4BE3 U1 C2 Review
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Questions and Answers

What is the primary location of wear in a bearing?

  • When the shaft is rotating at a constant speed
  • During stopping and starting periods (correct)
  • When the shaft is rotating at high speed
  • When the shaft is not rotating at all
  • What is the purpose of the oil film in a shaft bearing?

  • To increase the friction between the shaft and the bearing
  • To reduce the pressure on the bearing
  • To reduce the temperature of the bearing
  • To separate the shaft from the bearing surface (correct)
  • What is the main advantage of using white-metal alloy in sleeve bearings?

  • It is very hard and resistant to wear
  • It is highly corrosive
  • It is soft and can conform to load conditions (correct)
  • It is very expensive
  • What is the purpose of the oil ring in a ring-oiled bearing?

    <p>To pick up oil from the reservoir and drag it up through the bearing slot</p> Signup and view all the answers

    Why are grooves in the pressure area of a bearing considered harmful?

    <p>They disrupt the oil film and reduce the size of the pressure area</p> Signup and view all the answers

    What is the primary function of the feeding device in a sleeve bearing?

    <p>To supply oil to the bearing at regular intervals</p> Signup and view all the answers

    What happens to the oil film as the shaft speed increases?

    <p>It becomes thicker due to the increased pumping action of the shaft</p> Signup and view all the answers

    What is the purpose of chamfering or rounding corners in bearings?

    <p>To prevent scraping of the oil from the shaft</p> Signup and view all the answers

    What is the main advantage of using a continuous oil supply in a bearing?

    <p>It ensures a smooth and even distribution of lubricant</p> Signup and view all the answers

    What happens to the shaft as it begins to rotate in a bearing?

    <p>It rolls up the side of the bearing</p> Signup and view all the answers

    What is the primary purpose of grooves in bearings?

    <p>To distribute lubricant along the shaft</p> Signup and view all the answers

    Where should the lubricant application point be located in a bearing?

    <p>In a portion of the bearing that is not under pressure</p> Signup and view all the answers

    What is a common sign of a failing bearing?

    <p>A rise in operating temperature</p> Signup and view all the answers

    What is the purpose of water cooling in bearings?

    <p>To prevent excessive heat from developing in the bearing</p> Signup and view all the answers

    How can emergency cooling of a hot sleeve bearing be achieved?

    <p>By increasing the supply of oil</p> Signup and view all the answers

    What happens when water is applied directly to a hot bearing?

    <p>The bearing cap may suddenly shrink or distort</p> Signup and view all the answers

    What type of force is exerted on a bearing due to the weight of the shaft?

    <p>Radial force</p> Signup and view all the answers

    What is the purpose of chamfering or rounding off sharp edges in bearings?

    <p>To prevent scraping of the lubricant from the shaft</p> Signup and view all the answers

    Why is it important to monitor the temperature of large bearings in critical machinery?

    <p>To prevent overheating of the bearing</p> Signup and view all the answers

    What is the purpose of an auxiliary groove in a bearing?

    <p>To improve distribution of the lubricant</p> Signup and view all the answers

    What is the primary cause of radial forces on bearings?

    <p>Weight of the shaft</p> Signup and view all the answers

    What is the term used to describe forces parallel to the axis of the shaft?

    <p>Thrust force</p> Signup and view all the answers

    What type of bearing is designed to handle axial thrust?

    <p>Thrust bearing</p> Signup and view all the answers

    What is the purpose of a thrust bearing?

    <p>To prevent the shaft from moving in an axial direction</p> Signup and view all the answers

    What type of lubrication is used in a collar thrust bearing?

    <p>Boundary lubrication</p> Signup and view all the answers

    What type of bearing does not permit metal-to-metal contact and establishes oil wedges to carry the entire load?

    <p>Tilting pad bearing</p> Signup and view all the answers

    What is the primary advantage of antifriction bearings over other types of bearings?

    <p>They have lower friction force</p> Signup and view all the answers

    What is the purpose of the separator in an antifriction bearing?

    <p>To prevent the rolling elements from coming into contact with each other</p> Signup and view all the answers

    What type of antifriction bearing has tapered rolling elements?

    <p>Tapered roller bearing</p> Signup and view all the answers

    What is the term used to describe the bearing surfaces in a tilting pad thrust bearing?

    <p>Pads</p> Signup and view all the answers

    What is the maximum amount of grease that should be added to an antifriction bearing after cleaning?

    <p>One-third full</p> Signup and view all the answers

    What is the primary cause of antifriction bearing failure, even with proper maintenance and lubrication?

    <p>Metal fatigue</p> Signup and view all the answers

    What is the effect of a hard mass forming within the bearing due to poor lubricant quality?

    <p>The bearing will wear excessively</p> Signup and view all the answers

    What is the result of pressing a bearing onto a shaft with uneven force application?

    <p>The bearing race will crack or split</p> Signup and view all the answers

    What is the maximum operating temperature that antifriction bearings can generally withstand?

    <p>120°C</p> Signup and view all the answers

    What is the result of misalignment of a shaft in an antifriction bearing?

    <p>Uneven loading of the bearing</p> Signup and view all the answers

    What is the main purpose of lubrication in antifriction bearings?

    <p>To protect the surfaces of the balls, rollers, and raceways from corrosion</p> Signup and view all the answers

    Why is oil preferred for lubricating antifriction bearings in high-speed applications?

    <p>Because it produces less heat due to churning or displacing the lubricant</p> Signup and view all the answers

    What is a potential problem with overfilling a bearing with grease?

    <p>The bearing may overheat and experience loss of lubricant</p> Signup and view all the answers

    What is the purpose of the seals in an antifriction bearing?

    <p>To prevent the entrance of dirt or other impurities into the bearing housing</p> Signup and view all the answers

    Why is grease preferred for lubricating antifriction bearings in applications where speeds are moderate and temperatures are not extreme?

    <p>Because it is less likely to be flung out or leak from the bearings</p> Signup and view all the answers

    What is a factor that determines the type of grease to use in an antifriction bearing?

    <p>The shaft speed and exposure to moisture</p> Signup and view all the answers

    What is a consequence of mixing different types of grease in an antifriction bearing?

    <p>The bearing will experience reduced lubrication effectiveness</p> Signup and view all the answers

    Why is it important to know how much grease to add to an antifriction bearing?

    <p>To prevent overfilling and premature bearing failure</p> Signup and view all the answers

    What is the purpose of the lubricating film in plain or shell bearings?

    <p>To separate the surfaces and reduce friction</p> Signup and view all the answers

    Why is steam cylinder oil sometimes necessary for lubricating antifriction bearings?

    <p>Because it is necessary for high operating temperatures</p> Signup and view all the answers

    What is a factor that determines how often bearings need to be lubricated?

    <p>Operating environment</p> Signup and view all the answers

    Why is it important to warm up equipment before adding grease?

    <p>To distribute the grease throughout the bearing</p> Signup and view all the answers

    What is the purpose of removing the drain plug before adding new grease?

    <p>To purge old grease from the bearing</p> Signup and view all the answers

    What is the benefit of using an automatic lubricator?

    <p>To ensure worker safety and correct lubrication</p> Signup and view all the answers

    How often does an oil-lubricated bearing typically need to be cleaned?

    <p>Annually</p> Signup and view all the answers

    What is the first step in cleaning a bearing without dismantling it?

    <p>Remove dirt from the outside of the bearing</p> Signup and view all the answers

    What should be done after adding new grease to a bearing?

    <p>Allow the machine to continue running</p> Signup and view all the answers

    What happens to excess grease after adding new grease to a bearing?

    <p>It is expelled through the open drain plug</p> Signup and view all the answers

    What should be done to the end of the grease gun before attaching it to the fitting?

    <p>Wipe it clean with a rag</p> Signup and view all the answers

    What is the purpose of a single point automatic lubricator?

    <p>To supply lubricant to a single point at a set time</p> Signup and view all the answers

    What is the recommended method to remove a bearing from a shaft?

    <p>Using a bearing puller</p> Signup and view all the answers

    What should be done to the bearing after it has been removed from the shaft?

    <p>Soak it in solvent for 12 to 16 hours</p> Signup and view all the answers

    What is the purpose of dipping the bearing in rust preventer and wrapping it in greaseproof paper?

    <p>To store the bearing</p> Signup and view all the answers

    Why should the shaft or housing be absolutely clean before installing a bearing?

    <p>To ensure the bearing can be pressed into place without scoring or scratching</p> Signup and view all the answers

    What is the ideal temperature for expanding a bearing to be installed on a shaft?

    <p>Between 80 and 100°C</p> Signup and view all the answers

    What should be done to the bearing after it has been heated to the ideal temperature?

    <p>Slide it onto the shaft quickly</p> Signup and view all the answers

    What should be checked for after the bearing has been cleaned and lubricated?

    <p>All of the above</p> Signup and view all the answers

    Why should special heat resistant gloves be used when installing a bearing?

    <p>To prevent contamination of the bearing</p> Signup and view all the answers

    What is the purpose of the temperature sensor in the induction heater?

    <p>To ensure the bearing is at the set temperature</p> Signup and view all the answers

    What should be avoided when dismantling a bearing?

    <p>Hammering directly on the inner or outer race</p> Signup and view all the answers

    What is the primary characteristic of boundary lubrication?

    <p>A microscopic film of lubricant separates the surfaces</p> Signup and view all the answers

    What type of lubrication is also known as flood lubrication?

    <p>Fluid film lubrication</p> Signup and view all the answers

    What is the critical factor in boundary lubrication at slow speeds and heavy loads?

    <p>The &quot;oiliness&quot; or film strength of the lubricant</p> Signup and view all the answers

    Under what conditions should solid lubricants be used?

    <p>Under special conditions</p> Signup and view all the answers

    What is necessary for fluid film lubrication to occur?

    <p>The bearing clearance space is completely filled with oil and the moving surface is in continual motion</p> Signup and view all the answers

    What is the result of a rapidly revolving shaft in a turbine or engine main bearing?

    <p>The shaft floats on a film of oil</p> Signup and view all the answers

    What is the primary factor that determines the type of lubrication used in a bearing?

    <p>Load and speed</p> Signup and view all the answers

    What is the result of metal-to-metal contact between the surfaces in a bearing?

    <p>Increased friction</p> Signup and view all the answers

    What is the minimum condition required for fluid film lubrication to occur?

    <p>The bearing clearance space is completely filled with oil</p> Signup and view all the answers

    What is the purpose of the lubricant film in boundary lubrication?

    <p>To reduce friction by wetting the surfaces</p> Signup and view all the answers

    What is the characteristic of grease that makes it suitable for use in slow speed and heavy load applications?

    <p>Greater wetting ability than conventional oil</p> Signup and view all the answers

    What is the condition required for the shaft to float on a film of oil in fluid film lubrication?

    <p>The shaft is rotating above a certain minimum speed</p> Signup and view all the answers

    What is the primary factor that determines the effectiveness of fluid film lubrication in a shaft bearing?

    <p>Pumping action of the rotating shaft</p> Signup and view all the answers

    Why is the white-metal alloy used in sleeve bearings?

    <p>It is highly corrosion-resistant and can conform to load conditions</p> Signup and view all the answers

    What is the purpose of the oil ring in a ring-oiled bearing?

    <p>To pick up oil from the reservoir and drag it up through the bearing slot</p> Signup and view all the answers

    What happens to the oil film as the shaft speed decreases?

    <p>It becomes thinner and less effective</p> Signup and view all the answers

    What is the purpose of grooves in the non-pressure area of a bearing?

    <p>To distribute the lubricant evenly ahead of the pressure area</p> Signup and view all the answers

    What is the primary advantage of using a continuous oil supply in a bearing?

    <p>It ensures a consistent and reliable supply of lubricant</p> Signup and view all the answers

    What is the result of having sharp corners at the joints of a bearing?

    <p>It tends to scrape the oil from the shaft</p> Signup and view all the answers

    What is the primary characteristic of the pumping action of the rotating shaft in a bearing?

    <p>It separates the shaft from the bearing surface</p> Signup and view all the answers

    What is the primary purpose of the bearing clearance space in a shaft bearing?

    <p>To facilitate the flow of lubricant to the pressure area</p> Signup and view all the answers

    What is the primary cause of wear in a bearing?

    <p>Stopping and starting periods</p> Signup and view all the answers

    What is the primary function of tilting pad bearings in industrial steam turbines?

    <p>To prevent metal-to-metal contact and establish oil wedges</p> Signup and view all the answers

    Why are axial thrust bearings designed to handle forces parallel to the axis of the shaft?

    <p>To prevent the shaft from moving in an axial direction</p> Signup and view all the answers

    What is the main characteristic of radial forces acting on bearings?

    <p>They are forces perpendicular to the axis of the shaft</p> Signup and view all the answers

    What is the purpose of the separator in antifriction bearings?

    <p>To prevent the rolling elements from coming into contact with each other</p> Signup and view all the answers

    What type of bearing is designed to handle radial loads?

    <p>Radial bearings</p> Signup and view all the answers

    What is the main purpose of chamfering or rounding off sharp edges in bearings?

    <p>To prevent scraping of the lubricant from the shaft</p> Signup and view all the answers

    What is the primary cause of radial forces on bearings?

    <p>The weight of the shaft</p> Signup and view all the answers

    What is the result of sliding friction in antifriction bearings?

    <p>The friction force is decreased</p> Signup and view all the answers

    What is the purpose of locating the lubricant application point in a portion of the bearing not under pressure?

    <p>To improve lubricant distribution</p> Signup and view all the answers

    What is the primary advantage of antifriction bearings over other types of bearings?

    <p>They reduce friction force</p> Signup and view all the answers

    What is the term used to describe forces perpendicular to the axis of the shaft?

    <p>Radial forces</p> Signup and view all the answers

    What is the consequence of water being applied directly to a hot bearing?

    <p>The bearing cap may shrink or distort, reducing the running clearance</p> Signup and view all the answers

    What is the primary function of the collar thrust bearing?

    <p>To prevent the shaft from moving in an axial direction</p> Signup and view all the answers

    What is the purpose of an auxiliary groove in a bearing?

    <p>To improve lubricant distribution</p> Signup and view all the answers

    What is the primary cause of shaft seizure in a bearing?

    <p>Reduced clearance due to bearing cap distortion</p> Signup and view all the answers

    What is the characteristic of the bearing material in collar thrust bearings?

    <p>It is cast-in in the locations where the thrust collars intersect</p> Signup and view all the answers

    What is the purpose of monitoring the temperature of large bearings in critical machinery?

    <p>To detect potential bearing failures and take corrective action</p> Signup and view all the answers

    What is the primary advantage of using water-cooled bearings?

    <p>Reduced operating temperature</p> Signup and view all the answers

    What is the consequence of improper bearing design?

    <p>Premature bearing failure</p> Signup and view all the answers

    What is the primary factor in determining the location of the lubricant application point in a bearing?

    <p>The pressure area in the bearing</p> Signup and view all the answers

    What is the primary purpose of lubrication in antifriction bearings?

    <p>To reduce the small amount of sliding friction present in the bearings</p> Signup and view all the answers

    What is the consequence of overfilling a bearing with grease?

    <p>The bearing will overheat and the lubricant will leak away</p> Signup and view all the answers

    Why is grease preferred in applications where speeds are moderate and temperatures are not extreme?

    <p>Because it is less likely to be flung out or leak from the bearings</p> Signup and view all the answers

    What is the purpose of the seals in an antifriction bearing?

    <p>To prevent foreign matter from entering the bearing housing</p> Signup and view all the answers

    What is the primary factor that determines the type of lubrication used in a bearing?

    <p>Operating conditions</p> Signup and view all the answers

    What is the result of mixing different types of grease in an antifriction bearing?

    <p>Unpredictable bearing performance and potential failure</p> Signup and view all the answers

    What is the primary purpose of lubrication in plain or shell bearings?

    <p>To separate the surfaces by means of a lubricating film</p> Signup and view all the answers

    Why is oil preferred in high-speed applications?

    <p>Because it produces less heat due to churning or displacing</p> Signup and view all the answers

    What is the benefit of using a continuous oil supply in a bearing?

    <p>It reduces the risk of overheating</p> Signup and view all the answers

    What is the purpose of the bearing seals in preventing corrosion?

    <p>To prevent corrosion of the bearing components</p> Signup and view all the answers

    What is the primary reason why a lubricant should not form a hard mass within the bearing?

    <p>It will prevent the rollers or balls from moving freely and cause wear</p> Signup and view all the answers

    What is the term for the indentations that can occur in the race surfaces of a stationary bearing due to vibration?

    <p>False Brinelling</p> Signup and view all the answers

    What is the maximum operating temperature that antifriction bearings can generally withstand?

    <p>120°C</p> Signup and view all the answers

    What is the consequence of improper fitting of a bearing onto a shaft?

    <p>It will cause cracking or splitting of the bearing race</p> Signup and view all the answers

    What is the purpose of removing the end covers when cleaning an oil-lubricated bearing?

    <p>To flush out old lubricant and sludge</p> Signup and view all the answers

    What is the recommended maximum amount of grease to add to an antifriction bearing after cleaning?

    <p>One-third full</p> Signup and view all the answers

    What is the result of not allowing excess grease to be expelled through the open drain plug after adding new grease?

    <p>The bearing will become over-pressurized</p> Signup and view all the answers

    What is the primary cause of premature bearing failure due to misalignment?

    <p>Uneven loading of the bearing</p> Signup and view all the answers

    Why is it important to warm up equipment before adding grease?

    <p>To distribute the grease throughout the bearing</p> Signup and view all the answers

    What is the purpose of using a single point automatic lubricator?

    <p>To ensure the correct amount of lubricant is applied at the correct time</p> Signup and view all the answers

    What is the consequence of not cleaning the bearing properly before re-lubricating?

    <p>The bearing will be damaged by contaminants</p> Signup and view all the answers

    What is the purpose of squirting some grease from the end of the gun to clear it of debris?

    <p>To prevent contaminants from entering the bearing</p> Signup and view all the answers

    What is the result of not allowing the machine to run after adding new grease?

    <p>The excess grease will not be expelled</p> Signup and view all the answers

    What is the purpose of using a multi-point automatic lubricator?

    <p>To lubricate multiple bearings at once</p> Signup and view all the answers

    What is the consequence of using a grease gun that is not properly cleaned and maintained?

    <p>The bearing will be damaged by contaminants</p> Signup and view all the answers

    What is the purpose of using a web-based calculator to determine the re-greasing interval?

    <p>To ensure the correct amount of grease is applied at the correct time</p> Signup and view all the answers

    What is the primary purpose of soaking the bearing in a clean solvent after it has been removed from the shaft?

    <p>To remove any remaining lubricant from the bearing</p> Signup and view all the answers

    What should be done to the bearing after it has been heated to the ideal temperature for installation?

    <p>It should be quickly slid onto the shaft and seated firmly</p> Signup and view all the answers

    What is the purpose of using a bearing puller to remove the bearing from the shaft?

    <p>To prevent damage to the bearing during removal</p> Signup and view all the answers

    What is the result of not properly cleaning the shaft or housing before installing a bearing?

    <p>The bearing may score or scratch the shaft or housing</p> Signup and view all the answers

    What should be done to the bearing after it has been cleaned and inspected?

    <p>It should be dipped in a rust preventer and wrapped in greaseproof paper</p> Signup and view all the answers

    What is the purpose of using clean heat-resistant gloves when handling bearings during installation?

    <p>To prevent contamination of the bearing</p> Signup and view all the answers

    What is the ideal temperature range for expanding a bearing to be installed on a shaft?

    <p>Between 80°C and 100°C</p> Signup and view all the answers

    What is the purpose of rotating the bearing by hand while submerged in a solvent?

    <p>To remove any remaining lubricant from the bearing</p> Signup and view all the answers

    What should be done to the bearing if it is found to be in satisfactory condition after inspection?

    <p>It should be dipped in a rust preventer and wrapped in greaseproof paper</p> Signup and view all the answers

    What is the result of uneven force application when removing a bearing from a shaft?

    <p>The bearing may be damaged during removal</p> Signup and view all the answers

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