F1 Timing Gear Damper, a closer look

[Brian.G]

Amazing, did you manage to get a complete unit ?

Its 98% Complete yes.....and what a journey it was finding one! A childhood dream come true at last.

Have remainder parts being sourced at the moment from the guys at Modatek.

Brian,

[riff_raff]

I understand that the cam lobe profiles on F1 engines were ground with some compensation for torsional deflection along the shaft length.

[hardingfv32]

What is the design of a 'cam roller damper' look like?

Brian

[63l8qrrfy6]

What is the design of a 'cam roller damper' look like?

Brian

Hi Brian,

'Roller damper' is the colloquial name for a Salomon type centrifugal pendulum absorber.
It consists of a flange with equi spaced holes about the CL of the shaft in which the rollers (similar to a roller bearing element, but usually made of a high density metals such as tungsten) lie. Their axes are parallel to the shaft axis and they are free to orbit within their bores once the centrifugal force overcomes gravity. The axial motion is constrained.

[Brian.G]

What is the design of a 'cam roller damper' look like?

Brian

Hi Brian,

'Roller damper' is the colloquial name for a Salomon type centrifugal pendulum absorber.
It consists of a flange with equi spaced holes about the CL of the shaft in which the rollers (similar to a roller bearing element, but usually made of a high density metals such as tungsten) lie. Their axes are parallel to the shaft axis and they are free to orbit within their bores once the centrifugal force overcomes gravity. The axial motion is constrained.

The Patent and drawings for said damper,

https://www.google.com/patents/US5295411

Brian,

[63l8qrrfy6]

I think the original patent was the one submitted by Salomon half a century before (see citations) hence the name of the device.

[riff_raff]

I believe they are also called bifilar pendulum torsional absorbers.

https://www.researchgate.net/publicatio ... ng_engines

[63l8qrrfy6]

Bifilar means that they are suspended at 2 points - to my knowledge these have not been used in F1 and I think the reason is that they tend to have higher inertia. They have been used in automotive cranks and are commonplace in helicopter rotors though.

But they too are a type of centrifugal pendulum absorbers as you have stated, just not the same as Salomon/roll form type.

[Smokes]

Just Curious I wondering if these type of dampers are used on traverse drive mechanisms where servo motor drives something backwards and forwards.

[Brian.G]

Just Curious I wondering if these type of dampers are used on traverse drive mechanisms where servo motor drives something backwards and forwards.

They are sometimes used between ball screw and motor in the form of an elastomer coupling. I would think the torsional vibration would be greater however with a stepper as opposed to a servo due to how a stepper works and its positioning via step pulse, or micro steps. This vibration can sometimes show itself with rack and pinion stepper drives too, but in a lot of cases with racks and indeed ballscrews a toothed belt drive is an easy dampening option - it can also help too with packaging length.

Brian,

[jtveg]

Thanks for a very interesting, insightful and technical article. I very much appreciated the many detail photos.

I look forward to many more such articles on the inner workings of F1 engines.

[Brian.G]

Thanks for a very interesting, insightful and technical article. I very much appreciated the many detail photos.

I look forward to many more such articles on the inner workings of F1 engines.

Thanks - and welcome to F1 Technical!

Brian,

[Brian.G]

A video on the timing Gear Damper discussed in this thread,



Brian,

[gruntguru]

Back on the issue of damping and friction.
There are a lot of hydrodynamic bearing surfaces in that assembly contributing a significant amount of viscous friction. No question it is a damper. If an undamped spring was sufficient, a single quill shaft at some point along the timing drive (eg the quill shaft in the cam) would suffice.

Which reminds me of another observation. The quill shaft inside the camshaft has another benefit - it drives the cam at a location some distance from the end of the cam. The natural frquency of the cam under excitation at that point will be significantly higher. Furthermore, cylinder to cylinder timing variation will be reduced - the long cam becomes two shorter cams.

[Brian.G]

Which reminds me of another observation. The quill shaft inside the camshaft has another benefit - it drives the cam at a location some distance from the end of the cam. The natural frquency of the cam under excitation at that point will be significantly higher. Furthermore, cylinder to cylinder timing variation will be reduced - the long cam becomes two shorter cams.

Yes, discussed in video above approx 33min in.

Brian,