2 Speed Automatic Gearbox using a worm gear for torque detection (prototype)

[TechnicBrickPower]

 

This video present a 2 speed automatic gearbox based on using a worm gear for torque detection. The 2 speed gearbox works by using the linear counter-action force on the worm gear to connect a gear to create a second speed. This 2nd speed is added to the main drive path using a differential after being passed through a worm gear to prevent back rotation when the gear is disconnected.

 

 

 

 

[2GodBDGlory]

Interesting. I haven't watched the video yet, but is it working on a similar principle to my previous sliding-worm 3-speed auto? Obviously yours is more complicated, and probably smoother, but is the idea the same?

[erikhortsch]

neato!

[2GodBDGlory]

  On 9/26/2020 at 2:54 PM, 2GodBDGlory said:

Interesting. I haven't watched the video yet, but is it working on a similar principle to my previous sliding-worm 3-speed auto? Obviously yours is more complicated, and probably smoother, but is the idea the same?

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I now watched the video. It is quite different from my design, after all! I like the innovation! Perhaps the same shifting technique could be applied to larger linear gearboxes to get three or four speeds?

[Horologist]

The pitch of Lego gear teeth is about 3.2 mm (there are 10 teeth on the 4l gear rack). The L-motor might slow down during shifting too because of the force required to stretch the rubber bands.

Edited September 26, 2020 by Horologist

[TechnicBrickPower]

  On 9/26/2020 at 8:02 PM, 2GodBDGlory said:

I now watched the video. It is quite different from my design, after all! I like the innovation! Perhaps the same shifting technique could be applied to larger linear gearboxes to get three or four speeds?

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Hi 2GodBDGlory! I did see your worm gear idea...so yes that did make me think about them for this purpose! I think you could extend the length of the wormgear and get more speeds in there. However the slow transition speed is a big issue unfortunately.

  On 9/26/2020 at 11:37 PM, Horologist said:

The pitch of Lego gear teeth is about 3.2 mm (there are 10 teeth on the 4l gear rack). The L-motor might slow down during shifting too because of the force required to stretch the rubber bands.

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Oops bad measuring on my part ;) Yeah rubber bands always slow things down a bit too.