14/10/2011
Lotus Renault GP strategic partner Total regularly offers F1 news on its site, with information ranging from the relationship between fuel and F1 to interviews with their leading scientific delegate. This week we explore Total’s expertise in an area other than engine oils and fuels.
Banishing Friction
A transmission comprises two drive shafts that connect the gearbox to the rear wheels to “transmit” power from the engine. At each end of the shafts, tripod joints couple them to the gearbox and the wheels to enable the transmission of rotational movement despite the rocking of the suspension. To ensure that the metal surfaces slide smoothly against one another, to avoid them seizing up from friction and preventing rotation, these parts have to be lubricated, especially since an F1 car wheel can revolve nearly 3,000 times a minute at full speed. Using oil would require a heavy, bulky sump and is therefore out of the question. So to protect the transmission parts in the R31, the Lotus Renault GP team uses lubricating greases developed by Total.
Tailor-made by Total
Starting with synthetic base oils, Total engineers use polyurea thickeners and additives to obtain the ideal grease. The thickener ensures that very high rotation speeds are possible without excessive heating. In a passenger car, where gears are changed on the basis of engine torque, electronics ensure a smooth transition to higher gears. This is not the case in an F1 car, where torque is less important and the primary objective is to feed power to the wheels as quickly as possible. The grease used must therefore be able to lubricate effectively and instantly and offer strong resistance to high temperatures (temperatures can reach 900°C on the wheel-side because of the brake discs). Because lateral acceleration can reach up to 3.5 g in F1 racing, it must also adhere well to the metal parts in order to resist centrifugal force when the car turns. These challenges are met on racetracks worldwide thanks to Total’s teams.
But lubricity is not the only criteria when making a good F1 grease. Other properties, such as density, are also important. The ideal grease must have the lowest possible density to limit the car’s weight and be used in reduced volumes to ensure that the mechanical parts are as small as possible. With a total of one liter of grease on the car’s tripod joints, reducing density from 2.5 to 1.5 g/cm3 (closer to that of oil) means a one kilogram reduction in mass. This makes the car lighter and improves the position of its center of gravity.
When you’re trying to optimize performance, every little detail counts. To find out more on Total’s involvement with LRGP, click here
Credit: Lotus Renault GP (www.lotusrenaultgp.com)
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