High-speed hydrodynamic machine and composition method and assembly method of rotor of high-speed hydrodynamic machine

Abstract

The invention relates to a high-speed hydrodynamic machine of which the rotating speed is above 6000rpm, particularly between 7000rpm and 20000rpm. The high-speed hydrodynamic machine comprises a driving motor and a rotor, wherein the rotor comprises a driving motor rotating shaft and rotating impellers acting on fluid; and the rotating impeller are directly mounted on the driving motor rotating shaft, connected in a keyless manner, positioned together with the driving motor rotating shaft in an interference manner through hot-pressing in a radial direction, and compressed and pushes against a radial flange of the rotating shaft by a locking structure in an axial direction. In addition, the invention further relates to a composition method and an assembly method of the rotor of the high-speed hydrodynamic machine with the rotating speed above 6000rpm. According to the machine, since the rotating impellers are directly mounted on the driving motor rotating shaft, the transmission efficiency is improved greatly, the rotor is simpler to dismount simultaneously, and the impellers and the rotating shaft are good in coaxiality and sealability, and low in vibration.

Description

technical field [0001] The invention relates to a rotor of a high-speed fluid power machine, especially a rotor of a high-speed fluid power machine with a speed above 6000 rpm (such as a high-speed centrifugal compressor with a speed above 10000 rpm), and also relates to an assembly method of the rotor . Background technique [0002] At present, high-speed fluid power machinery, especially high-speed centrifugal compressors in the field of air conditioning, mostly increase the speed to the design speed through the speed-increasing gear, and drive the impeller to rotate to do work on the incoming gas, thereby increasing the gas pressure. This conventional compressor structure has the following deficiencies: (1) Due to the intermediate gear speed increase box, the mechanical loss of the compressor is increased, thereby increasing the power consumption of the compressor and affecting the performance of the unit; (2) the existence of the gear box The shape and structure of the ...

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Problems solved by technology

This conventional compressor structure has the following deficiencies: (1) Due to the intermediate gear speed increase box, the mechanical loss of the compressor is increased, thereby increasing the power consumption of the compressor and affecting the performance of the unit; (2) the existence of the gear box The shape and structure of the compressor are greatly increased, making the box appear bulky and heavy, and the cost also increases; (3) Due to the high speed of the centrifugal compressor, the noise during the gear speed-up process is very loud, so the noise of conventional centrifuges is common It is about 93 decibels, which makes it necessary to add additional sound insulation measures in engineering applications, resulting in increased engineering costs; (4) The motor used in conventional centrifugal compressors is a three-phase asynchronous motor, and the highest motor efficiency is about 94%. It is very difficult to further improve energy efficiency; (5) The frequency conversion of conventional centrifugal compressors belongs to the category of low-speed frequency conversion, that is, adding a frequency converter to an ordinary three-phase asynchronous motor, although this method can increase part of the load compared with the fixed frequency method. performance, but due to the existence of the gear transmission mechanism, mechanical transmission loss is caused, especially at partial load, so the room for improvement of partial load performance is also restricted

[0007] In the prior art, in view of the convenience of disassembly and assembly, the impeller and the rotating shaft are mostly connected by keys, and the surface quality of the key connection surface is required to be high. At the same time, the force is uneven during work, and stress concentration is prone to occur. Through experiments, we found that For high-speed fluid power machinery with a rotating speed above 10,000rpm, the force is mainly concentrated at the root of the key and the root of the keyway, which reduces the load-carrying capacity of the impeller, causing the impeller to be prone to fatigue failure during operation, unable to withstand impact loads, and keys are often corroded, broken, Keyway deformation and key rolling phenomenon, resulting in eccentricity between the impeller and the shaft, increased additional unbalance, etc., seriously affecting the performance of high-speed fluid power machinery, this phenomenon is especially high-speed centrifugal compression with a speed above 10,000rpm more serious on board

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