Shaft seal arrangement for a ship bulkhead

摘要

A seal arrangement for sealing around a rotating shaft that passes through a ship bulkhead includes an expandible and contractible seal ring made of several seal ring segments, and radial actuators that engage the seal ring segments and can be power-activated, e.g. with a pressure medium, to pull the seal ring segments radially outwardly, thereby expanding the seal ring to a larger diameter spaced away from the shaft. When the radial actuators are not activated, the biasing force of springs contracts the seal ring segments to a smaller diameter, to establish sealing contact of the seal ring on the shaft. In normal operation a control unit activates the actuators, but if sensors detect a power failure or water in the ship, or a manual switching is triggered, then the seal arrangement contracts under spring force into the sealing condition with the seal rings sealing against the shaft.

主权项

1. A seal arrangement for providing a seal around a shaft extending through an opening in a bulkhead, comprising:
a seal ring that comprises plural seal ring segments and has an inner diameter which can be adjusted by moving said seal ring segments radially outwardly and radially inwardly relative to an axis of said seal arrangement; a housing that supports said seal ring and is adapted to be mounted on the bulkhead around the opening of the bulkhead; plural power-activatable radial actuators that are carried by said housing circumferentially distributed about said axis, and are coupled to said seal ring segments; at least one spring that is coupled to and applies a radially inward spring-bias to said seal ring segments or to said radial actuators, wherein said at least one spring includes a first spring; and a pressure ring arranged between said seal ring and said first spring, wherein said pressure ring has a radially inwardly protruding guide ridge, said seal ring has a radially outwardly facing guide groove that receives said guide ridge therein, and said guide ridge and said guide groove have mutually cooperating guide surfaces that slope conically about said axis and cause an axially directed guide force due to radially directed relative motion of said guide ridge in said guide groove; wherein, in an installed condition, said seal ring encircles the shaft, said radial inward spring-bias of said at least one spring urges said seal ring segments radially inwardly into sealing contact on the shaft whereby said inner diameter of said seal ring matches an outer diameter of the shaft, and said radial actuators when activated are operative to pull said seal ring segments radially outwardly away from the shaft against said radial-inward spring bias so that said inner diameter of said seal ring becomes larger than the outer diameter of the shaft.