JP2002180841A - Turbocompressor and turbocharger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the compression efficiency of a turbocompressor. SOLUTION: This turbocompressor 3 is provided with a bearing housing 7 rotatably receiving a shaft 8 for mounting an impeller 9 in a diffuser D, a sealing plate 11 facing to the bearing housing 7 in the diffuser D and fixed by a fastening screw 21 adjacently to the impeller 9 in the periphery of the shaft 8, and a compressor housing 6 fixed by facing to the sealing plate 11 for housing the impeller 9 in the diffuser D. A spot facing hole 20 for supporting the fastening screw 21 is formed in the sealing plate 11 in the periphery of the shaft 8. The open end part of the spot facing hole 20 is closed by a passage wall part constituting part of a pressure conversion passage 18 continuing from the impeller 9 in the diffuser D. The passage wall part is a filler 24 embedded in the spot facing hole 20. Additionally, the compressor is provided with a cover having a lid body part overlaid on the open end part of the spot facing hole 20 and formed as a passage wall part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbocharger (exhaust turbine supercharging machine) for driving a compressor by an exhaust turbine driven by exhaust gas energy and supplying compressed intake air to an engine. Regarding the turbo compressor used as the compressor,
The present invention relates to a structure in which a seal plate is connected to a bearing housing that receives a shaft on which an impeller is mounted by a diffuser. This turbo compressor is generally classified as a turbo-type centrifugal compressor among high-pressure air machines, but also includes a turbo-type centrifugal blower among low-pressure air machines.

[0002]

2. Description of the Related Art Generally, in this type of turbocharger, a bearing housing is provided between a turbine housing of an exhaust turbine and a compressor housing of a turbocompressor. The impeller and the impeller of this exhaust turbine are linked.
A bearing mechanism rotatably receiving the shaft is accommodated in the bearing housing. A seal plate is interposed at the boundary between the bearing housing and the compressor housing. In this seal plate, a plurality of counterbore holes are formed on the outer periphery of the shaft. A fastening screw is inserted into each of the counterbore holes from the compressor housing side, and the fastening screw is screwed to the bearing housing.

Conventionally, since the exhaust turbine is generally large, the outer diameter of the impeller of the turbocompressor is also large, and each counterbore is hidden behind the impeller and is exposed to a pressure conversion passage continuous from the impeller by the diffuser. Was few.

[0004]

However, at present, with the downsizing of the engine, the exhaust turbine and the turbocompressor of the turbocharger are also downsized, the outer diameter of the impeller is reduced, and the position of forming each counterbore is reconsidered. I have to do it. For example, if each counterbore is closed to the shaft and hidden behind the impeller with the downsizing of the impeller, the space for installing the bearing mechanism in the bearing housing becomes small, and the lubrication function of the bearing mechanism may be reduced. there were. Also, if each counterbore hole is provided outside the pressure conversion passage from the impeller with the diffuser and separated from the shaft, each counterbore hole can avoid this pressure conversion passage, but the bearing housing is large. And against the miniaturization of turbochargers. Therefore, it is necessary to provide each counterbore in the vicinity of the outermost peripheral edge of the impeller. However, it is often necessary to design each counterbore into this pressure conversion passage. In this case, a step is generated in the pressure conversion passage due to each counterbore. Fluid loss is likely to occur due to the change in the cross-sectional shape due to the step, which causes a reduction in the compression efficiency of the turbo compressor.

An object of the present invention is to improve the compression efficiency of a turbo compressor.

[0006]

Means for Solving the Problems and Effects of the Invention Drawings of the following embodiments (first embodiment shown in FIGS. 1 and 2, another example of the first embodiment shown in FIGS. 3 and 4, shown in FIGS. 5 to 6) The second embodiment, the third embodiment shown in FIGS. 7 to 8, the fourth embodiment shown in FIGS. 9 to 10, the fifth embodiment shown in FIGS.
The present invention will be described with reference to the symbols of the sixth embodiment shown in FIGS.

The invention of claim 1 (corresponding to all embodiments) The turbo compressor (3) according to the present invention is configured as follows. This turbo compressor (3)
A bearing housing (7) rotatably receiving a shaft (8) for mounting an impeller (9) in a diffuser (D), and a shaft (8) of said shaft (8) with respect to the bearing housing (7) in a diffuser (D). A seal plate (11) fixed by a fastening member (21) in the vicinity of the impeller (9) on the outer periphery; and a diffuser (D) attached to the seal plate (11) so as to face the seal plate (11). And a compressor housing (6) for accommodating therein. The fastening member (21)
A counterbore (20) is formed in the seal plate (11) on the outer periphery of the shaft (8), and a pressure conversion passage (18) continuous from the impeller (9) with the diffuser (D) is formed. The passage wall part (filler 2
4 especially its surface 25 or its outer exposed surface 2
5c, lid body part 30, especially its surface 33 or its surface 33
The open end portion (20c) of the counterbore (20) is closed by the outer exposed surface 33c). Therefore, the change in the cross-sectional shape on the inner surface of the pressure conversion passage (18) is reduced by the passage wall portion (filler 24, lid body 30), and the pressure conversion passage (18) is made as flat as possible. Will be possible.

Therefore, in the present invention, the pressure conversion passage (1)
8) It is possible to improve the compression efficiency of the turbo compressor (3) by reducing the fluid loss inside. * Invention of Claim 2 (corresponding to the first embodiment and another example thereof) This invention is configured as follows on the premise of the invention of Claim 1.

The passage wall is a filler (24) embedded in the counterbore (20). This filler (24)
In the conventional structure without lubrication, lubricating oil may leak from the bearing mechanism (10) rotatably receiving the shaft (8) in the bearing housing (7) through the counterbore (20) to the pressure conversion passage (18). , Counterbore (20)
Although the oil leakage is prevented by the washer (23) supporting the fastening member (fastening screw 21), the oil leakage can be prevented by the filler (24) in the present invention. Therefore, the sealing performance of the seal plate (11) can be improved. The washer (23) can be omitted. Further, even when parts such as the bearing housing (7) are shared for cost reduction at the time of design change, the turbo compressor can be easily operated by simply burying the filler (24) in the counterbore (20). The compression efficiency of (3) can be improved.

* Invention of Claim 3 (corresponding to the second to sixth embodiments) The present invention is configured as follows based on the invention of Claim 1. Open end (2) of the counterbore (20)
And a cover (29) provided with a lid (30) covered by Oc) as the passage wall. In the present invention,
The compression efficiency of the turbo compressor (3) can be improved by a simple structure in which the cover (30) of the cover (29) is simply covered with the counterbore (20).

* Invention of Claim 4 (corresponding to the second, fourth, and fifth embodiments) The present invention is configured as follows on the premise of the invention of Claim 3. The cover (29) has a lid (30) in addition to the lid (30) as the passage wall.
From the counterbore (20) side to the counterbore (2).
0) has a fitting portion (31) to be fitted. According to the present invention, the cover body (30) of the cover (29) can be fitted to the counterbore (20) by a simple operation of merely fitting the fitting portion (31) of the cover (29) into the counterbore (20). Can be easily covered.

* Invention of Claim 5 (corresponding to the fourth, fifth, and sixth embodiments) The present invention is configured as follows, based on the invention of Claim 3 or Claim 4.

The cover (29) is interposed between the impeller (9) and the seal plate (11) on the outer periphery of the shaft (8), in addition to the lid (30) as the passage wall. The inner peripheral plate (35) is provided on the inner side closer to the shaft (8) than the lid (30). In the conventional structure without the cover (29), the heat of the lubricating oil is transmitted from the bearing mechanism (10) rotatably receiving the shaft (8) in the bearing housing (7) via the seal plate (11) to the diffuser (D). , The temperature efficiency may be adversely affected and the compression efficiency of the turbocompressor (3) may be reduced, but in the present invention, the inner peripheral plate portion (35) of the cover (29) functions as a heat shield plate. Therefore, the compression efficiency of the turbo compressor (3) can be improved with less adverse effect on the temperature efficiency. If the cover (29) is formed of a heat insulating material, the heat shielding function can be further exhibited.

* The invention of claim 6 (corresponding to the fifth and sixth embodiments) This invention is configured as follows on the premise of the invention of claim 3, claim 4, or claim 5.

The cover (29) has, in addition to the lid (30) serving as the passage wall, an outer peripheral plate (36) outside the shaft (8) farther than the lid (30). Have. In the diffuser (D), a passage wall portion forming a part of a pressure conversion passage (18) continuous from the impeller (9) is formed by the outer peripheral plate portion (36).
In the conventional structure without the cover (29), as described above, the temperature efficiency is adversely affected and the turbo compressor (3)
However, in the present invention, since the outer peripheral portion (36) of the cover (29) functions as a heat shield plate in the present invention, the adverse effect on the temperature efficiency is reduced and the turbo compressor (3) is reduced. Can improve the compression efficiency. If the cover (29) is formed of a heat insulating material, the heat shielding function can be further exhibited.

* The invention of claim 7 (corresponding to all embodiments) The present invention is configured as follows, based on the invention of any one of claims 1 to 6.

The impeller (9) includes a hub (14) attached to the shaft (8), and a plurality of blades (15) arranged in parallel in the rotation direction of the shaft (8) around the hub (14). ). In the diffuser (D), the blade passage (16) formed between the blades (15) is connected to the outer peripheral edge (14) of the hub (14).
a) connecting the pressure conversion passage (18) with the pressure conversion passage (18), and closing the open end (20c) of the counterbore (20) with a passage wall (filler 24, lid 30); The bottom surface (28) of (16) is continuous. The outer peripheral edge (14a) of the hub (14) of the rear surface (27), which is located on the hub (14) of the impeller (9) and extends around the shaft (8) on the seal plate (11) side.
Of the passage wall (filler 24, lid 3
0).

According to the present invention, the change in the cross-sectional shape at the continuous portion between the impeller (9) and the blade passage (16) and the pressure conversion passage (18) is reduced to reduce the fluid loss in the pressure conversion passage (18). And the compression efficiency of the turbo compressor (3) can be improved.

* The invention of claim 8 (corresponding to all embodiments) The turbocharger (1) according to the present invention is configured as follows. In the turbocharger (1), a compressor (3) is driven by an exhaust turbine (2) driven by exhaust gas energy to compress intake air and supply the intake air to an engine. This compressor is a turbo compressor (3) according to any one of claims 1 to 7. The bearing housing (7) is provided between the turbine housing (5) of the exhaust turbine (2) and the compressor housing (6).

According to the present invention, the turbo compressor (3)
In the turbocharger (1) provided with (1), the effect of the invention of any one of claims 1 to 7 can be effectively exhibited.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] First, a turbocharger according to a first embodiment of the present invention is shown in FIG.
This will be described with reference to FIG.

<Outline of Turbocharger 1 schematically shown in FIG. 1A> The turbocharger 1 includes an exhaust turbine 2 and a turbo compressor 3. In the exhaust turbine 2, the impeller 4 rotates by the energy of the exhaust gas. A bearing housing 7 is provided between a turbine housing 5 of the exhaust turbine 2 and a compressor housing 6 of the turbo compressor 3. An impeller 9 of the turbo compressor 3 and an impeller 4 of the exhaust turbine 2 are linked by a shaft 8 passing through the bearing housing 7. When the impeller 9 of the turbo compressor 3 rotates by the impeller 4 of the exhaust turbine 2, the intake air is compressed and supplied to the engine.

<Outline of Turbo Compressor 3 shown in FIG. 1B> A bearing mechanism 10 that rotatably receives the shaft 8 is accommodated in the bearing housing 7. At the boundary between the bearing housing 7 and the compressor housing 6, a seal plate 11 is interposed. The seal plate 11 is integrally attached to the compressor housing 6 at its outermost periphery and faces the compressor housing 6, and also closes to the impeller 9 on the outer periphery of the shaft 8 with respect to the bearing housing 7. 12 (described later). The inner peripheral portion of the seal plate 11 is supported by a retainer 13 with respect to the shaft 8. The shaft 8 penetrates through the retainer 13 and projects into the compressor housing 6. The impeller 9 is mounted on the compressor housing 6.
It is attached and accommodated so that it can rotate integrally with the shaft 8 inside.

The impeller 9 has a hub 14 attached to the shaft 8, and a rotation direction of the shaft 8 on the outer periphery of the hub 14 (the impeller 9 is connected to the rotation center line 8 of the shaft 8).
a) (in the direction of rotation about a). A blade passage 16 is formed between the blades 15. Each of the blade passages 16
The compressor housing 6 has an inlet 16a communicating with the supply port 17 and an outlet 16b having a smaller effective area than the inlet 16a. Each blade passage 16
The intake air flowing from the inlet 16a flows in the direction along the rotation center line 8a of the shaft 8, and then flows in the radial direction perpendicular to the rotation center line 8a of the shaft 8, and reaches the outlet 16b. In the compressor housing 6, the outlet 16b of each blade passage 16 is connected to the shaft 8
And a pressure conversion passage 18 extending in a radial direction orthogonal to the rotation center line 8a. Further, the pressure conversion passage 18 communicates with a scroll portion 19 provided in the compressor housing 6.

From each of the blade passages 16 to the pressure conversion passage 18
The flow path spans as a diffuser D. When the impeller 9 rotates in the compressor housing 6, the intake air sucked from the supply port 17 is compressed as it flows from each blade passage 16 to the pressure conversion passage 18 and flows out to the scroll portion 19.

<Tightening Means 12 of Seal Plate 11 to Bearing Housing 7> FIGS. 1B and 2
As shown in FIG. 3, three counterbore holes 20 are formed in the seal plate 11 at a circumferential angular interval of 120 degrees around the outer periphery of the shaft 8. In each of the counterbore holes 20, a fastening screw 21 (fastening member) is provided.
The male screw portion 21 a of the fastening screw 21 is screwed through the support hole 22 to the bearing housing 7. The head 21 b of the fastening screw 21 is supported via a washer 23 on the bottom surface 20 a of each counterbore 20. Although not shown, a fastening member such as a circlip may be employed instead of the fastening screw 21.

A filler 24 is embedded in each counterbore 20. The filler 24 is a resin-based adhesive, and the head 21 b of the fastening screw 21 is provided inside the inner peripheral surface 20 b continuous from the outer peripheral edge of the bottom surface 20 a in each counterbore 20.
After the fastening screw 21 is screwed into the space excluding the washer 23, it is poured into the space, and is exposed to the inside of the open end 20c facing the washer 23 on the bottom surface 20a. This open end 20
On the surface 25 of the filler 24 exposed inside c,
Of the inside and the outside bounded by the arc-shaped stepped portion 25a centered on the rotation center line 8a of the shaft 8, the inside exposed surface 25b is formed with a recess 26 at the inside close to the shaft 8, and An outer exposed surface 25c is formed on the outer side far from the shaft 8. The outer exposed surface 25c is closer to the pressure conversion passage 18 by the depth of the recess 26 than the inner exposed surface 25b. The portion of the filler 24 having the outer exposed surface 25c is
Is also used as a passage wall part that constitutes a part of the above.

The outer peripheral edge 1 of the hub 14 of the impeller 9
4a enters the recess 26 of the filler 24. The outer peripheral edge portion 14 of the rear surface 27 of the hub 14, which extends on the seal plate 11 side to the outer periphery of the shaft 8.
The back surface 27a is in close proximity to the inner exposed surface 25b of the filler 24. The bottom surface 28 of each blade passage 16 is smoothly continuous with the outer peripheral surface 14 c of the hub 14 in the vicinity of the outer exposed surface 25 c of the filler 24. Seal plate 1 around the open end 20c of each counterbore 20
The first surface 11a is also used as a passage wall constituting a part of the pressure conversion passage 18, and is smoothly continuous in proximity to the outer exposed surface 25c of the filler 24. The surface including the bottom surface 28, the outer exposed surface 25c, and the surface 11a is flat without any steps. In addition, the bottom surface 28 of each blade passage 16 is also disposed between the two counterbore holes 20 adjacent to each other in the rotation direction of the shaft 8.
a smoothly and continuously adjacent to the bottom surface 28 and the surface 11
The surface including a is flat without any steps.

[Another Example of First Embodiment] Next, a turbocharger according to another example of the first embodiment of the present invention is shown in FIG.
This will be described with reference to (a) and FIGS.

In the turbo compressor 3 of the turbocharger 1 according to this alternative example, the compressor housing 6 is mounted on the bearing housing 7 and the seal plate 11 is attached to the impeller 9 on the outer periphery of the shaft 8 with respect to the bearing housing 7. Proximity fastening means 12
And faces the compressor housing 6. The rest is the same as in the first embodiment.

[Second Embodiment] Next, a turbocharger according to a second embodiment of the present invention will be described with reference to FIGS. 1 (a), 5 and 6 (a).

The second embodiment is similar to the first embodiment shown in FIGS.
In place of each filler 24 in another example of the embodiment, a bottomed cylindrical cover 29 made of synthetic resin is employed. Each of the covers 29 is provided separately from each other, and includes a lid portion 30 and a fitting portion 31 protruding from an outer peripheral edge of the lid portion 30 in a cylindrical shape. The accommodation room 3 is provided in the fitting portion 31.
2 are formed. The cover 29 is elastically press-fitted into each counterbore 20 from the compressor housing 6 side, the fitting portion 31 comes into contact with the washer 23 and is fitted to the inner peripheral surface 20b, and the lid 30 is opened at the open end. It covers the entire part 20c. On the surface 33 of the lid body 30 exposed inside the open end 20 c of each counterbore 20, an arc-shaped stepped portion 33 centered on the rotation center line 8 a of the shaft 8.
The inner exposed surface 33b is formed with a recess 34 on the inner side close to the shaft 8, and the outer exposed surface 33
c is formed. The outer exposed surface 33c is smaller than the inner exposed surface 33b by a depth
Approaching 8. The outer exposed surface 3 of the lid 30
The portion having 3c is also used as a passage wall constituting a part of the pressure conversion passage 18. The step portion 33a, the inner exposed surface 33b, and the outer exposed surface 33c on the surface 33 of the lid body 30 are respectively formed on the surface 25 of the filler 24 according to another example of the first embodiment with the step portion 25a, the inner exposed surface 25b. And the outer exposed surface 25c, and the other portions are the same as the other examples of the first embodiment.

In another example of the second embodiment shown in FIG. 6 (b), an uneven rotation preventing portion 31a is formed between the fitting portion 31 of each cover 29 and the inner peripheral surface 20b of each counterbore 20. Are formed.

[Third Embodiment] Next, a turbocharger according to a third embodiment of the present invention will be described with reference to FIGS.
8 will be described.

The third embodiment is different from the first embodiment shown in FIGS.
A cover 29 is employed in place of the filler 24 in the first embodiment shown in FIG. The cover 29 is composed of a lid body 30 which is an annular plate, and is integrally fixed to the seal plate 11 on the outer periphery of the shaft 8 by adhesion or screw fastening, and faces the compressor housing 6. The annular lid 30 is covered so as to cover the outer half of the open end 20 c of each counterbore 20. The surface 33 of the lid 30 is also used as a passage wall constituting a part of the pressure conversion passage 18. The outer peripheral edge 14a of the hub 14 of the impeller 9 is opposed to the circular inner peripheral edge 30a of the annular lid 30 centered on the rotation center line 8a of the shaft 8. The bottom surface 28 of each blade passage 16 is
The outer peripheral edge 14a of the cover 4 is close to the surface 33 of the lid body 30 and smoothly continues. The surface 11 a of the seal plate 11 is also used as a passage wall that constitutes a part of the pressure conversion passage 18, and is smoothly continuous near the surface 33 of the lid 30. The surface including the bottom surface 28, the surface 33, and the surface 11a is in a flat state with no steps. The rest is the same as in the first embodiment.

Fourth Embodiment Next, a turbocharger according to a fourth embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

In the second embodiment shown in FIGS.
Although three covers 29 each having a cover 0 and a fitting portion 31 are provided separately from each other, in the fourth embodiment, a second cover 29 is provided.
Each cover 29 of the embodiment is integrated into one cover 2
It is 9. In the cover 29 of the fourth embodiment, each fitting portion 31 is press-fitted into each counterbore 20, and each lid 30 is connected to the open end 20 of each counterbore 20.
c, and is integrally fixed to the seal plate 11 on the outer periphery of the shaft 8 by bonding, screwing, or the like, and faces the compressor housing 6. Further, in the cover 29, the inner peripheral plate portion 35 is provided on the inner periphery of the shaft 8 closer to the shaft 8 than the lids 30.
Are interposed between the back surface 27 of the impeller 9 and the seal plate 11. The rest is the same as the second embodiment.

Fifth Embodiment Next, a turbocharger according to a fifth embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIGS.

In the fifth embodiment, in the fourth embodiment shown in FIGS. 9 and 10, an outer peripheral plate portion 36 is formed on the cover 29 on the outer side farther from the shaft 8 than each of the lid portions 30, and a seal is formed. The plate 11 has the outer peripheral plate 3
An outer peripheral plate portion 37 on which 6 is superimposed is formed. The outer peripheral plate portion 36 is also used as a passage wall portion that forms a part of the pressure conversion passage 18 by the diffuser D. The outermost peripheral edges of the outer peripheral plate portion 36 of the cover 29 and the outer peripheral plate portion 37 of the seal plate 11 are connected to the pressure conversion passage 1 in order to make the passage wall flat without any steps.
8 is extended to the outermost peripheral portion. The rest is the same as the fourth embodiment.

Sixth Embodiment Next, a turbocharger according to a sixth embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIGS.

In the sixth embodiment, the fitting portions 31 are omitted from the fifth embodiment shown in FIGS. 11 and 12, and the outer peripheral plate portion 37 of the seal plate 11 is omitted to reduce the weight and size. ing. The rest is the same as the fifth embodiment.

[Another Example] * In the fourth, fifth and sixth embodiments, the cover 29 is formed of a heat insulating material, and the inner peripheral plate portion 35 or the outer peripheral plate portion 36 functions as a heat shield plate. Let it.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view schematically illustrating a turbocharger according to first to sixth embodiments, and FIG. 1B is a cross-sectional view illustrating a turbocompressor of the turbocharger according to the first embodiment.

2 (a) is a partially enlarged sectional view of FIG. 1 (b), and FIG. 2 (b) is a partial sectional view taken along line 1-1 of the turbo compressor shown in FIG. 1 (b).

FIG. 3 is a partial sectional view taken along line 4-4 of the turbo compressor shown in FIG.

FIG. 4A is a sectional view showing a turbo compressor of a turbo charger according to another example of the first embodiment,
(B) is a partial enlarged sectional view of (a).

FIG. 5 is a sectional view showing a turbo compressor of a turbocharger according to a second embodiment, where (b) is (a).
It is the elements on larger scale sectional view.

6A is a partial cross-sectional view taken along line 5-5 of the turbo compressor shown in FIG. 5, and FIG.
It is a fragmentary sectional view concerning another example of an embodiment.

FIG. 7 is a sectional view showing a turbo compressor of a turbo charger according to a third embodiment, where (b) is (a).
It is the elements on larger scale sectional view.

FIG. 8 is a cross-sectional view of the turbo compressor shown in FIG.
It is a fragmentary sectional view in line 7.

FIG. 9 is a partial cross-sectional view taken along line 10-10 of the turbo compressor shown in FIG.

FIG. 10 is a cross-sectional view illustrating a turbo compressor of a turbocharger according to a fourth embodiment, and (b) is a partially enlarged cross-sectional view of (a).

FIG. 11 is a sectional view showing a turbo compressor of a turbocharger according to a fifth embodiment, and (b) is a partially enlarged sectional view of (a).

FIG. 12 is a partial cross-sectional view taken along line 11-11 of the turbo compressor shown in FIG. 11;

FIG. 13 is a partial cross-sectional view taken along line 14-14 of the turbo compressor shown in FIG.

FIG. 14 is a sectional view showing a turbo compressor of a turbocharger according to a sixth embodiment, and (b) is a partially enlarged sectional view of (a).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Turbocharger, 2 ... Exhaust turbine, 3 ... Turbo compressor, 5 ... Turbine housing, 6 ... Compressor housing, 7 ... Bearing housing, 8 ... Shaft, 9 ... Impeller, 11 ... Seal plate, 14 ... Hub, 14a ... Hub Outer peripheral edge, 15 ... blade, 16 ...
Blade passage, 18: Pressure conversion passage, 20: Counterbore, 20
c: counterbore hole open end, 21: fastening screw (fastening member),
Reference numeral 24: filler (passage wall), 27: hub rear surface, 28: blade passage bottom surface, 29: cover, 30: lid body (passage wall), 31: fitting portion, 35: cover inner peripheral plate portion, 36: Cover outer peripheral plate, D: Diffuser.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G005 EA04 EA16 FA05 FA41 FA51 GB16 GB17 GB83 GB85 3H034 AA02 AA17 BB03 BB06 CC03 DD06 DD22 DD30 EE18

Claims (8)

[Claims] A bearing housing rotatably receiving a shaft on which the impeller is mounted in the diffuser; a seal plate fixed to the bearing housing by a fastening member near the impeller on an outer periphery of the shaft with respect to the bearing housing; A turbo compressor comprising: a compressor housing that is attached to the seal plate and accommodates the impeller with a diffuser; wherein a counterbore in which the fastening member is supported is formed in the seal plate on the outer periphery of the shaft; A turbo compressor, wherein an open end of the counterbore is closed by a passage wall part of the diffuser, which constitutes a part of a pressure conversion passage continuous from the impeller. 2. The turbo compressor according to claim 1, wherein the passage wall is a filler buried in the counterbore. 3. The turbocompressor according to claim 1, further comprising a cover provided as a passage wall with a lid covering the open end of the counterbore. 4. The cover has, in addition to the lid as the passage wall, a fitting portion projecting from the lid toward the counterbore and fitted into the counterbore. The turbo compressor according to claim 3, wherein: 5. The cover is interposed between the impeller and a seal plate on the outer periphery of the shaft and closer to the shaft than the lid, in addition to the lid as the passage wall. The turbo compressor according to claim 3 or 4, further comprising an inner peripheral plate portion. 6. The cover has, in addition to a lid as the passage wall, an outer peripheral plate at an outer side farther from the shaft than the lid, and a pressure converter that is continuous from the impeller with the diffuser. The turbocompressor according to claim 3, wherein a passage wall portion forming a part of the passage is formed by the outer peripheral plate portion. 7. The impeller has a hub attached to the shaft, and a plurality of blades arranged side by side in the rotation direction of the shaft on the outer periphery of the hub, and is formed between the blades in the diffuser. A blade passage is continuous with the pressure conversion passage at an outer peripheral edge of the hub, and a bottom surface of the blade passage is continuous with a passage wall that closes an open end of the counterbore. The rear surface of the outer peripheral edge portion of the hub is made closer to the passage wall portion among the rear surface extending around the shaft on the seal plate side. The turbo compressor according to claim. 8. A compressor driven by an exhaust turbine driven by exhaust gas energy to compress intake air,
In a turbocharger for supplying the intake air to an engine, the compressor is the turbocompressor according to any one of claims 1 to 7, wherein the bearing housing is provided with a turbine housing of an exhaust turbine. A turbocharger is provided between the compressor and the compressor housing.