U.S. patent application number 12/307122 was filed with the patent office on 2009-11-19 for motor-driven compressor.
Invention is credited to Kazuhiko Kameyama, Masahiko Osaka, Eiichi Oshio, Satoru Saito, Masanori Taguchi, Kou Tsukamoto.
Application Number | 20090285703 12/307122 |
Document ID | / |
Family ID | 38923107 |
Filed Date | 2009-11-19 |
United States Patent
Application |
20090285703 |
Kind Code |
A1 |
Osaka; Masahiko ; et
al. |
November 19, 2009 |
Motor-Driven Compressor
Abstract
An energization bolt (102), which includes an input portion
(102a) to be connected to a motor (40), an intermediate portion
(102b) contiguous to the input portion and positioned in an
insertion hole (23d) formed in a housing (20), and an output
portion (102c) contiguous to the intermediate portion and to be
connected to a drive circuit (98), and energizes between the drive
circuit and the motor, and a seal member (100), which surrounds the
intermediate portion, is sandwiched and supported by the input
portion side and the output portion side, and is fastened to the
housing, are included.
Inventors: |
Osaka; Masahiko; (Gunma,
JP) ; Taguchi; Masanori; (Gunma, JP) ; Saito;
Satoru; (Bad Homburg, DE) ; Oshio; Eiichi;
(Gunma, JP) ; Kameyama; Kazuhiko; (Gunma, JP)
; Tsukamoto; Kou; (Gunma, JP) |
Correspondence
Address: |
COHEN, PONTANI, LIEBERMAN & PAVANE LLP
551 FIFTH AVENUE, SUITE 1210
NEW YORK
NY
10176
US
|
Family ID: |
38923107 |
Appl. No.: |
12/307122 |
Filed: |
June 26, 2007 |
PCT Filed: |
June 26, 2007 |
PCT NO: |
PCT/JP2007/062792 |
371 Date: |
December 30, 2008 |
Current U.S.
Class: |
417/410.1 |
Current CPC
Class: |
H02G 3/22 20130101; F04C
23/008 20130101; F04C 2240/803 20130101; H01R 13/521 20130101; F04C
18/0215 20130101; H02K 5/225 20130101; H02K 5/10 20130101; H02K
7/14 20130101 |
Class at
Publication: |
417/410.1 |
International
Class: |
F04B 35/04 20060101
F04B035/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 12, 2006 |
JP |
2006-191564 |
Claims
1. A motor-driven compressor comprising: a housing which is a
sealed container; a machine chamber formed in the housing, and
provided with a motor whose rotary shaft rotatably supported is
driven by power supply from an external drive circuit; a
compressing unit which is accommodated in the housing, and is
driven by the rotary shaft to perform a series of processes of
suction, compression and discharge of a refrigerant; an
energization bolt which includes an input portion to be connected
to the motor, an intermediate portion contiguous to the input
portion and positioned in an insertion hole formed in the housing,
and an output portion contiguous to the intermediate portion and to
be connected to the drive circuit, and energizes between the drive
circuit and the motor; and a seal member which surrounds the
intermediate portion, is sandwiched and supported by the input
portion side and the output portion side, and is fastened to the
housing.
2. The motor-driven compressor according to claim 1, wherein the
seal member includes an inner block which abuts on an inner end
face of the housing, extends towards inside the housing and has an
insulation property, and an outer block which abuts on an outer end
face of the housing, extends towards outside the housing and has an
insulation property, each of the blocks having a through hole
formed therein to permit insertion of the energization bolt.
3. The motor-driven compressor according to claim 2, wherein the
seal member further includes an intermediate block with an
insulation property, which is surrounded by the inner block and the
outer block, is positioned between the insertion hole and the
intermediate portion, and has a through hole formed therein to
permit insertion of the energization bolt.
4. The motor-driven compressor according to claim 2, wherein an
elastic member which seals the through hole and inside the housing
is disposed between the through hole of the inner block, and the
intermediate portion.
5. The motor-driven compressor according to claim 2, wherein an
elastic member which seals the through hole and inside the housing
is disposed between the inner block and the inner end face of the
housing.
6. The motor-driven compressor according to claim 1, wherein one or
a plurality of energization bolts are provided for each phase of
the motor, and in case of the plurality of energization bolts in
total, the individual energization bolts are disposed adjacent to
one another.
Description
TECHNICAL FIELD
[0001] The present invention relates to a motor-driven compressor,
and, particularly, to a motor-driven compressor suitable to be
incorporated in a refrigeration circuit or the like of the air
conditioning system of a vehicle.
BACKGROUND ART
[0002] This kind of compressor comprises a drive part and
compression part which are accommodated in a housing, and this
compression part is provided with a compressing unit which performs
a series of processes of suction, compression and discharge of a
refrigerant.
[0003] For example, a compressing unit of a scroll type compressor
comprises a fixed scroll and a movable scroll which engage with
each other, and as the movable scroll makes a revolving motion with
respect to a fixed scroll, the volume of the space formed by the
individual scrolls decreases, and the aforementioned series of
processes is carried out. This unit is driven with the rotary
shaft, which is driven by energization of a motor. The rotary shaft
and motor are provided at the drive part, and the terminals of the
motor are electrically connected to the terminals of a drive
circuit disposed outside the compressor via lead wires.
[0004] Here, there is disclosed a technique of directly fastening
the terminals of the motor and the drive circuit by bolts to enable
energization, and eliminating the lead wires therebetween to reduce
electric heat loss (see Japanese Unexamined Patent Publication No.
2002-371983).
[0005] By the way, an insulating measure becomes essential to
supply power to the motor. For this reason, it is desirable to
secure the insulation distance to improve the insulation
performance and reduce portions from which current may leak, as
many as possible. In the conventional technique, however, a
plurality of energization bolts are exposed to a refrigerant or oil
atmosphere, which is not preferable to improve the insulation
performance.
[0006] In addition, to prevent leakage of the refrigerant or oil
atmosphere from the housing, each energization bolt should be
placed in a sealed terminal sealed. However, the conventional
technique needs a fixing part for the sealed terminal to the
housing because of the relationship of the individual energization
bolts spaced apart from one another, those portions and area which
require sealing increase, thus enlarging the sealed terminal
structure and increasing the number of parts, which makes the
assembly work troublesome.
DISCLOSURE OF THE INVENTION
[0007] The present invention has been made in view of such
problems, and it is an object of the invention to provide a
motor-driven compressor which significantly improves the insulation
performance, is compact and has fewer parts, and has sealed
terminals which can be sealed surely.
[0008] To achieve the object, a motor-driven compressor according
to the present invention comprises a housing which is a sealed
container, a machine chamber formed in the housing, and provided
with a motor whose rotary shaft rotatably supported is driven by
power supply from an external drive circuit, a compressing unit
which is accommodated in the housing, and is driven by the rotary
shaft to perform a series of processes of suction, compression and
discharge of a refrigerant, an energization bolt which includes an
input portion to be connected to the motor, an intermediate portion
contiguous to the input portion and positioned in an insertion hole
formed in the housing, and an output portion contiguous to the
intermediate portion and to be connected to the drive circuit, and
energizes between the drive circuit and the motor, and a seal
member which surrounds the intermediate portion, is sandwiched and
supported by the input portion side and the output portion side,
and is fastened to the housing.
[0009] According to the foregoing motor-driven compressor, the
energization bolt is inserted in the insertion hole of the housing,
and the seal member is fastened to the housing only by the
energization bolt. Therefore, the energization bolt serves both to
feed power to the motor from the drive circuit and fix the seal
member, thereby making it unnecessary to separately provide a drive
casing with a fixing portion for the seal member. It is therefore
possible to reduce the number of parts of the motor-driven
compressor and facilitate the assembly work. In addition, the
internal space of the housing can be reduced, making it possible to
promote miniaturization of the motor-driven compressor.
[0010] As a preferable mode, in the motor-driven compressor, the
seal member includes an inner block which abuts on an inner end
face of the housing, extends toward inside the housing and has an
insulation property, and an outer block which abuts on an outer end
face of the housing, extends toward outside the housing and has an
insulation property, each of the blocks having a through hole
formed therein to permit insertion of the energization bolt.
[0011] According to this configuration, the energization bolt and
the inside and outside of the housing can surely be insulated,
making it possible to improve the insulation performance of the
motor-driven compressor.
[0012] As a preferable mode, in the motor-driven compressor, the
seal member further includes an intermediate block with an
insulation property, which is surrounded by the inner block and the
outer block, is positioned between the insertion hole and the
intermediate portion, and has a through hole formed therein to
permit insertion of the energization bolt.
[0013] According to this configuration, the energization bolt and
the insertion hole of the housing can surely be insulated, making
it possible to further improve the insulation performance of the
motor-driven compressor.
[0014] As a preferable mode, in the motor-driven compressor, an
elastic member which seals the through hole and inside the housing
is disposed between the through hole of the inner block, and the
intermediate portion.
[0015] According to this configuration, it is possible to prevent
the refrigerant or oil atmosphere in the housing from leaking
outside the housing through the through hole and the insertion hole
in the axial direction of the energization bolt, making it possible
to improve the sealing performance of the motor-driven
compressor.
[0016] As a preferable mode, in the motor-driven compressor, an
elastic member which seals the through hole and inside the housing
is disposed between the inner block and the inner end face of the
housing.
[0017] According to this configuration, it is possible to prevent
the refrigerant or oil atmosphere in the housing from leaking
outside the housing through the insertion hole in the radial
direction of the energization bolt, making it possible to further
improve the sealing performance of the motor-driven compressor.
[0018] As a preferable mode, in the motor-driven compressor, one or
a plurality of energization bolts are provided for each phase of
the motor, and in case of the plurality of energization bolts in
total, the individual energization bolts are disposed adjacent to
one another.
[0019] According to this configuration, reduction of the internal
space of the housing can be promoted further, thus making it
possible to promote further miniaturization of the motor-driven
compressor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a longitudinal cross-sectional view of a scroll
type compressor according to one embodiment of the present
invention,
[0021] FIG. 2 is a plan view of a seal member in FIG. 1.
[0022] FIG. 3 is an enlarged longitudinal cross-sectional view of
the seal member in FIG. 1.
[0023] FIG. 4 is an enlarged longitudinal cross-sectional view of a
seal member according to a modification of the invention in which
only the positions and the number of O rings to be mounted to the
seal member in FIG. 3 are changed.
BEST MODE FOR CARRYING OUT THE INVENTION
[0024] One embodiment of the present invention will be described
below referring to the drawings.
[0025] FIG. 1 shows a motor-driven compressor 4 according to the
embodiment.
[0026] The motor-driven compressor 4 has a housing 20 extending
horizontally, and is installed into the refrigeration circuit or
the like of the air conditioning system of a vehicle for usage. In
addition to the compressor 4, a gas cooler, an expansion valve, an
evaporator, none shown, and so forth are arranged sequentially in
such a refrigeration circuit, and the compressor 4 sucks a natural
type refrigerant CO.sub.2 refrigerant (simply called refrigerant
hereafter) from the evaporator, compresses this refrigerant, and
discharges the refrigerant toward the gas cooler.
[0027] The housing 20 is a sealed container which comprises a drive
casing 22, a rear casing 23, and a compression casing 24. The drive
casing 22 has both ends open while the compression casing 24 and
the rear casing 23 have cup shapes open to the drive casing 22. The
open ends of the compression casing 24 and the rear casing 23 are
fitted airtightly in the open ends of both ends of the drive casing
22 via bolts 28 and 29. The drive casing 22 and the rear casing 23
may be formed integrally or the individual casings 22, 23, 24 may
be formed integrally if at least one end side is open.
[0028] An annular support block 46 is provided at an open end of
one end side of the drive casing 22. A motor chamber (machine
chamber) 26 is formed in the space between the support block 46 and
the cup-shaped bottomed portion of the rear casing 23 in the drive
casing 22. A stepped rotary shaft 30 is disposed in the motor
chamber 26, and the rotary shaft 30 has a small-diameter shaft part
32 and a large-diameter shaft part 34. The small-diameter shaft
part 32 is rotatably supported by a boss 48 which projects from the
bottomed portion of the rear casing 23 via a needle bearing 38,
while the large-diameter shaft part 34 is rotatably supported at
the support block 46 via a ball bearing 36.
[0029] A suction inlet 25 which communicates with the motor chamber
26 is formed in the peripheral wall of the rear casing 23, and is
connected to the aforementioned evaporator to feed the refrigerant
sucked from the refrigeration circuit into the motor chamber
26.
[0030] The rotary shaft 30 is driven by energization to an electric
motor (motor) 40. Specifically, the electric motor 40 is a
brushless type motor disposed in the motor chamber 26, and
comprises a permanent magnet of a rare earth, such as a neodium
magnet, a rotor 42 fixed to the outer periphery side of the rotary
shaft 30, and a stator 44 which has an armature winding 43 arranged
on the outer periphery side of the rotor 42.
[0031] The electric motor 40 of the embodiment is a three phase
synchronous motor, and power is supplied to the armature winding 43
for each phase as will be described later. As the armature winding
43 is energized, the rotor 42 rotates together with the rotation of
the magnetic field generated by the armature winding 43.
[0032] On the other hand, a scroll unit (compressing unit) 52 is
accommodated in the compression casing 24, and the scroll unit 52
has a movable scroll 54 and a fixed scroll 56. The movable scrolls
54 and the fixed scroll 56 respectively have spiral laps 61 and 79
which engage with each other, and these spiral laps 61 and 79
cooperate together to form a compression chamber 58. The revolving
motion of the movable scroll 54 causes the compression chamber 58
to move toward the center from the radial-directional outer
periphery side of the spiral laps 61, 79, thus reducing the
volume.
[0033] To achieve the revolving motion of the movable scroll 54, an
end plate 60 of the movable scroll 54 has a boss 62 which projects
toward the drive casing 22, and the boss 62 rotatably supports an
eccentric bushing 66 via a needle bearing 64. The eccentric bushing
66 is supported by a crankpin 68, which protrudes eccentrically
from the large-diameter shaft part 34. This causes the movable
scroll 54 to revolve via the crankpin 68 and the eccentric bushing
66 with the rotation of the rotary shaft 30.
[0034] A counter weight 70 is attached to the eccentric bushing 66
between the eccentric bushing 66 and the large-diameter shaft part
34 via a connecting pin 71, and is used as a balance weight at the
time the movable scroll 54 makes a revolving motion.
[0035] On the other hand, the fixed scroll 56 is fixed to the
bottomed portion of the compression casing 24 via a bolt 57, and an
end plate 78 of the fixed scroll 56 partitions the interior of the
compression casing 24 into the compression chamber 58 and a
discharge chamber 80. A discharge hole 82 which communicates with
the compression chamber 58 is formed in the center of the end plate
78, and the discharge hole 82 is opened and closed by a reed valve
84. The reed valve 84 is attached together with its valve guard 86
to the discharge chamber 80 side of the end plate 78.
[0036] Further, an outlet 87 which communicates with the discharge
chamber 80 is formed in the bottomed portion of the compression
casing 24, and the discharge chamber 80 is connected to the
aforementioned gas cooler via the outlet 87, thereby discharging
the compressed refrigerant into the refrigeration circuit.
[0037] By the way, in the compressor 4 of the present embodiment, a
seal member 100 is sandwiched and supported at an end wall 23a of
the cup-shaped rear casing 23 by a bolt 102 (energization
bolt).
[0038] The seal member 100 is structured to include an inner block
104, an outer block 106, and an insulating collar (intermediate
block) 114 which are made of a resin. The inner block 104 abuts on
an inner end face 23b of the end wall 23a of the rear casing 23,
and extends toward the inside of the rear casing 23, i.e., the
inside of the motor chamber.
[0039] On the other hand, the outer block 106 abuts on an outer end
face 23c of the end wall 23a of the rear casing 23, is provided
extending outside the rear casing 23, and is attached facing the
inner block 104 with the end wall 23a inbetween. The insulating
collar 114 is inserted between these inner blocks 104 and outer
block 106, and is surrounded by the blocks 104,106.
[0040] As shown in FIG. 2, as the seal member 100 is seen from the
motor chamber 26 side, an inner end face 104a of the inner block
104 has an approximately triangular shape in a planar view, and
surrounds each bolt 102 to be inserted toward the outer block 106.
The individual bolts 102 are disposed adjacent to one another in
such a way that the distance between the axes of the two adjacent
bolts 102 approaches the diagonal line length of the hexagonal
shape of the head portion of the remaining bolt 102.
[0041] In detail, as shown in FIG. 3, the bolt 102 penetrates
through holes 104b, 106b and 114a formed in the inner and outer
blocks 104, 106, and the insulating collar 114, and is inserted in
an insertion hole bored in the end wall 23a of the rear casing 23.
The individual through holes 104b, 106b, 114a and the individual
insertion holes 23d are provided in correspondence to the three
bolts.
[0042] The bolt 102 has an input portion 102a, an intermediate
portion 102b, and an output portion 102c in order from the motor
chamber 26 side. The input portion 102a is the head portion of the
bolt 102 and is connected with an input terminal member 108 to
which one end of a lead wire 91 is connected.
[0043] The intermediate portion 102b contiguous to the input
portion 102a is a portion which does not have the thread part of
the bolt 102, and its part is positioned in the insertion hole 23d.
The insulation distances between the intermediate portion 102b or
the bolt 102 and the inner end face 23b and the outer end face 23c
of the rear casing 23 are set to the bus line lengths of the inner
and outer blocks 104, 106, respectively.
[0044] The insulating collar 114 has an approximately triangular
shape in a planar view which is approximately similar to the shapes
of the inner and outer blocks 104, 106, and is inserted between the
insertion hole 23d and the intermediate portion 102b, and the bus
line length is set as the insulation distance between the insertion
hole 23d of the rear casing 23 and the bolt 102. In this way, the
intermediate portion 102b of the bolt 102 is surrounded by the seal
member 100.
[0045] The output portion 102c contiguous to the intermediate
portion 102b is positioned at the thread part of the bolt 102 where
the nut 110 is screwed in the bolt 102. Accordingly, an output
terminal member 112 is fastened to the outer end face 106a of the
outer block 106, and at the same time, the inner and outer blocks
104, 106 are fixed to the rear casing 23. Finally, the output
terminal member 112 is connected to one end of a lead wire 90, thus
forming a power supplying circuit.
[0046] In this manner, power is supplied to the armature winding 43
through the lead wire 90, the output terminal member 112, the bolt
102, the input terminal member 108, and the lead wire 91
sequentially from the drive circuit 98 positioned outside the
compressor 4, and the seal member 100 is sandwiched and supported
by the input and output portions 102a and 102c of the bolt 102, and
is fastened to the rear casing 23.
[0047] Procedures of attaching the seal member 100 to the rear
casing 23 will be described below. First, with the bolt 102
inserted in the through hole 104c of the inner block 104
beforehand, the bolt 102 is inserted in the insertion hole 23d of
the rear casing 23. At this time, the inner block 104 and each bolt
102 are united to become a unit.
[0048] Next, the insulating collar 114 is fitted over each bolt 102
projecting out of the rear casing 23 from the insertion hole 23d.
The through hole 114a of the insulating collar 114 is fitted over
the bolt 102 in such a way that the insulating collar 114 is
inserted in the gap between the intermediate portion 102b and
insertion hole 23d.
[0049] Next, the outer block 106 is attached with the through hole
106b being fitted over each bolt 102 from above, and after the
output terminal member 112 is fitted in the output portion 102c,
the nut 110 is screwed on the bolt 102 to fasten the seal member
100 to the end wall 23a of the rear casing 23, thereby completing
the attachment of the seal member 100. The input terminal member
108 and the output terminal member 112 may be formed integral with
the bolt 102.
[0050] An insulation process is performed on the wire connecting
portion from the lead wire 90 to the armature winding 43 through
the lead wire 91, and particularly, the lead wire 91 and the
armature winding 43 are coated with enamel or the like. Further,
the entire input terminal member 108 and the connecting portion of
the input terminal member 108 with the lead terminal 91 are covered
with an insulating tube 116, and the insulating tube 116 is formed
of a heat-shrinkable material, and is engaged with at least one of
the input terminal member 108 and the lead wire 91, though not
illustrated clearly.
[0051] A diameter-reduced portion 104c which has a slight gap to
the intermediate portion 102b is formed in the through hole 104b of
the inner block 104, a groove 104d which is an annular cutaway of
the abutment surface of the rear casing 23 to the inner end face
23b is formed at the diameter-reduced portion 104c, and an O ring
(elastic member) 118 is fitted in the groove 104d.
[0052] The O ring 118 abuts on the inner end face 23b and the
intermediate portion 102b, and seals between the inner end face 23b
side and the outer end face 23c side, i.e., between the inside and
outside of the rear casing 23, and between the inside of the rear
casing 23 and the diameter-reduced portion 104c. In other words,
the through hole 104b is airtightly blocked from the rear casing 23
in both the axial and radial directions of the bolt 102. This O
ring is provided for each bolt 102.
[0053] As shown in FIG. 4, two O rings, namely an O ring 120
(elastic member) which abuts on the inner end face 23b and an O
ring 122 (elastic member) which abuts on the intermediate portion
102b, may be provided. The O ring 122 may abut on the head portion
of the bolt 102 as shown in the diagram, as long as it abuts on the
intermediate portion 102b.
[0054] In the compressor 4 configured in the above manner, when the
electric motor 40 is driven by the power supplied from the drive
circuit 98 to rotate the rotary shaft 30, the movable scroll 54
rotates about the axial center of the fixed scroll 56 via the
eccentric bushing 66. At this time, the rotation of the movable
scroll 54 is prevented by the work of a plurality of rotation block
mechanisms 50. As a result, the movable scroll 54 makes a revolving
motion to the fixed scroll 56 while keeping the revolving state
steady, and the revolving motion sucks the refrigerant into the
compression chamber 58 from the motor chamber 26 through the
suction inlet 25, compresses the sucked refrigerant, and discharges
the compressed refrigerant into the discharge chamber 80.
[0055] The refrigerant in a high-temperature, high-pressure state,
discharged from the discharge chamber 80 passes through the outlet
87 to be cooled within the gas cooler, is supplied to the expansion
valve where it is expanded by the restriction action, and is
ejected into the evaporator, so that the air around the evaporator
is cooled by the evaporation heat of the refrigerant. The cooled
air is sent into the compartment of the vehicle to cool the
interior of a chamber, and air conditioning of the car interior of
the compartment is performed. The refrigerant in the evaporator
returns to the suction inlet 25 of the compressor 4, and is then
compressed again by the compressor 4 to be circulated as described
above.
[0056] According to the embodiment, as described above, the bolt
102 is inserted in the insertion hole 23d bored in the end wall 23a
of the rear casing 23, and the seal member 100 or the inner and
outer blocks 104, 106 are fastened to the end wall 23a only with
the bolts 102. Therefore, the bolt 102 serves to both supply the
power from the drive circuit 98 to the electric motor 40, and fix
the seal member 100, thus eliminating the need for separate
provision of the portion where the seal member 100 is to be fixed
to the end wall 23a. It is therefore possible to reduce the number
of parts of the compressor 4, facilitating the attachment work
thereof, which can reduce the manufacturing cost of the compressor
4.
[0057] What is more, the occupation area of the sealed terminal
becomes smaller to ensure reduction of the space in the rear casing
23, making it possible to promote the miniaturization of the
compressor 4.
[0058] In addition, the inner and outer blocks 104, 106, and the
insulating collar 114 are formed to have an approximately
triangular shape in a planar view, and three bolts 102 are disposed
adjacent to one another. This can promote space reduction in the
rear casing 23 and further the miniaturization of the compressor
4.
[0059] The seal member 100 is structured to include the inner and
outer blocks 104, 106 whose bus line lengths are set to the
insulation distance, and these blocks 104, 106 respectively have
the through holes 104b, 106b which respectively abut on the inner
end face 23b and the outer end face 23c of the end wall 23a of the
rear casing 23 and through which the bolt 102 penetrates.
[0060] The insulating collar 114 whose bus line length is set to be
the insulation distance is inserted between the insertion hole 23d
of the bolt 102, and the intermediate portion 102b of the bolt 102.
Therefore, it is possible to surely insulate the bolt 102, the
inside and outside of the rear casing 23, and the insertion hole
23d of the rear casing 23, so that the insulation performance of
the compressor 4 can be improved significantly.
[0061] Here, the connecting portion of the input terminal member
108 and the lead wire 91 is the charging portion of the electric
motor 40, which is particularly likely to reduce the insulation
performance. While the connecting portion is subjected to an
insulation process beforehand as described above, coverage with the
insulating tube 116 in addition can surely prevent exposure of the
connecting portion, thus making it possible to improve the
reliability in the insulation performance of the compressor 4.
[0062] Since the insulating tube 116 is a heat-shrinkable tube, it
certainly fits to the input terminal member 108 and the
aforementioned connecting portion and is engaged with either one of
the input terminal member 108 or the lead wire 91, it is possible
to prevent the insulating tube 116 from coming off due to the
vibration of the compressor 4 and other disturbances, and stably
secure the insulation performance of the compressor 4.
[0063] On the other hand, in attaching the seal member 100 to the
rear casing 23, the bolt 102 is inserted into the through hole 104b
of the inner block 104 beforehand to become a unit, and this unit
is inserted in the insertion hole 23d of the rear casing 23. Then,
the through holes 114a and 106b of the insulating collar 114 which
is another unit, and the outer block 106 are sequentially aligned
with the bolt 102 projecting from the insertion hole 23d, and are
fitted thereover. Further, after the units are attached to the rear
casing 23, the nut 110 is screwed onto the bolt 102 from the
outside of the rear casing 23 to fasten them.
[0064] As apparent from the above, promotion of the unitization of
the parts at the time of attachment can reduce the number of the
seal members 100 and eventually the number of parts of the
compressor 4 even when there are a plurality of bolts 102 as in the
present embodiment, making it possible to prevent the lack of the
parts at the time of attachment.
[0065] Since attachment of the inner and outer blocks 104, 106, and
the insulating collar 114 to the rear casing 23 can be completed in
one attachment process each, it is possible to reduce the number of
attachment steps for the compressor 4 and further improve the
attachment. It is preferable that the input terminal member 108 and
the output terminal member 112 should be formed integral with the
bolt 102, making it possible to further reduce the number of the
parts of the compressor 4 and further improve the attachment.
[0066] On the other hand, the O ring 122 which seals the through
hole 104b and the inside of the rear casing 23 is disposed between
the through hole 104b of the inner block 104, and the intermediate
portion 102b of the bolt 102. Therefore, the refrigerant and oil
atmosphere in the rear casing are prevented from being leaked
outside the rear casing 23 through the through hole 104b and the
insertion hole 23d in the axial direction of the bolt 102, making
it possible to improve the sealing performance of the compressor
4.
[0067] The O ring 120 is disposed between the inner block 104 and
the inner end face 23b of the rear casing 23 to seal the insertion
hole 23d and the inside of the rear casing 23. Therefore, the
refrigerant and oil atmosphere in the rear casing 23 are prevented
from being leaked outside the rear casing 23 through the insertion
hole 23d in the radial direction of the bolt 102, making it
possible to further improve the sealing performance of the
compressor 4.
[0068] It is preferable that as shown in FIG. 3, the groove 104d
should be formed at the position where both the through hole 104b
of the inner block 104, and the insertion hole 23d can be sealed
simultaneously, and the O ring 118 is disposed there, making it
possible to enable sealing in both the axial direction and radial
direction of the bolt 102 with a single O ring. This can further
reduce the number of the parts of the compressor 4 and improve the
attachment nature thereof.
[0069] Further, the provision of such O rings 118, 120, 122 can
make the fastening force of the nut 110 to the bolt 102 relatively
smaller in addition to the improvement of the sealing performance,
making it possible to use bolts of inexpensive materials which
reduce the strength of the bolt 102. This brings about an effect of
reducing the manufacturing cost of the compressor 4.
[0070] Although the description of one embodiment of the present
invention is finished above, the invention is not limited to the
embodiment, and can be modified in various forms within the scope
of the invention.
[0071] For example, in the foregoing embodiment, besides the O ring
108, the two O rings 120, 122 may be attached as shown in FIG. 4,
but in case of attaching only one of the O rings 120, 122, the
sealing performance in at least one of the axial direction and
radial direction of the bolt 102 can be improved.
[0072] The O ring 120 may be provided so as to surround the three
bolts 104 for each inner block 104, not for each bolt 102, in which
case the number of the O rings 120 can be reduced and the
attachment of an O ring to the rear casing 23 can also be improved.
Further, the O ring 122 should abut on the intermediate portion
102b, and the same effect is acquired even if the O ring 122 is
provided to abut on the head section of the bolt 104 as illustrated
in the same diagram.
[0073] Furthermore, a gasket may be used in place of the O ring
118, 120, 122. In this case, since fastening force of the nut 110
to the bolt 102 can be made greater, making it possible to prevent
unnecessary rattling of the individual constituting parts, and
further improve the reliability of the compressor 4.
[0074] Moreover, although the insulating collar 114 is shown as one
member in the foregoing embodiment, it may be formed integral with
either one of the inner block 104 and the outer block 106, in which
case it is possible to further reduce the number of the parts of
the compressor 4 and further improve the attachment nature
thereof.
[0075] The inner and outer blocks 104, 106, and insulating collar
114 are made of a resin to contribute to the weight reduction of
the compressor 4 in the foregoing embodiment, but those materials
have only to have the insulating property, and may be, for example,
ceramics. In case where they are made of ceramics, it is hard to
cause time-dependent degradation as compared with the case where
they are made of a resin, making it possible to continuously keep
the fastening force of the bolt 102 and the nut 110 with respect to
the inner and outer blocks 104, 106, and continuously secure the
insulation performance of the insulating collar 114, so that the
reliability of the compressor 4 can be improved further.
[0076] Although the electric motor 40 of the embodiment is a
three-phase motor, it is not necessarily limited to this type, and
the embodiment can be adapted to, for example, a single-phase motor
or a two-phase motor, and the seal member and eventually the
compressor 4 can be made compact by providing the bolts 102 for the
number of the phases, and providing the through holes 104b, 106b
corresponding in number to the bolts 102 in the inner and outer
blocks 104, 106, respectively. Depending on the motor output, two
or more bolts 102 may be provided for each phase.
[0077] Finally, although the foregoing description of the
embodiment has been given of a scroll type motor-driven compressor,
the compressing unit of the invention can be adapted to either the
scroll type or piston reciprocation type, and the refrigerant used
in the refrigeration circuit may also be a chlorofluorocarbon
substitute as well as a CO.sub.2 refrigerant. In these cases, it is
possible to easily and surely improve the insulation performance
and the sealing performance of the compressor.
* * * * *