Final Drive Construction Flashcards
What are the main components of the final drive assembly?
Crown wheel Pinion Taper roller bearings Housing/casing Input flange
What is the purpose of the final drive?
Transmit drive through an angle of 90 degrees
Provide a gear ratio that reduces speed
Permit an additional and constant gear reduction
What are the 3 types of final drive gears?
Straight bevel
Spiral bevel
Hypoid gear
Why would you not use a bevel gear?
Noisy
What is the main difference between the hyoid gear?
Diameter increases up to 30% and offset by 1/5 which produces a stronger, larger gear
Where is the pinion positioned on lighter vehicles?
Below centre line
Where is the pinion positioned on heavier vehicles?
Above centre line
What is required to help cool worm drives?
Cooled sump
What are the 3 types of worm drive designs?
Overhead, under slung and hour-glass or hindley
What are the 2 ways to measure pre-loading?
Spring balance , pre-loading gauge
What are the 2 types of spacers
Rigid and ductile
Why is the rigid spacer simpler?
Replacing the seal does not affect the pre-load
What does the ductile spacer simplify?
Pre load setting
What must you do before adjustment to the pinion is carried out?
Apex of the pinion must coincide with the centre line of the crown wheel to avoid slipping
What is backlash?
Gap between pinion and crown wheel teeth
