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Open Source Ecology / Basic Theory / 26 Aug 2015
Open Source Ecology / Basic Theory / 26 Aug 2015
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From YouTube: Hydraulics Bulldozer - theory basics by Open Source Ecology

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Download the slides for the HYDRAULICS BULLDOZER: http://bit.ly/1WLBAro
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Hydraulic controls module. This is another Google document. You can first of all download the CAD by clicking the front page here and let's go through the hydraulic.

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The main concept here is that, in this implementation of hydraulic controls, the one piece of innovation was that we we made a circuit which allows you to run the tractor in parallel or series configurations in terms of the drive of the hydraulics, meaning parallel means that it's high torque low speed series configuration on through the wheel motors means that you have faster speed, lower torque, here's actual details- if you want to read through that about how that happens, to to do a complicated system which eventually ends up looking like this really messy situation here, we have to start with a benchtop prototype to test the hydraulic logic.

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So we we have a document part here. We show the actual bench top model. We started with this. We figure out what, when you hit the lever on the valves like we were exploring here: port, a port B in and out which, where does the fluid go? When you hit the lever so that for every component we can trace the fluid path here, the arrows are actually not shown. We could trace the fluid path for the entire system, so here in this example, for example, you can trace out okay.

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The black lines are the the parallel circuit. The blue lines are the series circuit. You can read the details, we have a set of requirements and the biggest one for the hydraulic design is its highly modular infinitely scalable and we actually are achieving that. You can plug in as many different hydraulic components as you like.

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As far as infinite scalability, you can actually add more and more power, cubes, there's a header that allows you to plug in as many power cubes as you like, there's another panel that has all the power going to the wheels through individual lines, so we're keeping everything clean while keeping it simple, quick couplers are used throughout.

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So basically, each quick coupler gives us twelve or fourteen gallons per minute. Each power cube is about fourteen gallons per minute, so a quick coupler pair is enough for one one power cube is an important consideration for just a general design. You have the power cubes in the back. You've got the cab module. How do you keep track of all the hoses, because the number is probably gonna be like 50 to 100 different hoses? It's a it's a big crow's nest of hoses.

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So what we have the power cubes are in the back here and what we're gonna do is run the power cubes, the hoses going up into a power cube, feed line which has separates all the power cubes neatly, and it goes down into a header which combines the fluid for the high flow through the hydraulic valves that we have, because altogether we have about 86 gallons per minute about a hundred sixty-eight horsepower of fluid power.

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So that's a lot of fluid and the interesting part here is that between the power cube feed the power cube panel here, where the power cubes come inside here, I just show one power cube, but we actually have six of them in between the power cube feed and the combining header.

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There are quick couplers, which means that you can put any single other device in there's gonna, be plenty of outlets, we're going to essentially have like six to twelve or as many as you like, plug-ins for powering any device like on the back of a tractor. You might have a few pairs of hydraulic, quick couplers. Here we have as many as we like, and that circuit feeds back into the header and runs the rest of the wheel.

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Drive the wheel drive is what really takes all the power in the traction application of a tractor, a bulldozer. You want all the power pretty much going to your wheels, we're doing so. Here's a bill of materials. You can actually get all these materials primarily from surplus Center. Here's a detailed bill of materials I go through different considerations here. How you make this circuit more and more complex to accommodate six power cubes? So here we have a basically a connection manifold with all the quick couplers conceptually going to all the different universal rotors.

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We have a check valve feeding from each power cube because you don't want back feed pressure. If say a power cube goes up because you can go between one and six power cubes. You can do that any amount of them that you like here's, some circuit diagrams control logic for the other circuits, and we also have another document you can link to that. The final product we we went through this can actual design. In this document.

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We actually went through this and refined it to a much much more accurate diagram, which you can look look at the links for that. The series two parallel conversion circuit for both scalable bulldozer drive. That's a definitely value added for open-source and that's about it. For the presentation on hydraulics. We can read through details and email us with any questions.