Engine construction and cycles

Question 1

bedplate

Answer 1

provides support, help put forces into the ship has to resist bending and provides alignment for the engine

Question 2

tie rods

Answer 2

they run from the bed plate into the cylinder block, clamps the whole engine together

Question 3

holding down bolts

Answer 3

used to hold the engine down using a clamping force, provides stiffness and alignment

Question 4

a-frame

Answer 4

has to resist forces being applied from the crosshead

Question 5

crank shaft

Answer 5

turns rociprocating motion into rotary motion. harness the tramendous force produced by the downward thrust of the pistons

Question 6

differences between 4 and 2 stroke

Answer 6

2 stroke has a crosshead which allows us to keep the piston rod vertical.

a 4 stroke has an intake valve a 2 stroke has scavenge ports.

a 4 stroke has rocker arms

a 4 stroke is an single casting, an entablature.

a 4 stroke does not need tierods

Question 7

purpose of the cam shaft

Answer 7

it is nessecerry to create the timings of the valves and fuel pumps which control the engine cycle. each valve or pump is attached to a cam follower which rises and falls as the cam rotates beneath it. the profile of the cam is designed to give the correct timings and speed to its corrosponding follower

Question 8

2 methods of driving a cam shaft

Answer 8

belt driven

gear driven

Question 9

function of the diaphragm and stuffing box

Answer 9

they provide a seal so that no oil and air get into the scavenge space and air getting into the crankcase