| 摘要 |
<p>Rotary mechanical face seal of the type comprising, with reference to figure 1, a seal seat (21) mounted to and sealed with a housing (2) and a ring face (31) of a ring element (3) surrounding a shaft (1). Ring face (31) is adapted, in the operating position of the ring element (3), to bear against a seat face (22) of the seal seat (21) to provide a primary seal interface (22/31) therebetween. In apparatus according to the invention ring element (3) is mounted to the (1) by means permitting translational movement of the ring face (31) towards or away from the seat face (22), for example by means of a drive ring (4) mounted to the shaft and having an annular recess for receiving ring element (3) a seal being provided between the drive ring and the ring element by O-rings (52, 53) grooved in the drive ring. In order for ring element (3) to move away from its operating position it must displace a non-compressible fluid from a sealed chamber, defined between ring element (3) and its mounting means (4, 52, 53), via a restricted aperture (8). In preferred embodiments restricted aperture (8) communicates with the seal face (31). Also highly preferred are arrangements in which net forces acting on ring element (3) to cause it to bear on the seat face act on a surface which is of small area in comparison with the primary seal interface area. </p> |
