What transmits power from the starting RIMMS to the high speed reducing gear?

• A. Starter motor
• B. Clutch
• C. Drive shaft
• D. High speed gearbox

Answer: (D)

The starting device must couple its fast, low-torque output into the gear train that will drive the compressor and shaft system. The high speed gearbox is the component that actually transmits and converts that energy: it accepts the rapid input from the starting RIMMS and lowers the speed while increasing torque to feed the high speed reducing gear. The drive shaft is only the mechanical link, and the clutch mainly engages or disengages the connection; they don’t provide the necessary speed-to-torque transformation by themselves. The starter motor supplies the energy, but the rotation is transferred to the next stage through the gearbox, making the high speed gearbox the correct choice.