Compressor for turbocharger

Abstract

To provide a compressor for a turbocharger capable of making it unlikely for noise, vibrations and the like by a resonance phenomenon to occur when a compressor impeller rotates.SOLUTION: In a compressor housing 3 of a compressor 1 for turbocharger, a shroud flow path 32 rotatably housing a compressor impeller 2 and a circulation flow path 33 where a part of air A flowing in the shroud flow path 32 is circulated to an upstream side L1 of the shroud flow path 32 on an outer peripheral side of the shroud flow path 32 are formed. At an exit communication part 333 of the circulation flow path 33 connected to the shroud flow path 32, a plurality of guide vanes 41 for guiding the air A flowing in the circulation flow path 33 to the upstream side 210 of an impeller vane 21 is arranged in a circumferential direction C and formed. At least any of formation pitches in the circumferential direction C between the plurality of guide vanes 41 differs from other formation pitches.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a compressor for a turbocharger.

Background Art

[0002] A turbocharger mounted on an internal combustion engine of an automobile or the like includes a turbine that rotates by receiving a flow of exhaust gas from the internal combustion engine, and a compressor that is arranged on the same shaft as the turbine and compresses air by receiving the rotational force of the turbine. In the compressor, a compressor impeller is rotatably accommodated in a compressor housing. In the compressor, for purposes such as suppressing surging and improving compression efficiency, air introduced into the compressor impeller is circulated and the like.

[0003] For example, in the housing of a centrifugal compressor for a turbocharger disclosed in Patent Document 1, a guide vane provided in an annular air chamber in a shroud portion, and a circulation flow passage that guides compressed air introduced from the air chamber to the upstream portion of the impeller are formed. Thereby, the air compressed by the impeller is efficiently circulated to the upstream side of the impeller, and surging of the centrifugal compressor is suppressed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In compressors for turbochargers, guide vanes and circulation channels are formed to solve the problem of surging, where the discharge pressure of compressed air decreases due to the rotation of the impeller, causing unstable operation. However, the inventor's research has shown that when guide vanes are formed, if the positions of the guide vanes and the impeller vanes of the compressor impeller coincide simultaneously at multiple points in the circumferential direction as the compressor impeller rotates, noise, vibration, etc., due to resonance phenomena are likely to occur. Furthermore, in addition to the guide vanes, if there are protrusions or other objects that coincide simultaneously with the impeller vanes at multiple points in the circumferential direction when the compressor impeller rotates, it is thought that noise, vibration, etc., may occur due to resonance phenomena.

[0006] This invention has been made in view of the above problems, and aims to provide a compressor for a turbocharger that can reduce noise, vibration, etc. caused by resonance when the compressor impeller rotates. [Means for solving the problem]

[0007] One aspect of the present invention is, A compressor impeller having multiple impeller vanes arranged in the circumferential direction, The compressor housing comprises a shroud passage in which the compressor impeller is housed in a rotatable state, and a circulation passage formed on the outer circumference of the shroud passage, which allows a portion of the air flowing through the shroud passage to be recirculated to the upstream side of the shroud passage. At the outlet of the circulation channel connected to the shroud channel, a plurality of guide vanes are formed in a circumferential direction to introduce the air flowing through the circulation channel to the upstream part of the impeller vane. At least one of the circumferential formation pitches between the plurality of guide vanes is different from the other formation pitches. the law of nature, Multiple impeller vanes are formed and arranged at equal intervals in the circumferential direction. The guide vane is formed at an upstream position in the axial direction of the circulation channel, projecting radially from the outer circumference to the inner circumference and axially from the upstream to the downstream side. The relationship between the number of guide vanes and the number of impeller vanes is such that there is a common divisor other than 1. When the compressor impeller rotates, at least one of the circumferential forming pitches between the multiple guide vanes is different from the other forming pitches so that the circumferential center position on the inner end face of the guide vane and the circumferential width range on the upstream end face of the impeller vane do not overlap at multiple locations in the circumferential direction simultaneously. It is located in the compressor for the turbocharger.

[0008] As a reference example, A compressor impeller having multiple impeller vanes arranged in the circumferential direction, The compressor housing comprises a shroud passage in which the compressor impeller is housed in a rotatable state, and a circulation passage formed on the outer circumference of the shroud passage, which allows a portion of the air flowing through the shroud passage to be recirculated to the upstream side of the shroud passage. Multiple flow path partitions are formed in a circumferential direction, dividing the aforementioned circulation flow path. At least one of the circumferential forming pitches between the multiple flow path partitions is different from the other forming pitches, for a turbocharger compressor. but be.

[0009] Other reference examples include, A compressor impeller having multiple impeller vanes arranged in the circumferential direction, The compressor housing comprises a compressor housing in which a shroud passage is formed, in which the compressor impeller is housed in a rotatable state, The compressor housing has a plurality of flow straightening fins arranged circumferentially at the intake port on the upstream side of the shroud passage, At least one of the circumferential formation pitches between the plurality of rectifier fins is different from the other formation pitches, for a turbocharger compressor. but be. [Effects of the Invention]

[0010] In the compressor for a turbocharger according to the above embodiment, the formation pitch of at least one of the multiple guide vanes is made non-uniform. Specifically, at least one of the formation pitches in the circumferential direction between the multiple guide vanes is made different from the other formation pitches. This configuration makes it possible to prevent the formation positions of the guide vanes and the formation positions of the impeller vanes of the compressor impeller from coinciding simultaneously at multiple locations in the circumferential direction when the compressor impeller rotates.

[0011] Therefore, according to the compressor for a turbocharger of the above-described embodiment, noise, vibration, etc., due to resonance phenomena can be less likely to occur when the compressor impeller rotates.

[0012] In another embodiment of the present invention, a compressor for a turbocharger has non-uniform formation pitches for at least one of the multiple flow path partitions. Specifically, at least one of the circumferential formation pitches between the multiple flow path partitions is made different from the other formation pitches. This configuration makes it possible to prevent the formation positions of the flow path partitions and the formation positions of the impeller vanes of the compressor impeller from coinciding simultaneously at multiple locations in the circumferential direction when the compressor impeller rotates.

[0013] Therefore, according to the compressor for turbocharger of the above embodiment, noise, vibration, etc. due to resonance phenomena can be less likely to occur when the compressor impeller rotates.

[0014] In yet another embodiment of the present invention, in a compressor for a turbocharger, the formation pitch of at least one of the multiple rectifier fins is made non-uniform. Specifically, at least one of the circumferential formation pitches between the multiple rectifier fins is made different from the other formation pitches. This configuration makes it possible to prevent the formation positions of the rectifier fins and the formation positions of the impeller vanes of the compressor impeller from coinciding simultaneously at multiple locations in the circumferential direction when the compressor impeller rotates.

[0015] Therefore, according to the compressor for a turbocharger of the above aspect, it is possible to make noise, vibration, etc. caused by resonance phenomenon less likely to occur when the compressor impeller rotates. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [Figure 1] An explanatory view showing the compressor for a turbocharger according to Embodiment 1 in cross section. [Figure 2] An explanatory view showing an enlarged part of Fig. 1 according to Embodiment 1. [Figure 3] An explanatory view showing the compressor impeller according to Embodiment 1 in a perspective state. [Figure 4] An explanatory view showing the periphery of the guide vane of the compressor housing according to Embodiment 1 in a perspective state. [Figure 5] An explanatory view showing the periphery of the circulation flow path of the compressor housing according to Embodiment 1 in a perspective state. [Figure 6] A VI-VI cross-sectional view of Fig. 1 showing a plurality of guide vanes formed at non-uniform formation pitches in the circumferential direction according to Embodiment 1. [Figure 7] A view corresponding to the VI-VI cross-section of Fig. 1 showing another plurality of guide vanes formed at non-uniform formation pitches in the circumferential direction according to Embodiment 1. [Figure 8] A view corresponding to the VI-VI cross-section of Fig. 1 showing a plurality of guide vanes formed at uniform formation pitches in the circumferential direction according to Comparative Embodiment 1. [Figure 9] An explanatory view showing the compressor for a turbocharger according to Embodiment 2 in cross section. [Figure 10] An explanatory view showing an enlarged part of Fig. 9 according to Embodiment 2. [Figure 11] A perspective cross-sectional view of a part of the circulation flow path according to Embodiment 2. [Figure 12] A XII-XII cross-sectional view of Fig. 10 showing a plurality of flow path partition portions formed at non-uniform formation pitches in the circumferential direction according to Embodiment 2. [Figure 13]This is a cross-sectional view corresponding to section XII-XII in Figure 10, showing multiple flow channel partitions formed with a uniform formation pitch in the circumferential direction, relating to comparative form 2. [Figure 14] An explanatory diagram showing a cross-sectional view of a compressor for a turbocharger according to Embodiment 3. [Figure 15] A view taken along arrow XV in Figure 14, showing a plurality of rectifying fins formed with a non-uniform formation pitch in the circumferential direction, according to Embodiment 3. [Figure 16] This figure, corresponding to the view taken by arrow XV in Figure 14, shows multiple flow channel partitions formed with a uniform formation pitch in the circumferential direction, relating to comparative form 3. [Modes for carrying out the invention]

[0017] A preferred embodiment of the compressor for the turbocharger described above will be explained with reference to the drawings. <Embodiment 1> The compressor 1 for the turbocharger in this embodiment comprises a compressor impeller 2 and a compressor housing 3, as shown in Figures 1 to 3. Multiple impeller vanes 21 are formed on the compressor impeller 2, arranged in the circumferential direction C. The compressor housing 3 has a shroud passage 32 in which the compressor impeller 2 is housed in a rotatable state, and a circulation passage 33 formed on the outer circumference side of the shroud passage 32, through which a portion of the air A flowing through the shroud passage 32 is recirculated to the upstream side L1 of the shroud passage 32.

[0018] As shown in Figures 4 to 6, the outlet communication section 333, which serves as the outlet of the circulation channel 33 connected to the shroud channel 32, has multiple guide vanes 41 formed in a circumferential direction C to introduce the air A flowing through the circulation channel 33 to the upstream section 210 of the impeller vane 21. At least one of the formation pitches θ in the circumferential direction C between the multiple guide vanes 41 is different from the other formation pitches θ.

[0019] The compressor 1 for this turbocharger configuration will be described in detail below. As shown in Figure 1, a turbocharger is mounted on an internal combustion engine, such as an engine used in an automobile. The turbocharger comprises a turbine that rotates in response to the flow of exhaust gas from the internal combustion engine, and a compressor 1 that is arranged on the same axis as the turbine and compresses air A in response to the rotational force of the turbine. The turbine wheel and the compressor impeller (compressor wheel) 2 are located on both sides of the rotating shaft 11 and are housed within a housing. The compressor housing 3 constitutes part of the housing.

[0020] (Compressor propeller 2) As shown in Figures 2 and 3, the compressor impeller 2 has a rotating base 20 whose outer diameter increases from the upstream side L1 to the downstream side L2 in the axial direction L, and a plurality of impeller vanes 21 formed on the outer surface of the rotating base 20, whose outer diameter increases from the upstream side L1 to the downstream side L2 in the axial direction L, in order to discharge air A drawn in from the upstream side L1 in the axial direction L to the outer circumference side in the radial direction R at the downstream side L2 in the axial direction L. The rotating base 20 is positioned on the outer circumference of the rotating shaft 11. The plurality of impeller vanes 21 are formed at equal intervals in the circumferential direction C. Each impeller vane 21 is formed in a state inclined from one side to the other in the circumferential direction C as it moves from the upstream side L1 to the downstream side L2 in the axial direction L. In other words, each impeller vane 21 is formed in a state in which it is spirally twisted in the circumferential direction C.

[0021] The upstream end face 211 and the downstream end face of each impeller vane 21 are arranged along the radial direction R. In this embodiment of the compressor impeller 2, auxiliary impeller vanes 22 are arranged between adjacent impeller vanes 21 in the circumferential direction C. The upstream end face 221 of each auxiliary impeller vane 22 is positioned downstream L2 in the axial direction L from the upstream end face 211 of each impeller vane 21. Note that auxiliary impeller vanes 22 are not required to be formed on the compressor impeller 2.

[0022] (Compressor housing 3) As shown in Figures 1 and 2, the compressor housing 3 is formed by combining multiple parts to house the compressor impeller 2 inside. In this embodiment, an example of the multiple parts constituting the compressor housing 3 is shown. The compressor housing 3 in this embodiment has a first housing 3A located on the upstream side L1 of the air A flow in the compressor 1, a second housing 3B located on the downstream side L2 of the first housing 3A, and a third housing 3C and a fourth housing 3D located on the downstream side L2 of the second housing 3B. The upstream side L1 of the air A flow refers to the upstream side L1 in the axial direction L.

[0023] The compressor housing 3 has an intake port 31, a shroud passage 32, a circulation passage 33, a diffuser passage 34, and a scroll chamber 35. The intake port 31 is formed on the upstream side L1 of the axial direction L of the compressor housing 3 and is the part into which air A flows toward the compressor impeller 2. The shroud passage 32 is formed on the downstream side L2 of the axial direction L of the intake port 31 and is the part into which air A is drawn in by the compressor impeller 2 toward the downstream side L2 of the axial direction L and toward the outer circumference C. The circulation passage 33 is formed on the outer circumference of the shroud passage 32 in the radial direction R and is the part into which a portion of the air A flowing toward the downstream side L2 of the shroud passage 32 toward the upstream side L1 of the axial direction L of the shroud passage 32 is circulated.

[0024] The diffuser passage 34 is formed downstream L2 in the axial direction L of the shroud passage 32, extending from the inner circumference to the outer circumference in the radial direction R, and is the portion where the air A discharged from the compressor impeller 2 to the outer circumference in the radial direction R is pressurized. The scroll chamber 35 is formed on the outer circumference in the radial direction R of the diffuser passage 34, and is the portion where the air A compressed by the diffuser passage 34 is guided to the outside of the compressor housing 3.

[0025] As shown in Figure 2, the first housing 3A has an intake port 31, a shroud passage 32, a circulation passage 33, and a guide vane 41 at the inner circumference in the radial direction R, and the upstream L1 portion of the diffuser passage 34 and the upstream L1 portion of the scroll chamber 35 in the axial direction L are formed at the intermediate and outer circumference in the radial direction R. The second housing 3B has the downstream L2 portion of the scroll chamber 35 in the axial direction L at the outer circumference in the radial direction R.

[0026] The third housing 3C and the fourth housing 3D are equipped with bearings (not shown) that support the rotating shaft 11. The third housing 3C also forms the downstream portion L2 in the axial direction L of the diffuser flow path 34.

[0027] The circulation channel 33 and guide vanes 41 are formed to increase the flow rate of air A flowing through the shroud channel 32 by recirculating a portion of the air A flowing through the shroud channel 32, thereby suppressing surging caused by insufficient air A flow. The circulation channel 33 is formed by an annular channel section 331, an inlet communication section 332, and an outlet communication section 333.

[0028] As shown in Figures 2 and 5, the annular channel section 331 is formed in an annular shape on the outer circumference of the shroud channel section 32 in the radial direction R, extending in the axial direction L. The inlet communication section 332 connects the shroud channel section 32 and the position L2 downstream of the annular channel section 331 in the axial direction L, in the radial direction R at multiple locations in the circumferential direction C. The outlet communication section 333 connects the shroud channel section 32 and the position L1 upstream of the annular channel section 331 in the axial direction L, in the radial direction R at multiple locations in the circumferential direction C separated by multiple guide vanes 41.

[0029] The inlet communication section 332 is formed between columnar connecting sections 334 provided at multiple locations in the circumferential direction C on the protruding section 30 that separates the shroud flow path 32 and the circulation flow path 33. The protruding section 30 is formed in the first housing 3A, projecting from the downstream side L2 to the upstream side L1 in the axial direction L. The outlet communication section 333 in this embodiment is formed as a space 42 formed between the guide vanes 41 in the circumferential direction C.

[0030] As shown in Figures 4 and 6, the guide vanes 41 are formed at a position L1 on the upstream side in the axial direction L of the annular flow channel 331 of the circulation channel 33, projecting from the outer circumference to the inner circumference in the radial direction R, and also projecting from the upstream side L1 to the downstream side L2 in the axial direction L. The multiple guide vanes 41 are formed inclined with respect to the radial direction R from one side to the other in the circumferential direction C. The rotation direction S of the compressor impeller 2 is the same as the direction in which the multiple guide vanes 41 are inclined from the outer circumference to the inner circumference in the radial direction R. However, the shape of the guide vanes 41 is not particularly limited, and for example, the multiple guide vanes 41 can be shaped along the radial direction R.

[0031] As shown in Figures 2 and 6, each guide vane 41 is located on the outer circumference side in the radial direction R relative to the upstream portion 210 of each impeller vane 21. Furthermore, on each impeller vane 21, the upstream end face 211 is located closest to the inner end face 411 of each guide vane 41. The generation of noise, vibration, etc., when the compressor impeller 2 rotates is greatly influenced by whether the position C in the circumferential direction of the inner end face 411 of each guide vane 41 and the position C in the circumferential direction of the upstream end face 211 of each impeller vane 21 coincide (or overlap) at multiple locations simultaneously.

[0032] In this embodiment, the width Wg of the circumferential C at the inner end face 411 of each guide vane 41 is greater than the width Wi of the circumferential C at the upstream end face 211 of each impeller vane 21. In this embodiment, the upstream end face 211 of each impeller vane 21 is formed along the radial direction R. In contrast to this embodiment, the upstream end face 211 of each impeller vane 21 is formed curved with respect to the radial direction R. It is It can also be expressed as a form. In this case, "Wi of the circumferential direction C at the upstream end face 211 of the impeller vane 21" is the width Wi of the circumferential direction C at the outermost position of the radial R of the upstream end face 211 of the impeller vane 21. Furthermore, the width Wg can be less than or equal to the width Wi.

[0033] The diameter range in which the multiple guide vanes 41 are formed is larger than the diameter range in which the upstream portion 210 of each impeller vane 21 of the compressor impeller 2 is formed. Furthermore, in this embodiment, the number of multiple guide vanes 41 is greater than the number of multiple impeller vanes 21. However, the number of multiple guide vanes 41 can also be less than or equal to the number of multiple impeller vanes 21.

[0034] As shown by the dashed lines in Figure 2, the multiple guide vanes 41 may be formed on a separate component 3E from the first housing 3A.

[0035] (Positional relationship between guide vane 41 and impeller vane 21) As shown in Figure 3, the multiple impeller vanes 21 are formed at equal intervals in the circumferential direction C to ensure stable rotation. In other words, the multiple impeller vanes 21 are formed with a uniform formation pitch in the circumferential direction C. In contrast, as shown in Figure 4, the multiple guide vanes 41 are formed with an uneven formation pitch θ so as not to be arranged at equal intervals in the circumferential direction C, in order to improve noise, vibration, etc.

[0036] Specifically, when the compressor impeller 2 rotates, at least one of the forming pitches θ in the circumferential direction C between the multiple guide vanes 41 is different from the other forming pitches θ, so that the center position Og in the circumferential direction C at the inner end face 411 of the guide vane 41 and the width Wi range in the circumferential direction C at the upstream end face 211 of the impeller vane 21 do not overlap at multiple locations in the circumferential direction C simultaneously. "Do not overlap at multiple locations in the circumferential direction C simultaneously" means that when the compressor impeller 2 rotates, a state in which the center position Og and the width Wi range overlap at only one location in the circumferential direction C is repeatedly formed.

[0037] Here, the impeller vane 21 that compares the range of the width Wi in the circumferential direction C with the center position Og in the circumferential direction C at the inner circumferential end face 411 of the guide vane 41 is assumed to exclude the auxiliary impeller vane 22.

[0038] When multiple guide vanes 41 and multiple impeller vanes 21 are formed with a uniform formation pitch in the circumferential direction C, if the number of guide vanes 41 and the number of impeller vanes 21 have a common divisor other than 1, then when the compressor impeller 2 rotates, the center position Og in the circumferential direction C at the inner circumferential end face 411 of the guide vanes 41 and the width Wi range in the circumferential direction C at the upstream end face 211 of the impeller vanes 21 will overlap at multiple locations in the circumferential direction C simultaneously. For example, as shown in Figure 8, if there are six impeller vanes 21 arranged at equal intervals and nine guide vanes 41 arranged at equal intervals, then during one rotation of the compressor impeller 2, the center position Og in the circumferential direction C on the inner end face 411 of the guide vanes 41 and the width Wi of the circumferential direction C on the upstream end face 211 of the impeller vanes 21 will repeatedly overlap at three locations simultaneously in the circumferential direction C. In this case, noise, vibration, etc. are likely to occur when the compressor impeller 2 rotates.

[0039] To prevent the center position Og in the circumferential direction C at the inner end face 411 of the guide vane 41 and the width Wi range in the circumferential direction C at the upstream end face 211 of the impeller vane 21 from overlapping at multiple locations in the circumferential direction C, it is conceivable to make the relationship between the number of guide vanes 41 and the number of impeller vanes 21 such that there are no common divisors other than 1. For example, if the number of impeller vanes 21 is 6, then the relationship of having 11 guide vanes 41 corresponds to this. Because there are no common divisors other than 1 between 6 and 11, the center position Og in the circumferential direction C at the inner end face 411 of the guide vane 41 and the width Wi range in the circumferential direction C at the upstream end face 211 of the impeller vane 21 will not overlap at multiple locations in the circumferential direction C simultaneously during one rotation of the compressor impeller 2.

[0040] However, if the number of guide vanes 41 is increased to 11, the volume of each individual space 42 formed between the guide vanes 41 in the circumferential direction C becomes smaller. In this case, the flow rate of air A circulated to the upstream section 210 of the impeller vane 21 by the circulation channel 33 and the guide vanes 41 decreases, and it may not be possible to secure the flow rate of air A necessary to suppress surging.

[0041] Therefore, in this embodiment, when the number of guide vanes 41 and the number of impeller vanes 21 have a common divisor other than 1, the guide vanes 41 are formed with a non-uniform formation pitch θ. In this embodiment, as shown in Figure 6, when the number of impeller vanes 21 is 6 and the number of guide vanes 41 is 9, the guide vanes 41 are formed with a non-uniform formation pitch θ1, θ2, θ3, θ4.

[0042] As shown in Figure 8, when there are 6 impeller vanes 21 and 9 guide vanes 41, if the guide vanes 41 are formed with a uniform formation pitch θ, the formation pitch θ will be 40°. This configuration in Figure 8 will be referred to as comparative configuration 1. In this case, the center position Og in the circumferential direction C on the inner end face 411 of the guide vane 41 and the width Wi of the circumferential direction C on the upstream end face 211 of the impeller vane 21 (hereinafter also referred to as the "specific range") overlap simultaneously at three locations. That is, the three guide vanes 41A, 41B, and 41C of a certain set of guide vane groups 410 overlap simultaneously in the specific range. This overlap at three locations occurs sequentially for three sets of guide vane groups 410.

[0043] Therefore, in the case of comparative form 1 (Figure 8), the formation pitch is adjusted so that for each of the three sets of guide vane groups 410, the three guide vanes 41A, 41B, and 41C whose positions in the circumferential direction C overlap with a specific range do not overlap with the specific range at the same time. In other words, as shown in Figure 6, compared to the state in Figure 8, the position of one of the three guide vanes 41A, 41B, and 41C, guide vane 41A, is shifted by a predetermined amount to one side of the circumferential direction C, and the position of the other guide vane 41B is shifted by a predetermined amount to the other side of the circumferential direction C. The guide vanes 41A and 41B before the position shift (i.e., the state in Figure 8) are shown by dashed lines. As a result, when the compressor impeller 2 rotates, the center position Og in the circumferential direction C at the inner circumferential end face 411 of the guide vane 41 and the width Wi range in the circumferential direction C at the upstream end face 211 of the impeller vane 21 do not overlap at multiple locations in the circumferential direction C at the same time.

[0044] In this embodiment, at least one of the formation pitches θ in the circumferential direction C between the multiple guide vanes 41 is made to differ from the other formation pitches θ within the range of the width Wg of the circumferential direction C at the inner circumferential end face 411 of the guide vane 41. That is, for each of the three sets of guide vane groups 410, of the three guide vanes 41A, 41B, and 41C whose positions in the circumferential direction C overlap with a specific range in the state shown in Figure 8, one guide vane 41A is shifted to one side of the circumferential direction C within the range of the width Wg of the circumferential direction C at the inner circumferential end face 411, and the other guide vane 41B is shifted to the other side of the circumferential direction C within the range of the width Wg of the circumferential direction C at the inner circumferential end face 411.

[0045] If the width Wg of each guide vane 41 changes in the axial direction (height direction) L, the width Wg of each guide vane 41 should be the average value. Also, in the state shown in Figure 8, of the three guide vanes 41A, 41B, and 41C whose position in the circumferential direction C overlaps with a specific range, one guide vane 41A may be shifted to one side of the circumferential direction C within the range of the width Wg of the circumferential direction C at the inner circumferential end face 411, and the other guide vane 41B may be shifted to one side of the circumferential direction C by an amount different from the amount by which the guide vane 41A was shifted, within the range of the width Wg of the circumferential direction C at the inner circumferential end face 411.

[0046] The amount by which the formation pitch θ of the guide vanes 41 is shifted in the circumferential direction C may be within ±5% of the reference formation pitch, which is obtained by dividing 360° (the circumference of the compressor housing 3) by the number of guide vanes 41. In this embodiment, since the reference formation pitch is 40°, the formation pitch θ of the guide vanes 41 may be shifted within a range of ±2°.

[0047] As shown in Figure 6, in order to more effectively reduce the generation of noise, vibration, etc. when the compressor impeller 2 rotates, it is preferable that the range of width Wg in the circumferential direction C of the inner end face 411 of the guide vane 41 and the range of width Wi in the circumferential direction C of the upstream end face 211 of the impeller vane 21 do not overlap at multiple locations in the circumferential direction C simultaneously. Here, if the width Wg in the circumferential direction C of the inner end face 411 of the guide vane 41 differs with respect to the axial direction L, it is preferable that at the height position where the width Wg is maximum (position in the axial direction L), the range of width Wg and the range of width Wi do not overlap at multiple locations in the circumferential direction C simultaneously.

[0048] However, if the amount by which the formation pitch θ of the guide vanes 41 is shifted in the circumferential direction C is made excessively large, as shown in θ5, θ6, and θ7 of Figure 7, the volume of the space 42 formed between the guide vanes 41 will change drastically depending on the position, which may reduce the effect of reducing surging when the compressor impeller 2 rotates.

[0049] The number of guide vanes 41 and the number of impeller vanes 21 can be combined in various ways. For example, the number of guide vanes 41 may be 12 and the number of impeller vanes 21 may be 8. Alternatively, for example, the number of guide vanes 41 may be 10 and the number of impeller vanes 21 may be 6.

[0050] Furthermore, to generalize the example in Figure 6, for each of the multiple sets of guide vane groups 410, the center position Og of at least one of the multiple guide vanes 41 whose center position Og in the circumferential direction C on the inner circumferential end face 411 simultaneously overlaps in the circumferential direction C with the width Wi range in the circumferential direction C on the upstream end face 211 of the impeller vane 21 should be shifted in the circumferential direction C from the formation position of the reference formation pitch.

[0051] Among the formation pitches θ in the circumferential direction C between multiple guide vanes 41, some may be the same. Alternatively, all of the formation pitches θ in the circumferential direction C between multiple guide vanes 41 may be different from one another.

[0052] (Effects and Benefits) In the compressor 1 for the turbocharger of this embodiment, the formation pitch θ of at least one of the multiple guide vanes 41 is made non-uniform. Specifically, the formation pitch θ in the circumferential direction C between some guide vanes 41 is shifted by a predetermined amount in the circumferential direction C from the reference formation pitch. With this configuration, when the compressor impeller 2 rotates, the center position Og in the circumferential direction C of the inner circumferential end face 411, which is the formation position of the guide vanes 41, and the width Wi range in the circumferential direction C of the upstream end face 211, which is the formation position of the impeller vanes 21, do not coincide simultaneously at multiple locations in the circumferential direction C.

[0053] The noise and vibrations during the rotation of the compressor impeller 2 are thought to be caused by air A flowing into the gap formed between the inner circumferential end face 411 of the guide vane 41 and the upstream end face 211 of the impeller vane 21 when they come into close proximity. Therefore, it is thought that the center position Og in the circumferential direction C of the inner circumferential end face 411 of the guide vane 41 and the width Wi of the circumferential direction C of the upstream end face 211 of the impeller vane 21 do not coincide simultaneously at multiple points in the circumferential direction C, making it less likely for resonance phenomena based on the natural frequency of the compressor impeller 2 to occur.

[0054] Therefore, with the compressor 1 for the turbocharger in this form, noise, vibration, etc. due to resonance phenomena can be less likely to occur when the compressor impeller 2 rotates.

[0055] <Embodiment 2> The compressor 1 for the turbocharger in this embodiment has a flow path partition 335 that divides the circulation flow path 33 in the circumferential direction, as shown in Figures 9 to 12. Multiple flow path partitions 335 are formed in a manner that is arranged in the circumferential direction. At least one of the formation pitches in the circumferential direction between the multiple flow path partitions 335 is different from the formation pitches of the other parts.

[0056] In this embodiment, the flow path partition 335 is located in the annular flow path section 331 of the circulating flow path 33 at a position L2 downstream in the axial direction L from the outlet communication section 333, as shown in Figures 9 and 10. The flow path partition 335 has a notch 336 at a position opposite to the inlet communication section 332. However, the specific shape and formation location of the flow path partition 335 are not limited to these, and other shapes and formation locations are also possible as long as they have the function of partitioning at least a part of the circulating flow path 33 in the circumferential direction. For example, the flow path partition 335 may be formed only between the inlet communication section 332 and the outlet communication section 333 in the axial direction L.

[0057] In this embodiment, as shown in Figure 12, the flow channel partitions 335 are formed at three locations in the circumferential direction. In this case, three circumferential spacings are formed between the multiple flow channel partitions 335, but for example, as shown in Figure 12, one formation pitch α1 is formed to be different from the other formation pitches α2 and α3.

[0058] The compressor impeller 2 has the same configuration as in Embodiment 1. That is, the multiple impeller vanes 21 are formed arranged at equal intervals in the circumferential direction. The relationship between the number of flow path partitions 335 and the number of impeller vanes 21 has a common divisor other than 1. That is, for example, as shown in Figure 12, the number of impeller vanes 21 is 6 and the number of flow path partitions 335 is 3, and the relationship between the two has a common divisor other than 1 (in this case, "3").

[0059] When the compressor impeller 2 rotates, the configuration ensures that the center position Of in the circumferential direction C of the flow channel partition 335 and the width range in the circumferential direction C of the upstream end face 211 (see Figure 3) of the impeller vane 21 do not overlap at multiple locations in the circumferential direction C simultaneously. To achieve this configuration, at least one of the formation pitches in the circumferential direction C between the multiple flow channel partitions 335 is formed to be different from the other formation pitches.

[0060] If, as shown in Figure 13, three flow path partitions 335 are provided at equal intervals in the circumferential direction, the formation pitch α0 of the flow path partitions 335 will be 120°. This configuration in Figure 13 will be referred to as comparative configuration 2. In this case, the center position Of in the circumferential direction C of the flow path partition 335 and the width Wi of the circumferential direction C at the upstream end face 211 of the impeller vane 21 (hereinafter also referred to as the "specific range") overlap at three locations simultaneously. When the center position Of in the circumferential direction C of the flow path partition 335 and the specific range of the impeller vane 21 overlap at multiple locations simultaneously in the circumferential direction C, it can become a source of noise and vibration.

[0061] Therefore, in Embodiment 2, as shown in Figure 12, the flow channel partitions 335 are arranged such that at least one of the formation pitches in the circumferential direction C between the multiple flow channel partitions 335 (α1 in this embodiment) is different from the other formation pitches (α2, α3 in this embodiment).

[0062] In Embodiment 2, the connecting portion 334 (see Figure 4) shown in Embodiment 1 is omitted, and the above-mentioned flow path partition portion 335 is provided instead. Otherwise, it is the same as in Embodiment 1. Note that, among the reference numerals used in Embodiment 2 and later, those that are the same as those used in the previously described embodiments represent the same components, etc., as in the previously described embodiments, unless otherwise specified.

[0063] In the compressor 1 for the turbocharger of this embodiment, the formation pitch of at least one of the multiple flow path partitions 335 is made non-uniform. This configuration prevents the center position Of of the flow path partition 335 and the width Wi of the circumferential C of the impeller vane 21 from simultaneously coinciding at multiple points in the circumferential C when the compressor impeller 2 rotates.

[0064] Therefore, with the compressor 1 for the turbocharger in this form, noise, vibration, etc. due to resonance phenomena can be less likely to occur when the compressor impeller 2 rotates.

[0065] Furthermore, in this embodiment, the formation pitch of at least one of the multiple guide vanes 41 is made non-uniform, and the formation pitch of at least one of the multiple flow path partitions 335 is also made non-uniform. This makes it possible to suppress noise and vibration more effectively.

[0066] Furthermore, it is also possible to configure the system so that the formation pitch of the multiple guide vanes 41 is uniform, while the formation pitch of at least one of the multiple flow path partitions 335 is non-uniform. In this case as well, noise and vibration can be suppressed compared to the case where the formation pitch of the multiple guide vanes 41 and the formation pitch of the multiple flow path partitions 335 are both uniform.

[0067] <Embodiment 3> As shown in Figures 14 and 15, the compressor 1 for the turbocharger in this embodiment has a plurality of rectifying fins 311 at the intake port 31 on the upstream side L1 of the shroud flow path 32. The plurality of rectifying fins 311 are arranged in a circumferential direction. At least one of the formation pitches in the circumferential direction C between the plurality of rectifying fins 311 is different from the formation pitches of the other fins.

[0068] In this embodiment, the rectifier fins 311 are formed at the intake port 31 located upstream L1 from the guide vane 41. The rectifier fins 311 are arranged substantially parallel to the axial L and radial R directions. The rectifier fins 311 have the function of rectifying the airflow introduced into the shroud channel 32.

[0069] In this embodiment, as shown in Figure 15, the rectifying fins 311 are formed at eight locations in the circumferential direction. In this case, eight circumferential spacings are formed between the multiple flow channel partitions 335, but for example, as shown in Figure 15, the eight formation pitches (β1 to β3, etc.) are uneven.

[0070] The compressor impeller 2 has the same configuration as in Embodiment 1. That is, the multiple impeller vanes 21 are formed arranged at equal intervals in the circumferential direction. The relationship between the number of rectifier fins 311 and the number of impeller vanes 21 has a common divisor other than 1. That is, for example, as shown in Figure 15, the number of impeller vanes 21 is 6 and the number of rectifier fins 311 is 8, and the relationship between the two has a common divisor other than 1 (in this case, "2").

[0071] When the compressor impeller 2 rotates, the configuration ensures that the center position Or in the circumferential direction C of the rectifier fin 311 and the width range in the circumferential direction C of the upstream end face 211 of the impeller vane 21 (see Figure 3) do not overlap at multiple locations in the circumferential direction C simultaneously. To achieve this configuration, at least one of the formation pitches in the circumferential direction C between the multiple rectifier fins 311 is formed to be different from the other formation pitches.

[0072] If, as shown in Figure 16, eight rectifier fins 311 are arranged at equal intervals in the circumferential direction, the formation pitch β0 of the rectifier fins 311 will be 45°. This configuration in Figure 16 will be referred to as comparative configuration 3. In this case, the center position Or of the circumferential direction C of the rectifier fins 311 and the width Wi of the circumferential direction C on the upstream end face 211 of the impeller vane 21 (hereinafter also referred to as the "specific range") overlap at two locations simultaneously. When the center position Or of the circumferential direction C of the rectifier fins 311 and the specific range of the impeller vane 21 overlap at multiple locations simultaneously in the circumferential direction C, it can become a source of noise and vibration.

[0073] Therefore, in Embodiment 3, as shown in Figure 15, the rectifier fins 311 are arranged such that at least one of the formation pitches in the circumferential direction C between the plurality of rectifier fins 311 (for example, β1) is different from the other formation pitches (for example, β2, β3). Other aspects are the same as in Embodiment 1.

[0074] In the compressor 1 for the turbocharger of this embodiment, the formation pitch of at least one of the multiple rectifier fins 311 is made non-uniform. This configuration ensures that when the compressor impeller 2 rotates, the center position Or of the rectifier fins 311 and the width Wi of the circumferential C of the impeller vane 21 do not coincide simultaneously at multiple points in the circumferential C.

[0075] Therefore, with the compressor 1 for the turbocharger in this form, noise, vibration, etc. due to resonance phenomena can be less likely to occur when the compressor impeller 2 rotates.

[0076] Furthermore, in this embodiment, the formation pitch of at least one of the multiple guide vanes 41 is made non-uniform, and the formation pitch of at least one of the multiple rectifier fins 311 is also made non-uniform. This makes it possible to suppress noise and vibration more effectively.

[0077] Furthermore, it is also possible to configure the system so that the formation pitch of the multiple guide vanes 41 is uniform, while the formation pitch of at least one of the multiple rectifier fins 311 is non-uniform. In this case as well, noise and vibration can be suppressed compared to the case where the formation pitch of the multiple guide vanes 41 and the formation pitch of the multiple rectifier fins 311 are both uniform.

[0078] Alternatively, this embodiment can be applied to a compressor housing for a turbocharger that does not have a circulation channel 33.

[0079] Furthermore, for example, a configuration combining Embodiment 2 and Embodiment 3 can be used. In this case, the noise and vibration suppression effect can be obtained even more effectively.

[0080] The present invention is not limited to these embodiments, and further different embodiments can be constructed without departing from the spirit of the invention. Furthermore, the present invention includes various modifications, modifications within the equivalent range, and so on. [Explanation of Symbols]

[0081] 1 Compressor 2 Compressor propellers 21 Imperaven 210 Upstream section 3 Compressor Housing 31 Inlet 311 Rectifying Fins 32 Shroud channel 33 Circulation channels 335 Flow channel partition 41 Guide vanes 42 Space section

Claims

1. A compressor impeller having multiple impeller vanes arranged in the circumferential direction, The compressor housing comprises a shroud passage in which the compressor impeller is housed in a rotatable state, and a circulation passage formed on the outer circumference of the shroud passage, which allows a portion of the air flowing through the shroud passage to be recirculated to the upstream side of the shroud passage. At the outlet of the circulation channel connected to the shroud channel, a plurality of guide vanes are formed in a circumferential direction to introduce the air flowing through the circulation channel to the upstream part of the impeller vane. At least one of the circumferential formation pitches between the multiple guide vanes differs from the other formation pitches. Multiple impeller vanes are formed and arranged at equal intervals in the circumferential direction. The guide vane is formed at an upstream position in the axial direction of the circulation channel, projecting radially from the outer circumference to the inner circumference and axially from the upstream to the downstream side. The relationship between the number of guide vanes and the number of impeller vanes is such that there is a common divisor other than 1. A compressor for a turbocharger, wherein, when the compressor impeller rotates, at least one of the circumferential forming pitches between a plurality of guide vanes is different from the other forming pitches, such that the circumferential center position on the inner end face of the guide vanes and the circumferential width range on the upstream end face of the impeller vanes do not overlap at multiple locations in the circumferential direction simultaneously.

2. A compressor for a turbocharger according to claim 1, wherein at least one of the circumferential forming pitches between a plurality of guide vanes differs from the other forming pitches within the range of the circumferential width at the inner circumferential end face of the guide vane.

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