Unit 1 Lubrication and bearings Flashcards
The point at which oil will give off enough vapour to ignite and burn continuously is known as the \_\_\_\_\_ point. Select one: a. Flash b. Ignition c. Fire d. Vaporization
C. Fire
Using pressurized air to blow out a cleaned bearing:
Select one:
a. Should only be done in well-ventilated areas
b. Must be done only while the bearing is hot
c. Will cause the bearing to become “pitted”
d. should be done at an angle so the bearing can spin
c. Will cause the bearing to become “pitted”
When grease is used in an antifriction bearing after cleaning, the bearing housing should not be filled \_\_\_\_\_ full. Select one: a. more than 1/3 b. more than 1/2 c. more than 3/4 d. less than completely
a. more than 1/3
A collar thrust bearing: Select one: a. Can support more load than a Michell thrust bearing b. Is an anti-friction type bearing c. Is used with steam turbines only d. Has boundary lubrication
d. Has boundary lubrication
The lubricant for an anti-friction bearing:
Select one:
a. Will separate the moving parts completely
b. Must be cooled
c. Could be a semi-solid lubricant
d. Should have a high viscosity
c. Could be a semi-solid lubricant
Large journal or sleeve bearings have grooves:
Select one:
a. In the high pressure area of the bearing babbit
b. Cut into the bearing housing
c. For distributing lubricant evenly just after the pressure area
d. In the non-pressure area
d. In the non-pressure area
A thrust bearing which does not utilize the oil wedge principle of lubrication is the: Select one: a. Michell type b. Collar type c. Radial type d. Kingsbury type
b. Collar type
When inspecting a dismantled bearing, the first indication of a failing bearing is: Select one: a. Cracked balls b. Roughness c. Discoloration d. Rusting or corrosion e. Tapered rollers
b. Roughness
The proper way to store a bearing after cleaning is to dip it in \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ and wrap it in grease-proof paper. Select one: a. a desiccant such as rice b. Wax c. Solvent d. A rust preventative
d. A rust preventative
The instrument that measures the viscosity of an oil at a certain temperature as it flows through a small diameter tube, is called: Select one: a. An orifice plate b. A Saybolt viscometer c. An oil meter d. A vena contracta
b. A Saybolt viscometer
The property of oil that indicates its ability to support a load is: Select one: a. Viscosity b. Viscosity index c. Pour point d. Floc point
a. Viscosity
A normal anti-friction bearing temperature operating range is: Select one: a. 150°C to 160°C b. 20°C to 50°C c. 65°C to 70°C d. 80°C to 120°C
c. 65°C to 70°C
A large journal bearing which is running hotter than normal can be cooled by:
Select one:
a. Direct application of cool water
b. Loosening the bearing caps
c. Decreasing the viscosity of the oil by cooling it
d. pumping additional grease into it
b. Loosening the bearing caps
With antifriction bearings using grease, the bearings:
Select one:
a. Must be cleaned twice as often as oil-lubricated bearings
b. can be cleaned by adding solvent to the grease cartridge
c. Are cleaned less often than oil-lubricated bearings
d. Never require cleaning
c. Are cleaned less often than oil-lubricated bearings
The oil for a refrigeration compressor must: Select one: a. Have a low pour point b. Have a high flash point c. Have a high fire point d. Be a multi-grade type
a. Have a low pour point
A material that is commonly used as a solid lubricant is: Select one: a. Tallow b. Lime c. Molybdenum disulfide d. Sodium carbonate
c. Molybdenum disulfide
The ability of an oil to lift and support heavy loads depends upon: Select one: a. kinetic energy b. Hydraulic pressure c. acceleration d. Pour point
b. Hydraulic pressure
Grease:
Select one:
a. Is a semi-liquid
b. Is an excellent high-speed, low load lubricant
c. Attracts dirt and water to bearings, leading to premature failure
d. Can be used under conditions where oil may leak away and leave the bearing dry
d. Can be used under conditions where oil may leak away and leave the bearing dry
A type of anti-friction bearing is the \_\_\_\_\_ . Select one: a. Kingsbury b. Ball bearing c. Sleeve bearing d. Journal bearing
b. Ball bearing
A common cause of antifriction bearing failure is: Select one: a. High RPM service b. Extreme cold temperature cracking c. Drive motor overload d. Shaft misalignment
d. Shaft misalignment
Which type of oil produces higher fluid friction? Select one: a. High viscosity oil b. Low viscosity oil c. Synthetic oils d. Fixed oils
a. High viscosity oil
The characteristics of a grease are determined by: Select one: a. Its thickening agent or “soap” b. Its consistency c. The type of oil used in the grease d. Its protective coating
a. Its thickening agent or “soap”
All semi-solid lubricants: Select one: a. Have a low viscosity b. Are capable of sealing out dirt and water from bearings c. Contain graphite d. Resist moisture
b. Are capable of sealing out dirt and water from bearings
If ambient air temperatures are very low, the preferred lubricant is a: Select one: a. Solid b. Semi-solid c. Fixed oil d. Liquid
a. Solid
A shell type bearing: Select one: a. Is used for axial thrust b. Is an anti-friction bearing c. Consists of ball bearings in a shell d. Is used for heavy loads
d. Is used for heavy loads
If an oil’s viscosity changes a lot with very little temperature change, it will have a: Select one: a. Low viscosity index b. High pour point c. High viscosity index d. Low pour point
a. Low viscosity index
A journal(Shaft) bearing: Select one: a. Controls thrust movement b. Does not require lubrication c. require cooling water d. Supports a shaft
d. Supports a shaft
Air compressor oil should: Select one: a. Have a very low viscosity b. Have low carbon residue c. Have a low flash point d. Not contain anti-oxidants
b. Have low carbon residue
Where gear teeth inter-mesh, a lubricant must provide Select one: a. Corrosion prevention b. Sealing c. Shock absorption d. Temperature control
c. Shock absorption
When replacing or removing an anti-friction ball bearing, the applied force should:
Select one:
a. Not be transmitted through the bearing balls
b. Always be against the inner race
c. Always be against the outer race
d. Be made only after heating the bearing
a. Not be transmitted through the bearing balls
The majority of lubricants are: Select one: a. Animal fats b. Synthetic oils c. Mineral oils d. Greases
c. Mineral oils
The resistance of a liquid to internal deformation or shear is known as: Select one: a. Pour point b. Viscosity index c. Flash point d. Viscosity
d. Viscosity