Transmit power from prime mover to a shaft
Allows for variation in speed and power(torque)
Allows for changes between ahead and astern
1 of 21
What are the names of the gears attached to the prime mover and shaft
pinion-attached to prime mover
Wheel-attached to the shaft
2 of 21
Name the four types of gears used within the RN
Straight spur
Helical
Double Helical
Worm
3 of 21
State the disadvantages of a Straight spur gear
Can only be used in low speed areas and creates a lot of noise
4 of 21
State a disadvantage of a helical gear
Helical Gears create axial thrust necessitating the need for thrust bearings
5 of 21
What set of gears counter axial thrust
Double helical gears counter axial thrust by using opposing cut teeth to cancel out the forces created
6 of 21
what is the greatest ratio that can be sensibly achieved using a single reduction
15:1
7 of 21
What is an advantage of double gear reductions and how does it achieve this ?
Smaller gears can be used making the gearbox smaller, this is done by increasing the amount of pairs of meshing gears.
8 of 21
What is an advantage of double gear reduction-dual tandem and how is this achieved ?
is a symmetrical version of a double gear reduction halfling the load allowing smaller pinions to be used reducing the weight of the gear box.
9 of 21
What is the purpose of the shaft brake ?
Used to stop and hold the propeller shaft, gearing and power turbine whilst the gas turbine is idling.
10 of 21
State the brake application and release checks.
Brake application:
No fire risks are present, All brake pads are applied, shaft is stationary
Brake release:
No fire risks present, All pads are clear, shaft is turning
11 of 21
What is the purpose of the thrust block ?
Absorbs the forces created by the propeller and transmits them to the ships hull to move it ahead or astern
12 of 21
State the purpose of the turning gear.
Used to slowly turn the shaft and propeller for docking and maintenance.
13 of 21
Describe the FL cut in process
Carried out daily
checks the cut in pressure of the motor driven pump
In case oil pressure drops, due to gear driven pump failiure, below 18.5PSI the motor driven pump should activate.
14 of 21
What is the purpose of the plumber block and what are its main components?
It supports the weight of the shaft without absorbing any of its thrust.
main components:
Casing, Bearings, Journal pads, Oil cooler and dipstick.
15 of 21
What is the purpose of a bulk head gland ?
This creates a water tight seal between compartments that the shaft passes through without absorbing any thrust.
16 of 21
What is the purpose of the stern seal ?
Creates a water tight seal through the ships hull that the shaft passes through, has an inflatable seal in case of emergency/failure.
17 of 21
Name and state the purpose of the "A" brackets.
Intermediate and main A brackets
They support the weight of the shaft outside the ship.
18 of 21
Name the sections of the shaft starting closest to the gear box.
Thrust shaft, Intermediate shaft, Tail shaft.
19 of 21
What is the purpose of the SKF coupling ?
It allows the tail shaft to be separated from the intermediate shaft without leaving a flange.
20 of 21
State the advantages of a CPP
A hydraulic system provides the movement/change in angle to the blades allowing it to go astern without a reversible gearbox
21 of 21
Other cards in this set
Card 2
Front
What are the names of the gears attached to the prime mover and shaft
Back
pinion-attached to prime mover
Wheel-attached to the shaft
Comments
No comments have yet been made