Patent ID: 6616145
Filing Date: 2003-09-09
Classification: F16J

Abstract:
A face seal device for use with a rotary component rotating at a high rotational speed, comprising:a non-rotating face seal ring; and a rotary face seal ring, wherein said rotary face seal ring is mounted in a loose fit on the rotary component for rotation therewith, wherein said rotary face seal ring comprises a sealing face which, in operation, is essentially radially aligned for cooperation with an opposite sealing face of said non-rotating face seal ring, wherein said rotary face seal ring is formed of at least two sub-portions comprising a base portion and an extension portion, wherein the extension portion provides an additional mass and has an areal center of gravity axially spaced from an areal center of gravity of the base portion, and wherein an axial spacing between the areal centers of gravity and the mass of the extension portion satisfies the following equation: m*z=k*10-2*Î”&it;â€ƒ&it;T*(D-d)*b2r*n2*qk=Î±*E,wherek=&agr;*E, where q is in a range between 0.5 and 2.0, and where&Dgr;T =the temperature difference between the sealing face and anouter end face of said rotary face seal ring,n =the rotational speed of said rotary face seal ring,D =the external diameter of the base portion,d =the internal diameter of the base portion,b =the width of the base portion,E =the modulus of elasticity of the material of said rotary face sealring,&agr; =the co-efficient of thermal expansion of the material of saidrotary face seal ring,r =the radial spacing between the areal center of gravity of theextension portion and the central longitudinal axis of the faceseal device,z =the mutual axial spacing between the areal centers of gravity,m =the mass of the extension portion,whereby a torque directed towards said non-rotating face seal ring acts on said rotary face seal ring in correspondence with centrifugal forces resulting due to the extension portion and the axial spacing between the areal centers of gravity.