This pump is design to supply fuel to a burner that can have pressures above 7000 psi. Also the burner requires fuel flow of appox. 380 lbs/sec ( works out to about 2400 gpm).The drive train spins the second stage platter 1.5 times faster then the first stage platter. The bleved gears is a 1 to 4 increase and this is the speed of the first stage platter.
The third screen shot is how the pump fits into the over all fuel handling system.