Gear speed multiplier for pump 2

[erik3000]

I have an unusual situation where I am trying to run a pump manually with a mechanical device that is very slow (40 RPM max) but high torque (1500 in-lbs), while the pump should be run closer to 1500 RPM and 100 in-lbs torque.

Most gearheads seem to be made to reduce high speed motors, while I'm looking for the opposite (convert manual crank to motor speeds). Is this as simple as turning a gear speed reducer around the other way? Any advice where I can find what I'm looking for?

 

[MikeHalloran]

Driving a crank arm with a crank arm introduces an orbiting force on both objects, which gets worse if the shafts are not perfectly aligned, or if either object has any compliance in its suspension. The vibration produced will be, at least, unbelievable.

Did I mention I think it's a bad idea?

Have you considered hydraulic quick-connects?

Have you considered multi-jaw couplings with a guided/compliant shaft, starting at ~zero speed while coupling and at pump speed while coupled?

Have you considered an eddy-current or other magnetic coupling?

Have you considered a flat plate friction coupling?



Mike Halloran
Pembroke Pines, FL, USA

 

[erik3000]

For what it's worth I drew a simple diagram to show what I am after. A special handle can be made to attach to the gearbox input shaft for the crank arm to latch onto. That's not too problematic, especially at the speeds of the crank arm. It's the gearbox that I am not sure is possible.

 

[3DDave]

One component that needs to be considered is a place to react the difference between the input and output torques and any non-torque reactions.

 

[moon161]

Maybe something from this catalog:

http://www.winsmith.com/documents/D90-TYPE_SE_Catalog_290j.pdf

 

[moon161]

Do consider the type of reducer. I don't think a worm gear reducer will run backwards for you too well. A set or 2 or 3 'regular' gears will.

http://www.icrepq.com/icrepq-08/398-jaliu.pdf

or try the baldor catalog

http://www.baldor.com/support/Literature/Load.ashx/BR1600?LitNumber=BR1600

 

[ivymike]

I was going to suggest a rack and pinion setup with something to let you accept reversing motion on the input, but perhaps you can use a friction drive like an old bicycle headlight generator...a 1 inch rubber wheel riding on the OD of a bicycle wheel...robot turns the bike wheel and little wheel turns the pump. You could probably even turn a cogged belt inside out and mount it on the bike wheel with rubber cement, and then 3d print a cogged little wheel for the pump.

 

[hydtools]

What flow do you need? It looks like you are using a pressure requirement to select a pump when you should be using a flow requirement.
Use a larger pump that will deliver the flow you need at 40rpm speed.

Ted