190201f Crankshaft, Bearings and Related Component Fundamentals

Question 1

What are the 2 functions of the crankshaft

Answer 1

1. convert reciprocating motion of the piston to Rotary

2. drives the camshaft and engine accessories

Question 2

The relative position of the throws on q crankshaft are determined by the manufacturer, based on several factors:

Answer 2

number and arrangement of the cylinders
firing order
engine balance
main bearing loads

Question 3

on a four stroke engine how could you determine the number of degrees between the throws on a crankshaft?

Answer 3

720 ÷ number of cylinders = the degrees between the throws

Question 4

chemical treatment of the crankshaft surface and journals is called?

Answer 4

nitriding

Question 5

What are the two function of the crankshaft gear?

Answer 5

time the camshaft

transfer power to the accessories

Question 6

1. Most gasoline crankshafts are constructed of :

2. Most diesel crankshafts are constructed of:

Answer 6

1. cast iron

2. forged steel

Question 7

Common method used to harden diesel crankshaft surface and journals.

Answer 7

induction harding

Question 8

Why is the oil film crucial between the bearing and the shaft?

Answer 8

reduce the friction

carry away heat from the bearings and shaft

Question 9

Bearing should have this properties:

Answer 9

embeddability
conformability
fatigue resistance
corrosion resistance

Question 10

Friction bearing have three basic purposes:

Answer 10

reduction friction of moving parts
support and maintain alignment
durable, replaceable wear surface

Question 11

What are the two types of vibration dampers

Answer 11

rubber element type

viscous type

Question 12

How to clean a rubber element damper

Answer 12

hot soapy water and blow dry

Question 13

What should not be used to clean a viscous type

damper

Answer 13

hot tank

Question 14

Cross hatch angle should be

Answer 14

40 to 60 degrees

Question 15

When movement greater than 1/16” on a rubber element this could cause

Answer 15

damper will not function correctly
inertia mass could fly off
timing marks would not be accurate

Question 16

The number of degrees when the intake and exhaust valves are both open is referred to as:

Answer 16

valve overlap

Question 17

A running diesel engine operates with cylinder temperatures that reach _______ degrees and peak cylinder pressures averaging ________ psi.

Answer 17

3500 F (1926.7 C) 2000 psi (13789.5kPa)

Question 18

The relative position of the throws on a crankshaft are determined by the manufacture based on several factors, which are?

Answer 18

number and arrangement of the cylinders, firing order, engine balance and main bearing loads

Question 19

Gas crankshafts are usually?

diesel crankshafts are usually?

Answer 19

Cast

forged alloy steel

Question 20

List two purposes of the oil film between bearing and the crankshaft journal?

Answer 20

reduce friction,

carry away heat

Question 21

Friction bearing have 3 basic purposes?

Answer 21

reduce friction, support and maintain alignment ,

provide a durable replaceable wear surface

Question 22

What are the two types of vibration dampers commonly used on diesel engines?

Answer 22

rubber element

viscous

Question 23

any movement greater than 1/16” in the rubber element type damper indicates that the bond has broken. Once this has occurred:

Answer 23

the damper will not function properly
the inertia mass could fly off the hub during engine operation
timing marks on the inertia mass will be inaccurate