Dynamic and static pressure hybrid thrust bearing structure

Abstract

The utility model relates to a dynamic and static pressure mixed thrust bearing structure which comprises a back plate, the back plate is of a hollow cylinder structure, a plurality of fan-shaped bosses are evenly distributed on the front face of the back plate at intervals in the circumferential direction, a gasket and a bottom foil are arranged between every two adjacent fan-shaped bosses, fan-shaped flat foils are arranged on the gaskets and the bottom foils, and pressure equalizing grooves are formed in the fan-shaped bosses. The pressure equalizing groove is an arc-shaped groove, air outlet holes are formed in the pressure equalizing groove, the air outlet holes are connected with air inlet holes through air supply flow channels, the air supply flow channels are located in the back plate, and the air inlet holes are located in the outer wall of the back plate. The dynamic and static pressure hybrid bearing provided by the utility model is of a multi-tile structure, and the flexible foils and the steps with the air inlet holes are distributed in a staggered manner. The working back pressure of the bearing can be improved through external high-pressure air supply of the air inlet holes, the dynamic pressure effect is improved, abrasion of the bearing during starting and stopping is avoided, and therefore the bearing capacity and rigidity of the bearing are improved.

Description

Technical Field

[0001] The utility model relates to a structure of a hybrid hydrostatic and hydrodynamic thrust bearing. Background Art

[0002] As the core supporting component of a high-speed rotor system, gas bearings are widely used in the fields of aerospace, high-speed turbines, cryogenic technology, air circulation, cryogenic refrigeration, micro gas turbines, etc., and have very good application prospects.

[0003] Gas bearings are usually divided into hydrostatic gas bearings and hydrodynamic gas bearings.

[0004] Hydrostatic gas bearings use an external gas source to supply gas to generate a high-pressure gas film to support the rotor, and have the advantages of large bearing capacity, long service life, and high rotational accuracy; but at the same time, hydrostatic bearings often require an independent high-pressure gas supply system, which increases the complexity of the system, and hydrostatic bearings have a large gas consumption, high cost, and poor stability under ultra-high-speed conditions.

[0005] Hydrodynamic gas bearings use the relative movement of the bearing mating surfaces to compress the lubricating gas in the viscous action in a wedge-shaped space, so as to generate a high-pressure load in the gap. The foil bearing is a typical hydrodynamic gas bearing, usually composed of a flat foil and an elastic support structure. The structural damping and frictional damping generated by its elastic deformation can effectively dissipate the unstable whirling energy of the bearing rotor system, thereby improving the high-speed stability and impact resistance of the bearing rotor system. In addition, the elastic surface of the foil bearing can reduce the requirements for the machining and assembly accuracy of the bearing, and has good adaptability and economy; but hydrodynamic gas bearings have the disadvantages of large frictional torque, insufficient bearing capacity, and low stiffness during start-up and shutdown.

[0006] The Chinese patent application with the publication number of "CN112762094A" and the invention name of "A hybrid hydrostatic and hydrodynamic gas thrust foil bearing and a hybrid hydrostatic and hydrodynamic device" provides a hybrid hydrostatic and hydrodynamic gas thrust foil bearing, which opens air intake holes on the top foil, and the air supply pipe passes through the bottom foil from the bottom plate and is connected to the air intake holes. However, due to the elastic surface of the foil, it is difficult to ensure gas supply for the air supply pipe. Summary of the Invention

[0007] The utility model provides a structure of a hybrid hydrostatic and hydrodynamic thrust bearing, in which flexible foils and steps with air intake holes are staggered. The external high-pressure gas supply through the air intake holes can increase the back pressure of the bearing operation, enhance the hydrodynamic effect, avoid the wear during the start-up and shutdown of the bearing, thereby improving the bearing capacity and stiffness of the bearing; at the same time, the flexible foils can provide a certain amount of damping for the bearing, absorb the energy of the rotor whirling, enhance the bearing stability, and reduce the gas consumption during the bearing operation.

[0008] The technical solution of the present utility model to solve the above problems is: a hybrid hydrostatic and hydrodynamic thrust bearing structure, which is characterized in that:

[0009] It includes a back plate, the back plate is a hollow cylindrical structure, and several sector-shaped convex platforms are evenly distributed at intervals on the front surface of the back plate. A gasket and a bottom foil are arranged between two adjacent sector-shaped convex platforms, and a sector-shaped flat foil is arranged on the gasket and the bottom foil. The sector-shaped convex platform is provided with a pressure equalizing groove, the pressure equalizing groove is an arc-shaped groove, and an air outlet hole is arranged on the pressure equalizing groove. The air outlet hole is connected to an air inlet hole through an air supply channel, the air supply channel is located inside the back plate, and the air inlet hole is located on the outer wall of the back plate. The function of the pressure equalizing groove is to make the pressure distribution in the lubrication gap more uniform after the high-pressure gas flows in from the air outlet hole, reduce the situation of too high or too low local pressure, and can improve the bearing capacity of the bearing and suppress the micro-vibration of the bearing.

[0010] Further, at the root of one side of the sector-shaped convex platform, a positioning slit is radially opened along the back plate, and one end of the sector-shaped flat foil and the bottom foil is flush with the positioning slit.

[0011] Further, both the gasket and the bottom foil are sector-shaped structures. One gasket and one bottom foil correspond to each sector-shaped convex platform below, and the sector-shaped convex platform just covers the corresponding gasket and bottom foil below.

[0012] Further, one side of the gasket is in contact with one side of the bottom foil.

[0013] Further, the fixed ends of the gasket and the bottom foil are directly fixed on the back plate by welding or riveting respectively, and the fixed end of the sector-shaped flat foil is directly fixed on the gasket by welding or riveting.

[0014] Advantages of the present utility model:

[0015] The hybrid hydrostatic and hydrodynamic bearing proposed by the present utility model is a multi-pad structure, and the flexible foil and the stepped part with air inlet holes are staggered. The external high-pressure air supply through the air inlet hole can increase the back pressure during the operation of the bearing, enhance the hydrodynamic effect, avoid the wear during the start and stop of the bearing, thereby improving the bearing capacity and stiffness of the bearing; at the same time, the flexible foil can provide a certain damping for the bearing, absorb the energy of the rotor whirl, improve the bearing stability, and reduce the air consumption during the operation of the bearing. Brief Description of the Drawings

[0016] Figure 1 is an exploded view of the overall structure of the hybrid hydrostatic and hydrodynamic thrust bearing provided by the present utility model;

[0017] Figure 2 is a top view of the hybrid hydrostatic and hydrodynamic thrust bearing provided by the present utility model;

[0018] Figure 3 is another perspective view of the hybrid hydrostatic and hydrodynamic thrust bearing provided by the present utility model;

[0019] Figure 4 are the front view and axonometric view of the back plate of the hybrid hydrostatic and hydrodynamic thrust bearing provided by the present utility model;

[0020] Figure 5 is Figure 4 the enlarged view of part A in

[0021] Figure 6 is another perspective view of the hybrid hydrostatic and hydrodynamic thrust bearing provided by the present utility model;

[0022] Figure 7 is Figure 4 the enlarged view of part B in

[0023] In the figure: 1 - flat foil; 2 - gasket; 3 - bottom foil; 4 - back plate; 41 - boss; 42 - air outlet hole; 43 - air inlet hole; 44 - positioning slit. Specific embodiments

[0024] To make the purpose, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present utility model. Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model.

[0025] See Figures 1-7 , a hybrid hydrostatic and hydrodynamic thrust bearing structure, including a back plate 4. The back plate 4 is a hollow cylindrical structure. A plurality of sector-shaped bosses 41 are evenly distributed at intervals on the front surface of the back plate 4. A gasket 2 and a bottom foil 3 are provided between two adjacent sector-shaped bosses 41. A sector-shaped flat foil 1 is arranged on the gasket 2 and the bottom foil 3. One gasket 2 and one bottom foil 3 correspond to one sector-shaped flat foil 1 below. An equalizing groove is provided on the sector-shaped boss 41. The equalizing groove is an arc-shaped groove. An air outlet hole 42 is provided on the equalizing groove. The air outlet hole 42 is connected to an air inlet hole 43 through an air supply channel. The air supply channel is located inside the back plate 4, and the air inlet hole 43 is located on the outer wall of the back plate 4.

[0026] See Figure 5 , the arc-shaped equalizing groove on the boss 41 can make the pressure distribution in the lubrication gap more uniform after the high-pressure gas flows in from the air outlet hole 42, reduce the situation of too high or too low local pressure, and can improve the load-bearing capacity of the bearing and suppress the micro-vibration of the bearing.

[0027] Specifically, refer to 2, Figure 3 and Figure 7 , between two adjacent sector-shaped bosses 41, at the root on one side of the sector-shaped boss 41, a positioning slit 44 is radially formed along the back plate 4. The positioning slit 44 penetrates through the back plate 4. The positioning slit 44 increases the heat dissipation channels inside the bearing and enhances the heat dissipation effect of the bearing. One end of the sector-shaped flat foil 1 and the bottom foil 3 is flush with the positioning slit 44. Both the gasket 2 and the bottom foil 3 are of sector-shaped structures, and the sector-shaped boss 41 exactly covers the corresponding gasket 2 and bottom foil 3 below.

[0028] Specifically, refer to 2, Figure 3 and Figure 7 , the fixed ends of the gasket 2 and the bottom foil 3 are directly fixed on the back plate 4 by welding or riveting respectively, and the fixed end of the sector-shaped flat foil 1 is directly fixed on the gasket 2 by welding or riveting.

[0029] When the hybrid hydrodynamic and hydrostatic thrust bearing is working, the external high-pressure gas flows into the back plate from the air inlet hole 43 and flows into the lubrication gap between the bearing and the rotor from the air outlet hole 42, which can increase the pressure in the air film gap and enhance the hydrodynamic effect, thereby improving the bearing capacity and stiffness of the bearing and avoiding the wear of the bearing during start-up and shutdown; at the same time, the flexible foil structure including the flat foil 1 and the bottom foil 3 can provide a certain damping for the bearing, absorb the whirling energy during the operation of the rotor, and improve the system stability.

[0030] The above are only the embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied to other related system fields, shall be equally included in the protection scope of the present invention.

Claims

1. A hybrid hydrostatic and hydrodynamic thrust bearing structure, characterized in that: It includes a back plate (4), the back plate (4) is a hollow cylindrical structure, and a plurality of sector-shaped bosses (41) are evenly distributed at intervals in the circumferential direction on the front surface of the back plate (4). A gasket (2) and a bottom foil (3) are provided between two adjacent sector-shaped bosses (41). A sector-shaped flat foil (1) is arranged on the gasket (2) and the bottom foil (3). An equalizing groove is provided on the sector-shaped boss (41), the equalizing groove is an arc-shaped groove, and an air outlet hole (42) is provided on the equalizing groove. The air outlet hole (42) is connected to an air inlet hole (43) through an air supply channel, the air supply channel is located inside the back plate (4), and the air inlet hole (43) is located on the outer wall of the back plate (4).

2. The hybrid hydrostatic and hydrodynamic thrust bearing structure according to claim 1, characterized in that: At the root of one side of the sector-shaped boss (41), a positioning slit (44) is radially opened along the back plate (4), and one end of the sector-shaped flat foil (1) and the bottom foil (3) is flush with the positioning slit (44).

3. The hybrid hydrostatic and hydrodynamic thrust bearing structure according to claim 1, characterized in that: Both the gasket (2) and the bottom foil (3) are sector-shaped structures. One gasket (2) and one bottom foil (3) correspond to each sector-shaped boss (41) below, and the sector-shaped boss (41) just covers the corresponding gasket (2) and bottom foil (3) below.

4. The hybrid hydrostatic and hydrodynamic thrust bearing structure according to claim 1, characterized in that: One side of the gasket (2) is in contact with one side of the bottom foil (3).

5. The hybrid hydrostatic and hydrodynamic thrust bearing structure according to claim 2, characterized in that: The fixed ends of the gasket (2) and the bottom foil (3) are directly fixed on the back plate (4) by welding or riveting respectively, and the fixed end of the sector-shaped flat foil (1) is directly fixed on the gasket (2) by welding or riveting.

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