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Wind Energy Engineering

Instructions:

Answer 10 questions in 15 minutes.
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Match each statement with the correct term.
Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.

1. How many planets are usually in a planetary gear?
Three.
It has more than one input and one output. Its size for the same power is smaller than the other gears. The input and output shafts are aligned.
The torque on the rotor shaft is larger (because its speed is less)
It increases the angular speed of the rotor shaft to an appropriate value for the generator

2. What is the main role of a gearbox in a wind turbine?
It increases the angular speed of the rotor shaft to an appropriate value for the generator
The gear ratio is the ratio of the number of teeth between two mating gears; it is usually the output to the input ratio - for example - 1 to 5 - meaning that the output gear has 5 times more teeth than the input gear.
No
In a spur gear - the teeth are parallel to the gear shaft. In helical gears - they are at an angle (this shows clearly when one looks at a gear at a direction perpendicular to the shaft direction).

3. What is the other name for a planetary gear?
Epicyclic gear.
The torque on the rotor shaft is larger (because its speed is less)
It increases the angular speed of the rotor shaft to an appropriate value for the generator
Normally gearboxes reduce speed (and sometimes are called speed reducers). In a wind turbine - they increase the speed

4. Can a worm gear be used in a wind turbine?
No; worm gears only reduce the angular speed.
No
It has more than one input and one output. Its size for the same power is smaller than the other gears. The input and output shafts are aligned.
Three.

5. What is the gear ratio?
The gear ratio is the ratio of the number of teeth between two mating gears; it is usually the output to the input ratio - for example - 1 to 5 - meaning that the output gear has 5 times more teeth than the input gear.
Normally gearboxes reduce speed (and sometimes are called speed reducers). In a wind turbine - they increase the speed
It has more than one input and one output. Its size for the same power is smaller than the other gears. The input and output shafts are aligned.
Epicyclic gear.

6. What is the advantage of a planetary gear?
No
It increases the angular speed of the rotor shaft to an appropriate value for the generator
In a spur gear - the teeth are parallel to the gear shaft. In helical gears - they are at an angle (this shows clearly when one looks at a gear at a direction perpendicular to the shaft direction).
It has more than one input and one output. Its size for the same power is smaller than the other gears. The input and output shafts are aligned.

7. What is the difference between a spur gear and a helical gear?
No; worm gears only reduce the angular speed.
It increases the angular speed of the rotor shaft to an appropriate value for the generator
In a spur gear - the teeth are parallel to the gear shaft. In helical gears - they are at an angle (this shows clearly when one looks at a gear at a direction perpendicular to the shaft direction).
No

8. In a gearbox of a wind turbine - which is larger: the torque on the rotor shaft or the torque on the generator shaft?
In a spur gear - the teeth are parallel to the gear shaft. In helical gears - they are at an angle (this shows clearly when one looks at a gear at a direction perpendicular to the shaft direction).
The torque on the rotor shaft is larger (because its speed is less)
Normally gearboxes reduce speed (and sometimes are called speed reducers). In a wind turbine - they increase the speed
No

9. Do all the gears have the same gear geometry?
Epicyclic gear.
No
It increases the angular speed of the rotor shaft to an appropriate value for the generator
Three.

10. What is the main difference between the gearbox in a wind turbine and one in any other machine?
No
Normally gearboxes reduce speed (and sometimes are called speed reducers). In a wind turbine - they increase the speed
The gear ratio is the ratio of the number of teeth between two mating gears; it is usually the output to the input ratio - for example - 1 to 5 - meaning that the output gear has 5 times more teeth than the input gear.
In a spur gear - the teeth are parallel to the gear shaft. In helical gears - they are at an angle (this shows clearly when one looks at a gear at a direction perpendicular to the shaft direction).