An
improvised flexible coupling made of car tire pieces connects the drive
shafts of an engine and a water pump. This one is used to cancel out
misalignment and vibrations.
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power.
Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded.
A rigid coupling may also be added between shafts to reduce shock and wear at the point where the shafts meet.
When joining shafts within a machine, mechanics can choose between flexible and rigid couplings.
While flexible units offer some movement and give between the shafts, rigid couplings are the most effective choice for precise alignment and secure hold.
They generally are large enough so that screws can pass all the way through the coupling and into the second half to ensure a secure hold.Flanged rigid couplings are designed for heavy loads or industrial equipment.
Rigid couplings are used when precise shaft alignment is required; shaft misalignment will affect the coupling's performance as well as its life.
A clamp coupling is different
from the sleeve coupling in that the sleeve used in this type is split
from one side.The shafts are entered and keyed to this sleeve and then
split sides are screwed together.
A beam coupling, also known as helical coupling, is a flexible coupling for transmitting torque between two shafts while allowing for angular misalignment, parallel offset and even axial motion, of one shaft relative to the other. This design utilizes a single piece of material and becomes flexible by removal of material along a spiral path resulting in a curved flexible beam of helical shape.
Since it is made from a single piece of material, the Beam Style coupling does not exhibit the backlash found in some multi-piece couplings.
Gear couplings are generally limited to angular misalignments, i.e., the angle of the spindle relative to the axes of the connected shafts, of 4-5°.
Single joint gear couplings are also used to connected two nominally coaxial shafts.
Requirements of good shaft alignment / good
coupling setup it should be easy to connect or disconnect the coupling.
it does allow some misalignment between the two adjacent shaft rotation
axes. it is the goal to minimise the remaining misalignment in running
operation to maximise power transmission and to maximise machine runtime
. it should have no projecting parts. it is recommended to use
manufacturer's alignment target values to set up the machine train to a
defined non-zero alignment, due to the fact that later when the machine
is at operation temperature the alignment condition is perfect
Coupling maintenance is generally a simple matter, requiring a regularly scheduled inspection of each coupling.
Checking and changing lubricant regularly if the coupling is lubricated. This maintenance is required annually for most couplings and more frequently for couplings in adverse environments or in demanding operating conditions.
The only way to improve coupling life is to understand what caused the failure and to correct it prior to installing a new coupling.
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power.
Couplings do not normally allow disconnection of shafts during operation, however there are torque limiting couplings which can slip or disconnect when some torque limit is exceeded.
Types
Rigid
A rigid coupling is a unit of hardware used to join two shafts within a motor or mechanical system.A rigid coupling may also be added between shafts to reduce shock and wear at the point where the shafts meet.
When joining shafts within a machine, mechanics can choose between flexible and rigid couplings.
While flexible units offer some movement and give between the shafts, rigid couplings are the most effective choice for precise alignment and secure hold.
They generally are large enough so that screws can pass all the way through the coupling and into the second half to ensure a secure hold.Flanged rigid couplings are designed for heavy loads or industrial equipment.
Rigid couplings are used when precise shaft alignment is required; shaft misalignment will affect the coupling's performance as well as its life.
Flexible
Flexible couplings are used to transmit torque from one shaft to another when the two shafts are slightly misaligned.A beam coupling, also known as helical coupling, is a flexible coupling for transmitting torque between two shafts while allowing for angular misalignment, parallel offset and even axial motion, of one shaft relative to the other. This design utilizes a single piece of material and becomes flexible by removal of material along a spiral path resulting in a curved flexible beam of helical shape.
Since it is made from a single piece of material, the Beam Style coupling does not exhibit the backlash found in some multi-piece couplings.
Gear
A gear coupling is a mechanical device for transmitting torque between two shafts that are not collinear .Gear couplings are generally limited to angular misalignments, i.e., the angle of the spindle relative to the axes of the connected shafts, of 4-5°.
Single joint gear couplings are also used to connected two nominally coaxial shafts.
Oldham
An Oldham coupling has three discs, one coupled to the input, one coupled to the output, and a middle disc that is joined to the first two by tongue and groove .Coupling maintenance is generally a simple matter, requiring a regularly scheduled inspection of each coupling.
Checking and changing lubricant regularly if the coupling is lubricated. This maintenance is required annually for most couplings and more frequently for couplings in adverse environments or in demanding operating conditions.
The only way to improve coupling life is to understand what caused the failure and to correct it prior to installing a new coupling.
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