A three-dimensional fluid-solid coupling mathematic model of a cone-pore-combined mechanical seal was established by considering interactions of pressure distribution change of fluid film between two end faces and stress deformation of sealing rings. A numerical iteration method was developed to solve the coupling model so as to obtain pressure distribution of the fluid film and surface deformation. The influence of structural parameters of the tapered end face on sealing performance was analyzed at various working conditions. The results showed that diamond-shaped pores created dynamic pressure effect

which produced circular and radial wave deformation at the end faces

and static pressure effect

which changed impact accordingly within the end face region with the increase of taper Ф and cone width ratio γ. The convergent seal of the tapered end face at Ф=5-6 or Ф=2-4 and γ=0.8-1.0 should be selected for low pressure and low to medium speed equipment. The convergent seal of the cone end face at Ф=2-3 and γ=1.0 or γ=0.2 should be selected for high pressure and high speed equipment. Changing tapered end face structure could effectively modify characteristic parameters of the cone-hole combined mechanical seal and automatically adjust seal performance during operation

which is especially suitable for variable work conditions. In addition

the change of balance coefficient B and film thickness h caused by structure change of the tapered end face could made up defects of small dynamic pressure effect at low speed to achieve large opening force and could also work under large h so that the flatness and polish requirement for seal end face might be reduced.