7.12 Flashcards
What is used to change direction on transmissions?
Sprockets or bi-planar blocks.
Where can chains be found in?
Control column installations
Aileron and elevator controls
Trim control systems
What chains are generally used for aircraft purposes?
Simple Roller type.
What standards are chain assemblies produced to?
Society of British Aircraft Constructors (SBAC)
What should a proof load for a chain be?
1/3rd of the minimum breaking load.
What is different between normal chain and non-reverse chains?
Every second outer plate is extended in one direction to break up the symmetry.
What should chains be cleaned with if elongation through wear is suspected?
Immersed in paraffin.
What needs to happen if the extension of a cable is in excess of 2% on any section?
The whole run replaced.
What is done after a chain has been cleaned?
Thoroughly soaked in appropriate oil.
What is done if a chain is not required for immediate use after cleaning?
Carefully coiled and wrapped in grease proof paper.
What is the most commonly used gear type?
Spur gear.
What is an advantage of a helical gear over a spur gear?
Transmit higher forces and run more quietly.
What angles can bevel gears be used up to?
180 degrees.
Why are worm gears advantageous?
Provide higher mechanical advantage without back loads being able to drive system in reverse.
What is the general purpose of backlash on gears?
Prevents gears from jamming and making contact on both sides of their teeth simultaneously.
