A gas bearing turbocharger shafting arrangement

Abstract

A turbocharger shaft structure with air floating bearing comprises a rotating shaft, a synchronously rotating shaft sleeve is sleeved on the rotating shaft, a flange plate is arranged on the shaft sleeve near a compressor impeller; further comprising an intermediate body composed of a bearing seat, a bearing body and a bearing pressing plate, a first inner cavity is formed between the bearing seat and the bearing body, a second inner cavity is formed between the bearing body and the bearing pressing plate; the flange plate is arranged in the first inner cavity, and a pressure end air floating bearing is assembled in the space between one side of the flange plate and one side of the bearing body, a pressure end sleeve of the pressure end air floating bearing is sleeved on the shaft sleeve; the second inner cavity is assembled with a vortex end air floating bearing, a vortex end sleeve of the vortex end air floating bearing is sleeved on the shaft sleeve. In the technical solution, the outer circle of the shaft sleeve of the rotating shaft is matched with the two air floating bearings, the turbine rotating shaft and the shaft sleeve rotate synchronously to form an integral whole, and when rotating at high speed, the two air floating bearings and the shaft sleeve form a pressure air film to support the rotating system.

Description

Technical Field

[0001] This invention belongs to the field of turbocharger technology, specifically relating to a turbocharger shaft system structure with an air bearing. Background Technology

[0002] A turbocharger is a device used in automobile engines to increase their power output by compressing the air entering the engine. It is widely used in mid- to high-end cars. During operation, the shaft in the turbocharger rotates at high speed, driving the impeller to rotate.

[0003] In the existing technology, the turbocharger rotor system uses oil-floating bearings, which requires the design of lubrication oil circuits and sealing systems in the turbocharger intermediate body, resulting in a complex structure. Using air-floating bearings only requires the setting of cooling air circuits, resulting in a simple overall structure. Furthermore, the efficiency of oil-floating bearings is only 80% to 85% when the rotor system is running at high speed, while the shaft efficiency can reach over 95% when using air-floating bearings.

[0004] Currently, in some air bearing systems, the compressor impeller will have a pressure difference on both sides during operation, resulting in changes in axial force on the shaft system. Conventional turbocharger shaft systems also require the addition of thrust bearings, and the shaft has many installed parts, making the structure complex.

[0005] Therefore, based on the above situation, this application further designs and improves the shaft system structure of the air bearing turbocharger. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention provides a turbocharger shaft system structure with air bearings. The shaft system uses two air bearings as rotational supports and two thrust bearings to balance the axial force of the rotor system. Compared with the traditional turbocharger core body, which requires the arrangement of lubrication oil circuits, sealing systems, and cooling systems, the overall structure is simple.

[0007] The present invention is solved by the following technical solution.

[0008] A turbocharger shaft system structure with an air-bearing bearing includes a rotating shaft with a synchronously rotating bushing fitted on it. A flange is located on the bushing near the compressor impeller. The system also includes an intermediate body consisting of a bearing housing, a bearing body, and a bearing pressure plate. A first inner cavity is formed between the bearing housing and the bearing body, and a second inner cavity is formed between the bearing body and the bearing pressure plate. The flange is placed within the first inner cavity, and a pressure-end air-bearing bearing is assembled in the space between one side of the flange and one side of the bearing body. This pressure-end air-bearing bearing includes an integral pressure-end air-bearing bearing method. The first inner cavity consists of a flange and a pressure-end air bearing outer ring, which is fitted onto the bushing. The second inner cavity is equipped with a vortex-end air bearing, which includes an integral vortex-end air bearing flange and an outer ring, which is fitted onto the bushing. Arc-shaped foils are fixed to the inner walls of both the pressure-end air bearing outer ring and the vortex-end air bearing outer ring. Gas enters the first inner cavity from the outside, forming a gas film in the gap between the arc-shaped foils and the bushing. After flowing through the second inner cavity, the gas exits from the outlet on the bearing body.

[0009] In the technical solution of this application, the pressure end air bearing and the vortex end air bearing are respectively installed at both ends of the bearing body and fixed by bolts; the outer circle of the shaft sleeve cooperates with the two air bearings, and the turbine shaft and the shaft sleeve rotate synchronously to form a whole. When running at high speed, the arc-shaped foil in the two air bearings forms a pressure air film between the shaft sleeve and the rotor system to support the operation of the rotor system.

[0010] In a preferred embodiment, a thrust bearing is provided between one side of the flange and the side of the bearing housing; a thrust bearing is also provided between the other side of the flange and the side of the pressure end air bearing. In this application, a flange is designed on the bushing, and the two end faces of the flange are in contact with the thrust bearing. When the shaft rotates at high speed, a pressure air film is formed in the gap between the flange and the thrust bearing to balance the axial unbalanced force generated by the shaft system.

[0011] In a preferred embodiment, the thrust bearing includes a bearing base plate and a foil. The bearing base plate is positioned on the side of the bearing housing or on the side of the pressure end air bearing. The foil is located on the side of the flange, which has a compact structure, occupies little space, and can form a stable pressure air film in the gap between the bearing base plate and the foil.

[0012] In a preferred embodiment, the bearing housing has a first pin hole and a first air groove on its side, and the pressure-end air bearing has a second pin hole and a second air groove on its side, with a pressure-end vent hole in the second air groove; the bearing base plate has a pin slot and a through slot. In this structure, the bearing base plate can be positioned by inserting pins into the corresponding pin holes, facilitating assembly. The first air groove, the second air groove through slot, and the pressure-end vent hole are used for air passage.

[0013] In a preferred embodiment, an aligned through hole is provided between the pressure end air bearing and the bearing body for introducing gas into the intermediate inner cavity of the bearing body.

[0014] In a preferred embodiment, the vortex-end air bearing is provided with a channel for connecting the intermediate inner cavity and the second inner cavity for ventilation.

[0015] In a preferred embodiment, the bearing housing is fitted onto the bushing through an inner hole, and the inner surface of the inner hole is provided with a first toothed labyrinth structure; the bearing pressure plate is fitted onto one end of the rotating shaft through an inner hole, and the inner surface of the inner hole is provided with a second toothed labyrinth structure. Both the first and second toothed labyrinth structures are used to generate a certain sealing function. The principle is that several sequentially arranged annular sealing teeth are arranged around the rotating shaft, forming a series of intercepting gaps and expansion cavities between the teeth. The sealed medium experiences a throttling effect when passing through the gaps of the tortuous labyrinth, thus achieving the purpose of preventing leakage.

[0016] In a preferred embodiment, the rotating shaft is provided with at least two protruding interference fit sections, and a clearance section is provided between the two interference fit sections; the two interference fit sections are assembled in the inner holes at both ends of the bushing to reduce the weight of the entire rotor system so that it can adapt to higher speeds.

[0017] In a preferred embodiment, one end of the bushing is provided with a positioning plate, which can be positioned in the positioning groove at the end of the rotating shaft to achieve synchronous rotation of the bushing and the rotating shaft.

[0018] In a preferred embodiment, the arc-shaped foil is radially positioned by a groove on the inner diameter of the outer ring of the air bearing, and axially positioned by welded gaskets at both ends.

[0019] Compared with the prior art, the present invention has the following beneficial effects: It provides a turbocharger shaft system structure with air bearings. The shaft system is supported by two air bearings, and two thrust bearings balance the axial force of the rotor system. A total of four bearings are cooled by air entering through the air inlet of the bearing housing. Compared with the traditional turbocharger core body, which requires the arrangement of lubrication oil circuit, sealing system and cooling system, the overall structure is simple. The air bearings are non-contact when rotating at high speed, and the efficiency can reach more than 95%, which can improve the efficiency of the turbocharger. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the turbocharger in this invention.

[0021] Figure 2 This is a cross-sectional view of the shaft system in the turbocharger of the present invention.

[0022] Figure 3 for Figure 2 A magnified view of region A in the middle.

[0023] Figure 4 for Figure 2 A magnified view of region B in the middle.

[0024] Figure 5 The three-dimensional bearing housing in this invention Figure 1 .

[0025] Figure 6 The three-dimensional bearing housing in this invention Figure 2 .

[0026] Figure 7 The three-dimensional representation of the pressure-end air bearing in this invention Figure 1 .

[0027] Figure 8 The three-dimensional representation of the pressure-end air bearing in this invention Figure 2 .

[0028] Figure 9 The bearing body of the present invention is three-dimensional. Figure 1 .

[0029] Figure 10 The bearing body of the present invention is three-dimensional. Figure 2 .

[0030] Figure 11 This is a perspective view of the bearing pressure plate in this invention.

[0031] Figure 12 The three-dimensional representation of the vortex-end air bearing in this invention Figure 1 .

[0032] Figure 13 The three-dimensional representation of the vortex-end air bearing in this invention Figure 2 .

[0033] Figure 14 This is a perspective view of the thrust bearing structure in this invention.

[0034] Figure 15 This is a schematic diagram of the thrust bearing structure in this invention.

[0035] Figure 16 This is a perspective view of the two sets of thrust bearings in this invention.

[0036] Figure 17 This is a perspective view of the bearing substrate in this invention.

[0037] Figure 18 This is a perspective view of the bushing in this invention.

[0038] Figure 19 This is a perspective view of the rotating shaft in this invention.

[0039] Figure 20 This is a cross-sectional view of a portion of the shaft system assembly in this invention.

[0040] Figure 21 This is a schematic diagram of airflow in the shaft system assembly of the present invention.

[0041] Explanation of reference numerals in the attached drawings: 1: Compressor assembly; 2: Bearing housing; 3: Turbine assembly; 4: Shaft sleeve; 5: Pressure end air bearing; 6: Turbine end air bearing; 7: Shaft; 8: Bearing base plate; 11: Compressor impeller; 21: Inlet pipe; 22: Outlet; 23: Bearing housing; 24: Bearing pressure plate; 31: Turbine impeller; 41: Flange; 47: Positioning plate; 53: Second pin hole; 54: Second air groove; 55: Pressure end air bearing Bearing outer ring; 65: outer ring of vortex-end air bearing; 75: interference fit section; 77: positioning groove; 82: pin retaining groove; 83: through groove; 88: foil; 91: arc-shaped foil; 201: intermediate inner cavity; 231: first toothed labyrinth structure; 235: first pin hole; 236: first air groove; 241: second toothed labyrinth structure; 246: second inner cavity; 541: pressure end vent; 655: channel; 85: pin. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0043] In the following embodiments, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0044] See Figures 1 to 20This invention relates to an air-bearing turbocharger and its shaft system structure. Specifically, the turbocharger includes an intermediate body, a compressor assembly 1, and a turbine assembly 3. The shaft system structure includes a rotating shaft 7, on which a synchronously rotating bushing 4 is fitted. A flange 41 is provided on the bushing 4 near the compressor impeller 11 and away from the turbine impeller 31. It also includes an intermediate body composed of a bearing housing 23, a bearing body 2, and a bearing pressure plate 24. A first inner cavity is formed between the bearing housing 23 and the bearing body 2, and a second inner cavity is formed between the bearing body 2 and the bearing pressure plate 24. The flange 41 is placed in the first inner cavity, and a pressure-end air-bearing bearing 5 is assembled in the space between one side of the flange 41 and one side of the bearing body 2. The pressure-end air bearing 5 includes an integral pressure-end air bearing flange and a pressure-end air bearing outer ring 55, which is fitted onto the bushing 4. The second inner cavity 246 is equipped with a vortex-end air bearing 6, which includes an integral vortex-end air bearing flange and a vortex-end air bearing outer ring 65, which is fitted onto the bushing 4. Arc-shaped foils 91 are fixed to the inner walls of both the pressure-end air bearing outer ring 55 and the vortex-end air bearing outer ring 65, allowing gas to enter the first inner cavity from the outside. Figure 1 The air inlet pipe 21 shown forms an air film in the gap between the arc-shaped foil 91 and the bushing 4; after the gas flows through the second inner cavity 246, it flows out from the air outlet 22 on the bearing body 2. The air outlet 22 can be six that are evenly distributed in the circumference.

[0045] Specifically, in this application, a thrust bearing is provided between one side of the flange 41 and the side of the bearing housing 23; a thrust bearing is also provided between the other side of the flange 41 and the side of the pressure-end air bearing 5. In this application, the bushing 4 is designed with a flange 41, and the two end faces of the flange 41 are in contact with the thrust bearing. When the shaft rotates at high speed, a pressure air film is formed in the gap between the flange and the thrust bearing to balance the axial unbalanced force generated by the shaft system. The thrust bearing includes a bearing base plate 8 and a foil 88. The bearing base plate 8 is positioned on the side of the bearing housing 23 or on the side of the pressure-end air bearing 5; the foil 88 is located on the side of the flange 41. The structure is compact and occupies little space, and a stable pressure air film can be formed in the gap between the bearing base plate 8 and the foil 88.

[0046] Furthermore, the bearing housing 23 has a first pin hole 235 and a first air groove 236 on its side, and the pressure end air bearing 5 has a second pin hole 53 and a second air groove 54 on its side, with a pressure end vent hole 541 in the second air groove 54; the bearing base plate 8 has a pin slot 82 and a through slot 83. In this structure, the bearing base plate 8 can be positioned by inserting a pin 85 into the corresponding pin hole, which facilitates assembly. The first air groove 236, the second air groove 54, the through slot 83, and the pressure end vent hole 541 are used for ventilation.

[0047] In this application, the pressure-end air bearing 5 and the bearing body 2 are provided with aligned through holes for introducing gas into the intermediate inner cavity 201 in the bearing body 2. The vortex-end air bearing 6 is provided with a channel 655 for connecting the intermediate inner cavity 201 and the second inner cavity 246 for air passage.

[0048] In addition, from the appendix Figure 3 and attached Figure 4 It can also be seen that the bearing housing 23 is fitted onto the bushing 4 through an inner hole, and the inner surface of the inner hole is provided with a first toothed labyrinth structure 231; the bearing pressure plate 24 is fitted onto one end of the rotating shaft 7 through an inner hole, and the inner surface of the inner hole is provided with a second toothed labyrinth structure 241. Both the first toothed labyrinth structure 231 and the second toothed labyrinth structure 241 are used to generate a certain sealing function. The principle is to set a number of sequentially arranged annular sealing teeth around the rotating shaft. A series of intercepting gaps and expansion cavities are formed between the teeth. When the sealed medium passes through the gaps of the tortuous labyrinth, a throttling effect is generated to achieve the purpose of preventing leakage.

[0049] Furthermore, from the appendix Figure 18 and attached Figure 19 As can be seen from the attached diagram, one end of the bushing 4 is provided with a positioning plate 47, which can be positioned in the positioning groove 77 at the end of the rotating shaft 7 to achieve synchronous rotation of the bushing 4 and the rotating shaft 7. Figure 19 and attached Figure 20 As can be seen from the diagram, the rotating shaft 7 is provided with at least two protruding interference fit sections 75, and the space between the two interference fit sections 75 is a clearance section; the two interference fit sections 75 are assembled in the inner holes at both ends of the bushing 4 to reduce the weight of the entire rotor system so that it can adapt to higher speeds.

[0050] In this application, the arc-shaped foil 91 is radially positioned by a groove on the inner diameter of the outer ring of the air bearing, and axially positioned by welding gaskets at both ends.

[0051] As can be seen from the above description, the technical solution in this application is as follows: two air bearings are respectively installed in the central holes at both ends of the bearing body and fixed by bolts; the outer circle of the shaft sleeve is fitted with the air bearing, the turbine shaft component passes through the central hole of the sleeve and is interference-fitted, and a positioning plate 47 is added to the end face of the turbine shaft and the shaft sleeve to prevent relative movement between the shaft and the sleeve; the shaft and the sleeve form an integral whole, and after the impeller is installed, the impeller is fixed to the turbine shaft by the shaft end nut to form the entire rotor system.

[0052] During high-speed operation, a pressurized air film is formed between the air bearing and the bushing (shaft sleeve), supporting the operation of the rotor system. The shaft sleeve is designed with a flange, and the two end faces of the flange contact the thrust bearing. When the shaft rotates at high speed, a pressurized air film is formed in the gap between the flange and the thrust bearing to balance the axial unbalanced force generated by the shaft system.

[0053] During thrust bearing cooling, gas enters the installation gaps between the thrust bearing and the bearing housing, the air float bearing flange, and the shaft bearing flange for cooling. Simultaneously, air grooves are designed on the mating surfaces of the bearing housing and the air float bearing flange, allowing gas to enter the thrust bearing through the installation gaps and further enhancing cooling. Part of the gas enters the bearing housing through the vent holes on the air float bearing flange, while another part flows through the gaps within the air float bearing foils, cooling the pressure end air float bearing and entering the bearing housing. Then, the gas cools the air float bearing through the vent holes on the vortex end air float bearing flange. The airflow then enters the cavity formed between the bearing pressure plate and the bearing housing, carrying away heat transferred from the turbine end. Finally, the gas exits through the six exhaust holes on the bearing housing, completing the cooling of the entire turbocharger.

[0054] The vortex end gas seal is sealed by a sealing ring. The adjustment is to set a first toothed labyrinth structure and a second toothed labyrinth structure at the bearing housing and the inner hole of the bearing pressure plate for sealing. The principle is to set a number of sequentially arranged annular sealing teeth around the rotating shaft. A series of intercepting gaps and expansion cavities are formed between the teeth. When the sealed medium passes through the gaps of the tortuous labyrinth, a throttling effect is generated to achieve the purpose of preventing leakage.

[0055] Further explanation of the overall structure: Both the pressure-end air bearing and the vortex-end air bearing are positioned and installed through the central hole of the bearing body. Using the same hole for positioning and installation improves the coaxiality of the air bearing after installation, thus enhancing the stability of the shaft system during high-speed operation. The outer diameter of the bushing and the air bearing have a single-sided clearance of approximately 0.03 mm. During high-speed operation, an air film is generated at the clearance, allowing the air bearing to operate without contact with the shaft sleeve, improving the operating efficiency of the shaft system. The bushing has a flange structure that mates with the thrust bearings installed on both sides of the flange, with a single-sided clearance of 0.5 mm. During operation, the pressure difference on both sides of the compressor impeller back generates pressure that drives the rotor system to move. At this time, the pressure difference generated by the change in the thrust bearing installation clearance balances the pressure difference at both ends of the compressor impeller, maintaining the stability of the shaft system. If the pressure difference of the compressor impeller causes the shaft sleeve to move towards the bearing housing end, the gap between the thrust bearing at the bearing housing end and the shaft sleeve decreases, while the gap of the thrust bearing at the pressure end flange increases. The small gap of the thrust bearing at the bearing housing generates a large air film pressure, which pushes the shaft sleeve away from the bearing housing, thus balancing the shaft sleeve as a whole.

[0056] Ventilation grooves are designed on the contact surfaces of the bearing housing, the pressure end air bearing, and the thrust bearing to remove heat generated by the thrust bearing during operation. A bearing pressure plate is installed on the vortex end, forming part of the cooling air chamber together with the bearing body, and can also prevent the high-temperature gas from the vortex end from being conducted to the bearing body. A first toothed labyrinth structure 231 and a second toothed labyrinth structure 241 are provided in the inner holes of the bearing housing and the bearing pressure plate to reduce the leakage of high-temperature gas from the two wheels into the air bearing, which could lead to high-temperature failure of the air bearing, through the throttling effect. The turbine shaft component and the shaft sleeve are interference-fitted, and a positioning groove is designed at the axial mating end face of the shaft sleeve and the turbine shaft component to effectively prevent relative rotation of the two parts at high speed.

[0057] Because of its larger diameter, the thrust bearing generates a higher tangential velocity in the air film. Therefore, air grooves are added to the bearing housing and the air bearing flange to enhance the cooling of the thrust bearing. The thrust bearing is radially positioned and prevented from rotating by six cylindrical pins, resulting in a simple structure. The cooling gas then passes through the gap between the air bearing and the shaft sleeve, and through the air bearing flange and the bearing body vents to enter the intermediate cavity of the bearing body. It then cools the vortex air bearing through the vents on the vortex air bearing flange, enters the cavity formed by the bearing pressure plate and the bearing body, cools the bearing pressure plate, and carries away the heat transferred from the turbine end. Finally, the gas is discharged from the six exhaust holes on the bearing body, completing the entire cooling cycle.

[0058] The thrust bearing is located at the compressor end, away from the influence of the vortex end heat load, thus increasing its service life. The pressure end air bearing integrates the thrust bearing mounting plate and adds cooling air grooves and other structures, resulting in a simple structure.

[0059] The turbine shaft assembly and the shaft sleeve have only interference contact at both ends, and the shaft diameter in the middle is reduced to reduce the weight of the entire rotor system so that it can adapt to higher speeds. At the same time, reducing the interference section can reduce the assembly difficulty and improve assemblability. In addition, the reduced shaft diameter at the weld with the turbine can reduce the transfer of heat from the turbine end to the pressure end and reduce the thermal load on the turbine end air bearing.

[0060] For a detailed airflow path diagram, please refer to Figure 21 The diagram shows the airflow in the shaft assembly: the red arrows indicate the gas flow direction. It can be seen that gas enters the bearing housing 23 from the upper intake pipe 21, and then some gas enters the thrust bearing, generating a gas film; some gas also generates a gas film at the arc-shaped foil 91; the remaining gas enters the middle inner cavity 201 of the bearing body 2 through the pressure end vent 541 on the pressure end air bearing 5. Figure 21 As shown by the horizontal arrow in the middle. Then, the gas in the middle inner cavity 201 enters the second inner cavity 246 through the channel 655 on the vortex end air bearing 6, and finally exits through the outlet 22, that is... Figure 21 As shown by the three arrows on the right side of the middle.

[0061] As described above, this invention provides a turbocharger shaft system structure with air bearings. The shaft system uses two air bearings as rotational supports and two thrust bearings to balance the axial force of the rotor system. A total of four bearings are cooled by air entering through the air inlet of the bearing housing. Compared with traditional turbocharger core bodies that require the arrangement of lubrication oil circuits, sealing systems, and cooling systems, the overall structure is simple. The air bearings are non-contact when rotating at high speeds, and the efficiency can reach over 95%, which can improve the efficiency of the turbocharger.

[0062] The scope of protection of this invention includes, but is not limited to, the above embodiments. The scope of protection of this invention is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art fall within the scope of protection of this invention.

Claims

1. A shaft system structure for an air-bearing turbocharger, characterized in that, Includes a rotating shaft (7), on which a synchronously rotating bushing (4) is fitted, and a flange (41) is provided on the bushing (4) near the compressor impeller (11). It also includes an intermediate body consisting of a bearing housing (23), a bearing body (2), and a bearing pressure plate (24), wherein a first inner cavity is formed between the bearing housing (23) and the bearing body (2), and a second inner cavity is formed between the bearing body (2) and the bearing pressure plate (24); The flange (41) is placed in the first inner cavity, and a pressure end air bearing (5) is assembled in the space between one side of the flange (41) and one side of the bearing body (2). The pressure end air bearing (5) includes an integral pressure end air bearing flange and a pressure end air bearing outer ring (55), and the pressure end air bearing outer ring (55) is sleeved on the bushing (4). The second inner cavity (246) is equipped with a vortex end air bearing (6), which includes an integral vortex end air bearing flange and a vortex end air bearing outer ring (65), which is sleeved on the bushing (4). Arc-shaped foils (91) are fixed on the inner walls of the outer ring (55) of the pressure end air bearing and the outer ring (65) of the vortex end air bearing. Gas enters the first inner cavity from the outside and forms an air film in the gap between the arc-shaped foil (91) and the bushing (4). After the gas flows through the second inner cavity (246), it flows out from the air outlet (22) on the bearing body (2).

2. The air-bearing turbocharger shaft system structure according to claim 1, characterized in that, A thrust bearing is provided between one side of the flange (41) and the side of the bearing housing (23); a thrust bearing is provided between the other side of the flange (41) and the side of the pressure end air bearing (5).

3. The air-bearing turbocharger shaft system structure according to claim 2, characterized in that, The thrust bearing includes a bearing base plate (8) and a foil (88). The bearing base plate (8) is positioned on the side of the bearing housing (23) or on the side of the pressure end air bearing (5). The foil (88) is located on the side of the flange (41).

4. The air-bearing turbocharger shaft system structure according to claim 3, characterized in that, The bearing housing (23) has a first pin hole (235) and a first air groove (236) on its side. The pressure end air bearing (5) has a second pin hole (53) and a second air groove (54) on its side. The second air groove (54) has a pressure end vent hole (541). The bearing base plate (8) has a pin slot (82) and a through slot (83).

5. The air-bearing turbocharger shaft system structure according to claim 4, characterized in that, The pressure end air bearing (5) and the bearing body (2) are provided with aligned through holes for introducing gas into the intermediate inner cavity (201) in the bearing body (2).

6. The air-bearing turbocharger shaft system structure according to claim 5, characterized in that, The vortex-end air bearing (6) is provided with a channel (655) for connecting the intermediate inner cavity (201) and the second inner cavity (246).

7. A turbocharger shaft system structure with air bearing according to any one of claims 1 to 6, characterized in that, The bearing housing (23) is fitted onto the bushing (4) through an inner hole, and a first toothed labyrinth structure (231) is provided on the inner surface of the inner hole; the bearing pressure plate (24) is fitted onto one end of the rotating shaft (7) through an inner hole, and a second toothed labyrinth structure (241) is provided on the inner surface of the inner hole.

8. A turbocharger shaft system structure with an air bearing according to any one of claims 1 to 6, characterized in that, The rotating shaft (7) is provided with at least two protruding interference fit sections (75), and there is a clearance section between the two interference fit sections (75); the two interference fit sections (75) are assembled in the inner holes at both ends of the bushing (4).

9. A turbocharger shaft system structure with an air bearing according to any one of claims 1 to 6, characterized in that, One end of the bushing (4) is provided with a positioning plate (47), which can be positioned in the positioning groove (77) at the end of the rotating shaft (7) to realize the synchronous rotation of the bushing (4) and the rotating shaft (7).

10. A turbocharger shaft system structure with air bearing according to any one of claims 1 to 6, characterized in that, The arc-shaped foil (91) is radially positioned by a groove on the inner diameter of the outer ring of the air bearing, and axially positioned by welding gaskets at both ends.

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