EP3224479A1

EP3224479A1 - Compressor with a sealing duct

Info

Publication number: EP3224479A1
Application number: EP15770886.8A
Authority: EP
Inventors: Alister Clay; Roger Tresch
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-11-27
Filing date: 2015-09-28
Publication date: 2017-10-04
Also published as: WO2016082979A1; KR20170089857A; DE102014224283A1; CN107002694A; US20170321713A1

Abstract

The invention relates to a compressor (1) with a housing (2) and with a rotor (3), said rotor (3) comprising a compressor wheel (5, 13) on at least one side, a compressor chamber (6, 14) being formed between the compressor wheel (5, 13) and the housing, and the rotor being rotatably mounted. An annular sealing duct (11) is formed between the rotor and the housing, said sealing duct leading from the compressor chamber to a lower pressure section. At least two throttle sections are provided in the sealing duct, in each of the two throttle sections a first section with a reduced cross-section (53, 55) of the sealing duct (11) and then a second section with an enlarged cross-section (52, 54, 56) of the sealing duct (11) being provided in the direction of flow (23) from the compressor chamber (6, 14) to the lower pressure section.

Description

description

title

The invention relates to a compressor according to claim 1.

State of the art

DE 10 2012 012 540 A1 discloses a turbocompressor in the prior art which has a first compressor stage with a first compressor wheel and a second compressor stage with a second compressor wheel. The first and the second compressor wheel are arranged on a common shaft and the shaft is mounted without contact. Between the first and the second

Compressor stage is formed a sealing gap. To seal the sealing gap, a groove is provided in the housing. In addition, the compressor wheel has a flange which engages in the groove.

DISCLOSURE OF THE INVENTION The object of the invention is to provide a compressor having an improved sealing of the sealing channel.

The object of the invention is achieved by the compressor according to claim 1.

Further embodiments of the invention are indicated in the dependent claims.

The proposed compressor has the advantage that the formation of the sealing channel between a compression chamber and a region with a lower pressure is improved. In particular, there is an axial force on the rotor reduced. In addition, the leakage is reduced via the sealing channel. Furthermore, the rotational resistance of the rotor is relatively low.

These advantages are achieved in that the sealing channel has at least two throttle sections, wherein seen in each of the two throttle sections in the flow direction from the compressor chamber to the region with the lower pressure first a first section with a reduction in the cross section of the sealing channel and then a second section an enlargement of the cross section of the sealing channel is provided. The first section accelerates the leakage current. The second section slows down and decreases the pressure of the leakage flow. By the serial arrangement of the two throttle sections, the desired sealing is achieved with a small axial force on the compressor wheel and a small loss of compressor power.

In one embodiment, the rotor and the housing each have a contour, which are formed in the form of steps. The steps are designed and arranged in such a way that the two throttle sections are realized. This embodiment has the advantage that stepped contours can be produced easily and inexpensively and can precisely realize the desired function of the two throttle sections.

In one embodiment, the contours are in the form of a rising staircase and the shape of a descending staircase, which are respectively associated with each other to represent the two throttle sections.

In a further embodiment, a first contour has the shape of a radial web and the second contour has the form of a radial recess. The web engages in the recess. Depending on the selected distances, both the radial and the axial distances between the contours can be used to form the first and the second section of the throttle sections.

In addition, depending on the selected embodiment, the recess in the radial direction can be limited by different high side walls become. In an analogous manner, the web can be defined in the axial direction of two differently high side walls.

In a further embodiment, the first portion of a throttle section is seen by a radial with respect to a rotational axis of the rotor

Constriction formed between the compressor and the housing. The second section of the throttle section is realized by an axial distance between the rotor and the housing viewed in the axial direction parallel to the axis of rotation of the rotor. In this way, the formation of the throttle sections is realized by means of a compact contour.

In a further embodiment, at least three or more throttle sections seen in the flow direction are formed successively in the sealing channel. This achieves a reduction of the leakage over the sealing gap.

Experiments have shown that the formation of the contours in the form of a recess and a web a very small leakage with low rotational resistance and a high axial force is achieved. In a further embodiment, the web, which engages in the recess, starting from the housing or from the rotor on a first portion, which merges into a second portion in the radial direction. As seen in a plane of a rotation axis of the rotor, the first portion has a smaller width than the second portion.

In a further embodiment, the second portion of the web on a radially end face arranged, annular first surface which is associated with a radially end face arranged annular second surface of the recess. The first and the second surface are in particular arranged parallel to one another. In this way, a further improvement of the seal is achieved.

Depending on the selected embodiment, the rotor has a first compressor wheel on a first side and a second compressor wheel on a second, opposite side. Using this embodiment, a low pressure stage and a high pressure stage can be realized by means of the two compressor wheels. The sealing channel between the high pressure stage and the derdruckstufe trained. Also in this embodiment, an optimization of the sealing channel is achieved by the proposed contours.

Depending on the selected embodiment, the compressor wheel can be mounted without contact in the housing, wherein the sealing channel is formed in the region of the bearing.

In a further embodiment, a sealing element is provided which represents at least one side of a throttle section or a side of a first or second section of a throttle section. The sealing element is formed of a softer material than the housing or the compressor wheel. Thus, an improved seal can be achieved.

In a further embodiment, the sealing element is formed on the housing, wherein a radial recess is formed on the sealing element, and wherein on the rotor a radial web is formed, which engages in the recess of the sealing element. This provides an improved seal.

Depending on the selected embodiment, the compressor may be designed as a turbo compressor.

The invention will be explained in more detail below with reference to FIGS. Show it

1 shows a first embodiment of a compressor with a rotor with a compressor wheel on one side,

2 shows a second embodiment of a compressor with a rotor with two compressor wheels, FIG. 3 shows an embodiment of a rotor which is mounted on a shaft,

4 shows an embodiment of a compressor, wherein a sealing element is formed on the rotor,

5 shows an embodiment of a compressor, wherein a sealing element is formed on the housing, FIGS. 6 to 10 show various embodiments of contours between the housing and the rotor,

Figures 1 1 to 14 different embodiments of contours in the form of a web and a recess for the realization of the sealing channel,

15 shows a further embodiment of a compressor,

16 shows a further embodiment of a compressor,

17 shows an additional embodiment of a compressor,

Fig. 18 is an enlarged view of the sealing channel of the embodiment of Fig. 17, and

19 shows a further embodiment of a compressor.

1 shows a schematic cross section through a part of a compressor 1 which has a housing 2 and a rotor 3. The rotor 3 is formed rotationally symmetrical to a rotation axis 4. The rotor 3 has on a first side a first compressor wheel 5 with rotor blades. Between the first

Compressor 5 and the housing 2, a first compression chamber 6 is formed. The first compression chamber 6 has in the illustrated embodiment, an annular first intake passage 7. If the rotor 3 rotates about the axis of rotation 4, a medium is sucked in via the first intake channel 7, compressed by the first compressor wheel 5 and discharged via a first compression channel 8. Between a radial outer side 9 of the rotor 3 and an associated inner side 10 of the housing 2, a sealing channel 1 1 is formed, which connects the first compression chamber 6 with a region having a lower pressure 12.

The rotor 3 may be rotatably supported by a non-contact bearing in the housing 2, for example in the region of the sealing channel 1 1. In addition, depending on the selected embodiment, the rotor 3 may be connected to a shaft, not shown, which is arranged in the axis of rotation 4 and is rotatably mounted on the housing 2. Fig. 2 shows an embodiment of a compressor 1, which is constructed according to the compressor of Fig. 1, but wherein the rotor 3 has on a second side a second compressor wheel 13 with second blades. In addition, between the second compressor wheel 13 and the housing 2, a second

Compressor chamber 14 is formed. Furthermore, the second compressor chamber

14 a second intake passage 15. In addition, a second compression channel 16 is provided in the housing 2. The second compressor wheel 13 is rotationally symmetrical to the axis of rotation 4. The second compression chamber 14 is connected via the sealing channel 1 1 with the first compression chamber 6. In addition, the second intake passage 15 with the first compression channel 8 via a line in

Connection, which is indicated schematically by an arrow. In this way, two compressor stages can be realized by means of a rotor 3 in a compressor 1. By means of the first compressor wheel 5, a pre-compression of the medium is achieved, wherein a second higher compression of the precompressed medium is achieved by the second compressor wheel 13, which is then discharged via the second compression channel 16.

Fig. 3 shows a schematic representation of an embodiment of a compressor 1 according to FIG. 2 with a rotor 3 with two compressor wheels 5, 13, which are arranged on opposite sides. The rotor 3 is rotatably mounted on the housing 2 via a shaft 19 in this embodiment. In an analogous manner, the embodiment of FIG. 1 with a rotor 3 with only a first compressor wheel 5 can be mounted on the housing 2 via a corresponding shaft 12.

Fig. 4 shows a schematic representation of the embodiment of the compressor of Fig. 2, wherein on the rotor 3 in the region of the sealing channel 1 1, an annular sealing element 17 is provided, which engages in an annular recess 18 of the housing 2. The sealing element 17 is formed, for example, from a different material than the rotor 3. In particular, a softer material can be used for the formation of the sealing element 17 in order to improve the desired sealing function. For example, the sealing element 17 may consist of a plastic material. The sealing element 17 may also be provided in a compressor 1 with a rotor 3 with only a first compressor wheel 5 according to the embodiment of FIG. FIG. 5 shows a further embodiment of the compressor of FIG. 2, wherein an annular sealing element 17 is formed on an inner side 10 of the housing 2. The sealing element 17 engages in an annular second recess 18 of the outer side 9 of the rotor 3. The compressor 1 of FIG. 1 with a rotor 3 only a first compressor wheel 5 may also have a sealing element 17 and a recess 18 according to FIG. 5.

FIGS. 6 to 10 show various stepped contours 21, 22 of the inner side 10 of the housing 2 and of the outer side 9 of the rotor 3, which are assigned to one another. Depending on the chosen embodiment, each contour

21, 22 may be realized by the rotor 3 or by the housing 2. In addition, each contour 21, 22 can be realized at least partially or completely by a sealing element 17 or have a sealing element 17 which is connected to the housing 2 or to the rotor 3.

FIG. 6 shows an enlarged, schematically represented section of the sealing channel 1 1, which is formed between a first and a second contour 21, 22. 6 shows a cross section through a plane of the rotation axis 4. Both the first and the second contour are rotationally symmetrical with respect to the axis of rotation 4 is formed. The rotation axis 4 may be arranged below the second contour 2, for example. In this embodiment, the second contour 22 is represented by the rotor 3 or a sealing element of the rotor 3. In this case, the first contour 21 is represented by the inside of the housing 2 or at least partially by a sealing element of the housing 2. Depending on the selected embodiment, the axis of rotation 4 may also be arranged above the first contour 21. Accordingly, the first contour 21 is represented by the rotor 3 or at least partially a sealing element of the rotor 3. Accordingly, the second contour 22 is represented by an inner side of the housing 2 or at least partially by a sealing element of the housing 2. These explanations also apply to the following FIGS. 7 to 10.

The first contour 21 has an annular ridge 24 in cross-section in a flow direction 23 from a region with a higher pressure in the direction of a region with a lower pressure. The region with the higher pressure can pass through the first compressor chamber 6 in the case of a rotor 3 with only a first compressor wheel 5 or through the second compressor chamber 14 in the case of a rotor 3. 3 tor with a first and a second compressor 5,13 are shown. The web 24 has the same radial height on both sides. The second contour 22 has a radial recess in the form of a groove 28. The groove 28 is in the axial direction, that is parallel to the axis of rotation 4 wider than the web 24. In addition, the web 24 projects in the radial direction in the groove 28 in.

The first contour 21, viewed in the axial direction, has in the flow direction 23 a first annular surface 31, a second annular surface 32 and a third annular surface 33. The first and third annular surfaces 31, 33 are arranged at the same radial distance from the axis of rotation 4. The second annular surface 32 limits the

Bar 24, wherein the second annular surface 32 has a greater or lesser distance from the axis of rotation 4 than the first and the third annular surface 31, 33, depending on where the axis of rotation 4 is arranged. The second contour 22 has, viewed in the axial direction in the flow direction 23, a further first, second and third annular surface 41, 42, 43. The first and second further annular surfaces 41, 42 are arranged at the same radial distance with respect to the axis of rotation 4. The second further annular surface 42 defines the groove 28, wherein the second further annular surface 42 a greater or lesser distance than the further first and further third annular surface 41, 43 in

Reference to the axis of rotation 4, depending on where the axis of rotation 4 is arranged.

The web 24 has a first axial annular surface 35 and an opposite second axial annular surface 36, wherein the first axial annular surface 35 upstream with respect to the flow direction 23 opposite the second axial annular surface 36 is arranged. The groove 28 is bounded by a first and a second axial annular surface 45, 46. The first axial annular surface 45 is arranged upstream with respect to the flow direction 23 with respect to the second axial annular surface 46.

The contours 21, 22 can be divided in the axial direction into five sections 51, 52, 53, 54, 55. The first portion 51 extends in the flow direction 23 to the further first axial annular surface 45. The second portion 52 extends in the axial direction from the axial annular surface 45 to the first axial annular surface 35. The third portion 53 extends from the first axia The fourth portion 54 extends from the second axial annular surface 36 to the further second axial annular surface 46. The fifth portion 55 extends from the further second axial annular surface 46 to the end of the first and second Contour 21, 22.

In the first, third and fifth sections 51, 53, 55, the radial distances 71, 72, 73 between the contours are decisive for influencing the flow in the sealing channel 11. In the second and fourth sections 52, 54, the axial distances 81, 82 between the side surfaces of the contours are essential for influencing the flow.

Depending on the selected embodiment, the radial distances between the contours 21, 22 in the first, third and fifth sections 51, 53, 55 and the axial distances between the contours 21, 22 in the second and fourth sections 52, 54 can be selected accordingly, to provide at least two, preferably three throttle sections. For example, the radial distances 71, 72, 73 of the first, third and fifth sections between the contours 21, 22 can be selected to be smaller than the axial distances 81, 82 between the contours 21, 22 in the second and fourth sections 52, 54 Depending on the chosen embodiment, the axial and radial distances 71, 72, 73, 81, 82 between the contours 21, 22 may be determined in various variations to realize the desired throttle sections.

Experiments have shown that a cost-effective production is achieved at least the same quality for the sealing of the sealing channel when the radial distances 71, 72,73 in the first, third and fifth sections 51, 53, 55 between the surfaces of the contours 21, 22 smaller be selected as the axial distances 81, 82 in the second and in the fourth section 52, 54 between the contours 21, 22nd

The axial and / or radial distances 71, 72, 73, 81, 82 can be in the range between 10 and 500 μm or more. In addition, the length of the sealing channel 1 1 in the range between 1 and 15 mm or more. Furthermore, the division of the sections in FIG. 6 can be selected in such a way that the web 24 fills approximately one third of the length of the sealing channel and the areas laterally of the web 24 each fill one third of the sealing channel 11. Experiments have shown that good results with a ratio of the radial distance 71, 72, 73 in the first, third and fifth sections 51, 53, 55 to an axial distance 81, 82 in the second and fourth sections 52, 54 in the range between 1: 3 or more can be achieved. For example, good results at an axial distance 81, 82 in the second and fourth sections 52, 54 of 100 to 200 μm and a radial distance 71, 72, 73 in the first, third and fifth sections 51, 53, 55 are between 10 and 30 μm reached. The axial and radial distances can be chosen differently or equally large in the sections. Experiments have shown that good results are achieved with equal radial distances and / or equal axial distances.

Fig. 7 shows a further embodiment of the sealing channel 1 1, wherein the first contour 21 seen in the flow direction 23 has a step contour with a decreasing thickness and the second contour 22 has a step contour with increasing thickness. The first and second contours 21, 22 are rotationally symmetrical to the axis of rotation 4. The first contour 21, viewed in the axial direction, has in the flow direction 23 a first annular surface 31, a second annular surface 32 and a third annular surface 33. The first radial annular surface 31 merges via a first axial annular surface 35 into the second radial annular surface 32. The second radial annular surface 32 merges via a second axial annular surface 36 into the third radial annular surface 33. In the selected embodiment, the axis of rotation 4 is arranged in the middle of the second contour 22. The annular surfaces 31, 32, 33 are aligned parallel to the axis of rotation 4. The first annular surface 31 has a smaller distance from the axis of rotation 4 than the second annular surface 32. The third annular surface 33 has a greater distance from the axis of rotation 4 than the second annular surface

32 on. If the axis of rotation 4 is arranged in the middle of the first contour 21, the radial distance between the annular surfaces and the axis of rotation 4 decreases stepwise with the flow direction 23. The second contour 22 has, viewed in the axial direction in the flow direction 23, a further first, second and third annular surface 41, 42, 43. The further first radial annular surface 41 merges via a further first axial annular surface 45 into the further second radial annular surface 42. The further second radial annular surface 42 merges via a further second axial annular surface 46 into the further third radial annular surface 43. The further first, second and third annular surfaces 41, 42,

43 each have an increasing radial distance from the axis of rotation. 4 on. If the axis of rotation 4 is arranged in the middle of the first contour 21, then the radial distance between the annular surfaces and the axis of rotation 4 decreases stepwise with the flow direction 23. In the illustrated embodiment, each overlap in the radial direction in each case the first axial annular surface 35 and the further first radial annular surface 45. Thus, an axial sealing gap with a first axial distance 81 is formed. In addition, the second axial annular surface 36 and the further second radial annular surface 46 overlap in the radial direction. Thus, a second axial sealing gap is formed with a second axial distance 82.

The contours 21, 22 can be divided in the axial direction into five sections 51, 52, 53, 54, 55. The first portion 51 extends in the flow direction 23 to the further first axial annular surface 45. The second portion 52 extends in the axial direction from the axial annular surface 45 to the first axial annular surface 35. The third portion 53 extends from the first axial annular surface The fourth section 54 extends from the second axial annular surface 36 to the further second axial annular surface 46. The fifth section 55 extends from the further second axial annular surface 46 to the end of the first and second contours

21, 22. In the first, in the third and in the fifth section 51, 53, 55, the radial distances 71, 72, 73 between the contours are decisive for influencing the flow. In the second and fourth sections 52, 54, the axial distances 81, 82 between the side surfaces of the contours are essential for influencing the flow.

Depending on the chosen embodiment, the radial distances 71, 72, 73 between the contours 21, 22 in the first, third and fifth sections 51, 53, 55 and the axial distances 81, 82 between the contours 21, 22 in the second and in the fourth Section 52, 54 are selected accordingly to provide at least two, preferably three throttle sections. For example, the radial distances 71, 72, 73 of the first, third and fifth sections between the contours 21, 22 can be selected to be smaller than the axial distances 81, 82 between the contours 21, 22 in the second and fourth sections 52, 54 Depending on the chosen embodiment, the axial and radial distances 71, 72, 73, 81, 82 between the contours 21, 22 can be varied in different directions. which variations are set to realize the desired throttle sections.

FIG. 8 shows an embodiment for a compressor 1, which substantially corresponds to FIG. 6, but with the first contour 21 formed on the rotor 3 and the second contour 22 on the housing 2. The rotation axis 4 is arranged in the middle of the second contour 22.

FIG. 9 shows a further embodiment of a compressor 1, which is mirror-symmetrical to the embodiment of FIG. 7 with respect to the flow direction 23.

FIG. 10 shows a further embodiment, which substantially corresponds to the embodiment of FIG. 5, but wherein the first and third annular surfaces 31, 33 have different radial distances from the axis of rotation 4. In an analogous manner, the further first annular surface 41 and the further third annular surface 43 also have different radial heights. In the illustrated embodiment, each overlap in the radial direction in each case the first axial annular surface 35 and the further first radial annular surface 45. Thus, an axial sealing gap with a first axial distance 81 is formed. In addition, the second axial annular surface 36 and the further second radial annular surface 46 overlap in the radial direction. Thus, a second axial sealing gap is formed with a second axial distance 82. The first axial sealing gap is longer in the radial direction than the second axial sealing gap. Depending on the selected embodiment, the second axial sealing gap may be formed longer.

FIGS. 1 to 14 show various embodiments of FIG. 5, the embodiments differing in the height of the web 24 and in the depth of the groove 28. In the figures 1 1 to 13, the radial distances 71, 72,73 between the first, second and third annular surface 31, 32, 33 and the associated further first, further second and further third annular surface 41, 42, 43 are each formed equal , The first axial annular surface 35 and the further first radial annular surface 45 overlap in the axial direction. Thus, an axial sealing gap is formed with a first axial distance 81. In addition, the second axial annular surface 36 and the further second radial annular surface 46 overlap in the radial direction. Thus, a second axial sealing gap is formed with a second axial distance 82. In FIG. 11, the axial sealing gaps 91, 92 are longer in the radial direction than in FIG. 12. The axial sealing gaps in the radial direction are longer with respect to the axis of rotation 4 than in FIG. 13, the sealing gaps in FIG 13 seen in the radial direction are longer than in Fig. 1 1.

In FIG. 14, the radial distances 71, 72, 73 between the first, second and third annular surfaces 31, 32, 33 and the associated further first, further second and further third annular surfaces 41, 42, 43 are smaller than in FIGS 1 to 13. The axial distances 81, 82 between the side walls of the groove 28 and the side walls of the web 24 may be in the range between 50 and 250 μηη, for example vary. The radial distances 71, 72, 73 may be e.g. vary in the range between 10 μηη and 100 μηη.

Depending on the embodiment selected, the first contour 21 on the housing and the second contour 22 on the rotor or the first contour 21 on the rotor and the second contour 22 on the housing can be formed in FIGS.

In addition, depending on the chosen embodiment, at least a portion of the first or second contour 21, 22, i. a portion of a contour, in particular the web 24 may be formed in the form of a sealing element 17. In addition, the entire first and / or second contour 21, 22 may be formed on a sealing element 17.

FIG. 15 shows, in a schematic partial sectional illustration, a part of a compressor 1, the housing 2 having a sealing element 17 which projects between the compressor wheels 5, 13. On a front side, the sealing element 17 has an annular peripheral groove 28 and thus the shape of the second contour 22. On the rotor 3, the first contour 21 is formed with the web 24, which projects into the groove 28 of the second contour 22. In this embodiment, further axial distances 83, 84 between the compressor wheels 5, 13 and the sealing element 17 in the range between 50 and 250 μηη example, formed. Furthermore, the radial distances 71, 72, 73 between the first and second contours 21, 22 in the region of the first, third and fifth sections 51, 53, 55 are in the range between 10 and 30 μm. In addition, the axial distances 81, 82 between the first and the second contour 21, 22 in the region of the second and the fourth portion 52, 54 formed in the range between 50 and 250 μηη.

In addition, the depth of the groove 28 seen in the radial direction in the range between see 0.5 and 3 mm or larger. The length of the bridge is corresponding

24 formed to achieve the desired second radial distance 72 in the third section 53. Depending on the selected embodiment, the first contour 21 may also be in the form of a sealing element or at least of a different material than the rotor and the compressor wheels 5, 13 thereof. For example, the first contour 21 in the form of a separate

Be manufactured component that is attached to the rotor 3.

FIG. 16 shows a further embodiment, which substantially corresponds to the embodiment of FIG. 15, but the depth of the recess on the inside of the sealing element 17 is smaller. The axial and radial distances are maintained. In particular, the depth of the recess may be in the range of 1 mm. In addition, the first contour 21 can be worked out of the material of the rotor 3, as shown in the example shown. FIG. 17 shows, in a schematic representation, a part of a compressor 1 which is constructed similarly to FIG. 15, wherein, however, the first contour 21 is formed on the housing 2 and the second contour 22 on the rotor 3. In addition, the first contour 21 has the special feature that the web 24 has a first web portion 61, which merges in the radial direction inwardly on the axis of rotation 4 in a second web portion 62. In the axial direction, the diameter of the first web portion 61 is smaller than the diameter of the second web portion 62. For example, the diameter of the first web portion 61 seen in the axial direction of the rotation axis 4 can have half the diameter of the second web portion 62. In addition, the second web portion 62 has a smaller width in the axial direction of the axis of rotation than the sealing element 17, which projects into the free space between the compressor wheels 5, 13. In addition, the sealing element 17 seen in the flow direction 23 in the fifth section 55 may have an annular recess 63, which ensures a one-sided flattening of the sealing element 17. Instead of the sealing element 17, the housing 2 may also have the first contour 21. moreover The second contour 22 can also be realized at least partially by a sealing element 17.

FIG. 18 shows a schematic representation of an enlarged representation of FIG. 17, wherein in the first section 51 a first small radial distance 71 between the first and the second contour 21, 22 is present. Subsequently, the cross section widens in the region of the second section 52, which is additionally enlarged by the thinner design of the first web section 61. Subsequently, in the third section 53, there is again a small radial second distance 72 between the contours 21, 22. Subsequently, an enlarged cross-section is again provided by the small width of the first web section 61 in the fourth section 54. In the fifth section 55, the overlap between the first and second contours relative to the first section 51 is shortened in the axial direction. This is achieved, for example, in that the sealing element 17 in this area has an annular recess 63 in the form of a draft. Thus, in a sixth section 56, a relatively large space for relaxation of the medium in the region of the drafting 63 is provided. In this embodiment, despite the small installation space more space for the relaxation of the medium after the radial sealing gaps, which are realized by the radial distances 71, 72,73 achieved.

The radial gap seals used are insensitive to axial deformations or forces. In the embodiment of FIGS. 17 and 18, a three times strong acceleration is achieved by the sections 51, 53 and 55 and a corresponding subsequent delay of the leakage medium in the sections 52, 53 and 56. The acceleration is achieved in radial sealing gaps, which are located on the smallest possible radii. The subsequent delay is achieved by increasing the flow cross-section after acceleration. The leakage medium is greatly accelerated in the first section 51, whereby a delay is achieved in the second section 52. In the third section 53, an acceleration of the

Leakage medium, which is delayed again in the fourth section 54. Accordingly, an acceleration takes place in the fifth section 55, which is delayed again in the sixth section 56. FIG. 19 shows a further embodiment of a compressor 1 which substantially corresponds to the embodiment of FIG. 17, but in contrast to FIG. 17 the compressor has only one first compressor wheel 5. The shapes shown in the figures for the surfaces that limit the sealing channel 1 1 are shown as contours formed in cross-section rectangular. The angular contours can also be formed as rounded contours. In particular, therefore, convex and / or concave contours can also be used to form the sealing channel 11. In particular, the groove 28 and / or the web 24 can have rounded edges in cross-section, so that a concave and a convex shape are opposite one another in order to form the sealing channel 11. Furthermore, in cross section, the recess 18 and / or the sealing element 17 may have rounded edges, so that a concave and a convex shape are opposite to form the sealing channel 1 1.

Likewise, the stair structures of Figures 7 and 8 may have rounded corners in cross-section. Here, too, then concave and convex surfaces are facing, which limit the sealing channel 1 1.

In addition, the surfaces of the figures, which limit the sealing channel 1 1 in the radial direction and are shown parallel to the rotation axis 4, i. the first and / or second and / or third annular surface 31, 32, 33 are also not aligned parallel to the axis of rotation 4. In particular, the first and / or second and / or third annular surface 31, 32, 33 may be aligned inclined relative to the axis of rotation 4 at different angles. Furthermore, the further first and / or further second and / or further third annular surface 41, 42, 43, which are illustrated in the figures parallel to the axis of rotation, can not be aligned parallel to the axis of rotation 4. In particular, the further first and / or further second and / or further third annular surface 41, 42, 43 may be aligned at different angles of rotation to the axis of rotation 4.

Furthermore, the surfaces of the figures, which limit the sealing channel 1 1 in the axial direction and are shown in the figures perpendicular to the axis of rotation, not perpendicular to the axis of rotation 4 may be arranged. For example, the surfaces may be aligned at different angles to the axis of rotation 4. In particular, the first and / or the second axial annular surface 35, 36 may be aligned at angles not equal to 90 ° to the axis of rotation 4. Furthermore, the further first and / or the further second axial annular surface 45,46 be aligned at angles not equal to 90 ° to the axis of rotation 4.

Claims

claims

1 . Compressor (1) with a housing (2) and with a rotor (3), wherein the rotor (3) has a compressor wheel (5, 13) on at least one side, wherein between the compressor wheel (5, 13) and the housing ( 2) one

Compressor chamber (6, 14) is formed, wherein the rotor (3) is rotatably mounted, wherein between the rotor (3) and the housing (2) an annular sealing channel (1 1) is formed, wherein the sealing channel (1 1) of of the

Compressor chamber (6, 14) is guided to a region having a lower pressure, wherein in the sealing channel (1 1) at least two throttle sections are provided, wherein in each of the two throttle sections in the flow direction

(23) from the compression chamber (6, 14) to the lower pressure region, first a first portion having a reduction (53, 55) in the cross section of the sealing channel (11) and then a second portion (52, 54, 56 ) are provided with an enlargement of the cross section of the sealing channel (1 1).

2. A compressor according to claim 1, wherein between the rotor (3) and the housing (2) in the sealing channel (1 1) two contours (21, 22) are provided, wherein the contours (21, 22) in a plane of a rotation axis ( 4) of the rotor (3), wherein the steps of the contours (21, 22) are formed in such a way that the two throttle sections (51, 52, 53, 54) are defined by the steps of the contours (21, 22). are realized.

3. A compressor according to claim 2, wherein the contours are in the form of an ascending staircase and in the form of a descending staircase.

4. The compressor of claim 2, wherein the contours in the form of at least one radial web (24) and at least one radial recess (28) are formed, and wherein the web (24) engages in the recess (28).

Compressor according to claim 4, wherein the recess (28) viewed in the axial direction of different height side walls (45,46) is limited, and wherein the web (24) seen in the radial direction of different height side walls (35, 36).

A compressor as claimed in any one of the preceding claims, wherein the first portion (51, 53, 55) of the throttle portion is defined by a radial throat (71, 72, 73) between the rotor (3) and the housing (2), as viewed in relation to an axis of rotation of the rotor ), and wherein the second portion (52, 54) of the throttle portion by an axially parallel to the axis of rotation of the rotor (3) seen axial distance (81, 82) realized between the rotor (3) and the housing (2) is.

Compressor according to one of the preceding claims, wherein at least three or more throttle sections (51, 52, 53, 54, 55, 56) seen in the flow direction (23) in the sealing channel (1 1) are provided.

Compressor according to one of the preceding claims, wherein the web (24) starting from the housing (2) or from the rotor (3) has a first portion (61) which merges into a second portion (62), wherein in one plane a rotation axis (4) of the rotor (3) seen the first portion (61) has a smaller width than the second portion (62).

A compressor according to claim 8, wherein the second portion (62) has an annular first surface arranged radially on the front side, which is associated with a radially end-side annular second surface of a recess in the form of a radial groove (28), wherein in particular the first and second surfaces parallel to each other are arranged.

10. Compressor according to one of the preceding claims, wherein the

Compressor (5) on a first side of the rotor (3) is formed, wherein on a second side opposite the first side of the rotor (3), a further compressor wheel (13) is formed, wherein the further

Compressor (13) a high pressure stage and the compressor wheel (5) represent a Niederdruckdruckstufe, wherein the further compressor wheel (13) in a further compression chamber (14) of the housing (2) is arranged, wherein between the compression chamber (6) and the further compression chamber (14) of the sealing channel (1 1) is formed.

1 1. Compressor according to one of the preceding claims, wherein the rotor (3) via a non-contact bearing is rotatably mounted on the housing (2), and wherein the sealing channel (1 1) is formed in the region of the bearing.

12. A compressor according to any one of the preceding claims, wherein on the rotor (3) and / or on the housing (2) a sealing element (17) is formed, wherein the sealing element (17) made of a softer material than the rotor (3) or Housing (2) is formed, wherein the sealing element (17) is at least one side of at least one throttle section.

13. A compressor according to claim 12, wherein the sealing element (17) is formed on the housing (2), wherein in the sealing element a radial recess (28) is formed, wherein on the rotor (3) a radial web (24) is formed, in the recess (28) engages.

14. Compressor according to one of the preceding claims, wherein the compressor is designed as a turbocompressor.