Axial force balancing structure of centrifugal closed impeller

Abstract

An axial force balancing structure of a centrifugal closed impeller comprises a sealing ring which is arranged between an impeller cover and a housing and near the outlet of the centrifugal closed impeller, an impeller inlet seal arranged near the inlet of the centrifugal closed impeller, and a housing inlet formed in the housing, wherein the impeller cover, the housing, the sealing ring and the impeller inlet seal form a cavity; a high pressure medium is introduced into the cavity from the outside through the housing inlet; the pressure of the high pressure medium is higher than the medium pressure at the outlet of the centrifugal closed impeller. The axial force balancing structure can balance an existing axial force from an impeller disc to the impeller cover of the centrifugal closed impeller; the axial force balancing structure does not affect flowing of the medium inside the centrifugal closed impeller, so that the efficiency of an impeller is not affected; the axial force balancing structure does not increase the axial length; the high pressure medium can be from the medium at an outlet of a pressure expander behind the centrifugal closed impeller, so that a risk of medium leakage is avoided; the axial force balancing structure is simple in structure and easy to implement.

Description

technical field [0001] The invention relates to the technical field of impeller mechanical engineering, in particular to an axial force balance structure of a centrifugal closed impeller. Background technique [0002] For centrifugal pumps, fans and compressors, due to the different fluid forces on the outside of the impeller disc and the wheel cover, there is still a part of the axial force after canceling each other. This part of the axial force acts on the impeller, and because the impeller Arranged on the shaft, so that the axial force also acts on the rotor, and its direction of action is from the high pressure end to the low pressure end. It is necessary to try to balance or eliminate the axial force on the rotor, otherwise it will cause the rotor to move and even contact the fixed parts, causing damage to the parts. In most cases, it is not enough to rely on the thrust bearing alone, and a hydraulic / pneumatic balancing method is required to balance part of the axial ...

AI Technical Summary

Problems solved by technology

For example, the disadvantage of setting the balance hole is that it will affect the flow at the inlet of the impeller and reduce the efficiency of the impeller. It is not suitable for occasions with high impeller performance requirements; Complicated, not suitable for occasions with long shafts; the disadvantages of setting the balance plate are: 1) the length of the shaft is increased; 2) it is dangerous to the medium, and the space between the impeller disc and the partition or casing behind the disc is limited, For example, the main helium fan of a high-temperature gas-cooled reactor, the balance disc and the impeller will be in two environments, and there will be a danger of medium leakage when the medium is introduced from the impeller inlet to the balance disc side

Therefore, the use of the balance plate is also limited.

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