U.S. patent application number 11/040760 was filed with the patent office on 2005-07-28 for compressor.
Invention is credited to Fujii, Toshiro, Hoshino, Tatsuyuki, Suzuki, Fumihiro.
Application Number | 20050163630 11/040760 |
Document ID | / |
Family ID | 34792426 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163630 |
Kind Code |
A1 |
Hoshino, Tatsuyuki ; et
al. |
July 28, 2005 |
Compressor
Abstract
A compressor includes a housing member having a through hole.
The compressor includes a conductive portion through which external
electricity is supplied to a motor mechanism. The conductive
portion has a lead extending from the motor mechanism, and a
connector terminal. The connector terminal is connected to the lead
to permit the external electricity to be conducted to the lead. The
connector terminal is attached to the through hole such that a
joint between the lead and the connector terminal is located in the
through hole to face inward of the housing member. A viscoelastic
insulating material fills the through hole. Therefore, the
compressor ensures reliable insulation of the terminal from a
housing member.
Inventors: |
Hoshino, Tatsuyuki;
(Kariya-shi, JP) ; Fujii, Toshiro; (Kariya-shi,
JP) ; Suzuki, Fumihiro; (Kariya-shi, JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
3 World Financial Center
New York
NY
10281-2101
US
|
Family ID: |
34792426 |
Appl. No.: |
11/040760 |
Filed: |
January 20, 2005 |
Current U.S.
Class: |
417/410.3 ;
417/310 |
Current CPC
Class: |
F04C 29/0085 20130101;
F04C 18/0215 20130101; F05C 2225/00 20130101; F05C 2253/20
20130101; F04C 2230/60 20130101; F05C 2251/02 20130101; F01C 21/10
20130101; F05C 2203/06 20130101 |
Class at
Publication: |
417/410.3 ;
417/310 |
International
Class: |
F04B 049/00; F04B
017/00; F04B 035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 23, 2004 |
JP |
2004-015163 |
Claims
1. A compressor, comprising: a housing member forming a shell of
the compressor, the housing member having a through hole; a
compression mechanism for compressing drawn gas; a motor mechanism
for driving the compression mechanism; a conductive portion through
which external electricity is supplied to the motor mechanism, the
conductive portion having a lead extending from the motor
mechanism, and a connector terminal, the connector terminal being
connected to the lead to permit the external electricity to be
conducted to the lead, wherein the connector terminal is attached
to the through hole such that a joint between the lead and the
connector terminal is located in the through hole to face inward of
the housing member; and a viscoelastic insulating material filling
the through hole.
2. The compressor according to claim 1, wherein the joint is
located inward of the connector terminal in the housing member.
3. The compressor according to claim 1, wherein the connector
terminal is fixed to the housing member to block the through hole
from the outside of the housing member.
4. The compressor according to claim 1, further comprising a
sealing member located between the connector terminal and the
housing member.
5. The compressor according to claim 1, wherein the joint is buried
in the viscoelastic insulating material.
6. The compressor according to claim 1, wherein the viscoelastic
insulating material is an elastic silicone resin.
7. The compressor according to claim 1, wherein the viscoelastic
insulating material fills an inward portion of the through hole in
the housing member, and wherein a dissimilar insulating material
that is different from the viscoelastic insulating material fills a
space between the connector terminal and the viscoelastic
insulating material in the through hole.
8. The compressor according to claim 7, wherein the joint is buried
in the dissimilar insulating material.
9. The compressor according to claim 7, wherein the dissimilar
insulating material is a cured resin.
10. The compressor according to claim 1, wherein the connector
terminal is a hermetic terminal.
11. The compressor according to claim 1, wherein the connector
terminal has a cap body that blocks an outer opening of the through
hole at the outer surface of the housing member, and wherein the
joint is located between the cap body and an inner opening of the
through hole in the housing member.
12. The compressor according to claim 11, wherein the diameter of
the outer opening of the through hole is greater than the diameter
of the remainder of the through hole, and wherein the cap body is
accommodated in the outer opening of the through hole.
13. The compressor according to claim 11, further comprising a
sealing member located between the cap body and a circumferential
surface of the through hole.
14. The compressor according to claim 11, wherein the viscoelastic
insulating material blocks the inner opening of the through hole,
and wherein a dissimilar insulating material that is different from
the viscoelastic insulating material fills a space between the cap
body and the viscoelastic insulating material in the through
hole.
15. The compressor according to claim 1, wherein the housing member
has at least one of an inner boss projecting inward from an area
around an inner opening of the through hole and an outer boss
projecting outward from an area around an outer opening of the
through hole.
16. A compressor, comprising: a housing member forming a shell of
the compressor, the housing member having a through hole; a
compression mechanism for compressing drawn gas; a motor mechanism
for driving the compression mechanism; a conductive portion through
which external electricity is supplied to the motor mechanism, the
conductive portion having a lead extending from the motor
mechanism, and a connector terminal, the connector terminal being
connected to the lead to permit the external electricity to be
conducted to the lead, wherein the connector terminal has a cap
body that blocks an outer opening of the through hole at the outer
surface of the housing member, and a pin that extends through the
cap body and is connected to the lead, and wherein the joint is
located between the cap body and an inner opening of the through
hole in the housing member; and a viscoelastic insulating material
filling the through hole.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a compressor, and more
particularly, to a compressor that has a terminal for conducting
external electricity to a motor mechanism accommodated in a housing
member.
[0002] FIG. 6 shows a conventional compressor 90 having such a
terminal. The compressor 90 includes a plurality of housing members
91, 92, 93 forming a shell of the compressor 90, a compression
mechanism 94 for compressing drawn gas (air), a motor mechanism 95
for driving the compression mechanism 94, and a conductive portion
96 through which external electricity is supplied to the motor
mechanism 95. The compression mechanism 94 and the motor mechanism
95 are accommodated in the housing members 91 to 93. The conductive
portion 96 conducts external electricity to the motor mechanism 95.
Accordingly, the motor mechanism 95 drives the compression
mechanism 94.
[0003] The conductive portion 96 includes leads 97 connected to the
motor mechanism 95 and a terminal 98 that contacts the leads 97. A
through hole 93a is formed in the housing member 93. The terminal
98 is press fitted in the through hole 93a. A joint 99 between the
terminal 98 and the leads 97 is buried in epoxy resin P, which is
an insulating material. The epoxy resin P, in which the joint 99
between the terminal 98 and the leads 97 is buried, is first in a
liquid state, but is hardened as time elapses. The hardened epoxy
resin P improves the insulating performance of the terminal 98 and
the leads 97, thereby preventing leakage of current in the
electrical system (for example, refer to Japanese Laid-Open Patent
Publication No. 6-235388).
[0004] In the above described prior art, operation of the
compressor 90 increases the temperature of the compressor 90. When
the operation is stopped, the temperature of the compressor 90
drops. As the temperature of the compressor 90 is increased and
lowered, portions of the compressor (for example, the housing
members 91 to 93) are heated and cooled. Accordingly, the portions
of the compressor expand and shrink.
[0005] Expansion and shrinkage of the portions of the compressor 90
are dominated by the thermal expansion coefficient of the materials
forming the portions. Since the thermal expansion coefficient of
the housing members 91 to 93 is different from that of the epoxy
resin P, minute spaces can be created between the contacting
surfaces of the housing member 93 and the epoxy resin P when the
compressor 90 is cooled and the portions shrink. Also, since the
thermal expansion coefficient of the epoxy resin P is different
from that of the leads 97, minute spaces can be created between the
contacting surfaces of the leads 97 and the epoxy resin P.
[0006] When water is caught inside the housing members 91 to 93,
the water can enter the minute spaces due to capillarity. If the
water reaches the joint between the terminal 98 and the leads 97,
the insulation of the terminal 98 can deteriorate.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an objective of the present invention to
provide a compressor that ensures reliable insulation of a terminal
from a housing member.
[0008] To achieve the above-mentioned objective, the present
invention provides a compressor. The compressor includes a housing
member forming a shell of the compressor. The housing member has a
through hole. A compression mechanism compresses drawn gas. A motor
mechanism drives the compression mechanism. The compressor includes
a conductive portion through which external electricity is supplied
to the motor mechanism. The conductive portion has a lead extending
from the motor mechanism, and a connector terminal. The connector
terminal is connected to the lead to permit the external
electricity to be conducted to the lead. The connector terminal is
attached to the through hole such that a joint between the lead and
the connector terminal is located in the through hole to face
inward of the housing member. A viscoelastic insulating material
fills the through hole.
[0009] 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
[0010] 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:
[0011] FIG. 1 is a cross-sectional view illustrating a compressor
according to a first embodiment of the present invention;
[0012] FIG. 2 is a cross-sectional view illustrating a part of the
compressor shown in FIG. 1;
[0013] FIG. 3 is a perspective view illustrating a hermetic
terminal of the compressor shown in FIG. 1;
[0014] FIG. 4 is a cross-sectional view illustrating a part of a
compressor according to a second embodiment of the present
invention;
[0015] FIGS. 5(a) to 5(c) are cross-sectional views illustrating
first to third modifications of the through hole shown in FIG. 2;
and
[0016] FIG. 6 is a cross-sectional view showing a prior art
compressor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] A compressor 10 according to a first embodiment of the
present invention will now be described with reference to FIGS. 1
to 3. The compressor 10 of this embodiment is a scroll compressor
and is categorized in the field of hermetic electric compressors.
Specifically, the compressor 10 is a scroll compressor for a fuel
cell (hereinafter, simply referred to as a compressor). FIG. 1
illustrates an example of the compressor 10.
[0018] The compressor 10 shown in FIG. 1 is mainly composed of a
compression mechanism, a drive mechanism, and a motor mechanism,
and sends compressed air to an oxygen electrode of a fuel cell.
[0019] The compression mechanism of the compressor 10 includes a
fixed scroll 11, an orbiting scroll 12, and compression chambers 13
defined by the fixed scroll 11 and the orbiting scroll 12. The
fixed scroll 11 has a disk-shaped fixed base plate 11a, a spiral
fixed wrap 11b projecting from the fixed base plate 11a, and an
outermost wall 11c of the fixed wrap 11b. The fixed base plate 11a
and the fixed wrap outermost wall 11c form a fixed scroll housing
member 16. The fixed scroll housing member 16 forms a part of the
shell of the compressor 10. In this embodiment, the fixed scroll
housing member 16 is made of an aluminum based metal material to
reduce the weight of the compressor 10.
[0020] A suction passage 14 for conducting air into the compression
chambers 13 is formed in the fixed scroll housing member 16. A
discharge passage 15 is formed in the center of the fixed base
plate 11a. The discharge passage 15 is connected to an oxygen
electrode of the fuel cell through a discharge pipe.
[0021] The orbiting scroll 12 includes a disk-shaped orbiting base
plate 12a and a spiral orbiting wrap 12b protruding from the
orbiting base plate 12a. A cup-shaped main support portion 12c for
holding a roller bearing 17 is formed in the center of the orbiting
base plate 12a at the rear side. Three cup-shaped subordinate
support portions 12d (only one of them is shown in FIG. 1) are
formed in a peripheral portion of the orbiting base plate 12a. The
subordinate support portions 12d are provided at equal intervals.
Each subordinate support portion 12d support a radial ball bearing
18.
[0022] The driving mechanism of the compressor 10 includes a
driving crank mechanism 19 for causing the orbiting scroll 12 to
orbit, and a follower crank mechanism 20 for preventing the
orbiting scroll 12 from rotating, and a crank chamber 21 for
accommodating the crank mechanisms 19, 20. The crank chamber 21 is
connected to the suction passage 14, and the crank chamber 21 is
filled with air drawn through the suction passage 14. The driving
crank mechanism 19 includes the main support portion 12c, a crank
pin 22a of a drive shaft 22, and the roller bearing 17 that
supports the crank pin 22a. The follower crank mechanism 20
includes the subordinate support portions 12d and the radial ball
bearings 18 that support crank pins 23a of follower shafts 23. The
rear side of the follower shafts 23 is supported by ball bearings
23c.
[0023] To cancel moment of inertial generated by orbiting motion of
the orbiting scroll 12, balance weights 22b, 22c, 22d are provided
on the drive shaft 22, and a balance weight 23b is provided on each
follower shaft 23. This reduces vibration.
[0024] The motor mechanism includes a center housing member 24, a
rear housing member 25 fixed to the center housing member 24 with
bolts, a motor chamber 27 located between the housing members 24
and 25, and a drive motor 26. The drive motor 26 is accommodated in
the motor chamber 27. The drive motor 26 is a synchronous motor
that includes the drive shaft 22 that extends through a center of
the motor 26, a rotor 28 fitted around the drive shaft 22, and a
stator 30, around which a coil 29 is wound. The performance of the
drive motor 26, for example, rotation speed, is therefore
controllable with an unillustrated inverter. The coil 29 of the
motor 26 is connected to a conductive portion 33. External
electricity is supplied to the drive motor 26 through the
conductive portion 33.
[0025] A front portion of the drive shaft 22 is supported by a ball
bearing 22e. The drive shaft 22 is also supported by a ball bearing
22f at a center portion of the rear housing member 25. The rear end
of the drive shaft 22 is sealed with a seal 22g.
[0026] Further, the center housing member 24, which covers the
drive motor 26, has a water jacket 31, the position of which
corresponds to the position of the stator 30. Coolant is conducted
to the water jacket 31 to cool the drive motor 26. The center
housing member 24 and the rear housing member 25 coupled to the
center housing member 24 are housing members forming a part of the
shell of the compressor 10 together with the fixed scroll housing
member 16. In this embodiment, the center housing member 24 and the
rear housing member 25 are made of an aluminum based metal material
to reduce the weight of the compressor 10.
[0027] The motor mechanism is accommodated in the center housing
member 24 together with the drive mechanism. A support frame 32 is
integrally formed with the center housing member 24 substantially
at the center to separate the drive mechanism and the motor
mechanism from each other. The ball bearing 22e and the ball
bearings 23c are fitted in the support frame 32. The support frame
32 separates the drive mechanism and the motor mechanism from each
other except for a space between the circumferential surface of the
drive shaft 22 and the ball bearing 22e and a space between the
circumferential surface of each follower shaft 23 and the
corresponding ball bearing 23c.
[0028] The conductive portion 33 of the motor mechanism will now be
described.
[0029] It has already been described above that the conductive
portion 33 functions to conduct external electricity to the drive
motor 26. The conductive portion 33 of this embodiment includes
leads 34 and a hermetic terminal 35 as shown in FIG. 2. Each lead
34 is covered with an insulating coating 34a and is electrically
connected to the coil 29 of the drive motor 26. The hermetic
terminal 35 functions as a connector terminal. A first end of each
lead 34 is connected to the coil 29, and a second end is engaged
with the hermetic terminal 35. The hermetic terminal 35 permits
electricity to be supplied to the leads 34 and insulates the leads
34 from the center housing member 24. In this embodiment, a through
hole 40 is formed in the center housing member 24. The hermetic
terminal 35 is fitted in the through hole 40 from the outside of
the compressor 10. An attachment portion 40a is formed at an outer
portion of the through hole 40. The diameter of the attachment
portion 40a is greater than the remaining portion of the through
hole 40 so that the hermetic terminal 35 is easily fitted to the
through hole 40.
[0030] As shown in FIG. 3, the hermetic terminal 35 includes a
disk-shaped cap body 36 that is attached to the through hole 40 of
the center housing member 24. As shown in FIG. 2, an annular groove
36a is formed in the circumferential surface of the cap body 36. A
sealing member, which is an O-ring 37, is attached to the groove
36a. Three insertion holes 36b, 36c, 36d are formed in the cap body
36. A terminal pin 38 is inserted in each of the insertion holes
36b, 36c, 36d. A glass member 39 is provided in each of the
insertion holes 36b, 36c, 36d to fill the space around the
corresponding terminal pin 38. The glass member 39 insulates the
terminal pins 38 from the cap body 36 and seals the insertion holes
36b, 36c, 36d.
[0031] The hermetic terminal 35 constructed as described is
attached to the attachment portion 40a of the through hole 40. The
hermetic terminal 35 is attached to the attachment portion 40a to
seal the center housing member 24 with the O-ring 37 attached to
the cap body 36.
[0032] When the hermetic terminal 35 is attached to the through
hole 40, each terminal pin 38 includes an outer end 38a protruding
outward from the center housing member 24 and an inner end 38b
extending inward of the center housing member 24 from the cap body
36. The outer ends 38a of the terminal pins 38 are located outside
of the center housing member 24. The outer ends 38a is connected to
an external power supply with an unillustrated connector. The inner
ends 38b of the terminal pins 38 are located inside the through
hole 40. Each inner end 38b is connected to one of the leads 34,
which are connected to the coil 29 of the drive motor 26.
Therefore, the joints 41 between the terminal pins 38 and the inner
ends 38b are located inside the through hole 40. In other words,
the hermetic terminal 35 is fitted in the through hole 40 such that
the joints 41 between the leads 34 and the hermetic terminal 35 are
located in the through hole 40 while facing inward of the center
housing member 24. Portions of each lead 34 except the joint 41 are
covered with the insulating coating 34a.
[0033] In this embodiment, a portion of the through hole 40 that is
located inward of the attachment portion 40a is filled with a
viscoelastic insulating material M. The insulating material M fills
the through hole 40 of the center housing member 24. Therefore, the
insulating material M filling the through hole 40 buries the joints
41 between the hermetic terminal 35 and the leads 34. A material
having viscoelasticity is viscous to an object that contacts the
material and elastic to external force. Specifically, the
viscoelastic insulating material M in this embodiment is an elastic
silicone resin, which is viscous to objects that contact the resin
and elastic to external force. The elastic silicone resin is first
in a liquid state, but gradually hardened as it is exposed to air.
When hardened, the elastic silicone resin has a certain
viscoelasticity. The insulating material M is injected into the
through hole 40 from the inside of the center housing member
24.
[0034] Operation of the compressor 10 of this embodiment will now
be described.
[0035] When the compressor 10 is driven, drawn air is compressed in
the compression chambers 13. The compressed air is discharged
through the discharge passage 15. Heat generated due to compression
of drawn air increases the temperature of the compressor 10. When
stopped in a heated state, the compressor 10 is cooled. As the
compressor 10 is cooled, portions of the compressor 10 shrink as a
result of cooling. At this time, the center housing member 24 also
shrinks and tends to narrow the through hole 40. The viscoelastic
insulating material M that fills the through hole 40 also shrinks
to reduce the volume. The degrees of shrinkage of the center
housing member 24 and the viscoelastic insulating material M are
different according to the thermal expansion coefficient of the
components forming the center housing member 24 and the material M.
In general, it is known that resin (viscoelastic insulating
material M) has a greater thermal expansion coefficient. Therefore,
at contacting surfaces between the center housing member 24 and the
insulating material M, the center housing member 24 and the
insulating material M tend to separate from each other due to
shrinkage from cooling.
[0036] However, since the insulating material M filling the through
hole 40 has viscoelasticity, the insulating material M keeps
contacting the center housing member 24 even if the thermal
expansion coefficient is different between the center housing
member 24 and the material M. That is, the elasticity of the
insulating material M accommodates the difference in shrinkage
between the center housing member 24 and the insulating material M,
and the viscosity of the insulating material M keeps the adhesion
between the center housing member 24 and the insulating material M.
Therefore, no space is created between the center housing member 24
and the insulating material M, and sealed state is maintained. At
contacting surfaces between the leads 34 and the insulating
material M also, no space is created, and a sealed state is
maintained.
[0037] In this manner, the sealing state is maintained for members
contacting the insulating material M. Thus, even if water is caught
inside the center housing member 24, the water is prevented from
reaching the joints 41 between the hermetic terminal 35 and the
leads 34. Accordingly, the hermetic terminal 35 is maintained as
insulated from the center housing member 24.
[0038] It has already been described above that the temperature of
the compressor 10 is increased as the compressor 10 is driven.
Thermal expansion varies among portions of the compressor 10.
Thermal expansion of the center housing member 24, the hermetic
terminal 35, and the leads 34, which contact the insulating member
M, is accommodated by the insulating material M. The insulating
material M therefore maintains adhesion to the center housing
member 24, the hermetic terminal 35, and the leads 34.
[0039] Thus, even if the temperature of the compressor 10 is
increased, water inside the center housing member 24 does not reach
the joints 41 between the hermetic terminal 35 and the leads
34.
[0040] Further, since the insulating material M has
viscoelasticity, the insulating material M absorbs vibration of the
compressor 10 during operation. Thus, space is not created in the
contacting surfaces of the center housing members 24, the hermetic
terminal 35, and the leads 34, which contact the insulating
material M.
[0041] The O-ring 37, which functions as a sealing member, is
attached to the circumferential surface of the cap body 36 of the
hermetic terminal 35. The O-ring 37 maintains the sealed state of
the through hole 40. Therefore, water that tends to enter the
through hole 40 from the outside of the center housing member 24,
is blocked by the O-ring 37.
[0042] The compressor 10 according to this embodiment provides the
following advantages.
[0043] (1) The joints 41 between the leads 34 and the hermetic
terminal 35 are buried in the viscoelastic insulating material M.
Therefore, when the compressor 10 is cooled, minute spaces that
tend to be present between the insulating material M and the
housing member (center housing member 24), the leads 34, or the
hermetic terminal 35 are accommodated by the elasticity of the
insulating material M. The viscosity of the insulating material M
causes the contacting surfaces between the insulating material M
and the center housing member 24, the leads 34, or the hermetic
terminal 35 to be adhered to each other. Water is prevented from
entering such contacting surfaces.
[0044] (2) The joints 41 between the leads 34 and the hermetic
terminal 35 are buried in the viscoelastic insulating material M.
Therefore, even if portions of the compressor 10 vibrate due to
operation of the compressor 10, the vibration is absorbed by the
viscoelasticity of the insulating material M. Thus, no minute
spaces are created in the contacting surfaces between the
insulating material M and the center housing member 24, the leads
34, or the hermetic terminal 35.
[0045] (3) The joints 41 between the leads 34 and the hermetic
terminal 35 are buried in the viscoelastic insulating material M.
Thus, when the insulating material M receives vibration due to
operation of the compressor 10, cracks are not created. Also, even
if the insulating material M repeatedly receives thermal stress due
to increase and drop of the temperature of the compressor 10, the
insulating material M is not damaged.
[0046] (4) The joints 41 between the leads 34 and the hermetic
terminal 35 are buried in the viscoelastic insulating material M.
Therefore, air inside the center housing member 24 does not leak to
the connector terminal (the hermetic terminal 35) through the
through hole 40 of the center housing member 24.
[0047] (5) The hermetic terminal 35 is attached to the attachment
portion 40a, which is formed at an outer portion of the through
hole 40 with respect to the compressor 10. That is, the hermetic
terminal 35 is fixed to the center housing member 24 to cover the
through hole 40 from the outside. This causes the joints 41 between
the hermetic terminal 35 and the leads 34 to face inward of the
center housing member 24. Therefore, a space is defined in the
through hole 40, which space can be filled with a sufficient amount
of the insulating material M from the inside of the center housing
member 24.
[0048] (6) In this embodiment, the connector terminal that conducts
external electricity and is connected to the leads 34 is the
hermetic terminal 35. Therefore, the leads 34 are insulated from
the center housing member 24 with a relatively simple
structure.
[0049] A compressor 50 according to a second embodiment of the
present invention will now be described.
[0050] The compressor 50 of this embodiment is substantially the
same as the compressor 10 of the previous embodiment, except for
that, together with the viscoelastic insulating material M, an
insulating material N that is different from the material M is
provided. Hereinafter, the material N will sometimes be referred to
as a dissimilar insulating material N for purposes of illustration.
In this embodiment, for purposes of illustration, the entirety of
the compressor 50 is not shown, but part of the compressor 50 is
shown in FIG. 4. Also, some of the reference numerals used in the
first embodiment are given to like or the same components. The
description for such components is omitted here, and the
corresponding description in the first embodiment should be
referred to as necessary.
[0051] In this embodiment, the hermetic terminal 35 is attached to
a through hole 52 formed in a center housing member 51 of the
compressor 50. The joints 41 between the hermetic terminal 35 and
the leads 34 are located inside the through hole 52. In this
embodiment, the two kinds of insulating materials M, N are layered
in the through hole 52. The dissimilar insulating material N is
located between the viscoelastic insulating material M and the
attachment portion 40a.
[0052] The dissimilar insulating material N fills a portion of the
through hole 52 that is inward of the attachment portion 40a and
outward of the insulating material M. The dissimilar insulating
material N is different from the viscoelastic insulating material
M. Specifically, the dissimilar insulating material N is a cured
resin such as an epoxy resin. The dissimilar insulating material N
fills a portion of the through hole 52 that is inward of the
attachment portion 40a and outward of the inner end of the through
hole 52. In other words, the dissimilar insulating material N fills
the through hole 52 in a portion that is inward of the cap body 36
of the hermetic terminal 35, but does not completely fill the
through hole 52. The joints 41 between the terminal pins 38 and the
leads 34 are buried in the dissimilar insulating material N.
[0053] The viscoelastic insulating material M fills a portion of
the through hole 52 that is inward of the dissimilar insulating
material N. In other words, the viscoelastic insulating material M,
together with the dissimilar insulating material N, completely
fills the through hole 52. The viscoelastic insulating material M
only contacts the dissimilar insulating material N, which is a
cured resin, the center housing member 51, and the leads 34
(specifically, the insulating coating 34a).
[0054] In the compressor 50 of this embodiment, the hermetic
terminal 35 attached to the through hole 52 is insulated from the
center housing member 51 by the insulating properties of the
hermetic terminal 35, the dissimilar insulating material N, which
is a cured resin, and the viscoelastic insulating material M. Even
if portions of the compressor 50 shrink due to cooling, the
viscoelastic insulating material M filling an inner portion of the
through hole 52 does not create spaces with, but maintains adhesion
with the dissimilar insulating material N, the center housing
member 51, and the leads 34, which contact the viscoelastic
insulating material M.
[0055] The compressor 50 according to this embodiment provides the
following advantages.
[0056] (1) Since the dissimilar insulating material N and the
viscoelastic insulating material M are used in combination, the
amount of the viscoelastic insulating material M is reduced.
Accordingly, the manufacturing cost of the compressor 50 is
reduced. This advantage is particularly pronounced when the
viscoelastic insulating material M is expensive.
[0057] (2) The dissimilar insulating material N, which is a cured
resin filling a part of the through hole 52, contacts the cap body
36 of the hermetic terminal 35. This reinforces the adhesion of the
hermetic terminal 35 to the center housing member 51.
[0058] A first to third modification of the through hole 40 formed
in a compressor center housing member 24 according to the first
embodiment will now be described with reference to FIGS. 5(a) to
5(c). For purposes of illustration, the same reference numerals are
used for the hermetic terminal 35, the leads 34, and the joints
41.
[0059] A first modification will now be described. As shown in FIG.
5(a), an outer boss 63 is provided around a through hole 62 of a
center housing member 61. The outer boss 63 projects outward of the
center housing member 61. The hermetic terminal 35 is attached to
an outer end of the outer boss 63. A portion of the through hole 62
that is inward of the hermetic terminal 35, or a portion of the
through hole 62 that is inward of the attachment portion 40a, is
filled with the viscoelastic insulating material M.
[0060] A second modification will now be described. As shown in
FIG. 5(b), an inner boss 73 is provided around a through hole 72 of
a center housing member 71. The inner boss 73 projects inward of
the center housing member 71. The hermetic terminal 35 is attached
to an outer end of the through hole 72. A portion of the through
hole 72 that is inward of the hermetic terminal 35, or a portion of
the through hole 72 that is inward of the attachment portion 40a,
is filled with the viscoelastic insulating material M. The
viscoelastic insulating material M fills the through hole 72 to the
end (inner end) of the inner boss 73.
[0061] Lastly, a third modification will be described. As shown in
FIG. 5(c), an outer boss 84 and an inner boss 83 are provided
around a through hole 82 of a center housing member 81. The outer
boss 84 projects outward from the center housing member 81. The
inner boss 83 projects inward from the center housing member 81.
The hermetic terminal 35 is attached to an outer end of the outer
boss 84. A portion of the through hole 82 that is inward of the
hermetic terminal 35, or a portion of the through hole 82 that is
inward of the attachment portion 40a, is filled with the
viscoelastic insulating material M. The viscoelastic insulating
material M fills the through hole 82 to the end (inner end) of the
inner boss 83.
[0062] According to the first to third modifications, the length of
the through hole 62, 72, 82 is elongated by forming at least one of
the outer boss 63, 84 and the inner boss 73, 83 around the through
hole 62, 72, 82, so that a sufficient amount of the viscoelastic
insulating material M fills the through hole 62, 72, 82. In other
words, a space for accommodating a sufficient amount of the
viscoelastic insulating material M is formed. Filling the space
with the insulating material M, the hermetic terminal 35 is further
reliably insulated from the center housing member 61, 71, 81.
Forming at least one of the outer boss 63, 84 and the inner boss
73, 83 facilitates setting of the amount of the viscoelastic
insulating material M according to the conditions in which the
compressor 10 is used. In the first to third modification, the
viscoelastic insulating material M may be used with the dissimilar
insulating material N as described in the second embodiment.
[0063] The invention may be embodied in the following forms.
[0064] In the first and second embodiments, the compressors are
scroll compressors. However, the present invention may be applied
to any form or type of hermetic electric compressor that has a
motor mechanism accommodated in a housing member. For example, the
present invention may be applied to a roots type compressor.
[0065] In the first and second embodiments, an elastic silicone
resin is used as the viscoelastic insulating material M. However,
any resin or rubber material having an insulating property and
viscoelasticity may be used as the insulating material M. In a case
of a compressor connected to a fuel cell, the viscoelastic
insulating material M preferably has acid resistance.
[0066] In the first and second embodiments, the through hole 40 is
formed in the center housing member 24, 51 of the compressor, and
the hermetic terminal 35, which is the connector terminal, is
attached to the through hole 40, 52. However, a housing member to
which the hermetic terminal 35 is attached is not limited to the
center housing member 24, 51. For example, a through hole may be
formed in the rear housing member 25 and the hermetic terminal 35
may be fitted to the through hole. The through hole 40 to which the
hermetic terminal 35 is attached may be formed in any housing
member that forms the shell of the compressor.
[0067] In the first and second embodiments, the O-ring 37, which
functions as a sealing member, is attached to the cap body 36 of
the hermetic terminal 35, which functions as a connector terminal.
However, the sealing member is not limited to the O-ring 37, but
may be any type or shape as long as it has a sealing property.
[0068] 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 and equivalence of the appended claims.
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