Cams Flashcards
1
Q
What are the four parts in a cam?
A
- follower
- camshaft
- circular cam
- crank
2
Q
What does a cam do?
A
Turns rotary motion into reciprocating motion
The follower move up and down whilst the cam rotates
3
Q
Define dwells
A
Remains stationary
4
Q
What happens in a pear shaped cam?
A
- The follower remains stationary for half of the cycle
- Pushed up when cam approaches
- As the point passes, the follower falls and then dwells again
5
Q
What happens in eccentric cams?
A
- circular
- Off-Centre rotating shaft
- Rise and fall produced are symmetrical
6
Q
What happens in Snail/drop Cam?
A
- Follower dwells for first 120* of the cycle or so
- Slow lift/rise
- Sudden drop
7
Q
Evaluate knife followers
A
- Sharp point
- Low friction
- Wear quickly
8
Q
Evaluate roller follower
A
- Replaces sliding motion between cam and follower from sliding to rolling motion.
- Reduces wear
9
Q
Flat followers
A
- Great under load or where space is limited
- high friction and not very accurate
