HET 4 GEARING Flashcards
GEARING PRINCIPLES 190401C
What are components of a gear tooth?
Face, Flank, Heel and Toe
Is the concave side or the convex side the drive side?
Convex side is a drive side
The larger end of a gear is the?
a) heel
b) toe
c) face
d) flank
Heel
What is special about the root fillet area?
Its rounded, to give strength
When the is off the throttle and is in a coasting moment, what happens to the drive and driven side of a gear?
The opposite side becomes the driven, concave is drive and convex is driven
What three circles are measurable in on a gear?
Root
Pitch
Outside
What needs to be found before the circular gear pitch can be determined?
Pitch circle
If the gears in mesh have the same circular gear tooth pitch, what does it achieve?
Greatest strength
The clearance between the root and tooth tip of two gears is there for what reason?
To provide a space for lubrication
Why are gears not installed in tight contact?
No room for expansion during operation
What tool is used to measure backlash?
Dial indicator
When gears have run together for a long time what can happen?
change in tooth profile/shape, gears have worn into eachother
What types of timing are possible with gears?
Hunting, Non-Hunting and Partial Non-Hunting
Why are timing marks important in a non-hunting gear set?
The timing marks must line up - proper timing - longer service life
What type of timing design would a gear set be if the ratio is 5:1?
Non-hunting
What type of timing design would a gear set be if the ratio is 8.5:1?
Partial non-hunting
What type of timing design would a gear set be if the ratio is 3.89:1?
Hunting
Describe hunting gear sets?
No specific wear pattern is created, every tooth in one gear will touch every tooth in the other gear, no timing
If a few teeth on one gear constantly mesh with only a few teeth on another gear, the gears are timed or not?
Timed - non or partial non hunting
Which type of gear timing has the most distinctive wear pattern?
Non-hunting
When two external gears are in mesh what is produced?
A reverse
What is the speed difference between input and output gears when they are identical size?
No speed differences
Why is path-of-power important to understand when looking at gears?
Helps determine gear ratios, troubleshoot faults