Monday, November 28, 2011

Thoughts on Hydraulic Tank design for Power Cube

I know how I'm going to build my hydraulic tank. I've settled on a plan and I'm doing it. Still, the more I read, the more questions I have. The design I'll be building will work and be plenty sufficient, but perhaps it could be improved...

Painting the inside of the tank

It's not clear whether or not the inside of the tank should be painted. Some old hands say that it's not a concern. Others say that it is. I decided not to paint the inside of mine.

Mesh Filter on the Tank Intake

The design calls for a mesh strainer on the tank intake. This guy suggests that such strainers can be more harm than good. Most contaminants enter the system through hydraulic cylinders and pumps and such. It seems like those would be removed by the filter on the fluid return.

So it seems like the intake won't be removing much material. However, it will require the pump to pull harder to get a supply of fluid. This higher pressure lowers performance, and can cause cavitation (like in Hunt for the Red October). Finally, the tank is a fair bit more complex to build, because the current intake filter doesn't fit into the tank correctly.

Should this part be omitted entirely?

Baffling Design

Some hydraulic tanks are bisected my a baffle (info here). This baffle sits between the return and the intake. It's job is to force fluid travel the length of the tank. This causes it to mix and circulate before going back into the system. This helps with heat dissipation, lets sediment settle out, lets bubbles rise, and stops vortexes from forming between the surface of the fluid and the intake. Are these issues likely to manifest in the current design? Should a baffle be installed in the tank as protection?

Design for Maintenance

Some webpages suggest that hydraulic tanks have a drain plug on the bottom to make flushing out sediment easy. Should we put in one of these? Another suggestion is to have quick disconnects on the intake and return to make it easier to service the pump and such.

I think we can forego the disconnects because the tank is relatively small, and therefore easy to drain.

Design for Convenience

It might be helpful to have a window to see the level of the tank fluid. It might be helpful to have a thermometer to measure the operating temperature of the fluid. These seem like frills though-- how hard/expensive would they be to add?

Resources for Tank Design

General Tank Design - an advocate for painted interior, information on baffles

Some odds and ends for making tanks - Ever consider using a converted Keg (Aluminum, or Stainless Steel)?

Claim that Hydraulic intake filter can do harm.

Experienced Folk talking about practical tank design.

* Open & Closed questions updated