9.1 State TWO functions of an automatic gearbox in a motor vehicle - NSC Mechanical Technology Automotive - Question 9 - 2020 - Paper 1
Question 9
9.1 State TWO functions of an automatic gearbox in a motor vehicle.
9.2 State the function of the brake bands in the automatic gearbox.
9.3 State TWO disadvantages... show full transcript
Worked Solution & Example Answer:9.1 State TWO functions of an automatic gearbox in a motor vehicle - NSC Mechanical Technology Automotive - Question 9 - 2020 - Paper 1
Step 1
State TWO functions of an automatic gearbox in a motor vehicle.
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Answer
The automatic gearbox relieves the driver of clutch and gearshift operation, allowing for easier driving.
It transmits the drive from the engine to the wheels, adjusting according to load and engine speed.
Step 2
State the function of the brake bands in the automatic gearbox.
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The brake bands enable the annulus to come to a stationary position, allowing for a change to another gear ratio.
Step 3
State TWO disadvantages of an automatic gearbox in a motor vehicle.
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Answer
The automatic gearbox is generally more expensive to manufacture compared to manual gearboxes.
If a car with an automatic transmission needs to be towed for a longer distance, the propeller shaft must be removed, which can be inconvenient.
Step 4
State TWO advantages of a transmission control unit in an automatic transmission system.
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It enhances fuel economy by optimizing gear changes for efficiency.
It improves the overall vehicle handling by providing more precise control over the transmission system.
Step 5
Name TWO components in an epicyclic gear train of an automatic gearbox, which engage and disengage the different components to obtain different gear ratios.
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Answer
Brake bands.
Multi-disc clutches.
Step 6
Explain how the locking sequence of the epicyclic gear train is achieved.
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The locking sequence is achieved by the pressure of the oil from the oil pump, which directs the oil onto the hydraulic piston, engaging the necessary components.
Step 7
What is the main purpose of the control valve body in an automatic gearbox?
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The control valve body directs oil pressure to activate the hydraulic piston, ensuring that the correct gear ratio is selected based on load and speed.
Step 8
Explain the operation of the torque converter in an automatic transmission.
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The torque converter functions by using a pump that draws fluid into the curved fins of the turbine (vortex action). The fluid circulates around the turbine veins, producing torque. As the pump spins, it directs the fluid to engage with turbine blades, increasing torque to the transmission while allowing for fluid flow, effectively multiplying the available torque.
