Aerodynamic bearing and bearing arrangement comprising two aerodynamic bearings designed as radial bearings

Abstract

The invention relates to an aerodynamic bearing (1) for axial and / or radial mounting of a shaft (2) of a turbocompressor extending along an axis of rotation (A), the aerodynamic bearing (1) having a first bearing part (10), which can be referred to as a rotor, and a second bearing part (20), which can be referred to as a stator, relative to which the first bearing part (10) can be rotated about the axis of rotation (A), the first bearing part (10) and / or the second bearing part (20) have / has a bearing surface (11, 21), each facing the other bearing part (10, 20), on which a cushion (3) for aerodynamic bearing can be formed between the bearing parts (10, 20), the bearing surface (11, 21) having a plurality of recesses (12), each recess (12) following a predetermined longitudinal course (13) on the bearing surface (11, 21) and being arranged in a predetermined pattern, the longitudinal course (13) has two sections (13A, 13B) which transition to each other at an apex (14), the apex (14) lying on an apex line (S) which moves parallel to a centre line (M) of the bearing surface (11, 21) such that the longitudinal course (13) is asymmetrical to the centre line (M).

Description

Technical Field

[0001] The invention relates to an aerodynamic bearing for axially and / or radially supporting a shaft extending along the rotation axis of a turbocompressor, in particular a high-speed turbocompressor, and to a bearing arrangement having two aerodynamic bearings configured as radial bearings. Background Art

[0002] Aerodynamic bearings, also known as gas or air bearings, are already known in the art. A gas cushion or air cushion is formed between two bearing partners or between the bearing surfaces provided thereby, acting as a lubricant, allowing the bearing partners or bearing components to rotate relative to each other essentially without contact or friction.

[0003] Furthermore, in order to increase the stability of the bearing or the maximum achievable speed of the bearing, it has long been known to introduce recesses in the bearing surface, by means of which the gas cushion or air cushion remains uniform and elastic, especially at high speeds, thereby maintaining the required pressure distribution in the bearing even at high speeds or when the bearing surface is subjected to high loads.

[0004] For example, in the case of axial support, the recesses may be spiral-shaped, while in the case of radial support, the recesses may be arrow-shaped and accordingly arranged in a herringbone pattern so that adjacent recesses engage one another without contact.

[0005] Here, the prior art provides that the recesses are arranged symmetrically with respect to the center line of each bearing surface dividing the bearing component. In particular, in the case of a herringbone pattern arrangement, the apex of the arrow-shaped groove is located on the center line.

[0006] Therefore, the main bearing point or main support area determined by the pressure distribution on the bearing surface is located on the center line.

[0007] If a plurality of such aerodynamic bearings configured as radial bearings are used in a radial bearing arrangement, the spacing between the center lines along the rotational axis of the supported shaft results in a bearing spacing that may not be sufficient to achieve the desired stability. Therefore, according to prior art solutions, the bearing spacing, i.e., the spacing between the center lines, must be increased by arranging the bearing surfaces or radial bearings further apart in the axial direction. This results in an increase in the installation space and is not always feasible in terms of design. Summary of the Invention

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to overcome the above-mentioned disadvantages and to provide an aerodynamic bearing which is easy to manufacture and which can increase the stability of the bearing arrangement in a simple manner.

[0009] This object is achieved by the combination of features described in patent claim 1 .

[0010] According to the present invention, an aerodynamic bearing is provided for axially and / or radially supporting a shaft extending along a rotational axis of a turbo compressor, in particular a high-speed turbo compressor. The aerodynamic bearing is preferably configured for radial support, i.e., configured as a radial bearing. Axial, radial, and diagonal compressors can be classified as turbo compressors. Thus, the turbo compressor in this example can also be an axial compressor, a radial compressor, or a diagonal compressor. The aerodynamic bearing has a first bearing member, which can be referred to as a rotor, and a second bearing member, which can be referred to as a stator. The second bearing member is rotatable relative to the first bearing member about the rotational axis. The first bearing member and / or the second bearing member has a bearing surface facing the respective other bearing member and as described below, on which an air cushion or an air film can be formed between the bearing members for aerodynamic support. One or, if necessary, a plurality of bearing surfaces each have a plurality of recesses, and each recess (12) follows a predetermined longitudinal direction on or along the bearing surface and is arranged in a predetermined pattern. The longitudinal direction has two sections, which transition to each other at a vertex and preferably at an acute angle.

[0011] In this case, according to the present invention, the vertex is located on a vertex line, and the vertex line moves parallel to the center line of the support surface, so that the vertex line also extends parallel to and spaced from the center line. Thus, the longitudinal direction is asymmetric with respect to the center line.

[0012] Furthermore, each section has a predetermined angle with respect to the vertex line, where the first angle of the first section is equal to the second angle of the second section, or the angle of the first section is not equal to the angle of the second section.

[0013] Since the main bearing points or the main support regions of each bearing surface or the bearing are determined by one or more vertices of the recesses, the main bearing points or the main support regions are transferred from the center line to the vertex line, so that the pressure pads generated on the bearing surface are also asymmetrically configured, and the bearing is supported outside the center line.

[0014] Therefore, the pressure pads are configured in such a way that the forces acting on the bearing outside the center line are optimally supported without moving the bearing or the bearing surface.

[0015] Preferably, each section extends linearly when projected onto a plane and / or unfolded on the side surface of the shaft, and the longitudinal direction preferably has an arrow shape.

[0016] Here, due to their predetermined longitudinal direction, the recesses can also be referred to as channels or grooves or radial grooves, for example, and preferably extend radially into the shaft.

[0017] In addition, the recesses can be arranged in a herringbone pattern so as to overlap in the circumferential direction. In particular, the tips formed by the recesses can be in contact with the regions spanned by the adjacent recesses.

[0018] Here, the width of each recess is preferably measured orthogonally to its longitudinal direction, or parallel to the center line or the apex line, but does not necessarily have to be constant. Instead, on the bearing surface of each section, each recess may have a constant or variable width in its respective longitudinal direction, which in turn has a positive impact on optimizing the air cushion, especially at high rotational speeds.

[0019] Even if the width of each section should be constant or uniform, the width of the first section and the width of the second section may be different.

[0020] Preferably, the aerodynamic bearing is configured as a radial bearing for radially supporting a shaft extending along the axis of rotation of the turbo compressor, wherein the first bearing member is particularly integrally formed with the shaft.

[0021] On the other hand, a bearing device according to the present invention has two aerodynamic bearings according to the present invention configured as radial bearings. The first bearing members of the first radial bearing and the second radial bearing are spaced apart from each other on the shaft or along the axis of rotation, so that there is a distance that can be referred to as the actual bearing spacing between the center lines of the two bearing surfaces along the axis of rotation. The apex lines of the respective bearings are respectively arranged on the side of their respective center lines facing away from the other bearing member, so that there is a distance that can be referred to as the virtual bearing spacing between the apex lines of the two bearing surfaces along the axis of rotation, and this distance is greater than the actual bearing spacing.

[0022] This means that without moving the bearings, the spacing or distance between the main support areas of the two bearings determined by the apex lines can be increased, and the support provided by the two radial bearings can be improved.

[0023] Preferably, the two radial bearings of the two first bearing members or at least the bearing surfaces are mirror-symmetrical or point-symmetrical with respect to a symmetry plane that is centered between the radial bearings and orthogonal to the axis of rotation.

[0024] As long as it is technically feasible and does not conflict with each other, the features disclosed above can be combined as needed. Description of the Drawings

[0025] Other advantageous embodiments of the present invention are described in the dependent claims or are described in more detail below in conjunction with the description of the preferred embodiments of the present invention with reference to the drawings. Among them:

[0026] Figure 1 Showing a bearing device including two aerodynamic bearings. Detailed Description

[0027] The figure is an exemplary schematic diagram depicting two aerodynamic bearings 1, which form a bearing arrangement 4 for a shaft 2. The two aerodynamic bearings 1 are configured for the radial support of a shaft 2 extending along a rotational axis A and can thus be referred to as radial bearings 1 respectively. The shown bearing arrangement 4 is particularly provided for a high-speed turbo compressor.

[0028] Accordingly, each radial bearing 1 has two bearing mating parts or two bearing components 10, 20. The first bearing component 10 is respectively configured as a rotor integral with the shaft 2 and can thus rotate about the rotational axis A. The second bearing component 20 is configured as a stator and completely surrounds the respective first bearing component 10 in an annular shape in the circumferential direction U. Thus, Figure 1 The second bearing component 20 shown in a mid-sectional view is substantially equivalent to a hollow cylinder, and they can also be connected to each other through an intermediate member, or directly connected to each other, or integrally formed.

[0029] The bearing components 10, 20 of each bearing 1 each have bearing surfaces 11, 21 facing each other, so that when the first bearing component 10 rotates, an air cushion or air film 3 is formed between the bearing surfaces 11, 21 as a lubricant or sliding agent for the bearing.

[0030] In order to achieve an optimal pressure distribution of the lubricating medium, i.e., gas or air, on the bearing surface 11 of the first bearing component 10 or the rotor bearing surface 11 of the rotor 10, even at high speeds of operation, a large number of recesses 12 are provided on the first bearing surface 11, and each recess extends arrow-shaped along a longitudinal direction 13. Accordingly, the corresponding same longitudinal direction 13 of each recess 12 has two linear sections 13A, 13B, which are connected to each other through a kink or vertex 14.

[0031] From Figure 1 it can be clearly seen that the arrow-shaped recesses 12 overlap in the circumferential direction U, thus forming a pattern similar to a herringbone pattern.

[0032] Although the width B of the recesses 12 shown here is constant, except for the edge or kink regions, the width B can also vary along the longitudinal direction 13 of each recess 12.

[0033] According to the present invention, in each case, the kink or vertex 14 is not just centered on the bearing surface 11 and located on a center line M extending orthogonally to the rotational axis A, but is located on a vertex line S shifted parallel thereto, so that the recesses 12 or the pattern formed by them is asymmetric with respect to the center line M.

[0034] Accordingly, the main support area formed by the pressure pad and accordingly affected by the groove 12 for supporting a radial load or a radial support is no longer located on the center line M, but eccentrically on the apex line S, which is particularly advantageous in the bearing arrangement 4 shown, since the two radial bearings 1 are mirror images with respect to the symmetry plane E, resulting in a virtual bearing spacing D2 being greater than the actual bearing spacing D1. This results in a higher stability and smoother operation of the shaft 2 supported by the bearings 1, which is particularly beneficial for high rotational speeds.

[0035] The invention is not limited to the above preferred embodiments. On the contrary, the invention can also have many variations, which also utilize the above embodiments that are substantially different from the present invention.

Claims

1. An aerodynamic bearing (1) for axially and / or radially supporting a shaft (2) extending along a rotational axis (A) of a turbo compressor, Among them, The aerodynamic bearing (1) has a first bearing member (10) which can be referred to as a rotor and a second bearing member (20) which can be referred to as a stator. The first bearing member (10) is rotatable about the rotational axis (A) relative to the second bearing member. Wherein, the first bearing member (10) and / or the second bearing member (20) has bearing surfaces (11, 21) which face each other's bearing members (10, 20) respectively, and an air cushion (3) for aerodynamic support can be formed between the bearing members (10, 20) on the bearing surfaces. Wherein, the bearing surfaces (11, 21) have a plurality of recesses (12), and each recess (12) follows a predetermined longitudinal direction (13) on the bearing surfaces (11, 21) and is arranged in a predetermined pattern. Wherein, the longitudinal direction (13) has two sections (13A, 13B), and the two sections transition to each other at a vertex (14). Wherein, the vertex (14) is located on a vertex line (S), and the vertex line moves parallel to the center line (M) of the support surface (11, 21), so that the longitudinal direction (13) is asymmetric with respect to the center line (M). Wherein, the sections (13A, 13B) have a predetermined angle with the vertex line (S). And wherein, the first angle of the first section (13A) is equal to the second angle of the second section (13B), or Wherein, the angle of the first section (13A) is not equal to the angle of the second section (13B).

2. The aerodynamic bearing according to claim 1, Among them, The sections (13A, 13B) extend linearly when projected onto a plane and / or when unfolded on the side surface of the shaft (2), and the longitudinal direction (13) is arrow-shaped.

3. The aerodynamic bearing according to any one of the preceding claims, Among them, The recesses (12) are arranged in a herringbone pattern and overlap in the circumferential direction (U).

4. The aerodynamic bearing according to any one of the preceding claims, Among them, The recesses (12) have a constant or variable width (B) on the respective longitudinal directions (13) of the bearing surfaces (11, 21) of each section.

5. The aerodynamic bearing according to the previous claim, Among them, The width (B) of the first section (13A) and the width (B) of the second section (13B) are different.

6. The aerodynamic bearing according to any one of the preceding claims, Among them, The aerodynamic bearing (1) is configured as a radial bearing for radially supporting a shaft (2) extending along the rotational axis (A) of a turbo compressor, and the first bearing member (10) is integrally formed with the shaft (2) in particular.

7. A bearing device (4) having two aerodynamic bearings (1) according to the preceding claims configured as radial bearings. Among them, The first bearing components (10) of the two radial bearings (1) on the shaft (2) are spaced apart from each other, and there is a distance along the rotational axis (A) between the centerlines (M) of the two bearing surfaces (11) that can be referred to as the actual bearing spacing (D1), and wherein the vertex lines (S) are respectively arranged on the side of each centerline (M) facing away from the respective other first bearing component (10), such that there is a distance along the rotational axis (A) between the vertex lines (S) of the two bearing surfaces (11) that can be referred to as the virtual bearing spacing (D2), and the virtual bearing spacing is greater than the actual bearing spacing (D1).

8. The bearing arrangement according to the preceding claim, Among them, the radial bearings (1) or at least the bearing surfaces (11) of the two first bearing components (10) are mirror-symmetrical with respect to a symmetry plane (E) that is centered between the radial bearings (1) and orthogonal to the rotational axis (A).

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