Anybody Seen A "3 Ring Speed Reducer"?

Thread Starter

Jon Chandler

Joined Jun 12, 2008
1,029
I've seen a wide range of machinery during my career, and rarely do I think "Huh? What is that?" I hope you'll be able to see this way-too-short video on LinkedIn of a "3 ring speed reducer" – I can't stop watching it!

https://www.linkedin.com/posts/thia..._source=linkedin_share&utm_medium=android_app

Apparently, its application is that of a planetary gear, perhaps with looser machining tolerances. The only reference I can find is to a Chinese company, Aikman Gearbox.

I can't find any drawings or longer videos. I'm having trouble wrapping my head around how these work!

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Alec_t

Joined Sep 17, 2013
14,280
I've not see one before, but from the pic it looks as though the inner gear, of slightly smaller diameter than the outer gear, has the same tooth pitch and hence fewer teeth than the outer gear. So one rev of the inner gear produces n1/n2 of a rev of the outer gear, where n1 and n2 are the numbers of teeth on the inner and outer gears respectively.
 

Thread Starter

Jon Chandler

Joined Jun 12, 2008
1,029
A friend of mine came up with this link on Tri-ring speed reducers. It somewhat explains their operation in a pretty rough translation.

The three bars have a rotating cam on each end, making them act like a 4-bar mechanism. One of those cams (maybe both?) is the high-speed input shaft, and the gear, one the low speed output shaft, spans the width of the three bars. Each bar is in contact with the output gear for 120° of rotation.

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Thread Starter

Jon Chandler

Joined Jun 12, 2008
1,029
Looking at the pictures in the above link I'm truly intrigued. They show that in addition to directly driving the cams, they can be driven through a set of spur gears (moderate additional speed reduction) or even using a worm gear reduction stage (large additional speed reduction). I can picture this arrangement driving the huge rotating drum kiln at a concrete plant or large ball and rod mills.

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