Tile type spiral groove gas bearing

Abstract

The utility model discloses a tile type spiral groove gas bearing, which relates to the technical field of radial dynamic pressure gas bearings and comprises a bearing rotor, a tile layer and a bearing outer ring which are sequentially arranged from inside to outside, a plurality of groups of grooves are formed in the inner side of the tile layer, the grooves are distributed in an annular array by taking the central axis of the tile layer as the axis, and the two grooves in the same group are symmetrically arranged by taking the axial central surface of the bearing rotor as the axis and form an included angle; and the tile layer is connected to the bearing outer ring in a limiting manner. Through the arrangement, the bearing capacity and the stability of the bearing are improved by selecting the spiral groove tiles which are obliquely distributed along the radial direction.

Description

Technical Field

[0001] The utility model relates to the technical field of radial hydrodynamic gas bearings, in particular to a tile-type spiral groove gas bearing. Background Art

[0002] An air compressor is an important component of a vehicle-mounted hydrogen fuel cell. Due to its high pressure ratio, small volume, oil-free, high power, and compact structure, a centrifugal air compressor has broad application prospects. The air compressor suitable for hydrogen fuel cells needs to have high power, high rotational speed of the bearing rotor, and at the same time meet the oil-free characteristics. The spiral groove gas bearing can well meet these requirements of the air compressor, and its accuracy is also higher.

[0003] The working principle of the spiral groove gas bearing is to use the gas moving in the spiral groove to generate an extremely thin high-pressure gas film to achieve the lubrication and support of the rotor. When the shaft rotates, the gas is compressed and expanded under the guidance of the spiral groove, thereby forming a stable gas film on the bearing surface. This gas film can effectively eliminate the friction and wear between the shaft and the bearing, improve the service life of the bearing, and compared with other types of gas bearings, the spiral groove gas bearing also has higher stability and load-bearing capacity. In addition, it also has the characteristics of low noise and oil-free, and can be applied to various high-speed precision machinery.

[0004] If the spiral groove gas bearing wants to compress the gas to generate a hydrodynamic effect, then there must be relative movement between the upper and lower boundaries of the gas film. The traditional spiral groove gas bearing engraves the groove on the bearing rotor, and the spiral groove rotates with the bearing rotor, while the bearing outer ring remains stationary, so as to form a gas pressure film to support the bearing rotor to work. The rotational speed of the air compressor adapted to the vehicle-mounted hydrogen fuel cell is extremely high, up to 200000 rpm, which places extremely high requirements on the performance of the bearing rotor. Materials with higher hardness, such as ceramic materials and high-hardness alloys, are often selected, so that the difficulty of engraving grooves on it is relatively large, the process technology requirements are relatively high, and the corresponding cost is also relatively high.

[0005] The selection of the bearing rotor material is relatively demanding and the cost is relatively expensive. The selection range of the bearing outer ring material is wider, and the cost of its material is relatively low and the processing is relatively simple. If the spiral groove is engraved on the inner side of the bearing outer ring of the bearing rotor, when the bearing rotor rotates at a high speed and the spiral groove remains stationary with the bearing outer ring, a gas pressure film can also be formed to support the bearing rotor to work. Directly engraving the spiral groove on the inner side of the bearing outer ring has relatively high processing difficulty and cost. However, if the spiral groove is manufactured and processed in blocks and then assembled on the inner side of the bearing outer ring, the processing difficulty and cost can be greatly simplified. Summary of the Utility Model

[0006] The purpose of the present utility model is to solve the defects existing in the prior art, and a tile-type spiral groove gas bearing is proposed.

[0007] In order to achieve the above purpose, the present utility model adopts the following technical solutions:

[0008] A tile-type spiral groove gas bearing includes a bearing rotor, a tile layer, and a bearing outer ring arranged in sequence from inside to outside; a plurality of groups of grooves are formed on the inner side of the tile layer, and the grooves are arranged in a circular array with the axis of the tile layer as the axis. Two grooves in the same group are symmetrically arranged with respect to the axial center plane of the bearing rotor and form an included angle; the tile layer is limitedly connected to the bearing outer ring.

[0009] Further, the tile layer includes three tiles connected end to end. The cross-section of the tile is arc-shaped, and the arc angle is 120°. A limit protrusion is arranged at the edge position of the end face of the tile close to the bearing outer ring, and a limit groove is formed on the inner wall of the bearing outer ring, and the limit groove is adapted to the limit protrusion.

[0010] Furthermore, the grooves in the same group are connected and intersect at the axial center plane of the bearing rotor.

[0011] Furthermore, there is a gap between the grooves in the same group.

[0012] Furthermore, the thickness of the tile gradually decreases from the first side to the second side. The first side of the tile is connected to the second side of its adjacent tile, and limit protrusions are arranged at the end faces of the first side and the second side of the tile close to the bearing outer ring.

[0013] Further, the thickness of the tile is the same from the first side to the second side, and limit protrusions are arranged at the end faces of the first side and the second side of the tile close to the bearing outer ring.

[0014] Further, a wear-resistant coating is provided on the inner wall of the tile layer and / or the tile layer is made of wear-resistant material.

[0015] Further, a platform area is formed between adjacent groups of grooves, and the platform area is arranged parallel to the grooves.

[0016] Beneficial effects

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] 1. Adopting a segmented spiral groove structure, the spiral grooves are engraved on the inner surface of a cylindrical structure composed of three tiles, which improves the service life of the bearing rotor.

[0019] 2. The segmented spiral groove tiles can be manufactured using relatively inexpensive materials and have relatively low technical requirements during processing. When the grooves are worn, the tiles can be directly replaced, which helps reduce the manufacturing cost while ensuring the service life of the entire spiral groove gas bearing.

[0020] 3. Selecting spiral groove tiles with a radially inclined distribution can also improve the bearing capacity and stability of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0022] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present invention.

[0023] Figure 2 It is a side view of Embodiment 1 of the present invention.

[0024] Figure 3 It is a schematic structural diagram of the cooperation between the tile and the bearing outer ring in Embodiment 1 of the present invention.

[0025] Figure 4 It is a schematic structural diagram of the tile in Embodiment 1 of the present invention.

[0026] Figure 5 It is a side view of the tile in Embodiment 1 of the present invention.

[0027] Figure 6 It is a schematic structural diagram of the bearing rotor in Embodiments 1 and 2 of the present invention.

[0028] Figure 7 It is a schematic structural diagram of the bearing outer ring in Embodiments 1 and 2 of the present invention.

[0029] Figure 8 It is a schematic structural diagram of Embodiment 2 of the present invention.

[0030] Figure 9 It is a side view of Embodiment 2 of the present invention.

[0031] Figure 10 It is a schematic structural diagram of the cooperation between the tile and the bearing outer ring in Embodiment 2 of the present invention.

[0032] Figure 11 It is a schematic structural diagram of the tile in Embodiment 2 of the present invention.

[0033] Figure 12 It is a side view of the tile in Embodiment 2 of the present invention.

[0034] In the figure: 1. Bearing rotor; 2. Bearing outer ring; 3. Pad. Specific embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0036] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0037] Embodiment 1:

[0038] Refer to Figure 1 - Figure 7 : An easily installed tile-type spiral groove gas bearing, including a bearing rotor 1, pads 2 and a bearing outer ring 3.

[0039] The inner surface of the cylindrical structure formed by three pads is provided with a plurality of spiral grooves evenly distributed in the circumferential direction. The grooves are distributed along the cylindrical spiral line direction, and the spiral grooves are symmetric about the axial center plane. There is a gap in the middle of the grooves at both ends of the bearing and they do not meet in the middle of the bearing. The distance from the inner cylindrical surface of the cylindrical structure formed by the three pads 3 to the axis of the bearing rotor is the same. The area between two adjacent grooves forms a stepped structure.

[0040] The bearing rotor 1 is arranged inside the cylindrical structure formed by the three pads 3 and a gap is provided. The inner surface of the pad is provided with a wear-resistant coating. The outer surface of the pad 3 is attached to the inner surface of the bearing outer ring 2 and is fixedly connected through the edge on the outer surface of the pad 3 and the groove on the inner surface of the bearing outer ring 2.

[0041] When the gas bearing rotates during operation, there is a certain eccentricity. Due to viscosity, the gas is driven by the rotor and flows into the wedge-shaped area formed by the cylindrical structure composed of the bearing rotor 1 and the pads 3. The volume of the gas decreases and the pressure increases, and the pressure of the gas film supports the load of the rotor.

[0042] The grooves and the steps between the grooves on the inner surface of the cylindrical structure formed by the pads 3 form a second wedge-shaped area. The gas flows from the groove area into the step area, the volume further decreases, the gas film pressure further increases, and the supporting force for the bearing rotor 1 is further strengthened.

[0043] For the grooves distributed along the cylindrical helix, when the gas flows from the groove area to the platform area, it will also flow from both ends to the middle along the direction of the grooves of the cylindrical structure composed of the tiles 3, and finally converge at the central symmetry plane of the cylindrical structure composed of the tiles 3. Since the gas at both ends of the bearing flows towards the middle, the gas at both ends decreases, and gas will be continuously inhaled outside the bearing, ultimately reaching a dynamic balance.

[0044] Since the groove areas at both ends of the bearing do not converge, when the gas is driven by the bearing rotor 1 to rotate, it will flow from both ends of the bearing towards the middle, but stop flowing near the central symmetry plane of the bearing and gather at the ends of the grooves. The pressure at the ends of the groove areas of the cylindrical structure composed of the tiles 3 will increase, and finally a ring-shaped air film with a higher pressure will be formed at both ends of the central symmetry plane of the cylindrical structure composed of the tiles 3.

[0045] Since the grooves on both sides of the inner surface of the cylindrical structure composed of the tiles 3 are not connected, if the gas states on both sides are different, the pressures of the two ring-shaped air films may also be different, which will generate a torque causing the bearing rotor 1 to rotate, and will cause a certain interference to its stability. However, precisely because its grooves are not connected, the pressures of the two generated ring-shaped air films will be greater, making the bearing capacity of the bearing stronger.

[0046] The cylindrical structure composed of the tiles 3 is formed by splicing three tiles together, so there will inevitably be extremely small gaps at the splicing points during installation. When the bearing is working, the high-pressure gas will escape from these gaps, resulting in a slight reduction in the air film pressure. However, due to its segmented processing and installation method, it will greatly simplify the manufacturing and processing of the bearing, and extend the service life of the bearing, reducing costs.

[0047] The structure of the present utility model is simple, the design of the spiral grooves is reasonable, the bearing capacity and stability are high. It utilizes the segmented spiral groove structure, reduces the difficulty and cost of bearing manufacturing and processing, and also improves the service life of the bearing.

[0048] Embodiment 2:

[0049] Refer to Figure 7 - Figure 12 : The difference from Embodiment 1 is that an easily installed tile-type spiral groove gas bearing includes a bearing rotor 1, tiles 2, and a bearing outer ring 3.

[0050] Multiple spiral grooves evenly distributed along the circumferential direction are provided on the inner surface of the cylindrical structure composed of three tiles. The grooves are distributed along the direction of the cylindrical helix, and the spiral grooves are symmetric about the axial central plane. There is no gap in the middle of the grooves at both ends of the bearing, and they meet at the middle of the bearing. The distances from the inner cylindrical surface of the cylindrical structure composed of the three tiles 2 to the axis of the bearing rotor are different.

[0051] When a gas dynamic pressure bearing rotates, there is a certain eccentricity. The cylindrical structure composed of the bearing rotor 1 and the pad 2 forms a first wedge region, and the platforms between the grooves on the inner surface of the cylindrical structure composed of the pads 3 form a second wedge region. When the spiral grooves provided on the inner surface of the cylindrical structure composed of the three pads 2 are circumferentially inclined, each pad and the rotor will form a third wedge region, further strengthening the compression of the gas by the bearing, increasing the pressure of the gas film, and further enhancing the bearing capacity of the bearing.

[0052] When the bearing works, the gas flows from both ends to the middle along the direction of the grooves of the cylindrical structure composed of the three pads 2 and finally converges at the symmetric plane in the middle. Since the grooves at both ends of the cylindrical structure composed of the three pads 2 are connected, the pressures at both ends of the bearing are balanced with each other, solving the influence of the rotational torque caused by different pressures at both ends and improving the stability of the bearing. However, the bearing capacity will decrease compared with the grooves that are not interconnected at both ends. The distribution type of the grooves needs to be selected according to the actual requirements.

[0053] The above is only the preferred specific implementation mode of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the technical solution of the present utility model and its inventive concept, makes equivalent substitutions or changes, and should be covered by the protection scope of the present utility model.

Claims

1. A tile-type spiral groove gas bearing, characterized in that: It includes a bearing rotor, a tile layer and a bearing outer ring which are arranged in sequence from the inside to the outside; a plurality of groups of grooves are provided on the inner side of the tile layer, the grooves are arranged in a ring array with the central axis of the tile layer as the axis, and two grooves in the same group are symmetrically arranged with respect to the axial center plane of the bearing rotor and form an angle; the tile layer is limit-connected to the bearing outer ring.

2. A tile type spiral groove gas bearing according to claim 1, characterized in that: The tile layer includes three groups of tiles connected end to end, the tile cross-section is arc-shaped, and the arc angle is 120°. A limiting protrusion is provided at the edge of the end face of the tile adjacent to the outer ring of the bearing, and a limiting groove is provided on the inner wall of the outer ring of the bearing, and the limiting groove is adapted to the limiting protrusion.

3. A tile type spiral groove gas bearing according to claim 2, characterized in that: The grooves in the same group are connected and intersect at the axial center plane of the bearing rotor.

4. A tile type spiral groove gas bearing according to claim 2, characterized in that: There are intervals between the grooves in the same group.

5. A tile type spiral groove gas bearing according to claim 3 or 4, characterized in that: The thickness of the tile gradually decreases from the first side to the second side, the first side of the tile is connected to the second side of its adjacent tile, and the end faces of the first side and the second side of the tile adjacent to the outer ring of the bearing are both provided with limiting protrusions.

6. A tile type spiral groove gas bearing according to claim 3 or 4, characterized in that: The thickness of the tile is the same from the first side to the second side, and the end faces of the first side and the second side of the tile adjacent to the outer ring of the bearing are both provided with limiting protrusions.

7. The tile type spiral groove gas bearing according to claim 1, characterized in that: The inner wall of the tile layer is provided with a wear-resistant coating and / or the tile layer is made of a wear-resistant material.

8. The tile type spiral groove gas bearing according to claim 1, characterized in that: Lands are formed between adjacent groups of grooves, and the lands are arranged parallel to the grooves.

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