What is a Load Sensing Pump?

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Load Sensing Pumps are one of the most interesting subjects in industrial hydraulics. With just a few tweaks to a typical pressure compensator, you get a surprising improvement in efficiency and responsiveness. Today, we begin to explore how load sense works; in future videos, we'll go a whole lot deeper.
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Опубликовано:

3 авг 2024

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Комментарии : 76

@lastnameavailableok 7 лет назад

truly fantastic animations and explanations

@absalomachieshatumbu8235 6 лет назад

All this videos makes easier for me any time i am watching them thanks a lot

@steveh9106 7 лет назад

hi there, superb channel and great videos, you have helped me further understand hydraulics especially load sensing, i wish you had been around years ago, many thanks.

@Stutteringjohnfan2015 Год назад

Another great lesson from lightning McQueen!

@VanEugen 3 года назад

Класс! Спасибо за видео это очень полезно.

@ahmedmagdy179 5 лет назад

Thanks for the great videos, some thing make me confused so please can you help me to understand this two points 1- If the load sensing give the spring a boast to reach 600 PSI which equal to the pump output pressure so how the sliding spool take a appropriate displacement to maintain a required flow to the swashplate piston? 2- Also what the relationship between the minimum and maximum pressure output and the selection of the bias spring and the swashplate piston diameter?

@nicolasmaglasang5704 3 года назад

Great video i learned

@vinayakdeshpande4449 6 лет назад

Great video

@arslanahmad7000 6 лет назад

Thanks

@mikebeta1796 7 лет назад

how does these two valves react on a closed centre system with respect to pump flow and system pressure

@swatswapnil1 3 года назад

fantastic

@hedayatsadeghzade4335 9 месяцев назад

That's great ❤

@JesusMartinez-mi5oh 7 лет назад

Great videos, Carl. I appreciate that you take your time in giving of such as priceless knowledge. You explain in a great and easy to understand matter! Excuse me, I would thank you that you could confirm me if the load sense is the same as the pressure and flow control (DFR), like the A10V piston pump from Rexroth has. I get a little confuse in finding out if both, load sense and DFR, are refering to the same thing, please!

@lunchboxsessions 7 лет назад

Jesus Salvador thank you for your kinds comments. To answer your question, yes the Bosch Rexroth model DFR compensator is an example of this load sensing (flow compensating) pump in our video. Sauer Danfoss has the series 45 pumps with the same feature, and many others such as Eaton/Vickers and Parker have load sensing pumps that work in the very same way.

@JesusMartinez-mi5oh 7 лет назад

Carl, thank you very much for your support. I was having trouble with that, but you helped me. Your videos are impressive and well explained. You are making a great work!

@UniversalDiscovery 5 лет назад

💕

@ChandanKumar-ux3jz 8 месяцев назад

Very Good video sir ji

@gerardbergepaija4036 2 года назад

Hello Carl, I have a question. If I'm right, the piston speed is constant no matter the piston load is applied. To do so, we increase the presure of the pump in order to maintain the delta pressure and in consequence the flow. To do so, the LS is increasing the cm3 of the pump and this make me crazy. How it's possible that the LS increase the cm3 of the pump and the flow remains constant for a given pump speed? Does the pump maintains the speed? Thanks for all the videos. Really well done.

@cck1496 3 года назад

Excellent video, as you add bricks, the swash plate should also tilt more. Isn't it? Thanks.

@mechmancreations6147 6 лет назад

Sir, Can you provide a brief lecture about cartridge valves with animation.

@peterich5656 6 лет назад

Would a load-sensing pump serve any purpose on a system with large capacity accumulation? Wouldn't such a pump have to sense accumulator pressure instead of individual loads?

@GemmyHeart Год назад

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@MehediHasan-vz2pl 2 года назад

So beautiful

@myselfremade 5 лет назад

Hi Carl, excellent video series. If I have a directional control valve on my cylinder, such as say a hydraulic excavator, does that take the place of the needle valve, or is it positioned afterwards? Can decreasing the pressure drop across the needle valve increase system efficiency, or does it lead to instability?

@rahulahir7775 11 месяцев назад

I think that will control only - Flow / speed of actuator Or , Act as meter in / meter out circuit

@LowRafael 2 года назад

If I have a load sense pump, but dont use the load sense function i.e. plug the port, can the pump still work? or will I have zero flow out?

@ameen3399 3 года назад

How can understand either trouble in pump and lspc valve or main control valve?

@MrSaddam123456789 4 года назад

as the pressure increases how it is possible servo piston to increase swashplate angle I think as the pressure increases swashplate reduce its and flow rate

@shekarf 6 лет назад

Hydraulic power-packed getting trip due to low pressure when we operate cylinder on upward direction and we didn't understand that wts the problem

@pouicpouic47 6 лет назад

il y a une erreur sur votre schéma... le signal de charge ne communique pas avec le ressort de la valve de régulation de pression, mais seulement avec le ressort du LS

@AuroraClair 7 лет назад

What would happen if the load sensing spring would be set to 0?

@GMan-zn1uj 3 года назад

As bricks are added and removed we see the pump swash plate angle change (i.e. pump output/flow rate changes). How then does the flow rate remain constant through the needle valve while the pump output is fluctuating?

@benroberts6119 8 дней назад

I was wondering this. I think it's to account for extra leakage over the pistons at higher pressure. The pump has to account for that so there is a slight change in swash plate angle.

@BloominOnion1 6 лет назад

Here is where I am lost - in the video, the load pressure is brought about by stacked bricks (i.e, gravity induced load). What if I had a horizontal cylinder attached to a large mass? When I pressurize this horizontal cylinder, will it only see the 300 psi standby pressure since there is no gravity load to "backfeed" the circuit and make the pressure rise? I don't know how the system would ever produce high pressure under this scenario.

@lunchboxsessions 6 лет назад

In this case, to break away from a static state, there would likely be a short duration pressure build-up. Once moving, whatever the load pressure is at the cylinder would be added to the load sense (flow compensator) spring at the pump. The pump outlet (inlet to flow controlling valve) pressure would be the cylinder load pressure plus standby load sense spring setting.

@BloominOnion1 6 лет назад

Thank you very much! I appreciate your outstanding videos and explanations.

@prateepgowda3070 4 года назад

# you are showing in Delta P is constant, plz show this with proportional valve. With different opening the delta P is different and how it works with changing Delta P.

@SteveWrightNZ 5 лет назад

But if the needle valve was closed completely, would the pump limit on the pressure compensation setting? What is the proper way to set the speed - with the load compensation or the needle valve, or either? Thanks for teaching.

@ryanhawley7113 4 года назад

it would be via the needle valve. Speed isn't determined by pressure, therefore adjusting the pressure on the pump would not affect the speed, it would affect the lifting capacity. Speed is determined by the amount of flow getting the to the actuator within a certain time frame and in this instance, the needle valve is what determines the amount of fluid (flow) getting to the cylinder.

@fabwalk8133 7 лет назад

i'm a little confused here. the whole purpose of the load sensing system is to maintain a constant flow rate across the orifice right? that implies that flow rate is changing when ever the load is altered. but we already know that a piston pump gives a constant amount of flow rate at a given plate angle. so the flow rate across the throttle must be the same regardless of load fluctuations. i guess you see my predicament. please help me figure out what is missing :)

@lunchboxsessions 7 лет назад

Glad to help. Great question. Don't forget that as pump outlet pressure rises, the amount of internal pump leakage increases, and is seen on the case drain line, if a flow meter is present. Also, bulk modulus (compressibility of the fluid) means that very sudden increases in load (shock) pressure at the cylinder can cancel the pressure differential across the flow controlling valve, if only for a very short amount of time (perhaps less than one second), meaning that even a fixed swash plate angle cannot guarantee steady flow under all circumstances. Hope that helps a bit. Thanks - Carl

@fabwalk8133 7 лет назад

LunchBox Sessions that makes sense. And Really nice work and a great informative channel. Keep it up :)

@samerasaad7010 5 лет назад

@@lunchboxsessions So , what is the best margin value if we are surfing shock sudden load over very short time ? should we adjust margin to read low or high ?

@sathishr7774 4 года назад

@@lunchboxsessions can it happen if the prime mover (engine) lugs down (reduction in speed) because of increase in load . This reduction in speed causes reduced flow rates . when the engine governor compensates for it and sends more fuel to increase speed.This causes increased flow rate

@santiagodiazortiz8926 7 лет назад

hi, I'm a student from Colombia, im interested in doing a similar simulation like that, which program is that?

@lunchboxsessions 7 лет назад

We produce our simulations using software that our team built for our own in-house use.

@princerajpura7665 3 года назад

if load pressure is zero then l.s valve will be d stroke the pump? Lpm is zero?

@faridmahomed3339 7 лет назад

the pump compensator in excavator whtas sends the feedback the control valve or the cylinders??

@lunchboxsessions 7 лет назад

If the excavator has a load sensing system, the feedback sent to the pump controller ultimately comes from the load pressure at the cylinder. The most typical and convenient place to pick up or "sense" that pressure is just inside the directional valve, near the work port line that is connected to the cylinder. So while the feedback appears to be coming from the valve in terms of the hoses and lines, the pressure value sent is the cylinder load pressure. I hope that helps. Reply again if needed. - Carl

@romandragalev2366 2 года назад

What would happen to the pressure and flow if there would be no LS during adding and removing bricks? Wouldn't be the flow be the same since the swash plate is still at the same position?

@lemmyisgod9051 2 года назад

Would go to standby pressure

@joshclark6101 4 года назад

In a piece of equipment , do all the different loads/ cylinders have there own load sense lines

@teis79 3 года назад

Commonly, every manifold or valve bank has its own load sense feedback line. These are connected to the LS connection on the pump.

@ryanclarke2161 6 лет назад

Hey karl what are the wierd noises in the background? Im using head phones and a few of your vids have stra ge quite backgeound sounds.

@lunchboxsessions 6 лет назад

Hi Ryan. We used to put some quiet drone music in the background, since our microphone was really bad and we felt the music helped compensate for that. Since then we've upgraded our recording equipment, and no longer have the drone music - a huge improvement!

@BloominOnion1 6 лет назад

I actually liked the drone music

@Lucas.R753 4 года назад

How is the swash plate when no load but with engine running ?

@lunchboxsessions 4 года назад

The swash plate will be at a near zero angle, and hunting on-off to a very tiny on-stroke angle to produce only the low standby pressure as set on the load sensing (flow compensating adjustment) at the pump.

@mahmoudelsayed2016 5 лет назад

Hello Carl , why these videos are not included in the paid membership ?

@jayathbogahawatte6904 5 лет назад

The Coloring is different from what you have on the website. i think what's on the website is correct.

@lunchboxsessions 5 лет назад

We've updated this simulation since making the video here. We're constantly updating the content on our website ( lunchboxsessions.com ) - that's the benefit of being a member.

@ajitnayak2126 2 года назад

Hello sir, Myself Ajit Nayak from INDIA, I have Rexroth A10VSO100-DFLR-31R pump. before few days my team replace rotary kit in this pump. i request to you pl. guide me to set up Pressure, Flow control as well as load sensing valve optimum setting. my CNC machine required pre. is 3200 PSI, 50HP Motor using in this system. Thanks.

@Mech.Masters 6 лет назад

AFTER ADDING THE LOAD, HOW DID THE PRESSURE BEFORE THE NEEDLE VALVE, CHANGE FROM 600 PSI TO 900 PSI ? SETTING OF PRESSURE COMPENSATOR WAS AT 600 PSI INITIALLY, WITHOUT CHANGING THE PRESSURE COMPENSATOR SETTING TO 900 PSI HOW DID IT AUTOMATICALLY CHANGE AFTER ADDING LOAD HOW DOES THE PUMP ADJUSTS AUTOMATICALLY?

@lunchboxsessions 6 лет назад

Mech E , the pump adjusts automatically by adding the cylinder load pressure (right hand gauge) to the load sensing compensator on the pump. The load pressure is transmitted to the pump control using the LS signal line (the upper "L" shaped hose). The pump in this example already has a the load sense compensator set to 300 PSI using the adjustable spring force. I hope that helps a little.

@realstonge4326 7 лет назад

Do you have torque limiter animation,

@lunchboxsessions 7 лет назад

We have an older one that would need to be updated first. We'll keep it in mind.

@Mech.Masters 6 лет назад

SUPPOSE IF THE PRESSURE COMPENSATOR IS SET TO 200 BAR , WHEN PRESSURE IN GAUGE REACHES 200 BAR AND IF THE PUMP DOES NOT STOPS THE FLOW THEN WHAT WILL HAPPEN? WILL THE PRESSURE IN GAUGE RISE ABOVE 200 DUE TO CONTINUOS FLOW?

@lunchboxsessions 6 лет назад

Mech E if the pressure compensator (the left control valve and spring, also known as pressure cutoff PCO, or pressure override POR) is set to 200 Bar and the pump outlet pressure rises above that value, then we could say that the compensator is in fact NOT set to 200 Bar, or that the compensator has malfunctioned. Does that help?