Flexible Foil Gas Bearing and Transmission Device

Abstract

The present invention belongs to the technical field of mechanical transmission, and discloses an elastic foil gas bearing and a transmission device. The elastic foil gas bearing is used to be mounted on a journal, and includes a foil gas bearing body and a support sleeve. The support sleeve includes an inner ring and an outer ring coaxially sleeved. A first group of connecting ribs is arranged between the inner ring and the outer ring. The first group of connecting ribs includes first tangential rib strips spaced along the circumferential direction of the inner ring. One end of the first tangential rib strip is fixedly connected to the inner ring, and the other end is fixedly connected to the outer ring. The included angle between the straight line where the length direction of the first tangential rib strip is located and the tangent direction of the connection point of the inner ring and the first tangential rib strip along the circumference of the inner ring is within 30 degrees. The transmission device includes the above-mentioned elastic foil gas bearing. The elastic foil gas bearing of the present invention has a simple structure, good heat dissipation effect, reduces the thermal expansion of each material, effectively overcomes the problems brought by thermal expansion, and realizes the operation of the bearing under high-temperature conditions.

Description

Technical Field

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

[0002] A bearing is a component that plays a role in fixing and reducing the load friction coefficient during the mechanical transmission process. Its main function is to support the mechanical rotating body to reduce the mechanical load friction coefficient of the equipment during the transmission process. In recent years, with the increasingly wide application of high-speed rotating machinery in fields such as aerospace and energy equipment, the working environment has become increasingly harsh, and the requirements for lubrication and support have gradually increased. In an oil-free lubrication system, compared with complex and expensive support methods such as electromagnetic bearings, the elastic foil gas bearing has the advantages of high rotational speed, good self-adaptability, no wear, low cost, high reliability, high temperature resistance, etc. It does not require additional oil supply and other auxiliary devices, and has a simple structure, which is one of the key technologies for oil-free lubrication.

[0003] However, under high-temperature service conditions, the elastic foil gas bearing will have problems such as thermal stress deformation of the bearing components and coating peeling caused by different expansion coefficients of various materials due to high temperature. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention innovatively provides an elastic foil gas bearing and a transmission device, which has a simple structure. Through the setting of the support sleeve and the first set of connecting ribs, the heat dissipation effect is good, the thermal expansion of each material is reduced, the problems caused by thermal expansion are effectively overcome, and the operation of the bearing under high-temperature conditions is realized.

[0005] To achieve the above technical objectives, the first aspect of the present invention discloses an elastic foil gas bearing for being installed on a journal, comprising: a foil gas bearing body and a support sleeve,

[0006] The foil gas bearing body is sleeved on the inner surface of the support sleeve;

[0007] The support sleeve includes an inner ring and an outer ring coaxially sleeved, and a first set of connecting ribs is arranged between the inner ring and the outer ring;

[0008] The first set of connecting ribs includes first tangential rib strips spaced along the circumferential direction of the inner ring. One end of the first tangential rib strip is fixedly connected to the inner ring, and the other end is fixedly connected to the outer ring. The angle between the straight line in the length direction of the first tangential rib strip and the tangent direction of the connection point of the inner ring and the first tangential rib strip along the circumference of the inner ring is within 30 degrees.

[0009] Further, the foil gas bearing body includes a bottom arch foil and a top foil;

[0010] The top foil is arc-shaped, and a plurality of the top foils are evenly distributed along the circumferential direction of the journal and are attached to the journal;

[0011] Each of the bottom arch foils is correspondingly supported below each of the top foils.

[0012] Further, a second group of connecting ribs is also arranged between the inner ring and the outer ring. The second group of connecting ribs includes second tangential rib strips that are arranged at intervals along the circumferential direction of the inner ring. One end of each second tangential rib strip is fixedly connected to the inner ring, and the other end is fixedly connected to the outer ring. The angle between the straight line in the length direction of each second tangential rib strip and the tangent direction of the inner ring at the connection point between the inner ring and the second tangential rib strip along the circumferential direction of the inner ring is within 30 degrees. The second group of connecting ribs is arranged on one side of the first group of connecting ribs along the bearing axis direction, and the second tangential rib strips and the adjacent first tangential rib strips are arranged crosswise in the axial axis direction.

[0013] Further, a third group of connecting ribs is also arranged between the inner ring and the outer ring. The third group of connecting ribs includes third tangential rib strips that are arranged at intervals along the circumferential direction of the inner ring. One end of each third tangential rib strip is fixedly connected to the inner ring, and the other end is fixedly connected to the outer ring. The angle between the straight line in the length direction of each third tangential rib strip and the tangent direction of the inner ring at the connection point between the inner ring and the third tangential rib strip along the circumferential direction of the inner ring is within 30 degrees. The third group of connecting ribs is arranged on the side of the second group of connecting ribs along the bearing axis direction that is far from the first group of connecting ribs, and the third tangential rib strips and the adjacent first tangential rib strips have the same direction.

[0014] Further, the extension line of each first tangential rib strip is tangent to the mating journal, and / or each first tangential rib strip is linear, parabolic or S-curve-shaped along the length direction, and / or each first tangential rib strip is inclined or chevron-shaped in the axial direction of the inner ring, and / or the width of each first tangential rib strip is 1-2 mm.

[0015] Further, the extension line of each second tangential rib strip is tangent to the mating journal, and / or each second tangential rib strip is linear, parabolic or S-curve-shaped along the length direction, and / or each second tangential rib strip is inclined or chevron-shaped in the axial direction of the inner ring, and / or the width of each second tangential rib strip is 1-2 mm.

[0016] Further, the extension line of each third tangential rib strip is tangent to the mating journal, and / or each third tangential rib strip is linear, parabolic or S-curve-shaped along the length direction, and / or each third tangential rib strip is inclined or chevron-shaped in the axial direction of the inner ring, and / or the width of each third tangential rib strip is 1-2 mm.

[0017] Further, vent holes are provided on the inner ring for introducing air flow between the inner ring and the outer ring.

[0018] To achieve the above technical objectives, a second aspect of the present invention discloses a transmission device, including the elastic foil gas bearing described in the first aspect above.

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

[0020] By providing tangential connection ribs between the inner ring and the outer ring, on the one hand, when heated and deformed, the tangential ribs will elongate along the length direction. However, due to the special angle design of the tangential ribs, after deformation, the inner ring will only rotate slightly around the axis, with good self-centering effect. On the other hand, the gaps between the connection ribs can form heat exchange channels, improving the heat dissipation effect of the elastic foil gas bearing. In addition, the tangential connection ribs can effectively isolate the heat transfer from the inner ring to the outer ring, reducing the thermal expansion of each material and effectively overcoming the problems brought by thermal expansion, realizing the operation of the bearing under high-temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of an elastic foil gas bearing according to an embodiment of the present invention.

[0022] Figure 2 is an isometric view of an elastic foil gas bearing according to an embodiment of the present invention.

[0023] Figure 3 is a schematic structural diagram of a support sleeve with the outer ring hidden according to another embodiment of the present invention.

[0024] Figure 4 is a schematic structural diagram of a support sleeve with the outer ring hidden according to still another embodiment of the present invention.

[0025] Figure 5 is a schematic structural diagram of a support sleeve with the outer ring hidden according to yet another embodiment of the present invention.

[0026] Figure 6 is a schematic structural diagram of a support sleeve with the outer ring hidden according to another embodiment of the present invention.

[0027] Figure 7 is a schematic structural diagram of a support sleeve with the outer ring hidden according to another embodiment of the present invention.

[0028] In the figure,

[0029] 1. Support sleeve; 11. Inner ring; 12. Outer ring; 131. First tangential rib; 132. Second tangential rib; 133. Second tangential rib; 14. Vent hole; 2. Bottom arch foil; 3. Top foil; 4. Journal. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The elastic foil gas bearing and the transmission device provided by the present invention will be explained and described in detail below with reference to the accompanying drawings of the specification.

[0031] This embodiment specifically discloses a flexible foil gas bearing for installation on a shaft diameter 4, as Figure 1-2 shown, which includes a foil gas bearing body and a support sleeve 1. The foil gas bearing body includes a bottom arch foil 2 and a top foil 3. The top foil 3 is arc-shaped, and a plurality of top foils 3 are evenly distributed along the circumference of the journal 4 and are attached to the journal 4. There is a spacing distance between adjacent top foils 3. A bottom arch foil 2 is correspondingly supported below each top foil 3. Preferably, the thickness of the top foil 3 is 0.1-1 mm, the included angle of the arc surface of the top foil 3 is 300-355°, and the diameter is 5-200 mm. The material of the top foil 32 is a superalloy GH4145 or SuS304 stainless steel and is coated with a high-temperature resistant coating, which enables the bearing to be applied in a high-temperature environment.

[0032] As Figure 3 shown, the support sleeve 1 includes an inner ring 11 and an outer ring 12 coaxially sleeved. A first group of connecting ribs is arranged between the inner ring 11 and the outer ring 12. The first group of connecting ribs includes first tangential rib strips 131 spaced along the circumferential direction of the inner ring. One end of the first tangential rib strip 131 is fixedly connected to the inner ring 11, and the other end is fixedly connected to the outer ring 12. The included angle (i.e., Figure 3 the α angle in) between the straight line where the length direction of the first tangential rib strip 131 is located and the tangent direction of the connection point between the inner ring 11 and the first tangential rib strip along the circumference of the inner ring is within 30 degrees. The length of the first tangential rib strip 131 refers to the length between the connection point of the first tangential rib strip and the inner ring 11 and the connection point with the outer ring 11. With such a setting, when the first tangential rib strips 131 spaced along the circumferential direction expand due to heat, the inner ring 11 will rotate around the axis, reducing the possibility of eccentricity and playing a better self-centering role. If the included angle (α angle) between the straight line where the length direction of the first tangential rib strip 131 is located and the tangent direction of the connection point between the inner ring and the first tangential rib strip along the circumference of the inner ring is within 15 degrees, the self-centering effect is more significant; if the extension line of the first tangential rib 11 is tangent to the mating journal 4, a relatively perfect self-centering effect can be achieved. The spacing between adjacent first tangential rib strips 131 is set as required, that is, the number of first tangential rib strips 131 included in the first group of connecting ribs is set according to the heat dissipation effect and connection strength requirements. The spacing between adjacent first tangential rib strips 131 is the same, that is, a plurality of first tangential rib strips 131 are evenly distributed along the inner ring 11 to avoid eccentricity.

[0033] In some embodiments, as Figure 4As shown, a second group of connecting ribs is also provided between the inner ring 11 and the outer ring 12. The second group of connecting ribs includes second tangential rib strips 132 that are arranged at intervals along the circumferential direction of the inner ring. One end of each second tangential rib strip 132 is fixedly connected to the inner ring 11, and the other end is fixedly connected to the outer ring 12. The angle between the straight line in the length direction of the second tangential rib strip 132 and the tangent direction of the inner ring circumference at the connection point of the inner ring 11 and the second tangential rib strip 132 is within 30 degrees. If the angle between the straight line in the length direction of the second tangential rib strip 132 and the tangent direction of the inner ring circumference at the connection point of the inner ring 11 and the second tangential rib strip 132 is within 15 degrees, the self-centering effect is more significant. If the extension line of the second tangential rib strip is tangent to the mating journal 4, a relatively perfect self-centering effect can be achieved.

[0034] The second tangential rib strips 132 are arranged on one side of the first group of connecting ribs along the bearing axis direction. The second tangential rib strips 132 and the adjacent first tangential rib strips 131 are arranged crosswise in the bearing axis direction. The number of the second tangential rib strips 132 is the same as that of the first tangential rib strips 131. By arranging the intersecting tangential rib strips, no matter which direction the journal 4 rotates, the tangential rib strips can achieve better support and self-centering effects.

[0035] In some embodiments, as Figure 5 As shown, a third group of connecting ribs is also provided between the inner ring 11 and the outer ring 12. The third group of connecting ribs includes third tangential rib strips 133 that are arranged at intervals along the circumferential direction of the inner ring. One end of each third tangential rib strip 133 is fixedly connected to the inner ring 11, and the other end is fixedly connected to the outer ring 12. The angle between the straight line in the length direction of the third tangential rib strip 132 and the tangent of the inner ring circumference at the connection point of the inner ring 11 and the third tangential rib strip 132 is within 30 degrees, and the effect is better if it is 15 degrees. The third group of connecting ribs is arranged on the side of the second group of connecting ribs along the bearing axis direction and away from the first group of connecting ribs. The directions of the third tangential rib strips 133 and the adjacent first tangential rib strips 131 are the same, that is, the projections of the third tangential rib strips 133 and the first tangential rib strips 131 along the bearing axis direction coincide. The third tangential rib strips 133 and the adjacent second tangential rib strips 132 are also arranged crosswise in the bearing axis direction. If the extension line of the third tangential rib strip 133 is tangent to the mating journal 4, a relatively perfect self-centering effect can be achieved.

[0036] In the above embodiments, the connection manner between the tangential rib strips and the inner ring 11 and the outer ring 12 can be welding, snap connection, or plug connection.

[0037] In this application, by providing multiple groups of tangential connecting ribs, especially the intersecting tangential connecting ribs, on the one hand, the support strength is improved, and on the other hand, the heat dissipation effect is improved.

[0038] In some embodiments, asFigure 6 As shown, in order to improve the heat dissipation effect of the gaps between the ribs, vent holes 14 can be formed in the inner ring 11. Preferably, the vent holes 14 are arranged in the gaps between adjacent tangential ribs. The vent holes 14 can be circular, triangular, rectangular or other shapes, as long as they can introduce the air flow in the inner ring 11 into the space between the inner ring 11 and the outer ring 12. The size of the vent holes can be selected according to the actual situation.

[0039] In some embodiments, as Figure 6 - Figure 7 shown, the first tangential rib 131, the second tangential rib 132, or the third tangential rib 133 is in a herringbone shape ( Figure 6 as shown) or a skew line shape ( Figure 7 as shown) in the axial direction of the inner ring 11, which can better guide the air flow to flow along the surface of the ribs, thereby improving the heat dissipation effect.

[0040] As Figure 6 shown, when the tangential rib is in a herringbone shape in the axial direction of the inner ring 11, the vent hole 14 can be arranged at the middle position of the herringbone shape, which is beneficial to the flow of the high-temperature air flow along the oblique line from the higher side to the lower side.

[0041] As Figure 7 shown, when the tangential rib is in a skew line shape in the axial direction of the inner ring 11, the vent hole 14 can be arranged on the higher side of the skew line shape, which is beneficial to the flow of the high-temperature air flow along the oblique line from the higher side to the lower side.

[0042] In this application, by arranging vent holes on the inner ring, the air flow inside the bearing can be introduced from the inner ring into the space between the inner ring and the outer ring and the gaps between the tangential connecting ribs, thereby better improving the heat dissipation effect;. The design of the special cross-sectional shape of the tangential connecting ribs helps to form an air flow channel and improve the heat dissipation effect.

[0043] Optionally, the first tangential rib 131 is linear, parabolic or S-curve shaped along its length direction, and the width of the first tangential rib 131 is 1-2 mm. The second tangential rib 132 is linear, parabolic or S-curve shaped along its length direction, and the width of the second tangential rib 132 is 1-2 mm. The third tangential rib 133 is linear, parabolic or S-curve shaped along its length direction, and the width of the third tangential rib is 1-2 mm. The specific shape and width of the tangential rib along the length direction are set according to needs, providing a more abundant design scheme, as long as the heat dissipation effect, the support effect are ensured and no eccentricity occurs.

[0044] The working principle of the flexible foil gas bearing in the embodiments of this application:

[0045] With the increase in rotational speed, the rotational effect of the journal 4 forms a dynamic pressure with a gradient in the wedge-shaped space between the journal 4 and the top foil 3, causing the journal 4 to completely separate from the contact with the top foil 3, forming a stable lubricating gas film and reaching the gas film suspension working state. When the bearing operates in a high-temperature gas flow, on the one hand, the first tangential rib 131, the second tangential rib 132, and the third tangential rib 133 can effectively isolate the heat flow. On the other hand, the gas flow channel between the inner ring 11 and the outer ring 12 allows the high-temperature gas flow to pass through quickly. On the third hand, the deformation of the first tangential rib 131, the second tangential rib 132, and the third tangential rib 133 keeps the geometric center of the bearing basically unchanged all the time, without affecting the normal load-bearing of the bearing. In addition, the design of the cross-sectional shapes of the first tangential rib 131, the second tangential rib 132, and the third tangential rib 133 and the vent holes 14 provided on the inner ring 11 are all conducive to the rapid passage of the high-temperature gas flow and rapid heat dissipation, thereby reducing the thermal expansion of each material and effectively overcoming problems such as thermal stress deformation and coating peeling of the bearing components caused by thermal expansion, realizing the operation of the bearing under high-temperature conditions.

[0046] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the 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 cannot be understood as a limitation to the present invention.

[0047] In the present invention, unless otherwise clearly specified and defined, the terms "mounted", "connected", "connected to", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the description of this specification, the descriptions referring to terms such as "this embodiment", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0049] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and simple improvements made to the substantial content of the present invention shall be included within the protection scope of the present invention.

Claims

1. An elastic foil gas bearing for mounting on a journal (4), characterized in that: include: Foil gas bearing body and support sleeve (1), The foil gas bearing body is sleeved on the inner surface of the support sleeve (1); The support sleeve (1) comprises an inner ring (11) and an outer ring (12) which are coaxially sleeved, and a first group of connecting ribs is arranged between the inner ring (11) and the outer ring (12); The first group of connecting ribs comprises first tangential ribs (131) arranged at intervals along the circumferential direction of the inner ring, one end of the first tangential rib (131) is fixedly connected to the inner ring (11), and the other end is fixedly connected to the outer ring (12), an angle between a straight line where the length direction of the first tangential rib (131) is located and a tangent line along the circumference of the inner ring at a connection point between the inner ring (11) and the first tangential rib (131) is within 30 degrees, and an extension line of the first tangential rib (131) is tangent to a matching shaft neck (4); The inner ring is provided with a vent hole (14), which is arranged in the gap between adjacent tangential ribs and is used to introduce airflow between the inner ring (11) and the outer ring (12). The first tangential rib (131) is in an oblique line shape or a herringbone shape in the axial direction of the inner ring (11). When the first tangential rib (131) is in an oblique line shape in the axial direction of the inner ring (11), the vent hole (14) is arranged on the higher side of the oblique line shape. When the first tangential rib (131) is in a herringbone shape in the axial direction of the inner ring (11), the vent hole (14) is arranged in the middle position of the herringbone shape.

2. The elastic foil gas bearing according to claim 1, characterized in that: The foil gas bearing body comprises a bottom arch foil (2) and a top foil (3); The top foil (3) is in an arc shape, and a plurality of the top foils (3) are evenly distributed along the circumference of the shaft neck (4) and are attached to the shaft neck (4); The bottom arch foil (2) is supported correspondingly below each top foil (3).

3. The elastic foil gas bearing according to claim 1, characterized in that: A second group of connecting ribs is also arranged between the inner ring (11) and the outer ring (12), and the second group of connecting ribs includes second tangential ribs (132) arranged at intervals along the circumferential direction of the inner ring, one end of the second tangential rib (132) is fixedly connected to the inner ring (11), and the other end is fixedly connected to the outer ring (12), and the angle between the straight line where the length direction of the second tangential rib (132) is located and the tangent line along the circumference of the inner ring at the connection point between the inner ring (11) and the second tangential rib (132) is within 30 degrees, and the second tangential rib (132) is arranged on one side of the first group of connecting ribs along the bearing axis direction, and the second tangential rib (132) and the adjacent first tangential rib (131) are arranged crosswise in the direction of the bearing axis.

4. The elastic foil gas bearing according to claim 1, characterized in that: A third group of connecting ribs is also arranged between the inner ring (11) and the outer ring (12), and the third group of connecting ribs includes third tangential ribs (133) arranged at intervals along the circumferential direction of the inner ring, one end of the third tangential rib (133) is fixedly connected to the inner ring (11), and the other end is fixedly connected to the outer ring (12), the angle between the straight line where the length direction of the third tangential rib (132) is located and the tangent line of the connection point between the inner ring (11) and the third tangential rib (132) along the circumference of the inner ring is within 30 degrees, the third group of connecting ribs is arranged on the side of the second group of connecting ribs away from the first group of connecting ribs along the bearing axis direction, and the third tangential rib (133) and the adjacent first tangential rib (131) are in the same direction.

5. The elastic foil gas bearing according to claim 1, characterized in that: The first tangential rib (131) is in a straight line, a parabola or an S-curve shape along the length direction, and / or the width of the first tangential rib (131) is 1 to 2 mm.

6. The elastic foil gas bearing according to claim 3, characterized in that: The extension line of the second tangential rib (132) is tangent to the matching shaft neck (4), and / or the second tangential rib (132) is straight, parabolic or S-curved along the length direction, and / or the second tangential rib (132) is oblique or herringbone in the axial direction of the inner ring (11), and / or the width of the second tangential rib (132) is 1 to 2 mm.

7. The elastic foil gas bearing according to claim 4, characterized in that: The extension line of the third tangential rib (133) is tangent to the matching shaft neck (4), and / or the third tangential rib (133) is straight, parabolic or S-curved along the length direction, and / or the third tangential rib (133) is oblique or herringbone in the axial direction of the inner ring (11), and / or the width of the third tangential rib (133) is 1 to 2 mm.

8. A transmission device, characterized in that: The invention comprises the elastic foil gas bearing as described in any one of claims 1 to 7.

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