WO2020050051A1 - Turbine and supercharger - Google Patents

Abstract

This turbine is provided with: a turbine scroll flow passage formed in a turbine housing 4; a turbine impeller 9 disposed radially inward of the turbine scroll flow passage and having a plurality of blades 9b; and a tongue section 20 located at a downstream section 16b1 in the turbine scroll flow passage and having at the tip thereof a facing section 20a softer than the blades 9b.

Description

Turbine and supercharger

The present disclosure relates to a turbine and a supercharger. This application claims the benefit of priority based on Japanese Patent Application No. 2018-165447 filed on Sep. 4, 2018, the contents of which are incorporated herein by reference.

タ ー ビ ン The turbocharger is provided with a turbine. The turbine is provided with a turbine impeller. A turbine scroll passage is formed radially outside the turbine impeller. For example, as described in Patent Document 1, an upstream portion and a downstream portion of a turbine scroll flow path are separated by a tongue. The tongue is radially opposed to the turbine impeller.

JP-A-8-61005

排 気 If the exhaust gas leaks from the upstream part to the downstream part of the turbine scroll flow path through the gap between the tongue and the turbine impeller, the turbine performance deteriorates. Therefore, there is a demand for the development of a technique for suppressing the amount of exhaust gas leakage and improving turbine performance.

目的 An object of the present disclosure is to provide a turbine and a supercharger capable of improving turbine performance.

In order to solve the above-described problems, a turbine according to an embodiment of the present disclosure includes a turbine scroll passage formed in a turbine housing, and a turbine impeller disposed radially inside the turbine scroll passage and having a plurality of blades. And a tongue, which is located downstream of the turbine scroll flow path and has an opposing portion that is softer than the blades and is provided at the tip.

The turbine scroll passage may include a plurality of turbine scroll passages, and the tongues may be formed in the same number as the turbine scroll passages.

隙間 When the blade is located radially inward with respect to the opposing portion, a gap may be formed between the opposing portion and the blade.

The facing portion may be made of an abradable material.

耐熱 The heat resistant temperature of the facing portion may be 300 ° C. or higher.

Of the leading edges of the blade, the other end than the one end in the rotation axis direction is located radially inward, and at least a part of the opposing portion is radially opposed to the leading edge, and is closer than the one end of the leading edge. It may be located radially inward.

The tongue may include a base provided on the turbine housing, and the opposing portion may be provided on the base and protrude at least one of a front side in the rotational direction of the turbine impeller and a radially inner side.

た め In order to solve the above problem, a supercharger according to an embodiment of the present disclosure includes the above turbine.

According to the present disclosure, it is possible to improve turbine performance.

FIG. 1 is a schematic sectional view of the supercharger. FIG. 2 is a sectional view of the turbine housing. FIG. 3 is an enlarged view of the vicinity of the tongue of FIG. FIG. 4 is a diagram for explaining a modified example.

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, and the like shown in the embodiments are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be omitted. Elements not directly related to the present disclosure are not shown.

FIG. 1 is a schematic sectional view of the supercharger C. The direction of arrow L shown in FIG. 1 will be described as the left side of the supercharger C. 1 will be described as the right side of the supercharger C. As shown in FIG. 1, the supercharger C includes a supercharger main body 1. The supercharger main body 1 includes a bearing housing 2. A turbine housing 4 is connected to the left side of the bearing housing 2 by a fastening bolt 3. A compressor housing 6 is connected to the right side of the bearing housing 2 by a fastening bolt 5.

軸 受 A bearing hole 2a is formed in the bearing housing 2. The bearing hole 2a penetrates the turbocharger C in the left-right direction. A bearing 7 is provided in the bearing hole 2a. FIG. 1 shows a full floating bearing as an example of the bearing 7. However, the bearing 7 may be another radial bearing such as a semi-floating bearing or a rolling bearing. The shaft 8 is rotatably supported by the bearing 7. A turbine impeller 9 is provided at the left end of the shaft 8. A turbine impeller 9 is rotatably housed in a housing space S formed in the turbine housing 4.

The turbine impeller 9 has a hub 9a and a blade 9b. The hub 9a is provided on the shaft 8. The outer diameter of the outer peripheral surface 9a1 of the hub 9a is one end side (the left side in FIG. 1; the side opposite to the bearing 7, the shaft 8, and the compressor impeller 10) of the turbine impeller 9 in the rotation axis direction (hereinafter, simply referred to as the rotation axis direction). It becomes smaller as going toward. A blade 9b is provided on an outer peripheral surface 9a1 of the hub 9a. A plurality of blades 9b are provided apart from each other in the circumferential direction of the hub 9a.

A leading edge 9b1 is formed at the upstream end of the blade 9b in the flow direction of the exhaust gas. Among the leading edge 9b1, one end 9b2 and the other end 9b3 in the rotation axis direction have substantially the same radial position of the turbine impeller 9. The turbine impeller 9 is constituted by a so-called radial impeller.

コ ン プ レ ッ サ A compressor impeller 10 is provided at the right end of the shaft 8. A compressor impeller 10 is rotatably accommodated in the compressor housing 6. An intake port 11 is formed in the compressor housing 6. The intake port 11 opens to the right of the turbocharger C. The intake port 11 is connected to an air cleaner (not shown). In a state where the bearing housing 2 and the compressor housing 6 are connected by the fastening bolts 5, the diffuser flow path 12 is formed. The diffuser channel 12 pressurizes air. The diffuser channel 12 is formed in an annular shape from the radial inside to the outside of the shaft 8. The diffuser flow path 12 communicates with the intake port 11 via the compressor impeller 10 on the radially inner side.

コ ン プ レ ッ サ A compressor scroll passage 13 is formed inside the compressor housing 6. The compressor scroll channel 13 is annular. The compressor scroll channel 13 is located, for example, radially outward of the shaft 8 from the diffuser channel 12. The compressor scroll passage 13 communicates with an intake port of an engine (not shown). The compressor scroll channel 13 also communicates with the diffuser channel 12. When the compressor impeller 10 rotates, air is drawn into the compressor housing 6 from the intake port 11. The intake air is accelerated by the action of centrifugal force in the process of flowing between the blades of the compressor impeller 10. The speed-up air is pressurized in the diffuser channel 12 and the compressor scroll channel 13. The pressurized air is led to the intake port of the engine.

吐出 A discharge port 14 is formed in the turbine housing 4. The discharge port 14 opens to the left of the supercharger C. The discharge port 14 is connected to an exhaust gas purification device (not shown). The discharge port 14 communicates with the storage space S. The turbine housing 4 is provided with a flow path 15 and a turbine scroll flow path 16. The turbine scroll flow path 16 is located radially outward of the turbine impeller 9 from the accommodation space S (turbine impeller 9). The flow path 15 is located between the storage space S and the turbine scroll flow path 16. The flow path 15 communicates the accommodation space S and the turbine scroll flow path 16.

The turbine scroll flow path 16 is configured to include two turbine scroll flow paths 16a and 16b. The shape of each of the turbine scroll passage portions 16a and 16b will be described later in detail.

The turbine scroll passage 16 communicates with the gas inlet 17 (see FIG. 2). Exhaust gas discharged from an exhaust manifold (not shown) of the engine is guided to the gas inlet 17. The turbine scroll flow path 16 also communicates with the flow path 15. The exhaust gas guided from the gas inlet 17 to the turbine scroll flow path 16 is guided to the discharge port 14 via the flow path 15 and the space between the blades of the turbine impeller 9. The exhaust gas guided to the discharge port 14 rotates the turbine impeller 9 during the flow of the exhaust gas.

Thus, the turbocharger C includes the turbine T. The turbine T includes a turbine housing 4, a turbine impeller 9, and a turbine scroll flow path 16. The torque of the turbine impeller 9 is transmitted to the compressor impeller 10 via the shaft 8. The air pressurized by the rotational force of the compressor impeller 10 is guided to the intake port of the engine.

FIG. 2 is a sectional view of the turbine housing 4. FIG. 2 shows a view in which the turbine housing 4 is cut along a plane perpendicular to the axial direction of the shaft 8 and passing through the flow path 15. Further, in FIG. 2, with respect to the turbine impeller 9, only the outer periphery of the hub 9a is indicated by a circle.

ガ ス A gas inlet 17 is formed in the turbine housing 4. The gas inlet 17 includes two gas inlets 17a and 17b. The gas inlets 17a and 17b open to the outside of the turbine housing 4.

導入 An introduction path 18a is formed between the gas inlet 17a and the turbine scroll passage 16a so as to extend substantially linearly. The gas inlet 17a communicates with the turbine scroll passage 16a via the introduction passage 18a. Similarly, an introduction path 18b extending substantially linearly is formed between the gas inlet 17b and the turbine scroll passage 16b. The gas inlet 17b communicates with the turbine scroll passage 16b via the introduction passage 18b.

The turbine scroll passage 16a, the gas inlet 17a, and the introduction passage 18a are separated from the turbine scroll passage 16b, the gas inlet 17b, and the introduction passage 18b by a wall 19.

The turbine scroll passage 16a is located radially inward of the shaft 8 from the turbine scroll passage 16b. The turbine scroll passage portion 16a extends radially outward of the turbine impeller 9 over substantially a half circumference. The turbine scroll passage portion 16a radially opposes the turbine impeller 9 over substantially a half circumference. The radial width of the turbine scroll passage portion 16a decreases as the distance from the gas inlet portion 17a increases.

The turbine scroll flow path portion 16b extends substantially radially outward of the turbine impeller 9 over the entire circumference. In the turbine scroll passage section 16b, the turbine scroll passage section 16a is interposed between the turbine impeller 9 and approximately half the circumference of the turbine impeller 9. The turbine scroll flow path portion 16b radially opposes the turbine impeller 9 over a substantially half circumference that is the remaining portion where the turbine scroll flow path portion 16a is not interposed. The radial width of the turbine scroll passage portion 16b decreases as the distance from the gas inlet portion 17b increases.

上流 In the turbine scroll flow path portion 16a, the upstream portion 16a2 is located upstream of the downstream portion 16a1 in the exhaust gas flow direction. The upstream portion 16a2 is closer to the gas inlet 17a than the downstream portion 16a1. The upstream portion 16a2 has a larger radial width of the shaft 8 than the downstream portion 16a1. Similarly, in the turbine scroll flow path portion 16b, the upstream portion 16b2 is located upstream of the downstream portion 16b1 in the exhaust gas flow direction. The upstream portion 16b2 is closer to the gas inlet 17b than the downstream portion 16b1. The upstream portion 16b2 has a larger radial width of the shaft 8 than the downstream portion 16b1.

Further, two tongue portions 20 and 21 are formed in the turbine housing 4. The tongue portion 20 is located at a downstream portion 16b1 of the turbine scroll passage portion 16b. The tongue portion 20 separates the downstream portion 16b1 of the turbine scroll passage portion 16b from the upstream portion 16a2 of the turbine scroll passage portion 16a. Similarly, the tongue 21 protrudes to the downstream 16a1 of the turbine scroll passage 16a. The tongue portion 21 partitions a downstream portion 16a1 of the turbine scroll flow channel portion 16a and an upstream portion 16b2 of the turbine scroll flow channel portion 16b. The phase of the tongue portion 20 in the rotation direction of the turbine impeller 9 (hereinafter, simply referred to as the rotation direction) is shifted from the tongue portion 21 by approximately 180 degrees. However, the tongue 20 only needs to have a different phase (position) in the rotational direction with respect to the tongue 21, and the phase shift does not have to be approximately 180 degrees. The tongue portions 20 and 21 face the turbine impeller 9 in the radial direction.

よ う Thus, the turbine T of the turbocharger C is of a so-called double scroll flow path type having two turbine scroll flow path portions 16a and 16b.

FIG. 3 is an enlarged view of the vicinity of the tongue 20 of FIG. FIG. 3 shows an external view of the turbine impeller 9 from the direction of the rotation axis. In FIG. 3, the dashed arrows indicate the rotation direction of the turbine impeller 9. As described above, the tongue portion 20 partitions the downstream portion 16b1 of the turbine scroll passage portion 16b and the upstream portion 16a2 of the turbine scroll passage portion 16a.

対 向 At the tip of the tongue 20, an opposing portion 20a (shown by cross hatching in FIG. 3) is provided. The facing portion 20a forms a part of the tongue portion 20. The facing portion 20 a is made of a material different from that of the turbine housing 4. The facing portion 20a is made of an abradable material having a heat resistant temperature of 300 ° C. or higher. The facing portion 20a is softer than the blade 9b of the turbine impeller 9.

The opposing portion 20a is located at the innermost side of the tongue portion 20 in the radial direction of the turbine impeller 9 (the shaft 8) (hereinafter, simply referred to as the radial direction). The facing portion 20a is a portion of the tongue portion 20 that is closest to the blade 9b of the turbine impeller 9. The opposing portion 20a is formed on the tongue portion 20 at the distal end of the base portion 20b in the radial direction inside. The facing portion 20a also protrudes forward in the rotation direction with respect to the base portion 20b. The base 20b is, for example, a part of the turbine housing 4. The facing portion 20a is made of a different material from the base 20b.

側面 Of the opposed portion 20a, the side surface 20a1 on the upstream portion 16a2 side (the left side in FIG. 3) of the turbine scroll passage portion 16a protrudes radially inward toward the front in the rotational direction. The side surface 20a2 of the facing portion 20a on the downstream portion 16b1 side (right side in FIG. 3) of the turbine scroll passage portion 16b protrudes radially inward toward the front side in the rotational direction. The facing portion 20a tapers toward the tip.

The facing portion 20a has a thickness in the radial direction. The facing portion 20a has a thickness in the rotation direction. The thickness of the facing portion 20a may be larger or smaller than the thickness shown in FIG. The facing portion 20a may be, for example, a coating formed on the base 20b.

内径 The inner diameter Ra of the facing portion 20a is slightly larger than the outer diameter Rb of the blade 9b. The position of the facing portion 20a in the rotation axis direction at least partially overlaps the position of the blade 9b in the rotation axis direction. When the blade 9b is located radially inward with respect to the facing portion 20a, a slight gap is formed between the facing portion 20a and the blade 9b.

(4) When the exhaust gas leaks from the upstream portion 16a2 of the turbine scroll passage portion 16a to the downstream portion 16b1 of the turbine scroll passage portion 16b through the gap between the tongue portion 20 and the turbine impeller 9, the turbine performance deteriorates. Therefore, the tongue portion 20 is provided with the facing portion 20a.

The facing portion 20a is softer than the blade 9b. Therefore, if the blade 9b comes into contact with the facing portion 20a, the facing portion 20a is scraped. Therefore, it is possible to design the gap in the radial direction between the tongue 20 and the blade 9b smaller than in the case where the facing portion 20a is not provided. Thus, the leakage of the exhaust gas is suppressed, and the turbine performance can be improved.

(4) As the radial thickness of the facing portion 20a is increased, the allowable range of the width at which the facing portion 20a is ground increases. Therefore, it is possible to support turbine impellers 9 having various outer diameters.

FIG. 4 is a diagram for explaining a modification. FIG. 4 is a sectional view of a portion corresponding to a section taken along line IV-IV of FIG. 2 in a modification. In FIG. 4, the contour of the blade 109b is a rotation trajectory (a projection view of the rotation trajectory on a plane including the rotation axis, meridional plane shape). In the above-described embodiment, the case where the turbine impeller 9 is a radial impeller has been described. In the modified example, a case where the turbine impeller 109 is a mixed flow impeller will be described.

A leading edge 109b1 is formed on the blade 109b of the turbine impeller 109. The other end 109b3 of the leading edge 109b1 is located radially inward from the one end 109b2 in the rotation axis direction. In the turbine impeller 109, the leading edge 109b1 is inclined with respect to the rotation axis direction. Because the other end 109b3 of the leading edge 109b1 is located radially inward, the weight of the blade 109b is reduced. Therefore, the moment of inertia can be reduced.

In FIG. 4, a part of the base end side of the tongue 120 is shown in cross section. The tongue portion 120 extends from the base end side to the front side in the rotational direction (in FIG. 4, the back side in the drawing) and radially inward. An opposing portion 120a is provided at the tip of the tongue portion 120. Like the above-described facing portion 20a, the facing portion 120a is made of an abradable material having a heat-resistant temperature of 300 ° C. or higher. The facing portion 120a is softer than the blade 109b of the turbine impeller 109.

The opposing portion 120a is located most radially inward of the tongue portion 120. The facing portion 120a is formed in the tongue portion 120 at the distal end of the base portion 120b in the radial direction. The base 120b is, for example, a part of the turbine housing 4. In FIG. 4, an example of a boundary position between the facing portion 120a and the base portion 120b is indicated by a broken line.

The facing portion 120a has a thickness in the radial direction. The thickness of the facing portion 120a may be larger or smaller than the thickness shown in FIG. The facing portion 120a may be, for example, a coating formed on the base 120b. Also, as the radial thickness of the facing portion 120a is increased, the allowable range of the width of the facing portion 120a to be ground is increased. When the blade 109b is located radially inward of the facing portion 120a, a slight gap is formed between the facing portion 120a and the blade 109b.

対 向 The opposed portion 120a and the base portion 120b of the tongue portion 120 project radially inward from one end 109b2 of the leading edge 109b1. However, the base portion 120b may not project radially inward than the one end 109b2 of the leading edge 109b1, and only the facing portion 120a may project radially inward from the one end 109b2 of the leading edge 109b1.

In the modified example, similarly to the above-described embodiment, the radial gap between the tongue portion 120 and the blade 109b can be designed to be smaller than when the opposing portion 120a is not provided. As a result, leakage of exhaust gas is suppressed, and turbine performance can be improved.

た め Since the turbine impeller 109 is a mixed flow impeller, the gap between the turbine impeller 109 and the tongue 120 is increased because the other end 109b3 of the leading edge 109b1 is radially inward. The facing portion 120a projects radially inward from one end 109b2 of the leading edge 109b1. Therefore, leakage of exhaust gas is suppressed, and turbine performance can be improved.

で は In the above-described embodiments and modified examples, the tongue portions 20 and 120 have been described. However, the tongue portion 21 has the same configuration as the tongue portions 20 and 120. However, only one of the tongues 20, 21, and 120 may have the configuration of the above-described embodiment and the modification.

Although an embodiment of the present disclosure has been described with reference to the accompanying drawings, it is needless to say that the present disclosure is not limited to the embodiment. It will be apparent to those skilled in the art that various changes or modifications can be made within the scope of the claims, and those modifications naturally belong to the technical scope of the present disclosure. You.

For example, in the above-described embodiment and modified examples, the case where the turbine T is incorporated in the supercharger C has been described. However, the turbine T may be incorporated in a device other than the turbocharger C, or may be a single unit.

In the embodiment and the modification described above, the turbine scroll flow path 16 is configured to include the two turbine scroll flow paths 16a and 16b. The case where the number of the tongue portions 20, 21, 120 having different rotational positions (phases) from each other is the same as the number of the turbine scroll passage portions 16a, 16b is two. However, the number of the turbine scroll flow paths 16a, 16b and the tongues 20, 21, 120 having different positions (phases) in the rotational direction may be three or more. The turbine scroll flow path 16 may be a single scroll flow path (it is not necessary to include the plurality of turbine scroll flow path parts 16a and 16b). However, when the turbine scroll flow path 16 includes a plurality of turbine scroll flow paths 16a, 16b, the pressure difference between the turbine scroll flow paths 16a, 16b partitioned by the tongues 20, 21, 120 is better. Becomes larger. Therefore, the effect of suppressing the amount of exhaust gas leakage is great.

In the above-described embodiment and modified examples, when the blades 9b and 109b are positioned radially inward with respect to the opposing portions 20a and 120a, a gap is formed between the opposing portions 20a and 120a and the blades 9b and 109b. Has been described. In this case, it is possible to suppress the leakage of the exhaust gas while suppressing the contact between the opposing portions 20a and 120a and the blades 9b and 109b. However, when the blades 9b and 109b are located radially inward of the facing portions 20a and 120a, a gap may not be formed between the facing portions 20a and 120a and the blades 9b and 109b.

で は In the above-described embodiment and modified examples, the case where the opposing portions 20a and 120a are made of an abradable material has been described. In this case, even if the opposing portions 20a and 120a come into contact with the blades 9b and 109b, the influence on the blades 9b and 109b can be suppressed. However, the facing portions 20a and 120a may not be made of an abradable material as long as they are softer than the blades 9b and 109b.

In the above-described embodiment and modified examples, the case where the heat-resistant temperature of the facing portions 20a and 120a is 300 ° C. or more has been described. In this case, deterioration of the facing portions 20a and 120a due to heat is suppressed in a temperature range used on the turbine side. However, depending on the temperature range used on the turbine side, the heat resistant temperature of the facing portions 20a and 120a may not be 300 ° C. or more.

In the embodiment and the modification described above, the facing portions 20a and 120a protrude from the base portions 20b and 120b both on the rotation direction front side of the turbine impellers 9 and 109 and on the radial inside. However, the facing portions 20a and 120a may protrude at least one of the front side in the rotational direction of the turbine impellers 9 and 109 and the radially inner side.

The present disclosure can be used for turbines and superchargers.

4: Turbine housing 9: Turbine impeller 9b: Blade 9b1: Leading edge 9b2: One end 9b3: Other end 15: Flow path 16: Turbine scroll flow path 16a: Turbine scroll flow path section 16a1: Downstream section 16b: Turbine scroll flow path section 16b1: Downstream portion 20: Tongue portion 20a: Opposing portion 21: Tongue portion 109: Turbine impeller 109b: Blade 109b1: Leading edge 109b2: One end 109b3: Other end 120: Tongue portion 120a: Opposing portion C: Turbocharger T: Turbine

Claims (8)

A turbine scroll passage formed in the turbine housing;
A turbine impeller arranged radially inward of the turbine scroll flow path and having a plurality of blades;
A tongue positioned at a downstream portion of the turbine scroll flow path and having an opposing portion softer than the blade provided at a tip thereof;
Turbine provided with. The turbine according to claim 1, wherein the turbine scroll passage includes a plurality of turbine scroll passages, and the tongues are formed in the same number as the turbine scroll passages. 3. The turbine according to claim 1, wherein a gap is formed between the opposing portion and the blade when the blade is positioned radially inward with respect to the opposing portion. 4. The turbine according to any one of claims 1 to 3, wherein the facing portion is made of an abradable material. The turbine according to any one of claims 1 to 4, wherein the heat-resistant temperature of the facing portion is 300C or higher. Of the leading edge of the blade, the other end than the one end in the rotation axis direction is located radially inward,
The turbine according to any one of claims 1 to 5, wherein at least a part of the facing portion is radially opposed to the leading edge and located radially inward of one end of the leading edge. The tongue includes a base provided on the turbine housing,
The turbine according to any one of claims 1 to 6, wherein the opposing portion is provided on the base portion and protrudes at least one of a rotation direction front side and a radially inner side of the turbine impeller. A supercharger comprising the turbine according to any one of claims 1 to 7.

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