coupling Flashcards
metal couplings
use a metal element that is designed to allow one or more types of shaft misalignment
grid coupling
uses a metal grid that is inserted into grooves in the two coupling halves
low cost, torsionally soft, allowing it to accept shock loads and dampen vibration
requires grease and must be used with a cover
chain coupling
use a double strand roller chain to connect to the two hubs
more torsionally soft than grid couplings
gear coupling
uses hubs with external gear teeth that are coupled together by an internally geared sleeve
available in much larger power sizes
torsionally rigid
split sleeve attaches the two hubs via a flange
requires grease lubrication
disc couplings
uses a stack of thin metal discs as a connecting element between the two coupling halves
torsionally very rigid
does not require lubrication
bellows coupling
uses a one-piece design that has formed metal accordion-like shape in its center
used for smaller power applications
does not require lubrication
what kind of chain can be used in a chain coupling
roller chain
silent chain
derlin chain
what must you use if grease is used with a chain coupling
a cover that wraps around the coupling
what are cahin couplings best suited for
applications that have medium to high power(10-900 hp)
what methods can you use to align chain couplings?
straight edge, with some modification
rim and face method
what does a gear coupling consist of?
two hubs with external gear teeth
a flange that connects the two hubs
what type of lubrication does gear coupling require
grease, with its sleeves acting as a cover to contain the grease
what are the five steps to determine coupling selection
determine DP
per-select applicable couplings
select one coupling size from each applicable type
determine the best coupling
list part numbers
what are the three steps of pm for couplings
check the lubrication
check the alignment(
set-screw and bushing cap-screw check
what is the pre-defined frequency for inspection?
100 hours of operation
periodically, once per year
what kind of holes do taper lock bushings have
semi-circular holes that match with semi-circular holes in the hub
what is the minor change in a variable-speed V-belt drive installation
the sheaves may or may not be matched
what is an idle pulley used for in a V-belt drive
add tension to the belt, keep long belts from whipping, or automatically adjust tension under varying loads
why is using idle pulleys to add tension not recommended
because it adds stress to the belt which will cause it to wear more quickly
inside idler
designed to add tension to the belt
tension is added by positioning the pulley so that it pushes out on the belt
backside idle
designed to add tension to the belt
does so by positioning the pulley so that it pushes in on the belt
helps increase the arc of contact
kiss idler
gently contacts the belt along its normal path so that any vibration or whipping of the belt is reduced
1st flexmetal coupling
gear
2nd flexmetal
chain
