Power Steering Possibility?

[wheelspinner]

so you are talking about a system with a ram on the drag link or tie rod?

No just the torque generator.

Re read the thread to get my thoughts back on track.

 

[m16ty]

The way the torque generator works is it uses hyd pressure to assist on the output, it's all self contained (no cylinder the drag link or tie rod).

During normal driving, it's unlikely that the torque generator would put any more stress on the stock steering gear (it takes "X" amount of torque to steer the tires and even though the driver has it easier, it's still no more stress on the steering box). Now if it takes more torque than normal to steer the tires ( tire in rut, steering hard and fast in a emergency situation) you could overload the stock box. Say the torque generator cuts the steering effort by half, that means your measly arms are capable of putting twice the torque on the steering box than you normally could.

It could also be argued that if you encounter stresses in the steering system enough to destroy the steering box with a torque generator, you would loose control of the vehicle anyway with stock steering because you couldn't hold the wheel.

Just remember that modifying any steering system is serious business and people can die if done wrong.

 

[rustystud]

The way the torque generator works is it uses hyd pressure to assist on the output, it's all self contained (no cylinder the drag link or tie rod).

During normal driving, it's unlikely that the torque generator would put any more stress on the stock steering gear (it takes "X" amount of torque to steer the tires and even though the driver has it easier, it's still no more stress on the steering box). Now if it takes more torque than normal to steer the tires ( tire in rut, steering hard and fast in a emergency situation) you could overload the stock box. Say the torque generator cuts the steering effort by half, that means your measly arms are capable of putting twice the torque on the steering box than you normally could.

It could also be argued that if you encounter stresses in the steering system enough to destroy the steering box with a torque generator, you would loose control of the vehicle anyway with stock steering because you couldn't hold the wheel.

Just remember that modifying any steering system is serious business and people can die if done wrong.

I agree that it would be hard to overstress the steering box with a torque generator. The military designed it to be able to go through extremely difficult terrain, that includes ruts. Someone might say that the human is the fuse in the circuit, but consider this. When I was in the Corps we had some guys that I was sure had gorilla DNA in them ! They had arms that would make Arnold say "I won't be back ! " . They
could hold that wheel and make that truck go through anything ! I'm sure the military thought of that too, and included that in there specs for the amount of torque that gear would have to endure. All the torque generator does is give us normal mortals the same advantage as the "Arnolds" have. But if that is not true I have 3 spare gear boxes .

 

[mudguppy]

Since I made my post in this thread yesterday and read the comments, I'm going to hold off on the torque generator and explore using a orbital valve from a hydrostatic unit. I've got several hydrostatic units in my stash of parts that came off various scrap equipment so it won't cost me anything to play with it.

I'm thinking the biggest challenge with using a chain drive orbital valve is figuring out how to "time" it with the stock system. Looks like it's going to take some trial and error and a lot of figuring of sprocket sizes and slave cylinder sizes to balance the system.

An orbital valve displaces a fixed volume of fluid per rotation. The in-line column and drag link valves transfer rotational torque or axial force and apply hydraulic pressure to assist until this force is neutral - this is how the steering is assisted; hydraulic pressure is applied until 'zero force' is sensed on the input side. Chaining an orbital valve to the column and asking it to provide 'assist' will be impossible - the difference between input and output will always be lagging and the gap will never close. Actually you will likely find binding between the stock manual system and the separate hydraulic system.

Also, assuming you can perfectly match the column and valve ratios, that just means the two systems will move parallel with each other - not likely to provide any assist. Furthermore, you will need to use a double-ended ram in your hydraulic system - single ended rams have different volumes on each side and will result in different turn ratios with your steering valve, further complicating the coordination. Double-ended rams with tie-rods to each steering knuckle also result in different turning arcs between the two knuckles compared to the natural arcs created with a single tie rod - this creates binding.

I think you'll have trouble making a system like this successful because the intents are different - orbital is fixed input/output relationship, assist systems are always looking to balance the forces on the input.

 

[JasonS]

I just can't understand why folks want to cobble garbage together to save a couple hundred bucks.

If I were in a wreck, I feel confident that I can defend my choice of steering gear: it matches an OEM installation for a similarly sized vehicle using parts equal to or stronger than the original M35 truck.

For those who want to use torque generators, servos, misc garbage, etc. How would you argue that your system was properly designed or even reasonable? NO other on-road vehicle uses that kind of system? Think hard about why this might be.

 

[Lieutenant Dan]

Wrong sir, I can show you pictures of garbage trucks and jockey trucks that are road legal in pa and go through a semi annual inspection with full hydraulic systems. There is nothing wrong with a torque generator. I called and talked to eastern about this the other day, and they said they have sold hundreds of kits and have never had problems with them or failures of gear boxes. Could he be lying..... Sure..... But I'm assuming a big company like that wouldn't put out a bad product, one accident one lawsuit and they are out of business permanently

 

[Lieutenant Dan]

What's the difference, blow a brake line and some one is getting hurt or killed..... I see nothing wrong with a torque generator.

 

[JasonS]

Wrong sir, I can show you pictures of garbage trucks and jockey trucks that are road legal in pa and go through a semi annual inspection with full hydraulic systems. There is nothing wrong with a torque generator. I called and talked to eastern about this the other day, and they said they have sold hundreds of kits and have never had problems with them or failures of gear boxes. Could he be lying..... Sure..... But I'm assuming a big company like that wouldn't put out a bad product, one accident one lawsuit and they are out of business permanently

I'd love to see the pics.

 

[m-35tom]

I'd love to see the pics.

I also would like not only like to see pic, but know the full real story with the restrictions placed on the vehicle

 

[Lieutenant Dan]

I can get pictures of our jockey truck Monday, the garbage trucks I'll see if my buddy can get pictures, I know where I used to work, we had a customer berks products, search them on the internet..... Large concrete company that had probably close to 30 Osh Kosh cement trucks that had full hydraulic steering and they were street legal.

 

[JasonS]

Look, my point is that the Ross and Saginaw types of steering systems are ubiquitous on larger cars, pickups, light, medium, and heavy duty trucks, etc. Basically, everywhere you have a high speed over the road vehicle. Please make a technical argument why your system is better/ safer.

 

[m16ty]

An orbital valve displaces a fixed volume of fluid per rotation. The in-line column and drag link valves transfer rotational torque or axial force and apply hydraulic pressure to assist until this force is neutral - this is how the steering is assisted; hydraulic pressure is applied until 'zero force' is sensed on the input side. Chaining an orbital valve to the column and asking it to provide 'assist' will be impossible - the difference between input and output will always be lagging and the gap will never close. Actually you will likely find binding between the stock manual system and the separate hydraulic system.

Also, assuming you can perfectly match the column and valve ratios, that just means the two systems will move parallel with each other - not likely to provide any assist. Furthermore, you will need to use a double-ended ram in your hydraulic system - single ended rams have different volumes on each side and will result in different turn ratios with your steering valve, further complicating the coordination. Double-ended rams with tie-rods to each steering knuckle also result in different turning arcs between the two knuckles compared to the natural arcs created with a single tie rod - this creates binding.

I think you'll have trouble making a system like this successful because the intents are different - orbital is fixed input/output relationship, assist systems are always looking to balance the forces on the input.

That makes sense to me. I knew about some of the problems you mentioned (fixed displacement of orbital valves and difference in displacement on each side of cylinder) but haven't really thought it through. I was worried about this anyway and you confirm my suspicions.

 

[Lieutenant Dan]

I don't think anyone ever said it was better, and I'm not arguing with you. Ross boxes are still out there and from what information I have gathered all the rebuilders say that the ross box is far superior then the saginaw 710. I do believe I'm going to go with the ross box myself buy I'm not doing anything till I have all the funds. The ross box upgrade is gonna run around $1000 with a rebuilt box. The torque multiplier is gonna run probably around $800 so for the difference I think I'll go with the ross and add on the ram assist later.

 

[m16ty]

Here is a servo valve I came up with- http://woodwardsteering.com/images/power steering system components.pdf

Looks like this may be a good option. It's cheaper than the torque generators I've found and it will not put any more stress on the stock steering box (it will actually lessen the stress). You will have to add a cylinder to the cost and fab all that up.

 

[JasonS]

I don't think anyone ever said it was better, and I'm not arguing with you. Ross boxes are still out there and from what information I have gathered all the rebuilders say that the ross box is far superior then the saginaw 710. I do believe I'm going to go with the ross box myself buy I'm not doing anything till I have all the funds. The ross box upgrade is gonna run around $1000 with a rebuilt box. The torque multiplier is gonna run probably around $800 so for the difference I think I'll go with the ross and add on the ram assist later.

If there is any way I can help, let me know.

 

[rustystud]

Here is a servo valve I came up with- http://woodwardsteering.com/images/power steering system components.pdf

Looks like this may be a good option. It's cheaper than the torque generators I've found and it will not put any more stress on the stock steering box (it will actually lessen the stress). You will have to add a cylinder to the cost and fab all that up.

This system looks awesome ! I was going to use a ram assist even if I used the Ross or Saginaw gear, so no extra expense there, and being for race systems this valve will have better response then any normal steering gear ! Look at the replaceable spool valve for adjusting to your exact taste ! Thanks m16ty for sharing this info

 

[wheelspinner]

Look, my point is that the Ross and Saginaw types of steering systems are ubiquitous on larger cars, pickups, light, medium, and heavy duty trucks, etc. Basically, everywhere you have a high speed over the road vehicle. Please make a technical argument why your system is better/ safer.

I make my living selling parts to OEMs. Just because something is used by everybody doesn't mean its better. My equipment is top-end and must be specifically requested by the end user. Otherwise they get the standard (cheaper, more common) items. Not having an opinion here as I don't know hydraulics or steering theory all that well, just making a point that common items are not always the only correct choice.

 

[rustystud]

I make my living selling parts to OEMs. Just because something is used by everybody doesn't mean its better. My equipment is top-end and must be specifically requested by the end user. Otherwise they get the standard (cheaper, more common) items. Not having an opinion here as I don't know hydraulics or steering theory all that well, just making a point that common items are not always the only correct choice.

I agree with you wheelspinner. I have worked on hydraulic systems, built systems and the cheaper route is not always the best route. I was trained on hydraulic theory in the Marines and tech school. I have also worked on some serious off road equipment. The systems they use can vary wildly, it's just a matter of how the OEM wanted to get to point A to point B. I have seen the orbital valve used on a lot of big equipment, but that was the problem. They didn't have to go high speeds like on a hi-way. This system m16ty showed us is FOR high speeds, very high speeds !!! Maybe there is something there to pursue after all . Later this week I'm planning to give them a call and tell them what I'm wanting to use there system on. If they say NO WAY ! I'll know to stop this particular route an go a more conventional way.

 

[Lieutenant Dan]

But the time you buy that servo you might as well just buy a ross box, these guys are pretty much right.... You might save a bit at first but I think the steering box is the better route in the long run.....

i forgot to post my findings I'll do that this afternoon.

 

[m16ty]

But the time you buy that servo you might as well just buy a ross box, these guys are pretty much right.... You might save a bit at first but I think the steering box is the better route in the long run.....

i forgot to post my findings I'll do that this afternoon.

I'm not necessarily disagreeing with you but I am curious as to why you think the Ross box is a better route? I'm leaning toward the servo at the moment but I still could be persuaded otherwise.