Inlet guide vane

Abstract

To suppress peeling of fluid flow in an over-open state of an IGV.SOLUTION: An inlet guide vane 100 includes a plurality of vanes 8 arranged in a circumferential direction. Each angle of the plurality of vanes 8 is changeable relative to the main flow, grips a full-open state in which a cross-sectional area of the main flow when seen in the direction along the main flow is maximum, and is adjustable on both sides. Each of the plurality of vanes 8 includes a first blade piece 81 and a second blade piece 82. When an angle tilts to one side from the full-open state beyond a limit at a prescribed angle, a gap appears between the first blade piece and the second blade piece; the gap closes when the angle is not beyond the limit.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to inlet guide vanes. [Background technology]

[0002] The compressor may include a variable inlet guide vane (IGV) located upstream of the impeller (see, for example, Patent Document 1). The IGV is capable of adjusting the cross-sectional area of ​​the flow passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-5092 A Summary of the Invention [Problem to be solved by the invention]

[0004] As the IGVs switch from fully closed to fully open, the flow rate increases. As the IGVs tilt further away from the fully open position, the flow rate increases further. However, if the IGVs move too far from the fully open position, the fluid flow separates from the vanes and the compressor becomes less efficient.

[0005] The present disclosure aims to provide an inlet guide vane that can suppress separation of fluid flow when an IGV is in an over-open state. [Means for solving the problem]

[0006] An inlet guide vane according to one embodiment of the present disclosure is an inlet guide vane provided in an intake flow path of a compressor, comprising a plurality of vanes arranged in a circumferential direction, the angle of each of the plurality of vanes being changeable relative to a main flow, the angle being adjustable on both sides of a fully open state in which the cross-sectional area of ​​the main flow is maximum when viewed in a direction along the main flow, each of the plurality of vanes including a first wing and a second wing, and when the angle exceeds a predetermined limit and tilts to one side from the fully open state, a gap is created between the first wing and the second wing, and when the angle does not exceed the limit, the gap is closed.

[0007] The gap may gradually increase as the vane moves from the limit toward the fully open condition.

[0008] The second wing may be rotatable away from the first wing.

[0009] Each of the multiple vanes may include a first shaft supporting a first wing piece and rotatable about a first vane axis; a first gear arranged around the first shaft and fixed to an inner wall of a housing that accommodates the inlet guide vane, the first gear including a plurality of first teeth only in a predetermined angular range; a second shaft supporting a second wing piece and supported by the first shaft for rotation about a second vane axis; and a second gear arranged around the second shaft and fixed to the second shaft, the second gear including a plurality of second teeth that engage with the first teeth of the first gear, the first teeth and the second teeth engaging with each other, and rotating about the second vane axis when the first shaft rotates.

[0010] The second wing may be movable away from the first wing while maintaining an angle relative to the first wing.

[0011] Each of the multiple vanes may include a first shaft supporting a first wing piece and rotatable about a first vane axis, a second shaft supporting a second wing piece and supported by the first shaft, the second shaft being movable away from the first vane axis, and a cam arranged around the first shaft and fixed to an inner wall of a housing that accommodates the inlet guide vane, the cam pressing against the second shaft within a predetermined angular range.

[0012] Each of the plurality of vanes may include a lid rotatably supported on one of the first and second wing pieces, the lid opening the gap when the vane is tilted beyond the limit and closing the gap when the vane is positioned between the fully closed state and the limit.

[0013] The first and second winglets may be separated in the chord length direction. Effect of the Invention

[0014] According to the present disclosure, separation of fluid flow when the IGV is in an over-open state can be suppressed. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a turbocharger including an inlet guide vane according to a first embodiment. [Diagram 2] FIG. 2 is a schematic enlarged cross-sectional view of a portion A in FIG. [Diagram 3] FIG. 3 shows the vanes in the fully closed state, the fully open state, and the over-open state as viewed from the direction of the arrow B in FIG. [Figure 4] FIG. 4 shows the first gear and the second gear as viewed from the direction of arrow B in FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view showing an inlet guide vane according to the second embodiment. [Figure 6] FIG. 6 shows the vanes in the fully closed state, the fully open state, and the over-open state as viewed from the direction of the arrow B in FIG. [Figure 7]FIG. 7 shows the support plate and the cam from the direction of arrow B in FIG. [Figure 8] FIG. 8 is a schematic cross-sectional view showing an inlet guide vane according to the third embodiment. [Figure 9] FIG. 9 shows the vanes in the fully closed state, the fully open state, and the over-open state as viewed from the direction of the arrow B in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present disclosure are omitted from the drawings.

[0017] FIG. 1 is a schematic cross-sectional view showing a turbocharger TC including an inlet guide vane 100 according to a first embodiment. In this embodiment, a centrifugal compressor C1 is applied to the turbocharger TC. In other embodiments, the centrifugal compressor C1 may be applied to other devices or may be an independent device. For example, the turbocharger TC is applied to an engine. The turbocharger TC includes a housing 1, a shaft 2, a turbine impeller 3, and a compressor impeller 4.

[0018] As described below, the shaft 2, the turbine impeller 3, and the compressor impeller 4 rotate integrally with each other. Therefore, in this disclosure, the axial direction, radial direction, and circumferential direction of the shaft 2, the turbine impeller 3, and the compressor impeller 4 may be simply referred to as the "axial direction," the "radial direction," and the "circumferential direction," respectively, unless otherwise specified. Also, in this disclosure, the central axis of the shaft 2, the turbine impeller 3, and the compressor impeller 4 may be simply referred to as the "central axis."

[0019] The housing 1 includes a bearing housing 5, a turbine housing 6, and a compressor housing 7. One axial end of the bearing housing 5 is connected to the turbine housing 6 by a fastener such as a G coupling. The other axial end of the bearing housing 5 is connected to the compressor housing 7 by a fastener such as a fastening bolt.

[0020] The bearing housing 5 includes a bearing hole 51. The bearing hole 51 extends in the axial direction within the bearing housing 5. In this embodiment, the bearing hole 51 accommodates a pair of rolling bearings B1, B2. The rolling bearings B1, B2 rotatably support the shaft 2. In other embodiments, other radial bearings, such as semi-floating bearings or full-floating bearings, may be used instead of the rolling bearings B1, B2.

[0021] A turbine impeller 3 is provided at a first end of the shaft 2 in the axial direction. The turbine impeller 3 is rotatably housed in a turbine housing 6. The turbine impeller 3 rotates integrally with the shaft 2.

[0022] A compressor impeller 4 is provided at a second end of the shaft 2 in the axial direction. The compressor impeller 4 is rotatably housed in a compressor housing 7. The compressor impeller 4 rotates integrally with the shaft 2.

[0023] The compressor housing 7 includes an air intake 71 at an end opposite to the bearing housing 5 in the axial direction. The air intake 71 is connected to an air cleaner (not shown). The bearing housing 5 and the compressor housing 7 define a diffuser passage 72 therebetween. The diffuser passage 72 expands in the radial direction. The diffuser passage 72 has a generally annular shape. The diffuser passage 72 communicates with the air intake 71 via the compressor impeller 4.

[0024] The compressor housing 7 includes a compressor scroll passage 73. The compressor scroll passage 73 is located radially outward of the compressor impeller 4. The compressor scroll passage 73 communicates with the diffuser passage 72. The compressor scroll passage 73 also communicates with an intake port of an engine (not shown).

[0025] The compressor housing 7 is provided with a variable inlet guide vane (IGV) 100. The IGV 100 adjusts the cross-sectional area of ​​the main flow passage inside the compressor housing 7. In this embodiment, the main flow direction is the axial direction, which is also the direction in which the flow passage in the portion of the compressor housing 7 where the inlet guide vane (IGV) 100 is attached extends. The IGV 100 will be described in detail later.

[0026] When the compressor impeller 4 rotates, air is drawn into the compressor housing 7 through the intake port 71. The drawn air is accelerated and pressurized by centrifugal force as it passes through the blades of the compressor impeller 4. The air is further pressurized in the diffuser passage 72 and the compressor scroll passage 73. The pressurized air flows out from a discharge port (not shown) and is led to an intake port of the engine (not shown). In the turbocharger TC, a portion including the compressor impeller 4 and the compressor housing 7 functions as a centrifugal compressor C1.

[0027] The turbine housing 6 includes a discharge port 61 at an end opposite to the bearing housing 5 in the axial direction. The discharge port 61 is connected to an exhaust gas purification device (not shown). The turbine housing 6 includes a flow path 62 and a turbine scroll flow path 63. The turbine scroll flow path 63 is located radially outward from the turbine impeller 3. The flow path 62 is located between the turbine impeller 3 and the turbine scroll flow path 63. The turbine scroll flow path 63 communicates with the flow path 62. The flow path 62 communicates with the discharge port 61 via the turbine impeller 3.

[0028] The turbine scroll passage 63 communicates with a gas inlet (not shown). The gas inlet receives exhaust gas discharged from an exhaust manifold (not shown) of the engine. The exhaust gas is guided from the gas inlet to the turbine scroll passage 63, and is further guided to the discharge port 61 via the passage 62 and the turbine impeller 3. The exhaust gas rotates the turbine impeller 3 as it passes through the blades of the turbine impeller 3.

[0029] The rotational force of the turbine impeller 3 is transmitted to the compressor impeller 4 via the shaft 2. When the compressor impeller 4 rotates, the air from the intake port 71 is pressurized as described above. In this manner, the pressurized air is guided to the intake port of the engine. In the turbocharger TC, a portion including the turbine impeller 3 and the turbine housing 6 functions as the turbine T.

[0030] Next, we will explain about IGV100.

[0031] The IGV 100 is disposed upstream of the compressor impeller 4 in an intake passage within the compressor housing 7. The IGV 100 includes a plurality of vanes 8 disposed along the circumferential direction.

[0032] 2 is a schematic enlarged cross-sectional view of part A in FIG. 1. The vane 8 protrudes radially inward from the inner wall 74 of the compressor housing 7. The vane 8 is rotatable about a first vane axis X1. The first vane axis X1 intersects with the axial direction. Specifically, the first vane axis X1 is perpendicular to the axial direction. In other words, the first vane axis X1 is parallel to the radial direction. For example, the multiple vanes 8 are rotated simultaneously by an actuator such as a motor via a component such as an annular plate (not shown).

[0033] FIG. 3 shows vane 8 in a fully closed state S1, a fully open state S2 and an over-open state S3 as viewed from the direction of arrow B in FIG. 2. In FIG. 3, vane 8 is viewed from the radially inner side. The upper diagram shows vane 8 in a fully closed state S1. The middle diagram shows vane 8 in a fully open state S2. The lower diagram shows vane 8 in an over-open state S3. The axial direction is indicated as Da and the circumferential direction is indicated as Dc. In each of the states S1, S2 and S3, the direction of rotation of compressor impeller 4 (not shown in FIG. 3) is indicated as Di. In FIG. 3, fluid flows from left to right.

[0034] In the fully closed state S1, the vane 8 (the chord length direction of the vane 8) is parallel to the circumferential direction Dc. Therefore, in the fully closed state S1, the angle α between the vane 8 and the circumferential direction Dc is zero. In the fully closed state S1, the multiple vanes 8 are adjacent to each other or in contact with each other to form a ring. In the fully closed state S1, the cross-sectional area of ​​the flow path is minimum.

[0035] The vanes 8 rotate from a fully closed state S1 to a fully open state S2 so as to form a space between adjacent vanes 8. Specifically, when the vanes 8 are located between the fully closed state S1 and the fully open state S2, the vanes 8 are rotated so that the flow of fluid entering the space between adjacent vanes 8 is bent in the direction of rotation Di of the compressor impeller 4. In the example of Fig. 3, the vanes 8 rotate clockwise from the fully closed state S1 to the fully open state S2.

[0036] In the fully open state S2, the vane 8 (the chord length direction of the vane 8) is perpendicular to the circumferential direction Dc. Therefore, in the fully open state S2, the angle α between the vane 8 and the circumferential direction Dc is 90 degrees. In the fully open state S2, the cross-sectional area of ​​the flow passage is at a maximum.

[0037] The vane 8 further rotates from the fully open state S2 to the over-open state S3. In the over-open state S3, the vane 8 tilts from the fully open state S2 to the opposite side to the fully closed state S1. Therefore, in the over-open state S3, the angle α between the vane 8 and the circumferential direction Dc is greater than 90 degrees. The cross-sectional area of ​​the flow passage in the over-open state S3 is smaller than the cross-sectional area of ​​the flow passage in the fully open state S2, but larger than the cross-sectional area of ​​the flow passage in the fully closed state S1.

[0038] As the rotation speed of the compressor impeller 4 increases, the vane 8 rotates from the fully closed state S1 to the fully open state S2, and the flow rate of the fluid increases. As the rotation speed of the compressor impeller 4 further increases, the vane 8 further rotates from the fully open state S2 to the over-open state S3, and the flow rate of the fluid further increases. However, in the over-open state S3, the flow of the fluid entering the space between the adjacent vanes 8 is bent in the opposite direction to the rotation direction Di of the compressor impeller 4. Therefore, if the angle α of the vane 8 in the over-open state S3 increases excessively, the flow of the fluid separates from the vane 8, and the efficiency of the centrifugal compressor C1 decreases. In the present disclosure, in order to suppress such separation, a gap g is formed in the vane 8 when the vane 8 tilts from the fully open state S2 to the opposite side to the fully closed state S1 beyond the limit L. The limit L is located at a predetermined angle (for example, 10 degrees) from the fully open state S2 to the opposite side to the fully closed state S1. The predetermined angle is not limited to 10 degrees and may be another value. Therefore, the angle of the limit L (the angle of the limit L from the fully closed state S1) is greater than 90 degrees (for example, 100 degrees). The angle of the limit L is not limited to 100 degrees and may be another value. For example, the limit L may be obtained by analysis or experiment as the angle at which the flow of the fluid starts to separate from the vane 8.

[0039] In this embodiment, the vane 8 includes an upstream wing piece (first wing piece, second wing piece) 81 and a downstream wing piece (first wing piece, second wing piece) 82. When the upstream wing piece 81 and the downstream wing piece 82 are combined with each other, the upstream wing piece 81 and the downstream wing piece 82 define a wing shape and function as one wing. The upstream wing piece 81 and the downstream wing piece 82 are divided in the chord length direction. In the fully open state S2, the upstream wing piece 81 is located upstream of the downstream wing piece 82. The contact surface between the upstream wing piece 81 and the downstream wing piece 82 is inclined with respect to the wing thickness direction so as not to hinder the rotation of the downstream wing piece 82 described later.

[0040] In this embodiment, the vane 8 is configured such that the gap g gradually increases as the vane 8 rotates further from the limit L. Specifically, in this embodiment, the downstream vane piece 82 is rotatable away from the upstream vane piece 81 about a second vane axis X2 that is parallel to and spaced apart from the first vane axis X1.

[0041] 2, more specifically, in this embodiment, the vane 8 includes a first shaft 83, a second shaft 84, a first gear 85, and a second gear 86. The vane 8 may further include other components.

[0042] The first shaft 83 is rotatable about the first vane axis X1. The first shaft 83 penetrates the compressor housing 7 from the inside to the outside. For example, the first shafts 83 of the multiple vanes 8 are rotated simultaneously by an actuator such as a motor via a component such as an annular plate (not shown).

[0043] The first shaft 83 supports the upstream wing piece 81. The upstream wing piece 81 is fixed to the first shaft 83. Therefore, the upstream wing piece 81 rotates integrally with the first shaft 83, and does not rotate relative to the first shaft 83.

[0044] For example, the first shaft 83 includes a support plate 83a inside the compressor housing 7. The support plate 83a extends perpendicular to the first vane axis X1. The support plate 83a extends on both sides from the first vane axis X1. For example, the upstream winglet 81 is fixed to the support plate 83a on one side relative to the first vane axis X1. For example, the upstream winglet 81 may include a protrusion that passes through the support plate 83a and may be fixed by a part such as a nut or a rivet.

[0045] The second shaft 84 is rotatably supported by the first shaft 83. For example, the second shaft 84 penetrates the support plate 83a on the other side with respect to the first vane axis X1. For example, a bearing (not shown) may be arranged between the second shaft 84 and the support plate 83a. The second shaft 84 extends parallel to the first vane axis X1. The second vane axis X2 corresponds to the central axis of the second shaft 84. The downstream blade 82 is fixed to the second shaft 84. Therefore, the downstream blade 82 rotates integrally with the second shaft 84. For example, the downstream blade 82 may be formed integrally with the second shaft 84, or may be formed separately from the second shaft 84 and connected to the second shaft 84.

[0046] The first gear 85 is disposed around the first shaft 83. The first gear 85 is disposed concentrically with the first shaft 83. The first shaft 83 passes through the first gear 85. A gap may be formed between the first gear 85 and the first shaft 83. The first gear 85 is fixed to the inner wall 74 of the compressor housing 7. Therefore, even if the first shaft 83 rotates, the first gear 85 does not rotate integrally with the first shaft 83.

[0047] The second gear 86 is disposed around the second shaft 84. The second gear 86 is fixed to the second shaft 84. Therefore, the second gear 86 rotates integrally with the second shaft 84 and the downstream wing piece 82. Furthermore, when the first shaft 83 rotates, the second gear 86 rotates (revolves) around the first gear 85 together with the second shaft 84 and the downstream wing piece 82.

[0048] FIG. 4 shows the first gear 85 and the second gear 86 as viewed from the direction of the arrow B in FIG. 2. The first gear 85 includes a plurality of first teeth 85a only in a predetermined angle range. The second gear 86 includes a plurality of second teeth 86a over the entire circumference. Specifically, the first gear 85 includes the first teeth 85a only in a range in which the first teeth 85a engage with the second teeth 86a of the second gear 86 only when the angle α of the vane 8 in the over-open state S3 exceeds the angle of the limit L, as described above. Therefore, when the vane 8 is located between the fully closed state S1 and the fully open state S2, the first teeth 85a do not engage with the second teeth 86a. Also, even if the vane 8 is in the over-open state S3, when the angle α is equal to or less than the angle of the limit L, the first teeth 85a do not engage with the second teeth 86a. When the angle α exceeds the angle of the limit L, the first teeth 85a engage with the second teeth 86a. When the first teeth 85a and the second teeth 86a engage with each other and the first shaft 83 rotates, the second gear 86 revolves around the first gear 85 and rotates integrally with the second shaft 84 and the downstream blade piece 82 about the second vane axis X2.

[0049] With reference to the over-open state S3 in FIG. 3, when the downstream wing piece 82 rotates around the second vane axis X2, the downstream wing piece 82 moves away from the upstream wing piece 81. Therefore, a gap g is formed between the upstream wing piece 81 and the downstream wing piece 82. That is, when the vane 8 is located in a range between the fully closed state S1 and the limit L, the upstream wing piece 81 and the downstream wing piece 82 are combined with each other to function as one wing, and when the vane 8 exceeds the limit L, the upstream wing piece 81 and the downstream wing piece 82 are separated from each other. According to this configuration, when the angle α increases excessively, part of the fluid flows to the back side of the vane 8 through the gap g between the upstream wing piece 81 and the downstream wing piece 82. Therefore, separation can be suppressed.

[0050] As described above, the inlet guide vane 100 according to this embodiment is provided in the intake passage of the centrifugal compressor C1 and includes a plurality of vanes 8 arranged in the circumferential direction. The angle of each of the vanes 8 can be changed with respect to the main flow, and the angle can be adjusted on both sides of the fully open state S2 in which the cross-sectional area of ​​the main flow is maximized when viewed in the direction along the main flow. Each of the vanes 8 includes an upstream wing piece 81 and a downstream wing piece 82. When the angle exceeds the limit L at a predetermined angle and tilts to one side from the fully open state S2, a gap g is generated between the upstream wing piece 81 and the downstream wing piece 82, and when the angle does not exceed the limit L, the gap g is closed. Note that the limit L is located on one side of the fully open state S2. Therefore, in the inlet guide vane 100 according to this embodiment, the angle range of the vane 8 in which the gap g is generated between the upstream wing piece 81 and the downstream wing piece 82 is narrower than the angle range of the vane 8 in which no gap is generated between the upstream wing piece 81 and the downstream wing piece 82. According to this configuration, as described above, separation can be suppressed. Therefore, the efficiency of the centrifugal compressor C1 can be prevented from decreasing. Furthermore, when the gap g is not necessary, the gap g is closed. Therefore, the efficiency of the centrifugal compressor C1 can be further prevented from decreasing.

[0051] Moreover, in the inlet guide vane 100 according to this embodiment, the gap g gradually increases as the vane 8 moves from the limit L in the direction opposite to the fully open state S2. With this configuration, the gap g increases as the flow rate of the fluid increases. Therefore, separation can be further suppressed.

[0052] Moreover, in the inlet guide vane 100 according to this embodiment, the downstream wing piece 82 can rotate away from the upstream wing piece 81. With this configuration, the inclined downstream wing piece 82 makes it easier for the fluid to be guided to the gap g. Therefore, separation can be further suppressed.

[0053] In the inlet guide vane 100 according to this embodiment, each of the vanes 8 includes a first shaft 83 supporting the upstream vane 81 and rotatable about the first vane axis X1, and a first gear 85 arranged around the first shaft 83 and fixed to the inner wall 74 of the compressor housing 7 that accommodates the inlet guide vane 100. The first gear 85 includes a plurality of first teeth 85a only in a predetermined angle range. The vane 8 also includes a second shaft 84 supporting the downstream vane 82 and supported by the first shaft 83 to be rotatable about the second vane axis X2, and a second gear 86 arranged around the second shaft 84 and fixed to the second shaft 84. The second gear 86 includes a plurality of second teeth 86a that engage with the first teeth 85a of the first gear 85, and rotates about the second vane axis X2 when the first teeth 85a and the second teeth 86a engage with each other and the first shaft 83 rotates. With this configuration, the gap g can be formed by a simple gear mechanism.

[0054] In the centrifugal compressor C1 according to the present embodiment, the upstream blade piece 81 and the downstream blade piece 82 are divided in the chord direction. With this configuration, the gap g is formed in the chord direction. Therefore, the fluid is easily guided to the gap g. Therefore, separation can be further suppressed.

[0055] Next, other embodiments will be described.

[0056] 5 is a schematic cross-sectional view showing an inlet guide vane 100 according to a second embodiment. The inlet guide vane 100 according to the second embodiment differs from the inlet guide vane 100 according to the first embodiment in the configuration of the vane 8A. Other configurations of the second embodiment may be the same as those of the first embodiment.

[0057] Fig. 6 shows the vane 8A in a fully closed state S1, a fully open state S2 and an excessively open state S3 as viewed from the direction of the arrow B in Fig. 5. In Fig. 6, like Fig. 3, the vane 8A is viewed from the radially inner side.

[0058] With reference to the over-open state S3, in this embodiment, the vane 8A is configured such that the downstream wing piece 82 moves relative to the upstream wing piece 81 while maintaining the angle relative to the upstream wing piece 81. Therefore, in this embodiment, the downstream wing piece 82 does not rotate about the second vane axis X2 (not shown in FIG. 6). Note that in this embodiment, since the downstream wing piece 82 does not rotate about the second vane axis X2, the contact surface between the upstream wing piece 81 and the downstream wing piece 82 may be parallel to the blade thickness direction.

[0059] 5, in this embodiment, vane 8A includes a cam 87 instead of first gear 85 and second gear 86. Also, in this embodiment, support plate 83a includes a long hole 83b and an elastic body 83c. In this embodiment, elastic body 83c is a coil spring. In other embodiments, elastic body 83c may be another elastic body such as rubber.

[0060] The cam 87 is disposed around the first shaft 83. The first shaft 83 passes through the cam 87. A gap may be formed between the cam 87 and the first shaft 83. The cam 87 is fixed to the inner wall 74 of the compressor housing 7. Therefore, even if the first shaft 83 rotates, the cam 87 does not rotate integrally with the first shaft 83.

[0061] The long hole 83b is formed in the support plate 83a so that its longitudinal direction is along the extension direction of the support plate 83a. One end of the elastic body 83c is attached to the second shaft 84, and the other end is attached to the inner wall of the long hole 83b. The elastic body 83c biases the second shaft 84 so as to press the second shaft 84 against one end of the long hole 83b. At the position where the second shaft 84 is pressed against one end of the long hole 83b, the upstream wing piece 81 and the downstream wing piece 82 are combined with each other to function as one wing.

[0062] Fig. 7 shows the support plate 83a and the cam 87 from the direction of the arrow B in Fig. 5. The upper figure shows the support plate 83a and the cam 87 when the vane 8A is in the fully open state S2. The lower figure shows the support plate 83a and the cam 87 when the vane 8A is in the excessively open state S3.

[0063] The cam 87 includes the protrusion 87a in a predetermined angle range. Specifically, the cam 87 includes the protrusion 87a in a range in which the protrusion 87a presses the second shaft 84 toward the elastic body 83c when the angle α of the vane 8 in the over-open state S3 exceeds the angle of the limit L. Therefore, the protrusion 87a does not press the second shaft 84 when the vane 8 is located between the fully closed state S1 and the fully open state S2. Furthermore, even if the vane 8 is in the over-open state S3, the protrusion 87a does not press the second shaft 84 when the angle α is equal to or less than the angle of the limit L. When the angle α exceeds the angle of the limit L, the protrusion 87a presses the second shaft 84 against the biasing force of the elastic body 83c. The second shaft 84 moves along the inner wall of the long hole 83b so as to move away from the first vane axis X1. When the second shaft 84 moves away from the first vane axis X1, the downstream blade 82 fixed to the second shaft 84 also moves away from the first vane axis X1, as shown in the over-open state S3 in Fig. 6. Therefore, the downstream blade 82 moves away from the upstream blade 81, and a gap g is formed between the upstream blade 81 and the downstream blade 82.

[0064] The inlet guide vane 100 as described above provides substantially the same effects as the inlet guide vane 100 according to the first embodiment. In particular, in the second embodiment, the downstream wing piece 82 can move away from the upstream wing piece 81 while maintaining the angle relative to the upstream wing piece 81. With this configuration, the downstream wing piece 82 does not protrude relative to the upstream wing piece 81. Therefore, the flow of the fluid is less likely to be obstructed.

[0065] Moreover, in the second embodiment, each of the multiple vanes 8A includes a first shaft 83 supporting the upstream blade piece 81 and rotatable about the first vane axis X1, a second shaft 84 supporting the downstream blade piece 82 and supported by the first shaft 83, the second shaft 84 being movable away from the first vane axis X1, and a cam 87 disposed around the first shaft 83 and fixed to the inner wall 74 of the compressor housing 7 accommodating the inlet guide vane 100, the cam 87 pressing the second shaft 84 within a predetermined angle range. With such a configuration, the gap g can be formed by a simple cam mechanism.

[0066] Next, still another embodiment will be described.

[0067] 8 is a schematic cross-sectional view showing an inlet guide vane 100 according to the third embodiment. The inlet guide vane 100 according to the third embodiment differs from the inlet guide vane 100 according to the first and second embodiments in the configuration of the vane 8B. The other configurations of the third embodiment may be the same as those of the first and second embodiments.

[0068] In this embodiment, the downstream wing piece 82 is fixed to the first shaft 83 such that a gap g is formed between the upstream wing piece 81 and the downstream wing piece 82. Thus, like the upstream wing piece 81, the downstream wing piece 82 rotates integrally with the first shaft 83 and does not rotate relative to the first shaft 83. Furthermore, the gap g is formed between the upstream wing piece 81 and the downstream wing piece 82 regardless of the rotational position of the vane 8B. Specifically, the downstream wing piece 82 is fixed to the support plate 83a. For example, the downstream wing piece 82 may include a protrusion penetrating the support plate 83a, and may be fixed by a part such as a nut or a rivet.

[0069] The vane 8 includes a lid 88. The lid 88 is rotatably supported on one of the upstream winglet 81 and the downstream winglet 82. In this embodiment, the lid 88 is supported on the upstream winglet 81. For example, the lid 88 may be attached to the upstream winglet 81 by a hinge. The lid 88 is positioned to cover both the upstream winglet 81 and the downstream winglet 82.

[0070] Fig. 9 shows the vane 8B in the fully closed state S1, the fully open state S2 and the over-open state S3 as viewed from the direction of the arrow B in Fig. 8. In Fig. 9, the vane 8B is viewed from the radially inner side, similar to Fig. 3.

[0071] The lid 88 is configured to open the gap g when the vane 8B tilts beyond the limit L, as shown in the over-open state S3, and to close the gap g when the vane 8B is positioned between the fully closed state S1 and the limit L, as shown in the fully closed state S1 and the fully open state S2.

[0072] Specifically, the lid 88 is disposed on the surface of the upstream wing piece 81 and the downstream wing piece 82 that faces the upstream side in the fully closed state S1. In this embodiment, the contact surface between the upstream wing piece 81 and the downstream wing piece 82 is inclined in the blade thickness direction opposite to that in the first embodiment so that the gap g can easily receive the fluid in the over-open state S3.

[0073] When the vane 8B is positioned between the fully closed state S1 and the fully open state S2, the lid 88 is pressed against the surfaces of the upstream wing piece 81 and the downstream wing piece 82 by the flow of fluid. When the vane 8B is positioned in the over-open state S3, the fluid enters the gap g from the side opposite the lid 88. The lid 88 is configured to be opened by the fluid flowing through the gap g when the angle α exceeds the angle of the limit L. For example, the angle α at which the lid 88 opens may be adjusted by adjusting the weight of the lid 88. The angle α at which the lid 88 opens may also be adjusted according to other factors.

[0074] The inlet guide vane 100 as described above achieves substantially the same effects as the inlet guide vane 100 according to the first embodiment. In particular, in the third embodiment, each of the vanes 8B includes a lid 88 that is rotatably supported on one of the upstream wing piece 81 and the downstream wing piece 82, and that opens the gap g when the vane 8B is tilted beyond the limit L, and closes the gap g when the vane 8B is located between the fully closed state S1 and the limit L. With this configuration, the gap g can be opened and closed by the simple lid 88.

[0075] Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to the above-described embodiments. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure.

[0076] For example, in the first embodiment, the second shaft 84 and the downstream winglet 82 are rotated by a gear mechanism. In other embodiments, for example, the second shaft 84 and the downstream winglet 82 may be rotated by other mechanical structures, such as a linkage, or electrical components, such as a motor.

[0077] Also, in the second embodiment, the second shaft 84 and the downstream winglet 82 are moved by a cam mechanism. In other embodiments, for example, the second shaft 84 and the downstream winglet 82 may be moved by other mechanical structures, such as a linkage mechanism, electrical components, such as a solenoid, or hydraulic components, such as a cylinder.

[0078] Also, in the first and second embodiments, the downstream winglet 82 rotates or moves relative to the upstream winglet 81. In other embodiments, the upstream winglet 81 may rotate or move relative to the downstream winglet 82. In yet other embodiments, both the upstream winglet 81 and the downstream winglet 82 may rotate or move relative to each other.

[0079] In the above embodiment, the IGV 100 is applied to a centrifugal compressor. In another embodiment, the IGV 100 may be applied to an axial compressor. [Explanation of symbols]

[0080] 8 Vane 8A Vane 8B Vane 74 Compressor housing inner wall 81 Upstream wing segment (1st wing segment, 2nd wing segment) 82 Downstream wing segment (1st wing segment, 2nd wing segment) 83 1st Shaft 83a Support plate 83b long hole 83c Elastic body 84 2nd Shaft 85 1st Gear 85a 1st tooth 86 2 Gears 86a 2nd tooth 87 Cam 88 Lid 100 Inlet Guide Vane (IGV) C1 Centrifugal Compressor C2 Centrifugal Compressor C3 Centrifugal Compressor g Gap L Limit S2 Fully open X1 First vane axis X2 Second vane axis

Claims

1. An inlet guide vane provided in an intake passage of a compressor, A plurality of vanes arranged in a circumferential direction are provided, an angle of each of the plurality of vanes is variable with respect to the mainstream; The angle can be adjusted on both sides of a fully open state in which a cross-sectional area of ​​the main flow is maximized when viewed in a direction along the main flow, each of the plurality of vanes includes a first wing and a second wing; When the angle exceeds a limit at a predetermined angle and tilts to one side from the fully open state, a gap is generated between the first wing piece and the second wing piece, If the angle does not exceed the limit, the gap closes. Inlet guide vanes.

2. The inlet guide vane of claim 1 , wherein the gap gradually increases as the vane moves from the limit toward the fully open condition.

3. The inlet guide vane of claim 2 , wherein the second airfoil is rotatable away from the first airfoil.

4. Each of the plurality of vanes is a first shaft supporting the first wing piece and rotatable about a first vane axis; a first gear disposed around the first shaft and fixed to an inner wall of a housing that accommodates the inlet guide vane, the first gear including a plurality of first teeth only in a predetermined angular range; a second shaft supporting the second winglet and rotatably supported by the first shaft about a second vane axis; a second gear disposed about and fixed to the second shaft, the second gear including a plurality of second teeth that engage the first teeth of the first gear, the first teeth and the second teeth engaging with each other, and rotating about the second vane axis when the first shaft rotates; The inlet guide vane of claim 3 , comprising:

5. The inlet guide vane of claim 2 , wherein the second winglet is movable away from the first winglet while maintaining an angle relative to the first winglet.

6. Each of the plurality of vanes is a first shaft supporting the first wing piece and rotatable about a first vane axis; a second shaft supporting the second winglet and supported by the first shaft, the second shaft being movable away from the first vane axis; a cam disposed around the first shaft and fixed to an inner wall of a housing that accommodates the inlet guide vane, the cam pressing the second shaft within a predetermined angle range; The inlet guide vane of claim 5 , comprising:

7. Each of the plurality of vanes is 2. The inlet guide vane of claim 1 including a lid rotatably supported on one of the first and second winglets, the lid opening the gap when the vane is tilted beyond the limit and closing the gap when the vane is positioned between a fully closed state and the limit.

8. The inlet guide vane according to claim 1 , wherein the first and second wing pieces are separated in a chord length direction.

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