The mechanical seal device comprises a rotating unit (11) and a stationary unit (12) respectively comprising a ring of ceramic material (13, 15) associated with the bottom of a support element (14, 16) of polymeric material shaping a respective sealing face. The rotating unit (11) and the stationary unit (12) are suitable to be coaxially mounted on a shaft (8) of a rotating member (3), in specular position, so that said rings (13, 15) of ceramic material have said seal faces in mutual contact on a plane substantially perpendicular to the axis of the shaft (8).

In an exemplary embodiment, a mechanical seal for sealing a fluid flowing outwardly radially from sliding surfaces S where a stationary ring 221 and a rotating ring 211 slide against each other, includes: a bellows 222 interposed between the stationary ring 221 and a stationary wall 226; a case member 223 for holding an outer cylindrical part 222c of the bellows 222 to the stationary ring 221; and a holding member 224 fitted to an inner cylindrical part 222a of the bellows 222, and having an axial length substantially equal to a length fitted to the inner cylindrical part 222a, wherein the bellows 222 has a curved part 222b between the outer cylindrical part 222c and the inner cylindrical part 222a, and the case member 223 is provided with a wall part 223a covering the entire periphery of the radial outer side of the curved part 222b.

In an exemplary embodiment, a mechanical seal for sealing a fluid flowing outwardly radially from sliding surfaces S where a stationary ring 221 and a rotating ring 211 slide against each other, includes: a bellows 222 interposed between the stationary ring 221 and a stationary wall 226; a case member 223 for holding an outer cylindrical part 222c of the bellows 222 to the stationary ring 221; and a holding member 224 fitted to an inner cylindrical part 222a of the bellows 222, and having an axial length substantially equal to a length fitted to the inner cylindrical part 222a, wherein the bellows 222 has a curved part 222b between the outer cylindrical part 222c and the inner cylindrical part 222a, and the case member 223 is provided with a wall part 223a covering the entire periphery of the radial outer side of the curved part 222b.

A hydrostatic seal configured to be disposed between relatively rotatable components. The hydrostatic seal includes a seal carrier. The hydrostatic seal also includes a beam extending axially from a forward end to an aft end, the beam cantilevered to the seal carrier at one of the forward end and the aft end, the beam free at the other end. The hydrostatic seal further includes a bellows seal operatively coupled to the seal carrier and in contact with the beam.

A hydrostatic seal configured to be disposed between relatively rotatable components. The hydrostatic seal includes a seal carrier. The hydrostatic seal also includes a beam extending axially from a forward end to an aft end, the beam cantilevered to the seal carrier at one of the forward end and the aft end, the beam free at the other end. The hydrostatic seal further includes a bellows seal operatively coupled to the seal carrier and in contact with the beam.

A mechanical seal assembly adapted for arrangement around a rotating shaft of a pump has first and second seals. Both include primary and mating rings, biasing mechanisms and annular flexible sealing membranes. The two seals can have different seal balances or different biasing forces (or both) to allow the second seal to run dry for extended periods.

A mechanical seal assembly adapted for arrangement around a rotating shaft of a pump has first and second seals. Both include primary and mating rings, biasing mechanisms and annular flexible sealing membranes. The two seals can have different seal balances or different biasing forces (or both) to allow the second seal to run dry for extended periods.

A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

A non-collapsible flexible sealing membrane (or bellows) for incorporation in a mechanical seal assembly and use in rotary shaft equipment. The sealing membrane includes a substantially radially outward extending first flange portion, which can be urged into an axially shiftable ring by a biasing mechanism. The sealing membrane further includes a substantially axially outboard extending second coaxial portion, substantially radially inward of the balance diameter of the seal. The horizontal portion is advantageously held fixed to a stub sleeve by an annular band. The angle between the vertical portion and the horizontal portion of sealing membrane enables directional control of the forces acting on stub sleeve and primary ring.

A maintenance-free bearing system having self-lubricating features, seals, grooves and slots for use in a cushion hitch assembly for a hitch pull scraper vehicle. An interconnected bearing linkage system having two or more horizontal two-axis combined journal and thrust bearings with self-lubricating liners therein, two or more vertical single-axis sleeve bearings with self-lubricating liners therein and one or more vertical thrust bearing with self-lubricating liners therein, that cooperate with one another to accommodate vertical and horizontal angular movement relative to one another. The vertical thrust bearings incorporate an outer seal assembly and/or an inner seal assembly with a tapered configuration that improves retention of the seal assembly during rotation.