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SUN Jianjun
GU Boqin
College of Mechanical and Power
Engineering,
Nanjing University of Technology,
Nanjing 210009, China
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INVESTIGATION INTO EFFECT
OF SPRING PRESSURE ON
PERFORMANCE OF BALANCED
MECHANICAL SEALS*
Abstract: The loads acting on the
sealing elements of balanced mechanical seals are analyzed. When
the balance factor approaches the back pressure factor, the
spring pressure will become main part of the face pressure. The
leakage model of balanced mechanical seals is established on the
base of M-B model for rough surface. Several GY-70 type balanced
mechanical seals are tested. The influences of the spring
pressure both on the leakage rate and on the friction
characteristic of balanced mechanical seals are investigated.
The research results indicate that as spring pressure increases,
both the clearance between two end faces and the leakage rate
will decrease, and the friction will be more serious because
lubrication medium between the rotating ring and the stationary
ring reduces, though the increase of the spring pressure may not
be enough to change the face friction state of mechanical seals.
There exists an optimum spring pressure for mechanical seal
operation. Under this spring pres-sure, not only leakage rate is
small, but also the seal end surfaces have a fine friction
characteristic. Under different operating conditions, identical
type mechanical seals may possess different spring pressure.
Appropriate selection of spring pressure is valuable to realize
long-period and small leakage rate operating of balanced
mechanical seals.
Key words:
Balanced mechanical seal Spring pressure Leakage rate Friction characteristic
Fractal geometry
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