riff_raff wrote:There was some justification at one time for gearbox mounted clutches, since a clutch failure would not necessitate an engine change. Don't know if this is still true though.
autogyro wrote:Who needs a clutch?
DaveKillens wrote:One important consideration is to pass as little torque as possible through the clutch. The more torque you have to deal with, the larger and beefier the clutch has to be.
And the torque is at it's lowest value coming off the crankshaft, before it goes through gearing that multiplies torque.
autogyro wrote:Eh what is this 'electric transmission' you mention Edis?
What has this got to do with the need for a clutch in F1?
Dry plate clutching an ic engine to a gearbox input shaft is very very crude.
Often the wheels spin up uncontrolably or the engine stalls.
Hardly modern efficiency is it.
The cone clutch on the 1908 Panhard et Levasser I am helping to rebuild is more efficient for the purpose. Very little slip or chances of engine stall amd over 100 years old. Twin cam engine as well.
riff_raff wrote:Dave Killens,
F1 friction clutches are basically shaft speed synchronization devices. This means that their function is to transmit power between two shafts (the crank and trans input) turning at different speeds by slipping, until the two shaft speeds are equalized. At that point it simply becomes a fixed coupling.
The excess power produced during the slippage is rejected as heat. This power term is simply the transmitted torque times the relative speed difference divided by a power constant. Friction clutches are designed by thermal capacity, and not so much by an ability to transmit torque. If torque transmission was the only concern, then a single clutch plate could be made to work by increasing the clamping force. The reason multiple plates are used is to provide enough thermal mass to prevent the temperature rise in the plates during slippage from exceeding safe levels for the CRC plate materials. The reason small diameter plates are used is to minimize the polar inertia of the clutch pack and to keep the engine CL as low as rules permit.
The AP drawing I linked is for a 115mm (4.5 inch) dia clutch, which is quite small. I believe current rules require an engine crank CL at least 58mm above the reference plane (ie. the underwing OML). So a 115mm dia (57.5mm radius) clutch pack would seem appropriate.
Also, the current rules allow a clutch change regardless of whether it's engine or crank mounted. As long as the shaft it's mounted on is turning at crank speeds.
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