Rotary device

Abstract

A rotary device T1 is provided with: an impeller 3; a first housing 6; a second housing 5; an annular flow path 62 positioned on an outer side in a radial direction of the impeller 3; a plurality of vanes V disposed in the annular flow path 62; and a ring plate 52 disposed between the plurality of vanes V and the second housing 5, and holding the plurality of vanes V. The plurality of vanes V are fixed to the ring plate 52, and the ring plate 52 includes a positioning surface 54a facing an inner side in the radial direction and coming into contact with the second housing 5 from the outer side in the radial direction. The rotary device T1 is also provided with an elastic body 55 disposed between the ring plate 52 and the second housing 5, and pressing the ring plate 52 and the plurality of vanes V in an axial direction. The positioning surface 54a is positioned radially inward of the elastic body 55, or is positioned at the same position in the radial direction as a radial inner end of the elastic body 55.

Description

Rotating device

[0001] This application claims the benefit of priority from Japanese Patent Application No. 2023-143955, filed on September 5, 2023, the contents of which are incorporated herein by reference.

[0002] A rotary device such as a turbine may include a plurality of vanes arranged radially outward of an impeller. The vanes may be fixed to a ring plate. For example, Patent Document 1 discloses a turbine device including a plurality of guide vanes arranged radially outward of a turbine wheel. The guide vanes are fixed to a support ring. The support ring abuts against a cylindrical centering surface facing radially inward of a turbine housing.

[0003] Japanese Patent Application Laid-Open No. 2022-161035

[0004] For example, high-temperature exhaust gas is supplied to the turbine. The heat from the exhaust gas can cause thermal deformation of the ring plate. When the ring plate is thermally deformed, a gap forms between the ring plate and the housing, which can allow exhaust gas to leak through the gap to the back of the impeller. This leads to a decrease in turbine performance.

[0005] An object of the present disclosure is to provide a rotating device that can reduce gas leakage.

[0006] A rotating device according to one aspect of the present disclosure comprises: a shaft; an impeller provided at one end of the shaft; a first housing that accommodates the impeller; a second housing that is connected to the first housing and accommodates a bearing that rotatably supports the shaft; an annular flow path formed between the first housing and the second housing and located radially outward of the impeller; a plurality of vanes arranged in the annular flow path along a circumferential direction; a ring plate that is arranged between the plurality of vanes and the second housing and holds the plurality of vanes, the plurality of vanes being fixed to the ring plate, the ring plate including a positioning surface that faces radially inward and contacts the second housing from the radially outward; and an elastic body that is arranged between the ring plate and the second housing and presses the ring plate and the plurality of vanes in the axial direction, the positioning surface being located radially inward of the elastic body or located at the same radial position as the radially inner end of the elastic body.

[0007] The rotating device may have a scroll passage formed in the first housing and located radially outside the annular passage, and the radially outer edge of one of the plurality of vanes may be located on a line connecting a tongue of the scroll passage and the axis of the impeller when viewed in the axial direction.

[0008] The ring plate may include one of a protrusion and a groove that engages with the protrusion, and one of the first housing and the second housing may include the other of the protrusion and the groove.

[0009] The elastic body may contact the ring plate at a position radially outward of radially inner edges of the plurality of vanes.

[0010] According to the present disclosure, gas leakage can be reduced.

[0011] Fig. 1 is a schematic cross-sectional view of a turbocharger including a turbine according to a first embodiment. Fig. 2 is a schematic enlarged cross-sectional view of part A in Fig. 1. Fig. 3 is a schematic cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a schematic enlarged cross-sectional view of a turbocharger including a turbine according to a second embodiment.

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Specific dimensions, materials, numerical values, etc. shown in the embodiments are merely examples for ease of 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 designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0013] 1 is a schematic cross-sectional view of a turbocharger 100 including a turbine T1 according to a first embodiment. The turbine T1 according to this embodiment is applied to the turbocharger 100. In other embodiments, the turbine T1 may be applied to equipment other than the turbocharger 100, or may be a standalone unit. The turbocharger 100 includes a housing 1, a shaft 2, a turbine impeller 3, and a compressor impeller 4.

[0014] As will be described later, the turbine impeller 3 and the compressor impeller 4 rotate integrally with the shaft 2. Therefore, the axis of the turbine impeller 3 and the axis of the compressor impeller 4 are the same as the axis of the shaft 2. For this reason, in the present 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. Furthermore, in the present disclosure, the axis of the shaft 2, the turbine impeller 3, and the compressor impeller 4 may be simply referred to as the "axis" unless otherwise specified.

[0015] The housing 1 includes a bearing housing (second housing) 5, a turbine housing (first housing) 6, and a compressor housing 7. One end of the bearing housing 5 is axially connected to the turbine housing 6 by a fastener such as a G coupling. The other end of the bearing housing 5 is axially connected to the compressor housing 7 by a fastener such as a bolt.

[0016] The bearing housing 5 includes a bearing hole 51. The bearing hole 51 extends in the axial direction within the bearing housing 5. The bearing hole 51 accommodates a bearing B. The bearing B rotatably supports the shaft 2. In this embodiment, a pair of rolling bearings is used as the bearing B. In other embodiments, other radial bearings such as full-floating bearings or semi-floating bearings may be used as the bearing B.

[0017] A turbine impeller 3 is provided at a first end of the shaft 2 in the axial direction. The turbine impeller 3 rotates integrally with the shaft 2. A turbine housing 6 rotatably accommodates the turbine impeller 3. A compressor impeller 4 is provided at a second end of the shaft 2 opposite the first end in the axial direction. The compressor impeller 4 rotates integrally with the shaft 2. A compressor housing 7 rotatably accommodates the compressor impeller 4.

[0018] The compressor housing 7 includes an air intake port 71 at an end opposite to the bearing housing 5 in the axial direction. The air intake port 71 is connected to an air cleaner (not shown).

[0019] The bearing housing 5 and the compressor housing 7 include a diffuser passage 72 therebetween. The diffuser passage 72 has an annular shape. The diffuser passage 72 is located radially outward from the compressor impeller 4. The diffuser passage 72 is in fluid communication with the intake port 71 via the compressor impeller 4.

[0020] The compressor housing 7 includes a compressor scroll passage 73. The compressor scroll passage 73 is located radially outward of the diffuser passage 72. The compressor scroll passage 73 communicates with the diffuser passage 72. The compressor scroll passage 73 also fluidly communicates with an intake port of the engine (not shown).

[0021] When the compressor impeller 4 rotates, air is drawn into the compressor housing 7 through the intake port 71. The air is accelerated and pressurized by centrifugal force while passing through the compressor impeller 4. The air is further pressurized when passing through 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 the intake port of the engine. In the turbocharger 100, a portion including the compressor impeller 4 and the compressor housing 7 functions as a centrifugal compressor C.

[0022] 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).

[0023] The bearing housing 5 and the turbine housing 6 include a connecting passage (annular passage) 62 therebetween. The connecting passage 62 has an annular shape. The connecting passage 62 is located radially outward from the turbine impeller 3. The connecting passage 62 is fluidly connected to the discharge port 61 via the turbine impeller 3. A plurality of vanes V are arranged in the connecting passage 62. The plurality of vanes V are arranged along the circumferential direction in a region radially outward from the turbine impeller 3. The vanes V will be described in detail later.

[0024] The turbine housing 6 includes a turbine scroll passage 63. The turbine scroll passage 63 is located radially outward of the connecting passage 62. The turbine scroll passage 63 communicates with the connecting passage 62. The turbine scroll passage 63 also fluidly communicates with a gas inlet (not shown). The gas inlet receives exhaust gas discharged from an exhaust manifold (not shown) of the engine.

[0025] Exhaust gas is guided from the gas inlet to the turbine scroll passage 63, and further guided to the discharge port 61 via the connecting passage 62 and the turbine impeller 3. The exhaust gas rotates the turbine impeller 3 while passing through it. 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 is compressed as described above. The compressed air is then guided to the intake port of the engine. In the turbocharger 100, a portion including the turbine impeller 3 and the turbine housing 6 functions as the turbine T1.

[0026] Next, the vane V will be described.

[0027] Figure 2 is a schematic enlarged cross-sectional view of part A in Figure 1. The turbine T1 includes a ring plate 52. In this embodiment, the ring plate 52 further includes a first ring plate 53 and a second ring plate 54. The turbine T1 also includes an elastic body 55. The bearing housing 5 includes an accommodation groove 56 for accommodating the first ring plate 53, the second ring plate 54, and the elastic body 55. The accommodation groove 56 has a generally annular shape.

[0028] In this embodiment, the plurality of vanes V are held by the first ring plate 53. The first ring plate 53 is disposed between the plurality of vanes V and the bearing housing 5 in the axial direction. That is, the first ring plate 53 is disposed between the connecting passage 62 and the bearing housing 5 in the axial direction. The first ring plate 53 defines a portion of the connecting passage 62. The first ring plate 53 has an annular shape around the axis.

[0029] The vanes V are fixed to the end surface 53 a of the first ring plate 53. The end surface 53 a faces the connecting flow passage 62 in the axial direction. That is, the vanes V do not move or rotate relative to the first ring plate 53. In the present disclosure, the vanes V may also be referred to as fixed vanes. For example, the vanes V may be formed integrally with the first ring plate 53. Alternatively, the vanes V may be formed separately from the first ring plate 53 and connected to the first ring plate 53 by welding, bolts, or the like.

[0030] FIG. 3 is a schematic cross-sectional view taken along line III-III in FIG. 1. FIG. 3 shows a cross-sectional view seen in the axial direction. For better understanding, FIG. 3 only shows the turbine housing 6, the first ring plate 53, and the vanes V. In this embodiment, the first ring plate 53 includes a protrusion 57. For example, the protrusion 57 protrudes radially outward from the outer peripheral surface 53b of the first ring plate 53. In this embodiment, the turbine housing 6 includes a groove 64. The protrusion 57 is inserted into the groove 64. Engagement between the protrusion 57 and the groove 64 prevents rotation of the first ring plate 53 relative to the turbine housing 6 and positions the first ring plate 53 and the plurality of vanes V in the circumferential direction. In other embodiments, the turbine housing 6 may include the protrusion, and the first ring plate 53 may include a groove that engages with the protrusion.

[0031] The turbine housing 6 includes a tongue portion 65. In the present disclosure, the term "tongue portion" refers to the circumferential end portion of a wall that radially separates the turbine scroll passage 63 and the connecting passage 62. In the present embodiment, the leading edge (radially outer edge) LE of one vane Vb of the multiple vanes V is located on a line segment LS connecting the tongue portion 65 and the axis X. In the present disclosure, the leading edge LE refers to the upstream end portion of the vane V. In the present embodiment, the remaining vanes V are evenly arranged in the circumferential direction with respect to the vane Vb. In the present disclosure, the vane Vb may also be referred to as a reference vane.

[0032] Returning to FIG. 2 , the second ring plate 54 is disposed between the first ring plate 53 and the bearing housing 5. In the present disclosure, the second ring plate 54 may also be referred to as a "heat shield plate." The second ring plate 54 has an annular shape about the axis. For example, the second ring plate 54 is configured to contact the inner circumferential surface 53 c and the end face 53 d of the first ring plate 53. The end face 53 d is located opposite the end face 53 a that holds the vane V.

[0033] The bearing housing 5 includes a surface 56a facing radially outward. In this embodiment, the surface 56a has a cylindrical shape. The surface 56a defines a receiving groove 56 in the radial direction.

[0034] The inner circumferential surface 54a of the second ring plate 54 contacts the surface 56a of the bearing housing 5. Specifically, the inner circumferential surface 54a faces radially inward and contacts the surface 56a from the radially outward side. For example, the inner circumferential surface 54a has a cylindrical shape. For example, the surface 56a is press-fitted into the inner circumferential surface 54a. In this manner, the multiple vanes V, the first ring plate 53, and the second ring plate 54 are positioned in the radial direction. In the present disclosure, the inner circumferential surface 54a of the second ring plate 54 may also be referred to as a "positioning surface."

[0035] The elastic body 55 is disposed between the second ring plate 54 and the bearing housing 5 in the axial direction. The elastic body 55 pushes the ring plate 52 and the plurality of vanes V toward the turbine housing 6 in the axial direction. In this embodiment, for example, the elastic body 55 is a disc spring. In other embodiments, the elastic body 55 may be another elastic body such as a plurality of coil springs.

[0036] The elastic body 55 contacts the ring plate 52 at a position radially outward of the trailing edges (radially inner edges) TE of the multiple vanes V. Specifically, in this embodiment, the outer peripheral edge of the elastic body 55 contacts the second ring plate 54. Therefore, the diameter of the outer peripheral edge of the elastic body 55 is larger than the diameter of a circle that passes through the trailing edges TE of the multiple vanes V. In this embodiment, the inner peripheral edge of the elastic body 55 contacts the bearing housing 5.

[0037] The elastic body 55 is located radially outward from the contact position between the second ring plate 54 and the bearing housing 5, i.e., from the inner circumferential surface 54a of the second ring plate 54 and the surface 56a of the bearing housing 5. In other words, the inner circumferential surface (positioning surface) 54a of the second ring plate 54 is located radially inward from the elastic body 55.

[0038] As described above, exhaust gas from the engine flows through the connecting passage 62. The ring plate 52 is exposed to the exhaust gas. If the exhaust gas reaches a high temperature, the ring plate 52 may be thermally deformed. The thermal deformation of the radially outer portion is greater than the thermal deformation of the radially inner portion. Therefore, if the ring plate 52 is positioned at the radially outer portion, a gap is likely to form between the ring plate 52 and the bearing housing 5 or the turbine housing 6. In this case, exhaust gas is likely to leak from the gap into the accommodation groove 56 and further onto the back surface of the turbine impeller 3. This leads to a decrease in performance of the turbine T1.

[0039] In contrast, in the turbine T1 according to this embodiment, the ring plate 52 is positioned at its radially inner portion, i.e., by the inner circumferential surface 54a of the second ring plate 54. Therefore, a gap is less likely to form between the ring plate 52 and the bearing housing 5. In this case, it is possible to reduce exhaust gas leakage.

[0040] As described above, the turbine T1 according to this embodiment comprises: the shaft 2; the turbine impeller 3 provided at one end of the shaft 2; the turbine housing 6 accommodating the turbine impeller 3; the bearing housing 5 connected to the turbine housing 6 and accommodating the bearing B that rotatably supports the shaft 2; an annular connecting flow passage 62 formed between the turbine housing 6 and the bearing housing 5 and located radially outside the turbine impeller 3; a plurality of vanes V arranged in the connecting flow passage 62 along the circumferential direction; a ring plate 52 arranged between the plurality of vanes V and the bearing housing 5 and holding the plurality of vanes V, the ring plate 52 facing radially inward and including a positioning surface 54 a that contacts the bearing housing 5 from the radially outer side; and an elastic body 55 arranged between the ring plate 52 and the bearing housing 5 and pressing the ring plate 52 and the plurality of vanes V in the axial direction, the positioning surface 54 a being located radially inside the elastic body 55. As described above, with this configuration, the ring plate 52 is positioned by the positioning surface 54a, which is radially inward of the elastic body 55. Therefore, a gap is less likely to form between the ring plate 52 and the bearing housing 5. As a result, exhaust gas leakage can be reduced.

[0041] The turbine T1 also has a turbine scroll passage 63 formed in the turbine housing 6 and located radially outside the connecting passage 62, and the leading edge LE of one vane Vb of the multiple vanes V is located on a line LS connecting a tongue portion 65 of the turbine scroll passage 63 and the axis X of the turbine impeller 3 when viewed in the axial direction.

[0042] Furthermore, in the turbine T1, the ring plate 52 includes a protrusion 57, and the turbine housing 6 includes a groove 64 that engages with the protrusion 57. With this simple configuration, it is possible to prevent the ring plate 52 from rotating.

[0043] In the turbine T1, the elastic body 55 comes into contact with the ring plate 52 at a position radially outward of the trailing edges TE of the plurality of vanes V. With this configuration, the vanes V can be firmly pressed against the turbine housing 6.

[0044] Next, other embodiments will be described.

[0045] 4 is a schematic enlarged cross-sectional view of a turbocharger 100 including a turbine T2 according to a second embodiment. The turbine T2 differs from the turbine T1 according to the first embodiment in that the ring plate 52 includes only a first ring plate 53 and does not include a second ring plate 54. The accommodation groove 56 is also reduced in size in the radial and axial directions. In particular, the surface 56a of the bearing housing 5 is moved radially outward. Other configurations of the turbine T2 may be the same as those of the turbine T1.

[0046] In this embodiment, the inner circumferential surface 53c of the first ring plate 53 is used to position the multiple vanes V and the first ring plate 53. Specifically, in this embodiment, the inner circumferential surface 53c of the first ring plate 53 contacts the surface 56a of the bearing housing 5. The inner circumferential surface 53c faces radially inward and contacts the surface 56a from the radially outward side. For example, the inner circumferential surface 53c has a cylindrical shape. For example, the surface 56a is press-fitted into the inner circumferential surface 53c. In this manner, the multiple vanes V and the first ring plate 53 are positioned in the radial direction. In the present disclosure, the inner circumferential surface 53c of the first ring plate 53 may also be referred to as a "positioning surface."

[0047] In this embodiment, the outer peripheral edge of the elastic body 55 contacts the first ring plate 53. In this embodiment, the inner peripheral edge of the elastic body 55 contacts the bearing housing 5. In this embodiment, the inner peripheral edge of the elastic body 55 is spaced apart from the surface 56 a of the bearing housing 5.

[0048] The turbine T2 configured as described above has the same effects as the turbine T1 according to the first embodiment.

[0049] 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 conceive of various modifications or alterations within the scope of the claims, and it is understood that such modifications also fall within the technical scope of the present disclosure.

[0050] For example, in the above embodiment, the present invention is applied to the vanes (nozzle vanes) V arranged in the connecting flow passage 62 of the turbine T1. In other embodiments, the present invention may be applied to diffuser vanes (not shown) arranged in the diffuser flow passage 72 of the centrifugal compressor C.

[0051] Also, for example, in the above embodiment, the protrusions 57 protrude radially outward from the outer peripheral surface 53b of the first ring plate 53. In other embodiments, the protrusions 57 may protrude radially inward from the inner peripheral surface of the first ring plate 53 or the second ring plate 54, and the grooves 64 may be provided at corresponding positions on the bearing housing 5.

[0052] Also, for example, in the above embodiment, the positioning surfaces 54a and 53c are located radially inward of the elastic body 55. For example, in the second embodiment of FIG. 4, the inner peripheral edge of the elastic body 55 may be in contact with the surface 56a of the bearing housing 5, and the positioning surface 53c may be located at the same position as the inner peripheral edge of the elastic body 55 in the radial direction.

[0053] 2 Shaft 3 Turbine impeller 5 Bearing housing (second housing) 6 Turbine housing (first housing) 52 Ring plate 53c Inner peripheral surface (positioning surface) 54a Inner peripheral surface (positioning surface) 55 Elastic body 57 Protrusion 62 Connecting flow passage (annular flow passage) 63 Turbine scroll flow passage 64 Groove 65 Tongue portion B Bearing LE Leading edge (radially outer edge) LS Line segment T1 Turbine (rotating device) T2 Turbine (rotating device) TE Trailing edge (radially inner edge) V Vane X Axis

Claims

1. A rotating device comprising: a shaft; an impeller provided at one end of the shaft; a first housing accommodating the impeller; a second housing connected to the first housing and accommodating a bearing for rotatably supporting the shaft; an annular flow passage formed between the first housing and the second housing and located radially outward of the impeller; a plurality of vanes arranged in the annular flow passage along a circumferential direction; a ring plate arranged between the plurality of vanes and the second housing and holding the plurality of vanes, the plurality of vanes being fixed to the ring plate, the ring plate including a positioning surface facing radially inward and contacting the second housing from the radially outward; and an elastic body arranged between the ring plate and the second housing and pressing the ring plate and the plurality of vanes in the axial direction, the positioning surface being located radially inward of the elastic body or located at the same position radially as the radially inner end of the elastic body.

2. A rotating device as described in claim 1, comprising a scroll passage formed in the first housing and positioned radially outside the annular passage, and wherein the radially outer edge of one of the plurality of vanes is positioned on a line segment connecting a tongue of the scroll passage and the axis of the impeller when viewed in the axial direction.

3. A rotating device as set forth in claim 1 or 2, wherein the ring plate includes one of a protrusion and a groove that engages with the protrusion, and one of the first housing and the second housing includes the other of the protrusion and the groove.

4. A rotating device according to claim 1 or 2, wherein the elastic body contacts the ring plate at a position radially outward of radially inner edges of the plurality of vanes.

5. The rotating device according to claim 3, wherein the elastic body contacts the ring plate at a position radially outward of the radially inner edges of the vanes.

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