TF106's suspension

[f1.redbaron]

I was reading an interview with Mike Gascoyne, and there was a part of it I didn't really understand (much to everybody's surprise ). Here it is:

"However, we've gone away from the rotary rear damper concept that we've had for the last couple of years to a linear rear damper. We've identified a damping problem with the car over the last couple of years, which we've now put right. "

Is this phrase "rotary rear damper", the English equvalent for spring or coil-type shock absorber, or is it something else? Also, is "linear rear damper" what they use on modern sports bikes?

What is the advantage of one over the other? Could it be that this is why Toyota's didn't like bumpy circuits like Interlagos and Shanghai?

Thanks.

http://www.f1technical.net/news/1579

[Guest]

this is really a rotary damper, made by Sachs, first for Ferrari with the F2003GA and the following year adopted by Sauber and Toyota. You could see Piola's drawings about it with a reaserch and I show you my own photo of the real thing :

[benjabulle]

sorry, didn't login, remi from gurneyflap.com

[f1.redbaron]

Thanks.

Yeah, I kind of figured I was way off.

[Lukin]

To put it another way; with a normal spring you get on most road cars, the more you compress it linearly (ie in a straight line) the more resistance there is. With the rotary spring, the more angular displacement you apply (through the bellcrank I assume?) the more resistance there is.

Same principal. Displacement proportional to resistance.

I wonder what sort of problem they had? I have to say I have trouble conceptualising how you it dampens. I assume the same principal of pushing oil through a cavity, but damn, it seems strange!

They are great for packaging, as that pic shows.

[dumrick]

This last post mixes up dampers and springs. You get rotary springs as easily as with a torsion bar. Angular dampers have the same working principle as linear ones. Historically, rotary dampers have been achieved also by energy dissipation through friction between two plates rotating against each other.

[Spencifer_Murphy]

I heard of the rotary damper from Sachs when it was first rumourd about it being used on the rear of the F2003-GA...but since then I havent heard much info about it. All i DO, know is that it is (or was) meant to be a revolutionary damper, which is different to normal linear dampers....but STILL a damper....NOT a spring (like torsion bars).

BTW...anyone know of any more detailed info on the rotary damper and how it works?

[scarbs]

Heres the info

http://www.s-r-e.de/owx_3_32257_2_0_0_0 ... 00000.html

Mike let the cat out of the bag on that one, I saw the dampers in testing and tackled him on them at the launch, but its clear he also spoke to everyone else about them.

The damper layout layout is new to F1, the torsion bars are vertical (like renaults) and the dampers sit in front of the torsion bars (and ahead of the axle) but the pushrod extends the dampers in bump (i.e. not compressing in bump) and the rockers extend forwards to a "T" bar which controls roll land connects the 3rd spring.
Notice he's moved to penske dampers and not remained with Sachs.

[RH1300S]

The rotary damper is not a new idea, Suzuki introduced one on their TL1000 way back around 1997 (us bikers always get there first ).

Instead of the piston moving in a linear fashion in a tube, the damping is achieved by parts rotating (think old fashioned friction damper ).

In the Suzuki, they had terrible stability problems - AFIK traced back to the damper not working well. My memory tells me that one problem with the damper was that it was highly sensitive to production tolerances due to the small amount of actual movement on the internals, so subtle damping was a hit and miss affair. I suppose even if precise tolerances are achievable for F1 teams, on any like for like comparison (same production tolerances) a linear damper will allow more subtle/responsive damping.

I am sure that I was read that because of the very small suspension movement at the wheel of an F1 car, some systems actually try an arrange the bell cranks to move the damper further for any unit of wheel travel (this gives a more subtle control).

[toyotaf1]

here are some pictures of the linear rear damper that toyota has just tested the jerez.

picture1

picture2

[scarbs]

I need to correct myself now seeing those pictures the dampers are operated in compression in bump and not Extension, it seems the bracket reaching arond the torsion bar\Rocker I mistook for the pushrod at the Jerez test last Dec.

[Guest]

In the Suzuki, they had terrible stability problems - AFIK traced back to the damper not working well. My memory tells me that one problem with the damper was that it was highly sensitive to production tolerances due to the small amount of actual movement on the internals, so subtle damping was a hit and miss affair. I suppose even if precise tolerances are achievable for F1 teams, on any like for like comparison (same production tolerances) a linear damper will allow more subtle/responsive damping.

I am sure that I was read that because of the very small suspension movement at the wheel of an F1 car, some systems actually try an arrange the bell cranks to move the damper further for any unit of wheel travel (this gives a more subtle control).

Why can't you do this with gear reduction with the rotary damper? I don't see why these problems can't be solved. There's no reason to convert the linear motion of the pushrod to a rotary motion (bell crank) back to linear (linear damper). I love the idea of having the bell crank be a damper. This problem can be solved, I wonder why Gascoyne gave up. I'm sure I don't have the whole picture.

[Spencifer_Murphy]

Thanx 4 the info on the rotary damper guys!

[DaveKillens]

Rotary dampers have been around for a very long time, I'm sure they were around before telescopic dampers. But telescopic dampers have been in vogue for quite a few decades now, and have been refined and work very well. To build a rotary damper that matches a linear damper would require high precision and a lot of testing. Who knows, maybe they build three dozen and only one or two pass the testing.
But with such a compact design, heat has to be an issue. I would believe that building a rotary damper that maintains correct tolerances and performance under heat cycles is a major undertaking.

[Guest]

Yes, it must be difficult, especially at 160bar (2320psi). I can't imagine
what kind of seals you need to take that kind of pressure.

Gascoyne has no excuse though, Ferrari has been running those since the launch of the F2003-GA.