Closed Loop (Hydrostatic) Charge Pressure

Make sure you've watched our previous closed loop / hydrostatic videos (Part 1: • Closed Loop Systems - ... Part 2: • Closed Loop (Hydrostat... ). Now, we're going to go deep on the charge pump. What's it for? What are its flow paths? What pressure values can you expect to see it produce?
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[@michaelcostello6991]

Really great video. My lecturer would never be able to explain this like you have in this simulation. Amazing !!!

[@HauNguyen-tn3vn]

what happen when turn the swash plate from full angle to zero intermediately , the remain flow will pass through hot oil relief??

[@raminalikhani2262]

Hi there, I have a little problem with a hydraulic circuit, would you please help me,?

[@michaelcostello6991]

P.S. I have signed up at lunch box sessions website

[@GarranGossage-z2m]

I'm always blown away by the quality of your videos. Great content, explanations, and graphics. Keep up the good work!

[@samirboualem3547]

Please What could be the issue when a shuttle valve fluctuate between 200psi and 500 psi, for your information charge pump was adjusted 400psi and shuttle valve was adjusted 350psi, I had replaced shuttle valve but still the same issue, I have doubt maybe be one of 4 motors failed, what do you think?

[@johneduardolaborem1]

Goodnight. excuse my English. It is not my language I have a caterpillar crawler loader. Its transmission is hydrostatic. Inside it uses two piston pumps. Which are driven by two hydraulic cylinders that move the oscillating plates. This transmission carries a load sensing system, which works directly with the engine revolutions. Has pilot valve, servos, main control valve etc. Has several points of pressure. One of them is called charge pressure. Is actually a pilot pressure. When I activate the pumps with the machine stopped, brakes on. This pressure does not just fall. But also that it oscillates. The manual tells me it can not fall to less than 100 psi. And falls. But it rises again and falls again. The manual tells me that an indication is possible that there is excess leakage inside the piston pump. The fault is progressive, it gets worse and worse as the oil heats up. my question is. If there is leakage inside the pump, should not it fall and stay there? Bone should not rise again, then fall. Or will I miss any adjustments? Thanks here I leave the link kzbin.info/www/bejne/mpK4p3evq7Kto8k. The hydraulic scheme is very similar to this. I believe that leaks break the bonds in unity. I want to add that the traction motors have no leakage since they block them, and the fault continues. Then, in a few words. My question is simple. A low load pressure is indicative of a leak in the main pumps? Is this why when I turn the lever fnr to max foward the oscillating plates come in and out? The load pump is gears and was tested on a bench and that's fine. I leave another link for you to see part of the system. Is very similar to the one you speak. Thank you. Https://kzbin.info/www/bejne/aKKalJ-InbqCp9k

[@arifindwi6121]

Hi, what if the pressure is unstable when the motor is off? It should be stable at 300 right? But it always drop to 260 every 3 seconds. Thanks.

[@Mikemrs781]

Why is the tank line in blue passing through the msin pump again on its way to the tank?

[@sammy-me4xn]

Bcoz its a closed loop circuit or else each pump rotation has to suck fresh oil from tank, as there is pump leakage and also pump case drain (not shown ) some hot oil passed off and cold oil is replenished by charge pump

[@harrisonfowler4461]

I have a video on my channel of my charge pump on a garden tractor. Could you take a look and tell me if it sounds like it's cavitating? I think it is, but I'm not 100%. I am certain that the noise is coming from the charge pump. I've never heard it before.

[@Joscope]

Is the best place to filter and cool the oil the outlet of the charge pump?

[@JP-hk7qs]

I have little problem with Hydrostatic pump please can i get help

[@garymatusavige3639]

Ok on a eaton 70144 would I tee the charge line to get pressure reading

[@jcolivera881]

Is the Eaton motor ran off of charge pressure?

[@garymatusavige3639]

@@jcolivera881 not sure mine is still working

[@pradachannel7940]

how to decrease motor rpm?

[@RailFan92]

Great video, very useful thanks

[@thunderbirdbob1]

I have a eaton 70145 lal pump with a charge pump. your video helped me understand it a little bit better but not completely. could someone contact me to help me out?

[@thunderbirdbob1]

LunchBox Sessions ok I just took a look at your part 1 I think I understand now. if I do have any more questions I will contact you thank you vary much. if you check out my video my most recent one shows you what I'm doing. if you have any suggestions please let me know. thanks bob

[@رافضيحب]

How can I get this program

[@NorAlb_Chainsaw_Carver]

How is it possible that the charge pump can open the check valve at 260psi yet fails to open it at 300psi when it's going over relief?

[@diegoortiz1012]

I think that it opens the check valve at 300 psi, but just for a brief moment: as son as the swash plate is centered, oil might flow long enough to put pressure right after the check valve, but once both pressures are 300 psi, oil can't keep flowing through either check valve and it goes through the charge pump relief valve.

[@simclardy1]

The pressures balance on both sides if the check valve so no flow.

[@ustarecepusta]

Teşekkür

[@vivekpandey841]

What advantage close circuit

[@archaosy]

Why not redirect the Hot Oil Shuttle directly to the motor to cool it down? The pump already gets cooled oil from the charge pump, while I think the motor could overheat this way. Am I wrong? Nice video still thx!

[@lunchboxsessions]

You are correct that sometimes the output from the hot oil shuttle is directed through the motor case. On a motor with two case ports, one for flushing-in and one for draining-out, this is then called a full flushing loop. Help with cleaning away contaminants and wear particles, and can help a little bit with heat. Many motors in closed loop, hydrostatic systems now self-flush using a small amount of the main loop, inlet flow and then draining back to tank on a single case drain line. Great question, thanks for writing. - Carl

[@archaosy]

Thank you very much for the answer. Much appreciated!

[@jcolivera881]

LunchBox Sessions this is the case an a lot of poclain driven self propelled equipment!

[@shibaramreddy1874]

Accumulator charging system

[@jovanni_orb5116]

yes

[@rajarao1200]

Super

[@jovanni_orb5116]

helpful

[@OriginalAyron]

What would cause a huge drop in charge pressure when the main pump is in full displacement. The identical pumps drop from 350 to 300 and the faulty one drops to 150

[@JP-hk7qs]

I have the same problem did u solve that

[@OriginalAyron]

@@JP-hk7qs turns out it was bypassing in the motor which had a failed piston. You could visually see the motor slowdown/stop at a certain point during the revolution

[@jcolivera881]

I was going to say check your case drain flow on whatever those pumps were running.

[@islamtaha6414]

You are My teacher

[@andibachrul5942]

Amazing

[@vivekpandey841]

Nice

[@workwillfreeyou]

So the main pump case has up 300psi?