Balanced mechanical seal assembly.

摘要

A mechanical seal assembly is disclosed in which the seal faces of the primary seal members remain essentially perpendicular to the shaft of the equipment being sealed regardless of any misalignment between the shaft and the equipment. The seal assembly has a sleeve (20) for mounting on the shaft (12), the sleeve providing a support structure wherein all primary seal member faces (46, 46 min ) are aligned with respect to this support structure regardless of loading. The primary seals are uniformly and persistently urged toward the support structure, without sliding parts, by the combination of net hydraulic pressure at the mated seal faces plus steady bias from a minimally flexing biasing source, such as compression springs, at one end of the sleeve. In a double balanced double seal embodiment, a piston area (A, B) is defined on the rear of each primary seal member. Each primary seal piston area and the seal face contact area of the associated mated primary seals is determined without regard to location or thickness of secondary seals. Each piston area is a predetermined fixed area equal to a major portion of the associated primary seal face contact area.