SU989217A1 - Magnetic liquid sealing - Google Patents

Description

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The invention relates to a sealing technique and can be used to seal rotating shafts when transmitting motion to controlled environments with increased jEiaBjIeHH,

 A magneto-fluidic seal is known, consisting of a permanent magnet mounted on the shaft in the form of a permanent magnet with adjacent tips with poles, the end surfaces of which are covered by the magnetic conductor c. self-aligning poles on the shaft, rolling elements and ferrofluids in the working gaps in the path of the magnetic flux created by the magnet

However, the location of the rolling bodies in the working gaps contributes to the closure of a part of the main flow through them, and this leads to a decrease in the flow through the working gaps and, therefore, to a decrease in the differential pressure held. In addition, the bodies of rolling in the working gaps are affected by the forces of magnetic attraction and overpressure, which causes an increase in the moment of friction on the seal and,

J as a result, an increase in the power consumed by it.

The purpose of the invention is to increase the held pressure drop and decrease the friction torque for compaction.

This goal is achieved by the fact that the rolling bodies are removed from the working clearances and installed in special non-magnetic bushings fixed on the shaft in such a way that the outer

f5, the end surfaces of the self-aligning poles and the inner side surfaces of the non-magnetic bushings are their supports, and a non-magnetic pole is installed in the annular grooves of the poles

20 glass

The drawing shows the structure of the proposed seal.

Claims (1)

The seal includes a housing 1, a magnet assembly mounted on a rotating shaft 2 and consisting of a standing magnet 3 with pole tips 4 and a nonmagnetic ring 5, which serves to secure the magnet between the pole pieces. On shaft 2 there is a magnetic pipe made in the form of self-installing from the poles 6, in the annular recesses of which there is a non-magnetic cup 7. Special non-magnetic bushings 8 are also fixed on the shaft. Rolling bodies 9 are mounted between the field 6 and bushings 8. In order to create an uneven magnetic field, the working gaps at the poles 6 and the pole tips facing them are made / teeth. The working gaps (i c, d and (ji are filled with ferrofluid 10. Permanent magnet 3, pole pieces H, self-aligning poles 6, body 1 and working gaps L da. D% and (f, filled with ferrofluid 10, form a closed magnetic circuit The magnetic force resulting from the interaction of the magnetic liquid ring with a permanent magnet field prevents the liquid from flowing out of the working gaps under the action of a pressure differential both at a stationary and rotating with a shaft. The magnitude of this force depends on the magnetization of the ferrofluid and With this design, radial and axial movement of the shaft during sealing operation is possible. With radial movement, the magnetic unit mounted on the shaft moves together with the shaft, and the self-adjusting poles remain stationary. With axial movement, the entire magnetic system moves relative to the housing. The tightness of the seal in both cases is not compromised. 174 Techno-economic efficiency is that the proposed seal allows moving the rolling bodies out of the working area increases the magnitude of the pressure differential being held 1.3-1.5 times, and installing a non-magnetic cup in the ring undercuts of the poles reduces the magnetic force acting from the magnetic node on the self-adjusting poles, which reduces the frictional moment in the sealing zone. Claim 1. Magnetic-liquid seal containing a fixed magnet assembly in the form of a permanent magnet with pole pieces, the end surfaces of which are covered by a magnetic circuit in the form of self-aligning poles with annular recesses, gaps between the magnetic assembly and the magnetic circuit, filled with ferrofluid, and the body Rolling, about tl and which is so that, with the purpose of increase of the kept pressure difference and reduction of the moment of training. the seal is provided with non-magnetic bushings mounted on a rotating shaft under self-aligning poles, and the rolling bodies are located between said bushings and strips. 2, the seal according to claim 1, characterized in that, in order to reduce the magnetic attraction forces acting on the self-aligning poles, a non-magnetic cup is installed in the annular recesses of the latter. Sources of information taken into account in examination 1, USSR Author's Certificate for Application No. 2701022 / 25-08. cl. F 16 J, 1978. S: