Millwright - Bearings 1 (Canada skilledtrades) Exam with verified detailed answers

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Millwright - Bearings 1 (Canada skilledtrades) Exam with || || || || || || || ||




verified detailed answers || ||




What is the approximate temp of the inner ring of a bearing if the housing is 80 degrees
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Celsius?

100-110 degrees Celsius || ||




Does new oil meet ISO cleanliness code for bearings?
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No

What happens to the oxidation rate of a petroleum based lubricant, when the temp
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increases from 55 degrees Celsius to 65 degrees Celsius?
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Oxidation rate doubles || ||




If no vibration can be detected on a bearing housing, can you safely assume that there is no
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harmful vibration present? || ||




No

What normal checks should you make on bearing with higher than normal amperage
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readings?

Temperature, vibration, lubricant, and noise || || || ||




What kind of noise should a good bearing make when heard through a stethoscope?
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A low purr
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What is built-in-contamination?
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Contamination in bearing from assembly process || || || || ||




Why is it important that the dimensions of bearing seats be within spec?
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Out of spec causes bearing distortion
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Why does a temperature of 150 degrees Celsius harm most bearings?
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Temperatures of 150 degrees Celsius will distort bearing || || || || || || ||




What is meant by the term "brinelling"?
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, 2


Impact denting of the race ways || || || || ||




What level should oil be on an anti-friction bearing running in an oil bath?
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Between 1/3 and 1/2 the way up the lowest ball or needle
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What are the two most common causes of vibration in bearings?
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Imbalance and misalignment || ||




What is the only reliable way to eliminate induced shaft currents?
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De-magnetize the rotor || ||




Does a temperature of 80 degrees Celsius harm the lubricant or the bearing?
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The lubricant
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What are 3 faults that may cause and be indicated by leaks at the joints in a bearing
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housing?

Damaged gasket, cracked housing, and loose cover bolts|| || || || || || ||




How does increase in temperature affect film strength of oil?
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It weakens it
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What type of lubricant film provides the least friction in a plain bearing?
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Full film ||




What 2 conditions OUTSIDE of a bearing housing can cause an increase in the operating
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temperature of a bearing? || || ||




Ambient temperature, and temperature of the product the shaft is in contact with
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Do bearing temperatures normally increase or decrease after re-lubrication?
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Increase

Can all harmful levels of vibration be detected by hand?
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No

How can bearing condition be monitored before it reaches last stages of deterioration?
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Vibration analysis ||




What do high amperage readings suggest about the condition of a bearing?
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