ELECTROMAGNETIC SINGLE-DISC CLUTCHES, BRAKES
& BEARING-MOUNTED CLUTCHES.
single disc brakes
Without slip-ring, Zero Backlash, Dry operation, Simple construction
& Maintenance, Non-asbestos friction surface .
Application :- Textile, Packaging & printing machinery,
Paper-making machinery, Welding machinnery, Machine tools, Food-processing
machinery, Automation & business machinery, Book-making,
Wood processing & Watch making machinery.
Torque :- 3 N-m to 2500 N-m ............... Micro-clutches from
0.3 N-m to 3 N-m**
(** Numerous custom-built variants, especially for business
machines, copying machines, etc.)
also produce EK-ER series of single disc clutches which typically
work on the same principle as the EBA series but are characterized
by their higher flexibility due to their metallic friction
surfaces as opposed to the conventional steel-friction liner
mating surfaces. They also give a higher torque for the similar
size and more importantly can function even in wet environment
albeit with slightly reduced torque transmission capacity.
AND MODE OF OPERATION
clutches have no slip rings and are maintenance-free. An important
feature is the double magnetic flux path in the armature, which
enables the force of the magnetic field to be used twice. This gives
a high torque capacity with small physical dimensions and a relativity
friction surface are of metal, making these clutches particularly
acceptable from the environmental point of view because the organic
friction linings containing asbestos commonly found in other single-disc
clutches are eliminated. They are also suitable for wet or dry operation.
clutches need to be run-in briefly or to be operated a few times
with a speed differential before they will develop their full rated
torque. In dry operation they are unaffected by oil or grease.
diaphragm spring is used for transmitting the torque without radial
float. It is attracted to the face of the armature at 3 or 6 points
and secured to the mating component (driving or driven gearwheel,
flange, etc.). by 3 bolts.
clutch comprises a stationary magnet body containing the coil, rotor
magnet body is bolted to the machine housing whereas the rotor is
mounted on the shaft to be coupled.
rotates in the stationary magnet body with a small radial air gap.
The armature is secured to the face of the driving or driven part
by 3 bolts.
torque is transmitted by the rotor and the armature; it is unimportant
whether the rotor or armature is driving or driven, it simply depends
on the mounting arrangements of the particular application.
central alignment of the three parts (magnet body, rotor and armature)
is necessary in accordance with the tolerance stated in "Design
notes" (paragraph 4 and 5).
These single-disc clutches have metal friction faces and are suitable
for dry or wet operation. The following criteria ....affect the
choice of suitable operating conditions :
In dry operation, single-disc clutches have high torque capacities
and short operating times. The actual torque values are given in
the Selection tables. However, the friction surfaces are subject
to wear in normal use and therefore have a finite life.
Should small quantities of oil or grease contaminate the friction
surfaces in dry operation, the torque capacity will be reduced briefly
but will be regained after a few operations involving slipping.
If there is no slipping, i.e. frictional work, this self-cleaning
will not occur.
When installing a new clutch or brake the friction surfaces should
be cleaned to remove the anti-corrosion oil film applied, prior
to dispatch otherwise the stated torque values will not be attained.
If there is constant heavy contamination by oil or grease there
will be a reduction in torque capacity.
Single-disc clutches lubricated with oil or grease have lower torque
capacities and longer operating times. Provided the lubrication
is adequate according to the energy dissipation diagrams however,
they are completely free from wear therefore require absolutely
no maintenance. More detailed design notes regarding wet operation
are available on request.
2. The torque loading of the clutches is transferred to the
shaft using keys to DIN 68856, Sheet 2. In the case of small ....types
with both up to 8 mm the connection between shaft and rotor is made
by pinning, bonding or interference fit. ....The rotor must be located
axially on the shaft.
The clutch can be installed either horizontally or vertically with
the armature at the top or bottom, as required.
When clutches are used for connecting two shafts the value of
center offset must be within specified limits for ....which please
contact our design team, for your rough reference these values are
also given in the tables. If the ....required accuracy cannot be
obtained, the rotor and armature must be located centrally on one
shaft extension and ....the torque transmitted to the second shaft
extension via a flexible coupling.
radial air gap must be left between the rotor and the magnet body
otherwise both will suffer damage. This is why the stated value
of centre offset must never be exceeded. Central alignment is provided
by diameters D4 and D3 on the magnet body. It is preferable for
the central alignment to be on an anti-friction bearing in D3 enabling
the axial position of the magnet body to the rotor to be fixed at
the same time.
Central alignment of the armature is provided by the 3 fixing bolts
only. It must not be centered or located in other way. However,
it is essential for the tapped holes to be accurate in pitch and
pitch circle diameter.
Fitting the armature
armature is bolted to the mating part (flange, belt pulley, etc.)
at 3 points. There are appropriate through-holes in the diaphragm
spring and counter bores for the bolt heads; socket and screws to
DIN 84 or hexagon socket-head screws to DIN 7984/6912 should be
used. Locking of the screws to the diaphragm is impractical; they
must therefore be secured by adhesive, caulking or locknuts.
the armature is fitted, the diaphragm spring is preloaded in the
axial direction in order to produce rapid operation of the clutch.
This also ensures that the armature does not rattle or rub against
the rotor or brake disc.
preloading is unnecessary on the electromagnet types of the clutches
of sizes EK-ER 0.05 and 0.16 in special cases the sizes EK-ER 0.5
to 125 can also be used without preloading, to utilize the greater
travel and hence achieve long intervals between readjustments in
Limited external diameters with internal mounting arrangement in
applications having space constraint are also possible to suite
customer machine design requirements. VORTEX can also offer other
custom built variations for which you are requested to contact our