Centrifugal air compressor rotor structure with split type dynamic pressure gas thrust bearing

Abstract

The utility model discloses a centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing. The centrifugal air compressor rotor structure comprises a main shaft, an impeller, a radial dynamic pressure gas bearing, the split type dynamic pressure gas thrust bearing, a thrust plate, a magnet and a rotor sheath, dynamic pressure gas bearings on the main shaft are sequentially arranged according to the sequence of a first-stage side radial dynamic pressure gas bearing, a first-stage side split type dynamic pressure gas thrust bearing, a second-stage side split type dynamic pressure gas thrust bearing and a second-stage side radial dynamic pressure gas bearing, and the first-stage side radial dynamic pressure gas bearing and the second-stage side radial dynamic pressure gas bearing are distributed on the two sides of a thrust disc. A radial supporting structure of the rotor is formed, the thrust plate and the main shaft are assembled in a hot charging mode to form an interference fit structure, or the thrust plate and the main shaft are machined into an integrated piece, and the structure simplifies the tedious step of replacement after a bearing on the inner side of the thrust plate is abraded. And meanwhile, by adopting the design of the split type thrust bearing, the foils are distributed more uniformly, and the bearing capacity and the heat dissipation performance are remarkably improved.

Description

Technical Field

[0001] The utility model relates to the fields of gas bearings and high-speed rotating machinery, in particular to a novel centrifugal air compressor rotor structure with a split-type dynamic pressure gas thrust bearing. Background Art

[0002] Current research indicates that in the field of high-speed rotating machinery, hydrodynamic gas bearings offer excellent stability and reliability, as well as excellent load-bearing capacity and service life. Specific applications include high-speed centrifugal air compressors and high-speed turbine expanders. Recent years of research on this technology have revealed diverse and variable results in terms of both foil structure and materials for foil hydrodynamic gas thrust bearings. However, in actual production applications, the production of foil lags behind the theoretical analysis of most foil hydrodynamic gas bearings. Consequently, there is a lack of unified standards and serialized production guidelines for foil hydrodynamic gas bearings used in high-speed rotating machinery. Different companies and researchers use structural design methods tailored to their specific high-speed rotating machinery, resulting in varying bearing structures.

[0003] Existing research has investigated foil dynamic pressure gas bearings used in high-speed rotating machinery, including radial bearings and axial thrust bearings. In centrifugal compressor rotor systems, most foil dynamic pressure gas bearings are currently positioned with the primary and secondary radial bearings on the same side of the thrust plate. These bearings utilize a centralized, integrated thrust bearing structure, requiring the thrust plate to be shrink-fitted to the main shaft. This shrink-fit method involves making the thrust plate's inner diameter slightly smaller than the main shaft diameter. The thrust plate is heated, causing it to expand, facilitating installation onto the main shaft. During cooling, the thrust plate's inner diameter shrinks evenly, creating an interference fit on the main shaft. Because the radial bearing and one thrust bearing are located inside the thrust plate, removing or replacing the bearings requires heating and removing the thrust plate and thrust bearing first. This repeated, localized high-temperature heating of the thrust plate during each removal and installation can damage the gas bearing's foil. Frequent removal and installation of the thrust plate also damages and destroys the thrust plate and main shaft, increasing the replacement and maintenance costs of the rotor system.

[0004] Therefore, we invented a new type of centrifugal air compressor rotor structure with a split hydrodynamic gas thrust bearing. The two-stage radial bearings of the main shaft are placed on both sides of the thrust plate, and are matched with a split hydrodynamic gas thrust bearing. By adjusting the position distribution of the radial bearings, the pain point of having to remove the thrust plate and thrust bearing every time the radial hydrodynamic gas bearing is removed and replaced is solved. In addition, the thrust bearing adopts a split tile structure, which evenly distributes the foil of the thrust bearing on the tile surface, effectively improving the bearing capacity and heat dissipation capacity of the thrust bearing, and also solves the problem that the thrust bearing foil on the inner side of the thrust plate is difficult to replace after wear and damage. With this innovative structure, the thrust plate can be processed into an integral part with the main shaft, and no disassembly and assembly is required. The integrated structure of the thrust plate and the main shaft improves the stability of the rotor system and avoids the problem of the traditional hot-fit structure that the structural deformation of the rotor under overspeed conditions causes the thrust plate and the main shaft to loosen, greatly improving the reliability and safety of the rotor system. The manufacturing process of the split-type foil dynamic pressure gas thrust bearing is easy and has a standardized and serialized structure, which is conducive to improving the standard regulations and serialized production guidelines of the foil dynamic pressure gas bearing. Summary of the Invention

[0005] The present utility model aims to provide a centrifugal air compressor rotor structure with a split-type dynamic pressure gas thrust bearing. By improving the bearing's position distribution, structural form, and installation method, a split-type foil dynamic pressure gas thrust bearing structure is introduced. Compared to traditional integral and centralized welded structures, the bearing components on the centrifugal air compressor rotor structure are easier to replace and disassemble, simplifying the process flow. The standardized and serialized structure facilitates the improvement of standard regulations and serialized production guidelines for foil dynamic pressure gas bearings. Furthermore, the split-type thrust bearing design allows for a more even distribution of the foil, significantly improving both load-bearing capacity and heat dissipation capabilities.

[0006] In order to achieve the above purpose, the utility model proposes the following technical solution: a centrifugal air compressor rotor structure with a split dynamic pressure gas thrust bearing, characterized in that the structure includes a main shaft (1), a first-stage impeller (2), a first-stage radial dynamic pressure gas bearing (3), a first-stage split dynamic pressure gas thrust bearing (4), a thrust plate (5), a second-stage split dynamic pressure gas thrust bearing (6), a magnet and a rotor sleeve (7), a second-stage radial dynamic pressure gas bearing (8), and a second-stage impeller (9), wherein the dynamic pressure gas on the main shaft (1) The bearings are arranged in the order of a primary side radial dynamic pressure gas bearing (3), a primary side split dynamic pressure gas thrust bearing (4), a secondary side split dynamic pressure gas thrust bearing (6) and a secondary side radial dynamic pressure gas bearing (8). The primary side radial dynamic pressure gas bearing (3) and the secondary side radial dynamic pressure gas bearing (8) are distributed on both sides of the thrust plate (5) to form a radial support structure of the rotor. The thrust plate (5) and the main shaft (1) are assembled by heat-fitting to form an interference fit structure, or the thrust plate (5) and the main shaft (1) are processed into an integral part.

[0007] A centrifugal air compressor rotor structure with a split-type dynamic pressure gas thrust bearing is characterized in that the first-side split-type dynamic pressure gas thrust bearing and the second-side split-type dynamic pressure gas thrust bearing can be respectively composed of three to eight evenly distributed fan-shaped tiles, which are fixed to the shell with pins or screws, the gaps between the tiles are of uniform size, and the elastic foil and the flat foil are superimposed in sequence on the tile plane.

[0008] Furthermore, the elastic foil used for the primary side radial dynamic pressure gas bearing, the primary side split dynamic pressure gas thrust bearing, the secondary side split dynamic pressure gas thrust bearing and the secondary side radial dynamic pressure gas bearing can be a corrugated foil type, a metal mesh type, a bubble type, a broken wall protrusion type, or a multi-support arm type.

[0009] Furthermore, the split-type dynamic pressure gas thrust bearing has a pad (43) that can be fixed to the housing by pins, or a pad (43) that can be fixed to the integral bearing seat by threads, and then the bearing seat is fixed to the housing by screws. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the centrifugal air compressor rotor structure with a split hydrodynamic gas thrust bearing.

[0011] Figure 2 The present invention is a structural schematic diagram of a primary side split type dynamic pressure gas thrust bearing used in a centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing. DETAILED DESCRIPTION

[0012] In order to enable those skilled in the art to better understand the purpose, technical solutions and advantages of the present invention, the technical solutions in the embodiments of the present invention will be described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0013] like Figure 1 As shown, the utility model provides a centrifugal air compressor rotor structure with a split dynamic pressure gas thrust bearing, including a main shaft 1, a first-stage impeller 2, a first-stage radial dynamic pressure gas bearing 3, a first-stage split dynamic pressure gas thrust bearing 4, a thrust plate 5, a second-stage split dynamic pressure gas thrust bearing 6, a magnet and a rotor sleeve 7, a second-stage radial dynamic pressure gas bearing 8, and a second-stage impeller 9. The dynamic pressure gas bearing on the main shaft 1 is divided into the first-stage radial dynamic pressure gas bearing 3, the first-stage split dynamic pressure gas thrust bearing 4, and the second-stage split dynamic pressure gas thrust bearing. The first-stage split-type dynamic pressure gas thrust bearing 4 is centrally symmetrical with the second-stage bearing 5. When the radial bearings 3 and 4 need to be replaced due to wear and tear, the bearings can be directly disassembled and replaced, which solves the problem that the two-stage radial bearings 3 and 8 are located on the same side of the thrust plate 5 and the thrust plate 5 still needs to be disassembled first. The process flow is simplified, and the thrust plate 5 can be processed into an integral part with the main shaft 1, adopting an integrated thrust rotor structure, which has better axial load-bearing capacity and working stability.

[0014] like Figure 2 As shown, the flat foil 41 and the elastic foil 42 are fixed on the tile 43 through their straight sections; when fixed, the inner circles of the flat foil 41 and the elastic foil 42 coincide with the inner cylindrical surface of the tile 43, and the edges of the straight sections of the foils maintain a certain distance from the edge sides of the tile 43; pin holes are processed on the surface of the tile 43 to fix the relative positions of each tile 43 and ensure the overall uniformity of the bearing. When the flat foil 41, the elastic foil 42 and the tile 43 have positioning problems or damage, the worn parts can be disassembled and replaced separately without disassembling the thrust plate 5, so as to simplify the process flow, be convenient and quick, improve the processing and maintenance efficiency and reduce the defective rate.

Claims

1. A centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing, characterized in that: The structure comprises a main shaft (1), a first-stage impeller (2), a first-stage radial dynamic pressure gas bearing (3), a first-stage split dynamic pressure gas thrust bearing (4), a thrust plate (5), a second-stage split dynamic pressure gas thrust bearing (6), a magnet and a rotor sleeve (7), a second-stage radial dynamic pressure gas bearing (8), and a second-stage impeller (9), wherein the dynamic pressure gas bearings on the main shaft (1) are arranged in the order of the first-stage radial dynamic pressure gas bearing (3), the first-stage split dynamic pressure gas thrust bearing (4), the second-stage split dynamic pressure gas thrust bearing (6), and the second-stage radial dynamic pressure gas bearing (8); the first-stage radial dynamic pressure gas bearing (3) and the second-stage radial dynamic pressure gas bearing (8) are distributed on both sides of the thrust plate (5) to form a radial support structure of the rotor; the thrust plate (5) and the main shaft (1) are assembled by heat-fitting to form an interference fit structure, or the thrust plate (5) and the main shaft (1) are processed into an integral part.

2. The centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing according to claim 1, characterized in that: The first-side split-type dynamic pressure gas thrust bearing (4) and the second-side split-type dynamic pressure gas thrust bearing (6) can each be composed of three to ten evenly distributed fan-shaped tiles (43), the gaps between the tiles (43) are of uniform size, and the elastic foil (42) and the flat foil (41) are sequentially superimposed on the plane of the tiles (43).

3. The centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing according to claim 1, characterized in that: The elastic foil (42) used in the primary side radial dynamic pressure gas bearing (3), the primary side split dynamic pressure gas thrust bearing (4), the secondary side split dynamic pressure gas thrust bearing (6) and the secondary side radial dynamic pressure gas bearing (8) can be of a corrugated foil type, a metal mesh type, a bubble type, a wall-breaking protrusion type or a multi-support arm type.

4. The centrifugal air compressor rotor structure with a split type dynamic pressure gas thrust bearing according to claim 1, characterized in that: The split type dynamic pressure gas thrust bearing has a tile (43) that can be fixed to the housing by pins, or a tile (43) that can be fixed to the integral bearing seat by threads, and then the bearing seat is fixed to the housing by screws.

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