190303a Flashcards
What are the subdivision of a gear tooth?
Pitch line divides face & flank.
Centre line divides heal and toe
What is the largest and smallest part of a gear tooth?
The heel is the outside and the largest part of the gear tooth.
The toe is the inside and the smallest part of the gear tooth.
What is the root fillet and it purpose?
It is a slightly rounded fillet and it gives strength to the tooth. Prevents cracking.
There is a drive side and a coast side of a gear tooth what shape are the two sides?
Coast side is concaved and the drive is convex.
What dose the term path of power refer to?
The path of power trace method is use to determine witch gears are in use with in the power train.
What are the three diameters of a gear?
Outside, pitch & root diameters.
What steps do you take to determine circular gear pitch?
Pitch circle must be established.
Then exact centre of each gear tooth must be determined.
The distance between centre line to centre line is your circular gear pitch.
What characteristics must two meshing gears have with one another in order to work together?
They must have the same circular gear tooth pitch. This will give the gear set the greatest strength and max for can be delivered.
What is the the gap between two teeth and it’s purpose?
It is called clearance and it helps to maintain lubrication
What is backlash?
It is a space between two gears that exist for tooth expansion and lubraction
What are the characteristics of a non-hunting gear set?
Must be timed
Specific wear pattern
Pinion and crown teeth divide equally ex 3:1.
What are the characteristics of a partial non-hunting gear set?
Must be timed
Specific wear pattern
Two or three revolutions must be made before original mesh point is reached.
Pinion and crown don’t divide evenly. 3.50:1
What are the characteristics of a hunting gear set??
No timing
All teeth are used
No wear pattern
Pinion and crow divide unequally 3.3333:1
Explain a direct drive gear set?
Identical size gears in mesh.
Speed and torque are equal.
