MLA 2 - Chapter 2
Which of the following is not considered a solid additive? (PTFE) Polytetrofluoroethylene (MoS2) Molybdenum Disulfide (ZDDP) Zinc Dialkyldithiophosphate Graphite
(ZDDP) Zinc Dialkyldithiophosphate
Plowing, cutting, gouging and broaching are synonyms of what kind of wear Abrasion Erosion Adhesion Corrosion
Abrasion
Cold welding and scuffing are characteristic of Fatigue Adhesion Abrasion Cavitation
Adhesion
Galling, scuffing, seizing and severe sliding are synonyms of what kind of wear? Erosion Adhesion Corrosion Abrasion
Adhesion
Which of the following are considered the two dominant wear modes for lubricated surfaces? Adhesive and abrasive Corrosion and Erosion Fatigue and corrosion All are dominant wear modes
All are dominant wear modes
A common type of wear mechanism found in industrial gearboxes is Adhesive wear Abrasive wear Surface fatigue All of the above
All of the above
What are the essential functions of the lubricant Reduce Friction and Wear Cool Surfaces Remove Contaminant and provide corrosion control All of the above
All of the above
What is a lubricant A semi-fluid substance introduced between two interacting surfaces to improve the smoothness of movement A fluid substance introduced between two interacting surfaces to improve the smoothness of movement A gaseous substance introduced between two interacting surfaces to improve the smoothness of movement All of the above
All of the above
What is the process called where the asperities are removed by the force of brand new surfaces interacting in the presence of a lubricant? Seating Wear-in Run-in All of the above
All of the above
Which factor is important in establishing a hydrodynamic film between two surfaces? Speed Load (Pressure) Viscosity All of the above
All of the above
Which factors will influence the effectiveness of the machine lubrication condition? Temperature, Load, Speed Viscosity Index, machine surface condition, type of surface interaction Material Hardness, surface finish, viscosity All of the above
All of the above
Which of the following can be used as a lubricant? Mineral oil Water Air/Gas All of the above
All of the above
Which of the following could occur when the sump temperature increases to much? Mixed and/or boundary film conditions Metal contact Degraded lubricant All of the above
All of the above
Which of the following influences the fluids viscosity under EHD operating conditions? Load Temperature Pressure - Viscosity Coefficient All of the above
All of the above
Which of the following is known to disrupt EHD film formation? Air Water Heat All of the above
All of the above
Which of the following might be a cause for lubricant sump temperature increase? Too much oil Too thick oil High speed All of the above
All of the above
Which of the following wear modes is controllable for lubricated surfaces with properly selected lubricants and properly planned lubrication replenishment and management? Abrasive, adhesive, erosive Brinneling, fatigue, corrosion Abrasive, fretting and fatigue All of the above
All of the above
A.G.M.A. stands for? American Gear Makers Association American Gear Manufacturers Association Associated Gear Machineists of America None of the above
American Gear Manufacturers Association
Typical machine dynamic clearances Are the same as the machining clearance Are larger than the machining clearances Are smaller than the machining clearances Are not measurable
Are smaller than the machining clearances
Microscopic projections on a surface resulting from the finishing process are known as? Defects Asperities Pitting Scalling
Asperities
Abrasive wear is the result of ______ contact. Rolling Sliding Both A & B None of the above
Both A & B
What are the 3 stages of lubricant film formation within a machine that is progressing from idle state to a dynamic operating state. Boundary Film, Mixed Film, Fluid Film Hydrostatic Film, Hydrodynamic Film, Elasto Hydrodynamic Film Hydrostatic Film, ElastoHydrostatic Film, Mixed Boundary film Solid Film, Semi-Solid Film, Fluid Film
Boundary Film, Mixed Film, Fluid Film
Tribology is the study of which 3 areas of knowledge? Chemical, mechanical, electrical Surface finish, adhesion, wear Friction, lubrication, wear Design, construction, maintenance
Friction, lubrication, wear
What are the three modes of lubricant film condition? Full film, partial film, low film Full film, mixed film, boundary Visible, Opaque, Invisible Dry Sliding, Dry Rolling, Fluid
Full film, mixed film, boundary
Complete the sentence: As long as the EHD film is intact, and there is no surface contact, then the component is in a ____ ____ ____ condition. Full fluid film Full boundary film Mixed boundary film Efficient hydrodynamic film
Full fluid film
Which of the following desirable properties is missing from water based lubricants (glycols, emulsions, invert emulsions)? High PV coefficient Low VI Stable DMV Free VPN
High PV coefficient
Which film type is associated with sliding component interaction? MGM Hydrodynamic Elastohydrodynamic Hyperbolic
Hydrodynamic
Which of the following is not a purpose for a lubricant? Prevent surface contact Protect contact surfaces Improve contact surfaces Reduce friction
Improve contact surfaces
In an elasto-hydrodynamic oil film (EHL), the protective film Forms from an oil wedge that separates surfaces Is created by the plastic deformation of surfaces in rolling contacts Deposits a solid layer of wear resistant material during operation Forms an oil pressure wedge that separates surfaces
Is created by the plastic deformation of surfaces in rolling contacts
Surface fatigue and overload may cause _________ Machine failure Large wear particles Oil leaks None of the above
Large wear particles
An 'asperity' is considered A non-recurring event A unit of measure The ratio of the pounds of 'pull' force required to move the given pounds of static weight None of the above
None of the above
Which of the following defines a micron? One one-hundred thousandths of a meter One millionth of a meter One thousandths of a meter 1 ten thousandths of an inch
One millionth of a meter
A possible cause of surface fatigue is Overloading Misalignment Loss of EP/AW additives Low viscosity
Overloading
What is the primary function of a lubricant? Reduce Friction and Wear Increase machine life Transfer power Transfer heat
Reduce Friction and Wear
Tribological wear is the result of? Relative motion Contamination High pressure None of the above
Relative motion
What is the best definition of Friction? Resistance to movement between rolling contacts Improper machining of machine surfaces Inertia Resistance to movement between any two surfaces in relative motion
Resistance to movement between any two surfaces in relative motion
What is Friction? Energy produced by surfaces in relative motion Resistance to movement between two surfaces in relative motion Resistance between two surfaces under load and high rate of movement Resistance between the surfaces of layers of molecules in a tribosystem
Resistance to movement between two surfaces in relative motion
EHL conditions occur primarily in Rolling bearings, gears and cams Slow moving pins and bushings Piston rings and liners Journal bearings
Rolling bearings, gears and cams
Surface fatigue is caused by? Rolling contact Speed Lubrication None of the above
Rolling contact
Which would have the highest coefficient of friction Sliding dry friction Fluid friction Rolling friction Rolling Dry Friction
Sliding dry friction
All machine component movement can be described as which of the following? Surface friction Surface contact Fluid Friction Sliding or rolling contact
Sliding or rolling contact
What machine operational characteristic differentiates HD from EHD? Static versus dynamic operation Highly loaded versus lightly loaded surfaces Sliding versus rolling surface interaction Solid film versus full fluid film
Sliding versus rolling surface interaction
Which is not considered a 'fluid' or viscosity dependent protective film? Elasto-hydrodynamic Solid Suspension Film Hydrodynamic All are viscosity dependent
Solid Suspension Film
If the oil was to approach a solid state under pressure, which of the following would be true? The PV Coefficient would be low The PV Coefficient would be high The PV Coefficient would be non-existent VI Improvers have sheared and no longer functioning
The PV Coefficient would be high
What is hydrostatic lubrication? Lubrication using water Lubrication used at a hydroelectric generating plant The film created by one surface rapidly moving across another surface The fluid film generated from an externally applied pressure
The fluid film generated from an externally applied pressure
Asperities are formed by The machining of metal surfaces Surface interactions in a dry sliding state Surface interactions in dry rolling state Continuous, minute, high intensity oscillations in a dry contact
The machining of metal surfaces
What is Tribology The study of lubricant performance during dynamic operation The scientific study of machine surfaces in relative motion, including aspects of friction, wear and lubrication The scientific study of machine surfaces and their failure modes The scientific practice of machine lubrication activities designed expressly to achieve perfect machine surface separation and protection from friction, wear and degradation.
The scientific study of machine surfaces in relative motion, including aspects of friction, wear and lubrication
When oil is squeezed hard enough it can become apparently and momentarily solid. True False Neither True nor False Not enough information to decide
True
Abrasive wear subcategories include Two and three body wear Electrical and corrosive modes Cavitation and Erosion Fatigue and delamination
Two and three body wear
With which lubrication state would one associate classical cyclic fatigue wear HD EHD Boundary Mixed
EHD
Frictional resistance (Coefficient of Friction) is measured and characterized as A ratio of the force required to move a given amount of weight A ratio of energy required to sustain momentum for a given weight A ratio of weight required to prevent movement Internal resistance to flow.
A ratio of the force required to move a given amount of weight
What is a tribo-system A set of lubricated components that operate in proximity to one another and share a common lubricant sump A set of lubricated components that operate in proximity to one another without a lubricant sump. An exhaust gas-driven compressor used to increase the power output of an internal-combustion engine A set of three interacting components
A set of lubricated components that operate in proximity to one another and share a common lubricant sump
According to E. Rabinowicz, MIT, to what extent are combined abrasive and adhesive wear responsible for machine degradation? 15 Percent 25 percent 45 percent 75 Percent
45 percent
What is an asperity? A surface deformity, characterized by RMS (Root Mean Square) value beyond 3 sigma The difference between two points of measurement A surface irregularity found at any machine surface The degree of irregularity that can be measured at any machined surface
A surface irregularity found at any machine surface
High pressure air bubble collapse is a characteristic of Cavitation Adhesion Abrasion Fatigue
Cavitation
Which wear mode would be best characterized by Adhesive, Abrasive, and Erosive types of wear? Rolling friction Surface fatigue EHD Contact
Contact
Which statement is accurate Hydrodynamic films are created through momentary deformation of contact surfaces under load which establishes a 'flat spot' for the formation of an oil cushion. Elasto-hydrodynamic films are created through momentary deformation of contact surfaces under load, which establishes a 'flat spot' for the formation of an oil cushion. Elasto-hydrodynamic films are created through the forcing of a volume on oil into the contact area at a rate higher than the rate with which the oil can escape. Hydrodynamic films can be formed and sustained much more effectively as speeds approach <5 RPM
Elasto-hydrodynamic films are created through momentary deformation of contact surfaces under load, which establishes a 'flat spot' for the formation of an oil cushion
Cavitation is caused by? Sliding contact Water contamination Formation of an air or vapor pocket All of the above
Formation of an air or vapor pocket
In a hydrodynamic oil film, the lubricant Forms an oil pressure wedge that separates surfaces Only exists when the components are in contact Exists primarily in Rolling contacts Forms an oil pad in the contact zone of the plastically deformed components interface
Forms an oil pressure wedge that separates surfaces
Wear can best be described as: a)cumulative process where material is removed by millions of surface interactions through a combination of interaction modes b)catastrophic process caused by poor lubricant adhesive properties. c)process of surface degradation that occurs catastrophically, causing plowing, gouging, and scoring of surfaces d)product of asperity contacts in a hydrodynamic interface
a)cumulative process where material is removed by millions of surface interactions through a combination of interaction modes
"The science of reducing friction through the application of a suitable material between the rubbing surfaces of bodies in relative motion" is a definition of a)Tribology b)Lubrication c)Friction d)Wear
b)Lubrication
