U.S. patent application number 16/784389 was filed with the patent office on 2021-04-01 for centrifugal compressor.
The applicant listed for this patent is MITSUBISHI HEAVY INDUSTRIES, LTD.. Invention is credited to Hiroshi SHIMIZU, Nobuyori YAGI, Shin YANAGISAWA.
Application Number | 20210095691 16/784389 |
Document ID | / |
Family ID | 1000004656786 |
Filed Date | 2021-04-01 |
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United States Patent
Application |
20210095691 |
Kind Code |
A1 |
YANAGISAWA; Shin ; et
al. |
April 1, 2021 |
CENTRIFUGAL COMPRESSOR
Abstract
A centrifugal compressor includes a passage forming member being
arranged in a rear side of an impeller fixed to a tip side of a
rotor shaft, and forming a passage, together with a scroll member,
and a casing member disposed adjacent to an opposite side of the
passage forming member from the impeller along an axial direction.
The passage forming member has a first protrusion, and the casing
member has a second protrusion. The first protrusion and the second
protrusion are fixed to each other by a bolt member inserted from
an outside in a radial direction toward an inside in the radial
direction.
Inventors: |
YANAGISAWA; Shin; (Tokyo,
JP) ; YAGI; Nobuyori; (Tokyo, JP) ; SHIMIZU;
Hiroshi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MITSUBISHI HEAVY INDUSTRIES, LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
1000004656786 |
Appl. No.: |
16/784389 |
Filed: |
February 7, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 29/42 20130101;
F04D 29/624 20130101 |
International
Class: |
F04D 29/42 20060101
F04D029/42; F04D 29/62 20060101 F04D029/62 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 26, 2019 |
JP |
2019-175395 |
Claims
1. A centrifugal compressor comprising: a rotor shaft rotatably
supported by a bearing; an impeller fixed to the rotor shaft in a
tip side with respect to the bearing; a passage forming member
arranged in a rear side of the impeller, the passage forming member
forming, together with a scroll member forming a scroll passage
outside the impeller in a radial direction, a passage communicating
with the scroll passage; and a casing member disposed adjacent to
an opposite side of the passage forming member to the impeller
along an axial direction, wherein the passage forming member has a
first protrusion formed to protrude toward the casing member, the
casing member has a second protrusion formed to protrude toward the
passage forming member, and the first protrusion and the second
protrusion are fixed to each other by a bolt member inserted from
an outside in the radial direction to an inside in the radial
direction.
2. The centrifugal compressor according to claim 1, wherein a
plurality of the bolt members are disposed along a circumferential
direction of the rotor shaft.
3. The centrifugal compressor according to claim 1, wherein the
first protrusion and the second protrusion are fixed to each other
by a pin member inserted along the radial direction.
4. The centrifugal compressor according to claim 1, wherein a
reinforcing rib is formed along the radial direction, over both a
radially outer surface of the second protrusion and a surface of
the casing member.
5. The centrifugal compressor according to claim 1, wherein the
first protrusion and the second protrusion are engaged with each
other via a spline.
6. The centrifugal compressor according to claim 1, wherein the
first protrusion and the second protrusion are engaged with each
other via an inlay structure.
7. The centrifugal compressor according to claim 1, wherein the
passage forming member has a sealing member configured to seal an
internal space accommodating the impeller from an outside, and to
rotatably support the rotor shaft.
8. The centrifugal compressor according to claim 7, wherein the
casing member has a bearing configured to rotatably support the
rotor shaft inside the sealing member in the axial direction.
9. The centrifugal compressor according to claim 1, wherein the
casing member accommodates a speed-increasing gear mechanism
provided with the rotor shaft.
10. A centrifugal compressor comprising: a rotor shaft rotatably
supported by a bearing; an impeller fixed to the rotor shaft in a
tip side with respect to the bearing; a passage forming member
arranged in a rear side of the impeller, the passage forming member
forming, together with a scroll member forming a scroll passage
outside the impeller in a radial direction, a passage communicating
with the scroll passage; and a casing member disposed adjacent to
an opposite side of the passage forming member to the impeller
along an axial direction, wherein the passage forming member has a
first protrusion formed to protrude toward the casing member, the
casing member has a second protrusion formed to protrude toward the
passage forming member, the first protrusion and the second
protrusion are fixed to each other by a bolt member inserted from
an outside in the radial direction to an inside in the radial
direction, and the first protrusion is arranged inside the second
protrusion in the radial direction.
11. The centrifugal compressor according to claim 10, wherein a
plurality of the bolt members are disposed along a circumferential
direction of the rotor shaft.
12. The centrifugal compressor according to claim 10, wherein the
first protrusion and the second protrusion are fixed to each other
by a pin member inserted along the radial direction.
13. The centrifugal compressor according to claim 10, wherein a
reinforcing rib is formed along the radial direction, over both a
radially outer surface of the second protrusion and a surface of
the casing member.
14. The centrifugal compressor according to claim 10, wherein the
first protrusion and the second protrusion are engaged with each
other via a spline.
15. The centrifugal compressor according to claim 10, wherein the
first protrusion and the second protrusion are engaged with each
other via an inlay structure.
16. The centrifugal compressor according to claim 10, wherein the
passage forming member has a sealing member configured to seal an
internal space accommodating the impeller from an outside, and to
rotatably support the rotor shaft.
17. The centrifugal compressor according to claim 16, wherein the
casing member has a bearing configured to rotatably support the
rotor shaft inside the sealing member in the axial direction.
18. The centrifugal compressor according to claim 10, wherein the
casing member accommodates a speed-increasing gear mechanism
provided with the rotor shaft.
Description
TECHNICAL FIELD
[0001] This disclosure relates to a centrifugal compressor.
BACKGROUND
[0002] A centrifugal compressor is known as a rotating machine,
which is capable of compressing fluid by use of centrifugal force.
Such a centrifugal compressor rotates an impeller attached to a
rotor shaft to generate compressed fluid. The rotor shaft is
rotatably supported by a bearing, and the impeller is fixed to at
least one end side of the rotor shaft.
[0003] As for a rotor shaft having a cantilever structurer, an
impeller is fixed to the rotor shaft in the tip side with respect
to the position supported by a bearing, and the diameter of the
impeller is larger than the diameter of the rotor shaft. Therefore,
it is important to suppress the shaft vibration from occurring
during rotation, and to prevent the impeller fixed to the rotor
shaft from contacting with a peripheral member. In an example,
Patent Document 1 discloses the configuration advantageous in
suppressing shaft vibration, in which a nut for fixing an impeller
to a rotor shaft is arranged inside the impeller so that the center
of gravity of the rotor is shifted to a bearing.
CITATION LIST
Patent Literature
[0004] Patent Document 1: JP2011-52580A
SUMMARY
[0005] A downsized rotor is advantageous in suppressing the shaft
vibration from occurring and in preventing the impeller from
contacting with a peripheral component in the description above.
Although, in Patent Document 1 described above, a nut is arranged
inside an impeller so as to provide a shorter rotor, resulting in
contributing to the suppression of the shaft vibration, there is
room for further improvement.
[0006] At least one aspect of the present disclosure has been
proposed in the light of the above-described circumstances. The
present disclosure is to provide a centrifugal compressor capable
of suppressing the rotor vibration from occurring in the rotor
shaft during driving, and preventing the impeller fixed to the
rotor shaft from contacting with a peripheral component.
[0007] A centrifugal compressor according to one aspect of the
present disclosure and capable of coping with the above includes: a
rotor shaft rotatably supported by a bearing; an impeller fixed to
the rotor shaft in a tip side with respect to the bearing; a
passage forming member being arranged in a rear side of the
impeller, and forming a passage communicating with a scroll
passage, together with a scroll member forming the scroll passage
outside the impeller in a radial direction; and a casing member
disposed adjacent to an opposite side of the passage forming member
from the impeller along an axial direction. In the centrifugal
compressor, the passage forming member has a first protrusion
formed to protrude toward the casing member, the casing member has
a second protrusion formed to protrude toward the passage forming
member, and the first protrusion and the second protrusion are
fixed to each other by a bolt member inserted from an outside in
the radial direction to an inside in the radial direction.
[0008] At least one aspect of the present disclosure enables
suppressing the vibration from occurring in the rotor shaft during
driving, and further preventing the impeller fixed to the rotor
shaft from contacting with a peripheral member.
BRIEF DESCRIPTION OF DRAWINGS
[0009] FIG. 1 is a perspective view illustrating a schematic
configuration of a centrifugal compressor according to one aspect
of the present disclosure.
[0010] FIG. 2 is a cross-sectional configuration diagram of a
vicinity of a turbo blower according to one aspect of the present
disclosure.
[0011] FIG. 3 is a cross-sectional view at an A-A line shown in
FIG. 2.
[0012] FIG. 4 is a cross-sectional view at a B-B line shown in FIG.
3.
[0013] FIG. 5 shows a modification of FIG. 3.
[0014] FIG. 6 shows another modification of FIG. 3.
[0015] FIG. 7 is a cross-sectional view at a D-D line shown in FIG.
6.
[0016] FIG. 8 shows another modification of FIG. 3.
[0017] FIG. 9 shows another modification of FIG. 4.
[0018] FIG. 10 is a cross-sectional configuration diagram of a
vicinity of a turbo blower according to the reference art.
DETAILED DESCRIPTION
[0019] Some embodiments of the present invention will now be
described below with reference to the drawings. However, the scope
of the present invention is not limited to the embodiments
described below. It is intended that sizes, materials, shapes,
relative positions and the like of components described in the
embodiments below are merely examples, and are not for limitation
of the scope of the present invention.
[0020] FIG. 1 is a perspective view illustrating a schematic
configuration of a centrifugal compressor 1 according to one aspect
of the present disclosure. The centrifugal compressor 1 is a geared
compressor (integrally geared compressor) in which a
speed-increasing gear mechanism 2 speeds up power and transmits the
power to a rotor 4 so as to compress fluid. The speed-increasing
gear mechanism 2 has a main driving shaft 6 which accepts power
from a power source (not shown), and a main driving gear 8
connected to the main driving shaft 6. The rotor 4 includes a
driven gear 10 engaged with the main driving gear 8, a rotor shaft
12 connected to the driven gear 10, and an impeller 14A and an
impeller 14B respectively provided at the tips of the rotor shaft
12.
[0021] When power is input from a power source to the
speed-increasing gear mechanism 2 via the main driving shaft 6, the
main driving gear 8 is rotated together with the main driving shaft
6. The rotation rotates the rotor 4 via the driven gear 10 engaged
with the main driving gear 8. When the rotor 4 is rotated, the
impellers 14A, 14B compress fluid by using the centrifugal force
generated by the rotation of the rotor shaft 12.
[0022] It is noted that, in the description below, the extending
direction of a rotation axis C of the rotor shaft 12 is called an
axial direction; the direction of the circumference around the
rotation axis C is called a circumferential direction; and the
direction of the diameter of the circumference is called a radial
direction. Moreover, the side close to the rotation axis C with
respect to the radial direction is called an inside in the radial
direction, and the side far from the rotation axis C with respect
to the radial direction is called an outside in the radial
direction.
[0023] The centrifugal compressor 1 has a gear casing 16 configured
to accommodate the speed-increasing gear mechanism 2, and a turbo
blower 18A and a turbo blower 18B respectively including the
impellers 14A, 14B. The turbo blowers 18A, 18B are arranged
respectively on the both sides in the axial direction with respect
to the gear casing 16, so as to correspond to the impellers 14A,
14B.
[0024] The turbo blower 18A has an inlet passage 19 for taking in
the fluid to be compressed from an upstream passage, and an outlet
passage 15 for discharging the fluid after compression to the
outside. The inlet passage 19 is communicated with an inlet pipe
not shown and the outlet passage 15 is communicated with an outlet
pipe not shown. As will be described below with reference to FIG. 2
and FIG. 10, the turbo blower 18A has, outside the impeller 14A in
the radial direction, a discharge scroll 24 which forms the outlet
passage 15 and which extends long in the radial direction to the
outside of the gear casing 16.
[0025] The turbo blower 18B has the same configuration as the
configuration of the turbo blower 18A described above, except that
the position and orientation to be arranged are different. In the
following description, the configuration of the turbo blower 18A is
mainly described. Unless otherwise stated, the configuration of the
turbo blower 18B is the same.
Reference Art
[0026] The internal configuration of the centrifugal compressor 1
is next described specifically. The reference art serving as a
prior art is described first. FIG. 10 is a cross-sectional
configuration diagram of the vicinity of the turbo blower 18A
according to the reference art.
[0027] The turbo blower 18A includes an impeller casing body 20,
and a passage forming member 22, together with the impeller casing
body 20, forming the outer casing of the turbo blower 18A. The
impeller 14A fixed to the tip of the rotor shaft 12 extending along
the rotation axis C is accommodated in an internal space S defined
by the impeller casing body 20 and the passage forming member 22.
The impeller casing body 20 mainly surrounds the impeller 14A from
the tip side (from the outside in the axial direction), and
accommodates the discharge scroll 24. The passage forming member 22
is arranged in the rear side (inside in the axial direction) of the
impeller 14A, and forms, together with the impeller casing body 20,
a communication passage R communicating the internal space S and
the discharge scroll 24.
[0028] The passage forming member 22 is fixed to the impeller
casing body 20 outside the gear casing 16 in the radial direction,
by a first bolt member 23 inserted along the axial direction. The
first bolt member 23 is inserted into a first hole part 25 formed
from the passage forming member 22 over to the impeller casing body
20, to fix the passage forming member 22 and the impeller casing
body 20 to each other.
[0029] At least one set of the first bolt member 23 and the first
hole part 25 is provided along the circumferential direction of the
rotation axis C. In FIG. 10, a plurality of sets of the first bolt
members 23 and the first hole parts 25 are provided, thereby
improving the rigidity of the passage forming member 22 and the
impeller casing body 20 fixed to each other.
[0030] The gear casing 16 accommodating the speed-increasing gear
mechanism 2 is disposed on the opposite side from the impeller 14A
along the axial direction with respect to the passage forming
member 22. The gear casing 16 includes a gear casing body 16a, and
a flange portion 16b which is disposed in the side of the passage
forming member 22 with respect to the gear casing body 16a, and
which faces the passage forming member 22 so as to be perpendicular
to the rotation axis C. The flange portion 16b is fixed to the
passage forming member 22 by a second bolt member 29 inserted along
the axial direction.
[0031] The second bolt member 29 is inserted into a second hole
part 30 formed from the flange portion 16b (gear casing 16) over to
the passage forming member 22, to fix the passage forming member 22
and the flange portion 16b (gear casing 16) to each other. At least
one set of such fixing structure including the second bolt member
29 and the second hole part 30 is provided along the
circumferential direction of the rotation axis C. In the example
shown in FIG. 10, a plurality of sets of the fixing structure
including the second bolt members 29 and the second hole parts 30
are provided at equal intervals along the circumferential direction
of the rotation axis C, to improve the rigidity.
[0032] The flange portion 16b has a disk shape substantially
perpendicular to the rotation axis C, and includes an opening 31
having a substantially circular shape including the rotation axis C
inside in the radial direction. In the opening 31, a sealing member
27 is arranged so as to rotatably support the rotor shaft 12 inside
the impeller 14A in the axial direction, and to seal the internal
space S from the outside. The flange portion 16b may be configured
to be dividable into a plurality of pieces, whereby the sealing
member 27 may be configured detachably.
[0033] The gear casing body 16a has a bearing 26 on the wall
surface defining the outer casing of the turbo blower 18A. The
bearing 26 rotatably supports the rotor shaft 12 inside the sealing
member 27 in the axial direction. That is, the rotor shaft 12 is
rotatably supported by the sealing member 27 of the flange portion
16b and by the bearing 26 of the gear casing body 16a, and the
sealing member 27 and the bearing 26 are arranged respectively
coaxially with the rotation axis C.
[0034] When the centrifugal compressor 1 is assembled, the second
bolt member 29 shall be inserted into the second hole part 30
without any physical interference of the second bolt member 29 at
the time of insertion. As for a gap M disposed along the rotation
axis C between the flange portion 16b and the gear casing body 16a,
such insertion requires the gap M to be ensured longer than the
length in the axial direction of the second bolt member 29. The gap
M as described above is required to be ensured by designing the
rotor shaft 12 to be large in length due to the convenience of the
assembly. The rotor shaft 12 designed large in length degrades the
rotor build (in an example, a parameter in designing specified by
D/L.sup.2 becomes smaller, when a diameter and a length in the
axial direction of the rotor shaft are denoted respectively by D
and L). This may increase the risk of the shaft vibration occurring
in the rotor 4 and/or the contact of the impeller 14A with a
peripheral member. Several aspects to be described below are
capable of suitably coping with the above.
[0035] It is noted that, in the aspects to be described below, the
configurations corresponding to those in the reference art
described above are denoted by the common reference signs, and the
duplicate description will be appropriately omitted unless
otherwise specified.
Embodiment
[0036] FIG. 2 is a cross-sectional configuration diagram of the
vicinity of the turbo blower 18A according to one aspect of the
present disclosure. FIG. 3 is a cross-sectional view at an A-A line
shown in FIG. 2. FIG. 4 is a cross-sectional view at a B-B line
shown in FIG. 3.
[0037] The passage forming member 22 has, on the side thereof
facing the gear casing 16, a first protrusion 32 formed to protrude
toward the gear casing 16. The gear casing 16 has, on the side
thereof facing the passage forming member 22, a second protrusion
34 formed to protrude toward the passage forming member 22. The
first protrusion 32 is arranged inside the second protrusion 34 in
the radial direction, and the first protrusion 32 and the second
protrusion 34 are arranged respectively coaxially with the rotation
axis C. The first protrusion 32 and the second protrusion 34 are
configured so that the outside face in the radial direction of the
first protrusion 32 and the inside face in the radial direction of
the second protrusion 34 are contacted with each other.
[0038] In the above-described arrangement where the first
protrusion 32 is arranged inside the second protrusion 34 in the
radial direction, the thermal expansion in the first protrusion 32
is greater than that in the second protrusion 34 when the turbo
blower 18A is increased in temperature during the operation of the
centrifugal compressor 1. As a result, the gap between the first
protrusion 32 and the second protrusion 34 is decreased, thereby
providing good sealing property.
[0039] The first protrusion 32 and the second protrusion 34 in
contact with each other are fixed by a bolt member 36 inserted into
a hole part 35 formed along the radial direction. The configuration
allows the bolt member 36 to be inserted from the outside in the
radial direction at the time of assembly. This eliminates the need
for ensuring the gap M allowing the second bolt member 29 to be
inserted as in the reference art described above by referring to
FIG. 10. Accordingly, the rotor shaft 12 is enabled to be shortened
in the axial direction (the corresponding gap can be reduced
compared to the gap M shown in FIG. 10), thereby enabling to
effectively suppress the risk of the shaft vibration occurring in
the rotor 4 and/or the contact of the impeller 14A with a
peripheral member.
[0040] The hole part 35 into which the bolt member 36 is inserted
at the time of assembly is formed so as to be continuous from the
second protrusion 34 over to the first protrusion 32 when the first
protrusion 32 and the second protrusion 34 are in a predetermined
positional relation shown in FIG. 3. In the example shown in FIG.
3, the hole part 35 penetrates through the second protrusion 34
located outside, from the outside in the radial direction toward
the inside in the radial direction, and up to the inside of the
first protrusion 32 located inside, from the outside in the radial
direction. In such positional relation, the bolt member 36 is
inserted into the hole part 35, thereby enabling to fix the
relative positional relation between the first protrusion 32 and
the second protrusion 34. That is, the hole part 35 and the bolt
member 36 have the function of relative positioning of the first
protrusion 32 and the second protrusion 34.
[0041] At least one set of such components of the hole part 35 and
the bolt member 36 is provided along the circumferential direction
around the rotation axis C. In the present embodiment, a plurality
of sets of the hole parts 35 and the bolt members 36 are provided
at equal intervals along the circumferential direction around the
rotation axis C (when the upper direction in FIG. 3 is set as 0
degree, the sets of such components are respectively provided at
the positions of 0 degree, 90 degrees, 180 degrees, and 270
degrees).
[0042] FIG. 5 shows a modification of FIG. 3. In the present
modification, the first protrusion 32 and the second protrusion 34
in contact with each other include not only the fixing structure
including the hole parts 35 and the bolt members 36 described
above, but also additional fixing structure in which a pin member
38 is inserted into a pin hole part 37 along the radial direction.
This configuration enables further improving the rigidity at the
time when the first protrusion 32 and the second protrusion 34 are
fixed to each other (in other words, the rigidity of the first
protrusion 32 and the second protrusion 34 fixed to each other by
the pin member 38 is improved in this way, thereby also enabling to
provide sufficient strength even with fewer sets of the hole parts
35 and the bolt members 36 described above.
[0043] At least one set of the pin hole part 37 and the pin member
38 is provided along the circumferential direction around the
rotation axis C. In the present embodiment, a plurality of sets of
the pin hole parts 37 and the pin members 38 are provided at equal
intervals along the circumferential direction around the rotation
axis C (when the upper direction in FIG. 5 is set as 0 degree, the
sets of the pin hole parts 37 and the pin members 38 are
respectively arranged at the positions of 45 degrees, 135 degrees,
225 degrees, and 315 degrees).
[0044] FIG. 6 shows another modification of FIG. 3. FIG. 7 is a
cross-sectional view at a D-D line shown in FIG. 6. In the present
modification, at least one of the first protrusion 32 and the
second protrusion 34 has a reinforcing rib 40. In FIG. 7, the
reinforcing rib 40 is formed along the radial direction over both a
radially outer surface 34a of the second protrusion 34 located
outside the first protrusion 32 in the radial direction and a
surface 34b of the gear casing 16 where the second protrusion 34 is
disposed. This configuration enables to further improve the
rigidity of the gear casing 16 where the second protrusion 34 is
disposed.
[0045] FIG. 8 shows another modification of FIG. 3. In the present
modification, the first protrusion 32 of the passage forming member
22 and the second protrusion 34 of the gear casing 16 are engaged
with each other via a spline 42. The structure of connecting the
first protrusion 32 and the second protrusion 34 enables to more
effectively improve the rigidity in the circumferential
direction.
[0046] FIG. 9 shows another modification of FIG. 4. In the present
modification, the first protrusion 32 and the second protrusion 34
are engaged with each other in an inlay structure 44. In the
example shown in FIG. 9, the passage forming member 22 has, outside
the first protrusion 32 in the radial direction, a concave portion
44a allowing a convex portion 44b disposed at the tip of the second
protrusion 34 to be engaged with. The adoption of the inlay
structure 44 described above enables to accurately position the
first protrusion 32 and the second protrusion 34 along the radial
direction. The accurate positioning enables to coaxially and
accurately align the sealing member 27 supported by the passage
forming member 22 and the bearing 26 supported by the gear casing
16, thereby enabling to more effectively prevent the shaft
vibration from occurring in the rotor 4 and/or the impeller 14A
from contacting with a peripheral member.
[0047] Moreover, a known component is available as needed, instead
of a component in the embodiment described above within the scope
not deviating from the gist of the present disclosure. Some of the
components described above may be combined as needed.
[0048] The contents described in the above respective embodiments
are grasped, for example, as follows.
[0049] (1) A centrifugal compressor (for example, the centrifugal
compressor 1 in the above described embodiments) according to one
aspect of the present disclosure includes: a rotor shaft (for
example, the rotor shaft 12 in the above described embodiments)
rotatably supported by a bearing (for example, the bearing 26 in
the above described embodiments); an impeller (for example, the
impeller 14A or 14B in the above described embodiments) fixed to
the rotor shaft in a tip side with respect to the bearing; a
passage forming member (for example, the passage forming member 22
in the above described embodiments) being arranged in a rear side
of the impeller, and forming a passage communicating with a scroll
passage, together with a scroll member (for example, the impeller
casing body 20 in the above described embodiments) forming the
scroll passage outside the impeller in a radial direction; and a
casing member (for example, the gear casing 16 in the above
described embodiments) disposed adjacent to an opposite side of the
passage forming member from the impeller along an axial direction.
In the centrifugal compressor, the passage forming member has a
first protrusion (for example, the first protrusion 32 in the above
described embodiments) formed to protrude toward the casing member,
the casing member has a second protrusion (for example, the second
protrusion 34 in the above described embodiments) formed to
protrude toward the passage forming member, and the first
protrusion and the second protrusion are fixed to each other by a
bolt member (for example, the bolt member 36 in the above described
embodiments) inserted from an outside in the radial direction
toward an inside in the radial direction.
[0050] According to the aspect of (1), the first protrusion of the
passage forming member and the second protrusion of the casing
member are fixed to each other by the bolt member. The bolt member
is allowed to be inserted in the radial direction at the time of
assembly, and this configuration eliminates the need for ensuring
the gap allowing the bolt member to be inserted, between the casing
member and the passage forming member. Accordingly, the rotor shaft
is configured short in the axial direction, thereby enabling to
effectively suppress the risk of the shaft vibration occurring in
the rotor and/or the contact of the impeller with a peripheral
member.
[0051] (2) In another aspect of the centrifugal compressor
according to the aspect of (1), the first protrusion is arranged
inside the second protrusion in the radial direction.
[0052] According to the aspect of (2), the first protrusion of the
passage forming member and the second protrusion of the casing
member under the state where the first protrusion is arranged
inside the second protrusion in the radial direction are fixed by
the bolt member. Accordingly, the thermal expansion in the first
protrusion is greater than that in the second protrusion when the
passage forming member is increased in temperature during the
operation of the centrifugal compressor. As a result, the gap
between the first protrusion and the second protrusion is
decreased, thereby providing good sealing property.
[0053] (3) In another aspect of the centrifugal compressor
according to the aspect of (1) or (2), a plurality of the bolt
members are arranged along a circumferential direction of the rotor
shaft.
[0054] According to the aspect of (3), the arrangement of the
plurality of bolt members along the circumferential direction of
the rotor shaft enables to effectively improve the rigidity of the
fixing structure of the first protrusion and the second protrusion
fixed by the bolt members.
[0055] (4) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (3), the first protrusion and
the second protrusion are fixed to each other by a pin member (for
example, the pin member 38 in the above described embodiment)
inserted along the radial direction.
[0056] According to the aspect of (4), the pin member in addition
to the bolt member fixes the first protrusion and the second
protrusion, thereby providing further higher rigidity. Such a
configuration additionally allowing the pin member to be inserted
along the radial direction contributes to shorten the length in the
axial direction of the rotor shaft, and thus enables to effectively
suppress the risk of the shaft vibration occurring in the rotor
and/or the contact of the impeller with a peripheral member. In
this case, since the pin member is able to improve the rigidity of
the first protrusion and the second protrusion fixed to each other,
the number of the bolt members is able to be reduced.
[0057] (5) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (4), a reinforcing rib (for
example, the reinforcing rib 40 in the above described embodiment)
is formed along the radial direction, over both a radially outer
surface of the second protrusion and a surface of the casing
member.
[0058] According to the aspect of (5), the rigidity of the casing
member provided with the second protrusion 34 is able to be
improved further.
[0059] (6) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (5), the first protrusion and
the second protrusion are engaged with each other via a spline (for
example, the spline 42 in the above described embodiment).
[0060] According to the aspect of (6), the first protrusion and the
second protrusion are engaged with each other via the spline,
thereby enabling to provide higher rigidity, and further enabling
to more effectively prevent the shaft vibration from occurring in
the rotor and/or the impeller from contacting with a peripheral
member.
[0061] (7) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (6), the first protrusion and
the second protrusion are engaged with each other via an inlay
structure (for example, the inlay structure 44 in the above
described embodiment).
[0062] According to the aspect of (7), the first protrusion and the
second protrusion are engaged with each other via the inlay
structure, thereby enabling to provide higher rigidity, and further
enabling to more effectively prevent the shaft vibration from
occurring in the rotor and/or the impeller from contacting with a
peripheral member.
[0063] (8) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (7), the passage forming
member has a sealing member (for example, the sealing member 27 in
the above described embodiments) configured to seal an internal
space accommodating the impeller from an outside, and to rotatably
support the rotor shaft.
[0064] According to the aspect of (8), the passage forming member
is provided with the sealing member configured to seal the space
accommodating the impeller from the outside. The sealing member
needs to be arranged coaxially and accurately with the rotor shaft
so as to rotatably support the rotor shaft. The bolt member
inserted along the radial direction fixes the casing member and the
passage forming member with high rigidity as described above,
thereby enabling to realize the coaxial arrangement of the sealing
member with high accuracy.
[0065] (9) In another aspect of the centrifugal compressor
according to the aspect of (8), the casing member has a bearing
(for example, the bearing 26 in the above described embodiments)
configured to rotatably support the rotor shaft inside the sealing
member in the axial direction.
[0066] According to the aspect of (9), the casing member is
provided with the bearing configured to rotatably support the rotor
shaft. The bearing needs to be arranged coaxially and accurately
with the rotor shaft so as to rotatably support the rotor shaft.
The bolt member inserted along the radial direction fixes the
casing member and the passage forming member with high rigidity as
described above, thereby enabling to realize the coaxial
arrangement of the bearing with high accuracy.
[0067] (10) In another aspect of the centrifugal compressor
according to any one aspect of (1) to (9), the casing member
accommodates a speed-increasing gear mechanism (for example, the
speed-increasing gear mechanism 2 in the above described
embodiments) provided with the rotor shaft.
[0068] According to the aspect of (10), a geared compressor in
which the casing member accommodates the speed-increasing gear
mechanism is capable of suppressing the vibration from occurring in
the rotor shaft during driving, and further capable of preventing
the impeller fixed to the rotor shaft from contacting with a
peripheral member.
* * * * *