U.S. patent application number 16/340423 was filed with the patent office on 2019-07-25 for electric compressor.
This patent application is currently assigned to IHI Corporation. The applicant listed for this patent is IHI Corporation. Invention is credited to Kuniaki IIZUKA, Tatsumi INOMATA, Takashi MORI, Takuya OZASA, Yuji SASAKI, Takashi YOSHIDA, Ryosuke YUMOTO.
Application Number | 20190226486 16/340423 |
Document ID | / |
Family ID | 62145597 |
Filed Date | 2019-07-25 |
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United States Patent
Application |
20190226486 |
Kind Code |
A1 |
IIZUKA; Kuniaki ; et
al. |
July 25, 2019 |
ELECTRIC COMPRESSOR
Abstract
An electric compressor includes: a rotary shaft to which a
compressor impeller is attached; a stator portion which is disposed
around the rotary shaft; and a motor housing which accommodates the
stator portion. The motor housing includes an inner housing which
includes a first cylindrical portion surrounding and holding the
stator portion and an outer housing which includes a second
cylindrical portion surrounding and holding the first cylindrical
portion of the inner housing. Between an outer surface of the inner
housing and an inner surface of the outer housing, a cooling jacket
portion is formed in a part of a circumferential direction about
the rotary shaft. The inner housing includes a first end wall
portion which is formed to be continuous to the first cylindrical
portion and extends inward in relation to an outer peripheral
portion of the stator portion in a radial direction of the rotary
shaft.
Inventors: |
IIZUKA; Kuniaki; (Koto-ku,
JP) ; YOSHIDA; Takashi; (Koto-ku, JP) ;
SASAKI; Yuji; (Koto-ku, JP) ; INOMATA; Tatsumi;
(Koto-ku, JP) ; OZASA; Takuya; (Koto-ku, JP)
; YUMOTO; Ryosuke; (Koto-ku, JP) ; MORI;
Takashi; (Koto-ku, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
IHI Corporation |
Koto-ku |
|
JP |
|
|
Assignee: |
IHI Corporation
Koto-ku
JP
|
Family ID: |
62145597 |
Appl. No.: |
16/340423 |
Filed: |
November 17, 2017 |
PCT Filed: |
November 17, 2017 |
PCT NO: |
PCT/JP2017/041525 |
371 Date: |
April 9, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F02B 33/40 20130101;
F02B 39/00 20130101; F04D 29/584 20130101; F02B 39/10 20130101;
F02B 39/005 20130101; F04D 25/06 20130101; H02K 9/19 20130101; F04D
29/059 20130101; F04D 29/5806 20130101; F04D 29/056 20130101 |
International
Class: |
F04D 25/06 20060101
F04D025/06; F04D 29/059 20060101 F04D029/059; F04D 29/58 20060101
F04D029/58 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 21, 2016 |
JP |
2016-226091 |
Claims
1. An electric compressor comprising: a rotary shaft to which a
compressor impeller is attached; a stator portion which is disposed
around the rotary shaft; and a motor housing which accommodates the
stator portion, wherein the motor housing includes an inner housing
which includes a first cylindrical portion surrounding and holding
the stator portion and an outer housing which includes a second
cylindrical portion surrounding and holding the first cylindrical
portion of the inner housing, wherein, between an outer surface of
the inner housing and an inner surface of the outer housing, a
cooling jacket portion is formed in a part of a circumferential
direction about the rotary shaft, and wherein the inner housing
includes a first end wall portion which is formed to be continuous
to the first cylindrical portion and extends inward in relation to
an outer peripheral portion of the stator portion in a radial
direction of the rotary shaft.
2. The electric compressor according to claim 1, wherein the
cooling jacket portion includes a first end portion and a second
end portion which are an inlet and an outlet of a cooling
fluid.
3. The electric compressor according to claim 1, wherein a contact
plane in which the outer surface of the inner housing contacts the
inner surface of the outer housing is formed between the outer
surface of the inner housing and the inner surface of the outer
housing, wherein at least one of the inner housing and the outer
housing includes a recess portion which is recessed with respect to
the contact plane and forms the cooling jacket portion, and wherein
the recess portion of the inner housing or the outer housing is
formed only in the part of the circumferential direction so that
the cooling jacket portion is formed in the part of the
circumferential direction.
4. The electric compressor according to claim 1, further
comprising: a bearing which is provided inside the motor housing
and supports the rotary shaft, wherein the first end wall portion
of the inner housing includes an annular portion through which the
rotary shaft penetrates and which surrounds the bearing and the
annular portion holds the bearing.
5. The electric compressor according to claim 2, further
comprising: a bearing which is provided inside the motor housing
and supports the rotary shaft, wherein the first end wall portion
of the inner housing includes an annular portion through which the
rotary shaft penetrates and which surrounds the bearing and the
annular portion holds the bearing.
6. The electric compressor according to claim 3, further
comprising: a bearing which is provided inside the motor housing
and supports the rotary shaft, wherein the first end wall portion
of the inner housing includes an annular portion through which the
rotary shaft penetrates and which surrounds the bearing and the
annular portion holds the bearing.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to an electric
compressor.
BACKGROUND ART
[0002] Conventionally, an electric supercharger disclosed in Patent
Documents 1 and 2 is known. The electric supercharger includes a
motor stator and a motor rotor. The electric supercharger described
in Patent Document 1 includes a stator assembly in which a motor
stator is integrated with an outer sleeve supporting the motor
stator. A water cooling jacket is provided between an outer sleeve
and a bearing housing. Also in the electric supercharger described
in Patent Document 2, a space is provided around the motor
stator.
CITATION LIST
Patent Literature
[0003] Patent Document 1: International Publication No.
2008/020512
[0004] Patent Document 2: Japanese Unexamined Patent Publication
No. 2007-321698
SUMMARY OF INVENTION
Technical Problem
[0005] In the above-described conventional electric supercharger
(electric compressor), the cooling of the stator portion is
considered, but there are other elements that generate heat in the
vicinity of a rotation body (a rotary shaft or the like) rotating
together with a compressor impeller. Therefore, it is required to
further improve cooling efficiency of the entire electric
compressor. The present disclosure will describe an electric
compressor capable of improving cooling efficiency.
Solution to Problem
[0006] An electric compressor according to an aspect of the present
disclosure includes: a rotary shaft to which a compressor impeller
is attached; a stator portion which is disposed around the rotary
shaft; and a motor housing which accommodates the stator portion,
in which the motor housing includes an inner housing which includes
a first cylindrical portion surrounding and holding the stator
portion and an outer housing which includes a second cylindrical
portion surrounding and holding the first cylindrical portion of
the inner housing, in which, between an outer surface of the inner
housing and an inner surface of the outer housing, a cooling jacket
portion is formed in a part of a circumferential direction about
the rotary shaft, or over the entire circumference about the rotary
shaft, and in which the inner housing includes a first end wall
portion which is foiined to be continuous to the first cylindrical
portion and extends inward in relation to an outer peripheral
portion of the stator portion in a radial direction of the rotary
shaft.
Effects of Invention
[0007] According to an aspect of the present disclosure, it is
possible to improve cooling efficiency.
BRIEF DESCRIPTION OF DRAWINGS
[0008] FIG. 1 is a cross-sectional view illustrating a centrifugal
compressor according to an embodiment of the present
disclosure.
[0009] FIG. 2 is a cross-sectional view illustrating a motor
housing of FIG. 1.
[0010] FIG. 3 is a cross-sectional view taken along a line III-III
of FIG. 2.
[0011] FIG. 4 is a perspective view illustrating an inner housing
of FIG. 1.
[0012] FIG. 5 is a perspective view illustrating an outer housing
of FIG. 1.
[0013] FIG. 6 is a cross-sectional view illustrating a first step
of an assembly process.
[0014] FIG. 7 is a cross-sectional view illustrating a second step
of the assembly process.
DESCRIPTION OF EMBODIMENTS
[0015] An electric compressor according to an aspect of the present
disclosure includes: a rotary shaft to which a compressor impeller
is attached; a stator portion which is disposed around the rotary
shaft; and a motor housing which accommodates the stator portion,
in which the motor housing includes an inner housing which includes
a first cylindrical portion surrounding and holding the stator
portion and an outer housing which includes a second cylindrical
portion surrounding and holding the first cylindrical portion of
the inner housing, in which, between an outer surface of the inner
housing and an inner surface of the outer housing, a cooling jacket
portion is formed in a part of a circumferential direction about
the rotary shaft, or over the entire circumference about the rotary
shaft, and in which the inner housing includes a first end wall
portion which is formed to be continuous to the first cylindrical
portion and extends inward in relation to an outer peripheral
portion of the stator portion in a radial direction of the rotary
shaft.
[0016] According to the electric compressor, when a cooling fluid
flows in the cooling jacket portion, a heating part (a motor or the
like) of the electric compressor can be cooled through the inner
housing. The stator portion can be cooled by the first cylindrical
portion. In addition, the first end wall portion extends inward in
relation to the outer peripheral portion of the stator portion in
the radial direction. Not only the motor but also other heating
parts around the rotary shaft can be cooled by the first end wall
portion. Thus, it is possible to improve cooling efficiency.
[0017] In some aspects, the cooling jacket portion is formed in the
part of the circumferential direction. The cooling jacket portion
includes a first end portion and a second end portion which are an
inlet and an outlet of a cooling fluid. In this case, the cooling
fluid flows from the first end portion to the second end portion or
from the second end portion to the first end portion. Since it is
possible to suppress the stagnation or drift of the cooling fluid,
cooling efficiency is further improved. The positions of the inlet
and the outlet of the cooling fluid can be changed by the
configuration of the peripheral device provided with the electric
compressor, but such a change can be flexibly handled by
appropriately changing the position of the cooling jacket portion
(the positions of the first and second end portions).
[0018] In some aspects, a contact plane in which the outer surface
of the inner housing contacts the inner surface of the outer
housing is formed between the outer surface of the inner housing
and the inner surface of the outer housing, at least one of the
inner housing and the outer housing includes a recess portion which
is recessed with respect to the contact plane and forms the cooling
jacket portion, and the recess portion of the inner housing or the
outer housing is formed only in the part of the circumferential
direction so that the cooling jacket portion is formed in the part
of the circumferential direction. In this case, the cooling jacket
portion can be arbitrarily formed by appropriately changing the
position (range) or size of the recess portion.
[0019] In some aspects, the electric compressor includes a bearing
which is provided inside the motor housing and supports the rotary
shaft and the first end wall portion of the inner housing includes
an annular portion through which the rotary shaft penetrates and
which surrounds the bearing and the annular portion holds the
bearing. In this case, the bearing can be cooled through the
annular portion of the first end wall portion. Not only the motor
but also the bearing can be efficiently cooled.
[0020] Hereinafter, an embodiment of the present disclosure will be
described with reference to the drawings. In the description of the
drawings, the same elements are denoted by the same reference
numerals and a redundant description is omitted. In the description
below, the terms of the "radial direction" and the "circumferential
direction" are used with reference to a rotary shaft 12 or a
rotation axis X unless otherwise specified.
[0021] Referring to FIG. 1, an electric compressor 1 of a first
embodiment will be described. As illustrated in FIG. 1, the
electric compressor 1 is applied to, for example, an internal
combustion engine of a vehicle or a ship. The electric compressor 1
includes a compressor 7. The electric compressor 1 rotates a
compressor impeller 8 by the interaction of a rotor portion 13 and
a stator portion 14 to compress a gas such as air and generate
compressed air. The rotor portion 13 and the stator portion 14
constitute a motor 5.
[0022] The electric compressor 1 includes the rotary shaft 12 which
is rotatably supported inside a housing 2 and the compressor
impeller 8 which is attached to a front end portion of the rotary
shaft 12. The housing 2 includes a motor housing 3 which
accommodates the rotor portion 13 and the stator portion 14, an
inverter housing 4 which closes an opening of a second end side
(the left side of the drawing) of the motor housing 3 and a
compressor housing 6 which accommodates the compressor impeller 8.
The compressor housing 6 is provided at a first end side (the right
side of the drawing) of the motor housing 3. The compressor housing
6 includes a suction port 9, a scroll portion 10, and a discharge
port 11.
[0023] The rotor portion 13 is fixed to a center portion of the
rotary shaft 12 in the direction of the rotation axis X and
includes one or plural permanent magnets (not illustrated) attached
to the rotary shaft 12. The stator portion 14 is held by the inner
surface of the motor housing 3 to surround the rotor portion 13.
That is, the stator portion 14 is disposed around the rotary shaft
12. The stator portion 14 includes a cylindrical core portion 14a
which is disposed to surround the rotor portion 13 and a coil
portion 14b which is formed by winding a conductive wire (not
illustrated) around the core portion 14a. When an AC current flows
to the coil portion 14b of the stator portion 14 through the
conductive wire, the rotary shaft 12 and the compressor impeller 8
rotate together by the interaction of the rotor portion 13 and the
stator portion 14. When the compressor impeller 8 rotates, the
compressor impeller 8 sucks external air through the suction port
9, compresses the air through the scroll portion 10, and discharges
the compressed air from the discharge port 11. The compressed air
discharged from the discharge port 11 is supplied into the
above-described internal combustion engine.
[0024] The electric compressor 1 includes two bearings 20A and 20B
which rotatably support the rotary shaft 12 with respect to the
housing 2. The bearings 20A and 20B are provided inside the motor
housing 3. The bearings 20A and 20B are disposed with the motor 5
interposed therebetween and support the rotary shaft 12 at both
ends thereof The first bearing 20A is held by an annular portion 37
provided at an end portion on the side of the compressor impeller 8
in the motor housing 3. The second bearing 20B is held by the inner
surface side (the side of the compressor impeller 8) of the
partition wall portion 4a of the inverter housing 4.
[0025] Next, a configuration of the motor housing 3 will be
described in more detail with reference to FIGS. 1 and 2. The motor
housing 3 includes a cylindrical inner housing 3A which is disposed
at the inside, that is, the side of the rotary shaft 12 and a
cylindrical outer housing 3B which is disposed at the outside, that
is, the outer peripheral side of the inner housing 3A. That is, the
motor housing 3 has a structure divided into two parts. The inner
housing 3A and the outer housing 3B are separate members and are
arranged concentrically with respect to the rotation axis X. The
inner housing 3A is attached to the outer housing 3B by, for
example, tightening fitting (shrink fitting or the like).
[0026] The inner housing 3A surrounds and holds the stator portion
14. The stator portion 14 is attached to the inner housing 3A by,
for example, shrink fitting or press inserting. Accordingly, the
inner housing 3A and the stator portion 14 are unitized. The outer
housing 3B surrounds and holds the inner housing 3A. The inner
housing 3A and the stator portion 14 which are unitized are
attached to the outer housing 3B by, for example, tightening
fitting (shrink fitting or the like).
[0027] The inner housing 3A includes a first cylindrical portion 31
which has a cylindrical shape and extends in the direction of the
rotation axis X and a first end wall portion 33 which is formed to
be continuous to a first end side (the side of the compressor
impeller 8) of the first cylindrical portion 31. The first
cylindrical portion 31 surrounds and holds the stator portion 14. A
second end (an opposite side to the first end wall portion 33) of
the first cylindrical portion 31 is opened. The first end wall
portion 33 extends inward in the radial direction from the first
end of the first cylindrical portion 31 (see FIGS. 4 and 6).
[0028] The first end wall portion 33 includes the annular portion
37 which is provided at the center side, that is, the side of the
rotation axis X. The annular portion 37 protrudes in the direction
of the rotation axis X (the side of the compressor impeller 8) in
relation to the first end of the first cylindrical portion 31. An
annular outer surface 33b is formed around the annular portion 37.
The outer surface 33b is a shoulder portion which is provided
between the first cylindrical portion 31 and the annular portion
37. The outer surface 33b is a flat surface which extends in a
direction perpendicular to the rotation axis X. The annular portion
37 is disposed around the rotation axis X. A through-hole 37d is
provided at the center of the annular portion 37. A boss portion 8b
of the compressor impeller 8 and the rotary shaft 12 are inserted
through the through-hole 37d and the rotary shaft 12 penetrates the
annular portion 37.
[0029] As illustrated in FIG. 1, the annular portion 37 extends
inward in relation to the outer peripheral portion of the stator
portion 14 in the radial direction. The annular portion 37
surrounds the first bearing 20A. The annular portion 37 includes a
cylindrical bearing accommodation portion which is continuous to
the through-hole 37d and holds the first bearing 20A in the inner
peripheral surface 37c.
[0030] The outer housing 3B includes a second cylindrical portion
32 which has a cylindrical shape and extends in the direction of
the rotation axis X and a second end wall portion 34 which is
provided to be continuous to the first end of the second
cylindrical portion 32. The second cylindrical portion 32 surrounds
and holds the first cylindrical portion 31 of the inner housing 3A.
The second end of the second cylindrical portion 32 is opened. The
second end wall portion 34 extends inward in the radial direction
from the first end of the second cylindrical portion 32. As
illustrated in FIGS. 2, 5, and 7, the second end wall portion 34 is
formed in an annular shape and is disposed around the rotation axis
X. An inner surface 34b of the second end wall portion 34 in the
radial direction is a flat surface which extends in a direction
perpendicular to the rotation axis X. An opening is formed at the
center of the second end wall portion 34 and the annular portion 37
of the inner housing 3A is disposed inside the opening. As
illustrated in FIG. 1, the annular portion 37 and the first bearing
20A are disposed inside the opening of the second end wall portion
34.
[0031] As illustrated in FIGS. 2 and 7, the inner housing 3A is
inserted from the second end side of the outer housing 3B and is
fitted into the outer housing 3B. The inner housing 3A is fitted
into the outer housing 3B while holding the stator portion 14. An
outer peripheral surface 31a of the first cylindrical portion 31
comes into contact with an inner peripheral surface 32a of the
second cylindrical portion 32. The outer peripheral surface 31a may
be in close contact with the inner peripheral surface 32a. A first
contact plane S1 having a cylindrical shape is formed by the outer
peripheral surface 31a and the inner peripheral surface 32a. A
first seal member 36 having an annular shape is formed between the
outer peripheral surface 31a and the inner peripheral surface 32a.
The first seal member 36 is provided in one seal groove 31c (see
FIG. 6) formed in the outer peripheral surface 31a of the first
cylindrical portion 31. The first seal member 36 is, for example,
an O-ring.
[0032] The outer surface 33b of the first end wall portion 33 comes
into contact with the inner surface 34b of the second end wall
portion 34. The outer surface 33b may abut against the inner
surface 34b. A second contact plane 52 having a flat annular shape
is formed by the outer surface 33b and the inner surface 34b. An
outer peripheral surface 37a of the annular portion 37 comes into
contact with an inner peripheral surface 34a of the second end wall
portion 34. The first end wall portion 33 and the second end wall
portion 34 face a back surface 8a of the compressor impeller 8 with
a slight gap therebetween (see FIG. 1). The outer peripheral
surface 37a may be in close contact with the inner peripheral
surface 34a. A second seal member 38 having an annular shape is
provided between the outer peripheral surface 37a and the inner
peripheral surface 34a. The second seal member 38 is provided in
one seal groove 37b (see FIG. 6) formed in the outer peripheral
surface 37a of the annular portion 37. The second seal member 38
is, for example, an O-ring.
[0033] The inner housing 3A and the outer housing 3B may be held at
any one of the outer peripheral surface 31a and the inner
peripheral surface 32a or the outer peripheral surface 37a and the
inner peripheral surface 34a. The outer peripheral surface 31a and
the inner peripheral surface 32a may be connected to each other by
tightening fitting (shrink fitting or the like) and the outer
peripheral surface 37a and the inner peripheral surface 34a may be
fitted to each other with a gap therebetween. In contrast, the
outer peripheral surface 31a and the inner peripheral surface 32a
may be fitted to each other with a gap therebetween and the outer
peripheral surface 37a and the inner peripheral surface 34a may be
connected to each other by tightening fitting (shrink fitting or
the like). A gap may be formed between the outer peripheral surface
37a and the inner peripheral surface 34a fitted to each other with
a gap therebetween or the outer peripheral surface 31a and the
inner peripheral surface 32a fitted to each other with a gap
therebetween. Due to an assembling operation by tightening fitting,
for example, the inner housing 3A is easily aligned to the outer
housing 3B.
[0034] The inner housing 3A and the outer housing 3B are formed of
the same material. The inner housing 3A and the outer housing 3B
are formed of, for example, aluminum. As described above, the inner
housing 3A is attached into the outer housing 3B by, for example,
shrink fitting. In the assembly, the assembling operation can be
performed by heating only the outer housing 3B. If the inner
housing 3A and the outer housing 3B are formed of the same
material, even when both housings are thermally expanded in use,
the tightening margin substantially does not change.
[0035] The inner housing 3A and the outer housing 3B can be
respectively manufactured by, for example, die casting or the like.
Since the inner housing 3A and the outer housing 3B are molded by a
method not using a core, both housings can be simply manufactured.
Furthermore, when the inner housing 3A and the outer housing 3B are
manufactured by die casting or the like, a draft angle is formed in
the inner peripheral surface 32a of the outer housing 3B. Depending
on the shape of the die, a draft angle is formed in the outer
peripheral surface 31a of the inner housing 3A. In order to easily
fit the inner housing 3A and the outer housing 3B to each other,
machining may be performed on the inner peripheral surface 32a of
the outer housing 3B and/or the outer peripheral surface 31a of the
inner housing 3A to remove a draft angle.
[0036] The electric compressor 1 of the embodiment has a structure
for cooling components provided inside the motor housing 3 through
the motor housing 3. As illustrated in FIGS. 1 and 2, a water
cooling jacket portion 40 for circulating a cooling fluid such as
cooling water is formed between the inner surface of the outer
housing 3B (the inner peripheral surface 32a and the inner surface
34b) and the outer surface of the inner housing 3A (the outer
peripheral surface 31a and the outer surface 33b).
[0037] As illustrated in FIG. 3, the water cooling jacket portion
40 is formed only in a part in the circumferential direction. As
illustrated in FIGS. 3 to 5, the water cooling jacket portion 40 is
obtained by respectively fowling the recess portion 43 and the
recess portion 44 in the inner housing 3A and the outer housing 3B
and combining these members. In other words, the water cooling
jacket portion 40 is a space which is surrounded between the recess
portion 43 and the recess portion 44.
[0038] As illustrated in FIGS. 3 and 5, the inner surface 34b of
the outer housing 3B is provided with the recess portion 44 which
is recessed with respect to the second contact plane S2. The recess
portion 44 extends in the circumferential direction and is formed
only in the part in the circumferential direction. In other words,
the recess portion 44 has a rotationally asymmetric shape with
respect to the rotation axis X. The recess portion 44 may be
provided in a rage equal to or larger than 180.degree. and smaller
than 360.degree.. The recess portion 44 includes a first end
portion 44a and a second end portion 44b. A portion not provided
with the recess portion 44, that is, a portion between the first
end portion 44a and the second end portion 44b (a range larger than
0.degree. and smaller than 180.degree.) is provided with the flat
inner surface 34b forming the second contact plane S2.
[0039] As illustrated in FIG. 4, a continuous portion between the
first cylindrical portion 31 and the first end wall portion 33 in
the inner housing 3A is provided with the recess portion 43 which
is recessed with respect to the first contact plane S1 and the
second contact plane S2. The recess portion 43 extends in the
circumferential direction and is formed only in the part of the
circumferential direction. In other words, the recess portion 43
has a rotationally asymmetric shape with respect to the rotation
axis X. The recess portion 43 may be formed in a range equal to or
larger than 180.degree. and smaller than 360.degree.. The recess
portion 43 includes a first end portion 43a and a second end
portion 43b. A portion not provided with the recess portion 43,
that is, a portion between the first end portion 43a and the second
end portion 43b (a range larger than 0.degree. and smaller than
180.degree.) is provided with the outer peripheral surface 31a and
the outer surface 33b which form the first contact plane S1 and the
second contact plane S2.
[0040] The recess portion 43 may be formed in a range corresponding
to the recess portion 44. In a state in which the inner housing 3A
is attached to the outer housing 3B, the recess portion 43 is
combined with the recess portion 44 (to communicate with each
other). The position of the first end portion 44a may substantially
match the position of the first end portion 43a. The position of
the second end portion 44b may substantially match the position of
the second end portion 43b. The water cooling jacket portion 40 has
a rotationally asymmetric shape with respect to the rotation axis
X. The water cooling jacket portion 40 includes a first end portion
41 which is formed by the first end portion 43a and the first end
portion 44a and a second end portion 42 which is formed by the
second end portion 43b and the second end portion 44b. An
installation range of the water cooling jacket portion 40 or a
shape of the water cooling jacket portion 40 can be appropriately
changed by changing the ranges of forming the recess portion 43 and
the recess portion 44 or the shapes of the recess portion 43 and
the recess portion 44. The recess portion 43 and the recess portion
44 can be easily formed according to die casting.
[0041] The water cooling jacket portion 40 faces the outer
peripheral surface 31a and the outer surface 33b of the inner
housing 3A. Thus, a cooling fluid cools the first cylindrical
portion 31 and the first end wall portion 33 (including the annular
portion 37). It is possible to cool components installed inside the
motor housing 3 and capable of generating heat by the first
cylindrical portion 31 and the first end wall portion 33 which are
cooled.
[0042] As illustrated in FIGS. 3 and 5, the outer housing 3B may be
provided with an inflow pipe 51 and an outflow pipe 52 which are
respectively connected to the first end portion 43 a and the second
end portion 43b of the inner housing 3A. The inflow pipe 51 and the
outflow pipe 52 are connected to an external pipe and a pump so
that a cooling fluid is circulated therein.
[0043] Referring to FIGS. 6 and 7, an assembly method of the motor
housing 3 will be described. As illustrated in FIG. 6, the stator
portion 14 is attached to the inner housing 3A by shrink fitting or
press inserting. At this time, the stator portion 14 is inserted in
the direction of the rotation axis X from the second end side of
the inner housing 3A (the left side of the drawing). Accordingly,
the inner housing 3A and the stator portion 14 are unitized.
[0044] As illustrated in FIG. 7, the first seal member 36 and the
second seal member 38 are respectively attached to the seal groove
31c and the seal groove 37b of the inner housing 3A. The inner
housing 3A and the stator portion 14 which are unitized are
attached to the outer housing 3B by shrink fitting. At this time,
the inner housing 3A is inserted in the direction of the rotation
axis X from the second end side of the outer housing 3B (the left
side of the drawing). By the above-described process, it is
possible to obtain a unit from the motor housing 3 and the stator
portion 14.
[0045] According to the electric compressor 1 of the embodiment,
when a cooling fluid flows in the water cooling jacket portion 40,
a heating part (the motor 5 or the like) of the electric compressor
1 can be cooled through the inner housing 3A. The stator portion 14
can be cooled by the first cylindrical portion 31. In addition, the
first end wall portion 33 extends inward in relation to the outer
peripheral portion of the stator portion 14 in the radial
direction. By the first end wall portion 33, not only the motor but
also other peripheral heating parts of the rotary shaft 12 can be
cooled. Thus, it is possible to improve cooling efficiency.
[0046] Conventionally, a motor housing with a cooling jacket
portion was manufactured by a method such as casting using a core.
Since it was difficult to manufacture the motor housing by die
casting, a manufacturing cost was high. Further, since it was
necessary to manufacture the whole motor housing against
differences in compatibility and compressor specification,
improvement was desired from the viewpoint of component
commonality. According to the electric compressor 1 of the
embodiment, the motor housing 3 includes the inner housing 3A and
the outer housing 3B. In other words, the motor housing 3 is
divided into the inner housing 3A and the outer housing 3B. By
assembling these housings, the water cooling jacket portion 40 is
formed. Further, the first seal member 36 and the second seal
member 38 are provided at the front and rear sides of the water
cooling jacket portion 40 and a water cooling mechanism is
provided. Since a portion in which the inner housing 3A and the
outer housing 3B abut against each other is provided with the
recess portions 43 and 44 having a rotationally asymmetric shape, a
water channel shape corresponding to the inlet/outlet position of
the cooling fluid is realized. Further, the outer shape of the
outer housing 3B may be changed against differences of the shape of
the compressor impeller 8, the shape of the inverter housing 4 or
the compressor housing 6, or the mounting boss. There is no need to
change the inner housing 3A and the inner surface side of the outer
housing 3B and a common configuration may be employed.
[0047] Further, since the motor housing 3 is divided into the inner
housing 3A and the outer housing 3B, the water cooling jacket
portion 40 does not become a closed space when manufacturing each
housing and hence a core is not necessary. For this reason, the
motor housing can be manufactured by die casting or the like. Since
the inner housing 3A and the outer housing 3B are molded by a
manufacturing method such as die casting not using a core, the
motor housing is easily manufactured. In the assembly of the outer
housing 3B and the inner housing 3A, these housings can be
assembled just by heating the outer housing 3B. Although the inner
housing 3A and the outer housing 3B can be thermally expanded in a
use state, a tightening margin substantially does not change when
both housings are formed of the same material. For this reason, the
outer housing 3B can reliably hold the inner housing 3A in a use
state.
[0048] Further, since the first seal member 36 and the second seal
member 38 are provided at the front and rear sides of the water
cooling jacket portion 40, a structure that prevents the leakage of
the cooling fluid to the outside is obtained. By changing the shape
of the abutting portion, a flow passage range in the
circumferential direction can be changed. Thus, it is possible to
secure the flexibility of the inlet/outlet position of the cooling
fluid.
[0049] In the water cooling jacket portion 40 having a rotationally
asymmetric shape, the cooling fluid flows from the first end
portion 41 to the second end portion 42. Since it is possible to
suppress the stagnation or drift of the cooling fluid as compared
with a case in which the water cooling jacket portion is provided
in the entire circumference, cooling efficiency is further
improved. The positions of the inlet and the outlet of the cooling
fluid can be changed depending on the configuration of the
peripheral device provided with the electric compressor 1, but when
the position of the water cooling jacket portion 40 (the positions
of the first end portion 41 and the second end portion 42) is
appropriately changed, such a change can be also flexibly
handled.
[0050] By appropriately changing the positions (ranges) or sizes of
the recess portions 43 and 44, it is possible to form the water
cooling jacket portion 40 into an arbitrary shape.
[0051] According to the annular portion 37 which holds the first
bearing 20A, it is possible to efficiently cool not only the motor
5 but also the first bearing 20A.
[0052] Although the embodiments of the present disclosure have been
described, the present disclosure is not limited to the
above-described embodiments. For example, the second end wall
portion of the outer housing 3B may not extend inward in relation
to the outer peripheral portion of the stator portion 14. The
second end wall portion of the outer housing 3B may be omitted. The
first end wall portion of the inner housing 3A may face the entire
surface of the back surface 8a of the compressor impeller 8.
[0053] The water cooling jacket portion 40 may be formed by at
least one of the recess portion 43 and the recess portion 44. The
present disclosure is not limited to a case in which the water
cooling jacket portion 40 is formed only by the recess portions 43
and 44. The water cooling jacket portion 40 may be formed by the
recess portions 43 and 44 provided in the entire circumference and
a partition member separated from the inner housing 3A or the outer
housing 3B may be provided in a part of the water cooling jacket
portion 40. The partition member is provided inside the water
cooling jacket portion 40 and can define a flow passage shape.
[0054] The water cooling jacket portion may be formed in the
entirety (that is, the entire circumference) of the circumferential
direction. The cooling fluid is not limited to water and may be
other liquids such as oil. The present disclosure may be applied to
an electric compressor with a turbine.
INDUSTRIAL APPLICABILITY
[0055] According to some aspects of the present disclosure, it is
possible to improve cooling efficiency.
REFERENCE SIGNS LIST
[0056] 1: electric compressor, 2: housing, 3: motor housing, 3A:
inner housing, 3B: outer housing, 4: inverter housing, 4a:
partition wall portion, 5: motor, 6: compressor housing, 8:
compressor impeller, 8a: back surface, 12: rotary shaft, 14: stator
portion, 20A: first bearing, 20B: second bearing, 31: first
cylindrical portion, 31a: outer peripheral surface (outer surface),
32: second cylindrical portion, 32a: inner peripheral surface
(inner surface), 33: first end wall portion, 33b: outer surface,
34: second end wall portion, 34a: inner peripheral surface, 34b:
inner surface, 36: first seal member, 37: annular portion, 37a:
outer peripheral surface, 38: second seal member, 40: water cooling
jacket portion (cooling jacket portion), 41: first end portion, 42:
second end portion, 43: recess portion, 44: recess portion, S1:
first contact plane, S2: second contact plane, X: rotation
axis.
* * * * *