plate confuse me hugely initially I'll be honest but it has no play in the force transfer at all it simply is there to keep the two gears mesh together prevent them from falling away from each other during the motion so what advantages does this make isn't have over a regular old crank well not a huge amount for the purpose of a steam engine let's be honest it's less efficient and part of more costly to manufacture and James what did explore many other alternatives as mentioned but he settled on the Sun and planet gear for his steam engines as that was the best option available to him at the time one thing I did notice when playing with a 3d printed model however is one of gearing on a crank a single full rotation will result in a linkage moving one full stroke forward and back but with the Sun and planet gears there's slightly different here you can see with a 1 to 1 gear size ratio that one full rotation of the Sun gear actually only results in half a stroke requiring two full rotations for a full stroke forward and back giving us an effective 2 to 1 gear ratio it's driven from the Sun gear or a 1 to 2 gear ratio if driven from the piston like so as it would have been originally in the original steam engine however I'm not sure how this would have affected the performance of the steam engine but this kind of behavior makes this kind of gearing nose epicyclic gearing so powerful and still widely used today albeit in a slightly different form this is my run-of-the-mill cheap cordless drill this drill actually contains what's known as a planetary reduction gearbox instead of having one planet it has several three or more per reduction stage rotating around a Sun gear instead of a linkage to create reciprocating motion there's what's known as a carrier plate which holds those kind of views in place and a stationary ring gear to measure those sonic gears which are now free to rotate and pass the reduction forwards to the next stage through the carrier planetary gear trains are durable as as many teeth in contact at any one time it's unlikely to shear them under heavy load and they cancel a very high reduction in a compact form factor this is one of my favorite 3d printing examples of a planetary gear box downloaded from fever's links in the video description as a gear reduction of four to one per stage you can have as many stages as you like daisy chain together to get your desired speed decrease and talk increase pretty neat huh in the end the patent for the more efficient and cost-effective crank did expire and James Watt adopted it into his steam engines so the less efficient Sun and planet gear but personally I find this to be quite a beautiful mechanism regardless and if you ever get a chance to see a working what steam engine of the era you'll see what I mean a big thanks to the great courses plus for sponsoring this episode on makers moves if you enjoy learning new things in incredible detail which you probably do if you follow this channel then you'll love the content on the great courses plus the great courses plus it's a subscription on-demand video learning service which gives you unlimited access to over 7,000 top-notch lectures and courses from top professors from the Ivy League and other great universities globally as well as experts from places such as National Geographic and the Smithsonian as part of my research for this episode I've been thoroughly enjoying the 36 part lecture series on the Industrial Revolution taught by Professor Patrick alert the level of detail on each 30-minute lecture is insane and it's hugely interesting like did you know the origin of the term broadcasting comes from farmers literally just chucking handfuls of seeds across their soil yeah I thought that was pretty neat it's all in video format which is how I like to learn so head over to the great courses plus com slash makers muse or follow the link in the video description to start your free trial today and also helps the channel out so I can continue to bring like this in future if you wanna see future it's really putting projects tutorials and more mechanisms from the Industrial Revolution we sort of subscribe to makers news my name is Angus and look for the scene again very shortly happy printing bye

Channel: Maker's Muse

Views: 860,484

Rating: 4.8199 out of 5

Keywords: 3D printed, sun and planet, gear, steam engine, mechanism, mechanisms of the industrial revolution, industrial revolution, i3, gear linkage, crank, alternate, design, 3D, CAD, fusion 360, 3D Printing, courses, video, maker's muse, makersmuse, angus deveson, australia, james watt, steam era, patent, mechanical

Id: 4bXjAyfDfm0

Length: 7min 8sec (428 seconds)

Published: Sat Apr 22 2017

Reddit Comments

[u/faizimam]

Makers Muse is great. He mainly does 3d printings subjects, but his mechanical engineering knowledge is fantastic.

Though I forgot how poor his audio quality was in his older videos.

[u/christonabike_]

Ah the history of patent trolling - a long line of problems that shouldn't have existed in the first place and could've all been solved at once by just abolishing the exploitive institution of corporate private property.

... Cool mech still.