PL183050B1 - Face seal with ferromagnetic fluid - Google Patents

Abstract

1 · A ferromagnetic fluid front seal comprising a permanent magnet, pole shoes placed in a housing and a ferromagnetic fluid filling the gaps between the pole shoes and the front surfaces of the flange on the shaft, characterized in that a seal housing (4) is placed in the housing seat (3) slidably with respect to the flange (2), and the permanent magnets (6) are radially polarized and arranged together with the pole shoes (5) on both sides of the flange (2), and furthermore, slip rings (7) are placed in the seal housing (4), the front surfaces of which are in contact with the front surfaces of the flange (2) on both sides thereof.

Description

The subject of the invention is a face seal with a ferromagnetic liquid applicable to the sealing of rotating shafts of machines and devices.

Known from the book "Gagging and gossiping technique - report, Izd. Maszinostrojenije, Moscow 1986 (page 404, fig. 11.37) ferromagnetic frontal seal, consisting of an axially polarized permanent magnet, two L-shaped pole pieces and a ferromagnetic liquid which is held by a magnetic field in the gaps between the pole pieces and the flange faces on the shaft.

The essence of the seal according to the invention, comprising a permanent magnet, pole shoes placed in the housing and a ferromagnetic liquid filling the gaps between the pole shoes and the flange faces on the shaft, is that the seal holder is slidably mounted in the housing seat. Permanent magnets are radially polarized and are arranged with pole shoes on both sides of the collar. Moreover, in the seal housing there are slip rings, the faces of which are in contact with the faces of the flange. Preferably, the seal housing is connected to the seal housing by means of flexible bellows or is slidably mounted therein and sealed to it by an "O" ring.

An advantage of the seal according to the invention is the possibility of allowing a greater radial runout of the shaft compared to a conventional ferromagnetic fluid seal design. Moreover, the use of a bellows or an "O" type seal ensures that the seal is insensitive to flange shape deviations.

The subject of the invention is illustrated in the embodiment in the drawing, in which fig. 1 shows a cross-section through a sealing with the use of flexible bellows, and fig. 2 - a cross-section using a sliding connection of the housing with the housing.

A seal housing 3 is mounted on the shaft 1 provided with a flange 2, which is made of a material with good magnetic permeability. In the housing seat 3, around the flange 2 there is a two-piece seal housing 4 made of a diamagnetic material. Inside this mount, permanent magnets 6 polarized radially are placed between the pole pieces 5 on both sides of the flange 2 end faces. In the housing 4, on both sides of the flange 2, slip rings 7 are also embedded, the faces of which make contact with the faces of the flange 2. The task of the slip rings 7 is to maintain a certain distance between the flange 5 and the faces of the flange 2 and thus create a gap which is filled with ferromagnetic fluid 8. The seal holder 4 is preferably connected to the housing 3 by flexible bellows 9 arranged on both sides of the housing 4, or the housing 4 is preferably slidably seated in the housing seat 3 and is then sealed against it by a ring type "O" 10. In the case of using the bellows 9, which ensure a sliding position of the housing 4 in relation to the flange 2, they additionally protect the housing 4 against rotation in relation to the shaft 1. If a sliding connection of the housing 4 with the housing 3 is used, such a connection also ensures a sliding positioning of the housing 4 in relation to the flange 2.

During the operation of the seal according to the invention, the ferromagnetic liquid 8, located in the gaps between the pole pieces 5 and the faces of the flange 2 on both sides thereof, is held in them by the magnetic field forces generated by permanent magnets 6, thus ensuring the tightness of the system.

10 δ

Fg. 2

183 050

Department

Publishing houses

Price 2.00 AEdition 50 eg ²

Claims (3)

Patent claims 1. A face seal with a ferromagnetic liquid containing a permanent magnet, pole pieces placed in the housing and a ferromagnetic liquid filling the gaps between the pole pieces and the faces of the flange on the shaft, characterized by the fact that in the housing seat (3) a seal holder (2) is slidably positioned against the flange (2) ( 4), and the permanent magnets (6) are radially polarized and are arranged with the pole pieces (5) on both sides of the flange (2), and in the seal housing (4) there are slip rings (7), the front surfaces of which touch with the faces of the flange (2) on both sides. 2. A seal according to claim A device as claimed in claim 1, characterized in that the seal housing (4) is connected to the housing (3) by flexible bellows (9). 3. A seal according to claim The housing of claim 1, characterized in that the seal housing (4) is slidably mounted in the housing (3) and is sealed to the housing (3) by an O-ring (10).