CN115045906A

CN115045906A - Integral porous tilting pad gas thrust bearing with interconnected squeeze film damper

Info

Publication number: CN115045906A
Application number: CN202210613659.9A
Authority: CN
Inventors: 冯凯; 韩少存; 张浩熙
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2022-06-01
Filing date: 2022-06-01
Publication date: 2022-09-13

Abstract

The invention relates to an interconnected squeeze film damper and an integral porous tilting pad gas thrust bearing with the same. The thrust bearing comprises a porous tile, a porous shell, a T-shaped radial fixing piece, a spring plunger, a top disc, a damper shell, a sealing ring, a chassis cover plate and a chassis, wherein the spring plunger is provided with an upper cylinder, a middle cylinder, a lower cylinder, a connecting spring, the top disc, the damper shell, the sealing ring and the chassis. When the porous pad vibrates due to axial instability and the like, the vibration is transmitted to the spring plunger through the porous shell, the middle cylinder of the plunger vibrates up and down in the damper shell, the volume of the symmetrical cavity is changed, part of damping liquid flows in the gap and the annular channel, the self-adaptive thrust disc is not centered, and part of the damping liquid flows through the effective gap to generate viscous dissipation, so that the damping of the thrust bearing is increased, and the running stability of the thrust bearing is obviously improved. The porous tilting pad gas thrust bearing is expected to cope with all misalignment of the thrust disk in ultra high speed turbomachinery.

Description

Integral porous tilting pad gas thrust bearing with interconnected squeeze film damper

Technical Field

The invention relates to an interconnected squeeze film damper.

The invention also relates to an integral porous tilting pad gas thrust bearing with the interconnected squeeze film damper and a using method thereof.

Background

In order to develop a new generation of lightweight, high power density, high power energy power equipment, the related technology of oilless bearings has been rapidly developed for over a decade. Compared with a tilting pad gas thrust bearing, the tilting pad gas radial bearing is steadily developed from a metal wire mesh structure serving as a damper to a modularized extrusion oil film structure serving as the damper to an additive manufacturing integrated tilting pad gas radial bearing with the extrusion oil film damper, and related research methods are also developed to analyze the coupling of fluid and solid in a closed space. However, the tilting pad gas thrust bearing is very slow to develop and is still in the starting phase at present.

Also as a gas thrust bearing, the bump foil gas thrust bearing adapts to all types of misalignment of a thrust disc within a reasonable power range with a simple structure, and realizes the oil-free operation of high-performance turbomachinery within a Kilowatt (KW) power range of an air cycle machine, a micro turbine and the like. However, due to the structural limitation of the bearing, the wave foil gas thrust bearing has insufficient bearing capacity, cannot adapt to the characteristics of high rotating speed and the like, and thus the application of the bearing in megawatt-level oil-free turbomachinery is hindered. High speed, heavy duty oil-free rotating machines present new challenges: 1. due to the nonlinear characteristic of the lubricating gas film, the size of the gas film is not increased in the same proportion with the size of the bearing, the larger the diameter of the bearing is, the larger the axial displacement of the edge of the thrust disc caused by the misalignment error of the thrust disc is, the thrust disc is most likely to directly generate dry friction with a tile block, and serious consequences such as tile burning are caused, so that the bearing capacity is improved, and the bearing area of the thrust bearing cannot be directly increased; 2. in megawatt-level oil-free turbo machinery, a thrust bearing needs to deal with dynamic misalignment and external warping of a thrust disc and thermal deformation of a pad and the thrust disc.

Compared with a wave foil gas thrust bearing, the integral porous tilting pad gas thrust bearing with the interconnected squeeze oil film damper has the characteristics of a tilting pad bearing, a pad can generate three degrees of freedom including vertical movement, radial tilting and circumferential tilting, damping liquid flows freely among all annular cavities to generate a self-adaptive system, the self-adaptive system has extremely high adaptive capacity to various misalignment of a thrust disc, the bearing capacity is greatly improved, and the self-adaptive system is expected to be applied to megawatt-level turbomachinery.

Disclosure of Invention

The invention aims to solve the technical problem of providing an interconnected squeeze film damper, which is part of an adaptive system of a tilting pad gas thrust bearing and can be suitable for high-performance turbomachinery.

The invention also aims to provide a monolithic porous tilting pad gas thrust bearing with the interconnected squeeze film damper.

Another object of the present invention is to provide a method for using the integral porous tilting pad gas thrust bearing.

The invention provides an integral porous tilting pad gas thrust bearing with an interconnected squeeze film damper, which comprises a porous pad block; a porous tile housing; a T-shaped radial fixing member; the spring plunger comprises an upper cylinder, a connecting spring, a middle cylinder and a lower cylinder; a top tray; a damper housing; a seal ring; a chassis cover plate; a chassis; an annular cavity is arranged among the upper cylinder, the top disc and the damper shell, a gap is arranged between the upper cylinder and the top disc, and a gap is arranged between the upper cylinder and the damper shell; an effective gap is arranged between the middle cylinder and the damper shell, symmetrical cavities are arranged between the middle cylinder and the damper shell and between the middle cylinder and the upper cylinder, and symmetrical cavities are arranged between the middle cylinder and the damper shell and between the middle cylinder and the lower cylinder; a gap is arranged between the lower cylinder and the chassis cover plate, and an annular cavity is arranged between the lower cylinder and the chassis cover plate and between the lower cylinder and the chassis.

Further, the gap between the upper cylinder and the top disk may be sealed by a flexible member connecting both the top disk and the upper cylinder, or other sealing means that allows the spring plunger to move up and down.

Further, the material of the porous tile is isostatic pressing graphite material based on graphite carbon or other porous materials.

Further, the porous tile shell is provided with an air supply hole, a gas channel shaped like a Chinese character tian, an adhesive surface, a rectangular groove and a spherical bulge.

Furthermore, the T-shaped radial fixing piece is matched with the top disc and the spring plunger to ensure three degrees of freedom of the porous tile shell, and the porous tile shell moves up and down, rotates in the radial direction and rotates in the circumferential direction.

Further, wherein the spring plunger is connected to the spherical protrusion of the porous pad housing at the upper end and connected to the bottom plate at the lower end, the connection spring is a flexible element, including but not limited to a coil spring, an S-shaped spring, etc.

Further, wherein the top disc presents a fixture mounting groove, an annular channel through which annular cavities of interconnected squeeze film dampers under different porous tiles are connected to each other.

Further, wherein the damper housing has a seal ring mounting groove.

Further, the chassis cover plate is provided with a sealing ring mounting groove and a damper shell mounting groove.

Further, wherein the bottom plate presents an annular channel, the annular cavity is a part of the annular channel, in order to allow the annular cavities to be connected to each other.

Furthermore, the annular cavity, the symmetrical cavity, the gap, the effective gap and the annular channel are filled with damping fluid.

Further, the damping fluid is a viscous fluid, such as an oil-based fluid.

Further, the damper shell and the chassis cover plate are connected through bolts; the chassis cover plate is connected with the chassis through a bolt; the top disc and the damper shell are in transition fit.

Furthermore, the sealing ring is made of rubber or other flexible materials, and plays a role in sealing damping fluid in the annular cavity and the symmetrical cavity.

Furthermore, when the rotor rotates at a high speed, the rotor bends, axial vibration possibly generated by the thrust bearing under the high-speed and heavy-load working conditions is added, so that the thrust disc generates dynamic non-centering and outward warping, the thrust disc continuously impacts the porous pad, the porous pad generates vibration and transmits the vibration to the porous pad shell and further to the spring plunger, the connecting spring can provide restoring force, the middle cylinder moves up and down, the volume of the symmetrical cavity changes, part of damping fluid flows through the gap and the annular channel to adapt to the non-centering working condition of the thrust disc, and part of damping fluid flows through the effective gap to generate energy dissipation, so that damping force opposite to the vibration direction is formed, and the operation stability of the rotor-bearing system is improved.

Furthermore, in order to relieve the situation that the damping of the thrust bearing is reduced due to overhigh frequency of dynamic misalignment of the thrust disc under the working conditions of high speed and heavy load, the influence of fluid-solid coupling is not considered, the total volume of the two symmetrical cavities is kept unchanged, and damping fluid freely flows between the annular cavities under the pads, is greatly hindered in an effective gap and is less hindered in the gap.

And further, the working gas enters the gas channel shaped like a Chinese character tian through the gas supply hole, and then enters between the porous tile and the thrust disc through the porous tile to form a lubricating gas film to support the thrust disc.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that,

the drawings in the following description are some embodiments of the invention, and it is obvious to those skilled in the art that other drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a partial, full cross-sectional view of an integral porous tilting pad gas thrust bearing of the present invention;

FIG. 2 is a top view of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 3 is a perspective view of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 4 is a perspective view of a porous pad of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 5 is a top perspective view of a porous pad housing of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 6 is a side perspective view of a porous pad housing of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 7 is a perspective view of a T-shaped radial mount of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 8 is a perspective view of the spring plunger of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 9 is a top perspective view of the top disk of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 10 is a bottom perspective view of the top disk of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 11 is a perspective view of the damper housing of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 12 is a perspective view of a seal ring of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 13 is a top plan view of the undercarriage cover plate of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 14 is a top perspective view of the undercarriage cover plate of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 15 is a bottom perspective view of the undercarriage cover plate of the integral porous tilting pad gas thrust bearing of the present invention;

FIG. 16 is a perspective view of the bottom plate of the integral porous tilting pad gas thrust bearing of the present invention;

description of reference numerals: 1-porous tile; 2-porous tile housing; 3-T-shaped radial fixing pieces; 4-a spring plunger; 5-top disk; 6-an annular cavity; 7-damper housing; 8-a symmetric cavity; 9-sealing ring; 10-a symmetric cavity; 11-a chassis cover plate; 12-an annular cavity; 13-a chassis; 14-gap; 15-clearance; 16-clearance; 17-effective gap; 18-air supply holes; 19-tian-shaped gas channel; 20-an adhesive surface; 21-rectangular groove; 22-spherical protrusions; 23-upper cylinder; 24-a connecting spring; 25-middle cylinder; 26-lower cylinder; 27-a fixture mount groove; 28-an annular channel; 29-a seal ring mounting groove; 30-a seal ring mounting groove; 31-damper housing mounting groove; 32-annular channel.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1-3, the present invention provides a monolithic porous tilting pad gas thrust bearing with an interconnected squeeze film damper, comprising a porous pad 1; a porous pad housing 2; a T-shaped radial fixing member 3; the spring plunger 4 comprises an upper cylinder 23, a connecting spring 24, a middle cylinder 25 and a lower cylinder 26; a top tray 5; a damper housing 7; a seal ring 9; a chassis cover 11; a chassis 13; an annular cavity 6 is arranged between the upper cylinder 23 and the top disc 5 and between the upper cylinder and the damper shell 7, a gap 16 is arranged between the upper cylinder and the top disc 5, and a gap 17 is arranged between the upper cylinder and the damper shell 7; an effective gap 17 is arranged between the middle cylinder 25 and the damper shell 7, a symmetrical cavity 8 is arranged between the middle cylinder and the damper shell 7 and between the middle cylinder and the upper cylinder 23, and a symmetrical cavity 10 is arranged between the middle cylinder and the damper shell 7 and between the middle cylinder and the lower cylinder 26; a gap 14 is arranged between the lower column 26 and the chassis cover plate 11, and an annular cavity 13 is arranged between the lower column and the chassis cover plate 11 and the chassis 13.

In this embodiment, in particular, the gap 16 may be sealed by a flexible element that connects both the top disk 5 and the upper cylinder 23, or other sealing means that allows the spring plunger to move up and down. The annular cavity 6, the annular cavity 12, the symmetrical cavity 8, the symmetrical cavity 10, the gap 14, the gap 15, the gap 16, the effective gap 17, the annular channel 28 and the annular channel 32 are all filled with damping fluid. The damping fluid is a viscous fluid, such as an oil-based fluid or the like. The damper shell 7 and the chassis cover plate 11 are connected through bolts; the chassis cover plate 11 and the chassis 13 are connected through bolts; the top disk 5 and the damper housing 7 are in transition fit. The spring plunger 4 is connected to the porous pad housing 2 at its upper end and to the chassis 13 at its lower end, and the connecting spring 24 is a flexible element, including but not limited to a coil spring, an S-shaped spring, etc.

As shown in fig. 4, the material of the porous segment 1 is specifically an isostatic graphite material based on graphitic carbon or other porous material.

Specifically, as shown in fig. 5 to 6, the porous tile housing 2 has an air supply hole 18, a gas passage 19 shaped like a Chinese character 'tian', an adhesive surface 20, a rectangular groove 21, and a spherical protrusion 22. The working gas enters the gas channel 19 shaped like Chinese character tian through the gas supply hole 18, and then enters between the porous tile 1 and the thrust disc through the porous tile 1 to form a lubricating gas film to support the thrust disc.

As shown in fig. 7, in particular, the T-shaped radial fixing member 3 cooperates with the top plate 5 and the spring plunger 4 to ensure three degrees of freedom of the porous pad housing 2, namely, up-and-down movement, radial rotation and circumferential rotation.

As shown in fig. 9-10, in particular, the top disk 5 presents a fixture mounting groove 27, an annular channel 28, and the annular cavities 6 of the interconnected squeeze film dampers under different porous pads 1 are connected to each other by the annular channel 28.

As shown in fig. 11, specifically, the damper housing 7 has a seal ring installation groove 29.

As shown in fig. 12, in particular, the material of the sealing ring 9 is rubber or other flexible material, which has a sealing effect on the damping fluid in the annular cavity 6, the symmetric cavity 8, and the symmetric cavity 10.

As shown in fig. 13 to 15, in particular, the floor cover 11 has a packing installation groove 30 and a damper housing installation groove 31.

As shown in fig. 16, in particular, the bottom plate 13 presents an annular channel 32, the annular cavities 12 being part of the annular channel 32, in order to allow the annular cavities 12 to be connected to each other.

In the embodiment, specifically, when the rotor rotates at a high speed, bending is generated, and axial vibration which may be generated by the thrust bearing under high-speed and heavy-load working conditions is applied, so that the thrust disc generates dynamic non-centering and outward warping, the thrust disc continuously impacts the porous pad 1, the porous pad 1 generates vibration and transmits the vibration to the porous pad housing 2, and further transmits the vibration to the spring plunger 4, the connecting spring 24 can provide restoring force, the middle cylinder 25 moves up and down, the volumes of the symmetric cavity 8 and the symmetric cavity 10 change, part of the damping fluid flows through the gap 14, the gap 15, the annular channel 28 and the annular channel 32, the self-adaption thrust disc is not centered, and part of the damping fluid flows through the effective gap 17 to generate energy dissipation, so that a damping force which is opposite to the vibration direction is formed, and the operation stability of the rotor-bearing system is improved.

Optimally, in order to relieve the situation that the damping of the thrust bearing is reduced due to overhigh frequency of dynamic misalignment of a thrust disc under the working conditions of high speed and heavy load, the influence of fluid-solid coupling is not considered, the total volume of the symmetrical cavity 8 and the symmetrical cavity 10 is kept unchanged, damping fluid freely flows between the

annular cavities

6 and 12 under each tile block, is greatly hindered in the effective gap 17, and is less hindered in the

gaps

14 and 15.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. An integral porous tilting pad gas thrust bearing with interconnected squeeze film dampers comprises a porous pad (1); a porous pad housing (2); a T-shaped radial fixing piece (3); the spring plunger (4), the spring plunger (4) includes the upper cylinder (23), connects the spring (24), the middle cylinder (25), the lower cylinder (26); a top plate (5); a damper housing (7); a seal ring (9); a chassis cover (11); a chassis (13); an annular cavity (6) is arranged between the upper cylinder (23) and the top disc (5) and between the upper cylinder and the damper shell (7), a gap (16) is arranged between the upper cylinder and the top disc (5), and a gap (15) is arranged between the upper cylinder and the damper shell (7); an effective gap (17) is arranged between the middle cylinder (25) and the damper shell (7), a symmetrical cavity (8) is arranged between the middle cylinder and the damper shell (7) and between the middle cylinder and the upper cylinder (23), and a symmetrical cavity (10) is arranged between the middle cylinder and the damper shell (7) and between the middle cylinder and the lower cylinder (26); a gap (14) is arranged between the lower column (26) and the chassis cover plate (11), and an annular cavity (12) is arranged between the lower column and the chassis cover plate (11) and the chassis (13).

2. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper of claim 1 wherein T-shaped radial mount (3) cooperates with top disk (5) and spring plunger (4) to ensure three degrees of freedom, up and down movement, radial rotation and circumferential rotation of porous pad housing (2).

3. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper of claim 1 wherein the spring plunger (4) is connected at its upper end to the knob (22) of the porous pad housing (2) and at its lower end to the chassis (13), the connecting spring (24) being a flexible element including but not limited to a coil spring, S-spring, etc.

4. A monolithic porous tilting pad gas thrust bearing with interconnected squeeze film dampers according to claim 1 wherein the top disc (5) presents fixture mounting slots (27), annular channels (28), and the annular cavities (6) of the interconnected squeeze film dampers under different porous pads (1) are connected to each other by the annular channels (28).

5. A monolithic porous tilting pad gas thrust bearing with interconnected squeeze film damper according to claim 1 wherein the damper housing (7) presents a seal ring mounting groove (29).

6. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper of claim 1 wherein the undercarriage cover plate (11) presents a seal ring mounting groove (30), a damper housing mounting groove (31).

7. A monolithic porous tilting pad gas thrust bearing with interconnected squeeze film damper according to claim 1 wherein the bottom plate (13) presents an annular channel (32) and the annular cavity (12) is part of the annular channel (32) in order to connect the annular cavities (12) to each other.

8. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper of claim 1 wherein the annular cavity (6), annular cavity (12), symmetric cavity (8), symmetric cavity (10), gap (14), gap (15), gap (16), effective gap (17), annular channel (28), and annular channel (32) are filled with damping fluid.

9. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper of claim 1 wherein damper housing (7) and undercarriage cover plate (11) are bolted; the chassis cover plate (11) is connected with the chassis (13) through bolts; the top disc (5) and the damper shell (7) are in transition fit.

10. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper as claimed in claim 1, wherein the material of the seal ring (9) is rubber or other flexible material, which seals the damping fluid in the annular cavity (6), the symmetrical cavity (8) and the symmetrical cavity (10).

11. The integral porous tilting pad gas thrust bearing with interconnected squeeze film damper as claimed in claim 1, wherein the rotor is bent when rotating at high speed, and the axial vibration of the thrust bearing, which may be generated under high speed and heavy load working conditions, causes the thrust disk to generate dynamic non-centering and non-outward warping, the thrust disk continuously impacts the porous pad (1), the porous pad (1) generates vibration and transmits the vibration to the porous pad housing (2) and further to the spring plunger (4), the connecting spring (24) provides restoring force, the middle cylinder (25) moves up and down, the volumes of the symmetric cavity (8) and the symmetric cavity (10) change, part of the damping fluid flows through the gap (14), the gap (15), the annular channel (28) and the annular channel (32), and the self-adaptive thrust disk non-centering working condition is adapted, part of damping fluid flows through the effective gap (17) to generate energy dissipation, so that a damping force opposite to the vibration direction is formed, and the operation stability of the rotor-bearing system is improved.

12. The operation of the thrust bearing in response to the misalignment of the thrust disk according to claim 11, wherein the free flow between the annular cavities (6) and between the annular cavities (12) under the respective pads of the damping fluid is greatly impeded in the effective gap (17) and less impeded in the gaps (14) and (15).

13. A thrust bearing to cope with the operation of a thrust disc misalignment condition according to claim 11 wherein the gap (16) may be sealed by a flexible element connecting both the top disc (5) and the upper cylinder (23) or other sealing means allowing the spring plunger to move up and down.