Front-End Loader Comfort Ride

[ptsg]

I'll go as far as saying that maybe 90% of the soft rides systems out there uses the bladder type accumulator with great success and I haven't heard of any issues at all.

I bought it at the scrapyard a long time ago. It came with other hydraulic stuff I was looking for. This was over 18 years ago, so who knows how older the thing is. Sometime ago, I found the accumulator and much to my surprise it was still charged and working great.

Mine is charged with about 725 PSI, which I found to be a little too much for an empty bucket or forks. It's mostly effective with a full bucket or something on the forks. Still, very nice to have and it's night and day difference on comfort. The ones I've seen for sale are charged anywhere from 435 PSI to 600 PSI.

 

[jonsstihl]

thanks for the update, to me that seems a little low a charge setting since as soon as your system PSI reaches 600PSI you have no more damping and your accumulator is bottomed out. that leaves a lot of PSI range example 600psi-2630psi for my system with a bottomed out accumulator.

maybe I am thinking about it backwards because if my charge pressure was 2630psi there would effectively never be any damping since the system pressure never exceeds the charge pressure.

there is not much info out there on the web about accumulators in this (static) shock absorption application.

 

[npalen]

Interesting discussion!

Wonder if anyone has tried gas shock lift cylinder connections to cushion. Probably wouldn't work, just a thought.

It would be interesting to experiment with accumulators for the FEL as well as the 3PH top link cylinder to see if the "empty ride" could be improved. My Mahindra 3015 with industrial tires rides like a lumber wagon when roading, in fact its more like "rodeoing". Could the accumulators act like spring suspension on a vehicle in this situation? Sounds like the accumulator system would, somehow, need to be variable pressure. Perhaps two sets of accumulators, one for loading and one for roading?

 

[jonsstihl]

thats kind of what the WR Long system is atleast on the loader. they have one accumulator that is charged based on the empty setting and one that is charged based on the loaded set up so you get more even shock absorption across the entire load range of the loader. I've never seen two accumulators on the 3pt hitch though.

the accumulators I have seen are actually on the three point lift system but I suppose if you really wanted to you could put them on the 3pt lift, loader and top link

apparently they really make a night and day difference especially in roading applications, thats why I really want to get this setup going. i'm tired of the loader banging around on my trails.

 

[Smokeydog]

Agreed bush hogging with a loader and during the transport of materials the harshness of the loader over bumpy terrain is greatly reduced. A system benefits that are felt more than seen. With a gauge on the loader lift circuit can see a significant decrease in pressure spikes when carrying a load. Simple system.

Don’t think a 600psi bladder is bottomed out at 600# or 600psi loader pressure. Doubt if bottomed out at 4000psi+ loader pressure but cushion volume would be reduced. With lift, curl and wheel traction forces have had loader lift pressure approach 5,000psi.

The Kubota Soft Ride (KSR) system is a two bulb accumulators with different pressures. Don’t know if two bulbs at different pressures was to increase damping range? Decrease pogo stick hysteresis in a closed system? Or simply to utilize off the shelf components that kinda meet requirements and fit the tractors limited space? Could be none or all three.

I installed hard tip needle valve in addition to a ball valve between accumulators and tractor loader. Two reasons. If I needed flow control and 2nd, needed another 2-3 inches of piping to ergonomically position the ball valve. Had the hydraulic fittings but not the nipple on hand. Turns out I have seen no reason to have a flow control valve.

 

[jonsstihl]

Do you know what pressures yours are set at or did them come already pre charged. If I remember correctly you got yours off of ebay right.

 

[Smokeydog]

280psi and 580psi precharged. Bought the whole KSR kit off eBay. Only used the accumulators, some fittings and one bracket. Several brackets, hoses, hardline and valve I didn’t use.

Used a digital 10,000psi gauge. Nice, accurate, can tare, change scales, zero and back lighting. Likes to eat batteries. Has option for usb. Handy for my primary testing but now may switch to a simple 6,000 psi mechanical gauge like NoShok. Fun to monitor loader pressure when using a KSR system

 

[jonsstihl]

and what is your loader capacity and max system pressure so I can more accurately guesstimate my required charge pressures

thank you

 

[rScotty]

It's interesting to follow along here. We have "comfort ride" on the yellow JD. It is very nice anytime on the road - and especially so when carrying bucket loads over a couple of tons.

Bought one for the Kubota a year or so ago from Kubota overstock on Ebay. Not installed yet. I rarely road the M59 - but use it daily.

FEL geometry counts for as much as system psi. Most tractors today are capable of 2800 to 3000 psi, but I rarely see half that on the pressure gauge. And a lot of work is done under 1000 psi.

 

[jonsstihl]

I've maxed out my FEL a few times moving stacks of lumber for a deck and more recently pallets of stone for a walkway that I had to take a few off to get them to lift. But my tractor is not an M59. This is not really scientific but I'm thinking of comparing max system pressure to charge pressure to determine a good setting but I don't even know if the relationship is linear and I'm assuming the type of accumulator would affect the settings as well.

I have a request for quote out for several different type of accumulators. would be nice to have one that is rebuildable but if it is three times the price I will bet on the non rebuildable one since I need two for the loader and one for the 3pt hitch.

 

[rScotty]

I've maxed out my FEL a few times moving stacks of lumber for a deck and more recently pallets of stone for a walkway that I had to take a few off to get them to lift. But my tractor is not an M59. This is not really scientific but I'm thinking of comparing max system pressure to charge pressure to determine a good setting but I don't even know if the relationship is linear and I'm assuming the type of accumulator would affect the settings as well.

I have a request for quote out for several different type of accumulators. would be nice to have one that is rebuildable but if it is three times the price I will bet on the non rebuildable one since I need two for the loader and one for the 3pt hitch.

Being a little bit scientific can save a lot of time. I'm know I'm just following along here, but if you are going to compare max system pressure, it will help to know how system pressure relates to the load in the bucket.

In your workshop manual there will be a table of loader lift versus height that will give you a feel for that relationship. It varies with lifter geometry; I'll copy one such below. By solving triangles and roughly approximating the cylinder surface area you can solve for pressure required to do that lift, and the graphed numbers can be used to check your figures.

I think what you will find is that working stationary pressures are not only lower than max, but often far lower. And you can see immediately that geometery has a huge effect. When the loader arms and cylinders are closer to parallel it takes a lot of hydraulic pressure to raise the arms at all.

Road bounce creates pressure spikes that are much higher and faster than the tractor pump's hyraulic system pressures. Measuring them with a fast-reading pressure gauge is far easier than calculating those little monsters. Remember, you are only trying to damp them... not eliminate them. The energy stays the same in the system; the idea is to spread it out over a longer period of time. Make it less abrupt.
luck, rScotty

 

[jonsstihl]

thanks for the extra info. it is much appreciate. my chart is actually in the loader manual and I just pulled it out this week to see if I could lift my pallets of stone. my lift capacity at ground level is around 3300 lbs which i'm assuming is at max system pressure but I understand what you are saying. is the TL1350 the M59 loader. Close to 50% more capacity than my LA854

those charts are max capacities at max system pressure. but I agree most of the time we are not maxing out the system. I have my tee actually installed in the system and capped. I just need to find the time to hook a gauge to it and measure system pressure with an empty bucket and with a loaded bucket.

 

[Smokeydog]

From little tractors to big tractors the pressure of hydraulic systems are about the same. What changes is surface area of the cylinders vs load and the volume of oil of the hydraulic pumps. The accumulators dampen by variable volume displacement changing their pressure from reaction to hydraulic pressure. Being able to displace adequate volume is more important than the pressure. Thumb size accumulator help you?probably not. Basket ball size? Probably too much give.

The two bulb McCormick accumulator system has two bulbs the same pressure for a smaller tractor.

Dolllars to donuts the manufacturers geniuses spent less time calculating than trying similar options to see what worked the cheapest.

Keep it simple. Have fun.

 

[npalen]

Do variable restrictors (flow control valves) have a place when plumbed in series with accumulators? Perhaps restricted in one direction (up) only?

 

[oldnslo]

Do variable restrictors (flow control valves) have a place when plumbed in series with accumulators? Perhaps restricted in one direction (up) only?

Flow controls or orifices can and are used to fine tune ride control. Free flow into the accumulator and meter out. This reduces or eliminates the pogo stick potential. Accumulator absorbs the spike and then slowly puts flow back into the circuit.

 

[npalen]

Walterscheid GmbH | NEW – hydraulic top link with shock absorber

Top links - NEW – hydraulic top link with shock absorber. Walterscheid GmbH

www.walterscheid.com

Ran across this as a first, for me at least, and thought it would be somewhat pertinent to this discussion on loader cushioning.

 

[Smokeydog]

Walterscheid GmbH | NEW – hydraulic top link with shock absorber

Top links - NEW – hydraulic top link with shock absorber. Walterscheid GmbH

www.walterscheid.com

Ran across this as a first, for me at least, and thought it would be somewhat pertinent to this discussion on loader cushioning.

Agree about the added traction from cushioning heavy loads on soft ground with a FEL.

Like to see a cat1/2 cushion top link. Might not be too hard to make or some how tie into the accumulator system when needed.

 

[jonsstihl]

Just got my pressure gauges hooked up on the loader and the three point hitch circuits. 3pt hitch hose is bspp #6 so I went with a T on the left side but you have to watch the linkages. atleast there is more room than the right side with the remote valves and linkages

loader stalls at 2400 psi
empty is at 500 psi
empty bucket 700
bucket full of wet dirt 1200psi
grapple 800
empty forks 600

3pt hitch
quick hitch is 100psi
my custom counterweight is 500psi
72 inch flaifl mower 500 psi
snow blower (weights 1200lbs) is at 900 psi

talked to a guy last week from a hydraulic place and he sounded really knowledgeable and was a reference from the multiple other places I tried.

 

[rScotty]

SNIP

Dolllars to donuts the manufacturers geniuses spent less time calculating than trying similar options to see what worked the cheapest.

Keep it simple. Have fun.

Are you saying that they try similar options by actually making a FEL and trying it? Or by modeling one on a CAD program?

If it's physically making one up - which I kind doubt these days - but if so I'll take that bet, and hope someday to collect.
It seems to me that there is no cheaper way to design than in CAD. Way less expensive than fabricating and testing.

What is surprising me is not yet seeing ads from people selling completed model files of common mechanical designs. It seems like a reasonable type of business. As an example, using a dynamic model file of something like our M59 FEL makes designing a new style of bucket much easier.
There are a number of makers of specialty attachments for tractors. I wonder what would be a fair price for a working model file like that? Or is every company making their own?
rScotty

Make mine donuts.

 

[rScotty]

Just got my pressure gauges hooked up on the loader and the three point hitch circuits. 3pt hitch hose is bspp #6 so I went with a T on the left side but you have to watch the linkages. atleast there is more room than the right side with the remote valves and linkages

loader stalls at 2400 psi
empty is at 500 psi
empty bucket 700
bucket full of wet dirt 1200psi
grapple 800
empty forks 600

3pt hitch
quick hitch is 100psi
my custom counterweight is 500psi
72 inch flaifl mower 500 psi
snow blower (weights 1200lbs) is at 900 psi

talked to a guy last week from a hydraulic place and he sounded really knowledgeable and was a reference from the multiple other places I tried.

Wonderful info! Were you as surprised as I was at how low the actual pressures are when lifting a load?

It's odd how many Japanese makers use British Standard threads - tapered and parallel both - for fluid connections in their otherwise metric world. I wonder how that happened.

rScotty