SO... A 4-link with no ability for one of the links to shrink and grow will break mounts or welds??? THat's interesting. WHat would happen if you made REAL beefy mounts etc. is it just a matter of time before SOMETHING folded and gave way like a link or that housing???
If you built it super beefy, then you would just limit articulation.
The stuffed side rolls back, and the droop side wants to roll forward, so if the links don't allow the housing to roll forward, the wheel doesn't droop, and goes airborne. it will probably be a little springy, as steel has some give. You'll be stressing all the components of the suspension.
I like the idea of a splined "slip yoke" style link to cure this. Better anyway then a ruber deal that'll wear out and be of concern (or maybe I'm wrong on this and it's no concern at all???)
In my experience (and maybe salt/grime laden climate?) a rubber bushing will outlast pretty much any sort of spherical bearing end.
It does allow some "give" which many folks don't like in a linked suspension. Too soft bushings, especially on all link attachment points can cause something similar to axle wrap under high power.
I'd imagine a 4-link would be just the same though eh, the individual links have in different path and diferent centre-points that the "Arc" of the arm is based off eh.
a true 4 link (4 attachment points at the axle and 4 attachment points at the frame) can be engineered (control arms lengths and angles wrt each other) such that there can be nearly no rotation of the axle through it's travel.
In the extreme case, you could design a 4 link such that the axle rolls in the same direction upon compression and extension of the suspension (geez...that sounds like a bit from Schoolhouse Rock).
It's definately a more complicated design since you have a lot more factors to consider, like how it affects castor, as well as roll center and dive/squat behavior.
You could benefit from this in that stuffing one side would actually force the other side to extend, but in practical terms, to do that, you may not have room for a driveshaft, or you may have to put link ends in the driver's crotch or something, so it's a difficult problem.
There's no free lunch.
SO is this like a "Radius arm" set-up??? How does the 80-series combat this??? AND, how does the Panhard bar counteract this, does the "johnny joint" have enough rotatrional allowence to not bind up???
This is Exactly a radius arm design, same as an LC80, however, with the axle end link points behind rather than below the axle.
The 80 series uses rubber bushings to locate the axle, so there's enough "give" in the bushings to allow the axle to articulate within the use case Toyota expects for an unmodified vehicle.
The Panhard bar doesn't counteract the binding. In many cases a panhard just acts as another link with more restriction, however, it's is VERY necessary in a radius arm, non-triangulated 3 link, or 4 link to locate the axle under the vehicle. In the worst link designs, the axle is forced left/right so much under articulation that the panhard bar will also prevent articulation.
Sounds like IPOR definately has this one under control :victory:
I sure haven't found anything...)
