JP2016089717A - Centrifugal compressor and supercharger including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress failure in which the whole or one part of an impeller breaks or falls off and scatters to the outside.SOLUTION: A centrifugal compressor 1 to be provided includes: an impeller 3; an annular labyrinth packing 5 for blocking circulation of air between a seal space 6 on a back side of the impeller 3 and a discharge port 3b; a main thrust bearing 8 and an anti-thrust bearing 9 for supporting a rotor shaft 2; and a support member 11 for supporting these bearings around the rotor shaft 2. An outer peripheral edge part of the support member 11 and an inner peripheral edge part of a seal part are arranged in the seal space. The outer peripheral edge part 11a of the support member and the inner peripheral edge part 5b of the labyrinth packing 5 are arranged being close in a radial direction orthogonal to an axis X direction.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a centrifugal compressor and a supercharger including the same.

  Conventionally, a centrifugal compressor is known as a compressor of a supercharger that raises air supplied to an internal combustion engine used in a ship or the like to an atmospheric pressure or higher (see, for example, Patent Document 1). The centrifugal compressor includes an impeller attached to the rotor shaft, a guide tube that houses the impeller around the axis of the rotor shaft, and a scroll unit into which compressed air discharged from the guide tube flows. The centrifugal compressor compresses air flowing in from the intake port in the axial direction, guides it in a direction inclined from the axial direction, and discharges compressed air from the discharge port.

In the centrifugal compressor, there is a possibility that the impeller may be broken or dropped due to the centrifugal force due to the high speed rotation. In Patent Document 2, even when all or a part of the impeller (compressor impeller) is scattered in a radial direction perpendicular to the axial direction of the rotor shaft by centrifugal force, the lubricating oil does not leak out by the scattered impeller. A centrifugal compressor provided with a shock absorbing partition that protects a tank that contains lubricating oil is disclosed.
In the centrifugal compressor disclosed in Patent Document 2, the tank that stores the lubricating oil is protected when a failure occurs in which all or part of the impeller is broken or dropped due to the centrifugal force due to the high-speed rotation.

JP 2011-117417 A JP 2001-132465 A

  When all or part of the impeller is broken or dropped and scattered in the radial direction, there is a possibility that the whole or part of the broken or dropped impeller (hereinafter referred to as a breaking member) may collide with the vicinity of the discharge port. is there. When the breaking member is larger than the flow path width of the discharge port, when the breaking member collides with the vicinity of the discharge port, the vicinity of the discharge port is deformed so as to expand in the axial direction of the rotor shaft. When the impact due to the collision of the breaking member near the discharge port is not sufficiently absorbed, a crack occurs in the vicinity of the discharge port or in other portions. Due to this crack, there is a possibility that a gap (opening) is generated in a part of the outer periphery of the centrifugal compressor, and the breaking member may be scattered outside from the gap.

  The present invention has been made in view of such circumstances, and when all or part of the impeller breaks or falls off and scatters in the vicinity of the discharge port of the impeller, the fracture member scatters to the outside. It is an object of the present invention to provide a centrifugal compressor capable of suppressing the above and a supercharger including the same.

In order to achieve the above object, the present invention employs the following means.
The centrifugal compressor according to the first aspect of the present invention includes an impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port, and the impeller in the axial direction of the rotor shaft. An annular seal portion that is arranged at the outer peripheral edge portion on the back side and blocks the flow of fluid between the seal space on the back side of the impeller and the discharge port; and a bearing member that supports the rotor shaft; A support member that supports the bearing member around the rotor shaft, and an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are disposed in the seal space, respectively, and the outer peripheral edge of the support member The portion and the inner peripheral edge portion of the seal portion are arranged close to each other in the radial direction orthogonal to the axial direction.

In the centrifugal compressor according to the first aspect of the present invention, when all or a part of the impeller attached to the rotor shaft is broken or dropped by the centrifugal force accompanying the rotation of the rotor shaft, the radial direction orthogonal to the axial direction of the rotor shaft The breaking member is scattered. When the breaking member scatters in the vicinity of the discharge port of the impeller, the vicinity of the discharge port is deformed so as to expand around the axis of the rotor shaft.
Since the annular seal portion is disposed at the outer peripheral edge portion on the back side of the impeller along the rotor shaft, the seal portion near the discharge port receives an impact force that deforms in the axial direction of the rotor shaft by the breaking member.

In the centrifugal compressor according to the first aspect of the present invention, the outer peripheral edge portion of the support member arranged in the seal space and the inner peripheral edge portion of the seal portion are arranged close to each other in the radial direction. Therefore, even if the breaking member scatters in any region of the seal space on the back side of the impeller, the breaking member collides with at least one of the support member and the seal portion.
Therefore, it is possible to absorb a part of the impact force that the breaking member scattered on the back side of the impeller collides with at least one of the support member and the seal portion. Thereby, a gap is generated in a part of the centrifugal compressor due to scattering of the breaking member, and a problem that the breaking member is scattered outside from the gap can be suppressed.

In the centrifugal compressor according to the first aspect of the present invention, the seal portion may be formed of a rolled steel material.
According to this configuration, since the seal portion is formed of rolled steel, the seal portion can be appropriately plastically deformed by the collision of the rupture member, and the energy due to the collision can be absorbed.

  The centrifugal compressor according to the second aspect of the present invention includes an impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port, and the rear surface of the impeller in the axial direction of the rotor shaft An annular seal portion that is disposed at the outer peripheral edge portion on the side and blocks the flow of fluid between the seal space on the back side of the impeller and the discharge port, and the impeller and the seal portion, Are formed of materials having high pressure contact with each other.

In the centrifugal compressor according to the second aspect of the present invention, when all or a part of the impeller attached to the rotor shaft is broken or dropped by the centrifugal force accompanying the rotation of the rotor shaft, the radial direction orthogonal to the axial direction of the rotor shaft The breaking member is scattered. When the breaking member scatters in the vicinity of the discharge port of the impeller, the vicinity of the discharge port is deformed so as to expand around the axis of the rotor shaft.
Since the annular seal portion is disposed at the outer peripheral edge portion on the back side of the impeller along the rotor shaft, the seal portion near the discharge port receives an impact force that deforms in the axial direction of the rotor shaft by the breaking member.

  In the centrifugal compressor according to the second aspect of the present invention, the impeller and the seal portion are formed of materials having high pressure contact with each other. Therefore, when the breaking member collides with the seal portion, the breaking member that rotates at high speed around the rotor shaft and the seal portion are melted and pressed by frictional heat, respectively. By this pressure contact, a part of the impact force caused by the collision of the breaking member with the discharge port can be converted into heat energy and absorbed.

In the centrifugal compressor according to the second aspect of the present invention, the impeller may be formed of aluminum or an aluminum alloy, and the seal portion may be formed of aluminum or an aluminum alloy.
According to this configuration, a part of the impact force caused by the collision of the fractured member near the discharge port is converted into heat energy and absorbed by the pressure contact between the aluminum or the aluminum alloy or the pressure contact between the aluminum and the aluminum alloy. Can do.

In the centrifugal compressor according to the second aspect of the present invention, the surface of the seal portion facing the back side of the impeller may be coated with a ceramic material.
According to this configuration, a part of the impact force caused by the collision of the fracture member near the discharge port is converted into thermal energy by press-contacting the aluminum or aluminum alloy forming the impeller and the ceramic material coated on the seal portion. Can be absorbed.

  In the centrifugal compressor according to the second aspect of the present invention, the centrifugal compressor includes a bearing member that supports the rotor shaft, and a support member that supports the bearing member around the rotor shaft. An inner peripheral edge portion of the seal portion is disposed in the seal space, and an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are disposed close to each other in a radial direction orthogonal to the axial direction. It is good also as a structure.

According to this configuration, the outer peripheral edge portion of the support member arranged in the seal space and the inner peripheral edge portion of the seal portion are arranged close to each other in the radial direction. Therefore, even if the breaking member scatters in any region of the seal space on the back side of the impeller, the breaking member collides with at least one of the support member and the seal portion.
Therefore, it is possible to absorb a part of the impact force that the breaking member scattered on the back side of the impeller collides with at least one of the support member and the seal portion.

  A centrifugal compressor according to a third aspect of the present invention includes an impeller that is attached to a rotor shaft and that compresses a fluid flowing from an intake port and discharges the fluid from the discharge port, and the impeller in the axial direction of the rotor shaft. An annular seal portion that is arranged at the outer peripheral edge portion on the back side and blocks the flow of fluid between the seal space on the back side of the impeller and the discharge port; and a bearing member that supports the rotor shaft; A support member for supporting the bearing member around the rotor shaft, wherein the support member and the seal portion are integrally formed, and a connecting portion between the support member and the seal portion is formed in the seal space. Be placed.

According to the centrifugal compressor according to the third aspect of the present invention, the connecting portion of the support member and the seal portion that are integrally formed is disposed in the seal space. Therefore, even if the breaking member scatters in any region of the seal space on the back side of the impeller, the breaking member collides with the vicinity of the connecting portion that integrally connects the support member and the seal portion.
Therefore, it is possible to absorb a part of the impact force that the breaking member scattered on the back side of the impeller collides with at least one of the support member and the seal portion.

  In the centrifugal compressor according to the fourth aspect of the present invention, the impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port, and the impeller in the axial direction of the rotor shaft An annular seal portion that is disposed on the outer peripheral portion of the rear side of the impeller and blocks the flow of fluid between the seal space on the rear side of the impeller and the discharge port, and a bearing member that supports the rotor shaft A support member that supports the bearing member around the rotor shaft, and an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are disposed in the seal space, respectively, The peripheral edge portion and the inner peripheral edge portion of the seal portion are arranged so as to be close to each other in the axial direction and overlap in the radial direction orthogonal to the axial direction.

According to the centrifugal compressor which concerns on the 4th aspect of this invention, it arrange | positions so that the outer peripheral part of the supporting member arrange | positioned in seal space and the inner peripheral part of a seal part may overlap in a radial direction. Therefore, even if the breaking member scatters in any region of the seal space on the back side of the impeller, the breaking member collides with at least one of the support member and the seal portion. Further, when the breaking member collides with either the support member or the seal portion arranged on the impeller side, the impact force due to the collision is transmitted to either the support member or the seal portion.
Therefore, both the support member and the seal part absorb a part of the impact force that the breaking member scattered on the back side of the impeller collides with either the support member or the seal part arranged on the impeller side. Can do.

In the centrifugal compressor according to the fourth aspect of the present invention, the outer peripheral edge portion of the support member may be disposed closer to the impeller side in the axial direction than the inner peripheral edge portion of the seal portion.
In this way, when the breaking member collides with the support member, the impact force of the breaking member colliding with the support member is transmitted to the seal portion, and a part of the impact force is absorbed by both the support member and the seal portion. can do.

A turbocharger according to an aspect of the present invention includes a centrifugal compressor according to any one of the above, a turbine that rotates around the axis by exhaust gas discharged from an internal combustion engine and is connected to the rotor shaft, Is provided.
According to the supercharger according to one aspect of the present invention, when all or part of the impeller breaks or falls off and scatters in the radial direction perpendicular to the axial direction of the rotor shaft, the rupture member scatters to the outside. Problems can be suppressed.

  According to the present invention, when all or a part of the impeller is broken or dropped and scattered near the discharge port of the impeller, a centrifugal compressor capable of suppressing a problem that the broken member is scattered outside, and A supercharger equipped with the same can be provided.

It is a longitudinal section showing a supercharger provided with a centrifugal compressor of a 1st embodiment. It is a longitudinal cross-sectional view which shows a supercharger provided with the centrifugal compressor of 2nd Embodiment. It is a longitudinal cross-sectional view which shows a supercharger provided with the centrifugal compressor of 4th Embodiment.

[First Embodiment]
Hereinafter, the supercharger of 1st Embodiment of this invention is demonstrated with reference to drawings.
The supercharger 100 of the present embodiment is a device that raises the air (gas) supplied to a marine diesel engine (internal combustion engine) used in a marine vessel to an atmospheric pressure or higher and increases the combustion efficiency of the marine diesel engine.
The supercharger 100 of this embodiment includes the centrifugal compressor 1 and a turbine (not shown) shown in FIG. The centrifugal compressor 1 and the turbine are each connected to the rotor shaft 2.

The centrifugal compressor 1 compresses air flowing in from the outside of the supercharger 100 and compresses air into a scavenging trunk (not shown) that communicates with the inside of a cylinder liner (not shown) that constitutes a marine diesel engine (hereinafter, referred to as “the air compressor”). This is a device that supplies compressed air (compressed fluid).
The centrifugal compressor 1 includes a rotor shaft 2, an impeller 3, a casing 4, a labyrinth packing 5 (seal part), a bearing base 7, a main thrust bearing 8, an anti-thrust bearing 10, and a support member 11. Prepare.

  The turbine (not shown) is a device that applies a rotational force around the axis X to a plurality of turbine blades attached at regular intervals around the axis X of the rotor shaft 2 by exhaust gas discharged from a marine diesel engine. The rotor shaft 2 rotates about the axis X by the rotational force applied to the plurality of turbine blades.

  As the rotor shaft 2 rotates around the axis X, the impeller 3 connected to the rotor shaft 2 rotates, the air flowing from the intake port 3a is compressed, and the compressed air is discharged from the discharge port 3b. The compressed air discharged from the discharge port 3b flows into a scroll portion (not shown) and is guided to a scavenging trunk of a marine diesel engine.

Next, each structure with which the centrifugal compressor 1 is provided is demonstrated.
As shown in FIG. 1, the impeller 3 is attached to the rotor shaft 2 extending along the axis X, and rotates about the axis X as the rotor shaft 2 rotates about the axis X. The impeller 3 rotates around the axis X, thereby compressing the air flowing in from the intake port 3a and discharging it from the discharge port 3b. The impeller 3 is made of aluminum or an aluminum alloy.

  The impeller 3 includes a hub 3c attached to the rotor shaft 2 and a blade 3d attached on the outer peripheral surface of the hub 3c. The impeller 3 is provided with a space formed by the outer peripheral surface of the hub 3c and the inner peripheral surface of the casing 4, and this space is partitioned into a plurality of spaces by a plurality of blades 3d. The impeller 3 applies a radial centrifugal force to the air flowing in from the intake port 3a along the axis X direction and discharges it in a direction perpendicular to the axis X direction (radial direction of the impeller 3). The compressed air discharged from the outlet 3b is caused to flow into the diffuser 12.

  The casing 4 is a member that accommodates the impeller 3 around the axis X of the rotor shaft 2 and discharges air flowing in from the intake port 3a along the axis X direction of the rotor shaft 2 to the discharge port 3b. The casing 4, together with the impeller 3, forms a flow path that guides the air flowing from the intake port 3 a along the axis X to the discharge port 3 b in the radial direction orthogonal to the axis X.

  The labyrinth packing 5 (seal part) is an annular member that blocks the flow of compressed air between the seal space 6 on the back side of the impeller 3 and the discharge port 3 b of the impeller 3. The labyrinth packing 5 is disposed on the outer peripheral edge of the impeller 3 on the back surface 3 e side in the axis X direction of the rotor shaft 2.

  Fins 3 f (annular convex portions) are formed on the outer peripheral edge portion of the back surface 3 e of the impeller 3. Each of the fins 3f is formed of a plurality of endless convex portions extending around the axis X. The plurality of convex portions have different radii with respect to the axis X.

  On the other hand, the labyrinth packing 5 is formed with an annular groove 5a at a position facing the fin 3f. The annular groove 5a is formed from a plurality of endless grooves extending around the axis X. The plurality of grooves have different radii with respect to the axis X. Further, the radii of the plurality of groove portions respectively coincide with the radii of the plurality of convex portions forming the fins 3f.

  At the position where the fin 3f and the labyrinth packing 5 face each other, the plurality of convex portions forming the fin 3f are arranged in a state of being inserted into the plurality of groove portions forming the annular groove portion 5a. The space between the fin 3f and the labyrinth packing 5 is maintained at a minute interval by the plurality of convex portions and the plurality of groove portions. Thereby, the flow of compressed air between the seal space 6 and the discharge port 3b is blocked.

The labyrinth packing 5 of this embodiment is formed of a rolled steel material that is a metal member manufactured by rolling. This rolled steel material is an Fe-C-based alloy containing iron as a main component and containing a small amount of carbon (about 0.2%). As the rolled steel material, it is preferable to use, for example, a general structural rolled steel material called SS400 (JIS G 3101; ASTM A283).
The labyrinth packing 5 is formed by cutting a plate-shaped rolled steel material.

  As a member for forming the labyrinth packing 5, generally, cast iron which is an Fe—C alloy containing iron as a main component and containing 2% or more of carbon is used. As cast iron, gray cast iron or ductile cast iron (FCD: Ferrum Casting Ductile) is used. A metal material obtained by casting tends to form a complicated shape by casting, but is more likely to be brittle fracture than other metal materials such as rolled steel.

  In the present embodiment, a rolled steel material that is an Fe—C alloy manufactured by rolling is used as a member that forms the labyrinth packing 5. A rolled steel material is a steel material produced by applying plastic deformation using a rolling mill, and generally has a characteristic that the ductility is larger than a metal material obtained by casting.

  The bearing stand 7 is a member that houses the labyrinth packing 5, a main thrust bearing 8, which will be described later, an anti-thrust bearing 10, and a support member 11 in the axis X of the rotor shaft 2. The bearing base 7 is further formed with a flow path 7a penetrating in the axis X direction.

The flow path 7 a is a flow path for discharging a small amount of compressed air flowing into the seal space 6 through a minute gap between the fin 3 f and the labyrinth packing 5 to the outside of the seal space 6. By releasing the compressed air in the seal space 6 to the outside, the pressure in the seal space 6 can be reduced.
Thereby, the thrust which presses the rotor shaft 2 in the direction of the inlet 3a of the impeller 3 by the compressed air is reduced.

  The main thrust bearing 8 and the anti-thrust bearing 10 are bearing members that support the rotor shaft 2 in the axis X direction. The main thrust bearing 8 and the anti-thrust bearing 10 are disposed in a state where a thrust collar 9 formed integrally with the rotor shaft 2 is sandwiched in the axis X direction. The rotor shaft 2 is given a thrust in a direction in which the thrust collar 9 is moved to the intake port 3a side of the impeller 3 by a turbine (not shown).

  The main thrust bearing 8 supports the thrust in the axis X direction applied from the thrust collar 9. Similarly, the anti-thrust bearing 10 supports the thrust in the axis X direction applied from the thrust collar 9. The main thrust bearing 8 supports thrust in the axis X direction applied by the turbine, and the anti-thrust bearing 10 supports thrust in the opposite direction.

The main thrust bearing 8 is attached to the support member 11, and the anti-thrust bearing 10 is attached to the bearing base 7.
The support member 11 is a member that supports the main thrust bearing 8 around the rotor shaft 2. The support member 11 is connected to the bearing stand 7 by a plurality of fastening bolts (not shown).

As shown in FIG. 1, the outer peripheral edge portion 11 a of the support member 11 and the inner peripheral edge portion 5 b of the labyrinth packing 5 are respectively disposed in the seal space 6. In addition, the outer peripheral edge portion 11a and the inner peripheral edge portion 5b are disposed close to each other in the radial direction orthogonal to the axis X direction.
It is desirable that the radial distance between the outer peripheral edge portion 11a and the inner peripheral edge portion 5b is such a distance that the rupture member does not pass toward the bearing stand 7 without coming into contact therewith.

  For example, the radial distance between the outer peripheral edge portion 11a and the inner peripheral edge portion 5b is within a range of 15% or less of the outer diameter of the labyrinth packing 5 (the radial distance from the axis X to the outer peripheral edge portion of the labyrinth packing 5). It is preferable to do this. More preferably, the radial distance between the outer peripheral edge portion 11 a and the inner peripheral edge portion 5 b is in the range of 6% or more and 10% or less of the outer diameter of the labyrinth packing 5. By setting it as such a range, it can suppress that a fracture | rupture member passes toward the bearing stand 7, without contacting any of the labyrinth packing 5 and the support member 11. FIG.

The operation and effect of the supercharger 100 of the present embodiment described above will be described.
In the centrifugal compressor 1 provided in the supercharger 100 of the present embodiment, when all or a part of the impeller 3 attached to the rotor shaft 2 is broken or dropped by the centrifugal force accompanying the rotation of the rotor shaft 2, the rotor shaft 2 Breaking members are scattered in the radial direction orthogonal to the axis X direction.

When the breaking member scatters in the vicinity of the discharge port 3 b of the impeller 3, the vicinity of the discharge port 3 b is deformed so as to expand around the axis X of the rotor shaft 2.
Since the annular labyrinth packing 5 is arranged on the outer peripheral edge of the impeller 3 along the rotor shaft 2 on the back surface 3e side, the labyrinth packing 5 near the discharge port 3b is moved by the breaking member in the direction of the axis X of the rotor shaft 2 It receives an impact force that deforms.

  In the centrifugal compressor 1 of the present embodiment, since the labyrinth packing 5 is formed of a rolled steel material, the labyrinth packing 5 is appropriately plastically deformed by the collision of the fracture member, and absorbs the energy due to the collision. Thereby, a clearance gap arises in a part of centrifugal compressor 1 when a fracture member scatters, and the fault that a fracture member scatters outside from the clearance gap can be controlled.

According to the present embodiment, the outer peripheral edge portion 11 a of the support member 11 arranged in the seal space 6 and the inner peripheral edge portion 5 b of the labyrinth packing 5 are arranged close to each other in the radial direction. Therefore, even if the breaking member scatters in any region of the seal space 6 on the back surface 3 e side of the impeller 3, the breaking member collides with at least one of the support member 11 and the labyrinth packing 5.
Therefore, it is possible to absorb a part of the impact force that the breaking member scattered on the back surface 3 e side of the impeller 3 collides with at least one of the support member 11 and the labyrinth packing 5.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. The second embodiment is a modification of the first embodiment. Except for the case where it is specifically described below, it is assumed to be the same as that of the first embodiment, and a description thereof will be omitted.
In the first embodiment, the outer peripheral edge portion 11a of the support member 11 and the inner peripheral edge portion 5b of the labyrinth packing 5 are arranged close to each other in the radial direction orthogonal to the axis X direction.
On the other hand, the centrifugal compressor 1 ′ of the present embodiment shown in FIG. 2 is arranged so that the outer peripheral edge portion 11′a of the support member 11 ′ and the inner peripheral edge portion 5′b of the labyrinth packing 5 ′ overlap in the radial direction. To do.

As shown in FIG. 2, the labyrinth packing 5 ′ included in the centrifugal compressor 1 ′ of the supercharger 100 ′ of the present embodiment includes an annular groove portion 5 ′ a formed at a position facing the fin 3 f and an inner peripheral edge portion. 5′b.
Further, the support member 11 ′ of the present embodiment has an outer peripheral edge portion 11′a.

  As shown in FIG. 2, the outer peripheral edge portion 11 ′ a of the support member 11 ′ and the inner peripheral edge portion 5 ′ b of the labyrinth packing 5 ′ are arranged so as to overlap in the radial direction. Further, the outer peripheral edge 11 ′ a of the support member 11 ′ is disposed closer to the impeller 3 in the axis X direction than the inner peripheral edge 5 ′ b of the labyrinth packing 5 ′.

  According to the present embodiment, the outer peripheral edge portion 11 ′ a of the support member 11 ′ disposed in the seal space 6 and the inner peripheral edge portion 5 ′ b of the labyrinth packing 5 ′ are arranged so as to overlap in the radial direction. Therefore, even if the breaking member scatters in any region of the seal space 6 on the back surface 3e side of the impeller 3, the breaking member collides with at least one of the support member 11 'and the labyrinth packing 5'.

  Further, when the breaking member collides with the support member 11 ′ arranged on the impeller 3 side, the impact force due to the collision is transmitted to the labyrinth packing 5 ′. Therefore, a part of impact force that the breaking member scattered on the back surface 3e side of the impeller 3 collides with the support member 11 ′ disposed on the impeller 3 side is absorbed by both the support member 11 ′ and the labyrinth packing 5 ′. can do.

In the present embodiment, the outer peripheral edge portion 11′a of the support member 11 ′ is arranged on the impeller 3 side, and the inner peripheral edge portion 5′b of the labyrinth packing 5 ′ is arranged on the bearing stand 7 side. However, other embodiments may be used.
For example, the inner peripheral edge 5′b of the labyrinth packing 5 ′ may be disposed on the impeller 3 side, and the outer peripheral edge 11′a of the support member 11 ′ may be disposed on the bearing base 7 side.

  In the case of another aspect, when the breaking member collides with the labyrinth packing 5 ′ disposed on the impeller 3 side, the impact force due to the collision is transmitted to the support member 11 ′. Therefore, a part of the impact force that the breaking member scattered on the back surface 3e side of the impeller 3 collides with the labyrinth packing 5 ′ disposed on the impeller 3 side is absorbed by both the support member 11 ′ and the labyrinth packing 5 ′. can do.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. The third embodiment is a modification of the first embodiment and the second embodiment. Except for the case where it is specifically described below, it is the same as the first embodiment and the second embodiment, and the description is omitted.

In the first embodiment and the second embodiment, the labyrinth packing 5 (labyrinth packing 5 ′) is formed of a rolled steel material, and the impact force due to the collision of the fracture member is absorbed by the ductility of the rolled steel material.
In contrast, in the present embodiment, the impeller 3 and the labyrinth packing 5 (labyrinth packing 5 ′) are formed of materials that are highly press-contactable with each other.

  The impeller 3 included in the centrifugal compressor 1 rotates at a very high rotational speed of, for example, 10,000 revolutions per minute or more. Therefore, when a part of the impeller 3 is broken or dropped and scattered in the vicinity of the discharge port 3b, the broken member collides with the labyrinth packing 5 (labyrinth packing 5 ′) in the vicinity of the discharge port 3b and rotates around the axis X at a high speed. Rotate to. At this time, a large frictional heat is generated between the labyrinth packing 5 (labyrinth packing 5 ') and the breaking member.

  When the labyrinth packing 5 (labyrinth packing 5 ′) and the rupture member (part of the impeller 3) are made of a material having a high friction pressure, large friction is generated between the labyrinth packing 5 (labyrinth packing 5 ′) and the rupture member. Each is melted and pressed by heat. By this pressure contact, a part of the impact force caused by the collision of the breaking member with the discharge port 3b can be converted into heat energy and absorbed.

  Therefore, in the present embodiment, the impeller 3 and the labyrinth packing 5 (labyrinth packing 5 ′) are made of materials having high friction welding properties. Specifically, the impeller 3 is formed of aluminum or an aluminum alloy, and the labyrinth packing 5 (labyrinth packing 5 ') is formed of aluminum or an aluminum alloy.

  In the centrifugal compressor 1 of the present embodiment, the impeller 3 and the labyrinth packing 5 (labyrinth packing 5 ') are formed of materials having high pressure contact with each other. Therefore, when the breaking member collides with the labyrinth packing 5 (labyrinth packing 5 ′), the breaking member that rotates at high speed around the rotor shaft 2 and the labyrinth packing 5 (labyrinth packing 5 ′) are respectively melted by frictional heat. Press contact. By this pressure contact, a part of the impact force caused by the collision of the breaking member near the discharge port 3b can be converted into heat energy and absorbed.

In the centrifugal compressor 1 of this embodiment, the impeller is formed of aluminum or an aluminum alloy, and the labyrinth packing 5 (labyrinth packing 5 ′) is formed of aluminum or an aluminum alloy.
According to the present embodiment, a part of the impact force caused by the collision of the fracture member near the discharge port 3b is converted into heat energy and absorbed by the pressure contact between the aluminum or the aluminum alloy or the pressure contact between the aluminum and the aluminum alloy. can do.

In addition, although this embodiment formed the labyrinth packing 5 (labyrinth packing 5 ') with aluminum or an aluminum alloy, another aspect may be sufficient.
For example, the labyrinth packing 5 (labyrinth packing 5 ′) may be cast using cast iron that is an Fe—C alloy, and the surface facing the rear surface 3e of the impeller 3 may be coated with a ceramic material.

  Ceramic materials are known to have high pressure contact to aluminum and aluminum alloys. Therefore, the surface of the labyrinth packing 5 (labyrinth packing 5 '), which the rupture member contacts when the rupture member collides with the discharge port 3b, is coated with a ceramic material.

  According to this aspect, the impact force due to the collision of the fracture member near the discharge port 3b due to the pressure contact between the aluminum or aluminum alloy forming the impeller 3 and the ceramic material coated on the labyrinth packing 5 (labyrinth packing 5 ′). A part of can be converted into heat energy and absorbed.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. The fourth embodiment is a modification of the first embodiment. Except for the case where it is specifically described below, it is assumed to be the same as that of the first embodiment, and a description thereof will be omitted. The bearing base 7 of the present embodiment is different from the bearing base 7 of the first embodiment in that the flow path 7a is not formed.

In the first embodiment, the labyrinth packing 5 and the support member 11 are formed as separate members.
On the other hand, the centrifugal compressor 1 ″ included in the supercharger 100 ″ of the present embodiment shown in FIG. 3 is one in which the labyrinth packing 5 ″ and the support member 11 ″ are integrally formed.

  As shown in FIG. 3, the centrifugal compressor 1 ″ included in the supercharger 100 ″ of the present embodiment includes a labyrinth packing 5 ″ (seal part) and a support member 11 ″. The labyrinth packing 5 ″ and the support member 11 ″ are integrally formed via the connecting portion 13. In the labyrinth packing 5 ″, an annular groove 5 ″ a is formed at a position facing the fin 3 f.

According to the present embodiment, the connecting portion 13 between the support member 11 ″ and the labyrinth packing 5 ″ that are integrally formed is disposed in the seal space 6. Therefore, even if the breaking member scatters in any region of the seal space 6 on the back surface 3e side of the impeller 3, the breaking member collides with the connecting portion 13 that integrally connects the support member 11 '' and the labyrinth packing 5 ''. To do.
Therefore, it is possible to absorb a part of the impact force that the breaking member scattered on the back surface 3e side of the impeller 3 collides with at least one of the support member 11 ″ and the labyrinth packing 5 ″.

  The support member 11 ″ and the labyrinth packing 5 ″ are formed by casting using, for example, aluminum or an aluminum alloy. By forming the support member 11 ″ and the labyrinth packing 5 ″ using aluminum or an aluminum alloy, the press contact property between these members and the breaking member (the impeller 3) can be improved.

[Other Embodiments]
In the above description, the rotor shaft 2 to which the impeller 3 included in the centrifugal compressor 1 is connected is rotated around the axis X by the turbine rotated by the exhaust gas discharged from the marine diesel engine. The aspect of this may be sufficient. For example, the rotor shaft 2 may be rotated by another power source such as a motor connected to the rotor shaft 2.

1, 1 ', 1 "Centrifugal compressor 2 Rotor shaft 3 Impeller 4 Casing 5, 5', 5" Labyrinth packing (seal part)
6 Seal space 7 Bearing stand 8 Main thrust bearing (bearing member)
9 Thrust collar 10 Anti-thrust bearing (bearing member)
11, 11 ′, 11 ″ support member 12 diffuser 100, 100 ′, 100 ″ turbocharger X axis

Claims (10)

An impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port;
An annular seal portion that is disposed on the outer peripheral edge portion on the back surface side of the impeller in the axial direction of the rotor shaft, and that blocks the flow of fluid between the seal space on the back surface side of the impeller and the discharge port; ,
A bearing member for supporting the rotor shaft;
A support member for supporting the bearing member around the rotor shaft,
An outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are respectively disposed in the seal space;
A centrifugal compressor in which an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are arranged close to each other in a radial direction orthogonal to the axial direction.   The centrifugal compressor according to claim 1, wherein the seal portion is formed of a rolled steel material. An impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port;
An annular seal portion that is disposed on the outer peripheral edge portion on the back surface side of the impeller in the axial direction of the rotor shaft, and that blocks the flow of fluid between the seal space on the back surface side of the impeller and the discharge port; With
The impeller and the seal portion are centrifugal compressors formed of materials having high pressure contact with each other. The impeller is formed of aluminum or an aluminum alloy;
The centrifugal compressor according to claim 3, wherein the seal portion is formed of aluminum or an aluminum alloy.   The centrifugal compressor according to claim 3, wherein a surface of the seal portion facing the back side of the impeller is coated with a ceramic material. A bearing member for supporting the rotor shaft;
A support member for supporting the bearing member around the rotor shaft,
An outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are respectively disposed in the seal space;
The centrifugal compressor according to any one of claims 3 to 5, wherein an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are disposed close to each other in a radial direction orthogonal to the axial direction. . An impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port;
An annular seal portion that is disposed on the outer peripheral edge portion on the back surface side of the impeller in the axial direction of the rotor shaft, and that blocks the flow of fluid between the seal space on the back surface side of the impeller and the discharge port; ,
A bearing member for supporting the rotor shaft;
A support member for supporting the bearing member around the rotor shaft,
A centrifugal compressor in which the support member and the seal portion are integrally formed, and a connecting portion between the support member and the seal portion is disposed in the seal space. An impeller that is attached to the rotor shaft and compresses the fluid flowing from the intake port and discharges it from the discharge port;
An annular seal portion that is disposed on the outer peripheral edge portion on the back surface side of the impeller in the axial direction of the rotor shaft, and that blocks the flow of fluid between the seal space on the back surface side of the impeller and the discharge port; ,
A bearing member for supporting the rotor shaft;
A support member for supporting the bearing member around the rotor shaft,
An outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are respectively disposed in the seal space;
A centrifugal compressor in which an outer peripheral edge portion of the support member and an inner peripheral edge portion of the seal portion are arranged so as to be close in the axial direction and overlap in a radial direction orthogonal to the axial direction.   The centrifugal compressor according to claim 8, wherein an outer peripheral edge portion of the support member is disposed closer to the impeller side in the axial direction than an inner peripheral edge portion of the seal portion. The centrifugal compressor according to any one of claims 1 to 9,
A turbocharger comprising: a turbine that rotates around the axis by exhaust gas discharged from an internal combustion engine and is coupled to the rotor shaft.

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