Reinvented axle???

[Cheetah 210es]

Re: Reinvented axle???

Most trucks with lift axles are fitted with a system that only allows it to be lifted temporarily either by time or speed, typically 90 seconds or speeds below 15mph

 

[86 century]

Re: Reinvented axle???

My wifes uncle has a highend rv with a tag axle that lifts if the steering is turned past a certain point at low speeds.
Its all fully automatic so no forgeting to put it back down.
For the cost of puting a system like this on a trailer you could buy a liftime supply of tires.
Good luck

 

[Cheetah 210es]

Re: Reinvented axle???

Proper trailer tyres and and making as wider turn as possible and you dont need lift/steer axles

 

[smokeonthewater]

Re: Reinvented axle???

Most trucks with lift axles are fitted with a system that only allows it to be lifted temporarily either by time or speed, typically 90 seconds or speeds below 15mph

none that I've ever seen or operated.... Pulled a lot of spreads where you had to walk back and flip a valve on the trailer... Pulled many detachable and folding neck lowboys that were the same way.... driven several 4 axle tractors with a valve and pressure gauge usually on the floor between the seats.... all manual and no time limits.... better remember to put that 4th axle down before rolling across the scale or get the wallet out.
I'm not saying that there aren't automated systems on trucks but definitely not on "most"

 

[Cheetah 210es]

Re: Reinvented axle???

none that I've ever seen or operated.... Pulled a lot of spreads where you had to walk back and flip a valve on the trailer... Pulled many detachable and folding neck lowboys that were the same way.... driven several 4 axle tractors with a valve and pressure gauge usually on the floor between the seats.... all manual and no time limits.... better remember to put that 4th axle down before rolling across the scale or get the wallet out.
I'm not saying that there aren't automated systems on trucks but definitely not on "most"

Sorry, should have pointed out I'm originally from England where a 6 axle truck runs upto 97000lb and we typically have a lift on tractor and at least 1 lift on trailer. The truck I last drove there had a lift/steer axle on tractor that automatically came down when load on drive axle exceeded 17500lb and front axle on trailer dropped down when weight on rear bogie exceeded about 16000lb. When empty the trailer axle lifted itself at speeds above 20mph. To help with traction (most tractors are 6x2) you pressed a button in cab that temporarily dumped air pressure from lift axle transfering its weight to drive axle. With electronic controls for air suspension and abs/ebs its a pretty standard setup found on most rigs. I should remember where I am :facepalm:
http://www.hendrickson-intl.com/pdfs/Auxiliary_PDFs/H633.pdf
http://www.wabco-auto.com/products_wabco/suspension-control/lift-axle-control-valve

 

[smokeonthewater]

Re: Reinvented axle???

ooooooh fancy shmancy..... makes a bit more sense with geography thrown in

 

[ajgraz]

Re: Reinvented axle???

To the OP:

Whatever you come up with, if you describe it on a public forum first you won't be able to patent it.

 

[Cheetah 210es]

Re: Reinvented axle???

K. Been thinking about this some. Air suspension on small trailers is already available, http://www.ridetheair.com/images/LBS-5.jpg
Some SUV's have air on the rear and I've seen kits to fit airbags to trucks (both full air and air helpers that bolt on top of leafsprings or sit inside coils) My thought was a pair of helpers on rear springs of trailer that you inflate when needed (how many peeps would bother to get out to do this is a seperate question) this would push rear axle down and through the balance beam lift the front axle.
I think ill just not screw my trailer round on itself unless I absolutely have to.
I know this wont work on torsion axles

 

[Silvertip]

Re: Reinvented axle???

"this would push rear axle down and through the balance beam lift the front axle." If the trailer were heavily loaded you would likely blow out both rear tires because you just doubled the load on them. Lifting axles on trucks is not a concern in that regard. It is all about axle weight. The tires on those vehicles are perfectly capable of supporting the weight. Most states have very strict load limits which is a combination of maximum weight the state allows and the maximum weight any single axle can have. The solution to lower axle weight is to add more of them.

 

[JDA1975]

Re: Reinvented axle???

"this would push rear axle down and through the balance beam lift the front axle." If the trailer were heavily loaded you would likely blow out both rear tires because you just doubled the load on them. Lifting axles on trucks is not a concern in that regard. It is all about axle weight. The tires on those vehicles are perfectly capable of supporting the weight. Most states have very strict load limits which is a combination of maximum weight the state allows and the maximum weight any single axle can have. The solution to lower axle weight is to add more of them.

The problem he seeks to rectify is dragging a tire while turning tightly, if your turning tight enough to drag a tire, you will be going slow...the rated tire weight is based on cruising speed, so for the short time it takes to make a turn raising one axle should be ok. If his trailer is so heavily loaded that raising 1 during a slow turn causes problems, he should have higher rated axles and wheels anyways! I have raised axles on a split tandem trailer carrying 40k lb loads on the rear 2 axles (20k each) in order to back up/turn...try doing it without raising one, and even though the axle is rated for 20k I have never cracked/bent an axle raising one and putting 40k lbs on a single axle

 

[Cheetah 210es]

Re: Reinvented axle???

"this would push rear axle down and through the balance beam lift the front axle." If the trailer were heavily loaded you would likely blow out both rear tires because you just doubled the load on them. Lifting axles on trucks is not a concern in that regard. It is all about axle weight. The tires on those vehicles are perfectly capable of supporting the weight. Most states have very strict load limits which is a combination of maximum weight the state allows and the maximum weight any single axle can have. The solution to lower axle weight is to add more of them.

No it wouldn't. Apart from speeds involved they do the same tests to get load rating. P LT and ST tires are tested at i think 70mph +/-
Truck tires are tested at slightly lower speeds.

 

[Cheetah 210es]

Re: Reinvented axle???

• Tire Load in Kilograms +0 to –18 kg (lbs +0 to –40 lbs)*
The tire shall be run without interruptions at these intervals:
4-hour test: 85% as a percentage of tire maximum load rating
6-hour test: 90% as a percentage of tire maximum load rating
24-hour test: 100% as a percentage of tire maximum load rating
speed in kilometers per hour: 120 kph+0 to –3.2 kph (75 miles/hour +0 to –
2 mph)
24 Hours at 100% load at 75mph - doubt a few minutes at 10mph will hurt.
Adding axles increases the problem this thread was trying to fix.

 

[maproy99]

Re: Reinvented axle???

To address some comments, I'm not going to patent this, this was just an idea I came up with thinking about the problem for about a whole of 10 minutes while going to bed one night. I knew it may not turn out to be a solution or a good solution, just wanted to put my thinking out there to see what comments came off it. I don't plan to go cutting any axles on my trailer (why make a problem), but if someone wants to go try this then go ahead. However I do like the airbag suspension idea that came out of it, thanks to whoever suggested that. And I never though this would hit 2 pages long.

 

[Silvertip]

Re: Reinvented axle???

No it wouldn't. Apart from speeds involved they do the same tests to get load rating. P LT and ST tires are tested at i think 70mph +/-
Truck tires are tested at slightly lower speeds.

Yes you would double the load on the rear tires. We are talking about a tandem boat trailer. Lifting the front axle transfers that load to the tires that are on the ground. A tandem boat trailer typically has a pair of 3500# axles with tires to match that rating. That makes for a 7000 GVWR. Put 7000# on a single 3500# axle whether you are turning, stopped or going 10 MPH and there will be damage. Boat trailers also tend to be loaded very close to their GVWR and in may cases are already overloaded.

 

[Silvertip]

Re: Reinvented axle???

To address some comments, I'm not going to patent this, this was just an idea I came up with thinking about the problem for about a whole of 10 minutes while going to bed one night. I knew it may not turn out to be a solution or a good solution, just wanted to put my thinking out there to see what comments came off it. I don't plan to go cutting any axles on my trailer (why make a problem), but if someone wants to go try this then go ahead. However I do like the airbag suspension idea that came out of it, thanks to whoever suggested that. And I never though this would hit 2 pages long.

No problem. You just experienced what happens when someone thows something onto a forum. You get some initial responses but then all at once the discussion takes a hard turn and the train runs off the rails. If we didn't think, we would still be pounding wet clothes on a rock in a stream. While this idea was not out of the relm of possibility, there are existing ways to implement your idea. The problem is that is simply not practical in this instance.

 

[maproy99]

Re: Reinvented axle???

No problem. You just experienced what happens when someone thows something onto a forum. You get some initial responses but then all at once the discussion takes a hard turn and the train runs off the rails. If we didn't think, we would still be pounding wet clothes on a rock in a stream. While this idea was not out of the relm of possibility, there are existing ways to implement your idea. The problem is that is simply not practical in this instance.

And it isn't like I am trying to fix it in the first place, just trying to come up with a way to fix it for the heck of it.

 

[Fleetwin]

Re: Reinvented axle???

Seams like everyone that is suggesting lifting an axle, or doing anything that removes the tire from the road for making turning easier, is forgetting one very important issue. Weight and load rating. A rig has all it's tires and wheels on the road to carry the load. You take one of them away or change the geometry of contact with the road (which happens oftentimes when making turns anyway) the weight rating of each tire and wheel become null. This presents an unsafe condition and increases the risk of tire failure.

Picture the folks that move houses. You won't see a tire leave the surface it's in contact with. They move in unison. If one leaves the surface several will blow.

The weight rating, of each axle, was not forgotten. Once off highway, you can do whatever you want. Granted, the wheels, tires, axle, etc. would have to be able to handle a good percentage of the load. Not all of it. Not uncommon with heavy trucks. GVW ratings are based on "on road" ratings. Bridge laws, etc. There is some wiggle room when you get off road. In most cases (wheel ends), the axles, wheels, tires can handle it.

As an example; A typical six axle concrete mixer has six axles down, "on road". Off road, they lift three (two pushers and one tag) to aid in manuevering. Works fine off road. The 46K# rear axles can handle the weight.

The real issue is developing a workable lift axle for a boat trailer. Without air brakes, suspension, etc., it gets complicated-fast.

 

[Silvertip]

Re: Reinvented axle???

Forget the truck stuff -- we understand the loading and axle weight maximums. Get back to the boat trailer, fully loaded, maxed out tire ratings, maxed out axle ratings -- all very real world. You lift one axle and you have an instant overload on both axle, tires, and springs. Something WILL break.

 

[maproy99]

Re: Reinvented axle???

The only solution to this problem seams to be make a full time axle with a part time helper axle. If anyone can come up with a better solution then that please post it.

 

[smokeonthewater]

Re: Reinvented axle???

um, there is no problem


also double the rated load on a tire, any tire, in good shape will not automatically cause damage at low speed. Even at high speed, the damage would generally not occur until the tire began to overheat. Hitting a pothole or rough section of road at 60 mph could exert many times more force on the tire than double capacity and that often does no damage.

I hauled 4-5 tons of stone in the bed of a 1/2 ton chevy with 235/75r15 lt's on the back at under 10 mph for a distance of 3-4 miles about a dozen times when I was in high school working on my parents driveway. Those tires were on the truck another 5 years or so with no problems. The rear springs on the other hand were trashed and I swapped em out the next week.