What type of lubrication system is used in large turbines, and where is the oil distributed?

In large turbines, a pressurized circulating oil system is utilized to ensure adequate lubrication. This system is designed to distribute oil not just to the bearings, but also to various critical components of the turbine. The use of pressurized oil allows for a more efficient and controlled delivery of lubrication, which is essential to maintain optimal operating conditions and prevent wear and overheating.

The design of the pressurized circulating oil system typically includes an oil reservoir, a pump to circulate the oil, and a network of piping that directs the oil to multiple points of the turbine such as bearings, gears, and sometimes even to the seals and other moving parts. This extensive distribution helps maintain system integrity and prolongs the life of the turbine by minimizing friction and providing cooling through the movement of oil.

The other lubrication systems mentioned do not offer the same level of efficiency or protection. A gravity-fed system would be less effective in maintaining oil flow under varying operating conditions. A simple drip feed system only targets turbine bearings, failing to lubricate other vital components necessary for proper function. Self-lubricating internal systems can be effective for some smaller mechanisms but generally lack the capability or range necessary for larger, high-speed machinery, like turbines.