RU1802226C - Combination bearing assembly - Google Patents

Abstract

(Usage: bearings of high-precision spindle assemblies. Summary of the invention: a bearing assembly comprises a housing with a shaft located therein. A rolling bearing and a sliding bearing are mounted on the shaft, in which there is a working medium in the gap between the supporting surfaces. The plain bearing is magnetically liquid in the form rigidly mounted in the housing of the annular liner with two conical surfaces and rigidly fixed to the shaft of the annular permanent magnet with the annular enveloping it at the ends The magnetic cores are made with conical surfaces facing each other and cover the conical surfaces of the annular liner with a gap. Magnetic fluid was used as the working medium, and the assembly design increases the accuracy of shaft rotation by reducing vibrations. 3 ill. with C

Description

The invention relates to mechanical engineering and can be used as supports for precision spindle assemblies for various purposes.

An object of the invention is to increase the accuracy of shaft rotation in both the radial and axial directions by reducing the vibrations arising from the rotation of the shaft. In addition, the proposed technical solution eliminates the following disadvantages: it ensures the operation of the assembly without supplying the working medium to the support elements from the source of overpressure and provides sealing of the movable elements operating under differential pressure conditions.

In FIG. 1 shows a General view of the combined bearing unit, a longitudinal section; in FIG. 2 - section aa; in FIG. 3 section BB of the node.

The combined bearing assembly (Fig. 1) comprises a housing 1 in which an annular liner 2 with two conical surfaces 3 is mounted, and a rolling bearing 5 and a sliding bearing 6 including an annular permanent magnet 7, ring magnetic circuits 8 are fixed to the shaft 4. and 9 with conical surfaces 10 on which are applied as shown in FIG. 2 and 3, spiral grooves 11, 12, and the gaps between the conical surfaces 3 and 10 are filled with magnetic fluid 13.

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The node operates as follows.

When the shaft 4 is accelerated from zero to the nominal speed, the initial main bearing of the shaft is the rolling bearing 5. Further, as the speed of rotation of the shaft 4 increases, the interaction of the conical surfaces 10 of the ring magnetic circuits 8 and 9 with the conical surfaces 3 of the annular liner 2, create. by means of spiral micro-grooves 11. and 12, a hydrodynamic support due to the movement of the magnetic fluid 13 along the conical surfaces 3 and 10 from the periphery to the center, while the plain bearing becomes the main support, so that the magnetic fluid 13 does not splash due to centrifugal forces between the magnetic circuits 8 and 9, an annular permanent magnet 7 is installed, which creates magnetic fields in the working gaps filled with magnetic fluid 13, while ensuring its retention.

As the shaft speed decreases, the force of the hydrodynamic support of the sliding bearing 6 decreases, and the assembly acts as a rolling bearing.

Reducing the vibration of the assembly and increasing the accuracy of rotation of the shaft is achieved by creating a radial and axial hydrodynamic support, the rigidity of which increases with increasing frequency of rotation of the shaft, while eliminating the need for

the necessity of supplying the working medium under pressure to the sliding bearing and provides sealing of the movable elements of the assembly during operation under differential pressure conditions.

Claims (1)

SUMMARY OF THE INVENTION A combined bearing assembly comprising a housing with a shaft disposed therein and sequentially mounted on the last rolling bearing and a sliding bearing, in which there is a working medium in the gap between the supporting surfaces, characterized in that, in order to increase the accuracy of shaft rotation by to reduce vibrations, the plain bearing is magnetically liquid in the form of an annular liner rigidly mounted in the housing with two conical surfaces and a ring rigidly fixed to the shaft a permanent magnet with ring magnetic circuits enclosing it at the ends, made with conical surfaces facing one another and covering conical surfaces of the annular liner with a gap, moreover, on the working conical surfaces of the magnetic circuits, helical microgrooves are uniformly made towards one another along the shaft rotation from the peripheral surface of the cone to the center of the shaft, and magnetic fluid was used as the working medium. 0 5 0 + fi $ 2