CN221097204U - Assembled dynamic pressure gas thrust bearing and rotor system of high-speed centrifugal air compressor - Google Patents

Abstract

The utility model discloses an assembled dynamic pressure gas thrust bearing and a rotor system of a high-speed centrifugal air compressor, wherein the bearing comprises pins, pads, elastic foil and flat foil; the tile is fan-shaped, and the surface of the tile is provided with pin holes; the elastic foil and the flat foil are stacked and connected with the tile block through the welding duty section; the tiles are uniformly distributed on the shell and fixed by pins; in the installed device, the tile, the elastic foil and the flat foil are sequentially overlapped and arranged. According to the assembled dynamic pressure gas thrust bearing and the rotor system of the high-speed centrifugal air compressor, the bearing adopts the split assembled structure, the problem that the bearing positioned on the inner side of the thrust disc is difficult to replace after the thrust disc is hot-assembled can be effectively solved in the rotor system of the high-speed centrifugal air compressor, the structure is more flexible, the processing and the assembly are convenient, the bearing bush is fixed by adopting the pin to replace the bearing seat, on one hand, the heat dissipation of the bearing is facilitated, on the other hand, the positioning of the bearing bush is facilitated, and the replacement cost after the foil is worn is reduced.

Description

Assembled dynamic pressure gas thrust bearing and rotor system of high-speed centrifugal air compressor

Technical Field

The utility model relates to the field of gas bearings and high-speed rotating machinery, in particular to a novel dynamic pressure gas thrust bearing and a rotor system of a high-speed centrifugal air compressor.

Background

Current research shows that foil hydrodynamic gas bearings exhibit good characteristics in terms of stability, reliability and high-speed impact resistance. Therefore, it is widely applied to various high-speed rotating machinery fields, such as high-speed turbojet engines, high-speed turboexpanders, high-speed oilless centrifugal air compressors of fuel cell automobiles, distributed energy micro gas turbines and the like. This technology has a broad future development prospect. However, accurate conclusion analysis and model building remain challenges for foil hydrodynamic gas bearings, with hysteresis between theoretical analysis and experimental progression. Therefore, foil dynamic pressure gas bearings currently used in high-speed rotating machinery lack unified standards and serialization guidelines, and different researchers adopt methods of respective matching designs, so that the structures of the foil dynamic pressure gas bearings are continuously changed.

In the existing research, the method for manufacturing the foil dynamic pressure gas thrust bearing mainly adopts a centralized and integral mode. The centralized structure mainly divides the elastic foil and the flat foil into four, six or eight pieces and directly welds them on the bearing seat. In the manufacturing process, precise matching is required to avoid misalignment and to precisely position each foil unit on the bearing support, while also ensuring welding uniformity and reliability. This process is very complex and if there is a deviation in the positioning or welding of one of the foils, it will lead to rejection of the entire bearing pair. The integral structure is formed by integrally stamping the foil, is fixed on the shell, does not need a bearing seat as a carrier, has simple process and higher precision, but is difficult to replace and has high cost.

In order to ensure that the whole system is stable when rotating at a high speed, a way of hot charging the thrust disc and the main shaft or a way of directly processing the thrust disc and the main shaft into a whole is adopted. The hot loading method is that the inner diameter of the thrust disc is slightly smaller than the diameter of the main shaft, the thrust disc is heated and expanded, the thrust disc is convenient to install on the main shaft, in the cooling process, the inner diameter of the thrust disc is uniformly contracted and is in interference fit on the main shaft, the unbalanced mass of the thrust disc and the main shaft during assembly is greatly reduced, and the mass center is located at the geometric center as much as possible. The interference fit structure or the integral structure after the thrust disc and the main shaft are hot-assembled effectively reduces the eccentricity of the system during rotation, other parts are not required to fix the thrust disc, the structure is more compact, the unbalancing property of the system during rotation is reduced, and the abrasion of the bearing is slowed down. After the thrust disc and the main shaft adopt a hot-set structure or an integrated structure, the thrust disc and the main shaft can be regarded as a non-detachable structure, and the bearing used by the centralized and integrated structure can cause the problem that the bearing pair between the thrust disc and the rotor sheath is difficult to replace and detach or can not be replaced.

Therefore, the invention discloses an assembled dynamic pressure gas thrust bearing and a rotor system of a high-speed centrifugal air compressor, and the problems that after a thrust disc is hot-packed, a foil is damaged and is difficult to replace, the bearing capacity is uneven and the heat dissipation is slow are effectively solved by assembling the shoe to form a single detachable thrust bearing. The innovation reduces the technological difficulty of the foil dynamic pressure gas thrust bearing and is convenient for standardized and serial production and flow production.

Disclosure of utility model

The utility model aims to provide an assembled dynamic pressure gas thrust bearing and a rotor system of a high-speed centrifugal air compressor, and a modularized assembly structure is introduced by improving the processing and mounting modes and the process of the bearing. Compared with the traditional integral welding structure, each part of the bearing is easier to detach and replace, the process flow is simplified, and meanwhile, the requirement on precision is reduced. In addition, the distribution of the foil is more uniform, and the uniformity of the bearing capacity is improved. The structure that the tile block is in direct contact with the shell is adopted in the design, so that the heat dissipation effect of the foil bearing is further improved.

In order to achieve the above purpose, the present utility model proposes the following technical scheme: an assembled dynamic pressure gas thrust bearing and a rotor system of a high-speed centrifugal air compressor are characterized in that the bearing comprises a tile, a pin, an elastic foil and a flat foil. The tile is fan-shaped, and the surface of the tile is provided with a pin through hole; the elastic foil and the flat foil are fan-shaped and are composed of a straight section of a working surface and a duty section for welding installation, and the elastic foil and the flat foil are stacked and connected with the tile through the welding duty section; the tiles are uniformly distributed on the shell and fixed by pins; in the installed device, the tile, the elastic foil and the flat foil are sequentially overlapped and arranged.

The rotor system of the high-speed centrifugal air compressor comprises a main shaft, a primary impeller, the assembled dynamic pressure gas thrust bearing, a thrust disc, a magnet, a rotor sheath and a secondary impeller, wherein all parts are sequentially distributed on the main shaft according to the sequence. The thrust disc and the main shaft are assembled in a hot-loading mode to form an interference fit structure, or the thrust disc and the main shaft are machined into a whole. The assembled dynamic pressure gas thrust bearings are distributed on two sides of the thrust disc, and are axially supported by the rotor system together with the thrust disc, and the gas bearings between the thrust disc and the primary impeller can also be of an integral structure.

Further, the elastic foil can be of a corrugated foil type, a wire mesh type, a bubbling type, a wall breaking bulge type or a multi-support arm type.

Furthermore, the surface of the tile is provided with three pin holes, and the middle hole can also be a screw hole; the outer cylindrical surface of the tile is provided with one or more pin holes, and the two bottom surfaces of the tile are parallel.

Further, the inner diameters of the elastic foil and the flat foil are equal to the inner diameter of the pad; after being welded on the pad, the edge side surface of the elastic foil duty section and the edge side surface of the flat foil duty section are overlapped with one side surface of the pad, and the inner ring of the elastic foil and the inner ring of the flat foil are overlapped with the inner cylindrical surface of the pad; the outside diameter of the pad is larger than the outside diameter of the foil to reserve pin holes.

Further, the tiles welded with the foil sheets are uniformly arranged on the shell through pins; when in installation, the inner cylindrical surface of the tile is kept coaxial with the shell; the number of the sector tiles which can be distributed on the shell is three to eight.

Further, the tiles are evenly distributed on the housing. The gaps are determined by pins between the tiles, and the gaps between the tiles are kept consistent.

Drawings

Fig. 1 is an exploded view of parts for an assembled dynamic pressure gas thrust bearing.

Fig. 2 is a schematic diagram of a pad, spring foil and flat foil connection structure for an assembled hydrodynamic gas thrust bearing.

FIG. 3 is a schematic view of the mounting and positioning of the shoe and housing of the assembled hydrodynamic gas thrust bearing with the positioning shaft and spacer bars.

Fig. 4 is a schematic structural view of a rotor system of a high-speed centrifugal air compressor.

In the upper diagram, 1 is a pin, 2 is a tile, 3 is an elastic foil, 4 is a flat foil, 5 is a positioning parting bead, 6 is a positioning shaft, 7 is a main shaft, 8 is a primary impeller, 9 is an assembled dynamic pressure gas thrust bearing, 10 is a thrust disc, 11 is a magnet and rotor sheath, and 12 is a secondary impeller.

Detailed Description

In order to better understand the objects, technical solutions and advantages of the present utility model, the technical solutions in the embodiments of the present utility model will be described below with reference to the accompanying drawings in the embodiments of the present utility model.

As shown in fig. 1, the utility model provides an assembled foil dynamic pressure gas thrust bearing, which comprises a pin 1, a tile 2, an elastic foil 3 and a flat foil 4, wherein the tile 2 is assembled and fastened through the pin 1 to realize axial and radial positioning; the tiles 2 are uniformly distributed on the shell, and the elastic foil 3 and the flat foil 4 are overlapped and welded on the sector tiles 2 at one time.

As shown in fig. 2, the elastic foil 3 and the flat foil 4 are welded on the (21) surface of the pad by overlapping the duty segment 31 and the duty segment 41; during welding, the edge sides 32 and 42 of the duty section of the foil are overlapped with the side 22 of the tile, the inner ring 33 of the elastic foil and the inner ring 43 of the flat foil are overlapped with the inner cylindrical surface 23 of the tile, and the edge side of the flat section of the foil is overlapped with the other side of the tile or has a certain parallel distance. The tile 2 is a component which is arranged on the shell and used for modularly installing the elastic foil 3 and the flat foil 4, when the tile 2, the elastic foil 3 and the flat foil 4 are in welding and positioning problems or a certain foil unit is damaged in the using process, the foils 3 and 4 which are welded and installed in the same series and the tile 2 are independently replaced in time, so that the effects of simplifying the processing technology, improving the processing efficiency and reducing the defective rate and the processing and assembling difficulty are achieved; the flexible foil working section 32 and the flat foil working section 42 form a wedge-shaped space with the shaft shoulder for forming a dynamic pressure air film to bear axial force and axially support and position the rotor.

When a gap exists between the tiles 2, the positioning shaft 6 and the positioning parting bead 5 are adopted for installation. As shown in fig. 3, two tiles 2 are installed and fixed by using pins 1, and then a positioning shaft 6 is placed on an inner cylindrical surface 23 of each tile by using gravity, and a positioning shaft cylindrical surface 61 is attached to the inner cylindrical surface 23 of each tile. Positioning parting strips 5 are placed on the side surfaces 22 where two tiles are attached, the width of each parting strip is consistent with the design gap between the tiles, so that the side surfaces 51 of the positioning parting strips are tightly attached to the side surfaces 22 of the tiles, then other tiles are sequentially installed, the positions of the tiles are properly adjusted after all the tiles are installed, the uniformity of the circumferential distribution of the tiles is ensured, and after the adjustment is proper, the positioning shaft 6 and the positioning parting strips 5 are taken out.

As shown in fig. 4, in the rotor system of the high-speed centrifugal air compressor, when the thrust disc 10 is installed, the thrust disc needs to be heated and expanded to be in interference fit with the main shaft 7, and after the assembled dynamic pressure gas thrust bearing 9 is worn in operation, the worn parts can be independently disassembled for replacement, so that the replacement parts can be removed without the need of re-disassembling the thrust disc like an integral bearing.

Claims (6)

1. The rotor system of the high-speed centrifugal air compressor comprises a main shaft (7), a primary impeller (8), an assembled dynamic pressure gas thrust bearing (9), a thrust disc (10), a magnet, a rotor sheath (11) and a secondary impeller (12), wherein all parts are sequentially distributed on the main shaft (7) according to the sequence; the thrust disc (10) and the main shaft (7) are assembled in a hot-loading mode to form an interference fit structure, or the thrust disc (10) and the main shaft (7) are directly processed into a whole; the assembled dynamic pressure gas thrust bearings are distributed on two sides of the thrust disc (10), and form an axial support of a rotor system together with the thrust disc (10), and the gas bearings between the thrust disc (10) and the primary impeller (8) adopt an integral structure.

2. The assembled dynamic pressure gas thrust bearing and high-speed centrifugal air compressor rotor system according to claim 1, wherein the elastic foil (3) is any one of a corrugated foil type, a wire mesh type, a bubbling type, a broken wall bulge type, and a multi-support arm type.

3. The assembled dynamic pressure gas thrust bearing and high speed centrifugal air compressor rotor system of claim 1, wherein the tile surface is provided with three pin holes, the middle hole is a screw hole; the outer cylindrical surface of the tile is provided with one or more pin holes, and the two bottom surfaces of the tile are parallel.

4. An assembled dynamic pressure gas thrust bearing and high speed centrifugal air compressor rotor system according to claim 2, characterized in that the inner diameter of the elastic foil (3) and the flat foil (4) are both equal to the inner diameter of the shoe (2); after being welded on the pad, the edge side surface (32) of the duty section of the elastic foil and the edge side surface (42) of the duty section of the flat foil are overlapped with one side surface (22) of the pad, and the inner ring (33) of the elastic foil and the inner ring (43) of the flat foil are overlapped with the inner cylindrical surface (23) of the pad; the outside diameter of the pad is larger than the outside diameter of the foil to reserve pin holes.

5. An assembled dynamic pressure gas thrust bearing and high speed centrifugal air compressor rotor system according to any of claims 1-4, characterized in that the foil welded tiles (2) are mounted evenly on the housing by pins (1); when in installation, the inner cylindrical surface (23) of the tile is coaxial with the shell; the number of the sector tiles (2) which can be distributed on the shell is three to eight.

6. An assembled dynamic pressure gas thrust bearing and high speed centrifugal air compressor rotor system as claimed in claim 5, wherein the tiles (2) are uniformly distributed on the housing, the gaps between the tiles are determined by pins (1), and the gaps between the tiles are kept uniform.