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WORM GEAR EXAMINATION QUESTION | |
V. Ryan © 2003 | |
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The system opposite is used to control a set of traffic lights. The mechanism involved includes a motor which drives a worm gear round, turning a wormwheel and the attached cam. As the cam rotates it hits a micro switch which turns on a light |
If the cam turns at one rev per minute (rpm) and the wormwheel has 110 teeth, how fast does the motor rotate? |
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First work out the gear ratio: | |
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The worm gear always rotates at a faster rate than the wormwheel. RPM is 110 X 1 = 110 rpm (motor rotates 110 times per minute) The worm gear and motor rotates 110 times to every single rotation of the wormwheel. |
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