U.S. patent application number 14/631985 was filed with the patent office on 2015-09-24 for motor-driven turbo compressor.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. The applicant listed for this patent is KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. Invention is credited to Toshiro FUJII, Nobuaki HOSHINO, Hajime KURITA, Hironao YOKOI.
Application Number | 20150267709 14/631985 |
Document ID | / |
Family ID | 52633133 |
Filed Date | 2015-09-24 |
United States Patent
Application |
20150267709 |
Kind Code |
A1 |
HOSHINO; Nobuaki ; et
al. |
September 24, 2015 |
MOTOR-DRIVEN TURBO COMPRESSOR
Abstract
In the compressor of the present invention, an intermediate
pressure port through which a first discharge chamber and a first
chamber communicate with each other is formed in a front housing.
In the front housing, an injection port through which a receiver
and a second chamber communicate with each other is formed. An
intermediate pressure refrigerant discharged to the first discharge
chamber flows into the first chamber through an intermediate
pressure port. An injection refrigerant separated by the receiver
flows into the second chamber. In the compressor, it is possible to
cool an electric motor with the intermediate pressure refrigerant
and the injection refrigerant. The intermediate pressure
refrigerant and the injection refrigerant circulate through a
second suction port as a mixed refrigerant.
Inventors: |
HOSHINO; Nobuaki;
(Kariya-shi, JP) ; FUJII; Toshiro; (Kariya-shi,
JP) ; KURITA; Hajime; (Kariya-shi, JP) ;
YOKOI; Hironao; (Kariya-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA TOYOTA JIDOSHOKKI |
Kariya-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Kariya-shi
JP
|
Family ID: |
52633133 |
Appl. No.: |
14/631985 |
Filed: |
February 26, 2015 |
Current U.S.
Class: |
417/423.7 ;
415/199.4 |
Current CPC
Class: |
H02K 9/12 20130101; F04D
17/122 20130101; F04D 29/284 20130101; F25B 1/04 20130101; H02K
7/14 20130101; F04D 29/5846 20130101; F04D 25/06 20130101; F04D
17/10 20130101; F04D 29/5806 20130101; H02K 2205/03 20130101; H02K
5/1672 20130101 |
International
Class: |
F04D 25/06 20060101
F04D025/06; F04D 29/28 20060101 F04D029/28; F04D 17/10 20060101
F04D017/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 19, 2014 |
JP |
2014-056133 |
Claims
1. A motor-driven turbo compressor used in a refrigeration cycle,
comprising: a housing; an electric motor provided in the housing; a
rotating shaft driven to rotate by the electric motor; and a first
impeller and a second impeller arranged on the rotating shaft at an
interval in an axial direction of the rotating shaft, wherein a
refrigerant is sucked from a first suction port, compressed by
rotation of the first impeller, and discharged to a first discharge
chamber provided on a radially outer circumference side of the
first impeller, and wherein the refrigerant through the first
discharge chamber is sucked from a second suction port, compressed
by rotation of the second impeller, and discharged to a second
discharge chamber provided on a radially outer circumference side
of the second impeller; wherein the first impeller, the second
impeller, and the electric motor are arranged in the axial
direction of the rotating shaft in this order, wherein a first
chamber and a second chamber are formed at both ends in the axial
direction of the electric motor in the housing and communicate with
each other via a gap in the electric motor, the first chamber is
located close to the second impeller in the axial direction of the
electric motor, and wherein an intermediate pressure port is formed
in the housing and connects the first chamber and the first
discharge chamber; and wherein an injection port connected to a
gas-liquid separator of the refrigeration cycle is formed in the
housing and communicates with the second chamber.
2. The motor-driven turbo compressor according to claim 1, wherein
the electric motor includes a rotor fixed to the rotating shaft and
a stator fixed to the housing, a communication path is formed
between the housing and the stator and connects the first chamber
and the second chamber in the axial direction, and a guide wall
that guides the refrigerant passed through the intermediate
pressure port to the communication path is formed in the
housing.
3. The motor-driven turbo compressor according to claim 2, wherein
the injection port is configured not to face the communication
path.
4. The motor-driven turbo compressor according to claim 3, wherein
the injection port extends in a radial direction of the
housing.
5. The motor-driven turbo compressor according to claim 3, wherein
the injection port is located at a position different from the
intermediate pressure port and the communication path around the
axis of the rotating shaft.
6. The motor-driven turbo compressor according to claim 1, wherein
the second suction port is configured to lead the refrigerant to
make contact with the rotating shaft.
Description
TECHNICAL FIELD
[0001] The present invention relates to a motor-driven turbo
compressor.
BACKGROUND ART
[0002] Japanese Patent No. 4947405 discloses a conventional
motor-driven turbo compressor (hereinafter referred to as
compressor). The compressor is adopted in a refrigeration circuit
of an air-conditioning apparatus. The compressor includes a
housing, a rotating shaft, an electric motor, a first impeller, and
a second impeller.
[0003] In the housing, a first impeller chamber, a second impeller
chamber, and a motor chamber are formed in this order in the axial
direction from one end side toward the other end side. Further, in
the housing, first and second diffusers and first and second
discharge chambers are formed. The first discharge chamber
communicates with the first impeller chamber via the first
diffuser. The second discharge chamber communicates with the second
impeller chamber via the second diffuser. Further, in the housing,
first and second suction ports and a gas injection portion are
formed. The first suction port extends in the axial direction on
the one end side of the housing and communicates with the first
impeller chamber. The second suction port communicates with the
first discharge chamber on one end side and communicates with the
second impeller chamber on the other end side. The second suction
port does not communicate with the motor chamber. The gas injection
portion communicates with the second suction port.
[0004] The refrigeration circuit includes, besides the compressor,
a condenser, first and second expansion valves, an economizer, and
an evaporator, which are connected by pipes to enable a refrigerant
to circulate therethrough. The economizer is arranged between the
first expansion valve and the second expansion valve. While
temporarily storing the refrigerant decompressed by the first
expansion valve, the economizer cools the stored refrigerant. The
economizer is connected to the gas injection portion of the
compressor by a pipe.
[0005] The rotating shaft is rotatably supported by the housing.
The electric motor is provided in the motor chamber and drives to
rotate the rotating shaft. The first impeller is coupled to one end
of the rotating shaft. The first impeller rotates in the first
impeller chamber to thereby increase kinetic energy of a
refrigerant in the first impeller chamber. Thereafter, the first
impeller converts the kinetic energy of the refrigerant into
pressure energy through the first diffuser, and compresses the
refrigerant, and discharges the compressed refrigerant to the first
discharge chamber. The second impeller is coupled to the other end
of the rotating shaft. The second impeller rotates in the second
impeller chamber to thereby increase kinetic energy of the
refrigerant in the second impeller chamber. Thereafter, the second
impeller converts the kinetic energy of the refrigerant into
pressure energy through the second diffuser, and compresses the
refrigerant, and discharges the compressed refrigerant to the
second discharge chamber.
[0006] The compressor compresses the refrigerant in two stages.
Specifically, the refrigerant is sucked from the first suction
port. The refrigerant is discharged to the first discharge chamber
through the first impeller chamber and the first diffuser, and
circulates through the second suction port. Further, in the
compressor, a gas-phase refrigerant in the economizer is supplied
from the gas injection portion to the second suction port. In this
way, in the compressor, the refrigerant discharged to the first
discharge chamber and the gas-phase refrigerant in the economizer
are mixed in the second suction port, and discharged to the second
discharge chamber through the second impeller chamber and the
second diffuser.
[0007] However, in the compressor as explained above, the electric
motor can drive to rotate the rotating shaft at high speed.
Therefore, deterioration in durability of the electric motor due to
heat generation is concerned. In the compressor, the refrigerant
circulating through the second suction port is unnecessarily heated
by passing from the electric motor having high temperature through
the housing. Therefore, the temperature of the refrigerant rises
when the refrigerant flows into the second impeller chamber from
the second suction port. As a result, efficiency of the
refrigeration circuit adopting the compressor is deteriorated.
[0008] The present invention has been devised in view of the
circumstances in the past and an object of the invention is to
provide a motor-driven turbo compressor that has high durability
and is capable of surely improving efficiency of a refrigeration
circuit.
SUMMARY OF THE INVENTION
[0009] The motor-driven turbo compressor of the invention is used
in a refrigeration cycle and comprises: a housing; an electric
motor provided in the housing; a rotating shaft driven to rotate by
the electric motor; and a first impeller and a second impeller
arranged on the rotating shaft at an interval in an axial direction
of the rotating shaft. A refrigerant is sucked from a first suction
port, compressed by rotation of the first impeller, and discharged
to a first discharge chamber provided on a radially outer
circumference side of the first impeller. The refrigerant through
the first discharge chamber is sucked from a second suction port,
compressed by rotation of the second impeller, and discharged to a
second discharge chamber provided on a radially outer circumference
side of the second impeller. The first impeller, the second
impeller, and the electric motor are arranged in the axial
direction of the rotating shaft in this order. A first chamber and
a second chamber are formed at both ends in the axial direction of
the electric motor in the housing and communicate with each other
via a gap in the electric motor, and the first chamber is located
close to the second impeller in the axial direction of the electric
motor. An intermediate pressure port is formed in the housing and
connects the first chamber and the first discharge chamber. An
injection port connected to a gas-liquid separator of the
refrigeration cycle is formed in the housing and communicates with
the second chamber.
[0010] Other aspects and advantages of the present invention will
be apparent from the embodiments disclosed in the following
description and the attached drawings, the illustrations
exemplified in the drawings, and the concept of the invention
disclosed in the entire description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a sectional view showing a compressor in an
embodiment.
[0012] FIG. 2 is a sectional view from a II-II direction in FIG. 1
according to the compressor of embodiment.
[0013] FIG. 3 is a sectional view from a III-III direction in FIG.
1 according to the compressor of embodiment.
[0014] FIG. 4 is a sectional view from the direction same as the
direction in FIG. 2 according to the compressor of embodiment.
[0015] FIG. 5 is a sectional view from a V-V direction in FIG. 1
according to the compressor of embodiment.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0016] An embodiment embodying the present invention is explained
below with reference to the drawings. A compressor in the
embodiment is a motor-driven turbo compressor for a vehicle. The
compressor is mounted on a vehicle and used in a refrigeration
cycle of an air conditioner for a vehicle.
[0017] As shown in FIG. 1, the compressor in the embodiment
includes a housing 1, a rotating shaft 3, an electric motor 5, a
first impeller 7, and a second impeller 9.
[0018] The housing 1 includes a front housing 11, an end plate 13,
and a rear housing 15.
[0019] The front housing 11 includes a first front housing 11a, a
second front housing 11b, a third front housing 11c, and a fourth
front housing 11d. In the front housing 11, the first front housing
11a, the second front housing 11b, the third front housing 11c, and
the fourth front housing 11d are joined in this order from the
front end side toward the rear end side. The front housing 11 is
formed into a substantially cylindrical shape as a whole.
[0020] In the front housing 11, first and second impeller chambers
17 and 19, first and second diffusers 21 and 23, first and second
discharge chambers 25 and 27, a motor chamber 29, an intermediate
pressure port 31, a first boss 33, first and second suction ports
35 and 37, first and second communication paths 39a and 39b, a
guide wall 41, an injection port 43, and a discharge port 45 are
formed.
[0021] The first impeller chamber 17 is formed on the front end
side of the front housing 11. More specifically, the front end side
of the first impeller chamber 17 is formed in the first front
housing 11a. The rear end side of the first impeller chamber 17 is
formed in the second front housing 11b. The first impeller chamber
17 is formed in a shape gradually expanding in diameter from the
front end side toward the rear end side. The first impeller 7 is
provided in the first impeller chamber 17.
[0022] The second impeller chamber 19 is formed behind the first
impeller chamber 17 in the front housing 11. More specifically, the
front end side of the second impeller chamber 17 is formed in the
second front housing 11b. The rear end side of the second impeller
chamber 17 is formed in the third front housing 11c. The second
impeller chamber 19 has a shape symmetric to the first impeller
chamber 17. The second impeller chamber 19 is formed in a shape
gradually contracting in diameter from the front end side toward
the rear end side. The second impeller 9 is provided in the second
impeller chamber 19. In the second front housing 11b, a first shaft
hole 47a extending in the axial direction of the housing 1 is
formed.
[0023] The first diffuser 21 is formed on the front end side of the
second front housing 11b and located on the outer circumference
side of the first impeller chamber 17. The first diffuser 21
communicates with the first impeller chamber 17 in a largest
diameter part of the first impeller chamber 17. The second diffuser
23 is formed on the front end side of the third front housing 11c
and located on the outer circumference side of the second impeller
chamber 19. The second diffuser 23 communicates with the second
impeller chamber 19 in a largest diameter part of the second
impeller chamber 19. The second diffuser 23 is formed smaller in
diameter than the first diffuser 21.
[0024] The front end side of the first discharge chamber 25 is
formed in the first front housing 11a. The rear end side of the
first discharge chamber 25 is formed in the second front housing
11b. The first discharge chamber 25 is provided on a radially outer
circumference side of the first impeller 7. As shown in FIG. 2, the
first discharge chamber 25 is located on the outer circumference
side of the first diffuser 21 and communicates with the first
diffuser 21. Consequently, the first impeller chamber 17 and the
first discharge chamber 25 communicate with each other through the
first diffuser 21. The first discharge chamber 25 is formed into a
spiral shape. The first discharge chamber 25 is formed such that
flow passage area gradually increases.
[0025] As shown in FIG. 1, the front side of the second discharge
chamber 27 is formed in the second front housing 11b. The rear end
side of the second discharge chamber 27 is formed in the third
front housing 11c. The second discharge chamber 27 is provided on a
radially outer circumference side of the second impeller 9. As
shown in FIG. 3, the second discharge chamber 27 is located on the
outer circumference side of the second diffuser 23 and communicates
with the second diffuser 23. Consequently, the second impeller
chamber 19 and the second discharge chamber 27 communicate with
each other through the second diffuser 23. Like the first discharge
chamber 25, the second discharge chamber 27 is formed into a spiral
shape. The second discharge chamber 27 is formed such that flow
passage area gradually increases.
[0026] Here, as explained above, the second diffuser 23 is smaller
in diameter than the first diffuser 21. Therefore, as shown in FIG.
4, the second discharge chamber 27 is located closer to the inner
circumference of the front housing 11 than the first discharge
chamber 25. Further, as shown in FIG. 3, the second discharge
chamber 27 communicates with the discharge port 45 on the outer
circumference side. The discharge port 45 extends in the radial
direction of the housing 1.
[0027] As shown in FIG. 1, the motor chamber 29 is formed in the
fourth front housing 11d. Consequently, in the front housing 11,
the first impeller chamber 17, the second impeller chamber 19, and
the motor chamber 29 are formed in this order from the front end
side toward the rear end side. The motor chamber 29 extends in the
axial direction of the housing 1 and defined by the end plate 13 on
the rear end side of the fourth front housing 11d.
[0028] The intermediate pressure port 31 is formed to extend across
the second to fourth front housings 11b to 11d in the axial
direction of the housing 1. As shown in FIG. 2, in the second front
housing 11b, the front end side of the intermediate pressure port
31 communicates with the outer circumference side of the first
discharge chamber 25. On the other hand, as shown in FIG. 1, in the
fourth front housing 11d, the rear end side of the intermediate
pressure port 31 communicates with the motor chamber 29. Further,
as shown in FIG. 4, in the front housing 11, the intermediate
pressure port 31 and the discharge port 45 are formed in positions
shifted in the radial direction.
[0029] As shown in FIG. 1, the first boss 33 is formed on the front
end side of the motor chamber 29 in the fourth front housing 11d
and extends toward the rear end side of the motor chamber 29 in the
axial direction of the housing 1. In the first boss 33, a second
shaft hole 47b extending in the axial direction of the housing 1 is
formed. In the second shaft hole 47b, a first radial foil bearing
49a is provided.
[0030] The first suction port 35 is formed on the front end side of
the first front housing 11a. That is, the first suction port 35 is
located on the front end side of the housing 1. The first suction
port 35 extends in the axial direction of the housing 1. The front
end side of the first suction port 35 opens on the front end face
of the first front housing 11a. The rear end side of the first
suction port 35 communicates with the first impeller chamber
17.
[0031] The second suction port 37 is formed to extend across the
rear end side of the third front housing 11c and the front end side
of the fourth front housing 11d. The rear end side of the second
suction port 37 communicates with the motor chamber 29 on the front
end side of the first boss 33. On the other hand, the front end
side of the second suction port 37 communicates with the second
impeller chamber 19. Further, the second suction port 37
communicates with the second shaft hole 47b. The second suction
port 37 faces the rotating shaft 3 such that the refrigerant is
brought into contact with the rotating shaft 3.
[0032] Both of the first communication path 39a and the second
communication path 39b are formed in the fourth front housing 11d
and extend from the front end side toward the rear end side of the
motor chamber 29 in the axial direction of the housing 1. More
specifically, the first communication path 39a and the second
communication path 39b are respectively located between the inner
wall of the motor chamber 29 and a stator 5a explained below. As
shown in FIG. 5, the first communication path 39a and the second
communication path 39b are arranged to face each other across the
electric motor 5 in the motor chamber 29. It is possible to form
only one of the first communication path 39a and the second
communication path 39b in the fourth front housing 11d. Further,
three or more communication paths may be formed in the fourth front
housing 11d.
[0033] As shown in FIG. 1, the guide wall 41 is formed on the front
end side of the motor chamber 29 in the fourth front housing 11d.
The guide wall 41 is formed further on the outer circumference side
than the first boss 33 in the fourth front housing 11d. The guide
wall 41 extends toward the rear end side of the motor chamber 29 in
the axial direction of the housing 1.
[0034] The injection port 43 is formed on the rear end side of the
fourth front housing 11d. As shown in FIG. 5, the injection port 43
extends in the radial direction of the housing 1 with respect to
the fourth front housing 11d. That is, in the compressor, the first
and second communication paths 39a and 39b extending in the axial
direction of the housing 1 and the injection port 43 extending in
the radial direction of the housing 1 do not face each other.
Further, the injection port 43 is located at a position different
from the intermediate pressure port 31 and the first and second
communication paths 39a and 39b around the axis of the rotating
shaft 3.
[0035] The endplate 13 is joined to the rear end of the fourth
front housing 11d, that is, the rear end of the front housing 11.
The rear end of the motor chamber 29 is defined by the end plate
13. In the end plate 13, a second boss 51 extending toward the
motor chamber 29 in the axial direction of the housing 1 is formed.
In the second boss 51, a third shaft hole 47c extending in the
axial direction of the housing 1 is formed. In the third shaft hole
47c, a second radial foil bearing 49b is provided.
[0036] The rear housing 15 is located in the rear of the housing 1
and joined to the end plate 13. That is, the rear housing 15
sandwiches the end plate 13 in conjunction with the front housing
11. In the rear housing 15, first and second thrust foil bearings
53a and 53b and a support plate 55 are provided. The first thrust
foil bearing 53a is located on the front end side of the support
plate 55 and sandwiched by the end plate 13 and the support plate
55. The second thrust foil bearing 53b is located on the rear end
side of the support plate 55 and sandwiched by the support plate 55
and the rear housing 15.
[0037] The rotating shaft 3 includes a rotating shaft main body
30a, a first small diameter portion 30b located on the front end
side of the rotating shaft main body 30a, and a second small
diameter portion 30c located on the rear end side of the rotating
shaft main body 30. The rotating shaft main body 30a is formed in a
largest diameter in the rotating shaft 3. On the other hand, both
of the first and second small diameter portions 30b and 30c are
formed smaller in diameter than the rotating shaft main body 30a.
The first small diameter portion 30b is formed in diameter smaller
than the second small diameter portion 30c.
[0038] The rotating shaft 3 is inserted through the housing 1 and
is capable of rotating in the housing 1. Specifically, the front
end side of the rotating shaft main body 30a is inserted through
the second shaft hole 47b and rotatably supported by the first
radial foil bearing 49a. On the other hand, the rear end side of
the rotating shaft main body 30a is inserted through the third
shaft hole 47c and rotatably supported by the second radial foil
bearing 49b. Further, the first small diameter portion 30b is
inserted through the first shaft hole 47a. The rear end side of the
first small diameter portion 30b is located in the second suction
port 37. The second small diameter portion 30c is inserted through
the support plate 55 in the rear housing 15. Consequently, the
second small diameter portion 30c and further, the rotating shaft 3
are supported by the first and second thrust foil bearings 53a and
53b via the support plate 55.
[0039] The electric motor 5 is provided in the motor chamber 29.
The electric motor 5 includes a stator 5a and a rotor 5b. Since the
electric motor 5 is provided in this way, the motor chamber 29 is
defined into a first chamber 29a and a second chamber 29b
respectively located at the axial direction both ends of the
electric motor 5. The first chamber 29a is located on the front end
side in the axial direction of the electric motor 5 and is located
closer to the second impeller chamber 19 than the stator 5a and the
rotor 5b. The second chamber 29b is located on the rear end side in
the axial direction of the electric motor 5 and is located on the
opposite side of the second impeller chamber 19 with respect to the
stator 5a and the rotor 5b, that is, closer to the end plate 13
than the stator 5a and the rotor 5b. The first chamber 29a
communicates with the first discharge chamber 25 in the axial
direction through the intermediate pressure port 31. Further, the
first chamber 29a communicates with the second shaft hole 47b and
the second impeller chamber 19 through the second suction port 37.
On the other hand, the second chamber 29b communicates with the
injection port 43.
[0040] The stator 5a is fixed to the inner wall of the motor
chamber 29. The stator 5a is electrically connected to a not-shown
battery. The rotor 5b is located on the inner circumference side of
the stator 5a. In the motor chamber 29, the rotor 5b is arranged
between the first boss 33 and the second boss 51. The rotor 5b is
fixed to the rotating shaft main body 30a. Consequently, the rotor
5b is capable of rotating integrally with the rotating shaft 3 on
the inner circumference side of the stator 5a. Here, a gap 5c is
provided between the stator 5a and the rotor 5b. The first chamber
29a and the second chamber 29b communicate with each other through
the gap 5c. Note that, in FIGS. 1 and 5, the shapes of the stator
5a and the rotor 5b are shown in a simplified form in order to
facilitate explanation.
[0041] The first impeller 7 is press-fitted into the front end side
of the first small diameter portion 30b and provided in the first
impeller chamber 17. Consequently, the first impeller 7 is capable
of rotating in the first impeller chamber 17 according to the
rotation of the rotating shaft 3. The first impeller 7 is formed in
diameter smaller than the inner diameter of the motor chamber 29.
The first impeller 7 is formed in a shape gradually expanding in
diameter from the front end side toward the rear end side. The rear
end side of the first impeller 7 is formed as a large diameter
portion 7a. Further, a plurality of blades 70 are provided at a
predetermined interval on the surface of the first impeller 7.
[0042] The second impeller 9 is press-fitted into the rear end side
of the first small diameter portion 30b and provided in the second
impeller chamber 19. Consequently, the second impeller 9 is capable
of rotating in the second impeller chamber 19 according to the
rotation of the rotating shaft 3. In this way, in the compressor,
the first impeller 7, the second impeller 9, and the electric motor
5 are arranged in this order in the axial direction of the rotating
shaft 3 from the front end side toward the rear end side.
[0043] The second impeller 9 is also formed in diameter smaller
than the inner diameter of the motor chamber 29. Further, the
second impeller 9 is formed to have the same size as the first
impeller 7. The second impeller 9 is provided in the first small
diameter portion 30b such that a large diameter portion 9a of the
second impeller 9 is located on the front end side of the front
housing 11. Consequently, in the compressor, in the front housing
11, the first impeller 7 and the second impeller 9 are arranged
with the large diameter portion 7a and the large diameter portion
9a faced to each other. Further, a plurality of blades 90 are
provided at a predetermined interval on the surface of the second
impeller 9. Note that the second impeller 9 may be formed in a
smaller diameter than the first impeller 7.
[0044] The refrigeration cycle 10 is configured by a condenser 101,
an expansion valve 102, a receiver 103, an evaporator 104, and
pipes 201 to 206 besides the compressor. The receiver 103
corresponds to the gas-liquid separator in the present invention.
The receiver 103 includes a gas-liquid separation chamber 103a. In
the receiver 103, an inlet 103b, an outlet 103c, and a gas outlet
103d are formed. The gas-liquid separation chamber 103a separates a
refrigerant flown into from the inlet 103b into a gas-phase
refrigerant and a liquid-phase refrigerant, and temporarily stores
the liquid-phase refrigerant. The liquid-phase refrigerant in the
gas-liquid separation chamber 103a flows out from the inside of the
gas-liquid separation chamber 103a through the outlet 103c. On the
other hand, the gas-phase refrigerant in the gas-liquid separation
chamber 103a, that is, an injection refrigerant flows out from the
inside of the gas-liquid separation chamber 103a through the gas
outlet 103d.
[0045] Here, since the refrigeration cycle 10 is mounted on a
vehicle, there is a strong demand for a reduction in the size of
the refrigeration cycle 10. Therefore, in the refrigeration cycle
10, a device such as an economizer is not adopted to perform the
gas-liquid separation of the refrigerant. Instead, the receiver 103
is adopted to perform the gas-liquid separation of the
refrigerant.
[0046] The discharge port 45 of the compressor and the condenser
101 are connected by a pipe 201. The condenser 101 is connected to
the expansion valve 102 by a pipe 202. The expansion valve 102 is
connected to the inlet 103b of the receiver 103 by a pipe 203. The
outlet 103c of the receiver 103 is connected to the evaporator 104
by a pipe 204. The evaporator 104 is connected to the first suction
port 35 of the compressor by a pipe 205. Further, the gas outlet
103d of the receiver 103 is connected to the injection port 43 of
the compressor by a pipe 206. In this way, the gas-liquid
separation chamber 103a and the second chamber 29b communicate with
each other.
[0047] In the compressor configured as explained above, the stator
5a rotates the rotor 5b by electricity of motor 5. Consequently,
the rotating shaft 3 is driven to rotate around a rotational axis O
in the housing 1. Therefore, the first impeller 7 rotates in the
first impeller chamber 17. The second impeller 9 rotates in the
second impeller chamber 19.
[0048] Further, a low-pressure refrigerant that passes through the
evaporator 104 is sucked into the first suction port 35 through the
pipe 205 and reaches the inside of the first impeller chamber 17.
The first impeller 7 rotating in the first impeller chamber 17
increases kinetic energy of the refrigerant in the first impeller
chamber 17. Thereafter, the first impeller 7 converts the kinetic
energy of the refrigerant into pressure energy through the first
diffuser 21, and compresses the refrigerant, and discharges the
compressed refrigerant to the first discharge chamber 25.
Consequently, the pressure of the refrigerant in the first
discharge chamber 25 changes to an intermediate pressure. The
refrigerant having the intermediate pressure, that is, an
intermediate pressure refrigerant circulates from the first
discharge chamber 25 to the first chamber 29a through the
intermediate pressure port 31 as indicated by a solid line arrow in
the FIG. 1. Here, in the compressor, in the front housing 11, the
intermediate pressure port 31 extends in the axial direction of the
housing 1. Therefore, in the compressor, it is possible to reduce a
body diameter even if the intermediate pressure port 31 is provided
to cause the first discharge chamber 25 and the first chamber 29a
to communicate with each other.
[0049] The intermediate pressure refrigerant flown into the first
chamber 29a is guided to the first communication path 39a and the
second communication path 39b by the guide wall 41. The
intermediate pressure refrigerant circulates through the first
communication path 39a and the second communication path 39b toward
the second chamber 29b. In this case, the intermediate pressure
refrigerant circulates from the first chamber 29a to the second
chamber 29b in the axial direction of the housing 1 while cooling
the stator 5a.
[0050] Further, in the compressor, the injection refrigerant
separated by the gas-liquid separation chamber 103a of the receiver
103 circulates through the pipe 206 and flows into the second
chamber 29b through the injection port 43 as indicated by an arrow
in the FIG. 1. In this case, since the injection port 43 extends in
the radial direction of the housing 1, the injection refrigerant
flows into the second chamber 29b in the radial direction of the
housing 1, that is, a direction orthogonal to the intermediate
pressure refrigerant circulating through the first and second
communication paths 39a and 39b. Therefore, in the compressor, it
is possible to suitably suppress a collision of the intermediate
pressure refrigerant circulating through the first and second
communication paths 39a and 39b and flowing into the second chamber
29b and the injection refrigerant flowing into the second chamber
29b from the injection port 43. Consequently, in the compressor,
the intermediate pressure refrigerant and the injection refrigerant
suitably flow into the second chamber 29b.
[0051] The intermediate pressure refrigerant and the injection
refrigerant are mixed in the second chamber 29b to be a mixed
refrigerant. The mixed refrigerant circulates through the gap 5c
between the stator 5a and the rotor 5b and circulates toward the
first chamber 29a. In this case, the stator 5a and the rotor 5b are
also cooled by the mixed refrigerant circulating through the gap
5c. The mixed refrigerant reaching the first chamber 29a flows into
the second suction port 37.
[0052] The mixed refrigerant circulating through the second suction
port 37 is sucked into the second impeller chamber 19 while coming
into contact with the first small diameter portion 30b of the
rotating shaft 3. In this case, in the compressor, it is possible
to cool the rotating shaft 3 with the mixed refrigerant circulating
through the second suction port 37.
[0053] The second impeller 9 rotating in the second impeller
chamber 19 increases kinetic energy of the mixed refrigerant in the
second impeller chamber 19. Thereafter, the second impeller 9
converts the kinetic energy of the refrigerant into pressure energy
through the second diffuser 23, and compresses the refrigerant, and
discharges the compressed refrigerant to the second discharge
chamber 27. In this way, in the compressor, the refrigerant sucked
from the first suction port 35 is compressed in two stages, and the
injection refrigerant as the mixed refrigerant also is
compressed.
[0054] As explained above, in the compressor, the electric motor 5
is cooled by the intermediate pressure refrigerant and the
injection refrigerant. The intermediate pressure refrigerant and
the injection refrigerant circulate through the second suction port
37 as the mixed refrigerant. Here, since the injection refrigerant
has low temperature, in the compressor, it is possible to suitably
suppress a temperature rise of the mixed refrigerant when the mixed
refrigerant flows into the second impeller chamber 19 from the
second suction port 37.
[0055] The injection refrigerant has high pressure compared with
the refrigerant flowing into the first impeller chamber 17 from the
first suction port 35 through the evaporator 104. Therefore, in the
compressor, it is possible to increase the pressure of the mixed
refrigerant flowing into the second suction port 37 from the first
chamber 29a.
[0056] Therefore, the compressor in the embodiment has high
durability and can surely improve efficiency of the refrigeration
circuit.
[0057] In particular, in the compressor, in the fourth front
housing 11d, the first and second communication paths 39a and 39b
are formed in the axial direction of the housing 1. Therefore, in
the compressor, even if the first and second communication paths
39a and 39b are provided to cause the first chamber 29a and the
second chamber 29b to communicate with each other, it is possible
to reduce a body diameter of the compressor. Further, in the
compressor, the guide wall 41 is formed in the fourth front housing
11d. Therefore, in the compressor, it is possible to suitably guide
the intermediate pressure refrigerant to the first and second
communication paths 39a and 39b while suitably preventing the
intermediate pressure refrigerant from directly flowing into the
second suction port 37 after flowing into the first chamber 29a
from the intermediate pressure port 31.
[0058] Further, in the compressor, since both of the first impeller
7 and the second impeller 9 have diameters smaller than the inner
diameter of the motor chamber 29, it is possible to reduce the body
diameter. Further, in the compressor, the first impeller 7 and the
second impeller 9 are arranged with the large diameter portions 7a
and 9a faced to each other. Therefore, in the compressor, a first
thrust force generated on the first impeller 7 side and a second
thrust force generated on the second impeller 9 side act to offset
each other. A resultant force of the first and second thrust forces
decreases. Therefore, in the compressor, it is possible to adopt
the first and second thrust foil bearings 53a and 53b small in size
and increase durability.
[0059] The present invention is explained above according to the
embodiment. However, the present invention is not limited to the
embodiment. It goes without saying that the present invention can
be changed and applied as appropriate without departing from the
gist of the present invention.
* * * * *