Seepex BN 5-12 Series, Operation & Maintenance Manual

Page: 39 / 309

14
The pin joint in detail.
Optimum NPSH value
Our pumps are equipped with two joints, to enable the eccen-
tric motion of the rotor and to transfer the rotation by means
of the coupling rod from the plug-in shaft to the rotor. The
joint design is optimized with respect to fluid mechanics, such
that a lower NPSHR value is attained by avoiding turbulence
or restrictions in the suction casing.
Wear resistant components
This joint is made from only a few wear resistant, hardened
and exchangeable joint components. It is fastened by means
of a retaining sleeve on the rotor head, the plug-in shaft head,
or the drive shaft head. Tight manufacturing tolerances ensure
that the pump runs quietly and smoothly and are crucial for
longer service life.
Replacing individual components
Our standard joint is characterized by the fact that the connec t -
ing element, the coupling rod pin, is guided in a hardened,
replaceable bushing. In case of need, the coupling rod or the
guide bushing can be replaced separately. In this case, the
main components – the rotor, the coupling rod and the plug-in
shaft – need not be replaced.
Flexible full sealing
The entire joint, which is filled with special grease, is sealed
with a flexible universal joint sleeve. The joint sleeve is fas -
ten ed to the rotor head, the plug-in shaft head, or the drive
shaft head and to the coupling rod by means of holding bands.
a Small holding band
b Large holding band
c Universal joint sleeve
1 Coupling rod
2 Coupling rod bushing
3 Retaining sleeve
4 Coupling rod pin
5 Guide bushing
6 Plug-in shaft
Universal joint sleeve
protection made of steel
Pin joint with joint seal, fully assembled
Coupling rod Plug-in shaft
Fluid-tight design for long-term operation
The joint is thus optimally protected against penetration by the
usually abrasive product being pumped. This gas-tight and
fluid-tight design has proven its worth above all for continuous
operation.
Joint seal withstands high pressure
In the case of high inlet pressure in the suction casing or in
the case of clockwise pumps with a high pressure range (great-
er than 3 bar (45 PSI) to max. 12 bar (180 PSI)), the joint sleeves
are stabilized by an interior sleeve. In the pressure range from
12 to 24 bar (180 to 360 PSI), complete filling of the joint with
special grease is ensured by means of additional grease filling
holes in the coupling rod. This prevents any
deformation of the universal joint sleeve by the high pressure.
Material protection
To protect the joint sleeve from mechanical damage caused
by oversize solids such as plastic, wood or metal, we offer a
universal joint sleeve made of steel.
Key advantages
•
Few components and easy to assemble
•
Wear resistant with thus long service life, due to
hardened components
•
Optimum protection of the joints by complete sealing