Oy Safematic Ltd.

Safematic Gmbh

Esko Lopperi

Markku Lummila

Esa Salovaara

Juhani Kuusela

Esko Poikolainen

Juhani Ljokkoi

PerttinaHarri

Tuomo Suhonen

Pertti Saksala

The invention relates to an arrangement in a mechanical seal. The mechanical seal comprises a seal member to be attached to a rotating machine part and provided with a slide ring; and a static seal member to be attached to a stationary machine part and provided with a slide ring. The mechanical seal further comprises connections for supplying flushing liquid to the seal and for discharging it from the seal; and a secondary seal arranged to seal the gap between the rotating machine part and the static seal member. In order to achieve a simple seal reliable in operation, a choke is formed in the flow conduit of the supply connection for flushing liquid, the choke communicating by means of a suction connection with a space receiving the flushing liquid leaking across the secondary seal. The flushing liquid flowing in the supply connection creates, in a manner known per se, a vacuum in the choke, which vacuum is arranged to suck the flushing liquid leaking across the secondary seal through the suction connection into the supply connection.

Liquid-flushed seal for rotating shaft with vacuum providing leakage

The invention relates to a slide ring seal for sealing a shaft rotatable with respect to a wall, which seal comprises a body portion and seal rings provided with slide rings, which seal rings are so arranged with respect to each other that the sealing slide faces of the slide rings are pressed against each other and rotate with respect to each other. Each slide ring is fastened in the seal ring thereof by a shrink fit, whereby the peripheral face of the slide ring is in engagement with a face provided on the seal ring, so that the radial press force of the shrink fit is directed to act on a centroid of the cross-sectional area of the slide ring. In order to ensure that the forces of the shrink fit keep acting accurately on the centroid of the cross-sectional area of the slide ring, at least one of the faces which are in engagement with each other in the shrink fit is convex. The highest point of the convex surface is in a radial plane extending through the centroid of the cross-sectional area of the slide ring.

Slide ring seal

The invention relates to a slide-ring seal which comprises a frame portion provided with connections for a sealing liquid and seal rings (4) provided with slide rings (5). Each slide ring (5) is thereby fastened in place by means of a shrinkage fit. In order to provide a better wearability and a better sealing effect, each seal ring (4) is formed by two ring portions (7, 8) which are fastened on each other by means of a radial shrinkage fit. The slide ring (5) is essentially L-shaped in cross-section so that the slide ring is provided with at least two supporting surfaces (9, 10) extending in parallel with the sliding surface. A radial clearance (11) is provided between the outer periphery of the slide ring (5) and the inner surface of the seal ring (4). The supporting surfaces (9, 10) of the slide ring (5) are supported on the seal ring (4), whereby the slide ring (5) is fastened on the seal ring (4) solely by an axial press fit.

Slide-ring seal

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Jyvaskyla, Finland

Esko Lopperi