JP6517386B2 - Centrifugal compressor and supercharger - Google Patents

Description

  The present invention relates to a centrifugal compressor and a supercharger.

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

  In a centrifugal compressor, there is a possibility that a failure may occur in which part of the impeller is broken or dropped due to the influence of centrifugal force due to high speed rotation. Patent Document 2 discloses an impact that protects a tank containing lubricating oil so that the lubricating oil is not leaked by the scattered impeller even when a part of the impeller (compressor impeller) is scattered outward by centrifugal force. A centrifugal compressor provided with an absorbing bulkhead is disclosed.

JP, 2011-117417, A JP 2001-132465 A

In the centrifugal compressor disclosed in Patent Document 2, when a failure that a part of the impeller is broken or dropped due to the influence of the centrifugal force due to high speed rotation, the tank for containing the lubricating oil is protected.
However, when all or part of the impeller breaks or falls off and collides with the guide cylinder, the guide cylinder is broken because the impact load is large, and all or part of the guide cylinder along with all or part of the impeller May scatter outside. Further, even when the guide cylinder is not broken, the whole or a part of the guide cylinder may come off from the mounting position and may be scattered in the direction away from the scroll portion along the axis of the rotor shaft. In this case, there is a possibility that a gap (opening) is generated in a part of the centrifugal compressor by scattering of all or a part of the guide cylinder, and a broken part of the impeller may scatter to the outside from the gap.

  The present invention has been made in view of such circumstances, and when all or part of the guide cylinder is scattered as all or part of the impeller is broken or dropped, the whole of the impeller is removed. Or it aims at providing a centrifugal compressor and a supercharger provided with the same which can control a failure which a part scatters outside.

In order to achieve the above object, the present invention adopts the following means.
In a centrifugal compressor according to one aspect of the present invention, an impeller mounted on a rotor shaft and compressing a fluid flowing in from an intake port and discharging the fluid from a discharge port, a guide cylinder housing the impeller, the guide A scroll portion having a scroll casing which is disposed on the outer peripheral side of a cylinder and which forms a vortex chamber into which the compressed fluid discharged from the discharge port flows, a bearing portion for supporting the rotor shaft, and the scroll portion A bearing base having a flange portion, the flange portion and the scroll casing, a plurality of flange portion fastening bolts extending in the axial direction at a plurality of fastening positions around the axis of the rotor shaft, and an outer peripheral edge of the flange portion And a recess surrounding the outer periphery of the scroll casing from the outer peripheral side, and opening in the recess and extending along the axial direction A plurality of clamp members having through holes, and any one of the flange portion and the scroll casing has a plurality of fastening holes extending in the axial direction in the circumferential direction around the axis, and the flange portion or the scroll One of the scroll casings and the clamp member are fastened by a clamp member fastening bolt inserted into the through hole and the fastening hole, and the other of the flange portion or the scroll casing in the axial direction A predetermined gap is provided between the end face and the end face in the axial direction of the recess.

  According to the centrifugal compressor according to one aspect of the present invention, even when the flange portion of the bearing stand is separated from the scroll casing due to breakage of the plurality of flange portion fastening bolts, the flange portion or the scroll casing Any other axial end face contacts the axial end face of the recess. The impact due to this contact is absorbed by a plurality of clamping members mounted circumferentially around the axis. Thus, it is possible to suppress a problem in which a gap is generated in a part of the centrifugal compressor due to scattering of all or part of the impeller, and all or part of the impeller that is damaged from the gap is scattered to the outside.

The embodiment smell Te, the flange portion, which has the fastening hole is fastened by the clamp member and the clamp member fastening bolt, and an end face of the axial direction of the scroll casing, in the axial direction of said recess predetermined gap is provided between the end face, said flange portion, said a contact surface in contact with the scroll casing, said contact surfaces before Symbol stream than with the compressed fluid to form a to that channel distribution It may have a step part which connects with the end face of the flange part arranged on the road side.

By doing this, when a plurality of flange portion fastening bolts are broken, the flange portion of the bearing stand and the scroll casing are separated, and the axial end face of the scroll casing contacts the axial end face of the recess. The presence of the step suppresses the opening between the flange and the scroll casing.
Further, the opening can be more reliably suppressed by making the axial width of the step portion wider than the width of the predetermined gap.

A supercharger according to the present invention comprises: the centrifugal compressor according to any one of the above, and a turbine rotated about the axis by exhaust gas discharged from an internal combustion engine and coupled to the rotor shaft. It is characterized by
According to the turbocharger according to the present invention, the guide cylinder provided in the centrifugal compressor scatters to form a gap in a part of the centrifugal compressor, and the problem that a part of the impeller scatters to the outside from the gap is suppressed can do.

  According to the present invention, when all or part of the guide cylinder is scattered as all or part of the impeller is broken or dropped, it is possible to suppress the problem that all or part of the impeller is scattered to the outside It is possible to provide a centrifugal compressor that can be used and a turbocharger equipped with the same.

It is a longitudinal section showing one embodiment of a supercharger. It is AA arrow sectional drawing of the silencer shown in FIG. It is BB arrow sectional drawing of the silencer shown in FIG. It is the elements on larger scale which show the fastening position vicinity of the silencer casing and scroll casing shown in FIG. It is the elements on larger scale which show the fastening position vicinity of the scroll casing and flange part which are shown in FIG. It is the figure which looked at the scroll casing and the outer peripheral edge part of the flange part from P direction shown in FIG. It is CC arrow sectional drawing of the scroll casing shown in FIG. 6, and the outer-periphery edge part of a flange part, and is a figure which shows the state which a scroll casing and a flange part contacted. It is CC arrow sectional drawing of the scroll casing shown in FIG. 6, and the outer-periphery edge part of a flange part, and is a figure which shows the state which a scroll casing and a flange part spaced apart.

The turbocharger 100 of the present embodiment will be described with reference to the drawings.
The turbocharger 100 of the present embodiment is a device that raises the air (gas) supplied to a marine diesel engine (internal combustion engine) used for a ship to a pressure higher than atmospheric pressure to enhance the combustion efficiency of the marine diesel engine.
As shown in FIG. 1, the turbocharger 100 of the present embodiment includes a centrifugal compressor 10, a turbine (not shown), and a bearing stand 20. The centrifugal compressor 10 and the turbine are connected to the rotor shaft 30, respectively. The rotor shaft 30 is supported by the bearing stand 20 so as to be rotatable about the axis X.

  The centrifugal compressor 10 compresses air flowing from the outside of the turbocharger 100, and compressed into an intake manifold (not shown) communicating with the inside of a cylinder liner (not shown) constituting a marine diesel engine (hereinafter referred to as “the air”). It is a device that supplies compressed air (compressed fluid). The centrifugal compressor 10 includes an impeller 11, an air guide cylinder 12 (guide cylinder), a scroll portion 13, a partition plate 14, and a silencer 15.

  The turbocharger 100 according to the present embodiment guides the exhaust gas discharged from a marine diesel engine to a turbine, and rotates a turbine disk on which a turbine blade is mounted around an axis X. The impeller 11 connected via the rotor shaft 30 rotates with the rotation of the turbine disk, and the air flowing in from the inlet 11a is compressed, and the compressed air is discharged from the outlet 11b. The compressed air discharged from the discharge port 11 b flows into the scroll portion 13 and is guided to the intake manifold of the marine diesel engine.

  The air guide cylinder 12 and the scroll portion 13 are made of metal members manufactured by casting to form a complicated shape. As this metal member, for example, cast iron which is an Fe-C based alloy containing iron as a main component and 2% or more of carbon is used. It is possible to use various materials such as gray cast iron if it is cast iron, but it is preferable to use ductile cast iron (FCD: Ferrum Casting Ductile) in which black smoke in base tissue is spheroidized. The cast metal material tends to form a complicated shape by casting, but has brittleness.

Next, each component of the centrifugal compressor 10 will be described.
As shown in FIG. 1, the impeller 11 is attached to a rotor shaft 30 extending along the axis X, and rotates around the axis X as the rotor shaft 30 rotates around the axis X. The impeller 11 rotates around the axis X to compress the air flowing in from the inlet 11 a and discharge the air from the outlet 11 b.

  As shown in FIG. 1, the impeller 11 includes a hub 11c attached to the rotor shaft 30, a blade 11d attached on the outer peripheral surface of the hub 11c, and a flow passage 11e. The impeller 11 is provided with a space defined by the outer peripheral surface of the hub 11c and the inner peripheral surface of the air guiding cylinder 12, and this space is partitioned into a plurality of spaces by a plurality of blades 11d. Then, the impeller 11 applies centrifugal force in the radial direction to the air flowing in from the intake port 11a along the axis X direction, and discharges it in a direction (radial direction of the impeller 11) orthogonal to the axis X direction. The compressed air discharged from the outlet 11b is made to flow into the diffuser 13a.

  The air guide cylinder 12 is a member that accommodates the impeller 11 and discharges, from the discharge port 11 b, air flowing in from the intake port 11 a along the axis X direction of the rotor shaft 30. The air guide cylinder 12, together with the impeller 11, forms a flow passage 11e which guides the air flowing in from the inlet 11a along the axis X in the radial direction perpendicular to the axis X to the outlet 11b.

  The scroll unit 13 is a device for receiving the compressed air discharged from the discharge port 11b and converting kinetic energy (dynamic pressure) applied to the compressed air into pressure energy (static pressure). The scroll portion 13 is disposed on the outer peripheral side in the radial direction orthogonal to the axial line X direction with respect to the air guide cylinder 12.

  The scroll unit 13 includes a diffuser 13a, a scroll casing 13b, and a spiral chamber 13c. The vortex chamber 13c is a space formed by the scroll casing 13b. As shown in FIG. 2, the scroll casing 13 b is connected to the flange portion 20 a of the bearing stand 20 by a fastening bolt 41.

  The diffuser 13a is an airfoil-shaped member disposed on the downstream side of the discharge port 11b of the impeller 11, and forms a flow path for guiding the compressed air from the discharge port 11b to the spiral chamber 13c. The diffuser 13 a is provided so as to surround the discharge port 11 b of the compressed air provided around the entire circumference of the impeller 11.

  The diffuser 13 a converts kinetic energy (dynamic pressure) imparted to the compressed air into pressure energy (static pressure) by decelerating the flow velocity of the compressed air discharged from the discharge port 11 b of the impeller 11. The compressed air whose velocity is reduced when passing through the diffuser 13a flows into the spiral chamber 13c in communication with the diffuser 13a. The working fluid that has flowed into the spiral chamber 13 c is discharged to a discharge pipe (not shown).

  The partition plate 14 is a plate-like member provided on the upstream side of the flow direction of the air than the intake port 11 a and having a predetermined length in the axis X direction. As shown in FIG. 2, the partition plate 14 is comprised by four partition plates 14a, 14b, 14c, and 14d. The four partition plates 14a, 14b, 14c and 14d are radially arranged about the axis X. The partition plate 14 is devised to function as an impact absorbing material that absorbs the impact caused by the collision of all or part of the air guide cylinder 12. The partition plate 14 also supports the silencer casing 15 a of the silencer 15 and also functions as a flow straightening plate for straightening the air flowing in the silencer 15.

  As shown in FIG. 3, in the partition plate 14 b, the cross section along the axis X is a rectangle that is long in the axis X direction. Although only the partition plate 14b is illustrated in FIG. 3, the other partition plates 14a, 14c, and 14d also have the same cross-sectional shape.

  The partition plate 14 is made of a metal member manufactured by rolling. As this metal member, for example, a rolled steel material which is an Fe-C based alloy which contains iron as a main component and a slight amount (about 0.2%) of carbon is used. Although various materials can be used if it is a rolled steel material, it is preferable to use a rolled steel material for general structure (JIS G 3101; ASTM A 283) called SS400.

  The metal material by rolling has a composition suitable for a rolling process, and retains ductility leading to fracture after large plastic deformation. On the other hand, the metal material by casting consists of a composition suitable for a casting process, and the elongation to failure is smaller than the metal material by rolling. Thus, the metal material by rolling has a greater elongation to failure than the metal material by casting, that is, the ductility is high. Therefore, the rolled metal material has the property of higher fracture strength to impact than the cast metal material.

For example, tensile strength at normal temperature is about 400 to 500 N / mm ² for both ductile cast iron and SS400. On the other hand, while the elongation at break is about 10% of the ductile cast iron material, the S400 material retains 20% or more. Therefore, the SS400 material has higher ductility than the ductile cast iron material.

  In the centrifugal compressor 10 of the present embodiment, when all or a part of the blade 11 d of the impeller 11 is broken or dropped and scattered in the radial direction, it collides with the air guiding cylinder 12. The flow path 11e of the centrifugal compressor 10 is a flow path which is gradually inclined from the direction of the axis X from the intake port 11a toward the discharge port 11b. Therefore, an impact force in the radial direction and an impact force in the direction of the axis X are applied to the air guide cylinder 12. The impact force in the direction of the axis X is an impact force that causes the air guide cylinder 12 to fly away from the scroll portion 13. Therefore, the air guide cylinder 12 made of a metal member manufactured by casting is damaged and falls off from the mounting position. there is a possibility.

  When all or a part of the air guide cylinder 12 falls out of the mounting position and scatters toward the silencer 15, the air guide cylinder 12 collides with the partition plate 14 disposed inside the silencer 15. Therefore, the partition plate 14 made of a metal member by rolling retains large plastic deformation ductility until failure, and therefore absorbs kinetic energy of impact by plastic deformation when an impact load is generated. Thereby, scattering of all or part of the air guide cylinder 12 can be stopped. That is, by intentionally deforming and breaking the partition plate 14 to absorb an impact, the air guide cylinder 12 is scattered to the outside of the turbocharger 100 or an impact is given to other places to form a gap (opening). Is suppressing the problem that occurs.

  The plate thickness of the partition plate 14 of the present embodiment is in the range of 4 mm to 9 mm. Moreover, it is more preferable to set it as 5 mm or more and 7 mm or less, and it is preferable to set board thickness to 6 mm especially. If the rigidity of the partition plate 14 is too low, the impact load of all or part of the air guide cylinder 12 broken and scattered can not be sufficiently absorbed even if the partition plate 14 is greatly deformed, all or the air guide cylinder 12 A part is scattered to the outside of the turbocharger 100.

On the other hand, when the rigidity of the partition plate 14 is too high, the deformation of the partition plate 14 with respect to the impact load of all or part of the scattered air guide cylinder 12 decreases. Then, the partition plate 14 can not absorb the impact load, and the impact load propagates to other places, generating a gap (opening).
The inventors conducted experiments while changing the plate thickness of the partition plate 14, and the air guide cylinder 12 was not scattered to the outside, and a gap (opening) was not generated at other places. Since we have obtained the knowledge that the range is 9 mm or less, the plate thickness in this range is used.

  The silencer 15 shown in FIG. 1 is a device for reducing the level of noise generated in the centrifugal compressor 10. As shown in FIG. 1, the silencer 15 is provided with a silencer casing 15a. The silencer casing 15 a defines a flow path 15 b for guiding the air flowing in from the direction shown by the arrow in FIG. 1 (the direction orthogonal to the axis X) to the inlet 11 a of the air guiding cylinder 12. A silencer material 15e is disposed around the flow passage 15b so as to surround the flow passage 15b. A part of the noise generated in the centrifugal compressor 10 is absorbed by the sound deadening material 15e, and the noise level is reduced.

  As shown in FIG. 1, the silencer casing 15a accommodates the partition plate 14 inside. The end of the partition plate 14 is connected to the silencer casing 15a. Therefore, the partition plate 14 also functions as a support member for supporting the silencer casing 15a.

Next, the structure of the fastening position at which the silencer casing 15a and the scroll casing 13b are fastened will be described.
As described above, when all or a part of the air guide cylinder 12 drops out of the mounting position and scatters, all or a part of the air guide cylinder 12 collides with the partition plate 14. In the foregoing, it has been described that the partition plate 14 made of a rolled steel material absorbs and restrains kinetic energy of impact by plastic deformation when impact load is generated. Hereinafter, a structure for absorbing kinetic energy of impact other than the partition plate 14 will be described.

  As shown in FIG. 4, the flange portion 13d provided at the end of the scroll casing 13b on the silencer 15 side and the flange portion 15c provided at the end of the silencer casing 15a on the scroll casing 13b side are shown in FIG. The fastening bolt 40 (first fastening bolt) is fastened at the fastening position (first fastening position) shown.

Although only one fastening position is shown in FIG. 4, a plurality of fastening positions are provided at regular intervals in the circumferential direction around the axis X. The flange portion 13 d and the flange portion 15 c are fastened by the fastening bolt 40 at the plurality of fastening positions.
It is preferable to use a chromium molybdenum steel having a carbon content of 0.33 to 0.38%, which is called SCM 435, as the fastening bolt 40. The SCM 435 is excellent in that it has high strength and a large amount of elongation until breakage when a tensile load is applied.

  The flange portion 15 c is provided with a fastening hole 15 d extending along the axis X. Moreover, the fastening hole 13e extended along the axis line X is provided in the flange part 13d. Internal threads are formed on the inner peripheral surfaces of these fastening holes 15d and 13e. On the other hand, on the outer peripheral surface of the shaft 40b of the fastening bolt 40 extending along the axis X, a male screw is formed on the entire surface from the vicinity of the boundary between the head 40a and the shaft 40b to the vicinity of the tip of the shaft 40b. ing.

  A tensile load is generated on the fastening bolt 40 by equalizing the deformation at each location on the outer peripheral surface of the shaft portion 40b, and the stress is locally concentrated on the fastening bolt 40 even when plastic deformation is performed until the amount of extension increases Because it is difficult to break, it is preferable because it does not break up to a large elongation.

  The flange portion 13 d and the flange portion 15 c are cylindrical in shape and have a predetermined length and a cylindrical shape having an inner diameter d 1 smaller than the diameter d 2 of the head portion 40 a of the fastening bolt 40. It is fastened in the state inserted in the axial part 40b. In this state, the external thread formed on the shaft portion 40b of the fastening bolt 40 and the internal thread formed on the inner circumferential surfaces of the fastening holes 15d and 13e are in a meshed state.

The spacer 50 is made of a metal member manufactured by rolling. As this metal member, for example, a rolled steel material which is an Fe-C based alloy which contains iron as a main component and a slight amount (about 0.2%) of carbon is used. Although various materials can be used if it is a rolled steel material, it is preferable to use a rolled steel material for general structure (JIS G 3101; ASTM A 283) called SS400.
Since the rolled metal material retains ductility leading to failure after large plastic deformation, it has characteristics of higher fracture strength to impact than cast metal.

  As shown in FIG. 4, the air guide cylinder 12 and the scroll casing 13 b are fastened by a fastening bolt 42 inserted into a through hole provided in the flange portion 12 a of the air guide cylinder 12. Although only one fastening position is shown in FIG. 4, a plurality of fastening positions are provided at regular intervals in the circumferential direction around the axis X. The air guide cylinder 12 and the scroll casing 13 b are fastened by the fastening bolt 42 at the fastening positions of the plurality of places.

In the above description, it has been described that the kinetic energy of the impact is absorbed and stopped by the plastic deformation of the partition plate 14, but here a structure capable of absorbing the kinetic energy of the impact by the fastening bolt 40 and the spacer 50 other than the partition plate 14 Describe.
As described above, when all or a part of the air guide cylinder 12 drops out of the mounting position and scatters, all or a part of the air guide cylinder 12 collides with the partition plate 14. Due to this collision, an impact in a direction away from the scroll casing 13b is applied to the silencer casing 15a. This impact acts on the fastening position of the fastening bolt 40, the flange portion 15c and the flange portion 13d.

  The reason why the spacer 50 is inserted into the shaft portion 40b of the fastening bolt 40 as shown in FIG. 4 is to lengthen the length of the fastening bolt 40 in the direction of the axis X to secure a large amount of extension. is there. The predetermined length of the spacer 50 is at least longer than the diameter of the shaft portion 40b of the fastening bolt 40, and the length is set so as not to hinder the fastening operation. By increasing the amount of extension, it is possible to prevent the fastening bolt 40 from breaking, and by the extension of the fastening bolt 40, all or a part of the air guiding cylinder 12 drops out from the mounting position and scatters and collides Can absorb the kinetic energy of impact.

  Further, as shown in FIG. 4, the reason for providing the spacer 50 is to make the spacer 50 made of rolled steel having ductility absorb the kinetic energy of impact. Due to an impact acting on the fastening position of the fastening bolt 40 and the flange portion 15 c, the length of the spacer 50 disposed between the head 40 a of the fastening bolt 40 and the flange portion 15 c shrinks in the direction of the axis X. Since the spacer 50 made of rolled steel retains ductility leading to fracture after large plastic deformation, it can absorb the kinetic energy due to the above-mentioned impact by contracting along the direction of the axis X.

Next, the structure of the fastening position for fastening the scroll casing 13b and the bearing stand 20 will be described.
As shown in FIG. 1, the bearing stand 20 of the present embodiment includes a flange portion 20 a that supports the scroll portion 13 and a bearing portion 20 b that supports the rotor shaft 30.

As shown in FIG. 5, the flange 13f provided at the end of the scroll casing 13b on the bearing stand 20 side and the flange 20a provided at the end of the bearing stand 20 on the scroll casing 13b side are as shown in FIG. The fastening bolt 41 (second fastening bolt) is fastened at the fastening position (second fastening position) shown in FIG.
It is preferable to use a chromium molybdenum steel having a carbon content of 0.33 to 0.38% called SCM 435 as the fastening bolt 41. SCM 435 is excellent in that it has high strength and a large amount of elongation.

  The flange portion 13 f is provided with a fastening hole 13 g extending along the axis X. Moreover, the fastening hole 20c extended along the axis line X is provided in the flange part 20a. Internal threads are formed on the inner peripheral surfaces of these fastening holes 13g and 20c. On the other hand, on the outer peripheral surface of the shaft portion 41b of the fastening bolt 41 extending along the axis X, a male screw is formed on the entire surface from the head portion 41a to the tip portion.

  The flange portion 13 f and the flange portion 20 a insert the cylindrical spacer 51 (second spacer member) having an inner diameter d 3 smaller than the diameter d 4 of the head portion 41 a of the fastening bolt 41 into the shaft portion 41 b of the fastening bolt 41 It is concluded in the state. In this state, the external thread formed on the shaft portion 41b of the fastening bolt 41 and the internal thread formed on the inner peripheral surfaces of the fastening holes 13g and 20c are engaged with each other.

The spacer 51 is made of a metal member manufactured by rolling. As this metal member, for example, a rolled steel material which is an Fe-C based alloy which contains iron as a main component and a slight amount (about 0.2%) of carbon is used. Although various materials can be used if it is a rolled steel material, it is preferable to use a rolled steel material for general structure (JIS G 3101; ASTM A 283) called SS400.
Since the rolled metal material retains ductility leading to failure after large plastic deformation, it has characteristics of higher fracture strength to impact than cast metal.

  As described above, when all or part of the air guide cylinder 12 drops out of the mounting position and scatters, all or part of the air guide cylinder 12 collides with the partition plate 14. This collision causes an impact in the direction in which the scroll casing 13 b is separated from the bearing stand 20. This impact acts on the fastening position of the fastening bolt 41, the flange portion 13f and the flange portion 20a.

  The reason why the spacer 51 is inserted into the shaft portion 41b of the fastening bolt 41 as shown in FIG. 5 is to lengthen the length of the fastening bolt 41 in the direction of the axis X to secure a large amount of extension. is there. By increasing the amount of extension, it is possible to prevent the fastening bolt 41 from breaking, and by extension of the fastening bolt 41, all or a part of the air guiding cylinder 12 drops out from the mounting position and scatters and collides Can absorb the kinetic energy of impact.

  Further, as shown in FIG. 5, the reason for providing the spacer 51 is to make the spacer 51 made of rolled steel having ductility absorb the kinetic energy of impact. Due to an impact acting on the fastening position of the fastening bolt 41 and the flange portion 13f, the length of the spacer 51 disposed between the head portion 41a of the fastening bolt 41 and the flange portion 13f shrinks in the direction of the axis X. Since the spacer 51 made of rolled steel retains ductility leading to fracture after large plastic deformation, it can absorb the kinetic energy due to the above-described impact by contracting along the direction of the axis X.

Next, the clamp member 60 attached to the scroll casing 13 b and the outer peripheral edge portion of the bearing stand 20 will be described. The vicinity of the fastening position of the flange portion 13f of the scroll casing 13b and the flange portion 20a of the bearing stand 20 is as shown in FIG. 6 is a view of the outer peripheral edge of the flange portion 13f of the scroll casing 13b and the flange portion 20a from the P direction shown in FIG.
As shown in FIG. 6, in the circumferential direction around the axis X, a plurality of clamp members 60 are attached between a plurality of fastening positions (second fastening positions) by the fastening bolts 41.

  As shown in FIG. 7, the clamp member 60 has a recess 60a surrounding the outer peripheral edge of the flange portion 20a and the outer peripheral edge of the flange portion 13f of the scroll casing 13b from the outer peripheral side. In addition, the clamp member 60 has a through hole 60b that opens in the recess 60a and extends along the axis X direction.

  As shown in FIG. 7, the flange portion 20 a has a fastening hole 20 d extending in the direction of the axis X. Although only one fastening hole 20 d is shown in FIG. 7, the fastening holes 20 d are provided at a plurality of locations at equal intervals along the circumferential direction around the axis X. An internal thread is formed on the inner peripheral surface of the fastening hole 20d. On the other hand, a male screw is formed on the outer peripheral surface of the shaft portion of the fastening bolt 43 (third fastening bolt) inserted into the through hole 60b and the fastening hole 20d. The flange portion 20a and the clamp member 60 are fastened by the engagement of the male screw of the fastening bolt 43 and the female screw of the fastening hole 20d.

  With the clamp member 60 fastened to the flange portion 20a, a predetermined gap 60c is provided between the end face 13i in the axial line X direction of the scroll casing 13b and the end face 60e in the axial line X direction of the recess 60a. . The width along the axis X of the gap 60c is d5.

Further, the flange portion 20a connects the contact surface 20e in contact with the scroll casing 13b, the end surface 20f forming the flow passage 13h (second flow passage) through which the compressed air flows, and the step connecting the contact surface 20e and the end surface 20f And a unit 20g. As shown in FIG. 7, the end face 20f is disposed closer to the flow path 13h than the contact surface 20e.
The width d6 in the direction of the axis X of the step 20g is wider than the width d5 of the gap 60c.

  As described above, when the air guide cylinder 12 drops out of the mounting position, the air guide cylinder 12 collides with the partition plate 14. Due to this collision, an impact force is applied in the direction in which the scroll casing 13 b is separated from the bearing stand 20. This impact force acts on the fastening position of the fastening bolt 41, the flange portion 13f and the flange portion 20a.

  As shown in FIG. 7, the reason why the predetermined gap 60c is provided is that the fastening bolt 41 is broken because the impact in the direction of the axis X due to the scattering of all or part of the impeller 11 is broken and the scroll casing 13b When the bearing member 20 is separated from the bearing stand 20, the clamp member 60 absorbs the impact of the separated scroll casing 13b.

  When the predetermined gap 60c is not provided, the fastening force in the vicinity of the clamp member 60 is increased, and the fastening bolt 41 becomes difficult to break. In this case, although breakage of the fastening bolt 41 can be prevented, a load is applied to another portion (for example, the scroll casing 13b), and there is a possibility that the portion to which the load is applied may be broken.

When the fastening bolt 41 is broken and the scroll casing 13b is separated from the bearing stand 20, the state shown in FIG. 7 is changed to the state shown in FIG.
In the state shown in FIG. 8, the end face 13i in the direction of the axis X of the scroll casing 13b is in contact with the end face 60e in the direction of the axis X of the recess 60a. In this state, a gap 60d having a width of d5 in the direction of the axis X is formed in the portion of the contact surface 20e. If the gap 60d communicates with the flow path 13h and a gap (opening) is generated, there is a possibility that a broken part or the like of the blade 11d from the flow path 13h may be scattered to the outside.
In the present embodiment, as shown in FIG. 8, the width d6 in the direction of the axis X of the step 20g is wider than the width d5 of the gap 60d. Therefore, the problem that a gap (opening) such that the gap 60d communicates with the flow path 13h and the damaged member passes is prevented.

  In the present embodiment, the gap 60c is intentionally provided between the end face 13i in the direction of the axis X of the scroll casing 13b and the end face 60e in the direction of the axis X of the recess 60a. It is preventing. In addition, when the fastening bolt 41 is broken, the clamp member 60 absorbs an impact caused by the scroll casing 13 b moving away from the bearing stand 20.

Next, a method of manufacturing the centrifugal compressor according to the present embodiment will be described.
The manufacturing method of the centrifugal compressor 10 of this embodiment manufactures the centrifugal compressor 10 by the following processes.
In the first step, the impeller 11 which compresses the air flowing in from the inlet 11 a and discharges it from the outlet 11 b is attached to the rotor shaft 30.
In the second step, the air guide cylinder 12 is attached so as to accommodate the impeller 11, and the air flowing from the intake port 11a along the axis X direction of the rotor shaft 30 is guided in the direction inclined from the axis X direction. A flow path leading to the discharge port 11 b is formed.

In the third step, the scroll portion 13 into which the compressed air discharged from the discharge port 11 b flows is disposed on the outer peripheral side in the radial direction orthogonal to the axis X direction with respect to the air guide cylinder 12.
In the fourth step, a plurality of partition plates 14 having a plate thickness of 4 mm or more and 9 mm or less are provided upstream of the intake port 11 a in the air flow direction and have a predetermined length in the axis X direction. Arrange radially around X.
The centrifugal compressor 10 of the present embodiment is manufactured by the above steps.

The operation and effect of the centrifugal compressor 10 provided in the turbocharger 100 of the present embodiment described above will be described.
According to the centrifugal compressor 10 provided in the turbocharger 100 of the present embodiment, when all or part of the impeller 11 breaks or drops off, all or part of the impeller 11 scatters in the radial direction, and It collides with the guide cylinder 12.

  The air guide cylinder 12 forms a flow passage 11 e which guides the air flowing in from the intake port 11 a along the axis X direction of the rotor shaft 30 in a direction inclined from the axis X direction and guides the air to the discharge port 11 b. When all or a part of the radially scattered impellers 11 collide with the air guide cylinder 12, a radial impact is applied to the air guide cylinder 12. Similarly, when all or part of the impeller 11 scattered in the direction of the axis X collides with the air guiding cylinder 12, an impact in the direction of the axis X is applied to the air guiding cylinder 12. Since the impact in the direction of the axis X is an impact that scatters all or part of the air guide cylinder 12 in the direction away from the scroll portion 13, all or part of the air guide cylinder 12 may fall out of the mounting position .

  According to the centrifugal compressor 10 of the present embodiment, a plurality of partition plates 14 having a predetermined length in the axis X direction are arranged radially about the axis X on the upstream side of the flow direction of air than the intake port 11a. It is done. Therefore, all or part of the scattered impeller 11 or all or part of the air guide cylinder 12 scattered in the direction away from the scroll portion 13 due to the impact of the impeller 11 collides with the plurality of partition plates 14 .

  The plurality of partition plates 14 are rolled steel materials having a plate thickness of 4 mm or more and 9 mm or less. Therefore, when all or a part of the air guide cylinder 12 collides, it plastically deforms appropriately and absorbs energy due to the collision. Thereby, a gap is generated in a part of the centrifugal compressor 10 by scattering of all or a part of the air guide cylinder 12, and a defect that all or a part of the impeller 11 scatters to the outside from the gap is suppressed. Can.

  According to the centrifugal compressor 10 of the present embodiment, when all or part of the air guide cylinder 12 scattered in the direction away from the scroll portion 13 collides with the silencer casing 15a accommodating the partition plate 14, the silencer casing 15a is used as the scroll casing Impact is applied in the direction away from the This impact is absorbed by contraction of the spacer 50 disposed between the head 40 a of the fastening bolt 40 and the silencer casing 15 a. Thus, the problem of breakage of the fastening bolt 40 is suppressed by absorbing the impact in the axial direction using the spacer 50 that is fastened in a state of being inserted into the fastening bolt 40. Therefore, a gap is generated in a part of the centrifugal compressor 10 due to the scattering of all or a part of the air guide cylinder 12, and it is possible to suppress the problem that the impeller 11 is scattered all or part to the outside through the gap.

  In the centrifugal compressor 10 of the present embodiment, the fastening bolt 40 includes an external thread formed on the outer peripheral surface of the shaft portion 40 b from the head portion 40 a to the tip end portion. By doing this, the above-mentioned problems can be obtained by using the fastening bolt 40 that increases the energy absorption of impact by making the deformation at each location on the outer peripheral surface of the shaft portion 40b from the head portion 40a to the tip end uniform. Can be suppressed.

  According to the centrifugal compressor 10 of the present embodiment, when all or part of the air guide cylinder 12 scattered in the direction away from the scroll portion 13 collides with the silencer casing 15a accommodating the partition plate 14, the scroll casing 13b is supported by the bearing base An impact in the direction of pulling away from the flange portion 20a of 20 is applied. This impact is absorbed by contraction of the spacer 51 disposed between the head 41 a of the fastening bolt 41 and the scroll casing 13 b. As described above, by using the spacer 51 that is fastened in a state of being inserted into the fastening bolt 41, a problem in which the fastening bolt 41 is broken by absorbing an impact in the direction of the axis X is suppressed. Therefore, a gap is generated in a part of the centrifugal compressor 10 due to the scattering of all or a part of the air guide cylinder 12, and it is possible to suppress the problem that the impeller 11 is scattered all or part to the outside through the gap.

  In the centrifugal compressor 10 of the present embodiment, the fastening bolt 41 includes an external thread formed on the outer peripheral surface of the shaft portion 40b from the head portion 41a to the tip end portion. By doing this, the above-mentioned problems can be obtained by using the fastening bolt 41 that increases the energy absorption of impact by equalizing the deformation at each portion of the outer peripheral surface of the shaft portion 40b from the head portion 41a to the tip end portion. Can be suppressed.

  The centrifugal compressor 10 according to the present embodiment has a recess 60a that surrounds the outer peripheral edge of the flange portion 20a and the outer peripheral edge of the scroll casing 13b from the outer peripheral side, and opens in the recess 60a and extends along the axis X direction. A plurality of clamp members 60 having through holes 60 b are provided. Further, the flange portion 20a has a plurality of fastening holes 20d extending in the direction of the axis X in the circumferential direction around the axis X. The flange portion 20a and the clamp member 60 are fastened by the fastening bolt 43 inserted into the through hole 60b and the fastening hole 20d. Further, a predetermined gap 60c is provided between the end face 13i in the direction of the axis X of the scroll casing 13b and the end face 60e in the direction of the axis X of the recess 60a.

  By doing so, even when the plurality of fastening bolts 41 are broken and the flange portion 20a of the bearing stand 20 and the scroll casing 13b are separated, the end surface 13i in the direction of the axis X of the scroll casing 13b is , Contact with the end face 60e in the direction of the axis X of the recess 60a. The impact due to this contact is absorbed by the plurality of clamping members 60 mounted circumferentially around the axis X. Accordingly, it is possible to suppress a problem that a gap is generated in a part of the centrifugal compressor 10 due to the scattering of the air guide cylinder 12, and all or a part of the impeller 11 damaged from the gap scatters to the outside.

  In the present embodiment, the flange portion 20a is fastened by the clamp member 60 and the fastening bolt 43, and is predetermined between the end face 13i in the axis X direction of the scroll casing 13b and the end face 60e in the axis X direction of the recess 60a. A gap 60c is provided. The flange portion 20a forms a contact surface 20e in contact with the scroll casing 13b, and an end surface 20f of the flange portion 20a which is disposed on the flow passage 13h side with respect to the contact surface 20e, while forming a flow passage 13h through which the compressed air flows. And a step 20g for connecting the

  By doing this, the plurality of fastening bolts 41 are broken and the flange portion 20a of the bearing stand 20 and the scroll casing 13b are separated, and the end surface 13i in the direction of the axis X of the scroll casing 13b is the axis X in the recess 60a. In the case where the end face 60e of the contact is made, the opening between the flange 20a and the scroll casing 13b is suppressed by the presence of the step 20g. Furthermore, since the width d6 in the direction of the axis X of the step 20g is larger than the width d5 of the predetermined gap 60d, no communication gap is generated, and the opening can be more reliably suppressed.

Other Embodiments
In the above description, the rotor shaft 30 to which the impeller 11 of the centrifugal compressor 10 is connected is rotated about the axis X by a turbine (not shown) rotated by the exhaust gas discharged from the marine diesel engine. However, it may be another aspect. For example, the rotor shaft 30 may be rotated by another power source such as a motor connected to the rotor shaft 30.

  In the above description, although the partition plate 14 radially arranges four sheets at intervals of 90 degrees centering on the axis line X, another aspect may be sufficient. For example, an arbitrary number of sheets may be disposed, such as an aspect in which six sheets are radially disposed at an interval of 60 degrees around the axis X, or an aspect in which eight sheets are disposed at an interval of 45 degrees.

  In the above description, the clamp member 60 is fastened to the flange portion 20a of the bearing stand 20, but may be in another mode. For example, the clamp member 60 may be fastened to the flange portion 13f of the scroll casing 13b. In this case, the flange portion 13f of the scroll casing 13b has a plurality of fastening holes extending in the direction of the axis X in the circumferential direction around the axis X. Then, by fastening the fastening bolts 43 in the plurality of fastening holes, the clamp member 60 is fastened to the flange portion 13f of the scroll casing 13b. Further, in this case, the gap 60c described above is provided between the end face in the axial line X direction of the flange portion 20a of the bearing stand 20 and the end face in the axial line X direction of the recess of the clamp member 60.

Reference Signs List 10 centrifugal compressor 11 impeller 11a intake 11b discharge 11d blade 11e flow path 12 air guide cylinder (guide cylinder)
13 scroll part 13b scroll casing 13d flange part 13f flange part 13h flow path (second flow path)
13i end face 14 partition plate 15 silencer 15a silencer casing 15b flow path (first flow path)
15c Flange portion 20 Bearing base 20a Flange portion 20e Contact surface 20f End surface 20g Stepped portion 30 Rotor shaft 40 Fastening bolt (first fastening bolt)
41 Fastening bolt (Second fastening bolt; Flange fastening bolt)
43 Fastening bolt (3rd fastening bolt; clamp member fastening bolt)
50 spacer (first spacer member)
51 Spacer (second spacer member)
60 clamp member 60a recess 60b through hole 60c gap 60d gap 60e end face 100 supercharger

Claims (4)

An impeller attached to the rotor shaft and compressing fluid flowing in from the intake port and discharging the fluid from the discharge port;
A guide cylinder that accommodates the impeller;
A scroll portion having a scroll casing which is disposed on the outer peripheral side of the guide cylinder and which forms a vortex chamber into which the compressed fluid discharged from the discharge port flows.
A bearing base having a bearing portion for supporting the rotor shaft and a flange portion for supporting the scroll portion;
A plurality of flange portion fastening bolts that fasten the flange portion and the scroll casing at a plurality of fastening positions around the axis of the rotor shaft, and extend in the axial direction;
A plurality of clamp members having a recess surrounding the outer peripheral edge of the flange portion and the outer peripheral edge of the scroll casing from the outer peripheral side, and a plurality of through holes opened in the recess and extending along the axial direction; Equipped with
Any one of the flange portion or the scroll casing has a plurality of fastening holes extending in the axial direction in the circumferential direction around the axis,
Any one of the flange portion or the scroll casing and the clamp member are fastened by a clamp member fastening bolt inserted into the through hole and the fastening hole,
A centrifugal compressor characterized in that a predetermined gap is provided between the other axial end face of the flange portion or the scroll casing and the axial end face of the recess. The flange portion has the fastening hole and is fastened by the clamp member and the clamp member fastening bolt,
A predetermined gap is provided between the end face in the axial direction of the scroll casing and the end face in the axial direction of the recess,
The flange portion is connected to the contact surface in contact with the scroll casing and an end face of said flange portion which compressed fluid is disposed in front Symbol passage side than the contact surface to form a that channel to distribution The centrifugal compressor according to claim 1, comprising a step.   The centrifugal compressor according to claim 2, wherein the axial width of the stepped portion is wider than the width of the predetermined gap. The centrifugal compressor according to any one of claims 1 to 3,
And a turbine rotated about the axis by exhaust gas discharged from an internal combustion engine and coupled to the rotor shaft.

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