SU1265429A1 - Magnetic liquid sealing - Google Patents

Abstract

The invention relates to a sealing technique and can be used to seal the shafts of machines and apparatus. The aim of the invention is to increase the reliability of the seal by creating a gap between the non-magnetic sleeve and the anti-friction gasket of the support ring and 1C1 circulation through it of the sealing medium. Before turning on the drive of rotation of the shaft 5, the sealing medium is supplied under pressure. By adjusting the pressure of the barrier medium and due to the possibility of axial movement of the magnet assembly, an optimum clearance 11 is established. By creating a fluid friction between the non-magnetic sleeve 10 and the anti-friction gasket 4, the barrier medium also unloads the stages of a magnetic seal 7 consisting of a pole magnet 7 with pole pieces 8 , 9, and magnetic fluid in sealed gaps, formed by pole tips 8, 9 and support ring 3, and contributes to the cooling of the magnetic liquid-liquidity. shadows. In emergency mode, the non-magnetic sleeve 10 is in contact with the anti-friction gasket 4, since the coefficient of temperature expansion of the material of the latter is greater than the coefficient of temperature expansion of the material of the support ring 3. 1 Cp f-ly, 1 ill.

Description

(54) MAGNET-WATERPROOF SEAL (57) The invention relates to a sealing technique and can be used to seal shafts of machines and apparatuses. The aim of the invention is to increase the reliability of the seal by creating a gap between the non-magnetic sleeve and the antifriction gasket of the support ring and the circulation of the gate medium through it. Before turning on the shaft rotation drive 5, a gate medium is supplied under pressure to the gap 11. By controlling the pressure of the gate medium and due to the possibility of axial movement of the magnetic assembly, the optimal eazor 11 is established. By creating fluid friction conditions between the non-magnetic sleeve 10 and the antifriction gasket 4, the gate medium also unloads the stages of the magneto-liquid seal, consisting of a permanent magnet 7 with pole tips 8, 9 and a magnetic fluid sealing gaps formed by the pole pieces 8, 9 and the support ring 3, and promotes the cooling of the seal _with magnitozhidkostno- . In emergency mode, the non-magnetic sleeve 10 is in contact with the anti-friction gasket 4, because the coefficient of thermal expansion of the material of the latter is greater than the coefficient of thermal expansion of the material of the support ring 3. 1 z.p. f-ly, 1 ill.

SU. 1265429 A1

The invention relates to a sealing technique and can be used to seal shafts of machines and apparatuses.

The purpose of the invention is to increase the reliability of the seal by creating a gap between the non-magnetic sleeve and the antifriction gasket of the support ring and the circulation of the gate medium through it.

The drawing shows a magnetic fluid seal, section.

In the non-magnetic housing 1, a support ring 3 is installed through an elastic sealing ring 2, which is a magnetic circuit and is made of soft magnetic material with a non-magnetic antifriction gasket 4 installed in it.

On the shaft 5, a magnetic assembly with axial movement is mounted on the key 6, consisting of a permanent annular magnet 7 and pole pieces 8 and 9. A separating non-magnetic sleeve 10 is installed between the pole pieces 8 and 9, which forms a gap 11 with a non-magnetic anti-friction gasket 4.

The gap 11 is communicated by channels 12 and 13 with a source of pressure of the gate medium. Channels 12 and 13 are made in fixed parts. On the end surfaces of the pole pieces 8 and 9, forming a working gap with a support ring 3 to create an uneven magnetic field, annular grooves 14 are filled with ferromagnetic fluid. The magnetic assembly is sealed relative to the shaft 5 by an elastic sealing ring 15 installed in the groove made on the inner radial surface of the pole piece.

Sealing works as follows.

Before turning on the drive of rotation of the shaft 5 from the pressure source of the gate medium through the underwater channel 12, the medium is supplied under pressure to the gap 11. By adjusting the pressure (or flow) of the gate medium, the optimal working gap is established by moving the magnetic VNIIIPI Order 5644/29

Custom polygr.

th node on the shaft 5. The shutter medium is discharged through the channel 13. After the optimal clearance is established, the shaft rotation drive is turned on 5. The magnetic flux generated by the permanent ring magnet 7, closing through the pole pieces 8 · and 9 and the support ring 3, creates an airtight plug between them from magnetic fluid. Under the influence of the pressure drop, the ferromagnetic fluid is pushed out of the working gap, however, under the influence of magnetic forces proportional to the gradient of the magnetic field, it is held in the working gap, thus ensuring the sealing of the rotating shaft. Creating the conditions of fluid friction between the non-magnetic sleeve 10 and the antifriction gasket 4, the gate medium also destroys the stages of the magneto-liquid seal and contributes to its cooling.

Claims (1)

Formula & W Retention 1. A magneto-liquid seal containing a magnetic assembly, mounted axially movable, made in the form of a permanent magnet with pole tips and magnetic fluid in the sealing gaps, as well as a support ferromagnetic ring with antifriction gasket on the end surface from the side of the magnetic assembly characterized in that, in order to increase the reliability of the seal, it is equipped with a dividing sleeve of 40 non-magnetic material installed between the pole pieces and the pressure source the gate protection, and anti-friction gasket is installed on the front surface of the support ring 45 is flush with it to form the dividing gap sleeve, channels which communicates with a source of fluid pressure bolt. 50 2. The seal according to claim 1, characterized in that the antifriction gasket is made of a material with a greater coefficient of thermal expansion than the material 55 of the support ring.