Assignment - Shafting, Fits & Accessories. Flashcards Preview

Millwright 2nd Block > Assignment - Shafting, Fits & Accessories. > Flashcards

Flashcards in Assignment - Shafting, Fits & Accessories. Deck (21):
1


Keys are a.....


- Timing Device
- Shear Point

2


Key clearance should not exceed _____ of an inch.


- 0.002"

3


Rule of thumb for key width.


- Key should be about 1/4 the diameter of the shaft

4


When are a Pratt & Whitney key used?


- You use these keys when the hub slides back & forth on the shaft

5


Define a woodruff key code 1212


- 12 = 12/32, 12 = 12/8
3/8" wide and 1 - 1/2" inches long

6


What is the taper of a Gib head key?


- 1/8" taper per foot.

7


Gib heads should never be used in this type of hub.


Cast Iron hubs, hub could crack when driving in the key.

8


When should we use a chamfered key and seat?


Situation with heavy shock loads.

9


Other than some form of key, what is another form of torque transfer?


- Splines

10


In what direction do you lock the eccentric collar on a pillow block?


- direction of rotation.

11


Why do we machine a radius or fillet on a shoulder of a shaft?


- Additional strength

12


The two main stresses a shaft must stand up to?


- bending stress
- torsional stress

13


The force applied to a shaft by resistance to turn is some times called?


- Torsional shear stress

14


What is the recommended maximum distance between bearings on a line shaft?


- 8 feet

15


How much carbon steel does a 1018 shaft have?


0.18%

16


Stainless stell is divided into three groups, what are they, and which one is non magnetic?


- Ferritic
- Martensitic
- Austenitic - Non-magnetic

17


What are the three types of fits?


- clearance fit
- interference fit
- transitional fit

18


What diameter should a set screw be?


Same size as the key

19


The two types of keys that cannot have set screws are?


- tapered key
- woodruff key

20


The key that only relies on the fit between the key, the seat and hub. The key that locks the hub to the shaft.


Tapered gib key.

21


Bonus mark. What type of chisel would you use to cut a keyway in an emergency?


Cape Chisel