An elastic foil gas bearing with adjustable support stiffness and a transmission device

Abstract

The present invention belongs to the field of mechanical transmission technology and discloses an elastic foil gas bearing with adjustable support stiffness and a transmission device. The elastic foil gas bearing is designed to be mounted on a corresponding shaft journal and includes an elastic foil gas bearing body and a drive device. The elastic foil gas bearing body includes a first stiffness bearing area and a second stiffness bearing area along the circumference, with the first stiffness bearing area having greater stiffness than the second stiffness bearing area. The drive device is used to rotate the elastic foil gas bearing body to adjust the bearing area in contact with the shaft journal. The present invention can improve the stability of the elastic foil gas bearing rotor system by changing the air film bearing area of the elastic foil bearing in real time.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical transmission, and more specifically, relates to an elastic foil gas bearing with adjustable support stiffness and a transmission device. Background Art

[0002] Bearings are components that fix and reduce the load friction coefficient during mechanical transmission. Their main function is to support mechanical rotating bodies and reduce the mechanical load friction coefficient of the equipment during transmission. In recent years, with the increasing application of high-speed rotating machinery in aerospace, energy equipment and other fields, the working environment has become increasingly harsh, and the requirements for lubrication and support have gradually increased. In oil-free lubrication systems, compared with complex and expensive support methods such as electromagnetic bearings, elastic foil gas bearings have the advantages of high speed, good adaptability, no wear, low cost, high reliability, and high temperature resistance. They do not require additional auxiliary devices such as oil supply and have a simple structure. They are one of the key technologies for oil-free lubrication.

[0003] However, due to the low specific load capacity and narrow stable zone of elastic foil gas bearings, they are prone to instability when running at high speed and high load.

[0004] Changing the geometric parameters of the bearing foil can improve the stability of the bearing-rotor system in a specific state, but it is difficult to meet the requirements for the stability of the bearing-rotor system in multiple states. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the present invention innovatively provides a mechanism for real-time changing the installation position of the elastic foil gas bearing body to adjust the support stiffness. The mechanism has the characteristics of simple structure and precise adjustment of the bearing installation position. This mechanism can improve the stability of the elastic foil gas bearing rotor system by real-time changing the air film bearing area of the elastic foil bearing.

[0006] To achieve the above technical objectives, the present invention discloses, in a first aspect, an elastic foil gas bearing with adjustable support stiffness, which is used to be mounted on a matching shaft neck, and includes an elastic foil gas bearing body, the elastic foil gas bearing body being mounted on the shaft neck, and also includes a drive device;

[0007] The elastic foil gas bearing body includes a first stiffness bearing area and a second stiffness bearing area along the circumferential direction, wherein the stiffness of the first stiffness bearing area is greater than the stiffness of the second stiffness bearing area.

[0008] The driving device is used to drive the elastic foil gas bearing body to rotate so as to adjust the bearing area in contact with the shaft journal.

[0009] Furthermore, the elastic foil gas bearing body also includes a third stiffness bearing area, the first stiffness bearing area, the second stiffness bearing area and the third stiffness bearing area are arranged along the circumference of the elastic foil gas bearing body, and the stiffness of the third stiffness bearing area is greater than the stiffness of the first stiffness bearing area.

[0010] Furthermore, the elastic foil gas bearing body includes a bottom arch foil and a top foil; the top foil is arc-shaped and partially fits on the shaft neck; the bottom arch foil is correspondingly supported on the outer side of the top foil.

[0011] Furthermore, a bearing sleeve is provided on the outer fixed sleeve of the elastic foil gas bearing body, and the driving device is connected to the bearing sleeve through a transmission device.

[0012] Furthermore, the transmission device includes a worm wheel and a worm meshing with the worm wheel, and the worm wheel is sleeved on the bearing sleeve and fixedly connected to the bearing sleeve.

[0013] Furthermore, a rotating bearing is sleeved on the outside of the bearing sleeve to reduce the rotational resistance of the bearing sleeve.

[0014] Furthermore, the rotary bearing is a ball bearing, a roller bearing or a tapered bearing.

[0015] Furthermore, a mounting groove is provided on the bearing sleeve, and one end of the elastic foil gas bearing body is fixedly mounted in the mounting groove.

[0016] Furthermore, a gasket for locking the elastic foil gas bearing body is provided in the mounting groove.

[0017] To achieve the above technical objectives, the second aspect of the present invention discloses a transmission device, comprising the elastic foil gas bearing described in the first aspect.

[0018] The beneficial effects of the present invention are:

[0019] The elastic foil gas bearing body of the present invention has different circumferential support stiffnesses. When driven to rotate by a driving device, bearing areas with different support stiffnesses support the shaft neck. The support stiffness can be adjusted in real time, thereby improving the stability of the bearing rotor system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of an elastic foil gas bearing with adjustable support stiffness according to an embodiment of the present invention (the rotary bearing is hidden).

[0021] Figure 2 It is a schematic diagram of the three-dimensional structure of the other side of the elastic foil gas bearing with adjustable support stiffness according to an embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the structure of the elastic foil gas bearing body according to an embodiment of the present invention.

[0023] Figure 4 4 is a side view of an elastic foil gas bearing with adjustable support stiffness according to an embodiment of the present invention.

[0024] Figure 5 It is a cross-sectional view along the AA direction of an elastic foil gas bearing with adjustable support stiffness according to an embodiment of the present invention.

[0025] 1. Bearing sleeve; 11. Mounting groove; 12. Shaft shoulder; 2. Elastic foil gas bearing body; 21. Bottom arch foil; 22. Top foil; 201. First stiffness bearing area; 202. Second stiffness bearing area; 203. Third stiffness bearing area; 30. Transmission device; 3. Worm gear; 4. Worm; 5. Driving device; 6. Gasket; 7. Rotating bearing; 71. Inner ring; 72. Outer ring; 73. Ball; 8. Shaft neck. DETAILED DESCRIPTION

[0026] The elastic foil gas bearing with adjustable support stiffness and the transmission device provided by the present invention are explained and illustrated in detail below with reference to the accompanying drawings.

[0027] This embodiment specifically discloses an elastic foil gas bearing with adjustable support stiffness, such as Figure 1 and 2 As shown, it includes an elastic foil gas bearing body 2 and a driving device 5. The elastic foil gas bearing body 2 is sleeved on the outside of the shaft neck 8. The inner diameter of the elastic foil gas bearing body 2 is larger than the outer diameter of the shaft neck 8. Therefore, part of the inner wall of the elastic foil gas bearing body 2 contacts the outer wall of the shaft neck 8 for supporting the shaft neck 8.

[0028] In this embodiment, the direction close to the central axis of the elastic foil gas bearing is the inner side, and the direction away from the central axis of the elastic foil gas bearing is the outer side.

[0029] The elastic foil gas bearing body 2 includes a first stiffness bearing area 201 and a second stiffness bearing area 202 along the circumferential direction. The stiffness of the first stiffness bearing area 201 is greater than the stiffness of the second stiffness bearing area 202, so that the elastic foil gas bearing body 2 has different support stiffness along the circumferential direction.

[0030] The drive device 5 is used to rotate the elastic foil gas bearing body 2 to adjust the bearing area in contact with the shaft neck 8. This bearing area provides support force, and the rotation of the elastic foil gas bearing body 2 adjusts the support stiffness of the shaft neck 8. Rotation of the elastic foil gas bearing body 2 causes one of the first stiffness bearing area 201 and the second stiffness bearing area 202 to contact the shaft neck 8, enabling switching between two bearing areas with different stiffnesses, providing different support stiffnesses. Driven by the drive device 5, the support stiffness can be adjusted in real time, thereby improving the stability of the bearing rotor system.

[0031] In some embodiments, the elastic foil gas bearing body 2 further includes a third stiffness bearing region 203. The first stiffness bearing region 201, the second stiffness bearing region 202, and the third stiffness bearing region 203 are arranged circumferentially around the elastic foil gas bearing body 2. The stiffness of the third stiffness bearing region 203 is greater than that of the first stiffness bearing region 201. The three support regions with different stiffnesses further enhance the support stiffness selectivity and improve the stability of the bearing rotor system.

[0032] Alternatively, as Figure 1-3 As shown, the elastic foil gas bearing body 2 includes a bottom arch foil 21 and a top foil 22. The top foil 22 is arc-shaped. In this embodiment, the top foil 22 is a circle with a fracture. The top foil 22 is sleeved outside the shaft neck 8, and the top foil 22 is partially attached to the shaft neck 8; the outer side of the top foil 22 is correspondingly supported by the bottom arch foil 21, and the bottom arch foil 21 is fixedly connected to the top foil 22.

[0033] The elastic foil gas bearing body 2 has varying circumferential stiffness, including at least a second stiffness bearing zone 202 with lower stiffness and a first stiffness bearing zone 201 with higher stiffness. This can be achieved by varying the stiffness of the underlying arched foil 21 along the circumference. For example, the arches of the underlying arched foil 21 in the first stiffness bearing zone 201 may be denser than those in the second stiffness bearing zone 202, or the arches may be made of materials with different stiffnesses, or have different arch patterns.

[0034] The elastic foil gas bearing body 2 may further include a third stiffness bearing region 203, which may be disposed on a side of the second stiffness bearing region 202 away from the first stiffness bearing region 201. The stiffness of the underlying arch foil 21 in the third stiffness bearing region 203 is greater than the stiffness of the underlying arch foil 21 in the first stiffness bearing region 201. Specifically, the arch density of the underlying arch foil 21 may be different, the material stiffness of the underlying arch foil 21 may be different, or the arch patterns of the underlying arch foil 21 may be different. The denser the arches of the underlying arch foil 21, the greater the stiffness of the underlying arch foil 21.

[0035] In order to drive the bearing sleeve 1, as Figure 1 、 2As shown in Figures 4 and 5, the outer fixed sleeve of the elastic foil gas bearing body 2 of the present application is provided with a bearing sleeve 1, and the driving device 5 is connected to the bearing sleeve 1 through a transmission device 30. The transmission device 30 is used to transmit the driving force of the driving device 5. The driving device 5 drives the bearing sleeve 1 to rotate, thereby driving the elastic foil gas bearing body 2 to rotate.

[0036] Optionally, the transmission device 30 includes a worm gear 3 and a worm 4 meshing with the worm gear 3. The worm gear 3 is sleeved on the bearing sleeve 1 and fixedly connected to the bearing sleeve 1. The worm gear 3 and the bearing sleeve 1 are integrally formed or manufactured separately and then assembled. The worm 4 is fixedly connected to the driving device 5.

[0037] The driving device is a motor, which can be a drive motor or a stepper motor. The output shaft of the motor is fixedly connected to the worm 4. In order to reduce the resistance to the rotation of the bearing sleeve 1, a rotating bearing 7 is provided on the outside of the bearing sleeve 1 to reduce the rotation resistance of the bearing sleeve 1. The rotating bearing 7 is a ball bearing, a roller bearing or a tapered bearing. The number of the rotating bearing 7 can be one or two, such as Figure 1 、 2 As shown in FIG4 , a shaft shoulder 12 is provided on the bearing sleeve 1 , and two rotary bearings 7 can be provided on both sides of the shaft shoulder.

[0038] Taking ball bearings as an example, the following describes the installation method. During use, the elastic foil gas bearing of this application is mounted on a base. The inner ring 71 of the rolling bearing 7 is nested in the arc outside the bearing sleeve 1. The outer ring 72 of the rolling bearing 7 is fixed in the base. Motion is transmitted between the inner ring 71 and the outer ring 72 of the rolling bearing 7 via periodically distributed balls 73. The body of the drive device 5 is also fixed to the base.

[0039] like Figure 1 、 2 As shown in FIG5 , a mounting groove 11 is provided on the bearing sleeve 1, and one end of the elastic foil gas bearing body 2 is fixedly installed in the mounting groove 11. The mounting groove 11 is provided on the inner side of the bearing sleeve 1. In this embodiment, the mounting groove 11 is an L-shaped groove. Figure 3 As shown, one end of the bottom arch foil 21 is provided with a C-shaped bend, and the end of the top foil 22 on the same side as the bottom arch foil 21 is provided with a C-shaped bend, and the C-shaped bend is bent toward the outside of the elastic foil gas bearing body 2, and the C-shaped bend of the bottom arch foil 21 and the C-shaped bend of the top foil 22 are both arranged in the mounting groove 11.

[0040] Furthermore, to ensure secure installation, a gasket 6 is provided within the mounting groove 11 to lock the elastic foil gas bearing body 2. The gasket 6 and the C-shaped bend are locked together within the mounting groove 11, preventing the elastic foil gas bearing body 2 from shaking during operation. This method also achieves a detachable connection between the elastic foil gas bearing body 2 and the bearing sleeve 1.

[0041] The working principle of the elastic foil gas bearing of the embodiment of the present application is as follows:

[0042] When the bearing is working, the driving device 5 drives the bearing sleeve 1 to rotate, and the elastic foil gas bearing body 2 fixed on the bearing sleeve 1 rotates, and the position of the elastic foil gas bearing body 2 in contact with the shaft neck 8 changes. Since the elastic foil gas bearing body 2 has different circumferential stiffness along the circumferential direction, the support force for the shaft neck 8 is different, thereby improving the support stiffness of the shaft neck 8.

[0043] The elastic foil gas bearing of this application has the following advantages:

[0044] 1. The elastic foil gas bearing body of the present invention has different circumferential support stiffnesses. When the elastic foil gas bearing body is driven to rotate by a driving device, the bearing areas with different support stiffnesses support the shaft neck. The support stiffness can be adjusted in real time, thereby improving the stability of the bearing system.

[0045] 2. The present invention uses a worm gear as the transmission mechanism of the elastic foil gas bearing, which has a self-locking effect and is not affected by the friction force of the journal 8. The adjustment is more precise and more stable.

[0046] This embodiment also discloses a transmission device, including the elastic foil gas bearing described in the above embodiment. The transmission device can be used in the fields of aerospace, energy equipment, etc.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0049] In the description of this specification, the reference terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in an appropriate manner in any at least one embodiment or example. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and simple improvements made to the essential contents of the present invention should be included in the scope of protection of the present invention.

Claims

1. An elastic foil gas bearing with adjustable support stiffness, used for being sleeved on a matching shaft neck (8), comprising an elastic foil gas bearing body (2), wherein the elastic foil gas bearing body (2) is sleeved outside the shaft neck (8), and characterized in that: Also includes a driving device (5); The elastic foil gas bearing body (2) comprises a first stiffness bearing area (201) and a second stiffness bearing area (202) along the circumferential direction, wherein the stiffness of the first stiffness bearing area (201) is greater than the stiffness of the second stiffness bearing area (202). The elastic foil gas bearing body (2) further comprises a third stiffness bearing area (203), the first stiffness bearing area (201), the second stiffness bearing area (202) and the third stiffness bearing area (203) are arranged along the circumference of the elastic foil gas bearing body (2), the stiffness of the third stiffness bearing area (203) is greater than the stiffness of the first stiffness bearing area (201), The driving device (5) is used to drive the elastic foil gas bearing body (2) to rotate so as to adjust the bearing area in contact with the shaft neck (8). The driving device is a motor. Through the driving of the driving device (5), the support stiffness can be adjusted in real time.

2. The elastic foil gas bearing with adjustable support stiffness according to claim 1, characterized in that: The elastic foil gas bearing body (2) comprises a bottom arch foil (21) and a top foil (22); the top foil (22) is arc-shaped, and a portion of the top foil (22) is attached to the shaft neck (8); the bottom arch foil (21) is correspondingly supported on the outer side of the top foil (22).

3. The elastic foil gas bearing with adjustable support stiffness according to claim 1 or 2, characterized in that: A bearing sleeve (1) is provided on the outer fixed sleeve of the elastic foil gas bearing body (2), and the driving device (5) is connected to the bearing sleeve (1) via a transmission device (30).

4. The elastic foil gas bearing with adjustable support stiffness according to claim 3, characterized in that: The transmission device (30) comprises a worm wheel (3) and a worm (4) meshing with the worm wheel (3); the worm wheel (3) is sleeved on the bearing sleeve (1) and fixedly connected to the bearing sleeve (1).

5. The elastic foil gas bearing with adjustable support stiffness according to claim 3, characterized in that: The bearing sleeve (1) is externally sleeved with a rotating bearing (7) for reducing the rotational resistance of the bearing sleeve (1).

6. The elastic foil gas bearing with adjustable support stiffness according to claim 5, characterized in that: The rotary bearing (7) is a ball bearing, a roller bearing or a tapered bearing.

7. The elastic foil gas bearing with adjustable support stiffness according to claim 3, characterized in that: The bearing sleeve (1) is provided with a mounting groove (11), and one end of the elastic foil gas bearing body (2) is fixedly mounted in the mounting groove (11).

8. The elastic foil gas bearing with adjustable support stiffness according to claim 7, characterized in that: A gasket (6) for locking the elastic foil gas bearing body (2) is provided in the installation groove (11).

9. A transmission device, characterized in that: An elastic foil gas bearing with adjustable support stiffness comprising the support stiffness as described in any one of claims 1 to 8.

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