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46 Cards in this Set
- Front
- Back
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Proper level of lubricant in a rolling element bearing is |
Halfway up the lowest rolling element |
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Movement of oil in a wick feed oiler is by |
Capillary action |
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A measure of grease stiffness is referred to as |
Consistency |
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Thickeners for greases can be made from compounds that are classified chemically as |
Soaps |
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The system which offers advantages where there are a large number of lubrication points is the |
Centralized lubrication system |
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Why is is important not to allow the oil level in an oil bath lubrication system to go above the centerline of the lowest rolling element |
To avoid churning, which would produce extra heat |
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What are two disadvantages of a bottle lubricator |
Oil is not recirculated, but wasted It is restricted to uses where surface speeds are low |
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Can a wick feed lubricator be mounted below a bearing |
Yes |
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Should a constant level lubricator be mounted on the left or the right side of the housing if the rotation is clockwise |
Left side |
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What are four disadvantages of ring or chain oilers |
Ring oilers are limited to shafts under 4 inches Rings or chains can wear through and break without being noticed, leading to lubrication failure They only work on horizontal shafts They only work dependably on stationary equipment |
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What are two important functions of a sight glass on a lubrication system? |
To monitor the oil level To monitor the condition of the oil |
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What component should be added to a pressure lubricating system if the oil is exposed to temperatures above 55C |
A heat exchanger |
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What are three limitations of an oil mist system |
The oil must be kept above 20C to keep it in Suspension It can only be used where oil mist will not endanger health It is not suitable for high-temperature applications, as oil mist oxidizes more rapidly |
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What are three advantages of an air-oil system |
It pressurizes the bearing housings, which prevents contaminants from entering It consumes very little oil It promotes longer bearing life by delivering cool, clean oil in the correct amount |
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Where would a block lubricating system normally be used |
On large stationary engines and reciprocating compressors |
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Why should oil samples be taken at regular intervals for testing |
To establish a performance trend for the oil and a wear rate for the machine |
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Is it best to take an oil sample immediately after a machine has been running at its normal operating temperature or after it has cooled down? |
Immediately after running, to establish a wear rate for the machine |
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Does the number of parts per million on a spectroscopy report indicate the actual amount of wear on components |
No |
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How is the wear rate of components determined |
It is based on a change in the spectroscopy numbers |
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What does the silicone particle count indicate? |
The amount of dirt ingested through the seals and breather |
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How can you tell if the particle count in a lab report is excessive or not? |
By comparing the count to the target cleanliness levels specified by the manufacturer |
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Give three reasons for on-line flushing |
To remove contaminants introduced into the system during assembly To remove preservatives To reduce the particle count in new oil to the manufacturers specifications |
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What are the two main safety concerns when handling or storing lubricants |
Cancer Fire |
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Does new oil meet manufacturers recommended standards for bearings |
No |
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What are two advantages in sending used oil for re-refining |
It prevents possible contamination of the environment It provides a supply of top-quality oil |
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What is a grease |
Grease is a liquid lubricant mixed with a thickener |
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How does a grease thickener work |
The thickener acts like a sponge to hold the lubricant and also controls the flow of the grease to the area to be lubricated |
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What is the drop point referring to in grease |
This is the lowest temperature at which the lubricant begins to drip from a grease |
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What is one of the oldest grease thickeners used |
Soap |
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Why should you not use grease with different thickeners |
Mixing results in a softer grease with a Lower useable operating temperatures |
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What does grease consistency depend on |
Consistency depends on type of thickener, quantity of thickener and temperature |
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What is the purpose of having EP additives in grease |
To prevent damage from welding at the tips of asperities on the loaded surfaces |
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What is an advantage of a single point grease application system |
Simple (no pumps or metering valves), compact (no grease lines) and inexpensive |
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What is a disadvantage of a single point grease application system |
When there is a large number of lubrication points, in which case more time is required to monitor the process |
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What types of grease cups are considered automatic |
Spring loaded and electric timer style |
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What is necessary before injecting grease into a grease nipple |
Clean the grease fitting thoroughly before attaching the grease gun |
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Give two advantages of a central lube system |
Eliminates the risk of contamination from dirt on a grease gun nozzle or dirt getting into a grease cup when you refill it Metering valves ensure that the correct quantity of lubricant is applied |
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How full should the housing be for a grease-lubed bearing |
Housings should not be more than 1/3 full |
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What are the three types of solid lubricants often used in industry |
Graphite PTFE Molybdenum disulphide |
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What colour is graphite type solid lubricant |
Grey black |
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Which solid lubricant has the greater load-carrying capacity, graphite or telfon |
Graphite |
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Which lubricant may be used where oil and grease are not adequate |
Solid lubricants |
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Which is the best one to carry away heat (oil, grease, solid lubricants |
Oil |
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Which is the best one to flush away contaminants (oil,grease,solid lubricants? |
Oil |
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Which is the best one to use if you need it bonded to a surface permanently (oil grease, or solid lubricants) |
Solid lubricants |
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What is the recommended level of oil in a bearing |
No higher than halfway up the lowest rolling element |
