SIEMENS
FLENDER Standard Couplings
Introduction
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Siemens MD 10.1 · 2015
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Overview
The mechanical drive train comprises individual units such as
motor, gear unit and driven machine. The coupling connects
these component assemblies.
As well as the transmission of rotary motion and torque, other re-
quirements may be made of the coupling.
•
Compensation for shaft misalignment with low restorative
forces
•
Control of characteristic angular vibration frequency and
• damping
•
Interruption or limitation of torque
•
Noise insulation, electrical insulation
Couplings are frequently chosen after the machines to be con-
nected have already been selected. Thanks to a large number
of different coupling assembly options, specified marginal con-
ditions for clearance and connection geometry can be met from
the standard range. The coupling also performs secondary
functions, e.g. providing a brake disk or brake drum for operat-
ing or blocking brakes, devices to record speed or the attach-
ment of sprockets or pulleys.
Couplings are divided into two main groups, couplings and
clutches.
Clutches interrupt or limited the transmissible torque. The en-
gaging and disengaging forces on externally operated clutches
are introduced via a mechanically, electrically, hydraulically or
pneumatically operating mechanism. Overload, centrifugal or
freewheel clutches draw their engaging energy from the trans-
mitted output.
Rigid couplings, designed as clamp, flanged or mechanism
couplings, connect machines which must not undergo any shaft
misalignment. Hydrodynamic couplings, often also called fluid
or Föttinger couplings, are used as starting couplings in drives
with high mass moments of inertia of the driven machine. In drive
technology very often flexible, positive couplings, which may be
designed to be torsionally rigid, torsionally flexible or highly flex-
ible, are used.
Torsionally rigid couplings are designed to be rigid in a periph-
eral direction and flexible in radial and axial directions. The an-
gle of rotation and torque are conducted through the coupling
without a phase shift.
Torsionally flexible couplings have resilient elements usually
manufactured from elastomer materials. Using an elastomer ma-
terial with a suitable ShoreA hardness provides the most advan-
tageous torsional stiffness and damping for the application.
Shaft misalignment causes the resilient elements to deform.
Highly flexible couplings have large-volume (elastomer) resilient
elements of low stiffness. The angle of rotation and torque are
conducted through the coupling with a considerable phase shift.
Shaft couplings
Couplings
Clutches
G_MD10_EN_00001a
Clamp couplings
Flanged couplings
Mechanism couplings
rigid
flexible
Clutches
externally
operated
Safety couplings
torque-controlled
Centrifugal clutches
speed controlled
Freewheel clutches
Overrunning clutches
rotation direction
controlled
friction
Hydrodynamic
couplings
Magnetic
couplings
Friction couplings
positive
Torsionally rigid
Torsionally
flexible
Highly flexible
Gear couplings
All-steel membrane
couplings
Universal-joint couplings
Parallel-crank couplings
Steel-spring couplings
Pin-and-bush
couplings
Pin couplings
Rubber element
couplings
Rubber-tire
couplings
Rubber-disk
couplings
Rubber spacer ring
couplings
© Siemens AG 2015