Lecture 5

Question 1

When does vibration come from in rotation masses?

Answer 1

Vibration occurs when the centre of mass does not coincide with the axis of rotation i.e. there is eccentricity ‘e’ between the centre of mass and the axis of rotation creating a centrifugal force

Question 2

What are the positive attributes of vibrations?

Answer 2

Informative physical feedback

Controlled agitation:
	Pile drivers
	Physiotherapy
	Cleaning
	Compaction
        Sieving

Question 3

What are the negative attributes of vibrations?

Answer 3

Increased bearing wear

Noise

Heat

Material fatigue

Decreased resolution in precision systems

Potential physical discomfort

Passive transmission to other systems

Question 4

What can change the balance of a system?

Answer 4

Erosion

Build up of contaminants

Poor casting with air pockets

Bearing wear

Loss of balancing components