GB2520825A

GB2520825A - Air vane wheel for conveying air having an air bearing and radial compressor having an air vane wheel

Info

Publication number: GB2520825A
Application number: GB1418423.8A
Authority: GB
Inventors: Steffen Derhardt; Anton Dukart; Andreas Vogt
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2013-10-17
Filing date: 2014-10-17
Publication date: 2015-06-03
Anticipated expiration: 2034-10-17
Also published as: GB2520825B; FR3012185B1; GB201418423D0; FR3012185A1; DE102013221119A1

Abstract

A vane wheel 10 for conveying and/or compressing air comprising at least one vane 20 shaped to form with a housing 40 encompassing the vane wheel a radial and/or axial air bearing 110. Preferably an extension surface 70 extends the vane in a circumferential direction 80, connects the vane to an adjacent vane 120 and forms a gap 60 with the housing which narrows opposite to a direction of rotation 50 of the wheel. The extension surface may form with the housing a volume 100 separate from spaces 90 between adjacent vanes. The wheel may form the turbine or compressor wheel of a radial compressor. Also claimed is a method of supporting a vane wheel by an air bearing formed on the outer circumference of the wheel. The air bearing provides a cushion of air for supporting the wheel which removes the need for an additional mechanical bearing, thereby saving manufacturing costs and weight.

Description

Description Title

Air vane wheel for conveying air having an air bearing and radial compressor having an air vane wheel

Prior art

The present invention relates to an air vane wheel for conveying and/or for compressing air. Furthermore, the present invention relates to a radial compressor having the air vane wheel according to the invention and to a method for supporting an air vane wheel.

DE 000008328100 Ui describes a turbocharger having a rotor, the rotor being supported by an axial air bearing.

Disclosure of the invention

Advantages of the invention The air vane wheel according to the invention having the features of the independent claim has, over the prior art, the advantage that a device for conveying and/or for compressing air having the air vane wheel according to the invention can be realised particularly inexpensively and with particularly low weight. Owing to the fact that at least one air vane of the air vane wheel is shaped at a radial end to form with a housing encompassing the air vane wheel an air bearing for supporting the air vane wheel, an additional mechanical bearing for supporting the air vane wheel can be dispensed with. Dispensing with an additional mechanical bearing for supporting the air vane wheel makes it possible to save costs and weight.

Particularly advantageously, the air vane can be shaped at a radial end in such a manner that with the encompassing housing a radial air bearing or an axial air bearing can be formed. Furthermore particularly advantageously, the air vane wheel can be shaped in such a manner that with the encompassing housing an air bearing is formed by the shaping of the air vane wheel, the air bearing serving at the same time as a radial air bearing and as an axial air bearing. The air bearing can thus take up forces in the axial direction and also in the radial direction.

An air vane in the context of the present description is a workpiece shaped in such a manner that upon a rotation of the air vane relative to the surrounding air, the air can be moved, displaced and/or accelerated particularly efficiently in one or more directions.

An air vane wheel in the context of the present description is an arrangement of at least one, in particular of a plurality of, air vanes on a wheel. Upon a rotation of the wheel, the air vanes are moved relative to the surrounding air and displace the air along an axis of rotation of the air vane wheel and/or in a radial direction of the air vane wheel.

By a conveying of air in the context of the present application there is understood the moving of air along a predetermined direction.

A radial end of an air vane in the context of the present application is the end lying opposite the place at which the air vane is fastened to the wheel when the air vane is mounted on a wheel to form an air vane wheel.

By a housing encompassing the air vane wheel in the context of the present application there is understood a housing that encompasses the air vanes of the air vane wheel at their radial end, in particular with a diameter greater than a diameter defined by the radial ends of the air vanes.

By a radial bearing there is understood a support of a wheel, the support being able to take up forces in the radial direction. By an axial bearing there is understood a support, the support being able to take up forces in the axial direction.

By a radial air bearing there is understood a radial bearing, the radial air bearing providing an air-cushioned support upon movement of the wheel supported by the radial air bearing.

By an axial air bearing there is understood an axial bearing, the axial air bearing providing an air-cushioned support upon movement of the wheel supported by the axial air bearing.

Advantageous developments and improvements are possible through the measures recited in the dependent claims.

In an advantageous development, the at least one air vane of the air vane wheel is configured to form with the housing encompassing the air vane wheel at the radial end of the air vane a gap narrowing opposite to a direction of rotation of the air vane wheel. Such a radial air bearing of the air vane wheel is particularly efficient and of particularly low friction, since a narrowing gap enables a particularly good construction of an air bearing.

By a narrowing gap there is to be understood a gap which has a greater opening at one side of the gap than at an opposite side of the gap.

By a direction of rotation of the air vane wheel there is to be understood that direction in which the air vane wheel conveys and/or compresses air.

Advantageously, the at least one air vane is configured to form the narrowing gap by an extension surface, the extension surface extending the air vane in a circumferential direction of the air vane wheel opposite to the direction of rotation of the air vane wheel. An air bearing realised via the extension surface of the air vane wheel is particularly load-bearing, since the extension surface of the air vane can create a particularly stable and load-bearing air cushion for supporting the air vane wheel.

By an extension surface of an air vane in the context of the present description there is to be understood a surface which, directly following the air vane, extends the air vane by a predetermined surface in a predetermined direction and/or in a plurality of predetermined directions.

By a circumferential direction of the air vane wheel there is to be understood a direction along the circumference of the air vane wheel.

A configuration of the air vane in such a manner that the extension surface of the air vane is extended in the circumferential direction of the air vane wheel at least as far as an adjacent air vane, has the advantage that a radial air bearing of the air vane can be of particularly stable and smooth-running design. The extension of the extension surface of the air vane as far as the adjacent air vane allows the creation of a closed surface on the circumference of the air vane wheel and thus the creation of a particularly stable air cushion of the radial air bearing.

By a second air vane adjacent to a first air vane there is to be understood that second air vane which, in the case of an arrangement of the first air vane and of the second air vane on the air vane wheel, lies directly beside the first air vane, i.e. directly follows along the circumference of the air vane wheel of the first air vane.

In an advantageous development of the air vane wheel, the extension surface of the air vane is connected to the adjacent air vane. A radial air bearing of the air vane wheel formed with the air vane wheel is particularly load-bearing in the stated development, since the connection of the extension surface to the adjacent air vane forms a particularly efficient running surface of the radial air bearing.

A device having the air vane wheel according to the invention and having a housing encompassing the air vane wheel can be produced in an advantageous manner particularly easily and cost-effectively.

Advantageously, the device has an air bearing for supporting the air vane wheel, the air bearing being formed by the air vane wheel with the housing.

Advantageously, such a device can be used for conveying and/or for compressing air, the device being realisable so as to be particularly smooth-running, since an air bearing causes only low vibrations. Particularly advantageously, the air bearing is formed as a radial air bearing or as an axial air bearing. In a particularly advantageous development, the air bearing is formed as a radial air bearing and additionally as an axial air bearing. The air bearing can thus ensure a support of the air vane wheel in the radial direction and in the axial direction at the same time and thus enables the particularly compact and lightweight construction of an air vane wheel with housing.

In an advantageous development of the device, the extension surfaces of the air vanes form with the housing a volume, the volume being separated from spaces between the air vanes. An air bearing between air vane wheel and housing is realisable particularly efficiently and the air vane wheel with housing can be used particularly well for conveying andlor for compressing air, since the volume forming the radial air bearing and the spaces of the air vane wheel used for conveying and/or for compressing are separated from each other and do not mutually affect each other in their function.

By forming the device according to the invention as a radial compressor, the air vane wheel being formed as a turbine wheel or as a compressor wheel of the radial compressor, there is provided a radial compressor which is realisable particularly easily and cost-effectively and has a particularly high smoothness of running.

One or more of the air vanes can have a friction-reducing coating on a side of the extension surface facing the encompassing housing. For example, a layer of graphite can be applied. Furthermore advantageously, the encompassing housing has a further friction-reducing coating on a side opposite the air vane.

A start of a rotational movement of the air vane wheel relative to the housing encompassing the air vane wheel can thus occur with particularly low wear, since on the start of the movement the axial air bearing and/or the radial air bearing are not yet particularly load-bearing.

Further advantages emerge from the following description of embodiments with reference to the figures.

Brief description of the drawings

Exemplary embodiments of the invention are illustrated in the drawings and explained in more detail in the following description.

In the drawings: Figure 1 shows an air vane wheel having air vanes for conveying and/or for compressing air, the air vanes being shaped at the radial end of the air vane to form with an encompassing housing an air bearing.

Figure 2 shows a sectional drawing of the air vane wheel illustrated in Figure 1.

Figure 3 shows a sectional drawing of a development of the air vane wheel illustrated in Figure 1, the extension surfaces of the air vane being connected to the respectively adjacent air vane.

Embodiments of the invention In the following there is illustrated an air vane wheel for conveying and/or for compressing air, at least one air vane of the air vane wheel being shaped at a radial end to form with a housing encompassing the air vane wheel an air bearing. Furthermore, there is shown a radial compressor having an air vane wheel, in particular having an air vane wheel with housing, the air vane wheel being formed as a turbine wheel and/or as a compressor wheel of the radial compressor.

Figure 1 shows an air vane wheel having air vanes for conveying and/or for compressing air, the air vanes being shaped at the radial end of the air vane to form with an encompassing housing a radial air bearing.

In Figure 1 there is illustrated an air vane wheel 10 for conveying and/or for compressing air. There is illustrated the air vane wheel 10, a first air vane 20 with a radial end of the first air vane 30, and also a second air vane 120 with a radial end of the second air vane 130. There are also illustrated further air vanes with further radial ends. Figure 1 further shows a direction of rotation of the air vane wheel and also an extension surface of the first air vane 70 and an extension surface of the second air vane 170. There is also illustrated a circumferential direction 80 of the air vane wheel 10.

The first air vane 20 and the second air vane 120 are fastened to the hub 180 by an end lying opposite the radial end of the first air vane 30 and by an end lying opposite the radial end of the second air vane 130. The first air vane 20 is extended at the radial end of the first air vane 30 by the extension surface of the first air vane 70. The extension surface of the first air vane 70 is a direct extension of the first air vane 20 along the circumferential direction 80 of the air vane wheel 10.

Upon an operation of the air vane wheel 10 for conveying and/or for compressing air, the air vane wheel is rotated along the direction of rotation 50.

In the present exemplary embodiment, air is caught at an upper end of the first a vane 20 and guided to a lower end of the first vane 20, the air exiting from the air vane wheel in the radial direction. The air exits radially from the outlet opening 200. The extension surface of the first air vane 70 extends the first air vane 20 along the circumferential direction 80 in an opposite direction to the direction of rotation 50. The second air vane 120 is fastened to the hub 180 adjacently to the first air vane 20. The adjacent fastening means that, after the first air vane 20 has been fastened to the hub 180, the second air vane 120 follows as the next air vane on the hub 180 along the circumferential direction 80. The first air vane and the second air vane 120 are thus adjacent and the second air vane 120 is the air vane adjacent to the first air vane 20. The extension surface of the first air vane 70 is extended along the circumferential direction 80 in the opposite direction to the direction of rotation 50 as far as the radial end of the second air vane 130. In a further exemplary embodiment, the extension surface of the first air vane and/or the extension surface of the second air vane can be extended to a greater or lesser extent along the circumferential direction 80.

Upon a rotation of the air vane wheel 10 along the direction of rotation 50, air from the surroundings is caught at the upper side of the air vane wheel 10 and conveyed by the first air vane and by the further air vanes to the lower end of the air vane wheel 10, where the air exits in the radial direction. Upon a movement of the air vane wheel 10 along the direction of rotation 50, air which is situated in the vicinity of the extension surface of the first air vane 70 and is further away from the hub 180 of the air vane wheel 10 than the radial end of the first air vane is pushed away from the air vane wheel 10 radially outwards. Through the movement of the extension surface of the first air vane 70 and/or of the extension surface of the second air vane 170, the air which is initially situated near the radial end of the first air vane 30 and/or near the radial end of the second air vane 130 is pushed away from the air vane wheel 10 in the radial direction by the extension surface of the air vane, from the radial end of the air vane along the extension surface of the first air vane and/or along the extension surface of the second air vane 170.

Through the pushing-away of the air in the radial direction, the air vane wheel 10 can form with an encompassing housing a radial air bearing for supporting the air vane wheel 10. The air vane wheel 10 is thus supported by a radial air bearing, the radial air bearing being formed on an outer circumference of the air vane wheel, which circumference is formed by air vanes of the air vane wheel. In the embodiment illustrated in Figure 1, the first air vane 20 is shaped in such a manner that the air vane 20 changes from a fastening to the hub 180 into a fastening to an axial surface 190. The radial end of the first air vane 30 accordingly runs partly parallel to the hub 180 and partly perpendicular to the hub 180. The radial end of the first air vane 30 furthermore has a transition region between the parallel course and the perpendicular course.

The extension surface of the first air vane 70 follows the radial end of the first air vane. A first part of the extension surface of the first air vane 70 therefore lies largely parallel to the surface of the hub 180. A further part of the extension surface lies largely perpendicular to the hub 180. The first part of the extension surface is configured to push air away from the hub 180 in the radial direction.

The first part of the extension surface can thus form with an encompassing housing a radial air bearing. The second part of the extension surface is configured to push air away from the extension surface in the axial direction. The second part of the extension surface can thus form with an encompassing housing an axial air bearing. In the exemplary embodiment illustrated in Figure 1, a radial air bearing and at the same time an axial air bearing can thus be formed by the extension surface of the first air vane and additionally by the extension surface of the further air vanes.

Figure 2 shows a sectional drawing of the air vane wheel 10 illustrated in Figure 1.

Features which are the same as those in Figure 1 are provided with the same reference numerals in Figure 2. Figure 2 furthermore shows a housing 40 encompassing the air vane wheel 10 and also a narrowing gap 60 and a radial air bearing 110.

The housing 40 encompassing the air vane wheel 10 encompasses the air vane wheel 10 on its circumference. The narrowing gap 60 is formed between the housing 40 and an extension surface of an air vane, in particular between the housing 40 and the extension surface of the first air vane 70. A plurality of narrowing gaps between the extension surface of the air vanes and the encompassing housing 40 form the radial air bearing 110.

The narrowing gap 60 results from the extension of the extension surface 70 along the circumferential direction 80 opposite to the direction of rotation 50 owing to the fact that the extension surface of the first air vane 70, during its extension along the circumferential direction 80, approaches the encompassing housing 40. The extension surface of the first air vane 70 is extended along the circumferential direction 80 as far as the second air vane 120. The extension surface of the first air vane 70 ends above a starting point of the second air vane and above a starting point of the extension surface of the second air vane 170. The extension surface of the first air vane 70 is thus extended in the circumferential direction of the air vane wheel as far as an adjacent air vane, namely as far as the second air vane 120.

Upon a rotation of the air vane wheel 10 along the direction of rotation 50, air which is situated on the inside of the encompassing housing 40 near the edge of the encompassing housing 40 is carried along by the extension surface of the first air vane upon a rotation of the air vane wheel along the direction of rotation 50. The air is pressed together and compressed by the narrowing gap 60. The air vane wheel 10 is supported on the air cushion which forms owing to the compression of the air near the edge of the encompassing housing 40. In summary, the support provided is constituted by the air bearing 110.

In Figure 3 there is illustrated a sectional view of the air vane wheel 10 as illustrated in Figure 1. Features which are the same have been provided with the same reference symbols as in Figure 1. Figure 3 shows additionally spaces 90 and also a volume 100.

In the embodiment illustrated in Figure 3, the extension surface of the first air vane 70 is connected to the extension surface of the second air vane 170. The extension surface of the first air vane 70, the first air vane 20 and the second air vane 120 thus form a space 90. A volume 100 is thus formed between the extension surface of the first air vane 70 and the housing 40 encompassing the air vane wheel 10. In the same way, further spaces are formed between the extension surfaces of the air vanes and the air vanes of the air vane wheel 10.

Upon a rotation of the air vane wheel 10 along the circumferential direction 80, air is conveyed and/or compressed inside the spaces along the hub and/or in the radial direction by the first air vane 20, the second air vane 120 and the further air vanes. Through the connection of the extension surface of the first air vane to the second air vane 120, in particular to the radial end of the second air vane 130, a closed space 90 is created, the conveying and/or the compression of the air taking place inside the closed space 90. Upon a rotation of the air vane wheel 10 along the circumferential direction 80, air situated in the volume 100 is, moreover, compressed by the narrowing gap 60 along the circumferential direction 80 of the air vane wheel 10. Through the compression of the air situated in the volume 100, an air cushion is formed inside the volume 100, the air cushion serving to support the air vane wheel 10. The air bearing 110 is thus formed in the volume 100.

In a further embodiment, not illustrated, the air vane wheel 10 is part of a radial compressor, the air vane wheel 10 being usable as a turbine wheel and/or as a compressor wheel of the radial compressor. The housing 40 is formed as the turbine housing of the radial compressor.

Claims

Claims Air vane wheel (10) for conveying and/or for compressing air, characterised in that at least one air vane (20) of the air vane wheel (10) is shaped at a radial end (30) of the air vane (20) to form with a housing (40) encompassing the air vane wheel (10) an air bearing (110), in particular a radial air bearing and/or an axial air bearing, for supporting the air vane wheel (10).
2. Air vane wheel (10) according to Claim 1, characterised in that the at least one air vane (20) is configured to form with the housing (40) at the radial end (30) of the air vane (20) a gap (60) narrowing opposite to a direction of rotation (50) of the air vane wheel (10).
3. Air vane wheel (10) according to Claim 1 or 2, characterised in that the at least one air vane (20) is configured to form the narrowing gap (60) by an extension surface (70), the extension surface (70) extending the air vane (20) in a circumferential direction (80) of the air vane wheel (10) opposite to the direction of rotation (50) of the air vane wheel (10).
4. Air vane wheel (10) according to one of Claims ito 3, characterised in that the extension surface (70) of the air vane (20) is extended in the circumferential direction (80) of the air vane wheel (10) at least as far as an adjacent air vane (20).
5. Air vane wheel (10) according to one of the preceding claims, characterised in that the extension surface (70) of the air vane (20) is connected to the adjacent air vane (20).
6. Device having an air vane wheel (10) according to one of the preceding claims and having a housing (40) encompassing the air vane wheel (10).
7. Device according to Claim 6, characterised in that the air vane wheel (10) forms with the housing (40) an air bearing (110), in particular a radial air bearing and/or an axial air bearing, for supporting the air vane wheel (10).
8. Device according to Claim 6 or 7, characterised in that the extension surfaces (70) of the air vanes form with the housing (40) a volume (100), the volume (100) being separated from spaces (90) between the air vanes (20).
9. Device according to one of Claims 6 to 8, characterised in that the device is formed as a radial compressor, the air vane wheel (10) being formed as a turbine wheel and/or as a compressor wheel of the radial compressor.
10. Method for supporting an air vane wheel, characterised in that the air vane wheel is supported by an air bearing, the air bearing being formed on an outer circumference of the air vane wheel, which circumference is formed by air vanes of the air vane wheel.
11. Air vane wheel substantially as hereinbefore described with reference to the accompanying drawings.
12. Device having an air vane wheel, substantially as hereinbefore described with reference to the accompanying drawings.
13. Method for supporting an air vane wheel, substantially as hereinbefore described with reference to the accompanying drawings.