Couplings Flashcards
(23 cards)
What is a coupling and what are the two basic classes of industrial couplings
a coupling is a mechanical device used to connect two rotating shafts for the purpose of transmitting torque
RIGID
FLEXIBLE-allow for end float or end play
What is end float or endplay
The inclination of shafts to move back and forth across their bearings
List three common types of rigid couplings and provide a short explanation of each type
Sleeve coupling-
finished bore
tapered bushing
Ribbed coupling
flange couplingWhat is ribbed coupling
As coupling that is like a split sleeve. It is split by a parallel line and bolted together
What is a flange coupling
The opposite of the ribbed coupling. It is split vertically with bolts going parallel to shaft
Why must rigid couplings be perfectly aligned
Without perfect alignment there will be excessive bearing wear. Rigid couplings are joined as if they were welded
Which type of coupling is designed for heavy duty applications and high torque and speeds
flange couplings
What is the ultimate goal when selecting a coupling
long life and trouble free service
List the two categories of industrial couplings by their flexible members construction
Metallic couplings
Elastomeric couplings
Name the three most common type of metallic element couplings found in indusrty
CHAIN couplings-use a roller chain on the circumference to tighten. also come with silent tooth
GEAR couplings
GRID couplings- a continuous s shaped springs goes through grooves along the entire coupling
why do most chain couplings require lubrication
Because of the metal to metal contact of the moving parts
the exception is nylon chain couplings
Where are nylon chain coupling normally used
Light duty application
corrosive environments
industrializes where you do not want conataminants
THe elastomeric coupling insert is loaded in compression or shear. What is the difference
The insert is what fills the space. could look like a star or the spiders from work
Compression-pinned, bolted or molded to coupling hub (spider)
shear-usually bolted or clamped to hubs, can withstand more misalignment and provide better shock absorbing abilities
All elastomeric couplings work
better than other couplings in shock and vibration type industries
Name the two types of elastomeric couplings that are loaded in shear
Rubber tire-two flanged clamp the rubber tire in place, allowing it two flex as needed
Donut
What is the difference between a clearance and an interference fit when installing a coupling
Clarence fit- hub will slide onto shaft without forcing or heating
Interference fit-hub must be heated so it will expand
Name the two types of elastomeric couplings that are loaded in compression
Jaw type
Rubber bushing
What are the three basic methods for coupling alignment
Straightedge
Dial indicator
Laser
Test have shown that precision alignment can increase bearing life and seal life on average
6 years
What is runout
Amount of WOBBLE caused by loose machinery bearings or bent shaft or poorly machined parts
What is soft foot
condition that exists when foot of a machine does not equally support its weight
What are the two types of misalignment for
Angular misalignment
parallel misalignment
What is the most accurate method of coupling alignment
laser alignment
