Setting suspension accumulator pressures for the perfect ride.

[davidroberts30]

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[Xiaomi]

That’s correct. So if the pressure in the ram was 40 bar the system would ride best with an accumulator preset at 20 bar.

I'm going to add softride to my loader. I appreciate you're talking about tractor suspension, but I'm assuming that the principle behind a loader setup is similar. From reading your posts I do the following:

1. Measure pressure at ram with empty loader
2. Measure pressure at ram with full loader (round bale on)
3. Accumulator 1 set to half of pressure measured in step 1
4. Accumulator 2 set to half of pressure measured in step 2

Easy as that?

What is the compression ratio of your accumulators? I assume that it is greater that 5:1 so that your 30Bar accumulator doesn't max out under a full loader.
Did you measure the pressures under static or dynamic conditions?

 

[Colliedog]

I'm going to add softride to my loader. I appreciate you're talking about tractor suspension, but I'm assuming that the principle behind a loader setup is similar. From reading your posts I do the following:

1. Measure pressure at ram with empty loader
2. Measure pressure at ram with full loader (round bale on)
3. Accumulator 1 set to half of pressure measured in step 1
4. Accumulator 2 set to half of pressure measured in step 2

Easy as that?

What is the compression ratio of your accumulators? I assume that it is greater that 5:1 so that your 30Bar accumulator doesn't max out under a full loader.
Did you measure the pressures under static or dynamic conditions?

That’s the basic principles of installing accumulators. However loader Softride is a bit of a controversial one due to the extreme pressures variations they deal with. Most loader Softrides have a 10 & a 20 bar accumulator and sometimes a further 10 on the rod side of the ram. Which guess would work well for no load and light loads found in most operating conditions. But like you mentioned accumulators have a compression ratio, good quality ones being 8:1 which still brings the minimum pressure to be 26 bar on a 210bar system, which would appear to be too high. My suggestion would be to do what’s proven but turn the Softride off for heavy loads. The accumulator sizes tend to be around 0.5ltr or slightly smaller for smaller loaders.

 

[Frankzy]

I'm going to add softride to my loader. I appreciate you're talking about tractor suspension, but I'm assuming that the principle behind a loader setup is similar. From reading your posts I do the following:

1. Measure pressure at ram with empty loader
2. Measure pressure at ram with full loader (round bale on)
3. Accumulator 1 set to half of pressure measured in step 1
4. Accumulator 2 set to half of pressure measured in step 2

Easy as that?

What is the compression ratio of your accumulators? I assume that it is greater that 5:1 so that your 30Bar accumulator doesn't max out under a full loader.
Did you measure the pressures under static or dynamic conditions?

That’s the basic principles of installing accumulators. However loader Softride is a bit of a controversial one due to the extreme pressures variations they deal with. Most loader Softrides have a 10 & a 20 bar accumulator and sometimes a further 10 on the rod side of the ram. Which guess would work well for no load and light loads found in most operating conditions. But like you mentioned accumulators have a compression ratio, good quality ones being 8:1 which still brings the minimum pressure to be 26 bar on a 210bar system, which would appear to be too high. My suggestion would be to do what’s proven but turn the Softride off for heavy loads. The accumulator sizes tend to be around 0.5ltr or slightly smaller for smaller loaders.

If I remember correctly the Volvo L70 we have uses one at 20 bar and one at 40.
Around 1,5 litres maybe?

 

[Xiaomi]

Thanks - the main problem I have is travelling empty along back roads as I'm flung about and the loader itself crashes and bangs.
I had thought that it wouldn't be too difficult to put on an additional accumulator for when it is loaded with a round bale of silage.
Plan was to tap into the circuit and connect a pressure gauge to see what pressure an empty loader and one loaded with a round bale would be. From that I could determine what pre-charge to get put in the accumulators. Then just plumb it in with a tap to isolate.


My understanding of the precharge etc, was that precharge (P0) was only related to your max working pressure (P2):

So take this example Accumulator 0.35L:

Maximum preload: 210 Bar.

Body: made in painted carbon steel.

Working temperature: from -20ºC to +90ºC.

Compression ratio: recommended: P2/P0=2.5; maximum: P2/P0=6.

According to: 97/23/CE-PED; 94/9/CE-ATEX Group II Cat 2; GOST-R; SELO-CSEI.

Standard nitrogen valve: 5/8” UNF.

Standard nitrogen preload: 150 bar.

If you set your precharge, P0 to 10 Bar, then the max pressure (P2) for the unit is 60 Bar, ideally 25 Bar. If your second accumulator was precharged to 20 Bar, then max pressure is 120 Bar, ideally 50 Bar. Correct???

What I don't understand about the dual accumulator setup is how does loaded pressure not adversely affect the accumulator for the empty loader. Would it not squeeze this accumulator to its limit before the one for a loaded loader started to take effect?
I guess I may just take some measurements and see where it takes me to.


In regards to the tap, I just can't see those using it remembering or bothering to turn it off when putting on a heavy load.

 

[Colliedog]

In an ideal world. Accumulators shouldn’t be put out of there operation ratio but in many situations manufacturers use them like this. I think in your situation putting a gauge on is going clarify what you are doing is correct. You can get them quite cheaply from flow fit on line complete with a microbore pipe.
The two factors to remember are gas compresses at a ratio of roughly 2:1 so basically if a 1tr accumulator with 10 bar pre charge pressure is compressed with 20bar oil pressure the diaphragm will be sat in the middle of 0.5 ltr of oil and 0.5 litre of gas both at 20 bar pressure and so on.
Secondly big accumulators with higher pressures will give more float on the loader. A good thing for ride quality on the road. However this will make using the loader more difficult as the accumulators will need to be filled before the loader reacts when lifting loads.

 

[joseluis97]

buenos dias tengo una caja puma 240 del año 2020 sistema activo dual acumulador creo precargado de fabrica a 32bar y el grande 2lt a 54bar , pero cuando el tractor no tiene lastre delantero la suspension casi no funciona , esto ha pasado alguna vez desde. la mejor manera de hacerlo es con un lastre delantero de 800 kg y un peso trasero. Me pregunto si se podría añadir un acumulador de menos barra 25bar por ejemplo para mejorar la suspensión y poder ir sin lastre delantero. gracias

 

[davidroberts30]

buenos dias tengo una caja puma 240 del año 2020 sistema activo dual acumulador creo precargado de fabrica a 32bar y el grande 2lt a 54bar , pero cuando el tractor no tiene lastre delantero la suspension casi no funciona , esto ha pasado alguna vez desde. la mejor manera de hacerlo es con un lastre delantero de 800 kg y un peso trasero. Me pregunto si se podría añadir un acumulador de menos barra 25bar por ejemplo para mejorar la suspensión y poder ir sin lastre delantero. gracias

get your accumulators checked for actual pressure, you could try lowering the pressures by 10bar?

 

[mf7480]

@Colliedog i’m sure there’s an opportunity here to put together an off the shelf kit for retail. Most people wouldn’t want the hassle of buying the nitrogen kits and parts individually, then setting it all up to the correct pressures but if you could supply a box of parts ready to go ready setup for each model, that just needed bolting on with a set of spanners I bet you’d sell a few. It’s got to be worth £500 of anyone’s money going by that gopro footage.
The cab suspension upgrade is probably a greyer area with type approvals and safety ratings to contend with but the beauty of the axle suspension upgrade is you haven’t actually changed any of the mechanical links.

@Colliedog can I have some commission

I jest, looks like you’ve made a great business of it, seems to be most of the main dealers are offering the kits?

 

[joseluis97]

haga que sus acumuladores revisen la presion real, ¿podría intentar reducir las presiones en

Hola En el concesionario revisaron las presiones hace un año, estaban correctas, pero había bastante presión en el acumulador por la válvula de arriba, sin mejoría alguna.
Envié algunas imágenes de los acumuladores, podría intentar quitarlos nuevamente, pero ¿dónde puedo quitar la presión?
thanks.

 

[cosmagedon]

I've not got any experience on the newer setup, I'm assuming that's sky hook? 1 accumulator for each side of the suspension ram?

If that's the case the big one would be better around 30 bar, then adjust the settings on the armrest if you carry more weight on the front.

 

[joseluis97]

hola Sí, es el sistema skyhook. El acumulador grande de 2 litros trabaja a 54bar, por lo que podrías instalar un tercero con un bypass del mismo, para poner un tercer acumulador de unos 30bar por ejemplo.

 

[Colliedog]

@joseluis97 The accumulators for this model should be 32 bar this is the optimal pressure for this model. I guess if there is more it’s for one of two reasons. Either you are testing the accumulators without removing them from the tractor? This will read the hydraulic pressure in the closed side of the system, or someone has over charged them. Either way they need to be removed and checked assuming your gauge is accurate.
I assume you know the suspension on Lwb tractors is adjustable between soft, medium and hard? It’s surprising how many people drive them without realising.
The front suspension system on Lwb tractors works reasonably well if everything is in rude health.

 

[Colliedog]

@Colliedog can I have some commission

I jest, looks like you’ve made a great business of it, seems to be most of the main dealers are offering the kits?

It’s certainly been a journey since the first post! The front suspension kits sell slowly as they only fit tractors up to 2015 model years. However the air suspension is going very well with lots going onto new tractors until the new cab with semi active suspension is available.
There was a lot of work, stress and development to get here though!

 

[joseluis97]

@joseluis97 Los acumuladores para este modelo deben ser de 32 bar esta es la presión óptima para este modelo. Supongo que si hay más es por una de dos razones. ¿Está probando los acumuladores sin quitarlos del tractor? Esto leerá la presión hidráulica en el lado cerrado del sistema, o alguien los ha sobrecargado. De cualquier manera, deben eliminarse y verificarse, suponiendo que su calibre sea preciso.
Supongo que sabe que la suspensión de los tractores Lwb se puede ajustar entre blanda, media y dura. Es sorprendente cuántas personas los conducen sin darse cuenta.
El sistema de suspensión delantera de los tractores Lwb funciona razonablemente bien si todo está en perfecto estado de salud.

El revendedor las revisó, y la pequeña viene de fábrica a 32bar, la grande a 54bar, las sacaron y revisaron. Siempre lo tengo en modo suave, sin embargo, voy a comprar el kit de suspensión de aire de cabina que vendes. gracias

 

[hoyboy]

@joseluis97 The accumulators for this model should be 32 bar this is the optimal pressure for this model. I guess if there is more it’s for one of two reasons. Either you are testing the accumulators without removing them from the tractor? This will read the hydraulic pressure in the closed side of the system, or someone has over charged them. Either way they need to be removed and checked assuming your gauge is accurate.
I assume you know the suspension on Lwb tractors is adjustable between soft, medium and hard? It’s surprising how many people drive them without realising.
The front suspension system on Lwb tractors works reasonably well if everything is in rude health.

I didn't know the suspension is adjustable. How do you adjust it on a cvx 225?

 

[joseluis97]

No sabía que la suspensión es ajustable. Como se ajusta en una cvx 225?

La suspensión se ajusta manteniendo presionado el botón del panel ICP de bloqueo de suspensión durante varios segundos, y se puede ajustar en tres posiciones, pero creo que solo funciona en acumuladores duales.

 

[del_boy]

I didn't know the suspension is adjustable. How do you adjust it on a cvx 225?

Not sure on the case but on the lwb nh hold the front suspension button for a few seconds, the screen in the dash will then show which mode its in, press the suspension button again to toggle between soft, normal and hard

 

[Blue.]

I didn't know the suspension is adjustable. How do you adjust it on a cvx 225?

Press and hold the suspension button on the keypad,you can toggle through soft med and hard.

 

[Drillman]

Not sure on the case but on the lwb nh hold the front suspension button for a few seconds, the screen in the dash will then show which mode its in, press the suspension button again to toggle between soft, normal and hard

Press and hold the suspension button on the keypad,you can toggle through soft med and hard.

Does anyone ever put it into anything other than soft?