Transmission

 

Just like in your family road car, F1 cars have a clutch, gearbox and differential to transfer the 800 bhp into the rear wheels. Although they provide the same function as on a road car, the transmission system in an f1 car is radically different

A good engine must be installed well to perform to its ultimate ability, and it must output its power to the wheels in the best way possible. The engine is connected to the flywheel, which is linked to the drive shaft via the clutch plates. The drive shaft goes into the gearbox, which is connected to the axles (and therefore the wheels) through the gears and differential.

 

Having explained how the gearbox works in my article, the next thing to consider is how to change between gears. This is done using the clutch. But why? Well, with the gear wheel on the end of the drive shaft rotating in the gearbox, it is not going to be easy to move it through the gears to meet up with another gear. Any attempt to do so will result in that annoying, grinding noise heard all too often from a poorly driven car! That noise is the noise of the rotating gear wheel on the drive shaft grinding against one of the gears in the gearbox - carry on with that, and you're going to be left with a gearbox full of metal shreds! Or worst!

 

This is why the drive train in a car incorporates a clutch. In F1, they are multi-plate designs that are designed to give enhanced engine pick-up, and the lightweight deigns with a small diameter mean that they have low inertia, allowing faster gear changes. Flying wheel on F1 car is just 10 centimeters in diameter. The drivers do not normally use the clutch manually, apart from moving off from standstill, during pit stop and in case of emergency or spin. They simply press a gear change selector lever behind the wheel to move to the next ratio. The on-board computer automatically cuts the engine, depresses the clutch and switches ratios in the blink of an eye.

In the world of the F1 semi-automatic gearbox, of course, there is no need for the driver to even think about this – everything is electronically controlled! All the driver is required to do is to pull paddle when he wants to change up or down a gear, and the electronics controlling the gearbox and clutch do the rest. The advantages here, over and above the fact that the driver can keep his hands on the wheel at all times, is that the whole process can be done in a split second (much quicker than a manual clutch could be operated) and also that the wear on the clutch pads is less because it is never held half-on, and so this increases reliability.
The engine and transmission of a modern Formula One car are some of the most highly stressed pieces of machinery on the planet.

Traditionally, the development of racing engines, transmissions and the rest of F1 car has always held to the rule of the great engineer Ferdinand Porsche who stated that the perfect race car crosses the finish line in first place and then falls to pieces. Although this is no longer strictly true - regulations now require engines to last five race weekends, and gearbox's four - designing modern Formula One engines remains a balancing act between the power that can be extracted and the need for JUST enough durability.
The start phase in Formula 1 is very important. Beginning and first highlight of every race. Decisive fractions of a second. So much is at stake during the first few hundred meters of a Formula 1 race today that some of the most sophisticated and secret engineering on the cars is been devoted to help a driver during those first couple of seconds, during which he attempts to get his car off the line and up to speed quicker than those around him on the grid. The prize was the order of cars into the first corner, which in today's racing so often dictates the order for the rest of the race. Of course, that was until year 2007!!! Previously the drivers could rely on highly sensitive and fast electronics during this critical phase - from 2008 no longer. With effect from this year, the regulations forbid the use of ANY start electronic assistance and traction control in race phase. With common ECU this is easily controlled by FIA. Sensitive handwork during the start is again in demand. And that should be taken literally, because in the F1 the commands to the gearbox and clutch are distributed by means of a steering wheel mounted paddles. Transmissions may not feature traction control systems, or devices that help the driver to hold the clutch at a specific point to aid getaway at the start of the race.

After abolishing all electronic help during the start phase Thomas Rudolf, engineer for clutch systems at ZF Sachs Race Engineering explained "We see the return to handwork from a technical view point with mixed feelings".
The ZF Sachs AG motorsport department equips the Formula 1 teams of Ferrari, Honda, Toyota and some other teams with clutches and shock absorbers.
With electronic control and help, the clutch got rid of surplus power with slips between carbon clutch plates. As a result, this important interface in the drive train was subject to extremely high loads, for up to two seconds and in exceptional cases even up to ten seconds and heated to temperatures in excess of 1000 degrees Celsius.
The engineer explains why: "In contrast to a normal car with a clutch pedal, the Formula 1 driver doesn't feel a pressure point with his paddle. He must REMEMBER in which paddle position the gear is engaged. It is a balancing act. Even top drivers like Michael Schumacher can slip the clutch for only a maximum of half a second as to help to pull away. This is not enough, and is only a quarter of the time that the electronic help function for pulling away demanded."
A few key figures illustrate these extreme loads that impact on the F1 clutch from ZF Sachs weighing no more than roughly 860 grams: the diaphragm springs apply 1.6 tons of pressure to the three clutch plates, and the tiny 100-millimetre titanium housing withstands temperatures of up to 700 degrees centigrade.
Does the new regulations therefore guarantee an easier time for the clutch? No. Because, where the human element is involved mistakes happen. If a driver misses the pressure point and releases too fast, the engine could stall, he disengages the clutch again, lets the engine revs skyrocket and tries to reengage the clutch again. Often, the whole process is repeated several times. As a result even higher loads and temperatures can occur. Even if such mistakes are not the rule, engineers who construct the clutch must make provision for them. That's why they have refrained from reducing the reserves released through the abolition of the electronics.

In fact the Sachs Formula 1 clutch of 2008, at the same overall dimensions as its predecessor, is even more efficient. The technicians reduced the clutch hub size of previous successful model, but anyway they gain more room for the stressed carbon disc friction faces. The diaphragm spring, which clamp the friction plates with a force of 1.6 tones, are produced from special steel alloy resistant to temperatures of up to 700 degrees Celsius. Also the tiny titanium housing with a diameter of around 100 millimeters is, thanks to an even further optimized machined contour, more robust. Sachs expects the component longevity to have increased by a factor of three. The housing is particularly stressed by engine vibrations. "Although the engines must last a two race-weekend, the relevant key data for us remains almost unchanged. The power units still rotate at 19,000 rpm and are actually lighter rather than heavier. And the lighter an engine is, more it vibrates, which wears out the clutch housing", explain Sachs engineer.

The new gearboxes that have to last for four races also have no influence on the clutch. From the technical point of view Formula 1 racers do not require a clutch to shift in the higher gears. The loads resulting from this have already been taken into account for years.

For safety reasons all cars must have a means of disengaging the clutch that is operable from outside the cockpit by marshals. This control is usually situated just ahead of the cockpit opening and is marked on the car's body by a red letter "N" within a white circle.

 

 

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