Siemens FLENDER K SH Series - Leakage and Leaktightness

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BA 5846 en 05/2015
9.2.1 Leakage and leaktightness
In standard "DIN 3761" information is given on the subject of leakage on gear units. Based on this and
building on the extensive experience gained at Siemens
*)
and other FVA
1)
member companies, brief
descriptions, required measures and notes on this subject are included in the following overview.
Table 16: Notes on the leaktightness of radial shaftsealing rings (RWDR
2)
)
Condition Description Measures Notes
Leaktight, dry No moisture to be seen on
radial shaft-sealing ring.
None
Leaktight, damp Film of moisture formed
functionally in the area of
the sealing edge but not
extending beyond the
bottom side of the radial
shaft-sealing ring.
Only when contaminated,
wipe with clean cloth
underneath sealing lip.
The sealing lip must not
be contaminated.
Observe.
The radial shaft-sealing
ring often dries by itself in
further operation.
No reason for complaint.
Leaktight, wet Moisture film extending
beyond the bottom side of
the radial shaft-sealing
ring but not dripping.
Wipe with clean cloth
underneath sealing lip.
The sealing lip must not
be contaminated.
Observe.
The radial shaft-sealing
ring often dries by itself in
further operation.
No reason for complaint.
Measurable leak Small trickle to be seen on
the bottom side of the
radial shaft-sealing ring,
dripping.
Change radial
shaft-sealing ring, if
necessary;
identify possible cause of
radial shaft-sealing ring
failure and rectify.
May be a reason for
complaint; one drop of oil a
day is acceptable.
Short-term leak Short-term failure of the
sealing system.
Wipe with clean cloth
underneath sealing lip.
The sealing lip must not
be contaminated.
Observe.
E.g. through small particles
on the seal edge, which
are removed again in
further operation.
No reason for complaint.
Apparent leak Temporary leak. Wipe with clean cloth
underneath sealing lip.
The sealing lip must not
be contaminated.
Due mostly to excessive
grease filling between seal
and dust lip or oil
secretions from the grease
filling of labyrinth seals.
No reason for complaint.
*
)
Siemens AG, Mechanical Drives "MD" Business Unit
1)
FVA = Forschungsvereinigung Antriebstechnik e. V.
2)
RWDR = radial shaftsealing ring
Note
Oil mist escaping from a breather valve or a labyrinth seal is functional and therefore
not a reason for complaint.