SIZING AND SELECTION INDUSTRIAL DRIVE COUPLINGS ST

Symbols

TAR
     Disengagement torque of the coupling (Nm)
K
     Service factor
Tmax
     Maximum torque of the drive system (Nm)
TAN
     Rated torque of the motor (Nm)
PDrive     Drive power (kW)
n
     Drive speed (min-1)

     Angular acceleration
t
     Acceleration time (s)   1/s²
JL     Moment of inertia of load (kgm2)
JA     Moment of inertia of drive (kgm2)
TAS     Peak motor torque (Nm)
S     Number of safety elements
F     Tangential force (kN)
r     Radius to element (m)
s     Spindle pitch (mm)
Fv     Feed force (N)
η     Spindle efficiency 
d0     Pitch diameter (mm)
Fv     Feed force (N)
CT     Torsional stiffness of coupling (Nm/rad)
JMasch.     Total load inertia (kgm2)
     (e.g. shaft + sprocket + chain + roller + 1/2 of coupling) 
JMot.     Total driving inertia (kgm2)
fe     Resonant frequency of the two mass system (Hz)

     

According to disengagement torque

Safety couplings are normally selected according to the required disengagement torque, which must be greater than the maximum torque required for start-up and operation.


Disengagement torque values are often determined from the drive data and are typically a multiple of the nominal torque at the operating drive speed (TAN). In addition to a start-up torque (TMAX), the following values are used as further safety factors, depending on the load conditions:


K = 1.3 uniform harmonious load
K = 1.5 non-uniform load
K = 1.8 heavy shock load

According to resonant frequency

The torsional natural frequency of the coupling must be significantly higher or lower than that of the equipment. For the mechanical substitution model the two mass system applies

Load factors by machine type

EXCAVATORS
S bucket chain excavators
S travelling gear (caterpillar)
M travelling gear (rails)
M suction pumps
S bucket wheels
M slewing gears

CONSTRUCTION MACHINERY
M concrete mixers 
M road construction machinery

CHEMICAL INDUSTRY
M mixers
G agiators (light fluis) 
M dryer drums
G centrifuges

FEEDERS AND CONVEYORS
S belt conveyors
G belt conveyors (bulk materials)
M belt bucket conveyors
M screw conveyors

M circular conveyors
M hoists






BLOWERS AND FANS1
G blowers (axial/radial) P:n ≤ 0,007
M blowers (axial/radial) P:n ≤ 0,007
S blowers (axial/radial) P:n ≤ 0,007
G cooling tower fans P:n ≤ 0,007
M cooling tower fans P:n ≤ 0,007
S cooling tower fans P:n ≤ 0,007

GENERATORS AND TRANSFORMERS
S generators

RUBBER MACHINERY
S extruders

S calendars
M mixers

S rolling millse

WOOD PROCESSING MACHINERY
G woodworking machines

CRANES
S travelling gears 
S hoisting gears
M slewing gears

PLASTIC MACHINERY
M mixers
 
M shredders

METALWORKING MACHINERY
M sheet metal bending machines
S plate straightening machines



  S presses
  M shears

  S punch presses

  M machine tools, main 

  FOOD PROCESSING MACHINERY
  G filling machines

  M kneading machines

  M cane crushers 

  M cane cutters 
  S cane mills

  M sugar beet cutters
  M sugar beet washers

  PAPER MACHINERY
  S wood cutters
  S calendars

  S wet presses
  S suction presses 
  S suction rollers
  S drying cylinders

  PUMPs
  S piston pumps 
  G centrifugal pumps (light fluids) 
  S reciprocaating pumps

  STONE AND CLAY MACHINES
  S breakers



S rotary kilns

S hammer mills 
S brick presses

TEXTILE MACHINERY
M tanning vats
M willows
M looms

COMPRESSORS
S reciprocating  compressors
M centrifugal compressors

METAL ROLLING MILLS
M plate tilters 
S ingot handling machinery
M winding machines (strip and wire)
S descaling machines
S cold rolling mills

M chain transfers

M cross transfers

M roller straighteners

S tube welding machines

S continuous casting plants
M roller adjustment drives

LAUNDRY MACHINES
M tumblers
M washing machines

WASTEWATER TREATMENT PLANTS
M aerators
G screw pumps



According to torque

1. Calculate the drive torque TAN.

 


2. Base the coupling rated torque TKN on the drive torque TAN multiplied by the application factors.

Ratings chart

Maximum torque, speed and misalignment are related and can not exist at the same time.

Evaluation T/TKN and n / nmax
Compare plotted values for combined limits.