Lobe blowers

Question 1

Is a lobe blower a

-High pressure, Low flow
-Low pressure, High flow
Or neither

Answer 1

It is a low pressure high flow machine

Question 2

What is the common operating pressure differential for a lobe blower?

Answer 2

10-15 psi

Question 3

Does a lobe blower produce pressure?

Answer 3

No, it moves a volume of air from the inlet to the outlet and continues stuffing air into the discharge sump which builds the pressure.

It does not produce any pressure, it simply moves air.

Question 4

Where are the small clearances found on a lobe blower?

Answer 4

Between the rotors

Between the rotor tips and casing

Between the ends of the impellers rotors and the end plates

Question 5

What are the 2 types of 3 lobe rotor designs?

Answer 5

Helical cut lobes (gradually engaging)

Straight cut lobes

Question 6

Why is a cycloidal blower not a lobe blower?

Answer 6

It has a built in pressure ration.

Question 7

Will a 2 lobe or 3 lobe flow more gas per horsepower?

Answer 7

A 2 lobe will flow more gas per horse power.

Question 8

What are the 7 main parts of a lobe blower?

Answer 8

1. Impellers (rotors)
2. End plates (head plates)
3. Casing or cylinder
4. Bearings
   
   • normally anti friction bearings there is no inherent thrust developed by a 2 lobe blower but it still needs thrust bearings to set the axial position
5. Timing gears (straight spur or helical)
6. Oil reservoir
   
   • Usually found only on the timing gear end of the casing and the bearings and gears use the splash method to lubricate gears and bearings.
7. Oil seals