JP5808036B2 - Centrifugal compressor - Google Patents

Description

  The present invention particularly has a casing comprising an inflow channel and a spiral channel, and a compressor impeller is axially mounted in the casing, and the casings are respectively The centrifugal compressor for turbochargers described in (2) is a turbocharger centrifugal compressor composed of at least two casing parts between which at least one cavity is formed.

  Turbomachines, when incorporated into internal combustion engines and used as turbochargers, are generally used to compress inhaled fresh air to a high pressure level in order to increase performance and efficiency. On the exhaust side of the turbocharger, the casing is made of metal due to high temperature and high pressure. Furthermore, a mechanical turbocharger in which the compressor-side casing is made of plastic, or a turbomachine in which the compressor is electrically driven are also known. When the compressor is driven, a considerable amount of noise is generated particularly in a high rotation speed (frequency) region, and since these are high-frequency noises, they feel uncomfortable and annoying. This is a constant sound caused by the naturally dynamic frequency of the rotating shaft and oil film. In addition, there are countless noises that fluctuate in their frequency spectrum caused by, for example, shaft imbalance, pulsation, and aerodynamic effects (eg, compressor or turbine blade circulation). The frequency range of the noise in question is usually in a very large bandwidth from about 1,000 Hz to 20,000 Hz. These noises are now introduced into the structure as individual propagating noise and radiated therefrom. Part of the further background noise is emitted directly as airborne sound. The air transmission sound propagates on the air transmission sound path.

  In order to attenuate the sound emitted from the inside of the turbocharger, Patent Document 1 has already proposed a centrifugal compressor in which a casing and a pressure port are made of plastic. Noise attenuation is provided with an acoustically effective opening in the area of the spiral casing, which is formed as a flat bottom hole or a chamber separated from the flow path by a perforated plate.

  Patent Document 2 discloses a casing for a centrifugal compressor composed of three casing parts connected to each other on an adhesive surface.

German Patent No. 10112764A1 German Patent No. 202007016282U1

  The object of the present invention is to provide a centrifugal compressor for a turbocharger in which a clear noise reduction is achieved in a simple manner in its casing.

  This problem is characterized by the features of claim 1 (the inflow path (19) by which the cavity (18; 31, 32; 33) is connected in communication with the inflow channel (19)). This is solved by a centrifugal compressor with openings (15, 28, 29).

  In particular, the present invention is based on the knowledge that sound waves propagating in the direction of the air suction outlet adversely affect the outlet noise in addition to the radiation noise of the air guiding section. This phenomenon is eliminated by the provision of at least one cavity connected to the inflow channel through at least one opening. Therefore, by providing the opening in the suction cross section of the compressor, sound attenuation can be directly performed by the sound source.

  According to a preferred development of the invention, the inflow channel is formed substantially by the axial part of the central casing part. Alternatively, the inflow channel can be formed substantially by the axial part of the upper part of the casing and the axial part of the central casing part.

  There are many possibilities to form an opening that connects the inflow channel in communication with the cavity. One possibility of forming this is obtained by the opening in the inflow channel being formed by the space between the upper part of the casing and the axial part of the central casing part. Slots extending in the circumferential direction between the axial portions are added to this space.

  An alternative configuration is that a large number of openings are provided in the axial part. These openings can be formed, for example, as elliptical holes that preferably extend parallel to each other in the axial direction of the inflow channel. In addition, it is also possible to configure the opening in a circular or polygonal shape. A particularly preferred configuration of the invention is that a partition wall is provided, thereby forming two or more cavities (comparted by the partition wall). In this way, individual gaps are provided (by two or more cavities), where these individual gaps can be different in size or the same size. The structure of the casing by a plurality of parts is effective in that the cavity is formed in an annular shape or surrounds the axial part.

  As the partition wall, for example, an annular radial partition wall that separates an upper cavity and a lower cavity having individual gaps from each other can be provided. Alternatively, an axial partition wall can be provided, but here two or more partition walls form a corresponding number of cavities. In this case, preferably three axial partitions are provided which surround the axial part and thereby form three ring segment cavities.

  The casing part is preferably made of a thermoplastic, such as PPS (polyphenyl sulfide). The casing parts are connected to one another by, for example, friction welding.

  According to the invention (as an effect), a clear noise reduction is achieved in a simple manner in the casing of the centrifugal compressor.

It is a figure which shows the cross section of the axial direction of the casing of a centrifugal compressor. It is a figure which shows the alternative structure of the casing by FIG. FIG. 7 shows a further alternative embodiment of the casing according to FIG. 1. FIG. 3 is a view of FIG. 2 with an annular radial partition wall forming two cavities. FIG. 4 is a view of FIG. 3 having an axial partition wall forming a number of cavities. It is the schematic which shows the cavity formed of the partition wall in FIG.

  FIG. 1 shows a casing 1 formed of three casing parts, in which a central part 4 is arranged between an upper part 2 and a lower part 3. These casing parts 2, 3, 4 are made of a thermoplastic, preferably PPS (polyphenyl sulfide). Two annular joining surfaces 5, 6 are formed on the upper part 2, where the joining surface 5 has a contact surface 7 of the lower part 3, and the joining surface 6 has a contact surface 8 of the central part 4. . The joining surface 5 and the contact surface 7 as well as the joining surface 6 and the contact surface 8 each form a weld zone, to which the parts are firmly joined.

  The upper portion 2 is formed with a curved portion 9 opened downward, which extends in a ring shape and expands in the circumferential direction. A joint surface 6 is formed at a radially inner end of the curved portion 9, and a circular portion 10 adapted to the shape of the curved portion 9 formed in the central portion 4 is connected to the contact surface 8. doing. Furthermore, the central part 4 comprises an axial part 11 having a circular shape 12 with respect to the radial part 13 in which the circular part 10 is formed.

  An axial portion 14 is formed on the upper portion 2 in the same row as the axial portion 11 of the central portion 4. The axial portions 11 and 14 form an inflow channel 19, where a space exists between the portions 11 and 14, and a slot 15 extending in the circumferential direction is formed by the space. The axial part 14 of the upper part 2 is connected to the bending part 9 via wall parts 16 and 17. These walls 16, 17 and axial portions 11, 14, circular 12 and radial portion 13 define an annular cavity 18 extending around the axial portions 11, 14, which defines the slot 15. And an inflow channel 19 formed by the axial portions 11 and 14 so as to communicate with each other.

  The lower portion 3 is substantially formed as an annular curved portion 20 that extends in the circumferential direction, and an axial sleeve 21 that extends upward is connected to the outer side in the radial direction, and a contact surface at the upper end thereof. There are seven. Since the axial portion 22 of the upper part 2 is close to the inner wall of the sleeve 21, the casing 1 is a double wall in this region. The lower part 3 is formed on the lower side to receive a casing bottom part (not shown). Here, the lower part 3 is provided with a protrusion 23 directed radially inward. As is apparent from the drawing, the curved portion 9 forms a spiral flow path 24 in the upper portion 2, the circular portion 10 in the central portion 4, and the curved portion 20 in the lower portion 3.

  FIG. 2 shows the casing 1 in an alternative configuration, in which the central part 4 is provided with a longer axial part 27 that reaches the lower end of the radially extending wall part 16. A further joining surface 25 is provided at the lower end of the wall 16, against which a contact surface 26 of the part 27 abuts, on which the upper part 2 and the central part 4 are also in the faces 6, 8. Just as tightly coupled. The cylindrically formed portion 27 is provided with a number of elliptical holes 28, which are formed as slots extending in parallel in the illustrated example. It is connected so that it can communicate. In other respects, the reference numerals for the same parts are the same as those in FIG. 1, so that the description of FIG. 1 can be referred to.

  FIG. 3 shows a further embodiment of the casing 1, in which circular openings 29 are arranged in a cylindrically shaped axial part 27, by means of which (by this) the cavity 18. Is connected to the inflow channel 19 so as to be communicable with the embodiment (thing) of FIG. Of course, other shapes of openings are possible, for example irregular polygons or regular polygons. The other reference numerals correspond to those in FIG.

  FIG. 4 shows a drawing similar to FIG. 4 differs from FIG. 2 in that an annular radial partition wall 30 is provided in the cavity surrounding the radial portion 27, so that in the drawing of the casing 1, an upper cavity 31 and a lower cavity 32 are shown. Is formed. Each of the cavities 31 and 32 is connected to the inflow channel 19 through an oval hole 28 so as to be able to communicate therewith. All other reference numerals correspond to those in FIG. 2 for the same parts.

  FIG. 5 shows the implementation option of FIG. 3, wherein at least two axial partition walls 34 are arranged in the cavity surrounding the axial portion 27, of which only the partition wall 34 is shown in FIG. appear. These partition walls 34 serve to form a number of cavities 33, as is apparent from the schematic view of FIG. In other respects, the reference numerals in FIG. 5 are the same as those in FIG. 3 for the same parts.

  By dividing the multiple cavities 31, 32 in FIG. 4 or 33 in FIGS. 5 and 6, a gap corsing, and thus two or more individual gaps are formed. These individual gaps can be different sizes or the same size.

DESCRIPTION OF SYMBOLS 1 Casing 2 Casing component 3 Casing component 4 Casing component 5 Joining surface 6 Joining surface 7 Contact surface 8 Contact surface 9 Curved part 10 Circular part 11 Axial part 12 Circular part 13 Radial part 14 Axial part 15 Opening (slot)
DESCRIPTION OF SYMBOLS 16 Wall part 17 Wall part 18 Cavity 19 Inflow flow path 20 Curved part 21 Sleeve 22 Axial part 23 Protrusion part 24 Spiral (spiral) flow path 25 Joining surface 26 Contact surface 27 Axial part 28 Opening (elliptical hole)
29 Opening 30 Partition wall 31 Cavity 32 Cavity 33 Cavity 34 Partition wall

Claims (13)

A casing (1) comprising an inflow channel (19) and a spiral channel (24);
A compressor impeller disposed in the casing (1), and a centrifugal compressor comprising:
The casing (1)
A casing central part (4) having a cylindrical axial part (11, 27) forming at least part of said inflow channel (19) and a radial part (13) extending radially outward; ,
A casing upper part (2) forming at least one cavity (18; 31, 32; 33) with said casing central part (4);
The casing central part (4) and the casing upper part (2) are made of thermoplastics,
The axial portion (11, 14) is formed with at least one opening (15, 28, 29) communicating the inflow channel (19) and the cavity (18; 31, 32; 33). And
The cavity (18; 31, 32; 33) is formed with a partition wall (30, 34) for partitioning the cavity (18; 31, 32; 33) into two or more cavities. Centrifugal compressor.   The centrifugal compressor according to claim 1, characterized in that the inflow channel (19) is substantially formed by an axial part (27) of the casing central part (4). The inflow channel (19) is substantially formed by an axial part (14) of the casing upper part (2) and an axial part (11) of the casing central part (4);
The centrifugal compressor according to claim 1, characterized in that the opening in the inflow channel (19) is formed by a space between the axial part (14) and the axial part (11).   The centrifugal compressor according to claim 3, wherein the opening in the inflow channel (19) is formed as a slot (15) extending in the circumferential direction.   3. Centrifugal compressor according to claim 2, characterized in that a number of openings (28, 29) are provided in the axial part (27).   6. Centrifugal compressor according to claim 5, characterized in that the opening is formed as an elliptical hole (28).   The centrifugal compressor according to claim 6, wherein the elliptical holes (28) extend in parallel to each other in the axial direction of the inflow channel (19).   The centrifugal compressor according to claim 7, wherein the opening (29) is circular or polygonal.   The centrifugal compressor according to any one of claims 1 to 8, wherein the cavity (18; 31, 32) is formed in an annular shape. The centrifugal compressor according to any one of claims 1 to 8, wherein the cavity (33) is formed so as to surround the axial portion (11, 14; 27).   The centrifugal compressor according to claim 9, wherein the partition wall is composed of an annular partition wall (30) that partitions the cavity into an upper cavity (31) and a lower cavity (32).   The centrifugal compressor according to claim 9, wherein the partition wall is composed of at least two axial partition walls (34) that partition the annular cavity into three or more cavities (33). 13. The axial partition wall (34) of the three forms a ring segment-shaped cavity (33) surrounding the axial portion (11, 14; 27). Centrifugal compressor.

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