Accessories

Question 1

What do accessories do

Answer 1

Provide power

Question 2

Examples of accessories driven

Answer 2

Starter motor
Fuel control unit
Engine oil pumps
Tacho generator
Alternator/Generator
Centrifugal breather

Question 3

Several non driven

Answer 3

Scanvenge filter
Drain plugs
Oil temperature bulbs
Magnetic plugs

Question 4

The drive for the accessory units are typically taken from

Answer 4

Rotating shaft
Via internal gearbox
To an external gearbox

Question 5

What do spline and serrated drives do

Answer 5

Method of keying together rotating components

Transmit high power and allow easy fitting and removal

Question 6

Spline drive

Answer 6

Integral feather key machined on a shaft or in a hub to provide a sliding fit

Question 7

Serrated drive

Answer 7

Uses triangular projections
Mainly used on quill drives

Question 8

Purpose of internal gearbox

Answer 8

Made from aluminium
Dictated by the difficulties of bringing a driveshaft racially outwards a d the space available within the engine core

Question 9

Purpose of external gearbox

Answer 9

Made from magnesium to reduce GTE weight
Contains the drives for the accessories

Question 10

Purpose of the gears

Answer 10

Transimt the drive to each accessory
All gears meshed are designed with a HUNTING TOOTH - makes sure the same teeth don’t always continuously hit each other = spreads wear evenly