Outer Limits 4x4 Board

Ok this has been debated quite a few times, but my searching hasn't given me the answers I am looking for.

I have just gotten myself a hydraulic winch which comes set up to run of the PS pump. However a quick look at the PS flows and the motor ratings shows that it will be a slow winching exercise. I am not after comp speeds, or to increase the pressure, but around the 30+ l/m will give a good standard winching speed.

I have considered the option of adding a dedicated pump to the GU, however there is limited space in the engine bay and before I start pulling my hair out making a pump fit I want to look at replacing the power steering pump.

The specs on the motor on the winch are:

• 50 ml/r
  20-50L/m
  8.5mpa (14mpa max)

Here are the two options that I am looking at:

1) Replace the power steering pump with a higher volume unit (60l/m) and then run the winch and PS in parallel.

2) Replace the power steering pump with a unit containing two separate pumps, the first runs the PS with approx. 8-10l/m flow, and the second would flow up to 50l/m only for the winch with an incorporated by-pass valve for general driving so there is no pressure in the system, just oil circulating.

For both options a remote resivour would be incorporated, and oil cooler in series with the winch hydraulics.

- David.

I would run off the existing pump. Failing that, I would install a pump with more grunt. I wouldn't run a second pump for this, just because I think upgrading the pump will produce a satisfactory result with less work.

I wonder if it is worth looking at just putting a bigger pulley on the existing pump so it runs at higher rpm. Not sure, might be worth looking at, maybe add a cooler at the same time on account of the pump working harder.

chimpboy wrote:........................
I wonder if it is worth looking at just putting a bigger pulley on the existing pump so it runs at higher rpm. Not sure, might be worth looking at, maybe add a cooler at the same time on account of the pump working harder.

A bigger pulley on the pump will slow it down. A smaller pulley will speed it up.
A cooler with a little fan on it is a good idea... Lots of bikes have nice little thermo fans and are cheap from wreckers.
Jas.

want33s wrote:

chimpboy wrote:........................
I wonder if it is worth looking at just putting a bigger pulley on the existing pump so it runs at higher rpm. Not sure, might be worth looking at, maybe add a cooler at the same time on account of the pump working harder.

A bigger pulley on the pump will slow it down. A smaller pulley will speed it up.

Errrr.... that's what I meant, honest

Not sure what you mean by a bypass valve?

Remember PS (hydraulic) pumps are positive displacement - x cc/rev.
You can't reduce the flow, it's fixed, no matter the load.
Normally it goes round and round with little drag.
When you steer, it restricts the flow and makes it do some work.
When you hit the steerin stop, it can't do teh work, no matter how hard it tries, and the pressure climbs until the releif valve opens in the pump.

BUT

If you try shoving more oil, through the orifice in your PS Box, sooner or later it won't all fit. Pressures will climb at higher RPM, oil will get hotter as now working all the time etc.

I would be interested in seeing what you come up with.

There are also variable displacement hydraulic pumps, and all sorts of interesting stuff I haven't managed to understand yet. Think how hydraulic machinery gets several things to work at once - how does that work? Parallel circuits with a single pump. But that means there must be pressure on those all the time, unlike P/S where there is only pressure whilst steering. And they would chew a heap of fuel and get mega hot when doing nothing, so there must be a bypass for no-load. Poor head - hurts.

Personally I reckon there are 4 real choices

1. PTO Hydraulic Pump - if you car has it (mine doesn't)
2. Use the PS pump, and deal with the speed
3. A Second Pump just for winching - will cost weight / space / fuel though. What's the max power for a V Belt?
4. A really tricky twin parallel pump system with a bypass or clutch and I'm not sure what valve system. That would take some thinking. This particualr invention may not exist, may make me rich if I patent it, or may violate the laws of physics. One pump normally for steering, 2 pumps in parallel for winching.

OneMadEngineer has some info on pressures / flows etc.

If you winch is a Milemarker / Ox - check out the articles on the restrictors in the valve body, and the alternate valve bodies. There is also braking to consider - they brake using the oil, not a brake (or so I believe).

Runva does a chinese hydraulic winch, but I have no real info on it other than it exists.
Ironman was supposed to be experimenting - but again - heard nothing more.

Paul

chimpboy wrote:I would run off the existing pump. Failing that, I would install a pump with more grunt. I wouldn't run a second pump for this, just because I think upgrading the pump will produce a satisfactory result with less work.

I wonder if it is worth looking at just putting a bigger pulley on the existing pump so it runs at higher rpm. Not sure, might be worth looking at, maybe add a cooler at the same time on account of the pump working harder.

So that is one vote for the use of a larger (spin the shit outa standard) pump and run it all in parallel.

Paul,

The bit I think that is missing is that even though there is no need for fluid into power steering pump, this unwanted oil is exhausted pass the pressure relief valve. As without this restriction no pressure will build up. This restriction therefore results in power required at the pump to build enough pressure to open this valve.

The bypass valve that I am talking about would remove this from the circuit. Effectively making the pump a transfer pump rather than a pressure pump.

I grabbed one of the Runva's from Diecrest. The specs for the winch are on the Runva website of you are interested. http://www.jhrn.net or http://www.runva.com

- David.

Dirty wrote:Paul,

The bit I think that is missing is that even though there is no need for fluid into power steering pump, this unwanted oil is exhausted pass the pressure relief valve. As without this restriction no pressure will build up. This restriction therefore results in power required at the pump to build enough pressure to open this valve.

The bypass valve that I am talking about would remove this from the circuit. Effectively making the pump a transfer pump rather than a pressure pump.

I grabbed one of the Runva's from Diecrest. The specs for the winch are on the Runva website of you are interested. http://www.jhrn.net or http://www.runva.com

- David.

Nup - my brain failed on that one.
Can you draw a diagram?

Thx
Paul

Paul,

Maybe spend more time working on your shit alloy winch setup than commenting on this shit, get out in the shed and get to work.

Ben

Evil 73 wrote:Paul,

Maybe spend more time working on your shit alloy winch setup than commenting on this shit, get out in the shed and get to work.

Ben

What the? He experimented with something new... It was not well recieved but that does not mean he doesnt know what hes on about. his posts involved thought and knowledge and were relevent to the question.

yours was useless.

so is mine

me3@neuralfibre.com wrote:
Nup - my brain failed on that one.
Can you draw a diagram?

Paul

Within a hydraulic system there needs to be a pressure release valve which controls the maximum pressure created by the pump. In the case of the power steering when not moving the wheel, there is no need for any fluid supply to the steering box, so all fluid is exhausted though the pressure release back into the resivor. As without the pressure release valve fluid pressure would keep climbing until either the pump stalled or a pipe/seal burst. So even when the PS is not requiring hydraulic assistance there is still power from the motor required to breach the 1200psi (ish) pressure release valve so the pump can keep pumping and circulating fluid.

Therefore in the case of setting up a twin stage pump, one for the PS the other for the winch, when not winching I don't want any pressure build up within the winch circuit constantly taking power from the motor. This should be easily achieved by by-passing the pressure release valve and allowing the fluid to flow back directly into the resivor with not pressure buildup. Then when I want to winch I close the open port to the resivor, 1200psi (ish) is created in the system and off I go winching.

I will try and get a diagram up in the next couple of days.

- David.

Dirty wrote:

me3@neuralfibre.com wrote:
Nup - my brain failed on that one.
Can you draw a diagram?

Paul

Within a hydraulic system there needs to be a pressure release valve which controls the maximum pressure created by the pump. In the case of the power steering when not moving the wheel, there is no need for any fluid supply to the steering box, so all fluid is exhausted though the pressure release back into the resivor. As without the pressure release valve fluid pressure would keep climbing until either the pump stalled or a pipe/seal burst. So even when the PS is not requiring hydraulic assistance there is still power from the motor required to breach the 1200psi (ish) pressure release valve so the pump can keep pumping and circulating fluid.

Therefore in the case of setting up a twin stage pump, one for the PS the other for the winch, when not winching I don't want any pressure build up within the winch circuit constantly taking power from the motor. This should be easily achieved by by-passing the pressure release valve and allowing the fluid to flow back directly into the resivor with not pressure buildup. Then when I want to winch I close the open port to the resivor, 1200psi (ish) is created in the system and off I go winching.

I will try and get a diagram up in the next couple of days.

- David.

all easy to acheive and with the one power steering pump!!!!! (a few mods to do though)

and you will require a seperate releif to dissapate excess oil flow.

just gotta ask the right people

1MadEngineer wrote:
all easy to acheive and with the one power steering pump!!!!! (a few mods to do though)

and you will require a seperate releif to dissapate excess oil flow.

just gotta ask the right people

1MadEngineer,

So where do I go from here.

Do I use the standard GU power steering pump or it there a better option?

What mods do I need?

- David.

Dirty wrote:

1MadEngineer wrote:
all easy to acheive and with the one power steering pump!!!!! (a few mods to do though)

and you will require a seperate releif to dissapate excess oil flow.

just gotta ask the right people

1MadEngineer,

So where do I go from here.

Do I use the standard GU power steering pump or it there a better option?

What mods do I need?

- David.

do some searching for hydro steering

those guys beef up thier flow rates etc when they do it, i think they were using ford pumps.

Shadow wrote: do some searching for hydro steering

those guys beef up thier flow rates etc when they do it, i think they were using ford pumps.

Good idea, didn't think of searching on that, just been trying hydraulic winches.

I will give that a go and see what I come up with.

- David.

1MadEngineer wrote:

Dirty wrote:

me3@neuralfibre.com wrote:
Nup - my brain failed on that one.
Can you draw a diagram?

Paul

Within a hydraulic system there needs to be a pressure release valve which controls the maximum pressure created by the pump. In the case of the power steering when not moving the wheel, there is no need for any fluid supply to the steering box, so all fluid is exhausted though the pressure release back into the resivor. As without the pressure release valve fluid pressure would keep climbing until either the pump stalled or a pipe/seal burst. So even when the PS is not requiring hydraulic assistance there is still power from the motor required to breach the 1200psi (ish) pressure release valve so the pump can keep pumping and circulating fluid.

Therefore in the case of setting up a twin stage pump, one for the PS the other for the winch, when not winching I don't want any pressure build up within the winch circuit constantly taking power from the motor. This should be easily achieved by by-passing the pressure release valve and allowing the fluid to flow back directly into the resivor with not pressure buildup. Then when I want to winch I close the open port to the resivor, 1200psi (ish) is created in the system and off I go winching.

I will try and get a diagram up in the next couple of days.

- David.

all easy to acheive and with the one power steering pump!!!!! (a few mods to do though)

and you will require a seperate releif to dissapate excess oil flow.

just gotta ask the right people ;)

Does that mean it'll be releving at high RPM all the time?

Paul

Most likely.

I am assuming that there is a flow control within the PS box, that way there is no noticeable change in steering characteristics no matter what rpm you are at. You can assume that there is enough oil flow at 1000rpm and spinning it any fast just blows more through the releif valve.

- David.

Flow control is uaually in the pump itself. Spinning the pump faster will therefore make no differance to output flow. Modify the flow control (usually orifice and relief) and you can get a higher flow rate from the pump.

You can get seperate piority type flow control valves, to fit inline. Modify or change pump to give you your 30-50l/min for winching circuit and controlled to 8-10l/min for steering.

Could change your pump to a Vickers vane pump (some were fitted to Mack and KW trucks for PS) and you can have the option straight outlet (no flow control, no relief), controled output flow with relief (PS pump) or piroity output flow (1 x controlled flow with relief for PS, and 1 x seperate non controlled flow output for aux circuit)

If you go more flow and pressure you increase required (pump) input HP, this may test belt drives a bit. General rule of thumb, for every 1gpm (3.785l/min) at 1500psi needs 1hp to drive the pump

Old Ford power steer pumps (XY,XA,XB) were scary at high speed.
At carpark speeds with the engine just over idle you can easily steer with one finger but on the highway at 120km/h+ with a short diff ratio (3200-3500rpm) steering is VERY light and VERY fast with next to NO road feel.

I think this is why these pumps are good for hydro steer setups, they are a bit primitive in their design but virtually bulletproof.
Flow must increase considerably with revs...?

I have a few of these in the shed... PM me if interested.
All in better condition than the one in the pic above. I ripped that pic off Ebay.
Jas.

ricky1970 wrote: Could change your pump to a Vickers vane pump (some were fitted to Mack and KW trucks for PS) and you can have the option straight outlet (no flow control, no relief), controled output flow with relief (PS pump) or piroity output flow (1 x controlled flow with relief for PS, and 1 x seperate non controlled flow output for aux circuit)

If you go more flow and pressure you increase required (pump) input HP, this may test belt drives a bit. General rule of thumb, for every 1gpm (3.785l/min) at 1500psi needs 1hp to drive the pump

Ricky,

Was looking at something like a Vickers, but with needing pulley blocks to convert them to belt driven and other stuffing around I was going to start with a PS unit and modify it as a much cheaper option as I really need minimal flow when you get into these sort of solutions.

As for getting the power to it, when I have settled on the pump I will look at that. Maybe as easy as getting the serpentine setup from a TB onto the TD.

want33s wrote:Old Ford power steer pumps (XY,XA,XB) were scary at high speed.
At carpark speeds with the engine just over idle you can easily steer with one finger but on the highway at 120km/h+ with a short diff ratio (3200-3500rpm) steering is VERY light and VERY fast with next to NO road feel.

Jas,

Looks like a good option. Let me do a little more research and I will get back to you on one of those pumps gathering dust.

David.