Mechanical Seal

A mechanical seal, comprising a gland for being mounted on a housing, a rotating assembly for being connected with a shaft, and two stationary seal rings separately received in the gland and axially arranged between the gland and rotating assembly, with an inner wall of the gland defining a shaft bore for the rotating assembly as well as the shaft to pass through, with the rotating assembly comprising:

• a retainer having a primary ring, a plurality of first slide legs, and a plurality of second slide legs, with the primary ring being coaxial with the shaft bore and defining a first axial surface and a second axial surface at two axial ends thereof, and a plurality of spring holes communicating the said first and second axial surfaces, with the first slide legs being formed on the first axial surface and axially extending outwards while an free end of each first slide leg has a first engaging block protruding to an axial line of the shaft bore, with the second slide legs being formed on the second axial surface and axially extending outwards while an free end of each second slide leg has a second engaging block protruding to the said axial line;
• a first compression ring being coaxial with the shaft bore and formed with at least one cutaway portion at an outer periphery thereof, with the first compression ring being movably positioned between the first axial surface and the first engaging block in axial direction, and being radially surrounded by the first slide legs;
• a second compression ring being coaxial with the shaft bore and also formed with at least one cutaway portion at an outer periphery thereof, with the second compression ring being movably positioned between the second axial surface and the second engaging block in axial direction, and being radially surrounded by the second slide legs;
• a plurality of spring members separately received in the spring holes and oppositely abutting against the first and second compression rings with two ends;
• a first rotating seal ring having one end being abutted by the first compression ring, with a plurality of first notches formed in a outer periphery of the first rotating seal ring, with an amount of the first notches being not less than an amount of the first slide legs for each first slide leg to be received in and engaged with one of the first notches;
• a second rotating seal ring having one end being abutted by the second compression ring, with a plurality of second notches formed in a outer periphery of the second rotating seal ring, with an amount of the second notches being not less than an amount of the second slide legs for each second slide leg to be received in and engaged with one of the second notches;
• and
• a shaft sleeve for being connected with the shaft sequentially passing through the first rotating seal ring, first compression ring, primary ring of the retainer, second compression ring, and second rotating seal ring;
• wherein the spring members oppositely pushe the first and second rotating seal rings through the first and second compression rings, and the first and second rotating seal rings respectively abut against the two stationary seal rings to form an interface between the first rotating seal ring and one of the stationary seal rings and another interface between the second rotating seal ring and the other stationary seal ring;
• wherein a smallest distance form the axial line of the shaft bore to each cutaway portion is not larger than a distance from the said axial line to each first or second engaging block, and radiuses of the outer peripheries of the two compression rings out of the at least one cutaway portion are larger than the said distance between the said axial line and each first or second engaging block, but are not larger than a smallest distance form the said axial line to each slide leg excluded the engaging blocks;
• wherein the at least one cutaway portion of the first compression ring is mis-aligned with each first slide leg for the first compression ring to be limited between the first engaging blocks and the first axial surface, and the at least one cutaway portion of the second compression ring is mis-aligned with each second slide leg for the second compression ring to be limited between the second engaging blocks and the second axial surface.