U.S. patent application number 12/335860 was filed with the patent office on 2009-06-25 for motor-driven compressor.
Invention is credited to Hiroshi Fukasaku, Masao IGUCHI, Masahiro Kawaguchi, Tatsushi Mori, Ken Suitou.
Application Number | 20090162222 12/335860 |
Document ID | / |
Family ID | 40460911 |
Filed Date | 2009-06-25 |
United States Patent
Application |
20090162222 |
Kind Code |
A1 |
IGUCHI; Masao ; et
al. |
June 25, 2009 |
MOTOR-DRIVEN COMPRESSOR
Abstract
A compressor includes a housing having an inlet port, a
compression mechanism for compression of refrigerant introduced via
the inlet port into the housing, a motor having a stator core and a
coil, an inverter for driving the motor, and a rotary shaft rotated
by the motor thereby to drive the compression mechanism. The
compression mechanism, the motor and the inverter are aligned in
the order in the housing in axial direction of the rotary shaft.
The coil has a coil end projecting toward the inverter from the
stator core and being disposed adjacent to an inner peripheral
surface of the housing. The inlet port is located so as to face the
coil end. A recess is formed on the inner peripheral surface of the
housing for communicating with the inlet port. The recess extends
in the axial direction of the rotary shaft toward the inverter
beyond the coil end.
Inventors: |
IGUCHI; Masao; (Kariya-shi,
JP) ; Kawaguchi; Masahiro; (Kariya-shi, JP) ;
Suitou; Ken; (Kariya-shi, JP) ; Mori; Tatsushi;
(Kariya-shi, JP) ; Fukasaku; Hiroshi; (Kariya-shi,
JP) |
Correspondence
Address: |
Locke Lord Bissell & Liddell LLP;Attn: IP Docketing
Three World Financial Center
New York
NY
10281-2101
US
|
Family ID: |
40460911 |
Appl. No.: |
12/335860 |
Filed: |
December 16, 2008 |
Current U.S.
Class: |
417/410.1 |
Current CPC
Class: |
F04C 29/12 20130101;
F04C 18/0215 20130101; F04C 23/008 20130101; F04C 2240/808
20130101 |
Class at
Publication: |
417/410.1 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 18, 2007 |
JP |
P2007-326413 |
Claims
1. A motor-driven compressor, comprising: a housing having an inlet
port; a compression mechanism for compression of refrigerant
introduced via the inlet port into the housing; an electric motor
having a stator core and a coil; an inverter for driving the
electric motor; and a rotary shaft rotated by the electric motor
thereby to drive the compression mechanism, wherein the compression
mechanism, the electric motor and the inverter are aligned in the
order in the housing in axial direction of the rotary shaft, the
coil has a coil end projecting toward the inverter from the stator
core and being disposed adjacent to an inner peripheral surface of
the housing, the inlet port is located so as to face the coil end,
and a recess is formed on the inner peripheral surface of the
housing for communicating with the inlet port and the recess
extends in the axial direction of the rotary shaft toward the
inverter beyond the coil end.
2. The motor-driven compressor according to claim 1, wherein the
recess is formed along the entire circumference of the inner
peripheral surface of the housing.
3. The motor-driven compressor according to claim 2, wherein the
recess overlaps with and extends around an opening of the inlet
port.
4. The motor-driven compressor according to claim 2, wherein the
recess partially faces with a flow space defined between an inner
end surface of the housing and the coil end.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a motor-driven compressor
having a compression mechanism, an electric motor and an inverter
aligned in a housing in axial direction of a rotary shaft of the
compressor.
[0002] Such compressor is disclosed, for example, in Japanese
Unexamined Patent Application Publication No. 2000-291557. The
compressor has a housing assembly (hereinafter referred to as a
housing) composed of a front housing, an intermediate housing and a
rear housing. The compression mechanism of a scroll-type, the motor
and the inverter are aligned in this order in the housing in axial
direction of the rotary shaft of the compressor. The motor is
controlled by the inverter and drives the compression mechanism for
compression of refrigerant gas. A stator of the motor has a coil,
and a rotor of the motor is mounted on the rotary shaft. The front
housing has a refrigerant inlet port at the periphery. The inlet
port is disposed forward of the coil end. In such kind of
compressor, there is a need for reduction of its axial length.
[0003] In another known compressor disclosed in Japanese Unexamined
Patent Application Publication No. 4-80554, the inlet port is
disposed at a position radially facing the coil end. Therefore, the
axial length of the compressor is small, as compared to the case of
the reference No. 2000-291557.
[0004] In the compressor of the reference No. 4-80554 wherein the
inlet port is radially spaced away from the coil end, so that
refrigerant gas flows smoothly from the inlet port into the
housing, but the diameter of the housing is enlarged.
[0005] The present invention is directed to providing a
motor-driven compressor that allows refrigerant gas to flow
smoothly from an inlet port into a housing without enlarging the
diameter of the housing.
SUMMARY OF THE INVENTION
[0006] In accordance with an aspect of the present invention, a
motor-driven compressor includes a housing having an inlet port, a
compression mechanism for compression of refrigerant introduced via
the inlet port into the housing, an electric motor having a stator
core and a coil, an inverter for driving the electric motor, and a
rotary shaft rotated by the electric motor thereby to drive the
compression mechanism. The compression mechanism, the electric
motor and the inverter are aligned in the order in the housing in
axial direction of the rotary shaft. The coil has a coil end
projecting toward the inverter from the stator core and being
disposed adjacent to an inner peripheral surface of the housing.
The inlet port is located so as to face the coil end. A recess is
formed on the inner peripheral surface of the housing for
communicating with the inlet port. The recess extends in the axial
direction of the rotary shaft toward the inverter beyond the coil
end.
[0007] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The features of the present invention that are believed to
be novel are set forth with particularity in the appended claims.
The invention together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
[0009] FIG. 1 is a longitudinal cross-sectional view of a
compressor according to a first embodiment of the present
invention;
[0010] FIG. 2 is a partial enlarged view of a groove of the
compressor of FIG. 1; and
[0011] FIG. 3 is a partial enlarged view of a groove of a
compressor according to a second embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] The following will describe the first embodiment of the
present invention with reference to FIGS. 1 and 2. FIG. 1 Shows a
motor-driven compressor 10 of the first embodiment. The compressor
10 is used in a refrigeration circuit 11 of a vehicle air
conditioner. It is noted that the right-hand side as viewed in FIG.
1 is the front side of the compressor 10 and the left-hand side is
the rear side of the compressor 10.
[0013] Referring to FIG. 1, the refrigeration circuit 11 includes a
condenser C, an expansion valve V and an evaporator E, as well as
the compressor 10. In the refrigeration circuit 11, high-pressure
and high-temperature refrigerant gas discharged from the compressor
10 is cooled and condensed by the condenser C. The flow of the
refrigerant from the condenser C is controlled by the expansion
valve V. The refrigerant from the expansion valve V is evaporated
in the evaporator E. The refrigeration circuit 11 is provided with
a temperature sensor S and a controller CN. The temperature sensor
S detects the temperature of the refrigerant from the evaporator E.
The controller CN is connected to the expansion valve V for
controlling the opening of the expansion valve V in response to a
signal from the temperature sensor S.
[0014] The compressor 10 has a housing assembly 1 (hereinafter
referred to as a housing 1) composed of an intermediate housing 12,
a rear housing 13 and a front housing 14. The intermediate housing
12 is connected at the rear end thereof to the rear housing 13 via
five bolts B1 (only two bolts are shown in FIG. 1), and at the
front end thereof to the front housing 14 via five bolts B2 (only
one is shown).
[0015] The rear housing 13 forms therein a discharge chamber 15.
The rear housing 13 has a discharge port 16 at the rear end. The
discharge chamber 15 is connected via the discharge port 16 to the
condenser C. The intermediate housing 12 has an inlet port 17 at
the periphery thereof adjacent to the front housing 14. The inner
space of the intermediate housing 12 is connected via the inlet
port 17 to the evaporator E. The intermediate housing 12
accommodates therein a compression mechanism 18 and an electric
motor 19 driving the compression mechanism 18 for compressing
refrigerant gas.
[0016] The compression mechanism 18 includes a fixed scroll 20 and
a movable scroll 21. The fixed scroll 20 is mounted on the
intermediate housing 12. The movable scroll 21 is disposed so as to
face the fixed scroll 20 to form a compression chamber 22
therebetween, the volume of which is variable. The movable scroll
21 is coupled to a rotary shaft 23 supported by the intermediate
housing 12.
[0017] The electric motor 19 (hereinafter referred to as the motor
19) includes a rotor 24 and a cylindrical-shaped stator 25. The
rotor 24 is mounted on the rotary shaft 23 for rotation therewith
in the intermediate housing 12. The rotor 24 has a rotor core 241
mounted on the rotary shaft 23 and permanent magnets 242 mounted on
the rotor core 241. The stator 25 has a stator core 251 and a coil
26. The stator core 251 is mounted on an inner peripheral surface
122 of the intermediate housing 12. The coil 26 is wound on the
teeth (not shown in the drawing) of the stator core 251. The coil
26 is located adjacent to the inner peripheral surface 122 of the
intermediate housing 12. In the embodiment, the coil 26 has a
radial clearance H1 of about 1 mm from the inner peripheral surface
122 (see FIG. 2). The coil 26 has coil ends 261 projecting both
forward and rearward from the stator core 251 along the axis L of
the rotary shaft 23.
[0018] The front housing 14 accommodates therein an inverter 30.
The inverter 30 is electrically connected to the motor 19 via a
harness (not shown in the drawing) and supplies power to the motor
19. The inverter 30 includes a circuit board 301 and electronic
components 302 and 303. The circuit board 301 is mounted on the
front housing 14. The electronic components 302 are heat-generating
components such as switching devices, and mounted on one side of
the circuit board 301 adjacent to the intermediate housing 12 while
being in contact with an outer end surface 121 of the intermediate
housing 12. The electronic components 303 are known components such
as electrolytic capacitors, transformers, driver ICs and resistors,
and mounted on the other side of the circuit board 301. In the
embodiment, the compression mechanism 18, the motor 19 and the
inverter 30 are aligned in this order in the housing 1 in the axial
direction of the rotary shaft 23.
[0019] Referring to FIG. 2, the inlet port 17 of the intermediate
housing 12 is located so as to face the coil end 261 projecting
forward from the stator core 251. A groove 31 is formed on the
inner peripheral surface 122 of the intermediate housing 12 along
its entire circumference in facing relation to the coil end 261.
The groove 31 serves as a recess of the present invention. The
groove 31 and the inlet port 17 are formed through the wall of the
intermediate housing 12 so that the groove 31 directly communicates
with the inlet port 17. The width W1 of the groove 31 in the axial
direction of the rotary shaft 23 is larger than the width W2 of the
inlet port 17. A rear end 311 of the groove 31 is positioned
rearward of a rear end 171 of the inlet port 17, and a front end
312 of the groove 31 is positioned forward of a front end 172 of
the inlet port 17. The width W1 of the groove 31 is larger than the
length L1 of the coil end 261. The rear end 311 of the groove 31 is
positioned rearward of a front end of the stator core 251, and the
front end 312 of the groove 31 is positioned forward of a front end
of the coil end 261. The front end 312 of the groove 31 coincides
with an inner end surface 123 of the intermediate housing 12. The
groove 31 thus extends beyond the coil end 261 in the axial
direction of the rotary shaft 23 toward the inverter 30 so that
part of the groove 31 does not face the coil end 261. In the
embodiment, the groove 31 is formed by cutting the inner peripheral
surface 122 with a depth H2 of about 1 to 2 mm that allows
refrigerant gas to flow from the inlet port 17 smoothly and to
spread toward the front end 312 and the rear end 311 of the groove
31. The groove 31 is formed, for example, by rotating a
side-milling cutter in the intermediate housing 12. A flow space 32
defined between the inner end surface 123 of the intermediate
housing 12 and the coil end 261 is formed in the intermediate
housing 12. In the embodiment, the flow space 32 has a length L2 of
about 3 mm as measured in the axial direction of the rotary shaft
23, allowing refrigerant gas to flow smoothly from the inlet port
17 into the flow space 32. The flow space 32 faces the wall of the
intermediate housing 12 of which the outer end surface 121 is in
contact with the electronic components 302, and therefore the
electronic components 302 are cooled via the wall by cool
refrigerant gas flowing through the flow space 32.
[0020] In the above-described compressor 10, when power is supplied
to the motor 19 from the inverter 30, the rotor 24 of the motor 19
is rotated with the rotary shaft 23 thereby to drive the
compression mechanism 18. While the compression mechanism 18 is in
operation, the volume of the compression chamber 22 between the
scrolls 20 and 21 is varied, and refrigerant gas is introduced from
the evaporator E via the inlet port 17 and the groove 31 into the
intermediate housing 12. Since the refrigerant gas flows from the
inlet port 17 spreading toward the front end 312 and the rear end
311 of the groove 81, part of the refrigerant gas flows around the
coil end 261 and into the flow space 32, while the rest of the
refrigerant gas flows directly into the flow space 32. The
refrigerant gas then flows via an inlet passage 27 into the
compression chamber 22 and compressed therein. After being
compressed, the refrigerant gas is discharged via a discharge
passage 28 into the discharge chamber 15 while pushing open a
discharge valve 29, and flows out of the compressor 10. The
refrigerant then flows through the condenser C, the expansion valve
V and the evaporator E, flowing back into the intermediate housing
12.
[0021] The motor-driven compressor 10 according to the first
embodiment offers the following advantages.
(1) The inlet port 17 of the intermediate housing 12 is disposed at
a position facing the coil end 261 in order to reduce the axial
length of the intermediate housing 12 (or the housing 1). The coil
end 261 (coil 26) is adjacent to the inner peripheral surface 122
of the intermediate housing 12 in order to reduce the diameter of
the intermediate housing 12 (or the housing 1). The groove 31 is
formed on the inner peripheral surface 122 of the intermediate
housing 12 for communicating with the inlet port 17. Since the
groove 31 extends beyond the coil end 261 in the axial direction of
the rotary shaft 23 toward the inverter 30, part of refrigerant gas
flows from the inlet port 17 beyond the coil end 261. As a result,
refrigerant gas flows smoothly from the inlet port 17 into the
intermediate housing 12 with less interfering with the coil end
261. The compressor 10 thus allows refrigerant gas to flow smoothly
from the inlet port 17 into the housing 1 with less enlarging the
axial length and the diameter of the housing 1. (2) The groove 31
is formed along the entire circumference of the inner peripheral
surface 122 of the intermediate housing 12. Therefore, refrigerant
gas smoothly flows from the inlet port 17 into the intermediate
housing 12 through the circumferential space, as compared to a
case, for example, wherein the groove 31 is formed at a position
only adjacent to the inlet port 17. As a result, since refrigerant
gas flowing into the intermediate housing 12 is less affected by
the coil end 261, refrigerant gas flows from the inlet port 17 into
the intermediate housing 12 more smoothly. In addition, the groove
31 can be formed only by rotating a side-milling cutter in the
intermediate housing 12.
[0022] The following will describe the second embodiment of the
present invention with reference to FIG. 3. In FIG. 3, same
reference numbers are used for the common elements or components in
the first and second embodiments, and the description of such
elements or components for the second embodiment will be
omitted.
[0023] Referring to FIG. 3, a groove 50 is formed on the inner
peripheral surface 122 of the intermediate housing 12. A rear end
501 of the groove 50 coincides with the rear end of the inlet port
171, and a front end 502 of the groove 51 is positioned forward of
the front end 172 of the inlet port 17. The Width W3 of the groove
50 in the axial direction of the rotary shaft 23 is larger than the
length L1 of the coil end 261. The rear end 501 of the groove 50 is
positioned forward of the front end of the stator core 251, and the
front end 502 of the groove 50 is positioned forward of the front
end of the coil end 261. The front end 502 of the groove 50
coincides with the inner end surface 123 of the intermediate
housing 12. The groove 50 thus extends beyond the coil end 261 in
the axial direction of the rotary shaft 23 toward the inverter 30
so that part of the groove 51 does not face the coil end 261.
[0024] The second embodiment offers the advantages similar to those
of the first embodiment. The above embodiments may be modified in
various ways as exemplified below.
[0025] In each embodiment, the groove 31 or 50 may be a hole shape
partially formed at the inner peripheral surface 122 of the
intermediate housing 12 so as to communicate with the inlet port
17.
[0026] In each embodiment, the compression mechanism 18 is of a
scroll type having the fixed and movable scrolls 20 and 21, but it
may be of a piston type or a vane type.
[0027] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive, and the invention
is not to be limited to the details given herein but may be
modified within the scope of the appended claims.
* * * * *