CN104454992B - Elastic radial air bearing - Google Patents

Abstract

The invention discloses a radial elastic air bearing, comprising: a bearing body, a wire mesh ring and a flexible tilting pad structure, the bearing body and the wire mesh ring are coaxially arranged, and two wire meshes of the same specification The mesh ring is symmetrically installed in the annular grooves at both ends of the bearing body. The flexible tilting pad structure is mainly composed of a bearing pad and a flexible supporting structure. The bearing pad is arranged inside the bearing body. The bearing pad is connected to the bearing body through a flexible supporting structure connected, the inner surface of the bearing bush forms the mating surface of the bearing and the rotating shaft. The invention adopts the form of flexible tilting pad structure and wire mesh ring arranged in parallel, so that the bearing has the characteristics of high rigidity and high damping at the same time, which improves the bearing capacity of the bearing, reduces the vibration impact of the bearing, and improves the bearing performance at the same time. Reliability and operational stability.

Description

A Radial Elastic Air Bearing

technical field

The invention relates to the technical field of air bearings, in particular to a radial elastic air bearing.

Background technique

The air bearing is a self-acting elastically supported air bearing with the air in the surrounding environment as the lubricant. Air bearings greatly reduce the friction between the drive shaft and bearings by forming a thin film of air between the drive shaft and the bearings. Compared with ordinary rotor bearings, it has a series of advantages such as high speed, good precision, high reliability, no oil lubrication, small friction loss, and can work in high temperature environment.

In the field of air bearings, the elastic support structure plays the role of support and vibration reduction. The elastic support structure is adopted, and the working air film gap of different thickness can be established at any time according to the different loads. In the air bearing, the elastic support structure should have good stiffness and damping at the same time, so that the bearing can obtain a good load-bearing capacity and the ability to cushion shock vibration. The elastic support structure with excellent performance can use its damping characteristics to well suppress the vibration of the rotor, greatly increasing the reliability and operation stability of the bearing.

After decades of development, air bearings have greatly improved their load-carrying and vibration-damping capabilities, but the new air bearings only simply change the parameters of the wave foil on the basis of the predecessors, and fail to improve the performance of the bearings. Substantial improvements have been made in the structure, and the damping characteristics of the bearing need to be further improved. Therefore, how to improve the performance of the elastic support structure to improve the performance of the air bearing has become a very important issue.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art, and provide a kind of by improving the elastic support structure of the air bearing, improve the damping and rigidity of the support structure, reduce the impact caused by vibration, improve the overall bearing capacity and operation stability of the bearing Radial elastic air bearings.

In order to achieve the above object, the present invention adopts the following technical solutions: a radial elastic air bearing, comprising: a bearing body, a wire mesh ring and a flexible tilting pad structure, the bearing body and the wire mesh ring are arranged coaxially, Two wire mesh rings of the same specification are symmetrically installed in the annular grooves at both ends of the bearing body. The flexible tilting pad structure is mainly composed of a bearing pad and a flexible supporting structure. The bearing pad is arranged inside the bearing body. The bearing pad The flexible supporting structure is connected with the bearing body, and the inner surface of the bearing pad forms a matching surface between the bearing and the rotating shaft.

Further, the flexible tilting pad structure and the bearing body adopt an integral structure.

Further, the bearing pads are evenly distributed in the circumferential direction, and the surface of the bearing pads in contact with the rotating shaft is provided with a coating.

Further, the bearing bush can rotate at a small angle.

Further, the wire mesh ring is first woven into a mesh shape by metal wires of specified quality, and then made into a desired ring shape by a cold stamping process.

Further, the wire mesh ring is set as a hollow cylindrical structure.

Further, an air supply channel and an orifice are provided in the flexible supporting structure, and an air cavity is provided on the bearing bush.

Further, the air cavity is an asymmetric structure.

The technical scheme adopted in the present invention has the following beneficial effects:

The invention adopts the form of flexible tilting pad structure and wire mesh ring arranged in parallel, so that the bearing has the characteristics of high rigidity and high damping at the same time, which improves the bearing capacity of the bearing, reduces the vibration impact of the bearing, and improves the bearing performance at the same time. reliability. When the bearing works normally, a wedge-shaped air film will be formed on the mating surface of each bearing pad and shaft, which greatly improves the running stability of the bearing. At the same time, the bearing pad on the bearing body will rotate and move radially under the action of the air film pressure, and the flexible tilting pad structure will be deformed. At this time, the bearing pad will press the wire mesh ring to deform it, thereby providing a Elastic support. The flexible tilting tile structure has the characteristics of high stiffness and small damping, while the wire mesh ring has the properties of large damping and low stiffness. Under the joint action of the flexible tilting tile structure and the wire mesh ring, the stiffness characteristics of the two The damping characteristics are superimposed on each other, and the air bearing has the characteristics of high stiffness and high damping at the same time.

Compared with the existing air bearings, the elastic composite support structure proposed by the present invention improves the bearing damping and stiffness characteristics, significantly improves the bearing capacity of the bearing and the ability to moderate shock vibration, and also improves the reliability of the gas bearing to a certain extent. question.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the radial elastic air bearing of the present invention;

Fig. 2 is a schematic structural view of a bearing body provided in the first embodiment of the present invention;

Fig. 3 is a schematic diagram of a partial structure of a bearing body provided in the first embodiment of the present invention;

Fig. 4 is the structural representation of the wire mesh ring of the radial elastic air bearing of the present invention;

Fig. 5 is a schematic structural view of another bearing body provided in the second embodiment of the present invention;

Fig. 6 is a partial structural schematic diagram of another bearing body provided in the second embodiment of the present invention;

Fig. 7 is a schematic diagram of cooperation between the bearing body and the wire mesh ring of the present invention;

In the figure: 1. Wire mesh ring, 2. Bearing body, 3. Bearing bush, 4. Flexible support structure, 5. Air supply channel, 6. Throttle hole, 7. Air cavity.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. However, it can be understood that the following specific embodiments are only preferred technical solutions of the present invention, and should not be construed as limiting the present invention.

Embodiment one

As shown in Figure 1, a radial elastic air bearing includes: a bearing body 2, a wire mesh ring 1 and a flexible tilting pad structure, the bearing body 2 and the wire mesh ring 1 are arranged coaxially, and are composed of two Two wire mesh rings 1 of the same specification are symmetrically installed in the annular grooves at both ends of the bearing body 2. The flexible tilting pad structure is mainly composed of a bearing pad 3 and a flexible supporting structure 4. The bearing pad 3 is arranged inside the bearing body 2. , the bearing pad 3 is connected to the bearing body 2 through a flexible support structure 4, when the bearing pad 3 is subjected to a radial force, the bearing pad 3 will press the flexible supporting structure 4, thereby causing the bearing pad 3 to move radially, and the inner surface of the bearing pad 3 forms a The mating surface of the bearing and the shaft. Inside the bearing, the elastic support structure is composed of a flexible tilting pad structure and a wire mesh ring.

As shown in Figure 2, the bearing body 2 is the main structure of the bearing, which plays the role of installation, protection and support. The two ends of the bearing body 2 have annular grooves, and the inner surface of the bearing body 2 is processed with n The bearing bush 3, the surface of the bearing bush 3 is the mating surface of the bearing and the rotating shaft, and is preferably coated. Figure 3 is a partial schematic diagram of the bearing body 2, the bearing bush 3 can be rotated at a small angle according to the rotation of the bearing to adjust the position and angle, so as to improve the running stability of the bearing. The n bearing pads on the bearing body 2 are evenly distributed in the circumferential direction, and the central angle corresponding to the center of every two adjacent bearing pads is θ, then θ=360°/n, the connection between the flexible support structure 4 and the bearing pad 3 The angle corresponding to the corresponding radial line and the horizontal direction is β, which can be changed according to the stress on the bearing pad. Due to the asymmetric distribution of the wedge-shaped air film pressure on the bearing pad 3, the connection often deviates from the bearing pad. The central position of the flexible tilting pad structure and the bearing body 2 adopt an overall structural design, which not only simplifies the structure of the air bearing, but also avoids the influence of the accumulation of assembly errors on the bearing, and improves the precision of the bearing after processing. The flexible support structure 4 also reduces the requirements for machining accuracy, eliminates the problem of wear when the bearing pad 3 and the connecting part of the bearing rotate in the traditional tilting pad bearing, and avoids the traditional tilting pad bearing that causes the bearing pad 3 and The wear between the shafts improves the stability and reliability of the bearings.

As shown in Figure 4, the wire mesh ring 1 is to use a certain method to weave the metal wires according to the quality into a mesh shape, and then use a cold stamping process to make a ring that meets the requirements. By changing the shape of the wire mesh 1 Parameters such as material, relative density, wall thickness and axial length can change its stiffness and damping characteristics. The wire mesh ring 1 is installed on the groove of the bearing body 2, and two wire mesh rings 1 are symmetrically embedded in the bearing body 2. both ends.

When the bearing is working, the composite support structure composed of the flexible tilting pad structure and the wire mesh ring 1 provides elastic support for the bearing together, and the bearing pad 3 will rotate and move radially under the action of the gas film pressure, thus changing the bearing pad 3 and the gap between the shaft is conducive to the formation of wedge-shaped air film. While the bearing pad 3 on the bearing body 2 rotates and moves radially under the action of the air film pressure, the bearing pad also compresses the wire mesh ring to cause deformation at the same time, jointly providing elastic support for the bearing. The flexible tilting tile structure has the characteristics of large rigidity and small damping, while the wire mesh ring 1 has the properties of large damping and small stiffness. Under the joint action of the flexible tilting tile structure and the wire mesh ring 1, the stiffness of the two The characteristics and damping characteristics are superimposed on each other, and the air bearing has the characteristics of high stiffness and high damping at the same time. At the same time, the same kind of air bearings with different damping and stiffness characteristics can also be obtained by changing the axial length of the wire mesh ring 1 and the length of the flexible support structure 4 in the flexible tilting pad structure.

Embodiment two

Fig. 5 is a schematic structural view of another bearing body provided in the second embodiment of the present invention.

The working principle of the bearing in this embodiment is generally the same as that in Embodiment 1, the difference is that this embodiment is a gas-dynamic-static-pressure hybrid bearing. The aerodynamic pressure bearing in the first embodiment cannot form a sufficient gas film separating the two friction surfaces due to the low speed during the start-up and stop-down process, and wear is prone to occur. The gas dynamic and static pressure hybrid bearing is used in the second embodiment, which not only avoids the wear of the gas dynamic pressure bearing in the process of starting and stopping, but also has extremely high rotation accuracy and high load carrying capacity at any speed.

Figure 6 is a partial cross-sectional view of the bearing body in the gas dynamic and static pressure bearing. The difference from the first embodiment is that the flexible support structure in this embodiment is provided with an air supply channel 5 and an orifice 6, and the bearing bush 3 is provided with There is an air chamber 7, and the air chamber 7 adopts an asymmetric structure, which is conducive to the deflection of the bearing bush 3, thereby making it easier to form a wedge-shaped air film, and at the same time helping to improve the pressure distribution on the bearing bush 3. When the bearing is working, the hydrostatic bearing provides gas pressure from an external pump to form a pressure gas film to bear the load. In this way, it is ensured that the two surfaces of the friction pair of the bearing are not in direct contact during the start and stop stages, so as to avoid wear and tear.

While retaining the high damping and high rigidity characteristics of the air bearing, the bearing body structure solves the problem of bearing wear when the shaft rotates at low speed, prolongs the working life of the bearing, and at the same time, because the pressure on the surface of the friction pair is relatively uniform, Improve the reliability and stability of the bearing.

In summary, the present invention adopts the wire mesh ring structure to provide damping for the bearing. The wire mesh ring 1 has certain elasticity and damping characteristics while retaining the metal properties, and at the same time adopts a flexible tilting pad structure to provide rigidity for the bearing. The present invention improves the elastic support structure of the air bearing and uses the superposition effect of the flexible tilting pad structure and the stiffness and damping of the wire mesh ring 1 to improve the bearing capacity of the air bearing and the ability to moderate impact vibration, so that the air bearing has good performance. Rigidity and damping improve bearing capacity and running stability.

In addition to the examples mentioned above, the bearing body and the wire mesh ring can have different installation and fixing methods. The specific shape parameters of the flexible tilting pad structure on the bearing body and the wire mesh ring can be designed according to different situations. The number and distribution of bearing bushes can also be designed according to different situations. The examples cited above are only preferred examples of the present invention, and all simple equivalent changes and modifications made according to the claims of the present invention and the content of the invention should fall within the scope covered by the patent of the present invention.

Claims (9)

1. A radial elastic air bearing, comprising: a bearing body (2), a wire mesh ring (1) and a flexible tiltable pad structure, the bearing body (2) and the wire mesh ring (1) are coaxial The setting is characterized in that two wire mesh rings (1) of the same specification are symmetrically installed in the annular grooves at both ends of the bearing body (2), and the flexible tilting pad structure is mainly composed of the bearing pad (3) and the flexible support Structure (4), the bearing pad (3) is arranged inside the bearing body (2), the bearing pad (3) is connected with the bearing body (2) through a flexible support structure (4), the bearing pad (3) The surface forms the mating surface of the bearing and the rotating shaft. 2. The radial elastic air bearing according to claim 1, characterized in that the flexible tilting pad structure and the bearing body (2) adopt an integral structure. 3. The radial elastic air bearing according to claim 1, characterized in that, the contact surface between the bearing bush (3) and the rotating shaft is provided with a coating. 4. The radial elastic air bearing according to claim 1 or 3, characterized in that the bearing bushes (3) are evenly distributed in the circumferential direction. 5. The radial elastic air bearing according to claim 1, characterized in that, the bearing bush (3) can rotate at a small angle. 6 . The radial elastic air bearing according to claim 1 , characterized in that, the wire mesh ring ( 1 ) is woven into a mesh shape by metal wires, and then made by cold stamping process. 7 . 7. The radial elastic air bearing according to claim 1, characterized in that, the wire mesh ring (1) is configured as a hollow cylindrical structure. 8. The radial elastic air bearing according to claim 1, characterized in that, the flexible support structure (4) is provided with an air supply channel (5) and an orifice (6), and the bearing bush (3) An air chamber (7) is arranged on it. 9. The radial elastic air bearing according to claim 8, characterized in that, the air cavity (7) is arranged in an asymmetric structure.