Intelligent Tilting Pad Hydrostatic Gas Bearing and Its Dynamic Adjustment Method for Stiffness and Damping Characteristics

Abstract

Intelligent tilting pad hydrostatic gas bearing, comprising a bearing housing, a tilting pad assembly, a porous graphite block and a corrugated air duct. The tilting pad assemblies are evenly arranged along the circumferential direction of the bearing housing. The tilting pad assembly includes a support pad block fitting and positioning on the inner wall of the bearing housing, a tilting pad block located radially inside the support pad block, a flexible damping member connecting the support pad block and the tilting pad block along the radial direction, and a piezoelectric ceramic induction adjustment member that forms a radial telescopic deformation controlled by an external control system. The porous graphite block is installed at the inner end of the tilting pad block. The piezoelectric ceramic induction adjustment member is clamped between the tilting pad block and the support pad block and is signal-transmission connected to the external control system. The corrugated air duct passes through the bearing housing, the support pad block and the piezoelectric ceramic induction adjustment member along the radial direction and is communicated with the tilting pad block. The present invention realizes the dynamic adjustment of the stiffness and damping characteristics of the bearing, forming intelligent control of the bearing. The present invention also provides a method for dynamically adjusting the stiffness and damping characteristics of an intelligent tilting pad hydrostatic gas bearing.

Description

Technical Field

[0001] The present invention relates to an intelligent tilting pad hydrostatic gas bearing and a method for dynamically adjusting its stiffness and damping characteristics, belonging to the technical field of hydrostatic gas bearings. Background Technique

[0002] A porous tilting pad gas bearing has a porous material pasted on the metal surface of the tilting pad. The porous tilting pad gas bearing can combine the advantages of a porous hydrostatic gas bearing with the stability of a tilting pad bearing, and has good characteristics in terms of load capacity, damping, and stiffness. It also has the characteristics of pollution-free, low wear, and high speed, so it is increasingly used in high-speed rotating machinery. For a porous tilting pad gas bearing, an externally pressurized gas enters the bearing base through an external air inlet, flows out from the porous material, and forms an air film between the bearing and the rotor to support the rotor system, realizing non-contact suspension between the bearing and the rotor. The porous material is a gas restrictor for the hydrostatic bearing. Since the gas leakage rate of the air film layer increases during high-speed rotation of the rotor, the damping of the bearing decreases, and subsynchronous vibration is likely to occur during high-speed operation, resulting in unstable operation of the bearing, which will lead to poor operating stability of the entire bearing-rotor system.

[0003] To effectively improve the damping of the bearing, an effective measure is to install a squeeze film damper on the bearing. However, there will still be a problem of internal hydraulic oil leakage during the operation of the squeeze film damper, which will cause environmental pollution. To effectively improve the damping of the bearing and avoid environmental pollution, the patent document CN114483789A, "A Porous Tilting Pad Gas Based on an Electromagnetic Damper", discloses a porous tilting pad gas bearing based on an electromagnetic damper, which mainly consists of a bearing base, an electromagnetic damper, tilting pads, and a porous material. The tilting pads and the bearing base form a concentric annular structure. An electromagnetic damper is installed between the bearing base and the tilting pads. An external air inlet is provided on the outer end face of the tilting pads along the axial direction. A pressure equalizing groove structure is provided on the side of the tilting pads away from the bearing base. The porous material is installed in the pressure equalizing groove, and a porous material air supply hole communicating with the external air inlet is provided at the bottom of the pressure equalizing groove. In this solution, the overall damping of the bearing can be improved through the setting of the electromagnetic damper. However, the tilting pad hydrostatic gas bearing still has the following defects:

[0004] 1. Due to the complex and variable speed of the rotor, the vibration frequency and vibration amplitude of the bearing are unstable, but the stiffness and damping characteristics of the bearing cannot be adjusted adaptively, resulting in a narrow speed range for the stable operation of the bearing-rotor system, and the variable speed will cause a decrease in stability.

[0005] 2. The intake pipe is connected to the side of the tilting pad structure, and the ventilation efficiency is not high, which is prone to air leakage. Moreover, the air supply holes are on the side of the pad, which will limit the free rotation of the pad to a certain extent.

[0006] 3. Since the bearing adopts a segmented tilting pad bearing structure, during the installation process of the bearing, the radial position of the tilting pad structure cannot be adjusted according to the size and load-bearing requirements of the rotor. Summary of the Invention

[0007] The intelligent tilting pad hydrostatic gas bearing provided by the present invention realizes the dynamic adjustment of the stiffness and damping characteristics of the bearing, thereby changing the critical frequency of the bearing-rotor system, broadening the speed range for stable operation of the bearing-rotor system, improving the load-bearing capacity of the bearing, using the signal transmission connection between the piezoelectric ceramic induction regulator and the external control system to form intelligent control of the bearing, and improving the stability of the bearing-rotor system with complex and variable rotor speeds. The present invention also provides a method for dynamically adjusting the stiffness and damping characteristics of an intelligent tilting pad hydrostatic gas bearing.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The intelligent tilting pad hydrostatic gas bearing includes a bearing housing, a tilting pad assembly installed in the bearing housing, a porous graphite block installed on the tilting pad assembly and having an arc shape, and a corrugated air duct for introducing gas onto the porous graphite block. The tilting pad assemblies are evenly arranged along the circumferential direction of the bearing housing. It is characterized in that: the tilting pad assembly includes a support pad block fitting and positioning on the inner wall of the bearing housing, a tilting pad block located radially inside the support pad block, a flexible damping member connecting the support pad block and the tilting pad block radially, and a piezoelectric ceramic induction regulator controlled by an external control system to form radial telescopic deformation. The porous graphite block is installed at the inner end of the tilting pad block. The piezoelectric ceramic induction regulator is clamped between the tilting pad block and the support pad block and is signal-transmission connected to the external control system. The corrugated air duct passes through the bearing housing, the support pad block, and the piezoelectric ceramic induction regulator radially and is communicated with the tilting pad block.

[0010] Preferably, a gas guiding groove corresponding to the porous graphite block is opened on the inner end surface of the tilting pad block. The gas guiding groove is communicated with the corrugated air duct. The inner wall of the gas guiding groove has a raised card slot arranged axially. The porous graphite block has a raised card strip that is snap-fitted with the raised card slot. The raised card strip snaps into the raised card slot to embed the porous graphite block into the gas guiding groove, and a circular arc-shaped gas storage cavity is formed on the back of the porous graphite block.

[0011] Preferably, the raised card slot is a strip-shaped groove with a T-shaped cross-section, the raised card strip is a strip with a T-shaped cross-section, a side opening is opened on one side of the gas guiding groove, the raised card strip extends into the raised card slot from the side opening, a sealing gasket and a sealing gasket pressing plate are padded on the side opening, the sealing gasket pressing plate is fixed to the tilting pad block by bolts and presses the sealing gasket, and the sealing gasket presses the circular arc-shaped side surface of the porous graphite block to axially press the porous graphite block in the gas guiding groove.

[0012] Preferably, an air guide through-hole communicating the corrugated air guide pipe and the air guide groove is formed in the tilting pad, a butt end ring communicating with the air guide through-hole is arranged on the outer end surface of the tilting pad, and the inner end of the corrugated guide pipe is sleeved on the butt end ring.

[0013] Preferably, the flexible damping members are symmetrically arranged on both sides of the piezoelectric ceramic induction adjusting member. T-shaped connection grooves for connecting the flexible damping members are formed on the inner end surface of the support pad and the outer end surface of the tilting pad. T-shaped connection ends corresponding to the T-shaped connection grooves are arranged at both ends of the flexible damping member. The flexible damping member is a stainless steel sheet with a wavy shape along the radial direction.

[0014] Preferably, the inner end surface of the support pad and the outer end surface of the tilting pad are both flat surfaces. The piezoelectric ceramic induction adjusting member is clamped between the inner end surface of the support pad and the outer end surface of the tilting pad, and includes a piezoelectric ceramic block that expands and contracts radially along with the signal control of an external system and a PVDF sensor for sensing the vibration signal of the bearing. The piezoelectric ceramic block is sleeved outside the corrugated air guide pipe and fits against the inner end surface of the support pad. The PVDF sensor is clamped between the piezoelectric ceramic block and the tilting pad. The connecting wires of the piezoelectric ceramic block and the PVDF sensor respectively pass through the bearing housing and are connected to an external control system. The PVDF sensor is in the shape of a thin sheet and the number is two. The two PVDF sensors are symmetrically arranged on both sides of the corrugated air guide pipe.

[0015] Preferably, the bearing housing includes an annular base and a base cover plate covering the end surface of the annular base. The tilting pad assembly is installed in the cavity formed by the annular base and the base cover plate and is connected to the annular base.

[0016] Preferably, the support pad is provided with a support pad through-hole for the corrugated air guide pipe to pass through. A tile butt pipe communicating with the support pad through-hole is provided on the outer end surface of the support pad. A base butt pipe corresponding to the tile butt pipe is provided on the annular base. The tile butt pipe is connected in the base butt pipe. The corrugated air guide pipe extends into the base butt pipe and passes through the tile butt pipe and enters the support pad through-hole.

[0017] Preferably, the tile butt pipe is connected in the base butt pipe through a differential bolt. The differential bolt is of a hollow structure for the corrugated air guide pipe to pass through. The free end of the tile butt pipe has an external thread with a small pitch. The inner wall of the differential bolt has an internal thread with a small pitch that mates with the external thread with a small pitch. The outer wall of the differential bolt has an external thread with a large pitch. The inner wall of the base butt pipe has an internal thread with a large pitch that mates with the external thread with a large pitch. The pitch of the internal thread with a small pitch is smaller than the pitch of the internal thread with a large pitch. The differential bolt is threadedly fitted and extends into the base butt pipe and is threadedly fitted with the tile butt pipe. A limiting strip for limiting the differential bolt is provided on the tile butt pipe. The limiting strip is arranged inside the external thread with a small pitch and contacts the end surface of the differential bolt as the differential bolt is screwed into the base butt pipe.

[0018] The dynamic adjustment method for the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing described above is characterized in that: according to the initial load-bearing requirement of the intelligent tilting pad hydrostatic gas bearing, the number and initial damping of the flexible damping components in the tilting pad assembly are adjusted to adjust the initial stiffness of the tilting pad assembly. During the load-bearing process, the vibration signals of the bearing are collected in real time by the piezoelectric ceramic induction adjuster and transmitted to the external control system. The external control system performs real-time calculation and analysis on the received vibration signals to obtain a voltage control signal and transmits it to the piezoelectric ceramic induction adjuster to control the piezoelectric ceramic induction adjuster to form a radial expansion and contraction deformation, adjust the damping characteristics of the flexible damping components, and form a dynamic adjustment of the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing.

[0019] The beneficial effects of the present invention are:

[0020] In the intelligent tilting pad hydrostatic gas bearing of the present invention, the flexible damping components are connected and supported between the support pad and the tilting pad along the radial direction, providing the tilting pad with initial rotational stiffness and radial stiffness. When the rotor rotates, the vibration of the tilting pad is absorbed, enabling the bearing to have stiffness and damping characteristics. Moreover, a piezoelectric ceramic induction adjuster is clamped between the tilting pad and the support pad to sense the vibration signals of the bearing in real time and transmit them to the external control system. The external control system controls the piezoelectric ceramic induction adjuster to perform radial expansion and contraction deformation according to the vibration signals of the bearing, so as to drive the radial deformation of the flexible damping component, change the rotational stiffness, radial stiffness and radial position of the tilting pad, realize the dynamic adjustment of the stiffness and damping characteristics of the bearing, thereby changing the critical frequency of the bearing-rotor system, broadening the speed range of stable operation of the bearing-rotor system, improving the load-bearing capacity of the bearing, and forming intelligent control of the bearing by using the signal transmission connection between the piezoelectric ceramic induction adjuster and the external control system, improving the stability of the bearing-rotor system with complex and variable rotor speeds.

[0021] The corrugated air duct is arranged along the radial direction and penetrates from the outside to the inside and is connected to the tilting pad. The corrugated air duct can form an adaptive deformation with the flexible damping component, and will not interfere with the movement of the tilting pad while guiding air, and forms a radial introduction of high-pressure air from the outside to the inside, which can effectively improve the reliability and efficiency of air guiding and reduce the gas leakage rate.

[0022] The supporting pad is connected to the annular base through a differential nut. The differential nut is in small-pitch thread fit with the pad docking pipe on the supporting pad and in large-pitch thread fit with the base docking pipe on the annular base. During installation, by rotating the differential nut on the base docking pipe, the radial position of the supporting pad is finely adjusted, thereby adjusting the clearance between the tilting pad and the rotor. This facilitates adjusting the radial position of the tilting pad according to the size and load-bearing requirements of the rotor, improving the installation efficiency of the bearing, achieving precise adjustment of the bearing clearance, enhancing the practicality of the bearing. The differential nut with a hollow structure supports the corrugated air pipe, effectively preventing the end bending of the corrugated air pipe and improving the air conduction reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of the intelligent tilting pad hydrostatic gas bearing in the specific embodiment.

[0024] Figure 2 It is a schematic diagram of the intelligent tilting pad hydrostatic gas bearing.

[0025] Figure 3 It is a combined schematic diagram of the porous graphite block tilting pad assembly and the piezoelectric ceramic induction adjustment part.

[0026] Figure 4 It is a schematic diagram of the tilting pad.

[0027] Figure 5 It is a cross-sectional view of the tilting pad.

[0028] Figure 6 It is a schematic diagram of the porous graphite block.

[0029] Figure 7 It is an exploded schematic diagram of the porous graphite block, the tilting pad assembly and the piezoelectric ceramic induction adjustment part.

[0030] Figure 8 It is a schematic diagram of the flexible damping part.

[0031] Figure 9 is a schematic diagram of the differential bolt.

[0032] Figure 10 It is a schematic diagram of the supporting pad.

[0033] Figure 11 It is a cross-sectional view of the supporting pad.

[0034] Figure 12 It is a half-sectional view of the annular base. SPECIFIC EMBODIMENTS

[0035] The following will be described in detail in conjunction with Figures 1 to 12 the embodiments of the present invention.

[0036] Intelligent tilting pad hydrostatic gas bearing, comprising a bearing housing 1, a tilting pad assembly 2 installed in the bearing housing 1, a porous graphite block 3 with an arc shape installed on the tilting pad assembly 2, and a corrugated gas pipe 4 for introducing gas onto the porous graphite block 3. The tilting pad assemblies 2 are evenly arranged along the circumferential direction of the bearing housing 1. It is characterized in that: the tilting pad assembly 2 includes a support pad 5 fitted and positioned on the inner wall of the bearing housing 1, a tilting pad 6 located radially inside the support pad 5, a flexible damping member 7 connecting the support pad 5 and the tilting pad 6 radially, and a piezoelectric ceramic induction adjustment member 8 that forms radial telescopic deformation under the control of an external control system. The porous graphite block 3 is installed at the inner end of the tilting pad 6. The piezoelectric ceramic induction adjustment member 8 is clamped between the tilting pad 6 and the support pad 5 and is signal-transmission connected to the external control system. The corrugated gas pipe 4 passes through the bearing housing 1, the support pad 5, and the piezoelectric ceramic induction adjustment member 8 radially and is connected to the tilting pad 6.

[0037] In the above-mentioned intelligent tilting pad hydrostatic gas bearing, the flexible damping member 7 connects the support pad 5 and the tilting pad 6 radially, provides the initial rotational stiffness and radial stiffness for the tilting pad 6, absorbs the vibration of the tilting pad during rotor rotation, enables the bearing to have stiffness-damping characteristics, and a piezoelectric ceramic induction adjustment member 8 is clamped between the tilting pad 6 and the support pad 5 to sense the vibration signal of the bearing in real time and transmit it to the external control system. The external control system controls the piezoelectric ceramic induction adjustment member 8 to perform radial telescopic deformation according to the vibration signal of the bearing, so as to drive the flexible damping member 7 to deform radially, change the rotational stiffness, radial stiffness, and radial position of the tilting pad, realize the dynamic adjustment of the stiffness-damping characteristics of the bearing, thereby changing the critical frequency of the bearing-rotor system, broadening the rotational speed range for the stable operation of the bearing-rotor system, improving the load-carrying capacity of the bearing, and forming intelligent control of the bearing by using the signal-transmission connection between the piezoelectric ceramic induction adjustment member and the external control system, improving the stability of the bearing-rotor system with complex and variable rotor speeds. The corrugated gas pipe 4 is arranged radially and penetrates from outside to inside and is connected to the tilting pad 6. The corrugated gas pipe 4 can form adaptive deformation with the flexible damping member 7, will not interfere with the movement of the tilting pad while conducting gas, and forms a radial introduction of high-pressure gas from outside to inside, which can effectively improve the reliability and efficiency of gas conduction and reduce the gas leakage rate.

[0038] Among them, a gas guiding groove 61 corresponding to the porous graphite block 3 is formed on the inner end surface of the tilting pad 6. The gas guiding groove 61 is communicated with the corrugated gas pipe 4. A raised clamping groove 62 arranged along the axial direction is formed on the inner wall of the gas guiding groove 61. A raised clamping bar 31 which is in clamping fit with the raised clamping groove is formed on the porous graphite block 3. The raised clamping bar 31 is clamped into the raised clamping groove 62 to embed the porous graphite block 3 into the gas guiding groove 61, and an arc-shaped gas storage cavity 63 is formed on the back surface of the porous graphite block 3. The porous graphite block 3 and the tilting pad 6 are connected through the clamping fit of the raised clamping bar 31 and the raised clamping groove 62. Compared with the bonding connection method, the installation of the porous graphite block 3 is more convenient and the porous graphite block 3 will not fall off from the tilting pad 6, improving the installation stability of the porous graphite block 3. The gas storage cavity 63 on the back surface of the porous graphite block 3 enables the gas to be evenly distributed on the back surface of the porous graphite block 3, so that the gas is evenly distributed on the outer surface of the porous graphite block 3, ensuring the bearing and lubricating effect on the shaft rotor.

[0039] Among them, the raised clamping groove 62 is a strip-shaped groove with a T-shaped cross section, and the raised clamping bar 31 is a clamping bar with a T-shaped cross section. A side opening 64 is formed on one side of the gas guiding groove 61. The raised clamping bar 31 extends into the raised clamping groove 62 from the side opening 64. A sealing gasket 9 and a sealing gasket pressing plate 10 are arranged on the side opening 64. The sealing gasket pressing plate 10 is fixed to the tilting pad 6 through bolts and presses the sealing gasket 9. The sealing gasket 9 presses the arc-shaped side surface of the porous graphite block 3, and presses the porous graphite block 3 axially in the gas guiding groove 62. After aligning the raised clamping bar 31 with the raised clamping groove 62 and pushing it axially into the raised clamping groove 62 from the side opening 64, the connection between the porous graphite block 3 and the tilting pad 6 is formed. The formation of the side opening 64 enables the rapid installation of the porous graphite block 3. The sealing gasket 9 presses on the side of the porous graphite block 3, and the sealing gasket pressing plate 10 presses the sealing gasket 9, thereby pressing the porous graphite 3 axially in the gas guiding groove 62, sealing the gas guiding groove 61, reducing the gas leakage rate in the gas storage cavity 63, and improving the damping reliability of the bearing.

[0040] Among them, a gas guiding through hole 65 communicating the corrugated gas pipe 4 and the gas guiding groove 61 is formed on the tilting pad 6. A docking end ring 66 communicated with the gas guiding through hole is arranged on the outer end surface of the tilting pad 6. The inner end of the corrugated guiding pipe 4 is sleeved on the docking end ring 66. The docking end ring 66 positions the inner end of the corrugated gas pipe 4, ensuring the alignment and connection between the corrugated guiding pipe 4 and the gas guiding through hole 65. High-pressure gas enters from the corrugated gas pipe 4, enters the gas storage cavity 63 through the gas guiding through hole 65, and then forms lubrication and bearing on the rotor through the porous graphite block 3.

[0041] Among them, the flexible damping member 7 is symmetrically arranged on both sides of the piezoelectric ceramic induction adjustment member 8. T-shaped connection grooves 51 for connecting the flexible damping member 8 are formed on the inner end surface of the support pad 5 and the outer end surface of the tilting pad 6. T-shaped connection ends 71 corresponding to the T-shaped connection grooves 51 are arranged at both ends of the flexible damping member 7. The flexible damping member 7 is a stainless steel sheet with a wavy shape along the radial direction. The cooperation between the T-shaped connection groove 51 and the T-shaped connection end 71 enables the flexible damping member 7 to be axially pushed in for installation, quickly connecting the tilting pad 6 and the support pad 5. The flexible damping member 7 is made of stainless steel, with different thicknesses and wavy shapes, resulting in different initial damping values. During the damping deformation process after loading, it is also different. Therefore, the initial damping and the stiffness damping characteristics during bearing loading can be adjusted by adjusting the thickness, shape or material of the flexible damping member 7.

[0042] Among them, the inner end faces of the supporting pad blocks 5 and the outer end faces of the tilting pad blocks 6 are both flat surfaces. The piezoelectric ceramic induction adjusting member 8 is clamped between the inner end face of the supporting pad block 5 and the outer end face of the tilting pad block 6, and includes a piezoelectric ceramic block 81 that expands and contracts radially along with the signal control of an external system and a PVDF sensor 82 for sensing the bearing vibration signal. The piezoelectric ceramic block 81 is sleeved outside the corrugated air duct 4 and is in contact with the inner end face of the supporting pad block 5. The PVDF sensor 82 is clamped between the piezoelectric ceramic block 81 and the tilting pad block 6. The connecting wires of the piezoelectric ceramic block 81 and the connecting wires of the PVDF sensor 82 respectively pass through the bearing housing 1 and are connected to an external control system. The PVDF sensor 82 is in the shape of a thin sheet and the number is two. The two PVDF sensors 82 are symmetrically arranged on both sides of the corrugated air duct 4. The PVDF sensor 82 senses the vibration signal of the bearing in real time, including the vibration frequency and vibration amplitude of the bearing, and transmits it to the external control system. The external control system performs real-time calculation and analysis on the adopted vibration signal, judges the operating state of the bearing and forms a corresponding voltage control signal to be sent to the piezoelectric ceramic block 81 to control the piezoelectric ceramic block 81 to expand and contract radially. Among them, the piezoelectric ceramic block 81 has the property of spontaneous polarization, and the spontaneous polarization can be changed under the action of an external electric field. When an external electric field identical to the spontaneous polarization is applied, it is equivalent to enhancing the polarization intensity. The increase in the polarization intensity causes the piezoelectric ceramic block to elongate along the polarization direction. If a reverse electric field is applied, the voltage ceramic block shortens along the polarization direction, forming the inverse piezoelectric effect. By controlling the voltage value of the piezoelectric ceramic block 81 through the external control system to cause it to generate radial expansion and contraction deformation, when the rotor speed increases and the bearing vibration frequency and amplitude increase, the external control system controls the piezoelectric ceramic block 81 to elongate radially, thereby driving the flexible damping member 7 to elongate radially, improving the damping of the flexible damping member, enhancing the radial stiffness and rotational stiffness of the tilting pad block, and pushing the tilting pad block 6 inward, reducing the clearance between the bearing and the rotor, and improving the stability of the bearing. When the rotor speed decreases and the bearing vibration frequency and amplitude decrease, the external control system will control the piezoelectric ceramic block 81 to retract radially, thereby causing the flexible damping member 7 to retract radially. The vibration energy of the bearing is consumed through the deformation of the flexible damping member 7 to keep the bearing stable, realizing the dynamic adjustment of the stiffness and damping characteristics of the bearing, thereby changing the critical frequency of the bearing-rotor system, broadening the speed range of stable operation of the bearing-rotor system, and improving the load-carrying capacity of the bearing. By using the signal transmission connection between the piezoelectric ceramic induction adjusting member 8 and the external control system, intelligent control of the bearing is formed, and the stability of the bearing-rotor system with complex and variable rotor speeds is improved.

[0043] Among them, the bearing housing 1 includes an annular base 11 and a base cover plate 12 covering the end face of the annular base 11. The tilting pad assembly 2 is installed in the cavity formed by the annular base 11 and the base cover plate 12 and is connected to the annular base 11. The base cover plate 12 axially positions the tilting pad assembly 2 to prevent the relative axial movement of the tilting pads 6, the supporting pads 5, the flexible damping members 7, and the piezoelectric ceramic blocks 81, and forms an enclosure for the tilting pad assembly 2 to protect the tilting pad assembly 2.

[0044] Among them, the supporting pad 5 is provided with a supporting pad through hole 52 for the corrugated air duct to pass through. The outer end face of the supporting pad 5 has a pad docking pipe 53 communicating with the supporting pad through hole 52. The annular base 11 has a base docking pipe 13 corresponding to the pad docking pipe 53. The pad docking pipe 53 is connected in the base docking pipe 13. The corrugated air duct 4 extends into the base docking pipe 13 and passes through the pad docking pipe 53 and enters the supporting pad through hole 52. The supporting pad 5 supports and positions the entire tilting pad assembly 2. The pad docking pipe 53 extends into and is connected to the base docking pipe 13 to position the tilting pad assembly 2 on the bearing housing 1. At the same time, through the connection between the pad docking pipe 53 and the base docking pipe 13, an adjustable structure for the radial position of the supporting pad 5 is formed, which is convenient for fine-tuning the radial position of the tilting pads 6 during installation.

[0045] Among them, the tile docking pipe 53 is connected to the base docking pipe 13 through a differential bolt 14. The differential bolt 14 has a hollow structure for the corrugated air duct 4 to pass through. The free end of the tile docking pipe 53 has a small-pitch external thread 531. The inner wall of the differential bolt 14 has a small-pitch internal thread 141 that mates with the small-pitch external thread 531. The outer wall of the differential bolt 14 has a large-pitch external thread 142. The inner wall of the base docking pipe 13 has a large-pitch internal thread 131 that mates with the large-pitch external thread 142. The pitch of the small-pitch internal thread 141 is smaller than the pitch of the large-pitch internal thread 131. The differential bolt 14 is threadedly fitted into the base docking pipe 13 and threadedly fitted with the tile docking pipe 53. The tile docking pipe 53 is provided with a limit stop strip 54 for limiting the differential bolt. The limit stop strip 54 is arranged inside the small-pitch external thread 531 and contacts the end face of the differential bolt 14 as the differential bolt 14 is screwed into the base docking pipe 53. As can be seen from the drawings, the differential bolt has a hollow structure, with a small-pitch internal thread 141 on the inner wall and a large-pitch external thread 142 on the outer wall. The small-pitch internal thread 141 forms a threaded fit with the small-pitch external thread 531 on the tile docking pipe 53, and the large-pitch external thread 142 forms a threaded fit with the large-thread internal thread 131 on the base docking pipe 13. The differential bolt 14 connects the tile docking pipe 53 and the base docking pipe 13. Rotating the differential bolt 14 can form a fine adjustment of the radial position of the tile docking pipe 53. During installation, by rotating the differential nut 14 on the base docking pipe 13, the radial position of the support tile 5 is finely adjusted, so as to adjust the clearance between the tilting pad 6 and the rotor, facilitate adjusting the radial position of the tilting pad 6 according to the size and load-bearing requirements of the rotor, improve the installation efficiency of the bearing, achieve precise adjustment of the bearing clearance, enhance the practicality of the bearing. The hollow-structured differential nut 14 supports the corrugated air duct 4, effectively preventing the end bending of the corrugated air duct and improving the air conduction reliability.

[0046] The present invention also provides a method for dynamically adjusting the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing described above, which is characterized in that: according to the initial load-bearing requirements of the intelligent tilting pad hydrostatic gas bearing, the number and initial damping of the flexible damping members in the tilting pad assembly 2 are adjusted to adjust the initial stiffness of the tilting pad assembly 2. During the load-bearing process, the vibration signal of the bearing is collected in real time by the piezoelectric ceramic induction adjustment member 8 and transmitted to the external control system. The external control system performs real-time calculation and analysis on the received vibration signal to obtain a voltage control signal and transmits it to the piezoelectric ceramic induction adjustment member 8 to control the piezoelectric ceramic induction adjustment member 8 to form a radial telescopic deformation, adjust the damping characteristics of the flexible damping member 7, and form a dynamic adjustment of the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing.

[0047] For the dynamic adjustment method of the stiffness damping characteristics described above, the flexible damping member 7 provides the initial rotational stiffness and radial stiffness for the tilting pad 6, absorbs the vibration of the tilting pad during rotor rotation, so that the bearing has the stiffness damping characteristics. The initial damping and the stiffness damping characteristics during the bearing load-bearing process can be adjusted by adjusting the thickness, shape or material of the flexible damping member 7. And a piezoelectric ceramic induction adjustment member 8 is clamped between the tilting pad 6 and the support pad 5 to sense the vibration signal of the bearing in real time and transmit it to the external control system. The external control system controls the piezoelectric ceramic induction adjustment member 8 to radially expand and contract according to the vibration signal of the bearing, so as to drive the flexible damping member 7 to radially deform, change the rotational stiffness, radial stiffness and radial position of the tilting pad, realize the dynamic adjustment of the stiffness damping characteristics of the bearing, thereby changing the critical frequency of the bearing-rotor system, broadening the rotational speed range for the stable operation of the bearing-rotor system, improving the load-bearing capacity of the bearing, and using the signal transmission connection between the piezoelectric ceramic induction adjustment member and the external control system to form intelligent control of the bearing, improving the stability of the bearing-rotor system with complex and variable rotor speeds.

[0048] The technical solutions of the embodiments of the present invention have been completely described in combination with the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

Claims

1. The intelligent tilting pad hydrostatic gas bearing includes a bearing housing, a tilting pad assembly installed in the bearing housing, a porous graphite block with an arc shape installed on the tilting pad assembly, and a corrugated gas pipe for introducing gas onto the porous graphite block. The tilting pad assemblies are evenly arranged along the circumferential direction of the bearing housing, and it is characterized in that: The described tilting pad assembly includes support pads that are fitted and positioned on the inner wall of the bearing housing, tilting pads located radially inside the support pads, flexible damping members that connect the support pads and the tilting pads along the radial direction, and piezoelectric ceramic induction adjustment members that are controlled by an external control system to form radial telescopic deformation. A porous graphite block is installed at the inner end of the tilting pad. The piezoelectric ceramic induction adjustment members are clamped between the tilting pads and the support pads and are signal-transmission connected to the external control system. The corrugated air duct passes through the bearing housing, the support pads, and the piezoelectric ceramic induction adjustment members along the radial direction and is connected to the tilting pads. The described support pads are provided with support pad through-holes for the corrugated air duct to pass through. The outer end face of the support pads has a pad docking pipe that is connected to the support pad through-hole. The annular base has a base docking pipe corresponding to the pad docking pipe. The pad docking pipe is connected in the base docking pipe. The corrugated air duct extends into the base docking pipe and passes through the pad docking pipe and enters the support pad through-hole. The described pad docking pipe is connected in the base docking pipe through a differential bolt. The differential bolt has a hollow structure for the corrugated air duct to pass through. The free end of the pad docking pipe has a small-pitch external thread. The inner wall of the differential bolt has a small-pitch internal thread that mates with the small-pitch external thread. The outer wall of the differential bolt has a large-pitch external thread. The inner wall of the base docking pipe has a large-pitch internal thread that mates with the large-pitch external thread. The pitch of the small-pitch internal thread is smaller than the pitch of the large-pitch internal thread. The differential bolt is threadedly mated and extends into the base docking pipe and is threadedly mated with the pad docking pipe. The pad docking pipe has a limit stop strip for limiting the differential bolt. The limit stop strip is arranged inside the small-pitch external thread and contacts the end face of the differential bolt as the differential bolt is screwed into the base docking pipe.

2. The intelligent tilting pad hydrostatic gas bearing according to claim 1, wherein: The inner end face of the described tilting pad is provided with an air guide groove corresponding to the porous graphite block. The air guide groove is connected to the corrugated air duct. The inner wall of the air guide groove has a raised card slot arranged along the axial direction. The porous graphite block has a raised card strip that is snap-fitted with the raised card slot. The raised card strip is snapped into the raised card slot to embed the porous graphite block into the air guide groove and form an arc-shaped air storage cavity on the back of the porous graphite block.

3. The intelligent tilting pad hydrostatic gas bearing according to claim 2, wherein: The described raised card slot is a strip-shaped groove with a T-shaped cross-section. The raised card strip is a strip with a T-shaped cross-section. A side opening is provided on one side of the air guide groove. The raised card strip extends into the raised card slot from the side opening. A gasket and a gasket pressing plate are padded on the side opening. The gasket pressing plate is fixed to the tilting pad by bolts and presses the gasket. The gasket presses the arc-shaped side of the porous graphite block to axially press the porous graphite block in the air guide groove.

4. The intelligent tilting pad hydrostatic gas bearing according to claim 2, wherein: The described tilting pad is provided with an air guide through-hole that connects the corrugated air duct and the air guide groove. The outer end face of the tilting pad is provided with a docking end ring that is connected to the air guide through-hole. The inner end of the corrugated air duct is sleeved on the docking end ring.

5. The intelligent tilting pad hydrostatic gas bearing according to claim 1, wherein: The described flexible damping members are symmetrically arranged on both sides of the piezoelectric ceramic induction adjusting member. T-shaped connection grooves for connecting the flexible damping members are provided on the inner end faces of the support pads and the outer end faces of the tilting pads. T-shaped connection ends corresponding to the T-shaped connection grooves are provided at both ends of the flexible damping member. The flexible damping member is a stainless steel sheet with a wavy shape along the radial direction.

6. The intelligent tilting pad hydrostatic gas bearing according to claim 1, wherein: The inner end faces of the described support pads and the outer end faces of the tilting pads are both flat surfaces. The piezoelectric ceramic induction adjusting member is sandwiched between the inner end face of the support pad and the outer end face of the tilting pad, and includes a piezoelectric ceramic block that expands and contracts radially along with the signal control of an external system and a PVDF sensor for sensing the vibration signal of the bearing. The piezoelectric ceramic block is sleeved outside the corrugated air pipe and is in contact with the inner end face of the support pad. The PVDF sensor is sandwiched between the piezoelectric ceramic block and the tilting pad. The connecting wires of the piezoelectric ceramic block and the connecting wires of the PVDF sensor respectively pass through the bearing housing and are connected to an external control system. The PVDF sensor is in the shape of a thin sheet and the number is two. The two PVDF sensors are symmetrically arranged on both sides of the corrugated air pipe.

7. The intelligent tilting pad hydrostatic gas bearing according to claim 1, characterized in that: The described bearing housing includes an annular base and a base cover plate covering the end face of the annular base. The tilting pad assembly is installed in the cavity formed by the annular base and the base cover plate and is connected to the annular base.

8. The dynamic regulation method for the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing according to any one of claims 1 to 7, characterized in that: According to the initial load-bearing requirements of the described intelligent tilting pad hydrostatic gas bearing, adjust the number and initial damping of the flexible damping members in the tilting pad assembly to adjust the initial stiffness of the tilting pad assembly. During the load-bearing process, the vibration signal of the bearing is collected in real time by the piezoelectric ceramic induction adjusting member and transmitted to the external control system. The external control system performs real-time calculation and analysis on the received vibration signal to obtain a voltage control signal and transmits it to the piezoelectric ceramic induction adjusting member to control the piezoelectric ceramic induction adjusting member to form a radial expansion and contraction deformation, adjust the damping characteristics of the flexible damping members, and form a dynamic adjustment of the stiffness and damping characteristics of the intelligent tilting pad hydrostatic gas bearing.

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