DESCRIPTION
TITLE: TURBOCHARGER
TECHNICAL FIELD
5 [0001] This disclosure relates to a turbocharger.
BACKGROUND
[0002] Hitherto, as a technology of increasing the output of an engine, a method of
compressing intake air by a turbocharger and supplying the compressed intake air to the
10 engine (turbocharging) has been known and widely used in engines for automobiles and the
like. In general, the turbocharger includes a rotation shaft and a compressor impeller
provided on the rotation shaft on one end side thereof. By rotating the rotation shaft at high
speed by the exhaust energy of the exhaust gas and the driving force of a motor and the like,
the intake air is compressed by the compressor impeller provided on the rotation shaft on one
15 end side thereof.
[0003] The intake air compressed by the compressor impeller flows through a diffuser
flow path defined between a compressor housing and a bearing housing, thereby being
introduced to a scroll flow path formed in the outer peripheral portion of the compressor
housing.
20 [0004] In general, the radially outer portion of the compressor impeller is formed to have
a size substantially same or larger than that of the radially inner portion of the bearing housing,
and a large gap does not exist between the outer peripheral edge of the compressor impeller
and the inner peripheral wall surface of the bearing housing. Thus, there has not been a
problem in which the intake air compressed by the compressor impeller leaks into the bearing
25 housing through this gap to cause a large pressure loss, thereby decreasing the compression
efficiency.
Citation List
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Patent Literature
[0005]
Patent Document 1: JP2002-180841A
Patent Document 2: JP2008-223673A
5
SUMMARY
Technical Problem
[0006] As engines are increasingly downsized in recent years, demands for a compressor
impeller that is smaller than the related art are increasing. When a compressor impeller that
10 is smaller than the related art is considered to be employed, there is a problem in that, when
components such as a bearing housing, a thrust plate accommodated in the bearing housing,
and an insert component configured to fix the thrust plate are used in common for the relatedart
turbocharger, a large gap is formed between the outer peripheral edge of the compressor
impeller and the inner peripheral wall surface of the bearing housing, thereby decreasing the
15 compression efficiency.
[0007] When the radially inner portion of the bearing housing is downsized in accordance
with the radially outer portion of the small compressor impeller, there is a need to change the
shapes of the components such as the thrust plate and the insert component accommodated in
the bearing housing, thereby leading to an increase in costs.
20 When the radially outer portion of the compressor impeller is extended to fill the gap,
the moment of inertia of the compressor impeller increases, thereby degrading responsiveness.
[0008] In FIG. 1 and the like of Patent Document 1, a technology of preventing the
compression efficiency of a turbo compressor from decreasing as follows is disclosed.
Specifically, in a turbocharger (turbo compressor 3) in which a seal plate (denoted by 11) is
25 fixed to a bearing housing (bearing housing 7) by a fastening screw (denoted by 21) in a
diffuser flow path (diffuser D), an opening end portion of a counterbore (denoted by 20)
configured to support the fastening screw is occluded. However, the turbo compressor of
Patent Document 1 has a basic structure different from that of the turbocharger according to
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one embodiment of this invention described later in that the seal plate is fixed to the end
portion of the bearing housing by the fastening screw in the turbo compressor of Patent
Document 1.
[0009] In FIG. 2 and the like of Patent Document 2, a technology of preventing the
compression efficiency of a compressor impeller 5 from decreasing as follows is disclosed.
Specifically, in a turbocharger (turbocharger) in which a seal plate (denoted by 20) is fixed to
a bearing housing (denoted by 3) by a bolt (denoted by 21), an annular component (denoted
by 31) facing a diffuser portion (denoted by 27) is provided in order to occlude an opening
end portion of a hole portion (denoted by 37) configured to retain the head of the bolt.
10 However, the turbocharger of Patent Document 2 has a basic structure different from that of
the turbocharger according to one embodiment of this invention described later in that the seal
plate is fixed to the end portion of the bearing housing by the bolt in the turbocharger of
Patent Document 2.
[0010] According to at least one embodiment of this invention, this invention is provided
15 on the basis of the situation of the related-art the technology as above and has an object to
provide a turbocharger capable of enhancing the compression efficiency by filling a gap
formed between an outer peripheral edge of a compressor impeller and an inner peripheral
wall surface of a bearing housing through a simple structure.
20 Solution to Problem
[0011] (1) A turbocharger according to at least one embodiment of this invention
includes:
a rotation shaft;
a compressor impeller provided on one end side of the rotation shaft;
25 a compressor housing configured to accommodate the compressor impeller;
a bearing housing connected, at an end portion on one side thereof, to the compressor
housing, the bearing housing being configured to define, between the bearing housing and the
compressor housing, a diffuser flow path which extends along a direction orthogonal to an
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axis of the rotation shaft and through which intake air compressed by the compressor impeller
flows, the bearing housing including a protruding wall portion protruding from an inner
peripheral wall surface of the bearing housing;
a thrust plate accommodated in the bearing housing and configured to support the
5 rotation shaft in an axial direction;
an insert component accommodated in the bearing housing at a position closer to the
end portion of the bearing housing on one side thereof than a position of the thrust plate in the
axial direction of the rotation shaft, and configured to retain the thrust plate between the insert
component and the protruding wall portion;
10 a snap ring accommodated in the bearing housing and configured to be inserted in a first
circumferential groove formed in the inner peripheral wall surface of the bearing housing, to
thereby fix the insert component in a state in which the insert component is pressed against
the thrust plate; and
a diffuser component accommodated in the bearing housing and having a diffuser
15 surface that defines a part of the diffuser flow path extending along the direction orthogonal to
the axis of the rotation shaft between the inner peripheral wall surface of the end portion of
the bearing housing on one side thereof and an outer peripheral edge of the compressor
impeller.
[0012] The turbocharger according to item (1) includes the diffuser component
20 accommodated in the bearing housing. The diffuser component has the diffuser surface
extending along the direction orthogonal to the axis of the rotation shaft between the inner
peripheral wall surface of the end portion of the bearing housing on one side thereof and the
outer peripheral edge of the compressor impeller and configured to define a part of the
diffuser flow path. As a result, by filling a gap between the outer peripheral edge of the
25 compressor impeller and the inner peripheral wall surface of the end portion of the bearing
housing on one side thereof by the diffuser surface of the diffuser component described above,
the intake air flowing through the diffuser flow path can be prevented from flowing into the
gap and the compression efficiency of the turbocharger can be enhanced.
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[0013] Thus, for example, when the compressor impeller is downsized, the bearing
housing and the components accommodated in the bearing housing can be used in common
for the turbocharger of the related-art.
[0014] (2) In several embodiments, in the turbocharger according to item (1), the insert
component includes: an inner peripheral portion 5 including an inner peripheral-side wall
portion extending along the direction orthogonal to the axis of the rotation shaft; and an outer
peripheral portion including an outer peripheral-side wall portion extending along the
direction orthogonal to the axis of the rotation shaft at a position farther from the end portion
of the bearing housing on one side thereof than a position of the inner peripheral-side wall
10 portion, and a protruding portion protruding from the outer peripheral-side wall portion
toward the thrust plate. The snap ring is configured to be positioned on an outer peripheral
side of the inner peripheral portion of the insert component and come into abutment with the
outer peripheral-side wall portion of the insert component in a state in which the snap ring is
inserted in the first circumferential groove. The diffuser component is configured to be
15 positioned on an outer peripheral side of the inner peripheral portion of the insert component.
[0015] According to the embodiments described in item (2), in the insert component, the
outer peripheral-side wall portion of the outer peripheral portion is at a position farther from
the end portion of the bearing housing on one side thereof than a position of the inner
peripheral-side wall portion of the inner peripheral portion. As a result, a space is formed
20 between the inner peripheral portion on the outer peripheral side thereof and the inner
peripheral wall surface of the bearing housing. Thus, the insert component, the snap ring,
and the diffuser component can be compactly placed in the bearing housing by placing the
snap ring and the diffuser component in the space.
[0016] The snap ring is configured to come into abutment with the outer peripheral-side
25 wall portion of the insert component in a state in which the snap ring is inserted in the first
circumferential groove. As a result, the pressing force transmitted from the snap ring to the
insert component can be efficiently transmitted to the thrust plate via the protruding portion
protruding from the outer peripheral-side wall portion.
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[0017] (3) In several embodiments, in the turbocharger according to item (2), the diffuser
component includes: a plate-shaped diffuser portion having the diffuser surface; and a plateshaped
outer peripheral-side plate portion extending along the axial direction of the rotation
shaft from an outer peripheral end portion of the diffuser portion. The outer peripheral-side
plate portion is configured to come into abutment with an 5 inner peripheral wall surface of the
bearing housing along the axial direction of the rotation shaft.
[0018] According to the embodiments described in item (3), the outer peripheral-side
plate portion of the diffuser component is configured to come into abutment with an inner
peripheral wall surface of the bearing housing along the axial direction of the rotation shaft.
10 As a result, in the bearing housing, the accuracy of positioning the diffuser component in the
direction orthogonal to the axis of the rotation shaft can be enhanced.
[0019] (4) In several embodiments, in the turbocharger according to item (3), the insert
component includes a projecting portion protruding from an outer peripheral end portion of
the inner peripheral portion to an outer peripheral side. The diffuser component includes a
15 plate-shaped inner peripheral-side plate portion extending from an inner peripheral end
portion of the diffuser portion toward the inner peripheral portion of the insert component.
In a state in which the insert component and the diffuser component are accommodated in the
bearing housing, an inner peripheral end of the inner peripheral-side plate portion is
configured to be positioned farther from the end portion of the bearing housing on one side
20 thereof than the projecting portion in the axial direction of the rotation shaft, and positioned
closer to the rotation shaft than an outer peripheral end of the projecting portion in the
direction orthogonal to the axis of the rotation shaft.
[0020] According to the embodiments described in item (4), when the diffuser component
is about to fall out of the opening in the end portion of the bearing housing on one side thereof,
25 the inner peripheral-side plate portion of the diffuser component is caught by the projecting
portion of the insert component. As a result, the diffuser component can be prevented from
falling out.
[0021] (5) In several embodiments, in the turbocharger according to (3) or (4) described
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above, a radially outer portion of the diffuser component is formed to be larger than a radially
inner portion of the end portion of the bearing housing on one side thereof. The diffuser
component is press fitted in the bearing housing to be fixed in the bearing housing.
[0022] According to the embodiments described in item (5), the diffuser component can
be fixed in the bearing housing through a 5 simple structure in which the diffuser component is
simply press fitted in the bearing housing.
[0023] (6) In several embodiments, in the turbocharger according to any one of (3) to (5),
a radially inner portion of the diffuser component is formed to be smaller than a radially outer
portion of an outer peripheral end surface of the inner peripheral portion of the insert
10 component. The diffuser component is fitted with the outer peripheral end surface of the
inner peripheral portion of the insert component to be fixed in the bearing housing.
[0024] According to the embodiments described in item (6), the diffuser component can
be fixed in the bearing housing through a simple structure in which the outer peripheral end
surface of the inner peripheral portion of the insert component is simply fitted with the
15 diffuser component.
[0025] (7) In several embodiments, in the turbocharger according to item (3) or (4), the
inner peripheral wall surface of the bearing housing has a second circumferential groove
formed therein at a position closer to the end portion of the bearing housing on one side
thereof than a position of the first circumferential groove in the axial direction of the rotation
20 shaft. The diffuser component includes a plate-shaped insert plate portion extending from
the outer peripheral-side plate portion to an outer peripheral side. The insert plate portion is
configured to be inserted in the second circumferential groove.
[0026] According to the embodiments described in item (7), the diffuser component can
be fixed in the bearing housing through a simple structure in which the insert plate portion of
25 the diffuser component is simply inserted in the second circumferential groove. According
to the embodiment as above, the dimension tolerance of the diffuser component on the outer
peripheral side can be set to be loose.
[0027] (8) In several embodiments, in the turbocharger according to item (7), the second
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circumferential groove is formed over an entire periphery of the inner peripheral wall surface
of the bearing housing. The insert plate portion is configured to be inserted in the second
circumferential groove over the entire periphery of the inner peripheral wall surface of the
bearing housing.
[0028] According to the embodiments described in item 5 (8), the diffuser component can
be securely fixed in the bearing housing because the insert plate portion of the diffuser
component is inserted in the second circumferential groove over the entire periphery of the
inner peripheral wall surface of the bearing housing.
[0029] (9) In several embodiments, in the turbocharger according to item (7), the first
10 circumferential groove is formed over an entire periphery of the inner peripheral wall surface
of the bearing housing. The snap ring has a spaced section formed by spacing arc shaped
end portions from each other. The outer peripheral-side plate portion of the diffuser
component includes a first outer peripheral-side plate portion, and a second outer peripheralside
plate portion formed at a position different from the first outer peripheral-side plate
15 portion in a circumferential direction and having an extending length shorter than an
extending length of the first outer peripheral-side plate portion. The insert plate portion of
the diffuser component includes a first insert plate portion extending from the first outer
peripheral-side plate portion to the outer peripheral side, and a second insert plate portion
extending from the second outer peripheral-side plate portion to the outer peripheral side.
20 The second insert plate portion is configured to be inserted in the second circumferential
groove. The first insert plate portion is configured to be inserted in the first circumferential
groove at the spaced section of the snap ring inserted in the first circumferential groove.
[0030] According to the embodiments described in item (9), the snap ring has the spaced
section formed by separating the end portions of an arc shape from each other. The first
25 insert plate portion is configured to be inserted in the first circumferential groove at the
spaced section of the snap ring inserted in the first circumferential groove. In this way, the
part of the bearing housing to be processed can be kept at a minimum by effectively utilizing
the first circumferential groove formed for inserting the snap ring therein. The diffuser
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component can be securely fixed in the bearing housing by inserting the second insert plate
portion in the second circumferential groove in addition to inserting the first insert plate
portion in the first circumferential groove.
[0031] (10) In several embodiments, in the turbocharger according to item (9), when the
diffuser component is viewed from the axial 5 direction of the rotation shaft, the second insert
plate portion is formed at a position opposed to the first insert plate portion in the
circumferential direction.
[0032] According to the embodiments described in item (10), the first insert plate portion
and the second insert plate portion are formed at positions opposed to each other in the
10 circumferential direction. As a result, the diffuser component can be securely fixed by the
inside of the bearing housing because the diffuser component can be supported by two places
opposed to each other in the circumferential direction.
[0033] (11) In several embodiments, in the turbocharger according to item (9) or (10), the
diffuser component includes a plate-shaped cylindrical plate portion extending from an inner
15 peripheral end portion of the diffuser portion toward the insert component along the axial
direction of the rotation shaft. The insert component includes a projecting portion
protruding from an outer peripheral end surface of the inner peripheral portion to an outer
peripheral side, and at least one projecting portion is formed in the circumferential direction
or the projecting portion is formed in plurality at intervals in the circumferential direction. A
20 recessed portion or a slit, in which the projecting portion is inserted when the cylindrical plate
portion is fitted with the outer peripheral end portion of the inner peripheral portion of the
insert component, is formed in an inner peripheral surface of the cylindrical plate portion
along the axial direction of the rotation shaft.
[0034] According to the embodiments described in item (11), the cylindrical plate portion
25 of the diffuser component is fitted with the outer peripheral end surface of the inner peripheral
portion of the insert component 6 in addition to inserting the first insert plate portion in the
first circumferential groove and inserting the second insert plate portion in the second
circumferential groove. As a result, the diffuser component can be securely fixed by the
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inside of the bearing housing.
[0035] The recessed portion or the slit in which the projecting portion is inserted when
the cylindrical plate portion is fitted with the outer peripheral end surface of the inner
peripheral portion of the insert component is formed in the inner peripheral surface of the
cylindrical plate portion along the axial direction of 5 the rotation shaft. As a result, the
diffuser component can be easily positioned in the circumferential direction by inserting the
diffuser component in the bearing housing along the axial direction of the rotation shaft so
that the projecting portion is inserted in the recessed portion or the slit.
[0036] (12) In several embodiments, in the turbocharger according to item (2) or (3), the
10 diffuser component includes a plate-shaped horizontal plate portion extending from an inner
peripheral end portion of the diffuser portion toward the insert component along the axial
direction of the rotation shaft. The horizontal plate portion has a distal end on which a
bulged portion bulging more than other portions of the horizontal plate portion is formed.
The outer peripheral-side wall portion of the insert component has a fitting groove formed
15 therein, with which the distal end of the horizontal plate portion can be fitted.
[0037] According to the embodiments described in item (12), the diffuser component can
be fixed in the bearing housing through a simple structure in which the distal end of the
horizontal plate portion of the diffuser component is simply fitted with the fitting groove of
the insert component.
20 [0038] (13) In several embodiments, in the turbocharger according to any one of items (3)
to (12), the diffuser component is formed of a plate-shaped component formed by bending a
metallic plate.
[0039] According to the embodiments described in item (13), the diffuser component can
be formed by a simple method of simply bending a metallic plate. Furthermore, the surface
25 roughness of a metallic plate is greater than that of a casting and the like. As a result,
according to the embodiment as above, the pressure loss in the diffuser flow path can be
reduced because the diffuser portion defining the diffuser flow path is made of a metallic plate.
[0040] (14) In several embodiments, in the turbocharger according to item (2), a diffuser
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portion of the diffuser component has a screw hole formed therein, with which a screw
component can be threadedly engaged. The outer peripheral-side wall portion of the insert
component has a screw hole formed therein, with which the screw component can be
threadedly engaged. The diffuser component is fastened with the insert component by
threadedly engaging the screw component 5 with the screw hole in the diffuser component and
the screw hole in the insert component from the diffuser surface of the diffuser component.
[0041] According to the embodiments described in item (14), the diffuser component can
be fixed in the bearing housing through a simple structure in which the diffuser component is
simply threadedly engaged with the insert component by the screw component.
10 [0042] (15) In several embodiments, in the turbocharger according to item (2), a screw
groove having a predetermined length is formed in the inner peripheral wall surface of the
bearing housing from the end portion on one side of the bearing housing along the axial
direction of the rotation shaft. The diffuser component is formed to be an annular shape, and
a screw thread that can threadedly engage with the screw groove is formed in the outer
15 peripheral surface of the diffuser component.
[0043] According to the embodiments described in item (15), the diffuser component can
be fixed in the bearing housing through a simple structure in which the outer peripheral
surface of the diffuser component and the inner peripheral wall surface of the bearing housing
are simply threadedly engaged with each other.
20 [0044] According to at least one embodiment of this invention, the turbocharger capable
of enhancing the compression efficiency by filling the gap formed between the outer
peripheral edge of the compressor impeller and the inner peripheral wall surface of the
bearing housing through a simple structure can be provided. Thus, for example, when the
compressor impeller is downsized, the bearing housing and the components accommodated in
25 the bearing housing can be used in common for the turbocharger of the related-art.
BRIEF DESCRIPTION OF DRAWINGS
[0045] FIG. 1 is a sectional side view illustrating a cross section of a turbocharger
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according to one embodiment of this invention taken along the axial direction of a rotation
shaft.
FIG. 2A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
FIG. 2B is a view illustrating a diffuser component 5 in the turbocharger illustrated in FIG.
2A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
view of the diffuser component.
FIG. 3A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
10 FIG. 3B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
3A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
view of the diffuser component.
FIG. 4A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
15 FIG. 4B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
4A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
view of the diffuser component.
FIG. 4C is a view for describing the assembling state of an insert component, a snap ring,
and the diffuser component in the turbocharger illustrated in FIG. 4A.
20 FIG. 5A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
FIG. 5B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
5A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
view of the diffuser component.
25 FIG. 5C is a view for describing the assembling state of an insert component, a snap ring,
and the diffuser component in the turbocharger illustrated in FIG. 5A.
FIG. 6A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
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FIG. 6B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
6A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
view of the diffuser component.
FIG. 6C is a view for describing the assembling state of an insert component, a snap ring,
and the dif 5 fuser component in the turbocharger illustrated in FIG. 6A.
FIG. 7A is a sectional view of the main part of the turbocharger according to one
embodiment of this invention.
FIG. 7B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
7A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
10 view of the diffuser component.
FIG. 8A is a sectional view of the main part of a turbocharger according to one
embodiment of this invention.
FIG. 8B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
8A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
15 view of the diffuser component.
FIG. 9A is a sectional view of the main part a turbocharger according to one
embodiment of this invention.
FIG. 9B is a view illustrating a diffuser component in the turbocharger illustrated in FIG.
9A in which (a) is a sectional side view of the diffuser component and (b) is a perspective
20 view of the diffuser component.
FIG. 10 is an enlarged sectional side view illustrating an insert component according to
one embodiment of this invention.
DETAILED DESCRIPTION
25 [0046] Several embodiments of this invention are described below with reference to the
attached drawings. However, the dimensions, the materials, the shapes, the relative
arrangement, and the like of the components described as embodiments and illustrated in the
drawings are only examples and the scope of this invention is not intended to be limited
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thereto.
For example, expressions describing relative arrangements or absolute arrangements
such as "to a direction", "along a direction", "parallel", "orthogonal", "center", "concentric",
and "coaxial" not only precisely describe those arrangements, but also describe states
relatively changing depending on a tolerance or on an angle or 5 a distance allowing the same
function to be achieved.
For example, expressions indicating that elements are in the same state such as "same",
"equal", and "homogeneous" not only describe states that are precisely equal, but also
describe states in which a tolerance or a difference achieving the same function exists.
10 For example, expressions describing shapes such as a quadrangle and a cylinder not
only describe shapes such as a quadrangle and a cylinder in geometrically precise terms, but
also describe shapes including recessed portions, projecting portions, chamfered portions, and
the like within the range in which the same effect is achieved.
Expressions of "comprising", "including", or "having" a component are not exclusive
15 expressions excluding the existence of other components.
In the description below, the same configurations are sometimes denoted by the same
numerals to omit the detailed description thereof.
[0047] FIG. 1 is a sectional side view illustrating the cross section of a turbocharger
according to one embodiment of this invention taken along the axial direction of a rotation
20 shaft of the turbocharger.
The turbocharger according to one embodiment of this invention is not particularly
limited, but is, for example, a turbocharger mounted on an engine for an automobile.
As illustrated in FIG. 1, a turbocharger 100 of this embodiment includes three housings,
that is, a turbine housing 102 configured to accommodate a turbine impeller 103 provided on
25 a rotation shaft 2 on one end side thereof, a compressor housing 104 configured to
accommodate a compressor impeller 105 provided on the rotation shaft 2 on the other end
side thereof, and a bearing housing 106 configured to accommodate a radial bearing 110
configured to support the rotation shaft 2 in a rotatable manner and a thrust plate 4 configured
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to support the thrust force (axial force) of the rotation shaft 2.
[0048] A spiral-shaped turbine scroll flow path 113 is formed at an outer peripheral
portion of the turbine housing 102. The turbine impeller 103 is placed at a central part of the
turbine scroll flow path 113. The turbine impeller 103 includes a turbine hub 103A having a
truncated conical shape formed by cutting off a top portion of 5 a cone along a plane parallel to
the base thereof, and a plurality of turbine blades 103B provided to radially protrude from the
peripheral surface of the turbine hub 103A. The turbine hub 103A of the turbine impeller
103 is bonded to one end portion of the rotation shaft 2 by welding, for example. Exhaust
gas flowing through the turbine scroll flow path 113 and acting on the turbine impeller 103 is
10 discharged to the outside of the turbine housing 102 from an exhaust gas discharging flow
path 111 extending along the axial direction of the rotation shaft 2.
[0049] A spiral-shaped compressor scroll flow path 117 is formed at an outer peripheral
portion of the compressor housing 104. The compressor impeller 105 is placed at a central
part of the compressor scroll flow path 117. The compressor impeller 105 includes a
15 compressor hub 105A having a truncated conical shape formed by cutting off a top portion of
a cone along a plane parallel to the base thereof, and a plurality of compressor blades 105B
provided to radially protrude from the peripheral surface of the compressor hub 105A. An
insertion hole (not shown) to which the other end side of the rotation shaft 2 is inserted is
formed at a central part of the compressor hub 105A of the compressor impeller 105. The
20 compressor impeller 105 is fixed to the other end portion of the rotation shaft 2 by inserting
one end side of the rotation shaft 2 into the insertion hole and fastening a nut 116 from the tip
of the compressor hub 105A. Intake air flowing through an intake air introducing flow path
115 extending along the axial direction of the rotation shaft 2 and compressed by the
compressor impeller 105 is introduced to the compressor scroll flow path 117 via a diffuser
25 flow path 112 extending along the direction orthogonal to the axis of the rotation shaft 2, and
is supplied to an engine (not shown).
[0050] The bearing housing 106 is placed between the turbine housing 102 and the
compressor housing 104. The bearing housing 106 is connected, at an end portion on one
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side thereof, to the compressor housing 104, and connected, at an end portion on the other
side thereof, to the turbine housing 102. The diffuser flow path 112 described above is
defined between the bearing housing 106 and the compressor housing 104.
A protruding wall portion 106A protruding from an inner peripheral wall surface 106a
of the bearing housing 106 is formed in the 5 bearing housing 106. A lubricant oil introducing
path 118 configured to introduce lubricant oil to be supplied to the radial bearing 110 and the
thrust plate 4 described above is formed in the protruding wall portion 106A. The lubricant
oil introduced into the bearing housing 106 from the lubricant oil introducing path 118
lubricates the radial bearing 110 and the thrust plate 4 and is discharged to the outside of the
10 bearing housing 106 from a lubricant oil outlet 119 formed in a lower part of the bearing
housing 106.
[0051] FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, FIG. 7A, FIG. 8A, and FIG. 9A each
are a sectional view of the main part of a turbocharger according to one embodiment of this
invention. FIG. 2B, FIG. 3B, FIG. 4B, FIG. 5B, FIG. 6B, FIG. 7B, FIG. 8B, and FIG. 9B each
15 are a view illustrating each diffuser component of the turbochargers illustrated in FIG. 2A,
FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, FIG. 7A, FIG. 8A, and FIG. 9A in which (a) is a sectional
side view of the diffuser component and (b) is a perspective view of the diffuser component.
FIG. 4C is a view for describing the assembling state of an insert component, a snap ring, and
the diffuser component in the turbocharger illustrated in FIG. 4A. FIG. 5C is a view for
20 describing the assembling state of an insert component, a snap ring, and the diffuser
component in the turbocharger illustrated in FIG. 5A. FIG. 6C is a view for describing the
assembling state of an insert component, a snap ring, and the diffuser component in the
turbocharger illustrated in FIG. 6A.
[0052] As illustrated in FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, FIG. 7A, FIG. 8A,
25 and FIG. 9A, in the turbocharger 100 according to at least one embodiment of this invention,
at least an insert component 6, a snap ring 8, and a diffuser component 9 in addition to the
thrust plate 4 described above are accommodated in the bearing housing 106.
[0053] As described above, the thrust plate 4 is configured to support the rotation shaft 2
14-643PCT
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in the axial direction.
In the embodiment illustrated in the drawings, the thrust plate 4 is an annular plateshaped
component having an insertion hole 4A through which the rotation shaft 2 is inserted.
The thrust plate 4 is accommodated in the bearing housing 106 in a state in which one surface
4a of the thrust plate 4 is in abutment with 5 a side surface of the protruding wall portion 106A
of the bearing housing 106.
[0054] In the embodiment illustrated in the drawings, a first thrust collar 3A and a second
thrust collar 3B located at a position closer to an end portion of the bearing housing 106 on
one side thereof (the end portion on the side connected to the compressor housing 104) than a
10 position of the first thrust collar 3A are mounted on the rotation shaft 2. The first thrust
collar 3A and the second thrust collar 3B respectively have cylindrical collar main body
portions 3A1 and 3B1 and large-diameter portions 3A2 and 3B2 formed to have diameters
larger than those of the collar main body portions 3A1 and 3B1, and are mounted on the outer
periphery of the rotation shaft 2 so as to be rotatable with the rotation shaft 2. The collar
15 main body portion 3A1 of the first thrust collar 3A is inserted in the insertion hole 4A in the
thrust plate 4. The thrust plate 4 is accommodated in a recessed portion formed between the
large-diameter portion 3A2 of the first thrust collar 3A and the large-diameter portion 3B2 of
the second thrust collar 3B. The thrust plate 4 is configured to be in sliding contact with the
large-diameter portion 3A2 of the first thrust collar 3A and the large-diameter portion 3B2 of
20 the second thrust collar 3B to support the rotation shaft 2 in the axial direction.
[0055] The insert component 6 is accommodated in the bearing housing 106 at a position
closer to the end portion of the bearing housing 106 on one side thereof than a position of the
thrust plate 4 in the axial direction of the rotation shaft 2. The insert component 6 is
configured to retain the thrust plate 4 between the insert component 6 and the protruding wall
25 portion 106A of the bearing housing 106.
[0056] In the embodiment illustrated in the drawings, the insert component 6 includes an
annular plate-shaped component having an insertion hole 6C. The main body portion 3B1 of
the second thrust collar 3B mounted on the outer periphery of the rotation shaft 2 is inserted
14-643PCT
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in the insertion hole 6C. The radially outer portion of the insert component 6 has
substantially the same size as the radially inner portion of the bearing housing 106. The
outer peripheral surface of the insert component 6 is configured to come into abutment with
the inner peripheral wall surface 106a of the bearing housing 106, and the inner peripheral
surface of the insert component 6 is configured 5 to be in sliding contact with the outer
peripheral surface of the main body portion 3B1 of the second thrust collar 3B. An annular
seal groove is formed in the inner peripheral wall surface 106a of the bearing housing 106
positioned on the outer peripheral side of the insert component 6. An annular seal
component 7 such as an O ring is placed in the seal groove.
10 [0057] In the embodiment illustrated in the drawings, an oil deflector 5 is placed between
the thrust plate 4 and the insert component 6. The oil deflector 5 is a component configured
to prevent the lubricant oil supplied to the thrust plate 4 from leaking out to the compressor
impeller 105 side, and is an annular plate-shaped component made of a metallic plate, for
example. The oil deflector 5 is fixed in the bearing housing 106 by sandwiching a part of the
15 outer peripheral edge thereof between the thrust plate 4 and the insert component 6.
[0058] The snap ring 8 is inserted in a first circumferential groove 81 formed in the inner
peripheral wall surface 106a of the bearing housing 104, to thereby fix the insert component 6
in a state in which the insert component 6 is pressed against the thrust plate 4.
[0059] The diffuser component 9 has a diffuser surface 91a extending along the direction
20 orthogonal to the axis of the rotation shaft 2 between the inner peripheral wall surface 106a of
the end portion of the bearing housing 106 on one side thereof and an outer peripheral edge
105a of the compressor impeller 105. In the embodiment illustrated in the drawings, the
diffuser surface 91a is formed with the same width in the circumferential direction.
[0060] In the turbocharger 100 according to one embodiment of this invention configured
25 as above, a gap S between the outer peripheral edge 105a of the compressor impeller 105 and
the inner peripheral wall surface 106a of the end portion of the bearing housing 106 on one
side thereof is filled with the diffuser surface 91a of the diffuser component 9 described above,
and hence the intake air flowing through the diffuser flow path 112 can be prevented from
14-643PCT
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flowing into the gap S to enhance the compression efficiency of the turbocharger 100.
[0061] Specifically, as illustrated in FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A, FIG.
7A, FIG. 8A, and FIG. 9A, in the turbocharger 100 according to one embodiment of this
invention, the radially outer portion of the compressor impeller 105 is smaller than the
radially inner portion of the end portion of the bearing 5 housing 106 on one side thereof.
Thus, the gap S is formed between the inner peripheral wall surface 106a of the end portion of
the bearing housing 106 on one side thereof and the outer peripheral edge 105a of the
compressor impeller 105. In the embodiment illustrated in the drawings, the size of the gap
S is from 2% to 30% of an internal radius R of the end portion of the bearing housing 106 on
10 one side thereof. When the gap S as above is formed in a flow path surface defining the
diffuser flow path 112, the intake air flowing through the diffuser flow path 112 flows into the
gap S to cause a large pressure loss. Thus, the decrease in the compression efficiency of the
turbocharger 100 due to the intake air flowing into the gap S can be prevented by filling the
gap S with the diffuser surface 91a of the diffuser component 9 described above.
15 [0062] Thus, according to one embodiment of this invention as described above, for
example, when the compressor impeller 105 is downsized, the bearing housing and the
components accommodated in the bearing housing can be used in common for the
turbocharger of the related-art.
[0063] FIG. 10 is an enlarged sectional side view illustrating an insert component
20 according to one embodiment of this invention.
In several embodiments, as illustrated in FIG. 2A, FIG. 3A, FIG. 4A, FIG. 5A, FIG. 6A,
FIG. 7A, FIG. 8A, FIG. 9A, and the enlarged view of FIG. 10, the insert component 6 includes
an inner peripheral portion 6A including an inner peripheral-side wall portion 61 extending
along the direction orthogonal to the axis of the rotation shaft 2, and an outer peripheral
25 portion 6B including an outer peripheral-side wall portion 62 extending along the direction
orthogonal to the axis of the rotation shaft 2 at a position farther from the end portion of the
bearing housing 106 on one side thereof than a position of the inner peripheral-side wall
portion 61 and a protruding portion 63 protruding from the outer peripheral-side wall portion
14-643PCT
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62 toward the thrust plate 4. The snap ring 8 is configured to be positioned on the outer
peripheral side of the inner peripheral portion 6A of the insert component 6 and configured to
come into abutment with the outer peripheral-side wall portion 62 of the insert component 6
in a state in which the snap ring 8 is inserted in the first circumferential groove 81. The
diffuser component 9 is configured to be positioned 5 on the outer peripheral side of the inner
peripheral portion 6A of the insert component 6.
[0064] In the embodiment illustrated in the drawings, the protruding portion 63 of the
insert component 6 protrudes from an outer peripheral end portion of the outer peripheral-side
wall portion 62. An outer peripheral surface 63a of the protruding portion 63 is in abutment
10 with the inner peripheral wall surface 106a of the bearing housing 106. The distal end of the
protruding portion 63 is in abutment with an outer peripheral end portion of another surface
4b of the thrust plate 4. A step portion 63b configured to come into abutment with an outer
peripheral end portion of the oil deflector 5 is formed in the distal end of the protruding
portion 63.
15 [0065] In the embodiment illustrated in the drawings, the inner peripheral portion 61 of
the insert component 6 includes an extension portion 64 extending from an inner peripheral
end portion of the inner peripheral-side wall portion 61 toward the thrust plate 4 along the
axial direction of the rotation shaft 2. A connection portion 65 configured to connect the
inner peripheral portion 6A and the outer peripheral portion 6B to each other is formed
20 between the inner peripheral portion 6A and the outer peripheral portion 6B.
[0066] According to the embodiment as above, in the insert component 6, the outer
peripheral-side wall portion 62 of the outer peripheral portion 6B is at a position farther from
the end portion of the bearing housing 106 on one side thereof than a position of the inner
peripheral-side wall portion 61 of the inner peripheral portion 6A. Specifically, the outer
25 peripheral-side wall portion 62 is positioned closer to the thrust plate 4 than the inner
peripheral-side wall portion 61. As a result, a space is formed between the inner peripheral
portion 6A on the outer peripheral side thereof and the inner peripheral wall surface 106a of
the bearing housing 106. Thus, the insert component 6, the snap ring 8, and the diffuser
14-643PCT
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component 9 can be compactly placed in the bearing housing 106 by placing the snap ring 8
and the diffuser component 9 in the space.
[0067] The snap ring 8 is configured to come into abutment with the outer peripheral-side
wall portion 62 of the insert component 6 in a state in which the snap ring 8 is inserted in the
first circumferential groove 81. As a result, the 5 pressing force transmitted from the snap ring
8 to the insert component 6 can be efficiently transmitted to the thrust plate 4 via the
protruding portion 63 protruding from the outer peripheral-side wall portion 62.
[0068] In several embodiments, as illustrated in FIG. 2A, FIG. 2B, FIG. 3A, FIG. 3B, FIG.
4A, FIG. 4B, FIG. 4C, FIG. 5A, FIG. 5B, FIG. 5C, FIG. 6A, FIG. 6B, and FIG. 6C, the diffuser
10 component 9 includes a plate-shaped diffuser portion 91 having the diffuser surface 91a, and a
plate-shaped outer peripheral-side plate portion 92 extending from an outer peripheral end
portion of the diffuser portion 91 along the axial direction of the rotation shaft 2. The outer
peripheral-side plate portion 92 is configured to come into abutment with the inner peripheral
wall surface 106a of the bearing housing 106 along the axial direction of the rotation shaft 2.
15 [0069] According to the embodiment as above, the outer peripheral-side plate portion 92
of the diffuser component 9 is configured to come into abutment with the inner peripheral
wall surface 106a of the bearing housing 106 along the axial direction of the rotation shaft 2.
As a result, in the bearing housing 106, the accuracy of positioning the diffuser component 9
in the direction orthogonal to the axis of the rotation shaft 2 can be enhanced.
20 [0070] In several embodiments, as illustrated in FIG. 2A, FIG. 3B, FIG. 3A, and FIG. 3B,
the insert component 6 includes a projecting portion 66 protruding from an outer peripheral
end surface 61a of the inner peripheral portion 6A to the outer peripheral side. The diffuser
component 9 includes a plate-shaped inner peripheral-side plate portion 93 extending from an
inner peripheral end portion of the diffuser portion 91 toward the inner peripheral portion 6A
25 of the insert component 6. In a state in which the insert component 6 and the diffuser
component 9 are accommodated in the bearing housing 106, an inner peripheral end 93a of
the inner peripheral-side plate portion 93 is configured to be positioned farther from the end
portion of the bearing housing 106 on one side thereof than the projecting portion 66 in the
14-643PCT
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axial direction of the rotation shaft 2, and positioned closer to the rotation shaft 2 than an
outer peripheral end 66a of the projecting portion 66 in the direction orthogonal to the axis of
the rotation shaft 2.
[0071] In the embodiment illustrated in the drawings, the inner peripheral-side plate
portion 93 includes a horizontal portion 931 extending 5 from the inner peripheral end portion
of the diffuser portion 91 along the axial direction of the rotation shaft 2 and a vertical portion
932 extending from an end portion of the horizontal portion 931 along the direction
orthogonal to the axis of the rotation shaft 2. The projecting portion 66 forms an annular
shape continuously extending in the circumferential direction.
10 [0072] According to the embodiment as above, when the diffuser component 9 is about to
fall out of the opening in the end portion of the bearing housing 106 on one side thereof, the
inner peripheral-side plate portion 93 of the diffuser component 9 is caught by the projecting
portion 66 of the insert component 6. As a result, the diffuser component 9 can be prevented
from falling out.
15 [0073] In several embodiments, the radially outer portion of the diffuser component 9 is
formed to be larger than the radially inner portion of the end portion of the bearing housing
106 on one side thereof. As illustrated in FIG. 2A and FIG. 2B, the diffuser component 9 is
press fitted in the bearing housing 106, to thereby be fixed in the bearing housing 106.
[0074] In the embodiment illustrated in the drawings, the radially outer portion of the
20 diffuser component 9, specifically, the radially outer portion of the outer peripheral-side plate
portion 92 in a state before the diffuser component 9 is press fitted in the bearing housing 106
is formed to be slightly larger than the radially inner portion of the end portion of the bearing
housing 106 on one side thereof. By press fitting the diffuser component 9 in the bearing
housing 106 from the opening in the end portion of the bearing housing 106 on one side
25 thereof, the diffuser component 9 is fixed in the bearing housing 106.
[0075] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the diffuser component 9 is
simply press fitted in the bearing housing 106.
14-643PCT
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[0076] In several embodiments, the radially inner portion of the diffuser component 9 is
formed to be smaller than the radially outer portion of the outer peripheral end surface 61a of
the inner peripheral portion 6A of the insert component 6. As illustrated in FIG. 2A and FIG.
2B, the diffuser component 9 is fitted with the outer peripheral end surface 61a of the inner
peripheral portion 6A of the insert component 6, to 5 thereby be fixed in the bearing housing
106.
[0077] In the embodiment illustrated in the drawings, the radially inner portion of the
diffuser component 9, specifically, the radially inner portion of the inner peripheral-side plate
portion 93 in a state before the diffuser component 9 is fitted with the outer peripheral end
10 surface 61a of the inner peripheral portion 6A of the insert component 6 is formed to be
slightly smaller than the radially outer portion of the outer peripheral end surface 61a of the
inner peripheral portion 6A of the insert component 6. The diffuser component 9 is inserted
in the bearing housing 106 from the opening in the end portion of the bearing housing 106 on
one side thereof, and the inner peripheral-side plate portion 93 of the diffuser component 9 is
15 fitted with the outer peripheral end surface 61a of the inner peripheral portion 6A of the insert
component 6, to thereby fix the diffuser component 9 to the inside of the bearing housing 106.
[0078] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the diffuser component 9 is
simply fitted with the outer peripheral end surface 61a of the inner peripheral portion 6A of
20 the insert component 6.
[0079] In several embodiments, as illustrated in FIG. 2A, the diffuser component 9 is
configured to come into abutment, at the distal end of the outer peripheral-side plate portion
92, with the snap ring 8 inserted in the first circumferential groove 81.
[0080] In the embodiment illustrated in the drawings, the diffuser component 9 is
25 configured to be at a position suitable for the diffuser surface 91a of the diffuser portion 91 to
define the diffuser flow path 112 in a state in which the distal end of the outer peripheral-side
plate portion 92 is in abutment with the snap ring 8 inserted in the first circumferential groove
81.
14-643PCT
- 25 -
[0081] According to the embodiment as above, when the diffuser component 9 is inserted
in the bearing housing 106 from the opening in the end portion of the bearing housing 106 on
one side thereof, the diffuser component 9 can be easily positioned in the axial direction of the
rotation shaft 2.
[0082] In several embodiments, as illustrated in FIG. 5 3A and FIG. 3B, a second
circumferential groove 99 is formed in the inner peripheral wall surface 106a of the bearing
housing 106 at a position closer to the end portion of the bearing housing 106 on one side
thereof than a position of the first circumferential groove 81 in the axial direction of the
rotation shaft 2. The diffuser component 9 includes a plate-shaped insert plate portion 94
10 extending from the outer peripheral-side plate portion 92 to the outer peripheral side. The
insert plate portion 94 is configured to be inserted in the second circumferential groove 99.
[0083] In the embodiment illustrated in the drawings, the insert plate portion 94 extends
from the distal end of the outer peripheral-side plate portion 92 along the direction orthogonal
to the axis of the rotation shaft 2. The position of the insert plate portion 94 in the axial
15 direction of the rotation shaft 2 is closer to the end portion of the bearing housing 106 on one
side thereof than the vertical portion 932 of the inner peripheral-side plate portion 93.
[0084] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the insert plate portion 94 of the
diffuser component 9 is simply inserted in the second circumferential groove 99. According
20 to the embodiment as above, the dimension tolerance of the diffuser component 9 on the outer
peripheral side can be set to be loose.
[0085] In several embodiments, as illustrated in FIG. 3A and FIG. 3B, the second
circumferential groove 99 is formed over the entire periphery of the inner peripheral wall
surface 106a of the bearing housing 106. The insert plate portion 94 is configured to be
25 inserted in the second circumferential groove 99 over the entire periphery of the inner
peripheral wall surface 106a of the bearing housing 106.
[0086] According to the embodiment as above, the diffuser component 9 can be reliably
fixed in the bearing housing 106 because the insert plate portion 94 of the diffuser component
14-643PCT
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9 is inserted in the second circumferential groove 99 over the entire periphery of the inner
peripheral wall surface 106a of the bearing housing 106.
[0087] In several embodiments, as illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 5A, FIG.
5B, FIG. 5C, FIG. 6A, FIG. 6B, and FIG. 6C, the first circumferential groove 81 is formed
over the entire periphery of the inner peripheral wall surface 5 106a of the bearing housing 106.
The snap ring 8 has a spaced section 82 formed by separating end portions 8a and 8b of an arc
shape from each other. Specifically, the snap ring 8 is formed to have a C-shape in which a
part of the annular shape is cut out. The outer peripheral-side plate portion 92 of the diffuser
component 9 includes a first outer peripheral-side plate portion 921 and a second outer
10 peripheral-side plate portion 922. The second outer peripheral-side plate portion 922 is
formed at a position different from that of the first outer peripheral-side plate portion 921 in
the circumferential direction and has an extending length that is shorter than that of the first
outer peripheral-side plate portion 921. The insert plate portion 94 of the diffuser
component 9 includes a first insert plate portion 941 extending from the first outer peripheral15
side plate portion 921 to the outer peripheral side and a second insert plate portion 942
extending from the second outer peripheral-side plate portion 922 to the outer peripheral side.
The second insert plate portion 942 is configured to be inserted in the second circumferential
groove 99, and the first insert plate portion 941 is configured to be inserted in the first
circumferential groove 81 at the spaced section 82 of the snap ring 8 inserted in the first
20 circumferential groove 81.
[0088] In the embodiment illustrated in the drawings, in particular, as illustrated in FIG.
4C, FIG. 5C, and FIG. 6C, the length of the first insert plate portion 941 in the circumferential
direction is shorter than the distance between one end portion 8a and the other end portion 8b
of the snap ring 8. The length of the second insert plate portion 942 in the circumferential
25 direction is not particularly limited, but is substantially the same length as the length of the
circumferential direction of the first insert plate portion 941 in the embodiment illustrated in
the drawings. The second circumferential groove 99 is formed in the circumferential
direction over at least a length equal to or longer than the length of the second insert plate
14-643PCT
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portion 942 in the circumferential direction. The first insert plate portion 941 is inserted in a
part of the first circumferential groove 81 in which the snap ring 8 is not inserted (a gap 82 of
the snap ring 8). The second insert plate portion 942 is inserted in the second
circumferential groove 99.
[0089] According to the embodiment as above, 5 the part of the bearing housing 106 to be
processed can be kept at a minimum by effectively utilizing the first circumferential groove
81 formed for inserting the snap ring 8 therein. The diffuser component 9 can be reliably
fixed in the bearing housing 106 by inserting the second insert plate portion 942 in the second
circumferential groove 99 in addition to inserting the first insert plate portion 941 in the first
10 circumferential groove 81.
[0090] In several embodiments, as illustrated in FIG. 4A, FIG. 4B, FIG. 4C, FIG. 5A, FIG.
5B, FIG. 5C, FIG. 6A, FIG. 6B, and FIG. 6C, the first insert plate portion 941 and the second
insert plate portion 942 are formed at positions opposed to each other in the circumferential
direction.
15 [0091] According to the embodiment as above, the first insert plate portion 941 and the
second insert plate portion 942 are formed at positions opposed to each other in the
circumferential direction. As a result, the diffuser component 9 can be more reliably fixed to
the inside of the bearing housing 106 because the diffuser component 9 can be supported by
two places opposed to each other in the circumferential direction.
20 [0092] In several embodiments, as illustrated in FIG. 5A, FIG. 5B, and FIG. 5C, the
diffuser component 9 includes a plate-shaped cylindrical plate portion 95 extending from the
inner peripheral end portion of the diffuser portion 91 toward the insert component 6 along
the axial direction of the rotation shaft 2. The insert component 6 has a projecting portion 67
protruding from the outer peripheral end surface 61a of the inner peripheral portion 6A to the
25 outer peripheral side, and at least one projecting portion 67 is formed in the circumferential
direction or the projecting portion 67 is formed in plurality at intervals in the circumferential
direction. A recessed portion 951 or a slit 952 in which the projecting portion 67 is inserted
when the cylindrical plate portion 95 is fitted with the outer peripheral end surface 61a of the
14-643PCT
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inner peripheral portion 6A of the insert component 6 is formed in an inner peripheral surface
95a of the cylindrical plate portion 95 along the axial direction of the rotation shaft 2.
[0093] In the embodiment illustrated in the drawings, the radially inner portion of the
diffuser component 9, specifically, the radially inner portion of the cylindrical plate portion 95
in a state before the diffuser component 9 is fitted with the outer 5 peripheral end surface 61a of
the inner peripheral portion 6A of the insert component 6 is formed to be slightly smaller than
the radially outer portion of the outer peripheral end surface 61a of the inner peripheral
portion 6A of the insert component 6. The radially outer portion of the outer peripheral end
surface 61a of the inner peripheral portion 6A of the insert component 6 is formed to be larger
10 than the radially outer portion of the compressor impeller 105. The diffuser component 9 is
inserted in the bearing housing 106 from the opening in the end portion of the bearing housing
106 on one side thereof, and the cylindrical plate portion 95 of the diffuser component 9 is
fitted with the outer peripheral end surface 61a of the inner peripheral portion 6A of the insert
component 6, to thereby fix the diffuser component 9 to the inside of the bearing housing 106.
15 [0094] According to the embodiment as above, the cylindrical plate portion 95 of the
diffuser component 9 is fitted with the outer peripheral end surface 61a of the inner peripheral
portion 6A of the insert component 6 in addition to inserting the first insert plate portion 941
in the first circumferential groove 81 and inserting the second insert plate portion 942 in the
second circumferential groove 99. As a result, the diffuser component 9 can be more
20 reliably fixed to the inside of the bearing housing 106.
[0095] The recessed portion 951 or the slit 952 in which the projecting portion 67 is
inserted when the cylindrical plate portion 95 is fitted with the outer peripheral end surface
61a of the inner peripheral portion 6A of the insert component 6 is formed in the inner
peripheral surface 95a of the cylindrical plate portion 95 along the axial direction of the
25 rotation shaft 2. As a result, the diffuser component 9 can be easily positioned in the
circumferential direction by inserting the diffuser component 9 in the bearing housing 106
along the axial direction of the rotation shaft 2 so that the projecting portion 67 is inserted in
the recessed portion 951 or the slit 952. In (a) of FIG. 5B, the upper part of the view
14-643PCT
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illustrates a state in which the projecting portion 67 is inserted in the recessed portion 951
formed in the inner peripheral surface 95a of the cylindrical plate portion 95, and the lower
part of the view illustrates a state in which the projecting portion 67 is inserted in the slit 952
formed in the inner peripheral surface 95a of the cylindrical plate portion 95.
[0096] In several embodiments, as illustrated in FIG. 6A, FIG. 5 6B, FIG. 6C, FIG. 7A, and
FIG. 7B, the diffuser component 9 includes a plate-shaped horizontal plate portion 96
extending from the inner peripheral end portion of the diffuser portion 91 toward the insert
component 6 along the axial direction of the rotation shaft 2. A bulged portion 961 bulging
more than other portions of the horizontal plate portion 96 is formed on the distal end of the
10 horizontal plate portion 96. As illustrated in the upper part of FIG. 10, a fitting groove 621
with which the distal end of the horizontal plate portion 96 can be fitted is formed in the outer
peripheral-side wall portion 62 of the insert component 6.
[0097] In the embodiment illustrated in the drawings, the horizontal plate portion 96 is
formed to be an annular shape continuous in the circumferential direction, but the horizontal
15 plate portion 96 may be formed in only a part of the circumferential direction. The bulged
portion 961 is formed by bending the distal end of the horizontal plate portion 96 into a curve.
However, the shape and the processing method of the bulged portion 961 are not limited
thereto. The bulged portion 961 only needs to have a shape bulging more than other
portions of the horizontal plate portion 96 so as to be able to be fitted with the fitting groove
20 621.
[0098] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the distal end of the horizontal
plate portion 96 of the diffuser component 9 is simply fitted with the fitting groove 621 in the
insert component 6.
25 [0099] In several embodiments, as illustrated in FIG. 2A, FIG. 2B, FIG. 3A, FIG. 3B, FIG.
4A, FIG. 4B, FIG. 4C, FIG. 5A, FIG. 5B, FIG. 5C, FIG. 6A, FIG. 6B, FIG. 6C, FIG. 7A, and
FIG. 7B, the diffuser component 9 includes a plate-shaped component formed by bending a
metallic plate.
14-643PCT
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[0100] According to the embodiment as above, the diffuser component 9 can be formed
by a simple method of simply bending a metallic plate. Furthermore, the surface roughness
of a metallic plate is higher than that of a casting and the like. As a result, according to the
embodiment as above, the pressure loss in the diffuser flow path 112 can be reduced because
the diffuser portion 91 defining the diffuser 5 flow path 112 is made of a metallic plate.
[0101] In several embodiments, as illustrated in FIG. 8A and FIG. 8B, a screw hole 97
with which a screw component 10 can be threadedly engaged is formed in the diffuser portion
91 of the diffuser component 9. As illustrated in the lower part of FIG. 10, a screw hole 622
with which the screw component 10 can be threadedly engaged is formed in the outer
10 peripheral-side wall portion 62 of the insert component 6. The diffuser component 9 is
configured to be fastened with the insert component 6 by threadedly engaging the screw
component 10 with the screw hole 97 in the diffuser component 9 and the screw hole 622 in
the insert component 6 from the diffuser surface 91a of the diffuser component 9.
[0102] In the embodiment illustrated in the drawings, the diffuser portion 91 of the
15 diffuser component 9 has a thickness needed for the formation of the screw hole 97. For
example, the diffuser component 9 as above is made of cast metal or heat-resistant resin.
[0103] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the diffuser component 9 is
simply threadedly engaged with the insert component 6 by the screw component 10.
20 [0104] In several embodiments, as illustrated in FIG. 9A and FIG. 9B, a screw groove
106b having a predetermined length is formed in the inner peripheral wall surface 106a of the
bearing housing 106 from the end portion of the bearing housing 106 on one side thereof
along the axial direction of the rotation shaft 2. The diffuser component 9 is formed into an
annular shape, and a screw thread 98 that can threadedly engage with the screw groove 106b
25 is formed in the outer peripheral surface of the diffuser component 9.
[0105] According to the embodiment as above, the diffuser component 9 can be fixed in
the bearing housing 106 through a simple structure in which the outer peripheral surface of
the diffuser component 9 and the inner peripheral wall surface 106a of the bearing housing
14-643PCT
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106 are simply threadedly engaged with each other.
[0106] While preferred embodiments of this invention have been described, this invention
is not limited to the embodiments described above. For example, the embodiments
described above may be combined and various changes can be made without departing from
5 the object of this invention.
[0107] For example, in the embodiments described above, an example in which the
turbocharger 100 is a turbocharger is described, but the turbocharger of this invention is not
limited thereto. The turbocharger of this invention may be, for example, an electric
compressor in which a rotation shaft rotates by a motor, or a mechanical supercharger in
10 which a rotation shaft rotates by power transmitted from a crankshaft or the like.
Reference Signs List
[0108]
2 Rotation shaft
15 3A First thrust collar
3A1 Collar main body portion
3A2 Radially large portion
3B Second thrust collar
3B1 Collar main body portion
20 3B2 Large-diameter portion
4 Thrust plate
4A Insertion hole
4a One surface
4b Other surface
25 5 Oil deflector
6 Insert component
6A Inner peripheral portion
6B Outer peripheral portion
14-643PCT
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6C Insert portion
61 Inner peripheral-side wall portion
61a Outer peripheral end surface
62 Outer peripheral-side wall portion
5 621 Fitting groove
622 Screw hole
63 Protruding portion
63a Outer peripheral surface
63b Step portion
10 64 Extension portion
65 Connection portion
66 Projecting portion
66a Outer peripheral end
67 Projecting portion
15 7 Seal component
8 Snap ring
8a One end portion
8b Other end portion
81 First circumferential groove
20 82 Spaced section
9 Diffuser component
91 Diffuser portion
91a Diffuser surface
92 Outer peripheral-side plate portion
25 921 First outer peripheral-side plate portion
922 Second outer peripheral-side plate portion
93 Inner peripheral-side plate portion
931 Horizontal portion
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932 Vertical portion
93a Inner peripheral end
94 Insert plate portion
941 First insert plate portion
5 942 Second insert plate portion
95 Cylindrical plate portion
951 Recessed portion
952 Slit
95a Inner peripheral surface
10 96 Horizontal plate portion
961 Bulged portion
97 Screw hole
98 Screw thread
99 Second circumferential groove
15 10 Screw component
100 Turbocharger
102 Turbine housing
103 Turbine impeller
103A Turbine hub
20 103B Turbine blade
104 Compressor housing
105 Compressor impeller
105A Compressor hub
105B Compressor blade
25 105a Outer peripheral edge
106 Bearing housing
106A Protruding wall portion
106a Inner peripheral wall surface
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106b Screw groove
110 Radial bearing
111 Exhaust gas discharging flow path
112 Diffuser flow path
5 113 Turbine scroll flow path
115 Intake air introducing flow path
116 Nut
117 Compressor scroll flow path
118 Lubricant oil introducing path
10 119 Lubricant oil outlet
14-643PCT

CLAIMS
1. A turbocharger, comprising:
a rotation shaft;
a compressor impeller provided on one end side of the rotation shaft;
a compressor housing 5 configured to accommodate the compressor impeller;
a bearing housing connected to the compressor housing at an end portion of the bearing
housing on one side thereof, the bearing housing being configured to define, between the
bearing housing and the compressor housing, a diffuser flow path which extends along a
direction orthogonal to an axis of the rotation shaft and through which intake air compressed
10 by the compressor impeller flows, the bearing housing comprising therein a protruding wall
portion protruding from an inner peripheral wall surface of the bearing housing;
a thrust plate accommodated in the bearing housing and configured to support the
rotation shaft in an axial direction;
an insert component accommodated in the bearing housing at a position closer to the
15 end portion of the bearing housing on one side thereof than a position of the thrust plate in the
axial direction of the rotation shaft, and configured to retain the thrust plate between the insert
component and the protruding wall portion;
a snap ring accommodated in the bearing housing and configured to be inserted in a first
circumferential groove formed in the inner peripheral wall surface of the bearing housing, to
20 thereby fix the insert component in a state in which the insert component is pressed against
the thrust plate; and
a diffuser component accommodated in the bearing housing and having a diffuser
surface that defines a part of the diffuser flow path extending along the direction orthogonal to
the axis of the rotation shaft between the inner peripheral wall surface of the end portion of
25 the bearing housing on one side thereof and an outer peripheral edge of the compressor
impeller.
2. The turbocharger according to claim 1,
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wherein the insert component comprises:
an inner peripheral portion comprising an inner peripheral-side wall portion
extending along the direction orthogonal to the axis of the rotation shaft; and
an outer peripheral portion comprising:
an outer peripheral-side wall 5 portion extending along the direction
orthogonal to the axis of the rotation shaft at a position farther from the end portion of the
bearing housing on one side thereof than a position of the inner peripheral-side wall portion;
and
a protruding portion protruding from the outer peripheral-side wall portion
10 toward the thrust plate,
wherein the snap ring is configured to be positioned on an outer peripheral side of the
inner peripheral portion of the insert component and come into abutment with the outer
peripheral-side wall portion of the insert component in a state in which the snap ring is
inserted in the first circumferential groove, and
15 wherein the diffuser component is configured to be positioned on an outer peripheral
side of the inner peripheral portion of the insert component.
3. The turbocharger according to claim 2,
wherein the diffuser component comprises:
20 a plate-shaped diffuser portion having the diffuser surface; and
a plate-shaped outer peripheral-side plate portion extending along the axial
direction of the rotation shaft from an outer peripheral end portion of the diffuser portion, and
wherein the outer peripheral-side plate portion is configured to come into abutment with
an inner peripheral wall surface of the bearing housing along the axial direction of the rotation
25 shaft.
4. The turbocharger according to claim 3,
wherein the insert component comprises a projecting portion protruding from an outer
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peripheral end portion of the inner peripheral portion to an outer peripheral side,
wherein the diffuser component comprises a plate-shaped inner peripheral-side plate
portion extending from an inner peripheral end portion of the diffuser portion toward the inner
peripheral portion of the insert component, and
wherein in a state 5 in which the insert component and the diffuser component are
accommodated in the bearing housing, an inner peripheral end of the inner peripheral-side
plate portion is configured to be positioned farther from the end portion of the bearing
housing on one side thereof than the projecting portion in the axial direction of the rotation
shaft, and positioned closer to the rotation shaft than an outer peripheral end of the projecting
10 portion is in the direction orthogonal to the axis of the rotation shaft.
5. The turbocharger according to claim 3 or 4,
wherein a radially outer portion of the diffuser component is formed to be larger than a
radially inner portion of the end portion on one side of the bearing housing, and
15 wherein the diffuser component is press fitted in the bearing housing to be fixed in the
bearing housing.
6. The turbocharger according to any one of claims 3 to 5,
wherein a radially inner portion of the diffuser component is formed to be smaller than a
20 radially outer portion of an outer peripheral end surface of the inner peripheral portion of the
insert component, and
wherein the diffuser component is fitted with the outer peripheral end surface of the
inner peripheral portion of the insert component to be fixed in the bearing housing.
25 7. The turbocharger according to claim 3 or 4,
wherein the inner peripheral wall surface of the bearing housing has a second
circumferential groove formed therein at a position closer to the end portion on one side of the
bearing housing than a position of the first circumferential groove in the axial direction of the
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rotation shaft,
wherein the diffuser component comprises a plate-shaped insert plate portion extending
from the outer peripheral-side plate portion to an outer peripheral side, and
wherein the insert plate portion is configured to be inserted in the second
5 circumferential groove.
8. The turbocharger according to claim 7,
wherein the second circumferential groove is formed over an entire periphery of the
inner peripheral wall surface of the bearing housing, and
10 wherein the insert plate portion is configured to be inserted in the second
circumferential groove over the entire periphery of the inner peripheral wall surface of the
bearing housing.
9. The turbocharger according to claim 7,
15 wherein the first circumferential groove is formed over an entire periphery of the inner
peripheral wall surface of the bearing housing,
wherein the snap ring has a spaced section formed by spacing both end portions of an
arc shape,
wherein the outer peripheral-side plate portion of the diffuser component comprises:
20 a first outer peripheral-side plate portion; and
a second outer peripheral-side plate portion formed at a position different from the
first outer peripheral-side plate portion in a circumferential direction and having an extending
length shorter than an extending length of the first outer peripheral-side plate portion,
wherein the insert plate portion of the diffuser component comprises:
25 a first insert plate portion extending from the first outer peripheral-side plate
portion to the outer peripheral side; and
a second insert plate portion extending from the second outer peripheral-side plate
portion to the outer peripheral side,
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wherein the second insert plate portion is configured to be inserted in the second
circumferential groove, and
wherein the first insert plate portion is configured to be inserted in the first
circumferential groove at the spaced section of the snap ring inserted in the first
5 circumferential groove.
10. The turbocharger according to claim 9, wherein when the diffuser component is viewed
from the axial direction of the rotation shaft, the second insert plate portion is formed at a
position opposed to the first insert plate portion in the circumferential direction.
10
11. The turbocharger according to claim 9 or 10,
wherein the diffuser component comprises a plate-shaped cylindrical plate portion
extending from an inner peripheral end portion of the diffuser portion toward the insert
component along the axial direction of the rotation shaft,
15 wherein the insert component comprises a projecting portion protruding from an outer
peripheral end surface of the inner peripheral portion to an outer peripheral side, and at least
one projecting portion is formed in the circumferential direction or a plurality of the
projecting portions are formed at intervals in the circumferential direction, and
wherein a recessed portion or a slit in which the projecting portion is inserted when the
20 cylindrical plate portion is fitted with the outer peripheral end portion of the inner peripheral
portion of the insert component is formed in an inner peripheral surface of the cylindrical
plate portion along the axial direction of the rotation shaft.
12. The turbocharger according to claim 2 or 3,
25 wherein the diffuser component comprises a plate-shaped horizontal plate portion
extending from an inner peripheral end portion of the diffuser portion toward the insert
component along the axial direction of the rotation shaft, the horizontal plate portion having a
distal end on which a bulged portion bulging more than other portions of the horizontal plate
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portion is formed, and
wherein the outer peripheral-side wall portion of the insert component has a fitting
groove formed therein with which the distal end of the horizontal plate portion is fittable.
13. The turbocharger according to any one 5 of claims 3 to 12, wherein the diffuser
component is formed of a plate-shaped component formed by bending a sheet metal.
14. The turbocharger according to claim 2,
wherein a diffuser portion of the diffuser component has a screw hole formed therein
10 with which a screw component is threadedly engageable,
wherein the outer peripheral side wall portion of the insert component has a screw hole
formed therein with which the screw component is threadedly engageable, and
wherein the diffuser component is fastened with the insert component by threadedly
engaging the screw component with the screw hole in the diffuser component and the screw
15 hole in the insert component from the diffuser surface of the diffuser component.
15. The turbocharger according to claim 2,
wherein the inner peripheral wall surface of the bearing housing has a screw groove
having a predetermined length formed therein from the end portion of the bearing housing on
20 one side thereof along the axial direction of the rotation shaft, and
wherein the diffuser component is formed to have an annular shape, and a screw thread
that is threadedly engageable with the screw groove is formed on an outer peripheral surface
of the diffuser component.