EXAMINATION QUESTION - GEARS
V. Ryan © 2006
The machine seen below is a power hacksaw used for cutting large section metals. It is powered by a motor. However, some motors tend to rotate at very high speeds making the power hacksaw cut far too quickly, over heating the blade. This will eventually snap and damage the material being cut. |
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1. List two advantages of controlling the speed of a motor on any machine. | ||
ADVANTAGE 1: | ||
ADVANTAGE 2: | ||
POSSIBLE ANSWERS | ||
ADVANTAGE 1: If the speed of the motor can be controlled the final output speed of the machine can be controlled. |
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ADVANTAGE 2: Different materials are cut and shaped at different speeds. Controlling the speed of the motor means that a range of materials can be cut/shaped by the machine. |
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2. The gear system shown below is to be added to the motor so that the speed of the power hacksaw can be controlled. |
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Calculate the velocity ratio of gears A and B | ||
POSSIBLE ANSWER | ||
3. Calculate the RPM (revolutions per minute) of gear B | ||
POSSIBLE ANSWER | ||
4. What is the speed (RPM) of gear C ? | ||
POSSIBLE ANSWER | ||
4. What is the speed (RPM) of gear C
? The speed of gear C is the same as gear B because they are fixed together and rotate teogether. |
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5. Calculate the velocity ratio of gear D | ||
POSSIBLE ANSWER | ||
6. Calculate the RPM (revolutions per minute) of gear D | ||
POSSIBLE ANSWER | ||
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