In jet aircrafts where are the alternators, how are they connected to the jet engines? Is it using belts? Are they on the wings?
no, aircraft design is for extreme reliability. They'll be direct driven through variable speed drive as described in second link above.I dont... Is it belt driven?
I looked in those P&W cutaways for a gear driven shaft for auxilliaries, couldn't find one with cursory search.How can the engine remain airtight in the middle if it has some sort of gear to connect to the outside?
http://www.geaviation.com/education/vocabulary.html [Broken]Accessory Drive
The accessory drive section is attached to the outside bottom or side of the engine and is where all the mechanically-driven components are mounted to the engine. This section takes mechanical energy from the engine to power the engine and aircraft accessories mounted to the accessory gearbox.
The variable speed drive is not in the pressurized part of the engine. There is usually a radial drive shaft (with a gear drive) between one of the engine rotors and a unit mounted on the outside of the engine casing. The constant speed drive would be inside the external unit. This also drives the engine fuel and oil pumps, etc.I can't understand how the engine shaft will connect to a constant speed drive unit gear that then will link to the alternator