U.S. patent application number 13/660155 was filed with the patent office on 2013-05-02 for motor-driven 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 Shingo ENAMI, Ken SUITOU, Tsuyoshi YAMAGUCHI.
Application Number | 20130108486 13/660155 |
Document ID | / |
Family ID | 47146192 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130108486 |
Kind Code |
A1 |
SUITOU; Ken ; et
al. |
May 2, 2013 |
MOTOR-DRIVEN COMPRESSOR
Abstract
A motor-driven compressor includes a housing, an inverter
assembly and an elastic member. The inverter assembly has a base
member, a circuit board and an electronic component. The base
member has a base portion and a sidewall portion that extends from
the base portion toward the housing and is mounted on the housing.
The circuit board is disposed in a space of the base member. The
electronic component is mounted on a surface of the circuit board
adjacent to the housing. The sidewall portion extends beyond an
imaginary plane including the surface of the circuit board. The
elastic member having heat conductivity is located between the
circuit board and the base portion, between the circuit board and
the sidewall portion, and over the surface of the circuit board so
that the circuit board is embedded in the elastic member. A space
is formed between the elastic member and the housing.
Inventors: |
SUITOU; Ken; (Aichi-ken,
JP) ; ENAMI; Shingo; (Aichi-ken, JP) ;
YAMAGUCHI; Tsuyoshi; (Aichi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA TOYOTA JIDOSHOKKI; |
Kariya-shi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Kariya-shi
JP
|
Family ID: |
47146192 |
Appl. No.: |
13/660155 |
Filed: |
October 25, 2012 |
Current U.S.
Class: |
417/410.1 |
Current CPC
Class: |
H02K 11/33 20160101;
F04C 23/008 20130101; H02K 9/22 20130101; F04C 2240/808 20130101;
F04B 39/14 20130101; F04B 39/121 20130101; F04C 18/0215
20130101 |
Class at
Publication: |
417/410.1 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2011 |
JP |
2011-239309 |
Claims
1. A motor-driven compressor comprising: a compression mechanism
compressing a refrigerant; an electric motor driving the
compression mechanism; a housing accommodating the compression
mechanism and the electric motor; an inverter assembly controlling
rotation of the electric motor, the inverter assembly having a base
member, a circuit board and an electronic component, the base
member having a base portion and a sidewall portion that extends
from the base portion toward the housing and is mounted on the
housing, the base member having therein a space, the circuit board
being disposed in the space of the base member, the electronic
component being mounted on a surface of the circuit board adjacent
to the housing, the sidewall portion of the base member extending
beyond an imaginary plane that includes the surface of the circuit
board; and an elastic member having heat conductivity located
between the circuit board and the base portion of the base member,
between the circuit board and the sidewall portion, and also over
the surface of the circuit board so that the circuit board is
embedded in the elastic member, a space being formed between the
elastic member and the housing.
2. The motor-driven compressor according to claim 1, wherein the
electronic component is partly embedded in the elastic member.
3. The motor-driven compressor according to claim 1, wherein the
elastic member is made of a gel material.
4. The motor-driven compressor according to claim 1, wherein the
elastic member has a first layer located between the circuit board
and the base portion of the base member, and a second layer located
between the circuit board and the sidewall portion and also over
the surface of the circuit board.
5. The motor-driven compressor according to claim 1, wherein the
electronic component is in indirect contact with the housing
through a heat conductive member.
6. The motor-driven compressor according to claim 1, wherein the
electronic component is in contact with the housing.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a motor-driven compressor
and more particularly to a motor-driven compressor having an
inverter assembly.
[0002] Generally, a common motor-driven compressor includes a
compression mechanism that compresses a refrigerant, an electric
motor that drives the compression mechanism, and an inverter
assembly that controls rotation of the electric motor. The inverter
assembly has therein a circuit board on which electronic components
of an inverter circuit are mounted.
[0003] Japanese Unexamined Patent Application Publication No.
2004-251161 discloses an inverter assembly that includes a sidewall
portion formed on the surface of the housing of the motor-driven
compressor and a cover member that is provided separately from the
housing. In this Publication wherein a circuit board on which
electronic components are mounted is mounted to the cover member
and then the cover member is joined to the sidewall portion formed
on the surface of the housing, the cover member protects the
electronic components and the circuit board.
[0004] The electronic components and the circuit board, which form
an inverter circuit, are more susceptible to damage than mechanical
or electrical parts such as compression mechanism or electric
motor. During assembling of the motor-driven compressor, foreign
matters such as dust may be attached to or any shock be applied to
the electronic components and the circuit board, thereby inviting
damage.
[0005] Although the above-described inverter assembly of the
Publication may be one solution to the attachment of foreign
matters or the damage to the electronic components and the circuit
board in assembling of the motor-driven compressor, the lead wires
of the electronic components and the surface of the circuit board
remain exposed after the electronic components and the circuit
board have been mounted to the cover member, which makes it
difficult to successfully prevent the attachment of foreign matters
or the damage to the lead wires of the electronic components and
the surface of the circuit board.
[0006] The present invention, which has been made in light of the
above problem, is directed to providing a motor-driven compressor
having an inverter assembly that prevents the attachment of foreign
matters or the damage to the electronic components and the circuit
board in assembling of the motor-driven compressor.
SUMMARY OF THE INVENTION
[0007] In accordance with an aspect of the present invention, there
is provided a motor-driven compressor that includes a compression
mechanism, an electric motor, a housing, an inverter assembly and
an elastic member. The compression mechanism compresses a
refrigerant. The electric motor drives the compression mechanism.
The housing accommodates the compression mechanism and the electric
motor. The inverter assembly controls rotation of the electric
motor. The inverter assembly has a base member, a circuit board and
an electronic component. The base member has a base portion and a
sidewall portion that extends from the base portion toward the
housing and is mounted on the housing. The base member has therein
a space. The circuit board is disposed in the space of the base
member. The electronic component is mounted on a surface of the
circuit board adjacent to the housing. The sidewall portion of the
base member extends beyond an imaginary plane that includes the
surface of the circuit board. The elastic member having heat
conductivity is located between the circuit board and the base
portion of the base member, between the circuit board and the
sidewall portion, and also over the surface of the circuit board so
that the circuit board is embedded in the elastic member. A space
is formed between the elastic member and the housing.
[0008] 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
[0009] 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:
[0010] FIG. 1 is a longitudinal sectional view showing a
motor-driven compressor according to a first embodiment of the
present invention;
[0011] FIG. 2 is a schematic sectional view showing the internal
structure of an inverter assembly of the motor-driven compressor of
FIG. 1;
[0012] FIGS. 3A through 3C are schematic sectional views
illustrating a method of assembling the inverter assembly of the
motor-driven compressor;
[0013] FIG. 3D is a schematic sectional view illustrating a method
of mounting the inverter assembly to a housing of the motor-driven
compressor;
[0014] FIG. 4 is a schematic sectional view showing the internal
structure of an inverter assembly of a motor-driven compressor
according to a second embodiment of the present invention; and
[0015] FIG. 5 is a schematic sectional view showing the internal
structure of an inverter assembly of a motor-driven compressor
according to another embodiment of the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0016] The following will describe the embodiments of the present
invention with reference to the accompanying drawings. Referring to
FIG. 1 showing the motor-driven compressor according to the first
embodiment of the present invention in longitudinal sectional view,
the motor-driven compressor 1 includes a housing 2 that
accommodates a compression mechanism 3 and an electric motor 4. The
compression mechanism 3 compresses a refrigerant R, and the
electric motor 4 drives the compression mechanism 3. The
motor-driven compressor 1 will be referred to merely as
"compressor" 1 hereinafter. The compressor 1 further includes an
inverter assembly 5 mounted on the surface 2A of the housing 2 for
controlling the rotation of the electric motor 4.
[0017] The compressor 1 draws in low-temperature and low-pressure
refrigerant R via an inlet 6 formed in the housing 2 and the
electric motor 4 into the compression mechanism 3 for compression.
Compressed high-temperature and high-pressure refrigerant R is
discharged via an outlet 7 formed in the housing 2 out of the
compressor 1. The inverter assembly 5 is mounted and fastened to
the surface 2A of the housing 2 by any fastening members such as
bolts (not shown) at a position that is adjacent to the passage
through which the low-temperature and low-pressure refrigerant R
flows.
[0018] Referring to FIG. 2 showing the internal structure of the
inverter assembly 5 in schematic sectional view, the inverter
assembly 5 has a base member 8 with a base portion 8A and a
sidewall portion 8B that are made of a heat conductive material
such as aluminum. The sidewall portion 8B extends from the base
portion 8A toward the housing 2. The base member 8 has therein a
space 9 and an insulating sheet 10 that is attached to the bottom
of space 9. The insulating sheet 10 serves to electrically insulate
a circuit board 14 (to be described later) and the base member 8.
The sidewall portion 8B of the base member 8 is joined to an
extension 2B of the housing 2 so that the opening of the space 9
faces the surface 2A.
[0019] The aforementioned circuit board 14 on which electronic
components 11-13 are mounted is disposed in the space 9 of the base
member 8 and fixed by bolts 15 and 16 to projections 8C extending
from the base portion 8A of the base member 8. The electronic
components 11-13 form part of an inverter circuit of the inverter
assembly 5.
[0020] The electronic components 11-13 are electronic elements such
as switching device (e.g. insulated gate bipolar transistor (IGBT)
and so forth), driver IC, capacitor, transformer or coil. The
electronic components 11-13 in operation generate heat. The
electronic components 11-13 are mounted on an upper surface 14A of
the circuit board 14 that faces the surface 2A of the housing 2, as
shown in FIG. 2. The electronic components 11-13 are located across
a heat conductive member 17 from the housing 2, so that the
electronic components 11-13 and the surface 2A of the housing 2 are
in indirect contact with each other through the heat conductive
member 17. The heat conductive member 17 is made of a heat
conductive material such as aluminum.
[0021] An elastic member 18 having heat conductivity is located in
the space 9, or between a lower surface 14B of the circuit board 14
that faces the base portion 8A of the base member 8 and the
insulating sheet 10, between a side surface 14C of the circuit
board 14 and the sidewall portion 8B of the base member 8, and also
over the upper surface 14A of the circuit board 14 so that
lead-wires 11A-13A of the electronic components 11-13 and parts
11B-13B of the electronic components 11-13 adjacent to the circuit
board 14 are embedded in the elastic member 18. Thus, each of the
electronic components 11-13 is partly embedded in the elastic
member 18.
[0022] The elastic member 18 is made of a material that is fluid
initially but cured over time, such as silicone. Fluid silicone is
poured into the space 9 in assembling the inverter assembly 5. The
silicone thus poured is cured over time into a gel having
elasticity.
[0023] The sidewall portion 8B of the base member 8 extends beyond
an imaginary plane that includes the upper surface 14A of the
circuit board 14 and toward the housing 2, so that the poured
silicone or the elastic member 18 is prevented from flowing out of
the space 9 and that a space 19 is formed between the exposed
surface of the poured silicone and the surface 2A of the housing
2.
[0024] In the above-described inverter assembly 5, the heat
generated by the electronic components 11-13 during the operation
of the compressor 1 is transferred to the surface 2A of the housing
2 via the heat conductive member 17. In the present embodiment
wherein the inverter assembly 5 is mounted on the surface 2A
adjacent to the passage through which low-temperature and
low-pressure refrigerant R drawn into the compression mechanism 3
flows, the heat transferred to the surface 2A of the housing 2 is
radiated from the surface 2A. The heat transferred from the
electronic components 11-13 to the circuit board 14 is further
transferred to the base member 8 via the elastic member 18 covering
the entire area of the circuit board 14. Thus, the heat is also
radiated from the base member 8.
[0025] The following will describe in detail a method of assembling
the inverter assembly 5 and a method of mounting the inverter
assembly 5 on the housing 2, with reference to FIGS. 3A through 3D.
To begin with, the insulating sheet 10 is attached to the bottom of
the space 9 of the base member 8, as shown in FIG. 3A. The circuit
board 14 having the electronic components 11-13 is then fixed to
the projections 8C of the base member 8 by bolts 15 and 16, as
shown in FIG. 3B. Subsequently, fluid silicone is poured into the
space 9 so as to be filled between the lower surface 14B of the
circuit board 14 and the insulating sheet 10, between the side
surface 14C of the circuit board 14 and the sidewall portion 8B of
the base member 8, over the upper surface 14A of the circuit board
14, and also over the parts 11B-13B of the electronic components
11-13, as shown in FIG. 3C. The poured silicone is allowed to cure
over time into a gel state. Since the sidewall portion 8B of the
base member 8 extends beyond the imaginary plane that includes the
upper surface 14A of the circuit board 14 and toward the housing 2,
the poured silicone is prevented from flowing out of the space 9.
After the silicone becomes cured into an elastic gel, the base
member 8 is joined at the sidewall portion 8B thereof to the
extension 2B of the housing 2, as shown in FIG. 3D. Thus, the
inverter assembly 5 is mounted on the housing 2.
[0026] As described above, in the inverter assembly 5 of the
compressor 1 according to the first embodiment, the elastic member
18 having heat conductivity is located between the lower surface
14B of the circuit board 14 and the insulating sheet 10, between
the side surface 14C of the circuit board 14 and the sidewall
portion 8B of the base member 8, over the upper surface 14A of the
circuit board 14, and also over the parts 11B-13B of the electronic
components 11-13. The electronic components 11-13 and the circuit
board 14 are covered by the elastic member 18 before the inverter
assembly 5 is mounted on the housing 2 in the assembling of the
compressor 1. Therefore, attachment of foreign matters to the
electronic components 11-13 and to the circuit board 14 during the
assembling of the compressor 1 is prevented. The circuit board 14
and the parts 11B-13B of the electronic components 11-13 which are
embedded in the elastic member 18 offer good resistance against the
shock encountered in mounting the inverter assembly 5 on the
housing 2. In addition, since the vibration transmitted from the
compression mechanism 3 is absorbed by the elastic member 18 during
the operation of the compressor 1, the damage to the electronic
components 11-13 and the circuit board 14 is prevented.
[0027] The elastic member 18 is not provided throughout the entire
space defined by the base member 8 and the housing 2, but the
aforementioned space 19 is formed between the elastic member 18 and
the surface 2A of the housing 2. Thus, the inverter assembly 5
needs only less amount of silicone for the elastic member 18 and,
therefore, the time for the silicone to be cured and hence the time
for assembling the inverter assembly 5 is shortened. If the elastic
member 18 is provided throughout the entire space defined by the
base member 8 and the housing 2, air holes need to be formed in the
base member 8 against the pressure change in the space defined by
the base member 8 and the housing 2 due to a rise of its
temperature. In the first embodiment wherein the pressure change is
absorbed by the space 19, however, it is not necessary to take such
measures.
[0028] The following will describe the inverter assembly 205 of the
motor-driven compressor according to the second embodiment of the
present invention with reference to FIG. 4. In FIG. 4, same
reference numerals of FIG. 2 are used for elements or components
that are similar to their counterparts in the inverter assembly 5
of the compressor 1 according to the first embodiment, and the
description of such elements or components for the second
embodiment will be omitted.
[0029] In the inverter assembly 205 of the second embodiment, a
first layer made of a material that is a gel in its initial state,
such as .alpha.GEL (registered trademark), is used as an elastic
member 220 located between the lower surface 14B of the circuit
board 14 and the insulating sheet 10. In addition, a second layer
made of a material that is fluid in its initial state as in the
first embodiment is used as the elastic member 18 located between
the side surface 14C of the circuit board 14 and the sidewall
portion 8B of the base member 8 and also over the upper surface 14A
of the circuit board 14.
[0030] In assembling the inverter assembly 205, the insulating
sheet 10 and the elastic member 220 are formed at the bottom of the
space 9 and then the circuit board 14 is fixed to the projections
8C of the base member 8, as shown in FIG. 4. A material that is
fluid initially such as silicone is poured onto the upper surface
14A and the side surface 14C of the circuit board 14.
[0031] The inverter assembly 205 of the second embodiment that uses
the first layer made of a material that is a gel in its initial
state as the elastic member 220 disposed over the lower surface 14B
of the circuit board 14 needs only less amount of the elastic
member 18 than the inverter assembly 5 of the first embodiment.
Thus, the elastic member 18 of the inverter assembly 205 needs only
a shorter time to be cured than the elastic member 18 of the
inverter assembly 5, so that the time taken to assemble the
inverter assembly 205 is reduced.
[0032] Although in the first and second embodiments the electronic
components 11-13 mounted on the circuit board 14 are in indirect
contact with the surface 2A of the housing 2 through the heat
conductive member 17, the electronic components 11-13 may be
arranged in contact with the surface 302A of the housing 302, as
shown in FIG. 5.
[0033] In the first embodiment, the inverter assembly 5 may
dispense with the insulating sheet 10 and the bolts 15 and 16 by
making the elastic member 18 of a material having sufficient
insulating property and strength. In the second embodiment, the
inverter assembly 205 may dispense with the insulating sheet 10 and
the bolts 15 and 16 by making the elastic member 220 of a material
having sufficient insulating property and the elastic member 18 of
a material having sufficient strength and adhesion.
* * * * *