RU167797U1 - Labyrinth seal - Google Patents

Abstract

The invention relates to a sealing technique and can be used in machines for various purposes to seal radial gaps between rotating and stationary nodes. The technical result is achieved by the fact that in a labyrinth seal containing a seal housing mounted in the stator and mating with the rotor on the radial inner surface of which consecutively made annular grooves forming sealing scallops, wherein the annular groove is made in a zigzag shape, while the end along erhnosti ridges are parallel to each other and relative to the radial inner surface of the seal housing disposed at an angle of 60 to 90 gradusov.Izobretenie provides high efficiency due to small leaks through the seal and maintaining sealing performance by increasing the radial clearance during operation.

Description

The invention relates to a sealing technique and can be used in machines for various purposes for sealing radial gaps between rotating and fixed nodes.

The closest analogue to the claimed invention is a labyrinth seal containing a seal housing installed in the stator and mating with the rotor, on the radial inner surface of which are annular grooves forming sealing ridges, the inner edges of which form a labyrinth gap with the rotor (V. B. Shnepp The design and calculation of centrifugal compressor machines. - M .: Mechanical Engineering, 1995. - p. 131), which is taken as a prototype.

The disadvantage of this design is that when working as a result of swirling the gas flow in the seal in the presence of an eccentricity of the rotor, the force effect on the rotor surface from the arising circulation forces sharply increases.

As a result of the force action, resonance phenomena can occur at the natural frequency of the rotor, which can lead to vibrations with an amplitude exceeding the clearances in the bearings, which leads to wear of the ridges of the labyrinths and often to destruction of equipment.

The forces increase significantly with the wear of the scallops, an increase in the radial clearance and misalignment of the rotor and stator parts, which leads to an increase in leakage flow, thereby reducing the efficiency of the seal and an increase in the radial and axial forces acting on the rotor.

The objective of the invention is to increase the efficiency of the seal in terms of reducing radial dynamic effects on the rotor with increasing radial clearance and the presence of misalignment of the rotor and stator part of the seal.

The technical result consists in eliminating vortex formations between the scallops in the seal grooves due to the shape of the scallops and grooves of the claimed invention and in reducing the circulating forces acting on the rotor, which makes it possible to increase the efficiency of the labyrinth seal with increasing clearance and misalignment of the rotor and stator parts of the seal.

The specified technical result is achieved by the fact that in the known labyrinth seal containing the seal housing mounted in the stator and mating with the rotor, on the radial inner surface of which there are successively made annular grooves forming sealing ridges, wherein the annular groove is made in a zigzag shape, while the end surfaces scallops are parallel to each other, and with respect to the radial inner surface of the seal body are located at an angle of 60 to 90 degrees.

Thanks to the introduction of zigzag scallops into a known object, located at an angle to the radial inner surface of the housing from 60 to 90 degrees, the labyrinth seal provides:

- the absence of vortex formations between the combs, which lead to the appearance of circulating forces in the seal, which provides dynamic stability of the rotor, especially in equipment operating under high pressure;

- reducing the swirling flow at the entrance to the labyrinth seal due to the presence of protruding scallops in the flow. Scallops serve as guiding elements dissecting the rotating flow and guiding it into the seal along the axis;

- increased rigidity of the combs of the seal and, as a consequence, the ability to use with large pressure drops.

In FIG. 1 shows a labyrinth seal of a machine in section.

In FIG. 2 shows a view A from figure 1 of this seal.

The labyrinth seal contains a rotor part 1 and a seal housing (stator) 2, between which there is a gap δ. The housing 2 is made in the form of a ring, on the inner surface of which there are combs 3, each comb of the part is parallel to each other, and to the radial inner surface of the housing 2 at an angle α. The angle α is 60-90 degrees. In this case, the scallops form annular grooves 4 of a zigzag shape. The number of scallops depends on the design of the assembly and the working conditions of the labyrinth seal.

Such labyrinth seals are manufactured using selective laser fusion technology, for example, at a Concept Laser M2 installation.

The inventive device operates as follows. In the seal, when the medium flows through the radial clearance δ between the combs 3 of the housing 2 and the rotor 1 due to the pressure drop, the medium is throttled in the gaps between the sealing combs and the rotor surface. The zigzag shape of the annular grooves divides the fluid flow at the inlet of the seal into separate jets, and also prevents the formation of vortex phenomena in the annular grooves between the combs, contributing to the appearance of circulating forces on the rotor.

Thus, the invention provides high sealing efficiency and reduces circulation forces, thereby reducing the force on the rotor with increasing radial clearance during operation.

Claims (1)

A labyrinth seal comprising a seal housing mounted in a stator and mating with a rotor, on the radial inner surface of which are annular grooves forming sealing ridges, characterized in that the annular groove is made in a zigzag shape, while the end surfaces of the ridges are parallel to each other, and relative to the radial inner surface of the housing, the seals are located at an angle of 60 ° to 90 °.

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