Woodcutter wrote:Remundo wrote:[...] Each time you pass a sprocket to another, you lose a minimum of 5% power. So it's a bad point for the TAG that turns intrinsically too fast. [...]
Uh ...
Are you sure of yourself on this one then?
It seemed to me that rather around 0.98-0.99 the performance of a transmission between two gears damn good?
If your 5% is correct, it would mean that in a gearbox, we already lost around 20% power?
Good evening ... Lumberjack small rivers energy gears ...
Mechanical is considered that a spur gear typically loses 5% of the power in friction.
Well lubricated without bubbling, with helical teeth, you can climb up to 98% beyond, it becomes false advertising.
For greased racks, we can go down to 75%, for conical couples lubricated by bubbling, 85% (order of magnitude).
For irreversible wheels / worms, less than 40%.
What a gear "hates" is
speed et
sliding from one tooth to another, because the power dissipated is proportional to both.
I let you imagine at 10 rpm, or better, at 000 rpm, the consequences on the sliding speed ... then of a cascade of gears. The mechanism begins to resemble a radiator
Otherwise, indeed, the gearbox eats a lot of power: I also "militate" the hybrid-series with removal of the BdV because electronic conversions are much more flexible and efficient than gears.
but the 5% is not added up rigorously. Usually, there are 4 passages between the crankshaft and the axle, which means that the transmission efficiency is 0.95 ^ 4 = 81.45%
A further 0.8 is multiplied, which is the performance of the tires. 0.9 which is the efficiency of the bridge, 0.25 motor efficiency, some other 0.98 here and there for the efficiency of tripod joints ...
I did the calculation once, when we take everything into account, the fuel efficiency on the road (
to the wheel) is around 10%
On 10 L of gasoline 9 directly dissipated somewhere in the car, the remaining liter becomes kinetic energy, itself finally dissipated into the air pushed by the car ...