A dynamic pressure air bearing with axial air intake

Abstract

The present invention discloses a dynamic pressure air-floating bearing with axial air intake, comprising an outer ring and an inner ring which are fitted together, graphite is embedded in the outer ring, there is an inner-outer ring gap of 5-10 μm between the inner ring and the outer ring along the axial direction, the inner-outer ring gap is provided with an inner-outer ring gap inlet and an inner-outer ring gap outlet, the inner-outer ring end faces of the inner-outer ring gap inlet are provided with a chamfer for drainage, and both the outer ring and the inner ring can rotate in coordination with the rotor, a first air intake channel and a second air intake channel are provided on the inner ring, when working, the external air flow enters the inner-outer ring gap through the axial air intake mode, and at the same time, the first air intake channel and the second air intake channel continuously replenish air to the inner-outer ring gap, thereby improving the bearing capacity and stability of the dynamic pressure air-floating bearing. The present invention can realize the rotation of the inner and outer rings and the axial air replenishment, improve the radial bearing capacity and stability, and has a wide range of applications, especially in the field of gas turbine engines.

Description

Technical Field

[0001] The invention relates to the technical field of air floating bearings, and in particular to a dynamic pressure air floating bearing with axial air intake. Background Art

[0002] Air bearings have the advantages of high speed, high precision, and low friction, and are widely used in high-speed precision rotating machinery. Air bearings use air as a lubricant. When working normally, an air film is formed between the bearing and the rotor. The rotor is supported by the air film, and high-speed operation without contact between the bearing and the rotor is achieved. According to the formation mechanism of the load-bearing air film, air bearings can be divided into dynamic pressure air bearings and static pressure air bearings. Among them, static pressure air bearings require an external air source. The gas forms a static pressure air film that supports the load in the gap between the bearing and the rotor. It is frictionless throughout the process and is suitable for high-precision detection. Dynamic pressure air bearings have a simple structure and do not require an air compressor for air supply. After reaching a certain speed, air film lubrication can be formed by itself.

[0003] In recent years, with the continuous advancement of technology, hydrodynamic air bearings have been widely used in industries such as generators, micro gas turbines, compressors, and blowers due to their advantages of high speed, simple structure, design space saving, and low overall cost. However, existing hydrodynamic air bearings can only realize the rotation of the inner ring rotor, and have low load-bearing capacity, poor stability, and certain limitations. In response to the above problems, patents with announcement numbers CN112160981A and others disclose an axial bearing rotor with multiple air supply channels arranged along the circumferential direction. The load-bearing capacity of the axial bearing can be increased without introducing external equipment, but only the rotation of the inner ring rotor can be realized, and the degree of reducing friction at low speeds is limited. Summary of the invention

[0004] The main purpose of the present invention is to provide a dynamic pressure air floating bearing with axial air intake, whose inner and outer rings are both rotatable, and air can be replenished by utilizing the axial air source inside the equipment itself or the rotation of the bearing rotor. The bearing capacity of the bearing can be increased without introducing external equipment, thereby improving the overall stability and having a wider range of applications.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A dynamic pressure air floating bearing with axial air intake comprises an outer ring and an inner ring which are fitted together, graphite is embedded in the outer ring, an inner-outer ring gap of 5-10 μm exists between the inner ring and the outer ring along the axial direction, the inner-outer ring gap is provided with an inner-outer ring gap inlet and an inner-outer ring gap outlet, the inner-outer ring end faces of the inner-outer ring gap inlet are provided with chamfers for drainage, and both the outer ring and the inner ring can rotate in coordination with the rotor, a first air intake channel and a second air intake channel are provided on the inner ring, when working, external air flow enters the inner-outer ring gap through axial air intake, and at the same time, the first air intake channel and the second air intake channel continuously replenish air to the inner-outer ring gap, thereby improving the bearing capacity and stability of the dynamic pressure air floating bearing.

[0007] A further improvement of the present invention is that the bearing is suitable for use in equipment with or without an internal air source. In equipment with an internal air source, compressed air is introduced into the gap between the inner and outer rings, and the first air inlet channel and the second air inlet channel are combined to continuously provide sufficient air for the gap between the inner and outer rings, while cooling the bearing at the same time. In equipment without an air source, the dynamic pressure air floating bearing is used to rotate itself to press air into the gap between the inner and outer rings, while the air intake volume of the gap between the inner and outer rings is increased through the first air inlet channel.

[0008] A further improvement of the present invention is that the outer ring is made of zirconia ceramic material, and graphite having a lubricating effect is evenly embedded in the outer ring, the graphite is evenly distributed in the circumferential direction, and radially penetrates the entire outer ring.

[0009] A further improvement of the present invention is that the first air intake channel is a spiral guide groove, the first air intake channel is evenly distributed along the outer circumferential surface of the inner ring, the inlet of the first air intake channel is located at the inlet of the inner and outer ring gap of the inner ring, and is evenly arranged along the outer circumferential surface of the inner ring, and the first air intake channel adopts a variable cross-section channel, which gradually becomes narrower from wide.

[0010] A further improvement of the present invention is that the second air inlet channel adopts a circular cross-section, the second air inlet channel is extended axially to the middle of the inner ring, and penetrates the inner ring upward to form a second air inlet channel outlet, the second air inlet channel outlet is staggered with the first air inlet channel, and the airflow enters the gap between the inner and outer rings.

[0011] A further improvement of the present invention is that the outlet area of ​​the second air inlet passage is smaller than the inlet area of ​​the second air inlet passage, thereby increasing the outlet flow rate.

[0012] A further improvement of the present invention is that when the first air inlet channel is working in a device with an air source inside a gas turbine or a compressor, the hydrodynamic air bearing uses the high-pressure air generated inside to directly introduce the compressor outlet air source into the inner and outer ring gaps. At this time, the air inlet direction of the first channel is the same as the air outlet direction of the air source; in a device without an air source, the hydrodynamic air bearing presses the gas into the inner and outer ring gaps by its own rotation. At this time, the air inlet direction of the inlet of the first air inlet channel is opposite to the rotation direction.

[0013] A further improvement of the present invention is that the bearing can realize inner and outer ring rotation and axial air replenishment, thereby improving the radial bearing capacity of the hydrodynamic bearing.

[0014] A further improvement of the present invention is that the bearing adopts graphite lubrication and axial air intake, combined with multi-channel air supply, to reduce friction resistance when rotating at low speed, improve wear resistance, and extend the service life of the dynamic pressure air bearing.

[0015] The present invention has at least the following beneficial technical effects:

[0016] 1. The axial air intake hydrodynamic air bearing described in the present invention realizes the rotation of the inner and outer rings and the axial air supply, improves the radial bearing capacity of the hydrodynamic bearing, improves the stability of the bearing, has a wide range of applications, and has extensive promotion and use value.

[0017] 2. The axial air intake dynamic pressure air floating bearing described in the present invention adopts graphite lubrication and axial air intake to reduce friction resistance when rotating at low speed, improve wear resistance, and extend the service life of the dynamic pressure air floating bearing.

[0018] 3. The axial air intake dynamic pressure air floating bearing described in the present invention can be used in different scenarios, and is particularly suitable for equipment with internal air sources such as gas turbines and compressors. The high-pressure air generated inside can be used to greatly improve the bearing capacity and reduce friction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a general structural diagram of a dynamic pressure air bearing with axial air intake according to the present invention;

[0020] Figure 2 It is a cross-sectional view of a dynamic pressure air bearing with axial air intake according to the present invention;

[0021] Figure 3 It is a partial enlarged view of a dynamic pressure air bearing with axial air intake according to the present invention;

[0022] Figure 4 is the inner ring structure diagram of the present invention;

[0023] Figure 5 It is a cross-sectional view of the inner ring described in the present invention.

[0024] In the figure: 1-outer ring, 2-gap between inner and outer rings, 3-inner ring, 4-graphite, 5-inlet of gap between inner and outer rings, 6-outlet of gap between inner and outer rings, 7-first air intake channel, 8-second air intake channel, 9-inlet of first air intake channel, 10-inlet of second air intake channel, 11-outlet of second air intake channel. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is further described in detail below with reference to the accompanying drawings.

[0026] like Figures 1 to 5 As shown, the present invention provides an axial air intake hydrodynamic bearing, comprising an outer ring 1 and an inner ring 3, wherein there is an inner-outer ring gap 2 of 5-10 μm between the outer ring 1 and the inner ring 3 in the axial direction, and both the outer ring 1 and the inner ring 3 can rotate in cooperation with the rotor. The inner ring 3 is provided with a first air intake channel 7 and a second air intake channel 8. During operation, the external airflow enters the inner-outer ring gap 2 through the axial air intake mode, and at the same time, the first air intake channel 7 and the second air intake channel 8 continuously replenish the inner-outer ring gap 2, thereby improving the bearing capacity and stability of the hydrodynamic bearing. It is suitable for equipment with or without internal air source. In equipment with internal air source such as gas turbines, compressed air is introduced into the inner and outer ring gap 2, and combined with the first air inlet channel 7 and the second air inlet channel 8, sufficient air is continuously provided to the inner and outer ring gap 2 to improve the bearing capacity under low speed conditions, reduce friction, and cool the bearings throughout the process; in equipment without air source, the dynamic pressure air floating bearing is used to rotate itself to press air into the inner and outer ring gap 2, and the first air inlet channel 7 can increase the air intake volume of the inner and outer ring gap 2.

[0027] In order to better understand the present invention, the various structures of the present invention are introduced as follows.

[0028] like Figures 1 to 3 As shown, the outer ring 1 includes graphite 4, which is in block shape and embedded in the outer ring 1, mainly for lubrication, and the graphite 4 is evenly distributed along the circumference and radially penetrates the entire outer ring 1. Its main purpose is to increase the wear resistance of the contact surface between the outer ring and the inner ring and reduce friction under low-speed rotation conditions. The outer ring 1 is made of zirconia ceramic material to increase wear resistance. The inner and outer ring gap 2 includes an inner and outer ring gap inlet 5 and an inner and outer ring gap outlet 6. The inner and outer ring end faces of the inner and outer ring gap inlet 5 are chamfered to introduce gas.

[0029] like Figures 4 to 5 As shown, the inner ring 3 includes a first air inlet channel 7 and a second air inlet channel 8. The first air inlet channel 7 is a spiral guide groove. The first air inlet channel 7 is evenly distributed along the outer circumference of the inner ring 3. The first air inlet channel inlet 9 is located at the inlet 5 of the inner and outer ring gap of the inner ring 3, and the area of ​​the first air inlet channel 7 gradually decreases. The second air inlet channel 8 is a circular channel. The second air inlet channel inlet 10 is located at the air inlet end face of the inner ring 3. The second air inlet channel 8 is extended axially to the middle of the inner ring 3 and penetrates the inner ring 3 upward to form a second air inlet channel outlet 11. The second air inlet channel outlet 11 is staggered with the first air inlet channel 7. The airflow enters the inner and outer ring gap 2, and the area of ​​the second air inlet channel outlet 11 is smaller than the area of ​​the second air inlet channel inlet 10, thereby increasing the outlet flow rate.

[0030] Furthermore, the axial air intake and dynamic pressure air floating bearing described above adopts graphite lubrication, and combines the axial air intake and multi-channel air supply method to greatly improve the bearing capacity of the dynamic pressure air floating bearing and reduce friction resistance; in addition, since the inner and outer ring gap 2 is very small, a large friction loss will be generated, and the temperature of the inner and outer ring gap 2 will rise sharply. Through the axial air intake, the cold air can continuously force heat exchange in the inner and outer ring gap 2 to discharge the heat and improve the cooling effect.

[0031] Furthermore, in different embodiments, the first air inlet channel 7 has different requirements. In the device with an internal air source, the internal air is introduced into the inner and outer ring gap 2, and the air inlet direction of the first air inlet channel inlet 9 is the same as the air outlet direction of the air source; in the device without an air source, the air is pressed into the inner and outer ring gap 2 by its own rotation, and the air inlet direction of the first air inlet channel inlet 9 is opposite to the rotation direction.

[0032] Specifically, the axially air-inlet dynamic pressure air-floating bearing is particularly suitable for the field of gas turbine engines. It can greatly reduce the overall weight of the bearing, has a simple structure, and the compressed air of the compressor can meet its own use requirements, which can achieve the lightweight requirements of the gas turbine engine and propose a new solution for the application of dynamic pressure air-floating bearings in gas turbines and other aspects.

[0033] The above are only preferred specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field within the technical scope disclosed in the present invention, any equivalent replacement or change based on the technical solution and design concept of the present invention should be covered within the protection scope of the present invention.

Claims

1. A dynamic pressure air bearing with axial air intake, characterized in that: It comprises an outer ring and an inner ring which are fitted together, graphite is embedded in the outer ring, there is an inner-outer ring gap of 5-10 μm between the inner ring and the outer ring along the axial direction, the inner-outer ring gap is provided with an inner-outer ring gap inlet and an inner-outer ring gap outlet, the inner-outer ring end faces of the inner-outer ring gap inlet are provided with a chamfer for drainage, and both the outer ring and the inner ring can rotate in coordination with the rotor, a first air inlet channel and a second air inlet channel are provided on the inner ring, when working, the external air flow enters the inner-outer ring gap through the axial air inlet mode, and at the same time, the first air inlet channel and the second air inlet channel continuously replenish the inner-outer ring gap, thereby improving the bearing capacity and stability of the dynamic pressure air floating bearing; The first air intake channel is a spiral guide groove, which is evenly distributed along the outer circumference of the inner ring. The inlet of the first air intake channel is located at the inlet of the inner and outer ring gap of the inner ring, and is evenly arranged along the outer circumference of the inner ring. The first air intake channel adopts a variable cross-section channel, which gradually becomes narrower from wide.

2. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: The bearing is suitable for use in equipment with or without an internal air source. In equipment with an internal air source, compressed air is introduced into the gap between the inner and outer rings, and the first air inlet channel and the second air inlet channel are combined to continuously provide sufficient air for the gap between the inner and outer rings, while cooling the bearing at the same time. In equipment without an air source, the dynamic pressure air floating bearing is used to rotate itself to press air into the gap between the inner and outer rings, while the air intake volume of the gap between the inner and outer rings is increased through the first air inlet channel.

3. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: The outer ring is made of zirconium oxide ceramic.

4. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: Graphite for lubrication is evenly embedded in the outer ring. The graphite is evenly distributed in the circumferential direction and penetrates the entire outer ring radially.

5. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: The second air inlet channel has a circular cross section and is axially extended to the middle of the inner ring and penetrates the inner ring upward to form a second air inlet channel outlet. The second air inlet channel outlet is staggered with the first air inlet channel, and the airflow enters the gap between the inner and outer rings.

6. The axial air intake dynamic pressure air bearing according to claim 5, characterized in that: The outlet area of ​​the second air inlet passage is smaller than the inlet area of ​​the second air inlet passage, thereby increasing the outlet flow rate.

7. The axial air intake dynamic pressure air bearing according to claim 5, characterized in that: When the first air inlet channel is working in equipment with an air source inside a gas turbine or a compressor, the hydrodynamic air bearing uses the high-pressure air generated inside to directly introduce the compressor outlet air source into the gap between the inner and outer rings. At this time, the air inlet direction of the first channel is the same as the air outlet direction of the air source. In equipment without an air source, the hydrodynamic air bearing presses the gas into the gap between the inner and outer rings through its own rotation. At this time, the air inlet direction of the inlet of the first air inlet channel is opposite to the rotation direction.

8. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: The bearing can realize inner and outer ring rotation and axial air replenishment, thereby improving the radial bearing capacity of the hydrodynamic bearing.

9. The axial air intake dynamic pressure air bearing according to claim 1, characterized in that: The bearing adopts graphite lubrication and axial air intake, combined with multi-channel air supply, to reduce friction resistance when rotating at low speed, improve wear resistance, and extend the service life of the dynamic pressure air bearing.

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