3 - 4 Flashcards
The revolving runner of a hydraulic turbine is said to have:
A) rectilinear plane motion
B) curvilinear plane motion
C) rotating plane motion
D) a combination of all three motions
C) rotating plane motion
pg 3
The balls of the fly ball governor, when the speed of rotation is increasing or decreasing, is said to have:
A) Helical motion
B) Spherical motion
C) Intermittent motion
D) Plane motion
B) Spherical motion
pg 3
Critical speed is defined as:
A) Any speed above designed operating speed
B) Any speed below designed operating speed
C) That speed for which protective devices are set to trip
D) A speed that creates a centrifugal force greater than the elastic resolving force of the shaft
D) A speed that creates a centrifugal force greater than the elastic resolving force of the shaft
pg 5
All of the below statements concerning critical speed are true except:
A) Critical speed is determined by the weight and dimensions of a shaft
B) Machines designed to operate below the critical speed are said to have rigid shafts
C) Most all hydraulic turbine units have rigid shafts
D) Each shaft will have only one critical speed
D) Each shaft will have only one critical speed
pg 5 & 7
A mechanism that produces the snapping action when circuit breakers are opened or closed uses the principle of the:
A) Toggle
B) Bell crank
C) Pitman
D) Ratchet
A) Toggle
pg 9
Which one of the below statements concerning belts and pulleys are not true?
A) ‘V’ belts should be fitted to ride more towards the top and less towards the bottom of the pulley
B) Protective guards should generally be installed around moving belts
C) the purpose of the idler is to reverse the direction of rotation of a belt drive
D) Flat belt pulleys care “crowned” to help keep flat belts running in the center of the pulley
C) the purpose of the idler is to reverse the direction of rotation of a belt drive
*Function of an idler is to increase the arc of contact of the belt. To serve as a take-up device, and in some cases to guide a belt in an angle drive
pg 15
Select one of the below statements concerning gears that is false?
A) spur gears transmit motion between parallel shafts
B) Helical gear teeth create an end trust
C) Herringbone gears cause end trust on shafts
D) Bevel gears transmit rotary motion around a corner
C) Herringbone gears cause end thrust on shafts
*correct statement is: Herringbone gears does not cause end thrust on the shafts
pg 23
Most flexible couplings:
A) Are designed to compensate for large amounts of shaft misalignment
B) Are designed to fail under high torque loads
C) Require some form of lubrication to reduce friction
D) use rubber bushings to absorb shaft misalignment
C) Require some form of lubrication to reduce friction
pg 29 & 34
Hydraulic couplings are generally used with:
A) Variable speed units
B) Constant speed units
C) High speed units
D) Slow speed units
A) Variable speed units
pg 34
Magnetic drives can be used as a:
A) Clutch
B) Slip Coupling
C) Reversible Drive
D) All Three
D) All three
pg 39
