An adjustable damping tilting pad gas bearing

Abstract

This invention provides an adjustable damping tilting pad gas bearing, relating to the field of gas bearing technology. It solves the problem of non-adjustable damping in existing gas bearings during rotor system operation, allowing for adjustment of system stability under different operating conditions. The invention comprises: a tilting pad bearing body, a top foil, a corrugated foil, a magnet, a coil, a controllable rheostat, a baffle, and screws. The magnet, fixed to the tilting pad cantilever, is placed within the coil connected to the controllable rheostat. The coil is fixed to the baffle, and its height is adjusted by screws. When the high-speed rotor vibrates, the rotor load is transmitted to the tilting pad cantilever via the top foil and corrugated foil, driving the magnet to vibrate. This vibration energy is converted into coil electrical energy, controlling the supply voltage of the controllable rheostat and changing its resistance value to control the system's damping effect. The top foil and corrugated foil bear the rotor's impact load and provide a certain degree of support stiffness and damping. Compared to traditional gas hydrodynamic bearings, this invention can effectively adjust the system's damping, achieving the function of controlling system stability, and has a simple support structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radial gas bearing, in particular to a tilting-pad gas bearing with adjustable damping. BACKGROUND

[0002] The traditional foil gas dynamic pressure bearing is a dynamic pressure bearing using ambient gas as lubricating medium, the foil structure improves the support stiffness and friction damping, has the advantages of simple structure, oil-free lubrication, low energy consumption, high efficiency output, etc., and can support the rotor to work continuously under high-speed working condition, and is widely used in high-performance mechanical equipment such as micro gas turbine, micro turbojet engine, fuel cell air compressor, etc.

[0003] Because the foil structure surface of the foil gas dynamic pressure bearing and the rotor surface enclose the gas film gradient velocity, cross stiffness is generated, so that the rotor system supported by the bearing will inevitably have certain subsynchronous vibration problem at a certain speed, which limits the development of the gas dynamic pressure bearing to higher speed. The effective measure to reduce the vibration of the system is to provide sufficient damping to the system, but the damping of the foil gas dynamic pressure bearing only comes from the mutual friction of the foil structure, and the friction damping decreases with the increase of the vibration frequency and tends to be stable, which cannot provide sufficient damping effect for the rotor system. Therefore, the rotor system supported by the foil gas dynamic pressure bearing can only work below the second-order resonance frequency of the rotor, and cannot reach the third-order resonance frequency of the rotor system. SUMMARY

[0004] In view of the above technical deficiencies, the present application provides a tilting-pad gas bearing with adjustable damping to solve the technical problems of insufficient damping effect and poor stability of the existing radial foil gas dynamic pressure bearing under high-speed working condition. The preferred technical solutions in the technical solutions provided by the present application can produce the technical effects described below.

[0005] To achieve the above technical purposes, the present application provides the following technical solutions.

[0006] The tilting-pad gas bearing with adjustable damping provided by the present application comprises a tilting-pad bearing body, a top foil, a wave foil, a magnet, a coil, a baffle, a screw and a controllable resistor.

[0007] The tilting-pad bearing body is integrally formed by electric spark wire cutting method, eliminating the installation error of the structure, and is composed of a tilting-pad body, a tilting-pad support longitudinal part, a tilting-pad support transverse part, a tilting-pad cantilever and a groove, wherein the tilting-pad support longitudinal part and the tilting-pad support transverse part jointly support the tilting-pad body, ensuring a certain degree of rotation and vibration of the tilting-pad body, and a plurality of tilting-pad cantilevers are distributed on both sides of the tilting-pad support.

[0008] The tilting-pad cantilever has a certain thickness and does not deform during vibration, and transmits the vibration of the tilting-pad body; the tilting-pad cantilever is fixed with magnets having strong magnetism on both sides, the tilting-pad cantilever with the magnets is arranged in the middle of a coil, and a gap is ensured between the magnets and the coil, and there is no collision and contact between the two during system operation.

[0009] The number of turns of the coil is obtained according to actual requirements, the surface of the coil is insulated and resistant to high temperature, controllable resistors are connected at both ends of the coil, and the resistance is controlled by a power supply voltage. When the controllable resistor is disconnected, there is no damping effect; when the resistance value of the controllable resistor is small, the coil is connected at both ends, at this time, the tilting-pad cantilever drives the magnets to vibrate, so that the coil is in a changing magnetic field, the vibration mechanical energy of the tilting-pad cantilever is converted into the electric energy of the coil, and the tilting-pad cantilever has a damping effect.

[0010] The holes in the baffle fix the coil on the baffle, and the circumferential width of the baffle and the coil is consistent with the width of the groove, so that the shaking of the baffle and the coil is reduced.

[0011] The screw passes through the threaded holes of the tilting-pad bearing body and the baffle, limits the position of the baffle, and makes the distance between the baffle and the tilting-pad cantilever minimum.

[0012] The top foil and the wave foil are pressed from metal foil sheets and are subjected to heat treatment for a certain length of time, so that the top foil and the wave foil are maintained in a certain shape; the surface of the top foil has a metal coating for reducing the friction between the bearing during start and stop and the rotor; after a load is applied, the top foil and the wave foil will deform to a certain extent, and the two are fixed on the surface of the tilting-pad body.

[0013] Optionally, the top foil and the wave foil provide a certain stiffness and damping, the surface of the top foil and the surface of the rotor surround the gas film space, and therefore other types of structures capable of providing stiffness and damping can be used, such as a multi-layer mesh structure intersecting and overlapping, a metal mesh and the like.

[0014] Optionally, the top foil and the wave foil can be replaced by a porous material with a certain porosity, regular grooves are engraved on the surface of the tilting-pad body, and the porous material is fixed on the surface of the tilting-pad body; at this time, high-pressure gas enters the grooves through the threaded holes on the tilting-pad body, and then directly acts on the rotor through the surface of the porous material.

[0015] The tilting-pad gas bearing provided by the application can adjust the damping, the tilting-pad body drives the magnets on both sides of the tilting-pad cantilever to vibrate in the middle of the coil provided with a controllable resistor, the induced magnetic field generated by the movement of the magnets causes the coil to generate an induced electromotive force, the vibration mechanical energy of the tilting-pad body is converted into the electric energy of the coil, the energy of the system is consumed, the amount of energy is positively correlated with the vibration frequency, the amount of consumed energy can be adjusted by adjusting the resistance value of the controllable resistor, the tilting-pad gas bearing can provide a variable damping effect for the rotor in a high-speed working condition, and the stability of the system is improved. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 An isometric view of an adjustable damping tilting pad gas bearing provided for an embodiment of the present invention.

[0018] Figure 2 An exploded view of an adjustable damping tilting pad gas bearing provided for an embodiment of the present invention.

[0019] Figure 3 This is a partially enlarged view of an adjustable damping tilting pad gas bearing provided in an embodiment of the present invention.

[0020] Figure 4 This is a cross-sectional view of the bearing body of an adjustable damping tilting pad gas bearing provided in an embodiment of the present invention.

[0021] Figure 5 The image shows a front view of the bearing body of an adjustable damping tilting pad gas bearing provided in an embodiment of the present invention.

[0022] Figure 6 This is a top view of the baffle of an adjustable damping tilting pad gas bearing provided in an embodiment of the present invention.

[0023] Figure 7 This is a schematic diagram of another type of structure of an adjustable damping tilting pad gas bearing provided for an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] In the description of the present application, it is necessary to explain that, unless otherwise stated, the meaning of "a plurality of" is two or more; the meaning of the term "fixed" is a broad sense of fixed mode, including but not limited to welding, bolt, wedge, magnetic attraction, gluing and the like; the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application.

[0026] The present application provides a kind of adjustable damping tilting pad gas bearing, including including tilting pad bearing body (1), top foil (2), wave foil (3), magnet (4), coil (5), baffle (6), screw (7), controllable resistor (8).

[0027] Tilting pad bearing body (1) is integrally formed by wire cut electrical discharge, and the shape of tilting pad body (111), tilting pad support longitudinal portion (112), tilting pad support transverse portion (113), tilting pad cantilever (114) and groove (115) is cut out, there are a plurality of tilting pad bodies (111) in the circumferential direction of the bearing, the adjacent tilting pad bodies (111) move independently, wherein the tilting pad support longitudinal portion (112) and the tilting pad support transverse portion (113) jointly support the tilting pad body (111), ensure the rotation and vibration of the tilting pad body (111) to a certain extent, a plurality of tilting pad cantilevers (114) are distributed on both sides of the tilting pad support longitudinal portion (112), and the depth of the groove (115) is greater than the length of the tilting pad cantilever (114).

[0028] Tilting pad cantilever (114) has a certain thickness, and the connecting part of tilting pad body (111) is rounded to reduce stress concentration and ensure that tilting pad cantilever (114) does not deform during vibration and only transmits the vibration of tilting pad body (111), the magnet (4) with strong magnetism is fixed on both sides of the tilting pad cantilever (114), the tilting pad cantilever (114) with the magnet (4) is placed in the middle of the coil (5), and the magnet (4) and the coil (5) have a gap to avoid collision and contact between them during system operation.

[0029] The number of turns, wire diameter and other size parameters of the coil (5) are calculated according to actual requirements, the surface of the coil (5) is coated with an insulating and high-temperature-resistant material, and the two ends of the coil (5) are connected to the controllable resistor (8), the size of the resistance is controlled by the power supply voltage. When the controllable resistor (8) is disconnected, there is no damping effect; when the resistance value of the controllable resistor (8) is small, the coil (5) is connected at both ends to form a closed loop, at this time the tilting pad cantilever (114) drives the magnet (4) to vibrate, so that the coil (5) is in a changing magnetic field, and the vibration energy of the tilting pad cantilever (114) is converted into electrical energy of the coil (5), thereby damping the tilting pad cantilever (114).

[0030] The holes on the baffle (6) fix the coil (5) on the baffle, the circumferential width of the baffle (6) and the coil (5) is consistent with the width of the groove (115), thereby reducing the shaking of the baffle (6) and the coil (5).

[0031] The screw (7) passes through the threaded holes of the tilting pad bearing body (1) and the baffle (6), limits the position of the baffle (6), and makes the distance between the baffle (6) and the tilting pad cantilever (114) smallest.

[0032] The top foil (2) and the wave foil (3) are pressed from metal foil sheets and are subjected to heat treatment for a certain period of time to maintain the top foil (2) and the wave foil (3) in a certain shape, the surface of the top foil (2) has a metal coating for reducing friction between the bearing during start and stop and the rotor, and the top foil and the wave foil will deform after a load is applied, and are fixed on the surface of the tilting pad body.

[0033] The top foil (2) and the wave foil (3) provide a certain stiffness and damping, the surface of the top foil and the surface of the rotor surround the air film space, so other types of structures that can provide stiffness and damping can be used, such as a multi-layer mesh structure that is crossed and overlapped, a metal mesh, and the like.

[0034] Optionally, the tilting pad cantilever (114) can be truncated along the bearing axis and divided into multiple groups, and cooperates with the magnet (4) and the coil (5) to form multiple controllable damping structures.

[0035] Optionally, the tilting pad support transverse part (113) can be truncated along the bearing axis and divided into multiple groups, thereby providing a deformation space for the vibration of the high-speed rotor.

[0036] Optionally, the top foil (2) and the wave foil (3) can be replaced by a porous material (9) with a certain porosity, and regular grooves are engraved on the surface of the tilting pad body (111), and the porous material (9) is fixed on the surface of the tilting pad body (111), at this time, high-pressure gas enters the grooves through the threaded holes (10) on the tilting pad body (111), and then directly acts on the rotor through the surface of the porous material (9).

[0037] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A tilting pad gas bearing of adjustable damping, characterized by It includes tilting pad bearing body (1), top foil (2), wave foil (3), magnet (4), coil (5), baffle (6), screw (7), controllable resistor (8); the tilting pad bearing body (1) is integrally formed by wire cutting mode, which is composed of tilting pad body (111), tilting pad support longitudinal part (112), tilting pad support transverse part (113), tilting pad cantilever (114), groove (115); the magnet (4) is fixed on both sides of the tilting pad cantilever (114) and moves with the tilting pad body; the controllable resistor (8) is connected to the end of the coil (5), and the resistance of the controllable resistor (8) is controlled by the power supply voltage; the coil (5) with a certain number of turns is fixed on the baffle, the tilting pad cantilever (114) is placed in the middle of the coil, and the tilting pad cantilever (114) is guaranteed to have a gap with the coil during vibration, and no contact or collision occurs.

2. The tilting pad gas bearing of adjustable damping according to claim 1, characterized in that The tilting pad bearing body (1) is integrally formed by wire cutting mode, wherein the tilting pad support longitudinal part (112) and the tilting pad support transverse part (113) jointly support the tilting pad body (111), and guarantee the rotation and vibration of the tilting pad body (111) to a certain extent, and a plurality of tilting pad cantilevers (114) are distributed on both sides of the tilting pad support.

3. The tilt pad gas bearing of variable damping according to claim 1, wherein, The tilting pad cantilever (114) has a certain thickness and does not deform during vibration, and transmits the vibration of the tilting pad body (111); the magnet (4) with strong magnetism is fixed on both sides of the tilting pad cantilever (114), and the tilting pad cantilever (114) with the magnet is placed in the middle of the coil (5), so that a gap is guaranteed between the magnet and the coil, and there is no expansion or contact between them during system operation.

4. The tilt pad gas bearing of variable damping according to claim 1, wherein, The number of turns of the coil (5) is calculated according to actual requirements, the coil (5) is connected to the controllable resistor (8) at both ends, and the resistance is controlled by the power supply voltage; when the controllable resistor (8) is disconnected, there is no damping effect; when the resistance value of the controllable resistor is small, the coil is connected at both ends, at this time, the tilting pad cantilever (114) drives the magnet (4) to vibrate, so that the coil (5) is in a changing magnetic field, the vibration energy of the tilting pad cantilever (114) is converted into electric energy of the coil (5), and the tilting pad cantilever (114) has a damping effect.

5. The tilt pad gas bearing of variable damping according to claim 1, wherein, The hole in the baffle (6) fixes the coil (5) on the baffle (6), the circumferential width of the baffle (6) and the coil (5) is consistent with the width of the groove (115), and the shaking of the baffle and the coil is reduced.

6. The tilt pad gas bearing of variable damping according to claim 1, wherein, The screw (7) passes through the threaded holes of the tilting pad bearing body (1) and the baffle (6), limits the position of the baffle, and makes the distance between the baffle (6) and the tilting pad cantilever (114) minimum.

7. The tilt pad gas bearing of variable damping according to claim 1, wherein, The top foil (2) and the wave foil (3) are pressed from metal foil, and will deform after a load is applied; the two are fixed on the surface of the tilting pad body (111), the surface of the top foil has a metal coating, which is used to reduce the friction between the bearing start-stop process and the rotor.

8. The tilt pad gas bearing of variable damping according to claim 1, wherein, The top foil (2) and wave foil (3) provide certain stiffness and damping, the top foil surface and rotor surface surround the air film space, so other types of structures that can provide stiffness and damping can be used, such as multi-layer mesh structure cross-over, wire mesh and the like.

9. The tilt pad gas bearing of variable damping according to claim 1, wherein, The top foil (2) and wave foil (3) can be replaced by a porous material (9) with a certain porosity, the surface of the tilting pad (111) is engraved with regular grooves, and the porous material (9) is fixed on the surface of the tilting pad (111), at this time, the high-pressure gas enters the groove through the threaded hole (10) on the tilting pad (111), and then emerges from the surface of the porous material (9) to directly act on the rotor.

10. The tilt pad gas bearing of variable damping according to claim 1, wherein, The tilting pad cantilever (114) can be truncated along the bearing axial direction, divided into multiple groups, and cooperated with the magnet (4) and the coil (5) to form multiple controllable damping structures; the tilting pad support transverse part (113) can be truncated along the bearing axial direction, divided into multiple groups, and provide deformation space for the vibration of the high-speed rotor.

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