Question: different speeds depending on direction

[m00se]

Hi

I'm asking for your help for a mechanism:

- One axle in

- One axle out

- With input in one direction the output should be slow / high torque

- With input in the other direction the output should be fast / low torque

 

I assume something like this could be done using differentials but I can't figure it out. Alternatively I tried with a driving ring and idling gears but that wasn't very reliable.

Any ideas?

[ukbajadave]

Does the answer lie in a sliding worm gear? I'm not near my parts so I can't be any more help but I'll be following this thread as it sounds like an interesting idea.

[Gray Gear]

LEGO 46490 planetary gear wheel hub might work, it may be a wheel hub but it can be used to gear down fast/slow as well:

[ukbajadave]

What about the driving axle turning clutch gear with a half beam fixed to the central axle cross and an idler gear on the other end of the half beam which meshes with two different gearboxes (high/low)

When the driving axle is turned the clutch turns one way or the other until the idler gear engages, then it slips until release?

[1980SomethingSpaceGuy]

You may devise something based on this:

By the way, I highly suggest you give this channel a look. Nothing new for a long time, but it's a gold mine. 

 

[Gray Gear]

2 minutes ago, 1980SomethingSpaceGuy said:

By the way, I highly suggest you give this channel a look. Nothing new for a long time, but it's a gold mine. 

Agreed, I watched every single video a while back.

[m00se]

20 hours ago, ukbajadave said:

Does the answer lie in a sliding worm gear? I'm not near my parts so I can't be any more help but I'll be following this thread as it sounds like an interesting idea.

That's actually a good idea, I'll try it out.

20 hours ago, 1980SomethingSpaceGuy said:

You may devise something based on this:

[VIDEO]

Looks nice but it does result in two different output axles however. I'll check if I can combine them using differentials.

 

Edit: I got it working. First diff splits the input, the two yellow knobbed gears (or whatever you call them) are limited to rotating only in one direction. Then one side is geared up, and the second diff brings the two back together. Works very fluently!

 

 

Edited April 12, 2020 by m00se
Added stuff

[m00se]

Sadly I was wrong: if there is any load on the output axle it stops turning. Also tried with a worm gearing that slides but same result. Finally found out that the problem is that the output axle needs to turn in different directions. If I add or remove one gear so if works as a rectifier there is no problem and you can put load on the output axle. Suggestions welcome ;-)

[ukbajadave]

Does the output need to change direction?

[m00se]

2 minutes ago, ukbajadave said:

Does the output need to change direction?

It is a required for what I need.