Bearing performance of a mechanical seal with tapered film
Diameter 2R0
10
-3
m
Diameter 2R1
10
-3
m
Film thickness h0
10
-6
m
Film thickness h1
10
-6
m
Supply pressure pS
10
6
Pa
Ambient pressure pA
10
6
Pa
Viscosity η
Pa·s
Load capacity F
'
=F/(A(pS-pA))
Flow rate Q'
Stiffness S'
Load capacity F
N
Flow rate Q
10
-6
l/min
Inherent stiffness S=-dF/dh
10
6
N/m
In
mechanical seal
technology the dimensionless load F' is called the pressure gradient factor k
1
. It's the ratio of the integrated pressure distribution F and the hydrostatic pressure pS-pA acting on the seal surface A. With parallel film k
1
=0.5 and S=0. A tapered film shows axial bearing stiffness and can be considered as a hydrostatic collar bearing.
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