TP50-40/4 Shaft Seals Manual

9
Shaft seals in general
Shaft seals
Seal balancing
Calculation formulas
Formula for calculation of the balancing K-factor:
Formula for calculation of the closing force (F
C
):
Formula for calculation of the opening force (F
O
):
Formula for calculation of the efficient closing force
(F
C,eff.
):
Formula for calculation of the efficient seat load (P
eff.
):
Key to symbols:
Calculation example, unbalanced shaft seal,
Grundfos type B
Fig. 8
Grundfos shaft seal, type B
Data:
Calculation of the balancing K-factor:
Calculation of forces acting on the shaft seal:
Calculation of the closing force (F
C
):
Calculation of the opening force (F
O
):
Calculation of the efficient closing force (F
C, eff.
):
Calculation of the efficient seat load (P
eff.
):
Calculation example, balanced shaft seal, Grundfos
type H
Fig. 9
Grundfos shaft seal, type H
Data:
Calculation of the balancing K-factor:
Calculation of forces acting on the shaft seal:
Calculation of the closing force (F
C
):
Calculation of the opening force (F
O
):
Symbol Description Note
A Area in mm
2
See sketch of balanced and
unbalanced shaft seal, see
page 8.
B Area in mm
2
See sketch of balanced and
unbalanced shaft seal, see
page 8.
P
Pressure around shaft seal
in N/mm
2
F
S
Spring force in N
TM00 2581 4593
A 180 mm
2
B 150 mm
2
F
S
45 N
P0.8 N/mm
2
K
A
B
----
=
F
C
AP×()F
S
+=
[N]
F
O
B
P
2
----
×=
[N]
F
C, eff.
F
C
F
O
–=
[N]
P
eff.
F
C, eff.
B
--------------------
=
[N/mm
2
]
TM02 7100 2603
A 150 mm
2
B 150 mm
2
F
S
45 N
P 0.8 N/mm
2
K
180
150
----------
=
K = 1.2
F
C
180 0.8×()45+=
F
C
189 [N]=
F
O
150
0.8
2
--------
⎝⎠
⎛⎞
×=
F
O
60 [N]=
F
C, eff.
189 60–=
F
C, eff.
129 [N]=
P
eff.
129
150
----------
=
P
eff.
0.86= [N/mm
2
]
K
150
150
----------
=
K = 1.0
F
C
150 0.8×()45+=
F
C
165 [N]=
F
O
150
0.8
2
--------
⎝⎠
⎛⎞
×=
F
O
60 [N]=