Patent ID: 6325382
Filing Date: 2001-12-04
Classification: F16J

Abstract:
A non-contact type mechanical seal comprising:a cylindrical seal case mounted about a horizontally extending rotary shaft of a rotary machine, said seal case having at a first end an opening into an inside region of the machine,a non-rotatable stationary seal ring disposed at a second end of said seal case and movable in an axial direction;a rotary seal ring provided on an inside region side of the stationary seal ring and clamped on said rotary shaft, said rotary shaft passing through said seal case and said stationary seal ring;thrusting means for pressing said stationary seal ring toward said rotary seal ring; and,a static pressure generating mechanism for generating static pressure between opposed seal faces of the rotary and stationary seal rings,wherein a labyrinth seal is provided between said seal case and said rotary shaft, said labyrinth seal comprising a plurality of annular grooves disposed side by side in said axial direction on an inner circumferential portion of said seal case at said first end and a plurality of annular plates disposed side by side in said axial direction on an outer circumferential portion of said rotary shaft, the annular plates extending into the annular grooves, thus partitioning a region on an outer diameter side of said opposed seal faces within said seal case from said inside region of said rotary machine.