Belts/Accessories on F1 engines?

[SBarretta]

I was just thinking, and road engines obviously have AC pumps, water pumps, fans, alternators, timing belts, etc... but I've never noticed these external things on F1 engines. What accessories or attachments do F1 engines have, and how are they driven? There's got to be something driving the camshafts, something to circulate cooling/lubricating fluid, and something to generate electricity, but in modern F1, where are these things located, and how do they work?

[Tim.Wright]

They use thin, lightweight gears under the front face of the engine to drive everything

[SBarretta]

Look at that, thanks a lot. I was figuring that belts wouldn't be able to cope with the extreme speed and force put out by an F1 engine.

[spacer]

I wouldn't overestimate the force needed for a belt to drive the camchain of such an engine. With all the lightweight engineering in the entire valvetrain, there are numerous timing-belt operated engines outside of F1 that probably need a lot more power to drive the camshafts and valvetrain.

How those belts hold under high engine speeds I don't know (but then again, there are belt-driven inlet disks on two-strokes that rev up to similar rpm's). I'd suspect it has more to do with timing accuracy and reliability under high acceleration figures.
But I'd be happily be proven wrong though.

[marcush.]

the question was related to accesories: pumps and alternator .

and as i understand you have the option of chain and direct drive of components as well... through a drive coupling

but is everything geardriven todays? I´m not sure.

[SBarretta]

I was curious about camshafts as well, along with everything else that is conventionally belt driven (so obviously water pump, alternator, etc...)

I was more concerned about the speed with which f1 engines gain and drop revs. I think a belt or chain might flex and become lose or possibly slip after being 'kicked' so hard. But if belts are used on similarly jumpy two stroke engines, then maybe belts would work, but gears work better?

[riff_raff]

Timing belts are actually quite an attractive option in some respects for driving cams and engine accessories. The belt system is lightweight and provides some vibration dampening. The drawback with belts is that the installation tends to be bulkier, less reliable, and somewhat less accurate than gear drives.

Over the years, F1 engines have used gears, chains, belts, and various combinations of the three for cam and accessory drives. For example, the Cosworth DFX used gears for the cams and a timing belt for the pumps, the Cosworth GBA used chains for the cams and belts for the accessories, while the Cosworth CA2011 uses gears for both drives.

Of course, now that F1 cars have an abundance of recovered energy I'd like to see the use of electrically driven pumps. This would allow the pumps to be run at variable speed/flow giving much better efficiency, and the pumps could be remotely located from the engine giving more packaging flexibility. Production cars are already heading in this direction. F1 should do likewise.

riff_raff

[Tommy Cookers]

Good point, well made !

Power steering pumps in road cars or F1, electric ?

[riff_raff]

Good point, well made !

Power steering pumps in road cars or F1, electric ?

Tommy Cookers,

There are already many examples of electric motor driven accessories on production cars. Electric power steering systems and electric A/C compressors are used on most hybrid cars, since the IC engine does not operate under some conditions. There are a few models that also use electric coolant pumps, and electric fuel pumps are now universal. Soon we will even see electric brake calipers on production cars.



riff_raff

[tok-tokkie]

How small & light are the electric motors for the pumps etc? Is there a weight penalty when compared to a belt drive? What sort of motors are they? (I was very surprised by the electrically operated brake drawing.)

[marcush.]

well it depends on the power needed ...but there are big moves in the automotive industry to electrify all ancilliaries it´s sort of a buzzword.
You are looking for brushless ec drives there .
The latest direction is to go for HV components...as for example a fan drive for a 12V system and 1000W (which is actually reality in some cars of the Volkswagen range!) will draw insame amps when used under full power(14Vx1000W=71Amps....)

so when looking at things like steerring pumps ,hvac compressors ,water pump drives you quickly run into serious issues with a 12 Volt system ..that was the reason for the the industry aiming for the halfway house of 48V systems that never made it into series production and now with Hybridisation the draw will most likely go for using the already available HV supply.
But for compactness of drives that impose new challenges as the HV will need bigger airgaps to avoid arcing ...

[marcush.]

btw -the brake system above is siemens EWB stemmming from the old days of coaches....

Electronic Wedge Brake -the force is build not by the electric motor but by wedging behind the brakepad .The real test of it is the failsafe control of the wedge actuation to be able to control the brake force...
early tests in 2006 gave ridiculously short stopping distances ,halving them effectively...when siemens and conti merged the system somehow got lost in this as I understand.

[Tommy Cookers]

I know what is meant about current consumption and engines not operating !

A little-used (Peugeot) car of mine showed this difficulty. It had an electric power steering pump, and after restarting could lose its power steering interrmittently, eg when driving. The pump needed 22A to start and 14A continuously, but the supply was controlled by a relay giving priority in line voltage to the engine so able to kill the steering without warning when driving ! A new battery and 700W ? alternator cured the problem.

Now I have a car with Aircon, so a belt-driven pump, that turns continuously as the engine does. Wasteful ?
I'm scared to think about the power steering.


The electric brake looks like the Honda motorcycle (cable-operated) disc brake of about 40 years ago, lacking in feel and demanding maintenance ?
Don't Siemens make lots of the things that we apparently need in this 21st century !

[marcush.]

Sometimes one has to scratch his head about advances in automotive ....the industry still does not realise nobody would have ever asked for airbags and other stuff if them OEMs had not pushed forward with it ....now we are into electrification everything .A bit much to ask when you have already decided to rely on Battery storage of your energy...

[riff_raff]

Sometimes one has to scratch his head about advances in automotive ....the industry still does not realise nobody would have ever asked for airbags and other stuff if them OEMs had not pushed forward with it ....now we are into electrification everything .A bit much to ask when you have already decided to rely on Battery storage of your energy...

marcush,

While both F1 accessories and production automotive accessories would benefit from electric drive, the two types of engines are operated differently and thus would not benefit in the same way.

F1 race engines run mostly at WOT conditions and maximum BHP output is paramount. Driving the accessories electrically would free up a significant additional amount of useable HP (maybe 20 to 40 HP?) at the flywheel that would normally be lost to driving the accessories. The electric motor systems would add some weight, but since most F1 cars carry ballast, the motor system weight would just displace ballast rather than increasing total weight.

On the other hand, production cars run mostly at part throttle, light load, low rpm conditions. But most of the engine driven accessories are sized for worst case high load, high rpm operation, which means they're way oversized for most of the engine's operation. Driving these accessories electrically and independent of engine speed gives much better fuel economy. Maximum HP is not so much of a concern however. There would be more electrification of auto accessory drives were it not so costly.

Regards,
riff_raff