Section 3 Flashcards
Keys are meant to be
The weak link
Another name for the Pratt and Whitney
 Buried key
What are woodruff key is good for
Light applications, small, pulleys, and gears
What are gib keys good for?
Heavy loads, they have an 1/8 of an inch taper per foot.
Can you use a jib head key with cast-iron?
No
Two helical gear is in mesh and rotating under torque produce thrust. Helical, spine, offset or counteracts that axle or ends rust.
U joint both ends of driveshaft must face both yokes in the same direction?
Yes, or they will develop tremendous vibration problems
Tapers and eccentrics are locking devices used to mount components to shafts 
Used for bearings sprockets and sheaves. 
Retainer rings or snaprings are used for
Provided with a removable shoulder to locate retain or lock component, on shaft, boars, and inside housing
What is torsional stress?
Torsional, shear stress is torquing twisting stress
Other than a solid round cross-section what other shafts could you get?
Square, hex and hollow
What is hollow shafting not good for?
Hollow shaft and is not good for shock load applications because it is less resilient than solid shafting
What is the purpose of line shafting?
To supply power to or timing several devices on a single shaft
What are the alloying elements
Aluminum carbon, chromium, copper, and lead.
What does a ANSI stand for.
American national standards institute.
What are the three basic groups of ANSI?
Number one RC running and sliding fits
Number 2LC, LT & LN locational fits
 Number 3FN force fits
What are couplings?
Power transmission components
What is the compression coupling good for?
Light to moderate loads, they can be two different diameters
What do you want to do with ribbed couplings after their installed?
Insure the gap between the two halves is equal
When is a rigid multi bore used?
Vertical pumps
How do you mount a flanged faced coupling?
Heavy interference, fit or taper fit, in some cases, the flange is forged part of the shaft.
Is a rigid coupling, low maintenance
Yes, and no lube needed
Is the equipment always rated for the same misalignment as the coupling?
No, and it can lead to premature seal and bearing failure
What is the absolute maximum?
Specified misalignment rating from the manufacture
What is the most common type of roller chain?
The double strand roller chain
What is the material flexible coupling
Constructed to allow parts of the coupling to flex, when it is subjected to misalignment, load changes and reversing and shock loads.
A single flexible metal disc coupling cannot tolerate angular misalignment.
No
What are the types of material and mechanical flexible coupling
Steel grid, Jaw and spider, splined rubber, pin and disc , pin, and rubber bushing coupling
Centrifugal, design, couplings what are the characteristics?
Soft start, smooth, acceleration, overload protection, dampening, shockload
Dry, shot fluid coupling what is the inner section of the coupling called?
The rotor
Centrifugal shoe coupling
It allows the prime mover to reach partial speed before the load is fully engaged, it is good on drives it frequently stop and start under heavy loads.
When do you use gears?
When slippage is not acceptable
What are open gears good for
They are suitable for light, duty drives, or in situations when sealing the gears from the elements is difficult or impossible
 What are gears?
Gears are the mechanical advantage
What kind of lubrication can be used in an enclosed gear
Either grease or oil
What is another name for a crown gear?
The ring gear
Which gear is the pinion?
 The gear with fewer teeth, and is usually the drive gear
How many bearings does an overhang have?
One
How efficient are chains
98 to 99% efficient
What is the recommended slack of chains.
2 to 3%
Using a spring clip on a chain, which end should face the direction of travel
The closed end
How much will an offset link shorten the length of a chain?
One pitch
How are heavy series chains designated?
H following the number
Loading factors, a three strand is how much stronger than a single
2.5 times.
A sintered bushing chain capacity
Is 10% less than a standard chain, but it’s five times the life
Classical standard series
A,B,C ,D or E
V belts are the most effective means of power transmission
Yes
What is the minimum arc of contact. V belt
120
Compression material
Transmits the power between the Sheave and the tensile member
What is the pitch line?
Runs through the load carrying zones of the belt where tension members are located
Cogged belts have
Greater flexibility
High capacity
3v, 5v 8v
Poly v belts
J, K, L
Round belt is for
1/4 turn drives
Surpentine drives
Open ended
Rounded belts are used for
Light duty
Can you use an idler on a reversing drive?
No
Double v belts
AA , BB and CC
Are chain drives is more efficient than V belt drives
Yes
Chain dimensions are proportional to chain pitch
Yes
What chain type is used to transfer maximum power with the smallest pitch size
Multiple strand
What v belt choice would best suit a serpentine Drive
A double V belt
What Veebelt could solve the problem of continually rolling over or jumping pully grooves
Banded
Can you use poly V belts in reverse, bend applications?
Yes
What type of chain-link Bends less should be used on small diameter sprockets
Short
Standard roller chain width is equal to
5/8 times pitch
A truncated cone would represent what type of gear
A bevel gear
The hand of the spiral on the spiral bevel gears is indicated by the direction in which the teeth curve
Away from the shafts axis
Mitre gears set is used
On shafts intersecting at right angles, on parallel shafts, and on 1 to 1 drives
Which gear system produces no axial thrust
Spiral bevel, double helical,
The direction of thrust produced by a helical gear
The direction of the helix angle, the direction of gear rotation
Which system do both input and output shaft rotate in the same direction
Internal spur gear
What is the gap on a QD bushing between sprocket and flange
1/8–1/4
