SHAFT COUPLINGSBUYING GUIDE

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SHAFT COUPLINGS A ThomasNet Buying Guide

Shaft Couplings are mechanical devices used to connect

rotating shafts and absorb misalignments between them

Couplings can be rigid or flexible depending on the

alignment accuracies of the system and torque

requirements Shaft couplings are used for power and torque transmission between two rotating shafts

such as on motors and pumps compressors and generators

Coupling Styles

Beam The beam coupling consists of single or multiple helical cuts in the

coupling body which typically can accommodate parallel

misalignments up to 0025 inch and angular misalignments up to 7

degrees They are used primarily for motion control applications

where torques are typically below 100 inch-lbs Zero backlash

designs available ensure positioning accuracy between driving and

driven shafts

Bellows Bellows couplings are also suited to motion control applications They

consist of multiple convolutions of metal which provide high torsional

stiffness which is important to positioning applications Torsional stiffness

reduces the level of angular and parallel misalignment they can

accommodate compared with beam couplings although torque

transmission capabilities are about similar

Chain Chain couplings are suited to power transmission applications and are used

to transmit power up into the hundreds of horsepower range Angular and

parallel misalignment allowances are typically 2 degrees and 0015 inch

respectively Typical chain couplings use special chain sprockets and double

wide roller chains whose clearances permit the design to operate as a

flexible coupling

Jaw Curved and Straight Jaw couplings are used for both motion control and light power transmission

applications and consist of pairs of multi-jawed hubs that mate with elastomeric spiders The design

allows for backlash-free torque transmission Accommodation for

parallel misalignment usually approaches 001 inch and angular

misalignment about 1 degree Elastomeric spiders give these couplings

some damping capacity and of often the spiders are available in different

durometers to lend specific properties to the individual couplings These

couplings often operate without lubricant and can transmit torque up

into the 1000 inch-lb range

Diaphragm Diaphragm couplings are generally used for high power

transmission such as found in turbomachinery Typically

they employ one or more flexible metal convoluted discs

which transmit power to an inner spacer shaft then back

out through another diaphragm stack to the driven

machinery A principal advantage over gear type

couplings is their lack of lubrication requirements

Diaphragm couplings are capable of high torque

transmission and high speed operation

Disc Disc couplings use single or multiple discs and single or double

stages which bolt to the shaft hubs They are used for power

transmission and rely on the flexibility of their thin metal discs to

transmit torque and accommodate angular misalignment They are

not especially good at managing parallel misalignment They are capable of transmitting high torques

and are often used to couple high horsepower motors gas turbines etc to loads

Gear Gear couplings also transmit high torques They have misalignment

capabilities generally about 001-002 inch in parallel and 2 degrees in

angular Gear couplings are often used in pairs with spacer shafts to

span the distance between driving and driven equipment They

generally require lubricant although some designs intended for lighter

duty use lubricant free nylons or other polymers for the center sleeve

Grid Grid couplings employ spring like connecting elements that weave

between slots machined in the coupling hubs They are capable of high

torque transmission with an added bonus of shock absorption and

torsional vibration dampening They operate without lubricant They are

appropriate for power transmission and capable of handling parallel

misalignment up to 030 inch and angular misalignment of about frac14 degree

Oldham Oldham couplings handle high degrees of parallel

misalignment owing to their sliding element design Use of

an elastomer center element instead of metal is popular in

modern versions Some manufactures claim an ability to

tolerate up to 5 degree angular misalignment through the

use of cylindrical rather than rectangular sliders

Schmidt Schmidt couplings

are designed specifically to operate on shafts that are offset They

arenrsquot flexible couplings in the strictest sense which are designed

to accommodate slight misalignment in shafts that are

theoretically parallel and square to one another Schmidt couplings

are used in papermaking printing and similar machines and

function more like a 11 gearbox in

a more compact space

Clamping Rigid one- and two-piece Clamping couplings lack accommodation for

shaft misalignment and are popular for slow or intermittent shafting

arrangements where alignment is not of concern They are the simplest

form of shaft coupling and apart from their lack of misalignment

tolerance are inexpensive zero-backlash devices

Other couplings Coupling designs are many only the principal ones are detailed above Other coupling types include

meshing tooth or Hines designs pin and bush couplings and spline couplings

Applications and Industries Couplings correct for an inability to produce or maintain

perfect alignment in coupled machines Some machines

dispense with the need for couplings by running close

coupled meaning that the bearings of the motor support

an extended shaft upon which the rotating component of

the driven equipmentmdasha pump impeller for instance---

mounts The

motor and

pump at right is

an example of a

close-coupled

machine Where this is practical to do it is done to dispense

with he alignment problem Often though the machines

require their own bearings and as a result a need to connect

their independent shafts The diagram above shows the two

misalignments that can be expected parallel or offset (top)

and angular (bottom)

For some couplings backlash is an important concern Motion control applications where position of the

driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash

coupling to assure that no slop exists in the system Backlash is a lesser concern for most power

transmission applicationsmdashpumpsmotors for instancemdashwhere efficient torque transmission is the

primary objective Here misalignment can lead to higher energy use accelerated bearing wear

excessive vibration etc

Both the beam and the bellows couplings offer zero backlash and are frequently used for transferring

the relatively small torques of motion control

For power transmission generally all-metal couplings such as the gear and disc designs are capable of

transmitting higher torques than those that use elastomeric elements such as jaw couplings

Although couplings are designed to accommodate misalignment they arenrsquot substitutes for aligning

machines during installation

Considerations In selecting couplings a designer first needs to consider motion control varieties or power transmission

types Most motion control applications transmit comparatively low torques Power transmission

couplings in contrast are designed to carry moderate to high torques This decision will narrow

coupling choice somewhat Torque transmission along with maximum permissible parallel and angular

misalignment values are the dominant considerations Most couplings will publish these values and

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

SHAFT COUPLINGS A ThomasNet Buying Guide

Shaft Couplings are mechanical devices used to connect

rotating shafts and absorb misalignments between them

Couplings can be rigid or flexible depending on the

alignment accuracies of the system and torque

requirements Shaft couplings are used for power and torque transmission between two rotating shafts

such as on motors and pumps compressors and generators

Coupling Styles

Beam The beam coupling consists of single or multiple helical cuts in the

coupling body which typically can accommodate parallel

misalignments up to 0025 inch and angular misalignments up to 7

degrees They are used primarily for motion control applications

where torques are typically below 100 inch-lbs Zero backlash

designs available ensure positioning accuracy between driving and

driven shafts

Bellows Bellows couplings are also suited to motion control applications They

consist of multiple convolutions of metal which provide high torsional

stiffness which is important to positioning applications Torsional stiffness

reduces the level of angular and parallel misalignment they can

accommodate compared with beam couplings although torque

transmission capabilities are about similar

Chain Chain couplings are suited to power transmission applications and are used

to transmit power up into the hundreds of horsepower range Angular and

parallel misalignment allowances are typically 2 degrees and 0015 inch

respectively Typical chain couplings use special chain sprockets and double

wide roller chains whose clearances permit the design to operate as a

flexible coupling

Jaw Curved and Straight Jaw couplings are used for both motion control and light power transmission

applications and consist of pairs of multi-jawed hubs that mate with elastomeric spiders The design

allows for backlash-free torque transmission Accommodation for

parallel misalignment usually approaches 001 inch and angular

misalignment about 1 degree Elastomeric spiders give these couplings

some damping capacity and of often the spiders are available in different

durometers to lend specific properties to the individual couplings These

couplings often operate without lubricant and can transmit torque up

into the 1000 inch-lb range

Diaphragm Diaphragm couplings are generally used for high power

transmission such as found in turbomachinery Typically

they employ one or more flexible metal convoluted discs

which transmit power to an inner spacer shaft then back

out through another diaphragm stack to the driven

machinery A principal advantage over gear type

couplings is their lack of lubrication requirements

Diaphragm couplings are capable of high torque

transmission and high speed operation

Disc Disc couplings use single or multiple discs and single or double

stages which bolt to the shaft hubs They are used for power

transmission and rely on the flexibility of their thin metal discs to

transmit torque and accommodate angular misalignment They are

not especially good at managing parallel misalignment They are capable of transmitting high torques

and are often used to couple high horsepower motors gas turbines etc to loads

Gear Gear couplings also transmit high torques They have misalignment

capabilities generally about 001-002 inch in parallel and 2 degrees in

angular Gear couplings are often used in pairs with spacer shafts to

span the distance between driving and driven equipment They

generally require lubricant although some designs intended for lighter

duty use lubricant free nylons or other polymers for the center sleeve

Grid Grid couplings employ spring like connecting elements that weave

between slots machined in the coupling hubs They are capable of high

torque transmission with an added bonus of shock absorption and

torsional vibration dampening They operate without lubricant They are

appropriate for power transmission and capable of handling parallel

misalignment up to 030 inch and angular misalignment of about frac14 degree

Oldham Oldham couplings handle high degrees of parallel

misalignment owing to their sliding element design Use of

an elastomer center element instead of metal is popular in

modern versions Some manufactures claim an ability to

tolerate up to 5 degree angular misalignment through the

use of cylindrical rather than rectangular sliders

Schmidt Schmidt couplings

are designed specifically to operate on shafts that are offset They

arenrsquot flexible couplings in the strictest sense which are designed

to accommodate slight misalignment in shafts that are

theoretically parallel and square to one another Schmidt couplings

are used in papermaking printing and similar machines and

function more like a 11 gearbox in

a more compact space

Clamping Rigid one- and two-piece Clamping couplings lack accommodation for

shaft misalignment and are popular for slow or intermittent shafting

arrangements where alignment is not of concern They are the simplest

form of shaft coupling and apart from their lack of misalignment

tolerance are inexpensive zero-backlash devices

Other couplings Coupling designs are many only the principal ones are detailed above Other coupling types include

meshing tooth or Hines designs pin and bush couplings and spline couplings

Applications and Industries Couplings correct for an inability to produce or maintain

perfect alignment in coupled machines Some machines

dispense with the need for couplings by running close

coupled meaning that the bearings of the motor support

an extended shaft upon which the rotating component of

the driven equipmentmdasha pump impeller for instance---

mounts The

motor and

pump at right is

an example of a

close-coupled

machine Where this is practical to do it is done to dispense

with he alignment problem Often though the machines

require their own bearings and as a result a need to connect

their independent shafts The diagram above shows the two

misalignments that can be expected parallel or offset (top)

and angular (bottom)

For some couplings backlash is an important concern Motion control applications where position of the

driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash

coupling to assure that no slop exists in the system Backlash is a lesser concern for most power

transmission applicationsmdashpumpsmotors for instancemdashwhere efficient torque transmission is the

primary objective Here misalignment can lead to higher energy use accelerated bearing wear

excessive vibration etc

Both the beam and the bellows couplings offer zero backlash and are frequently used for transferring

the relatively small torques of motion control

For power transmission generally all-metal couplings such as the gear and disc designs are capable of

transmitting higher torques than those that use elastomeric elements such as jaw couplings

Although couplings are designed to accommodate misalignment they arenrsquot substitutes for aligning

machines during installation

Considerations In selecting couplings a designer first needs to consider motion control varieties or power transmission

types Most motion control applications transmit comparatively low torques Power transmission

couplings in contrast are designed to carry moderate to high torques This decision will narrow

coupling choice somewhat Torque transmission along with maximum permissible parallel and angular

misalignment values are the dominant considerations Most couplings will publish these values and

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

Jaw Curved and Straight Jaw couplings are used for both motion control and light power transmission

applications and consist of pairs of multi-jawed hubs that mate with elastomeric spiders The design

allows for backlash-free torque transmission Accommodation for

parallel misalignment usually approaches 001 inch and angular

misalignment about 1 degree Elastomeric spiders give these couplings

some damping capacity and of often the spiders are available in different

durometers to lend specific properties to the individual couplings These

couplings often operate without lubricant and can transmit torque up

into the 1000 inch-lb range

Diaphragm Diaphragm couplings are generally used for high power

transmission such as found in turbomachinery Typically

they employ one or more flexible metal convoluted discs

which transmit power to an inner spacer shaft then back

out through another diaphragm stack to the driven

machinery A principal advantage over gear type

couplings is their lack of lubrication requirements

Diaphragm couplings are capable of high torque

transmission and high speed operation

Disc Disc couplings use single or multiple discs and single or double

stages which bolt to the shaft hubs They are used for power

transmission and rely on the flexibility of their thin metal discs to

transmit torque and accommodate angular misalignment They are

not especially good at managing parallel misalignment They are capable of transmitting high torques

and are often used to couple high horsepower motors gas turbines etc to loads

Gear Gear couplings also transmit high torques They have misalignment

capabilities generally about 001-002 inch in parallel and 2 degrees in

angular Gear couplings are often used in pairs with spacer shafts to

span the distance between driving and driven equipment They

generally require lubricant although some designs intended for lighter

duty use lubricant free nylons or other polymers for the center sleeve

Grid Grid couplings employ spring like connecting elements that weave

between slots machined in the coupling hubs They are capable of high

torque transmission with an added bonus of shock absorption and

torsional vibration dampening They operate without lubricant They are

appropriate for power transmission and capable of handling parallel

misalignment up to 030 inch and angular misalignment of about frac14 degree

Oldham Oldham couplings handle high degrees of parallel

misalignment owing to their sliding element design Use of

an elastomer center element instead of metal is popular in

modern versions Some manufactures claim an ability to

tolerate up to 5 degree angular misalignment through the

use of cylindrical rather than rectangular sliders

Schmidt Schmidt couplings

are designed specifically to operate on shafts that are offset They

arenrsquot flexible couplings in the strictest sense which are designed

to accommodate slight misalignment in shafts that are

theoretically parallel and square to one another Schmidt couplings

are used in papermaking printing and similar machines and

function more like a 11 gearbox in

a more compact space

Clamping Rigid one- and two-piece Clamping couplings lack accommodation for

shaft misalignment and are popular for slow or intermittent shafting

arrangements where alignment is not of concern They are the simplest

form of shaft coupling and apart from their lack of misalignment

tolerance are inexpensive zero-backlash devices

Other couplings Coupling designs are many only the principal ones are detailed above Other coupling types include

meshing tooth or Hines designs pin and bush couplings and spline couplings

Applications and Industries Couplings correct for an inability to produce or maintain

perfect alignment in coupled machines Some machines

dispense with the need for couplings by running close

coupled meaning that the bearings of the motor support

an extended shaft upon which the rotating component of

the driven equipmentmdasha pump impeller for instance---

mounts The

motor and

pump at right is

an example of a

close-coupled

machine Where this is practical to do it is done to dispense

with he alignment problem Often though the machines

require their own bearings and as a result a need to connect

their independent shafts The diagram above shows the two

misalignments that can be expected parallel or offset (top)

and angular (bottom)

For some couplings backlash is an important concern Motion control applications where position of the

driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash

coupling to assure that no slop exists in the system Backlash is a lesser concern for most power

transmission applicationsmdashpumpsmotors for instancemdashwhere efficient torque transmission is the

primary objective Here misalignment can lead to higher energy use accelerated bearing wear

excessive vibration etc

Both the beam and the bellows couplings offer zero backlash and are frequently used for transferring

the relatively small torques of motion control

For power transmission generally all-metal couplings such as the gear and disc designs are capable of

transmitting higher torques than those that use elastomeric elements such as jaw couplings

Although couplings are designed to accommodate misalignment they arenrsquot substitutes for aligning

machines during installation

Considerations In selecting couplings a designer first needs to consider motion control varieties or power transmission

types Most motion control applications transmit comparatively low torques Power transmission

couplings in contrast are designed to carry moderate to high torques This decision will narrow

coupling choice somewhat Torque transmission along with maximum permissible parallel and angular

misalignment values are the dominant considerations Most couplings will publish these values and

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

Grid Grid couplings employ spring like connecting elements that weave

between slots machined in the coupling hubs They are capable of high

torque transmission with an added bonus of shock absorption and

torsional vibration dampening They operate without lubricant They are

appropriate for power transmission and capable of handling parallel

misalignment up to 030 inch and angular misalignment of about frac14 degree

Oldham Oldham couplings handle high degrees of parallel

misalignment owing to their sliding element design Use of

an elastomer center element instead of metal is popular in

modern versions Some manufactures claim an ability to

tolerate up to 5 degree angular misalignment through the

use of cylindrical rather than rectangular sliders

Schmidt Schmidt couplings

are designed specifically to operate on shafts that are offset They

arenrsquot flexible couplings in the strictest sense which are designed

to accommodate slight misalignment in shafts that are

theoretically parallel and square to one another Schmidt couplings

are used in papermaking printing and similar machines and

function more like a 11 gearbox in

a more compact space

Clamping Rigid one- and two-piece Clamping couplings lack accommodation for

shaft misalignment and are popular for slow or intermittent shafting

arrangements where alignment is not of concern They are the simplest

form of shaft coupling and apart from their lack of misalignment

tolerance are inexpensive zero-backlash devices

Other couplings Coupling designs are many only the principal ones are detailed above Other coupling types include

meshing tooth or Hines designs pin and bush couplings and spline couplings

Applications and Industries Couplings correct for an inability to produce or maintain

perfect alignment in coupled machines Some machines

dispense with the need for couplings by running close

coupled meaning that the bearings of the motor support

an extended shaft upon which the rotating component of

the driven equipmentmdasha pump impeller for instance---

mounts The

motor and

pump at right is

an example of a

close-coupled

machine Where this is practical to do it is done to dispense

with he alignment problem Often though the machines

require their own bearings and as a result a need to connect

their independent shafts The diagram above shows the two

misalignments that can be expected parallel or offset (top)

and angular (bottom)

For some couplings backlash is an important concern Motion control applications where position of the

driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash

coupling to assure that no slop exists in the system Backlash is a lesser concern for most power

transmission applicationsmdashpumpsmotors for instancemdashwhere efficient torque transmission is the

primary objective Here misalignment can lead to higher energy use accelerated bearing wear

excessive vibration etc

Both the beam and the bellows couplings offer zero backlash and are frequently used for transferring

the relatively small torques of motion control

For power transmission generally all-metal couplings such as the gear and disc designs are capable of

transmitting higher torques than those that use elastomeric elements such as jaw couplings

Although couplings are designed to accommodate misalignment they arenrsquot substitutes for aligning

machines during installation

Considerations In selecting couplings a designer first needs to consider motion control varieties or power transmission

types Most motion control applications transmit comparatively low torques Power transmission

couplings in contrast are designed to carry moderate to high torques This decision will narrow

coupling choice somewhat Torque transmission along with maximum permissible parallel and angular

misalignment values are the dominant considerations Most couplings will publish these values and

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

Applications and Industries Couplings correct for an inability to produce or maintain

perfect alignment in coupled machines Some machines

dispense with the need for couplings by running close

coupled meaning that the bearings of the motor support

an extended shaft upon which the rotating component of

the driven equipmentmdasha pump impeller for instance---

mounts The

motor and

pump at right is

an example of a

close-coupled

machine Where this is practical to do it is done to dispense

with he alignment problem Often though the machines

require their own bearings and as a result a need to connect

their independent shafts The diagram above shows the two

misalignments that can be expected parallel or offset (top)

and angular (bottom)

For some couplings backlash is an important concern Motion control applications where position of the

driven equipment is precisely tied to the position of a servo- or stepper motor rely on zero-backlash

coupling to assure that no slop exists in the system Backlash is a lesser concern for most power

transmission applicationsmdashpumpsmotors for instancemdashwhere efficient torque transmission is the

primary objective Here misalignment can lead to higher energy use accelerated bearing wear

excessive vibration etc

Both the beam and the bellows couplings offer zero backlash and are frequently used for transferring

the relatively small torques of motion control

For power transmission generally all-metal couplings such as the gear and disc designs are capable of

transmitting higher torques than those that use elastomeric elements such as jaw couplings

Although couplings are designed to accommodate misalignment they arenrsquot substitutes for aligning

machines during installation

Considerations In selecting couplings a designer first needs to consider motion control varieties or power transmission

types Most motion control applications transmit comparatively low torques Power transmission

couplings in contrast are designed to carry moderate to high torques This decision will narrow

coupling choice somewhat Torque transmission along with maximum permissible parallel and angular

misalignment values are the dominant considerations Most couplings will publish these values and

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

using them to refine the search should make picking a coupling style easier Maximum RPM is another

critical attribute Maximum axial misalignment may be a consideration as well Zero backlash is an

important consideration where feedback is used as in a motion control system

Some power transmission couplings are designed to operate without lubricant which can be a plus

where maintenance is a concern or difficult Lubricated couplings often require covers to keep the

grease in Many couplings including chain gear Oldham etc are available either as lubricated metal-

on-metal varieties and as metal and plastic hybrids where usually the coupling element is made of nylon

or another plastic to eliminate the lubrication requirements There is a reduction in torque capacity in

these unlubricated forms compared to the more conventional designs

Important Attributes

Coupling Style Most of the common styles have been described above

Maximum RPM Most couplings have a limit on their maximum rotational speed Couplings for high speed turbines

compressors boiler feed pumps etc usually require balanced designs andor balanced boltsnuts to

permit disassembly and reassembly without increasing vibration during operation High speed couplings

can also exhibit windage effects in their guards which can lead to cooling concerns

Max Transmitted Horsepower or Torque Couplings are often rated by their maximum torque capacity a measurable quantity Power is a function

of torque times rpm so when these values are stated it is usually at a specified rpm (5HP at 100 rpm for

instance) Torque values are the more commonly cited of the two

Max Angular Misalignment Angular misalignment capacity is usually stated in degrees and represents the maximum angular offset

the coupled shafts exhibit

Max Parallel Misalignment Parallel misalignment capacity is usually given in linear units of inches or millimeters and represents the

maximum parallel offset the coupled shafts exhibit

Max Axial Motion Sometime called axial misalignment this attribute specifies the maximum permissible growth between

the coupled shafts given generally in inches or millimeters and can be caused by thermal effects

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

Related Product Categories UniversalConstant Velocity Joints are mechanical assemblies composed of rotating and

pivoting components that permit large angular displacement between rotating input and output

shafts

Shaft Coupling Aligners are mechanical or electro-mechanical instruments that measure

misalignment between coupled rotating equipment such as motors and pumps

Resources

General Disc Couplings White Paper

httpwwwrexnordcomsitesProcessDocumentsCP4-00420XTSR20White20Paperpdf

Clamping Couplings for Motion Control

httpwwwrulandcompdfRigid_Couplings_Articlepdf

Online Coupling Handbook

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Coupling Preselection Guide

httpwwwlovejoy-inccomthecouplinghandbook_part1aspx

Couplings Tutorial

httpturbolabtamueduprocturboprocT18T18141-164pdf

Chain Couplings

httpptptsubakimotocojpcontentse_bookcatarogkikCHAIN_COUPLINGSpageviewpageviewht

mlpage_num=0

Manufacturers and Suppliers httpcadtimkencomcategorypower-transmission-products

httphoustonbearingthomasnet-navigatorcom

httplabglasskimble-chasecomcategoryadapters-2

httpclutches-torque-limitersherseyclutchcomviewitemsrigid-shaft-couplingsmodel-rc-rigid-shaft-

couplings

httpcouplingsrenbrandtcom

httpcataloge-jpccomcategoryflexible-couplingsampbc=1007C1330

httpscicouplingsthomasnetcom

httpfcmasonthomasnetcomcategorycouplings-inserts

httpcatalogclimaxmetalcomcategoryrigid-couplings

httpmeccomthomasnetcomviewitemspower-transmissiondynaflex-couplings

httpcataloglovejoy-inccomcategorycouplings-power-transmission

httpcasesrplucecomcategoryhelical-flexible-couplings-2

httponlinecatalogtpa-uscomcategoryshaft-couplings

httpcatalogrowlandcompanycomcategoryflexible-couplings

httpproductsrpmmechcomviewitemsdynaflex-174-elastomeric-couplingsdynaflex-174-shear-

type-couplingsampbc=100|1001|1106

httpcatalogmachinecompcomcategoryslip-couplings

httpcookindustrialthomasnetcomcategoryelectric-motors-accessories-power-transmission

httpcatalogdaltongearcomcategory-overload-safety-devices-torque-limiters-couplings

httpindustrial-suppliescadencesupplycomcategoryshaft-couplings