Dynamic and static pressure composite gas bearing with internal pi shaped air wedge groove

Abstract

The invention provides a dynamic and static pressure composite gas bearing with an internal pi shaped air wedge groove, which relates to bearing technology, and belongs to a gas bearing with a novel structural form for supporting an ultrahigh speed rotary machine. The gas bearing is structurally characterized in that the inner surface of the bearing adopts pi shaped air wedge groove design, dynamic and static pressure composite design, and dynamic and static pressure design of a thrust surface; the thrust surface adopts spiral pressurizing groove design; and the inner surface and the thrust surface are provided with a static pressure gas supply hole respectively. The gas bearing overcomes the defects of the coupling and mutual interference between static pressure and dynamic pressure, overcomes the defect that the dynamic pressure effects at two ends of the bearing are inconsistent, not only remarkably improves the bearing capacity and rotating speed of the bearing, but also greatly reduces the axial and transverse vibration of a rotor journal, and improves the stability and reliability of a rotor system. Therefore, the gas bearing has the advantages of simple structure, high bearing capacity, stable operation and high reliability, and further widens the application range of the gas bearing.

Description

technical field [0001] The invention belongs to the technical field of bearings, and relates to an inner π-shaped air wedge groove dynamic and static pressure composite air bearing for supporting high-speed rotating machines. Background technique [0002] Air bearing is a high-tech product developed rapidly in the middle of the 20th century. Compared with traditional rolling bearings or oily sliding bearings, it has high speed, high precision, low power consumption, no pollution, long life, and environmental adaptability. Strong and other advantages. Therefore, it is widely used in national defense, energy, machine tools and medical industries, especially in the fields of ultra-high-speed rotating machinery and ultra-precision instrument technology. [0003] At present, there are two basic lubrication methods for air bearings, one is hydrostatic air bearings, such as figure 1 shown; the other is a dynamic pressure air bearing or a dynamic and static pressure hybrid air bea...

AI Technical Summary

Problems solved by technology

There are two main problems: one is that the air supply nozzle 6 of the static pressure system is located in the pressurized channel groove 3 of the dynamic pressure system. When the air supply of the static pressure system is uneven or the rotor vibrates, the air supply nozzle 6 comes in The flow field formed by the air is disturbed, and the support stiffness at both ends of the bearing is no longer equal, which will cause excessive vibration or instability of the high-speed rotating machinery; the second is that the two pressurized flow channel grooves at both ends of the bearing of the dynamic pressure system are not connected, and in the rotor In the case of vibration or unequal static air supply pressure, the dynamic pressure effect at both ends of the bearing is no longer equal, thereby reducing the bearing capacity of the air bearing, that is, reducing the reliability of high-speed rotating machinery

[0006] Patent application: Dynamic pressure air bearing with inner channel self-lubricating structure, application number: 200720177829.4, see Figure 5A , Figure 5B As shown, its main content is as follows: it is composed of rotor journal 1, bearing body 2, pressurized flow channel groove 3, and elastic ring 4; there are two main problems: one is that because it is a pure dynamic pressure air bearing, the stage and low-speed stage (such as below 20,000 rpm), the dynamic pressure effect of the air bearing is poor, the journal cannot be effectively floated, and the bearing is not well lubricated, resulting in serious short-term rubbing and vibration; the second is that the bearing The two pressurized runner grooves at both ends are not connected. Under the vibration of the rotor or local friction or external disturbance, the dynamic pressure effect at both ends of the bearing is no longer equal, thereby reducing the bearing capacity of the dynamic pressure air bearing, that is, reducing Reliability of high-speed rotating machinery

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