USPS 955 Exam Answered
Which one of the following CANNOT be used as self-lubricating bushings? - Answer-
Sleeved bushings consist of metal, plastic, or reinforced fibers composites sleeves that
reduce noise and vibrations by reducing the friction between moving mechanical parts.
Oil (lubricants) foaming in gear mechanism is caused by: - Answer- Contamination of
lubricants with water
Which are the three main factors to consider when choosing a lubricant? - Answer-
Temperature, workload, speed of moving parts
The benefit/benefits of dynamic balancing are: - Answer- Low vibrations, low noise, and
higher bearing life
____________ roller bearings are available in cylindrical, barrel and taper shaped
rollers. - Answer- staggered
When pressing a bearing into the housing, you should press against _________. -
Answer- the outer race only
The purpose of a cylindrical roller bearing is to _________. - Answer- Contain redial
motion of the shaft
The three basic shapes of roller bearings are: - Answer- cylindrical, barrel, and tapered
The purpose of a thrust bearing is to: - Answer- Contain axial motion of the shaft
_____________ cause overheating in the bearing and reduces the bearing life. -
Answer- insufficient lubrication and speed
In order to remove a bearing from a steel shaft, ___________ can be used without
damaging the bearing or the shaft. - Answer- Dry ice and liquid nitrogen
____________ load is acting on the plane of the bearings' axis of rotation. - Answer-
Axial
Which of the following statements is true? - Answer- Zero-film are sliding bearing which
are lubrication-free
The characteristic number of the bearing is given by:
Z=absolute viscosity of the lubricant, N= speed of journal, p=bearing pressure - Answer-
ZN/p
, Also called eccentrically loaded bearing is: - Answer- Offset bearing
Reducing noise from sprockets and chain can be done by: - Answer- Choosing
sprockets with more teeth, using a lighter chain, lubricating the bottom of the sprocket
tooth
What is the advantage of bushing? - Answer- Self-lubricating, less noise, less vibration
Which of the following lubrication system is used in two stroke engines? - Answer- Mist
system
Thrust ball bearing are used to __________. - Answer- Counteract axial force
Which one of the following CANNOT be used as self-lubricating bushings? - Answer-
Sleeved bushings consist of metal, plastic, or reinforced fibers composites sleeves that
reduce noise and vibrations by reducing the friction between moving mechanical parts.
The throwout bearing and the spring diaphragm in a clutch are connected: - Answer-
When the clutch pedal is pressed
Bearing failure in motors can be caused due to wrong selection of bearings. A motor
mounted horizontally or vertically needs _____________ types of bearings. - Answer-
different
For a journal bearing design, the clearance ratio ("clearance") should be approximately
considered as: - Answer- 0.0010
Select a bearing to sustain axial as well as radial loads: - Answer- Tapered roller
bearing
Which of the following can provide bi-directional thrust load? - Answer- Thrust ball
bearings
Hydrostatic bearing usually use __________ as lubricant. - Answer- Oil
Oil whirl in journal bearing can be prevented by ________ - Answer- Providing an
obstacle to the whirling fluid or providing the stabilized loading are used to avoid whirls
Which of the following wear type occurs the least in a bearing when used in a turbine? -
Answer- Corrosion
V-belts are superior to flat belts because ________. - Answer- The belt does not slip
away and slip off from the pulley
Which one of the following CANNOT be used as self-lubricating bushings? - Answer-
Sleeved bushings consist of metal, plastic, or reinforced fibers composites sleeves that
reduce noise and vibrations by reducing the friction between moving mechanical parts.
Oil (lubricants) foaming in gear mechanism is caused by: - Answer- Contamination of
lubricants with water
Which are the three main factors to consider when choosing a lubricant? - Answer-
Temperature, workload, speed of moving parts
The benefit/benefits of dynamic balancing are: - Answer- Low vibrations, low noise, and
higher bearing life
____________ roller bearings are available in cylindrical, barrel and taper shaped
rollers. - Answer- staggered
When pressing a bearing into the housing, you should press against _________. -
Answer- the outer race only
The purpose of a cylindrical roller bearing is to _________. - Answer- Contain redial
motion of the shaft
The three basic shapes of roller bearings are: - Answer- cylindrical, barrel, and tapered
The purpose of a thrust bearing is to: - Answer- Contain axial motion of the shaft
_____________ cause overheating in the bearing and reduces the bearing life. -
Answer- insufficient lubrication and speed
In order to remove a bearing from a steel shaft, ___________ can be used without
damaging the bearing or the shaft. - Answer- Dry ice and liquid nitrogen
____________ load is acting on the plane of the bearings' axis of rotation. - Answer-
Axial
Which of the following statements is true? - Answer- Zero-film are sliding bearing which
are lubrication-free
The characteristic number of the bearing is given by:
Z=absolute viscosity of the lubricant, N= speed of journal, p=bearing pressure - Answer-
ZN/p
, Also called eccentrically loaded bearing is: - Answer- Offset bearing
Reducing noise from sprockets and chain can be done by: - Answer- Choosing
sprockets with more teeth, using a lighter chain, lubricating the bottom of the sprocket
tooth
What is the advantage of bushing? - Answer- Self-lubricating, less noise, less vibration
Which of the following lubrication system is used in two stroke engines? - Answer- Mist
system
Thrust ball bearing are used to __________. - Answer- Counteract axial force
Which one of the following CANNOT be used as self-lubricating bushings? - Answer-
Sleeved bushings consist of metal, plastic, or reinforced fibers composites sleeves that
reduce noise and vibrations by reducing the friction between moving mechanical parts.
The throwout bearing and the spring diaphragm in a clutch are connected: - Answer-
When the clutch pedal is pressed
Bearing failure in motors can be caused due to wrong selection of bearings. A motor
mounted horizontally or vertically needs _____________ types of bearings. - Answer-
different
For a journal bearing design, the clearance ratio ("clearance") should be approximately
considered as: - Answer- 0.0010
Select a bearing to sustain axial as well as radial loads: - Answer- Tapered roller
bearing
Which of the following can provide bi-directional thrust load? - Answer- Thrust ball
bearings
Hydrostatic bearing usually use __________ as lubricant. - Answer- Oil
Oil whirl in journal bearing can be prevented by ________ - Answer- Providing an
obstacle to the whirling fluid or providing the stabilized loading are used to avoid whirls
Which of the following wear type occurs the least in a bearing when used in a turbine? -
Answer- Corrosion
V-belts are superior to flat belts because ________. - Answer- The belt does not slip
away and slip off from the pulley
