WO2011033800A1

WO2011033800A1 - Centrifugal compressor

Info

Publication number: WO2011033800A1
Application number: PCT/JP2010/054505
Authority: WO
Inventors: 誠一茨木; 勲冨田; 靖明陣内; 隆御子神; 正希東條; 明夫北田
Original assignee: 三菱重工業株式会社
Priority date: 2009-09-16
Filing date: 2010-03-17
Publication date: 2011-03-24
Also published as: KR20120013458A; CN102472296A; JP2011064118A; EP2441965A1; US20120148391A1

Abstract

Disclosed is a centrifugal compressor equipped with a resin housing, that is made in a manner such that compression efficiency is not lost and merits such as weight and cost reduction are not cancelled out. A turbo charger (10) is equipped with a resin housing (20) that comprises a volute section (20a) and a channel formation section (20b), and an impeller (14) that is fixed in the center of the channel formation section (20b) to a rotating shaft (12). An annular shroud (22) is disposed in a recess (20b₂) formed on the inner wall (20b₁) of the channel formation section (20b), and the annular shroud (22) forms the outer walls of a channel (c) and a diffuser (a static pressure increase region) (d) for compressed gas. The edge of the annular shroud (22) on the downstream side is fixed via a spacer (24) to a partition wall (32), which forms a portion of a bearing housing (30), by means of a bolt (26). Even if the resin housing (20) undergoes thermal deformation, the dimensions of a gap (T) between the annular shroud (22) and the curved profile (16a) of a blade (16) can be maintained at set dimensions.

Description

Centrifugal compressor

The present invention relates to a centrifugal compressor provided with a resin housing applied to, for example, a turbocharger.

A turbocharger (exhaust turbine supercharger) mounted on an automobile or the like drives a compressor by an exhaust turbine driven by the energy of exhaust gas, and supplies intake air compressed by the compressor to the engine. In this type of turbocharger, a bearing housing that rotatably supports a rotating shaft is provided between a turbine housing of an exhaust turbine and a housing of a turbo compressor. An impeller of a turbo compressor and a wheel of an exhaust turbine are fixed to a rotating shaft passing through the bearing housing.

The bearing housing houses a bearing mechanism that rotatably supports the rotating shaft. A seal wall is interposed at the boundary between the bearing housing and the compressor housing to form a compressed gas passage sealed in the compressor housing.

As a spiral housing such as a turbocharger, an aluminum cast iron or cast steel housing is usually used. Recently, however, resin-made housings have been used for the purpose of weight reduction and cost reduction.
Patent Document 1 discloses that the turbocharger housing is made of a thermoplastic resin. Patent Document 2 discloses a housing of a centrifugal compressor in which a housing wall is formed of two layers of a thermosetting resin material and a thermoplastic resin material.

Further, in Patent Document 3, an inner wall surface facing a flow path of a compressed gas in a compressor housing of a turbocharger is formed of a resin member having excellent machinability, and the curved inner surface of the compressor impeller and a curved profile portion of the compressor impeller are provided. An invention has been disclosed in which the compressor efficiency is improved by reducing the gap between the impellers and the impeller (impeller) arranged facing the inner wall surface is prevented from being damaged even if the impeller contacts the inner wall surface. Yes.

Patent Document 4 discloses that an inner wall surface of a flow path forming portion of a compressor housing of a turbocharger is made of a resin member having excellent machinability for cost reduction.
Patent Document 5 discloses that, for the same reason as Patent Document 3, the inner wall surface of the flow path forming portion of the compressor housing of the turbocharger is made of a resin member.

FIG. 10 is a schematic diagram showing a compressor portion of the turbocharger 100 having a resin housing. In FIG. 10, an impeller (impeller) 104 is fixed to the rotating shaft 102. A plurality of blades 106 project radially from the impeller 104. The outer end of the blade 106 forms a curved profile 106a. A housing 110 is disposed around the blade 106. The housing 110 includes a spiral volute portion 110a that forms the scroll portion s, and a flow path forming portion 110b that forms a flow path c of the compressed gas.

The flow path forming part 110b is disposed so as to surround the blade 106. The hub surface 108 of the impeller 104 and the inner wall of the flow path forming portion 110b form a flow path c. The flow path c is formed to be curved from the axial direction of the rotating shaft 102 (arrow a direction) to the radial direction of the impeller 104 (arrow b direction). A flow path extending from the flow path c where the blade 106 is disposed to the flow path d disposed on the outlet side of the flow path c functions as a diffuser (static pressure increasing region).

When the impeller 104 rotates, the compressed gas is sucked into the flow path c from the direction of the arrow a, and the absolute flow velocity is accelerated by the blade 106. The intake air accelerated in the flow path c changes its direction in the direction of the arrow b, enters the area of the diffuser d, decelerates the absolute flow velocity, and increases the static pressure. The compressed gas is compressed as it flows from the flow path c to the diffuser d, and flows out to the scroll portion s.

The compressor has higher compression efficiency when the gap T between the inner wall of the flow path forming portion 110b and the curved profile 106a of the impeller 104 is smaller. When the gas to be compressed is compressed by the compressor, the gas to be compressed becomes high temperature due to the compression action. When the housing 110 is made of resin, the resin has a higher coefficient of thermal expansion than that of metal, plastic, or the like. Therefore, the housing 110 is expanded by receiving the heat of the compressed gas, and as indicated by reference numeral 110 ′, the arrow e Causes thermal deformation in the direction. As a result, the gap T is enlarged, and the compressed gas leaks from the gap T, so that there is a problem that the compression efficiency is lowered.

In the case of a resin housing, if the impeller 104 is damaged and the fragments are scattered, it is necessary to prevent the fragments from jumping out of the housing. Therefore, as shown in FIG. 11, it is necessary to devise such as increasing the thickness of the housing 110 or providing reinforcing ribs 112 on the housing 110. Therefore, there is a problem that the merits of the resin housing for the purpose of weight reduction and cost reduction are offset.

German Patent Publication (DE10260042A1) European Patent Publication (EP1830071A2) JP-A-9-170442 Japanese Patent Laid-Open No. 2001-234753 JP 2002-256878 A

In view of the problems of the prior art, the present invention realizes a centrifugal compressor provided with a resin-made housing that does not reduce the compression efficiency and does not offset the advantages such as weight reduction and cost reduction. With the goal.

In order to achieve such an object, the centrifugal compressor of the present invention comprises:
A plurality of blades radially fixed to the rotating shaft, and a resin housing disposed around the impeller, the outer peripheral surface of the impeller and the inner wall of the flow path forming portion of the resin housing In the centrifugal compressor formed by forming the flow path of the compressed gas from the axial direction of the impeller toward the radial direction,
An annular shroud made of metal or ceramic material is disposed in a recess formed by engraving the inner wall of the flow path forming portion, and the outer surface of the flow path where the blade is disposed by the annular shroud and the outlet of the flow path Forming the outer surface of the diffuser (static pressure increasing region) arranged on the side,
The annular shroud is fixed to a surface or wall facing the annular shroud by the diffuser.

In the present invention, the inner wall of the flow path forming portion of the resin housing is engraved (or formed by injection molding) to form a recess, and an annular shroud made of metal or a ceramic material is disposed in the recess. This annular shroud forms the smoothly curved outer surface of the flow path and diffuser. The annular shroud is made of a material having a strength higher than that of a resin (engineering plastic stick) and a coefficient of thermal expansion smaller than that of the resin, such as a metal such as aluminum or carbon steel or ceramic. This annular shroud is fixed to the wall facing the diffuser.

The annular shroud is configured separately from the resin housing and is not joined to the inner wall of the resin housing. Therefore, since the thermal deformation of the resin housing is not transmitted to the annular shroud, the gap between the annular shroud and the curved profile of the impeller does not change. Therefore, the compression efficiency is not reduced. Further, by using the annular shroud, it is not necessary to increase the thickness of the resin housing or to provide the reinforcing rib on the resin housing, so that advantages such as weight reduction and cost reduction are not offset.

In the present invention, a seal ring may be provided in a receiving groove provided between the back surface of the annular shroud and the recess of the inner wall of the flow path forming portion in the inlet side region of the flow path. As a result, even when the resin housing is thermally deformed and a gap is generated between the inner wall of the resin housing and the annular shroud, the compressed gas enters the gap or the compressed gas on the downstream side of the impeller Does not return to the impeller inlet side. Therefore, the compression efficiency does not decrease.

Since the temperature of the compressed gas is low at the impeller inlet portion, the temperature of the inner wall of the annular shroud and the flow path forming part of the resin housing is also low. Therefore, an inexpensive seal ring such as a rubber O-ring can be used. Further, since the impeller inlet portion has a small radius, a small seal ring can be used, and the cost can be reduced accordingly.

In addition to the above configuration, the flow path forming portion of the resin housing may be divided and formed on the upstream side and the downstream side in the flow direction of the compressed gas, and the divided surface may be made to coincide with the receiving groove of the seal ring. . Thereby, the thick part of the resin housing can be eliminated. For this reason, it is possible to eliminate bubbles and the like during molding of the resin housing, thereby improving the quality of the resin housing, improving the yield, and preventing an increase in cost.
Further, since the dividing surface is made coincident with the housing groove of the seal ring, the groove processing of the housing groove becomes unnecessary, so that the molding process becomes easy and the cost can be reduced.

In the present invention, it is preferable that a slit-shaped air gap is formed in the flow path forming portion of the resin housing or the divided body of the flow path forming portion so as to open to the outside in the axial direction of the rotating shaft. Thereby, since the thick part of the resin housing can be eliminated, it is possible to eliminate residual bubbles and the like when the resin housing is molded by injection molding or the like. Therefore, the quality of the resin housing can be improved, the yield can be improved, and the cost can be prevented from increasing.

In the present invention, a compressed gas circulation space is provided between the annular shroud and the flow path forming portion, and at least two communication holes communicating the flow space and the flow path along the flow direction of the compressed gas. It is good to comprise so that the flow of to-be-compressed gas may be formed in this circulation space. Thus, when the flow rate of the compressed gas flowing through the flow path is small, a circulating flow path of the compressed gas that enters the flow space from the downstream through hole and returns to the flow path from the upstream through hole can be formed. Therefore, the flow rate at the inlet of the impeller can be maintained at a flow rate that is equal to or higher than the stall limit, so that the lower limit flow rate of the compressed gas can be reduced.

In addition, when the flow rate of the compressed gas flowing through the flow path is large, a part of the compressed gas enters the flow space from the upstream side through hole and returns to the flow path from the downstream side opening. The flow rate can be increased. As a result, the upper and lower allowable flow rates of the centrifugal compressor can be increased.

In the present invention, the outer surface of the flow path forming portion of the resin housing may be coated with an annular reinforcing layer made of glass fiber. By covering the outer surface of the flow path forming part with a reinforcing layer made of glass fiber having a high tensile strength, in the unlikely event that the blade breaks, the blade fragments or impellers do not penetrate the wall of the flow path forming part. The wall thickness of the required flow path forming part can be reduced. Therefore, the manufacturing cost of the resin housing can be reduced.

According to the centrifugal compressor of the present invention, an impeller having a plurality of blades fixed radially to a rotating shaft, and a resin housing disposed around the impeller, the outer peripheral surface of the impeller, In a centrifugal compressor in which a flow path of a compressed gas is formed from the inner wall of the flow path forming portion of the resin housing to the radial direction from the axial direction of the impeller, the inner wall of the flow path forming portion is engraved. An annular shroud made of a metal or a ceramic material is disposed in the formed recess, and an outer surface of the flow path where the impeller is disposed by the annular shroud and an outer surface of the diffuser disposed on the outlet side of the flow path are formed. By fixing the annular shroud to the partition wall facing the annular shroud with the diffuser, the gap between the annular shroud and the curved profile of the blade can be maintained at a set size. In addition to maintaining high compression efficiency, the annular shroud is disposed, so that it is not necessary to increase the thickness of the resin housing or to provide reinforcing ribs on the resin housing. And benefits such as cost reduction.

1 is a front view according to a first embodiment of a turbocharger to which the present invention is applied. It is a front view which concerns on 2nd Embodiment of the turbocharger to which this invention is applied. It is a front view which concerns on 3rd Embodiment of the turbocharger to which this invention is applied. It is a front view which concerns on 4th Embodiment of the turbocharger to which this invention is applied. It is a front view which concerns on 5th Embodiment of the turbocharger to which this invention is applied. It is a front view which shows the modification of the said 5th Embodiment. It is a front view which concerns on 6th Embodiment of the turbocharger to which this invention is applied. It is a front view which shows the modification of the said 6th Embodiment. It is a front view which concerns on 7th Embodiment of the turbocharger to which this invention is applied. It is a front view which shows a part of conventional turbocharger. It is a front view of the turbocharger shown as a comparative example which made the resin-made housing thick or attached a reinforcing rib.

Hereinafter, the present invention will be described in detail using embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this embodiment are not intended to limit the scope of the present invention to that unless otherwise specified.

Embodiment 1

A first embodiment of a turbocharger to which the present invention is applied will be described with reference to FIG. FIG. 1 shows a part of a compressor section of a turbocharger 10 according to this embodiment. In FIG. 1, a rotating shaft 12 is disposed at the center of a resin housing 20, and an impeller 14 in which a plurality of blades 16 are radially disposed in the radial direction of the rotating shaft 12 is fixedly provided on the outer peripheral surface of the rotating shaft 12. ing. The hub surface 18 of the impeller 14 is curved from the axial direction of the rotating shaft 12 toward the radial direction from the inlet side to the outlet side in the flow direction (arrow a direction) of the compressed gas. The resin housing 20 includes a spiral volute portion 20a that forms a scroll portion s therein, and a flow path forming portion 20b that forms a flow path c of a compressed gas.

The outer end of the blade 16 forms a curved profile 16a. To match the the curved profile 16a, inner wall 20b ₁ flow path forming portion 20b of the resin housing 20 are formed. A concave portion 20b ₂ for inserting and arranging the annular shroud 22 is formed in the inner wall 20b ₁ . The rotary shaft 12 is rotatably supported by a bearing (not shown) provided in the bearing housing 30. A partition wall 32 forming a part of the bearing housing 30 is arranged facing the scroll part s formed by the spiral volute part 20a. An end portion of the volute portion 20 a is attached to the partition wall 32 via a seal ring 34.

An annular shroud 22 is inserted and disposed in the recess 20b ₂ formed in the inner wall 20b ₁ of the flow path forming portion 20b. The downstream end portion of the annular shroud 22 in the flow direction of the compressed gas protrudes from the scroll portion s, and the downstream end portion is fixed to the wall 32 by the bolt 26 via the spacer 24. The annular shroud 22 is made of a metal (for example, aluminum or carbon steel) or ceramics having a strength higher than that of the resin and a coefficient of thermal expansion smaller than that of the resin. The annular shroud 22 is separated from the resin housing 20 and is not connected. The gap between the annular shroud 22 and the curved profile 16a of the blade 16 is set to be as small as possible in order to maintain good compression efficiency.

Thus, the annular shroud 22 is arranged on the flow path c for directing the compressed gas from the axial direction (arrow a direction) to the radial direction (arrow b direction) of the impeller 14 and on the outlet side of the flow path c. An outer wall of the diffuser d that converts kinetic energy into static pressure is formed. The hub surface 18 of the impeller 14 forms the inner surface of the flow path c, and the partition wall 32 forms the inner surface of the diffuser d.

With this configuration, the gas to be compressed is sucked from the inlet side of the blade 16 by the rotation of the impeller 14, and is converted into a static pressure through the flow path c and the diffuser d. The compressed gas exiting the diffuser d flows out to the scroll part s. A plurality of bolts 26 are arranged at intervals in the circumferential direction of the rotating shaft 12, and the presence of the bolts 26 does not hinder the flow of the compressed gas.

According to the present embodiment, the annular shroud 22 is fixed to the bearing housing 30 partition wall 32 with only the bolts 26, and the annular shroud 22 and the resin housing 20 are separated from each other. The thermal deformation of the housing 20 is not transmitted. Therefore, even when the resin housing 20 is thermally deformed, the gap between the annular shroud 22 and the curved profile 16a of the blade 16 does not change. Therefore, the compression efficiency is not lowered.

Further, since the annular shroud 22 is used, there is no need to increase the thickness of the resin housing 20 or to provide a reinforcing rib or the like on the resin housing 20, so that advantages such as weight reduction and cost reduction are offset. Never happen.

Embodiment 2

Next, a second embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. In FIG. 2, in the present embodiment, the downstream end 22 a of the annular shroud 22 forms two bent portions and extends until it contacts the partition wall 32 of the bearing housing 30. Flange 22a ₁ is formed on the extension end portion. On the other hand, the recess 32a for fitting the flange portion 22a ₁ is engraved in the partition wall 32. Then, the flange portion 22a ₁ are connected by bolts 40 to the recess 32a.

Incidentally, the flange portion 22a ₁ is partially formed in the circumferential direction of the impeller 14, therefore, not to close the diffuser d at the downstream side end portion 22a of the shroud 22, of the compressed gas in the diffuser d Does not obstruct the flow. Other configurations are the same as those of the first embodiment. The same parts are denoted by the same reference numerals.

According to this embodiment, annular shroud 22 forms the integral structure to the flange portion 22a _1, and is processed by press molding. Therefore, in addition to the operational effects obtained in the first embodiment, the annular shroud 22 can be easily molded, and when the annular shroud 22 is connected to the partition wall 32, the spacer 24 is used as in the first embodiment. There is an advantage that the connecting work becomes easy.

Embodiment 3

Next, a third embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. 3, in the present embodiment, in the entrance region of the flow path c, a storage groove 52 is formed in the recess 20b ₂ formed in the inner wall 20b ₁ of the flow path forming portion 20b of the resin housing 20, and the storage is performed. A rubber or resin seal ring 50 is accommodated in the groove 52. Other configurations are the same as those of the second embodiment.

According to the present embodiment, even when the resin housing 20 is thermally deformed and a gap is generated between the recess 20b ₂ and the back surface of the annular shroud 2 (made of metal or ceramic such as aluminum or carbon steel), by providing the seal ring 50, since the compressed gas from entering between the recess 20b ₂ and the annular shroud 22, the compression efficiency of the compressor is not lowered.

At the inlet portion of the impeller 14, the temperature of the compressed gas is substantially the same as that of the outside air, and the temperature of the compressed gas is low. In addition, since the temperatures of the annular shroud 22 and the flow path forming portion 20b are low at the inlet portion of the impeller 14, an inexpensive O-ring made of rubber can be used. Further, the inlet portion of the impeller 14 can use a small-diameter O-ring because the flow path of the compressed gas is not curved in the radial direction and the diameter of the impeller 14 is small. Therefore, the cost of the seal ring 50 can be reduced.
(Embodiment 4)

Next, a fourth embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. In FIG. 4, in this embodiment, the flow path forming portion 20 b of the resin housing 20 is divided into two resin divided

bodies

60 and 62. The divided

bodies

60 and 62 are divided and formed by a dividing surface 64 having a stepped portion 64a at the center of the thick portion of the flow path forming portion 20b. One end of the dividing surface 64 is connected to the accommodation groove 52 that accommodates the seal ring 34. Other configurations are the same as those of the third embodiment.

According to this embodiment, since the flow path forming portion 20b is divided and formed into the divided

bodies

60 and 62, the thickness of the flow path forming portion 20b can be reduced. This eliminates the possibility that bubbles or the like remain in the flow path forming portion 20b during the molding process of the resin housing 20. Therefore, the quality of the resin housing 20 is improved and the yield can be improved, so that the manufacturing cost of the resin housing 20 can be reduced.
Moreover, since the dividing surface 64 is connected to the receiving groove 52, the groove processing of the receiving groove 52 becomes unnecessary, and the corner portion of the divided body 60 is processed. Can be saved.
(Embodiment 5)

Next, a fifth embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. In FIG. 5, in the present embodiment, a slit-like gap is formed in the thick portion of the flow path forming portion 20 b of the resin housing 20 in a direction perpendicular to the plate thickness direction, that is, in a direction substantially parallel to the rotation direction of the impeller 14. V is provided. One end of the gap V is open to the outside. Other configurations are the same as those of the third embodiment.

According to this embodiment, by providing the gap V in the flow path forming part 20b, the thick part of the flow path forming part 20b can be eliminated. For this reason, bubbles and the like are not left during the injection molding of the resin housing 20, the quality of the resin housing 20 can be improved, and the yield can be improved, so that an increase in cost can be prevented.

Next, a modification of the fifth embodiment will be described with reference to FIG. In FIG. 6, the present modified example includes, among the divided

bodies

60 and 62 in which the resin housing 20 is divided and formed in the fourth embodiment, inside the thick portion that forms the flow path forming portion 20 b of the divided body 60. A slit-shaped gap Va is provided in a direction perpendicular to the plate thickness direction (a direction substantially parallel to the rotation direction of the impeller 14). One end of the gap Va is open to the outside. Other configurations are the same as those of the fourth embodiment.

According to the present modification, in addition to the operational effects obtained in the fourth embodiment, the slit-shaped gap Va is provided in the flow path forming portion 20b of the divided body 60. It can be lost. For this reason, bubbles and the like do not remain at the time of injection molding of the divided body 60, the quality of the divided body 60 can be improved, and the yield can be improved, thereby preventing an increase in cost.
(Embodiment 6)

Next, a sixth embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. In FIG. 7, in the present embodiment, in the flow path c, a recess 20 b 2 formed on the inner wall 20 b ₁ of the flow path forming portion 20 b is further formed so as to form a circulation flow path 70 on the back side of the annular shroud 22. is doing. An upstream through hole 72 and a downstream through hole 74 are formed in the annular shroud 22 at a position facing the circulation flow path 70. Other configurations are the same as those of the second embodiment.

According to the present embodiment, when the flow rate of the compressed gas is small, a part of the compressed gas flowing through the flow path c flows into the circulation flow path 70 from the downstream through hole 74 and flows into the circulation flow path 70. A circulating flow in which the compressed gas returns from the upstream through hole 72 to the flow path c can be formed. As a result, the circulation flow is added to the flow of the compressed gas at the inlet of the impeller 14, so that the stall of the impeller 14 can be suppressed. Therefore, the limit lower limit flow rate of the compressor can be reduced.

Further, when the flow rate of the compressed gas is large, a part of the compressed gas flowing through the flow path c flows into the circulation flow path 70 from the upstream side through-hole 72, and the compressed gas flowing into the circulation flow path 70 flows downstream. A flow path returning from the through hole 74 to the flow path c can be formed. As a result, the maximum flow rate of the compressed gas can be increased. As a result, the flow width of the compressed gas that can operate the turbocharger can be expanded.

Next, a modification of the sixth embodiment will be described with reference to FIG. In FIG. 8, the present modification is one in which a circulation channel 70 is formed on the back surface of the annular shroud 22 as in the sixth embodiment. An annular slit 76 is formed between the inlet side end of the annular shroud 22 and the inner wall 20b1 of the passage forming portion 20b at the inlet portion of the passage c. Further, a through hole 74 similar to that of the sixth embodiment is provided on the downstream side of the slit-shaped gap 76. Other configurations are the same as those of the sixth embodiment.

According to this modification, the number of through holes drilled in the annular shroud 22 can be reduced as compared with the sixth embodiment, and the recess for fitting the annular shroud 22 to the inner wall 20a of the flow path forming portion 20b. Since there is no need to engrave 20b ₂ , there is an advantage that the processing of the annular shroud 22 and the flow path forming portion 20b becomes easy. Further, since the annular slit-shaped gap 76 can be formed, the opening area of the slit-shaped gap 76 can be increased, and the slit-shaped gap 76 can be easily formed.

Embodiment 7

Next, a seventh embodiment in which the present invention is applied to a turbocharger will be described with reference to FIG. In FIG. 9, in the present embodiment, the flow passage forming portion 20b of the resin housing 20 is formed with a thin plate thickness, and an annular glass fiber plate 80 is attached to the back surface thereof. Other configurations are the same as those of the second embodiment.

In the unlikely event that the impeller 14 is damaged, it is necessary to impart strength to the flow path forming portion 20b so that the impeller 14 fragments or the damaged impeller 14 does not break through the resin housing 20. According to the present embodiment, since the glass fiber plate 80 is attached to the back surface of the flow path forming portion 20b for reinforcement, the thickness of the flow path forming portion 20b can be reduced. Further, since the thickness of the flow path forming portion 20b can be reduced, bubbles or the like do not remain at the time of injection molding of the resin housing 20, and the quality of the resin housing 20 can be improved. Therefore, the yield at the time of resin housing molding processing can be improved, and cost increase can be prevented.

According to the present invention, in a centrifugal compressor having a resin housing and applicable to a turbocharger or the like, even if thermal deformation occurs in the housing, compression efficiency is not lowered, and weight reduction and cost reduction of the housing are achieved. it can.

Claims

An impeller having a plurality of blades fixed radially to a rotating shaft, and a resin housing disposed around the impeller, and an outer peripheral surface of the impeller and an inner wall of a flow path forming portion of the resin housing In the centrifugal compressor formed by forming a flow path of the compressed gas from the axial direction of the impeller toward the radial direction,
An annular shroud made of metal or ceramic material is disposed in a recess formed by engraving the inner wall of the flow path forming portion of the resin housing, and the outer surface of the flow path where the impeller is disposed by the annular shroud and the Forming the outer surface of the diffuser arranged on the outlet side of the flow path,
A centrifugal compressor, wherein the annular shroud is fixed to a partition wall facing the annular shroud by the diffuser.
2. The centrifugal compression according to claim 1, wherein a seal ring is provided in a receiving groove provided between a back surface of the annular shroud and a recess of the inner wall of the flow path forming portion in an inlet side region of the flow path. Machine.
The flow path forming portion of the resin housing is divided into an upstream side and a downstream side in the flow direction of the compressed gas, and the divided surface is made to coincide with the receiving groove of the seal ring. 2. The centrifugal compressor according to 2.
The slit-shaped gap that opens to the outside of the flow path forming portion of the resin housing or the divided body of the flow path forming portion and that is directed in the axial direction of the rotating shaft is provided. The centrifugal compressor according to any one of the items.
A compressed gas flow space is provided between the annular shroud and the flow path forming portion, and at least two communication holes are provided to communicate the flow space and the flow path along the flow direction of the compressed gas. The centrifugal compressor according to claim 1, wherein the centrifugal compressor is provided so as to form a flow of compressed gas in the circulation space.
The centrifugal compressor according to claim 1, wherein the outer surface of the flow path forming portion of the resin housing is coated with an annular reinforcing layer made of glass fiber.