U.S. patent application number 11/627389 was filed with the patent office on 2007-10-04 for displacement type compressor.
Invention is credited to Makoto Aoki, Yuji Enomoto, Kazuyuki Fujimura, Satoshi Kikuchi, Mutsunori Matsunaga, Masashi Miyake, Tsutomu Nozaki, Takeshi Tsuchiya, Shinichi Wakui, Yuichi Yanagase.
Application Number | 20070231171 11/627389 |
Document ID | / |
Family ID | 38559206 |
Filed Date | 2007-10-04 |
United States Patent
Application |
20070231171 |
Kind Code |
A1 |
Tsuchiya; Takeshi ; et
al. |
October 4, 2007 |
DISPLACEMENT TYPE COMPRESSOR
Abstract
A displacement type compressor includes a compressing mechanism
section for performing a compression, a motor for driving the
compressing mechanism section, and a crankshaft adapted to be
driven in rotation by the motor to rotate the compressing mechanism
section. The motor includes stator cores and having claw-type
magnetic poles formed of a magnetic powder and circumferentially
arranged in alternately meshed states, and annular coils and wound
in a toric shape around the claw-type magnetic poles. Thus, the
displacement type compressor is capable of being at a high speed
and has a reduced size.
Inventors: |
Tsuchiya; Takeshi;
(Tsuchiura, JP) ; Yanagase; Yuichi; (Namegata,
JP) ; Fujimura; Kazuyuki; (Hitachinaka, JP) ;
Aoki; Makoto; (Kasama, JP) ; Miyake; Masashi;
(Shizuoka, JP) ; Matsunaga; Mutsunori; (Shizuoka,
JP) ; Enomoto; Yuji; (Hitachi, JP) ; Kikuchi;
Satoshi; (Hitachi, JP) ; Wakui; Shinichi;
(Hitachi, JP) ; Nozaki; Tsutomu; (Kashiwa,
JP) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET, SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
38559206 |
Appl. No.: |
11/627389 |
Filed: |
January 26, 2007 |
Current U.S.
Class: |
418/55.1 ;
418/55.5 |
Current CPC
Class: |
F04C 2240/40 20130101;
F04C 18/3564 20130101; F04C 18/0215 20130101; F04C 23/008 20130101;
F04C 29/0085 20130101 |
Class at
Publication: |
418/55.1 ;
418/55.5 |
International
Class: |
F01C 1/02 20060101
F01C001/02; F01C 1/063 20060101 F01C001/063 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 31, 2006 |
JP |
2006-096358 |
Claims
1. A displacement type compressor, comprising a compressing
mechanism section adapted to perform a compression, a motor for
driving said compressing mechanism section, and a crankshaft
adapted to be driven in rotation by said motor to rotate said
compressing mechanism section, wherein said motor comprises a
stator core in which claw-type magnetic poles formed of a magnetic
powder are circumferentially arranged in alternately meshed states,
and annular coils wound in a toric shape around said claw-type
magnetic poles.
2. A displacement type compressor according to claim 1, wherein
each of said claw-type magnetic poles has a resinous film formed
thereon.
3. A displacement type compressor according to claim 1, wherein
said compressing mechanism section comprises a fixed scroll and an
orbiting scroll meshed with each other to perform the compression
by the orbiting movement of said orbiting scroll.
4. A displacement type compressor according to claim 1, wherein
said stator core is fixed to a toric core frame which is disposed
within said displacement type compressor.
5. A displacement type compressor according to claim 1, wherein
said compressing mechanism section and said motor are disposed
between two shaft support portions on which said crankshaft is
rotatably supported.
6. A displacement type compressor according to claim 1, further
including a balance weight disposed between said compressing
mechanism section and said motor and having an outside diameter
smaller than an inside diameter of said stator core.
7. A displacement type compressor according to claim 1, further
including a balance weight disposed on the side of said compressing
mechanism section opposite from said motor.
8. A displacement type compressor according to claim 1, wherein
said compressing mechanism section comprises a fixed scroll and an
orbiting scroll meshed with each other to perform the compression
by the orbiting movement of said orbiting scroll, and said
crankshaft is passed through said orbiting scroll and said fixed
scroll and rotatably supported on portions of said orbiting scroll
and said fixed scroll through which said crankshaft is passed.
9. A displacement type compressor, comprising a compressing
mechanism section adapted to perform a compression, a motor for
driving said compressing mechanism section, a crankshaft adapted to
be driven in rotation by said motor to rotate said compressing
mechanism section, and two shaft support portions on which said
crankshaft is rotatably supported, wherein said motor comprises a
stator core in which claw-type magnetic poles formed of a magnetic
powder are circumferentially arranged in alternately meshed states,
and annular coils wound in a toric shape around said claw-type
magnetic poles, said compressing mechanism section comprises a
fixed scroll and an orbiting scroll meshed with each other to
perform the compression by the orbiting movement of said orbiting
scroll, said compressing mechanism section and said motor are
disposed between said shaft support portions, and a balance weight
is disposed between said compressing mechanism section and said
motor and has an outside diameter smaller than an inside diameter
of said stator core.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a displacement type
compressor for treating air, carbon dioxide and another
compressible gas, which may be used as an HFC refrigerant or a
natural refrigerant, and particularly, to a displacement type
compressor which is suitably designed to provide a high output,
while being small-sized.
[0003] 2. Description of the Related Art
[0004] A displacement type compressor representative of a scroll
compressor, a reciprocal compressor and a rotary compressor is
widely utilized in a variety of fields not only as a compressor for
a refrigerant air conditioner used for domestic, business,
in-vehicle applications or the like, but also as an air supply
compressor used for a source of air in a factory, for a fuel cell
or the like. A high-energy efficiency is required from the
viewpoint of prevention of global warming, and it is desired to
reduce the size of the compressor for promoting the reduction in
cost.
[0005] It is conventionally known that in order to reduce the size
of the compressor, the axial length of a motor for driving a
compressing mechanism section is reduced, or a claw-type pole motor
(a claw-type magnetic pole motor) having no coil end portion is
used to reduce the entire length of the compressor. This is
described, for example, in JP-A-2001-280247.
[0006] In the above-described conventional technique, the reduction
in size is provided merely by eliminating a coil end portion, and
hence, it is not sufficiently considered that the compressor is
operated at a high output and at a high speed in a range of larger
capacity. For this reason, claw-type magnetic poles must be axially
stacked as multiple layers for the purpose of an increase in
output, and the increase in output results in the impairment of
reduction in size for the original purpose.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to
provide a displacement type compressor which is capable of being
rotated at a high output and at a high speed and has a high-energy
efficiency and which is small-sized. It is another object of the
present invention to ensure that the axial length of, particularly,
a displacement type compressor is reduced, and the reliability is
enhanced.
[0008] To achieve the above object, according to the present
invention, there is provided a displacement type compressor,
comprising a compressing mechanism section adapted to perform a
compression, and a motor for driving the compressing mechanism
section, wherein the motor comprises a stator core in which
claw-type magnetic poles formed of a magnetic powder are
circumferentially arranged in alternately meshed states, and
annular coils wound in a toric shape around the claw-type magnetic
poles.
[0009] With the arrangement of the above feature, the motor is
constructed using the claw-type magnetic poles formed of the
magnetic powder. Therefore, it is possible to provide a
displacement type compressor which is capable of being rotated at a
higher speed and which has a high-energy efficiency.
[0010] The above and other objects, features and advantages of the
invention will become apparent from the following description of
the preferred embodiment taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a sectional view showing the entire compressor
according to one embodiment of the present invention;
[0012] FIG. 2 is a sectional view showing a stator core in the
embodiment;
[0013] FIG. 3 is a plan view showing a claw-type core portion in
the embodiment;
[0014] FIG. 4 is a sectional view showing the claw-type core
portion in the embodiment;
[0015] FIG. 5A is a plan view of a rotor in the embodiment;
[0016] FIG. 5B is a plan view of other rotor in the embodiment;
[0017] FIG. 5C is a plan view of other rotor in the embodiment;
[0018] FIG. 6 is a sectional view showing the entire compressor
according to another embodiment of the present invention;
[0019] FIG. 7 is a sectional view showing the entire compressor
according to a further embodiment of the present invention;
[0020] FIG. 8 is a view showing the entire compressor according to
a yet further embodiment of the present invention; and
[0021] FIG. 9 is a sectional view showing the entire compressor
according to a yet further embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0022] A displacement type compressor according to an embodiment of
the present invention will now be described with reference to FIGS.
1 to 5.
[0023] The displacement type compressor includes a compressing
mechanism section 1 using a scroll compressing mechanism which is
small-sized and capable of providing a high output, and a drive
means contained in a closed container 5 for driving an orbiting
scroll 3 in orbiting movement. The compressing mechanism section 1
comprises a fixed scroll 2, the orbiting scroll 3 and a frame 4 as
basic elements. The fixed scroll 2 or the frame 4 is fixed to the
closed container 5.
[0024] The fixed scroll 2 includes a spiral wrap 2a, a mirror plate
2b and a discharge bore 2c, and is fixed to the frame 4 through a
bolt. The wrap 2a is mounted on the mirror plate 2b to rise
vertically. The orbiting scroll 3 has a spiral wrap 3a, a mirror
plate 3b and a shaft support portion 3c. The wrap 3a is mounted on
the mirror plate 3b to rise vertically. A compression chamber 7, in
which the fixed scroll 2 and the orbiting scroll 3 are meshed with
each other, performs a compressing motion, whereby the volume of
the compression chamber 7 is decreased by the orbiting movement of
the orbiting scroll 3.
[0025] With the orbiting movement of the orbiting scroll 3, a
working fluid is drawn via an intake space 9 into the compression
chamber 7, and the drawn working fluid is discharged through the
discharge bore 2c into a discharge space 10 via a compression
stroke and further discharged from the closed container 5 via a
discharge port 11. This causes a space within the closed container
5 to be maintained at a discharge pressure. An over-compression
preventing means (not shown) is also mounted in order to prevent an
over-compression caused during an operation with a pressure ratio
lower than a design pressure ratio. The over-compression preventing
means includes a passage permitting the communication between the
compression chamber 7 and the discharge space 10, and a valve
adapted to open the passage when an over-compression is
reached.
[0026] The drive means for driving the orbiting scroll 3 in
orbiting movement includes a motor 23 comprising a stator 21 using
stator cores 21a, 21b and 21c with claw-type core portions formed
of a magnetic powder and meshed with each other, and a rotor 22, a
crankshaft 24, an Oldham's ring 25 which is a main component for an
automatic preventing mechanism for the orbiting scroll 3, the frame
4 and a sub frame 12.
[0027] The motor 23 provides a rotating action to the crankshaft
24. The crankshaft 24 includes a main shaft portion 24a, a sub
shaft portion 24b and an eccentric pin portion 24c. A shaft support
portion 6 disposed on the frame 4 and a shaft support portion 26
disposed on the sub frame 12 provide shaft supports with which the
main shaft portion 24a and the sub shaft portion 24b of the
crankshaft 24 are rotatably engaged, and the eccentric pin portion
24c of the crankshaft 24 is engaged for movement in a rotationally
axial direction and for rotation with the orbiting shaft support
portion 3c disposed on the orbiting scroll 3. The shaft support
portions 6 and 26 for the crankshaft are disposed on the side of
the compressing mechanism section 1 opposite from the motor and on
the side of the motor opposite from the compressing mechanism
section, respectively. It should be noted that in addition to a
sliding bearing, a rolling bearing adaptable for service conditions
and another shaft support member may be used for each of the shaft
support portions 3c, 6 and 26.
[0028] The Oldham's ring 25 is disposed in a space defined by the
orbiting scroll 3 and the frame 4. One of two sets of perpendicular
key portions formed on the Oldham's ring 25 slides in a key groove
27a which is a receiver for the Oldham's ring 25 and formed in the
frame 4, and the remaining one set slides in a key groove 27b
formed in a back of the orbiting scroll wrap 2a. Thus, the orbiting
scroll 3 is orbited, without being rotated about its own axis, in a
plane perpendicular to an axial direction which is a direction of
rising of the scroll wrap.
[0029] To fix the stator 21 within the closed container 5, the
stator cores 21a, 21b and 21c are accommodated into a core frame
30, and the core frame 30 is engaged with the fixed scroll 2. If a
mating member with which the core frame 30 is engaged is the fixed
scroll 2, the engagement can be achieved at a high accuracy, but
the core frame 30 may be engaged with a portion of the compressing
mechanism section 1, or the closed container 5.
[0030] FIG. 2 shows one of the stator cores 21a, 21b and 21c in an
enlarged scale, wherein the stator core includes a first claw-type
core portion 31 and a second claw-type core portion 32. Annular
coils 21d, 21e and 21f are provided within the stator core.
[0031] A claw-type magnetic pole 33 is provided in an axially
folded state on the claw-type core portion in the form of a
magnetic pole surface opposed to the rotor 22. The annular coils
21d, 21e and 21f are wound in a toric shape around the claw-type
magnetic poles 33. In the stator core, two claw-type core portions
are arranged circumferentially in a state in which the claw-type
magnetic poles provided on the claw-type core portions are
alternately meshed together.
[0032] Further, FIG. 3 is a view showing the arrangement of the
second claw-type core portion 32, and FIG. 4 shows a section of the
second claw-type core portion 32 taken along a line A-A in FIG. 3.
In FIGS. 2 to 4, two claw-type magnetic poles are present per one
claw-type core portion and hence, four claw-type magnetic poles are
present on one stator core. Thus, the motor 23 acts as a
four-magnetic pole motor.
[0033] As shown in FIG. 1, in the three stator cores 21a, 21b and
21c has the claw-type poles displaced circumferentially by
120.degree. in each of them, and are driven by a three-phase AC
power source. Each of the stator cores 21a, 21b and 21c has the
claw-type core portions formed of the magnetic powder and hence, if
the distance between the outer periphery of the rotor 22 and the
claw-type magnetic pole is reduced, it is feared that the magnetic
powder is dropped from each of the claw-type core portions,
resulting in a detracted reliability. In order to prevent this, a
resinous film is formed on each of the claw-type core portions. A
material which may be used for the resinous film includes PPS
(polyphenylene sulfide)-based resin which is a thermo plastic
engineering plastic having a good heat resistance, and the
like.
[0034] The rotor 22 is preferred to be one having a magnet disposed
on its surface, because of its low price, but may be any other
rotor such as a cage-shaped rotor as shown in FIG. 5A, a rotor as
shown in FIG. 5B and having a cage-shaped conductor and a magnet
and a rotor as shown in FIG. 5C and having a flux barrier (slit),
if a magnetic pole engaged with a claw-type magnetic pole can be
formed on the rotor. In FIG. 5, each of 40 and 41 designates the
case-shaped conductor; 42 designates the magnet; and 43 designates
the flux barrier.
[0035] The sub frame 12 having the shaft support portion 26
disposed thereon is engaged with the core frame 30. It should be
noted that a mating member with which the sub frame 12 is engaged
may be the closed container 5. The sub frame 12 is provided with a
thrust bearing 13 adapted to receive a load when the crankshaft 24
is moved downwards. When the crankshaft 24 is moved upwards, the
load is received by a thrust receiver 18.
[0036] To lubricate the shaft support portions 3c, 6 and 26, an oil
supply pump 14 is mounted at a lower portion of the sub frame 12
and rotated by the rotation of the crankshaft 24 to realize the
pumping action. More specifically, a lubricating oil accumulated in
a lower space in the closed container 5 is sucked by the oil supply
pump 14 and supplied to the various portions through an oil supply
passage 24d provided in the crankshaft or the like. The oil supply
pump 14 may be a centrifugal pump (not shown) formed on the
crankshaft to realize an eccentric rotational motion. The
lubricating oil supplied to the shaft support portions 3c and 6 can
be supplied only in an amount required for lubricating the inside
of the compression chamber 7 through a circular seal member 18
disposed on the frame 4 and a small oil supply bore 20.
[0037] In order to eliminate an eccentric unbalance caused by the
rotation of the orbiting scroll 3, the eccentric pin portion 24c of
the crankshaft or the like, balance weights 15 and 16 are disposed
on the side of the compressing mechanism section 1 opposite from
the motor and between the compressing mechanism section 1 and the
motor 23, respectively. The balance weight 16 between the
compressing mechanism section 1 and the motor 23 is of a shape
smaller than inside diameters of the stator 21 and the stator cores
21a, 21b and 21c and hence, is capable of being passed through an
inside diameter portion of the stator 21 through the crankshaft
24.
[0038] According to the above-described arrangement, the motor 23
using the stator cores with the claw-type core portions formed of
the magnetic powder being meshed with one another can be reduced in
axial length because of having no end coil, as is a conventional
claw-type magnetic pole motor; and this motor is capable of being
rotated at a high speed and has a high-energy efficiency
characteristic and a high-output characteristic. Therefore, the
axial length of the crankshaft 24 can be also reduced by the
reduction in size of the motor 23, and hence, the deformation of
the crankshaft 24 can be reduced to suppress the one-sided striking
on the shaft support portion, leading to an increase in reliability
of the shaft support portion.
[0039] In addition, it is possible to provide a reduction in size
and an increase in speed of the displacement type compressor, and
because the resinous film is applied to each of the claw-type core
portions 31 and 32 to prevent the dropping of the powder from the
claw-type core portions 31 and 32, it is possible to prevent the
biting-in of foreign matters in the compressor, leading to an
increase in reliability.
[0040] Further, because the claw-type core portions 31 and 32
formed of the magnetic powder are contained in the core frame 30,
it is possible to prevent the fracture of the claw-type core
portions due to the fitting of the stator core into the closed
container, and to eliminate the deformation of the closed container
due to the fitting. This means that the components to be engaged
with the closed contained can be assembled with a good
accuracy.
[0041] Furthermore, it is possible to position the shaft support
portion 6 provided on the frame 4 and the stator core 21 at a
coaxiality of a high accuracy.
[0042] Yet further, the core frame 30 can be fixed in an engaged
manner to the sub frame 12 provided with the shaft support portion
26 and hence, it is possible to position the shaft support portion
6 provided on the frame 4, the stator 21 and the shaft support
potion of the sub frame 12 at a coaxiality of a high accuracy.
[0043] Moreover, because the axial length of the displacement type
compressor can be reduced, the axial length of the crankshaft 24
can be further reduced; the compressing mechanism section 1 and the
motor 23 can be disposed between the two shaft support portions 6
and 26 with which the crankshaft 24 is rotatably engaged, and the
balance weights for eliminating the eccentric unbalance can be
disposed on the side of the compressing mechanism section 1
opposite from the motor and between the compressing mechanism
section 1 and the motor 23, respectively, thereby further reducing
the deformation of the crankshaft 24 during operation at a high
speed. Thus, it is possible to provide an increase in reliability
during operation at the high speed and to reduce a loss of sliding
of the bearing due to the deformation of the crankshaft.
[0044] Further, the outside diameter of the balance weight disposed
between the compressing mechanism section 1 and the motor 23 is
smaller than the inside diameters of the stator 21 and the stator
cores 21a, 21b and 21c and hence, it is possible to enhance the
assemblability and to provide a reduction in size and an increase
in speed by use of the scroll compressing mechanism section as the
compressing mechanism section 1. The arrangement is such that the
crankshaft 24 is mounted to extend through the orbiting scroll 3
and the fixed scroll 2, and the compressing mechanism section is
sandwiched between the shaft support portions 6 and 26. Therefore,
it is possible to rationalize the offset of the load on the shaft
support portions and to reduce the deformation of the crankshaft
caused by the remarkable eccentric unbalance during operation at
the high speed.
[0045] A displacement type compressor according to a second
embodiment of the present invention will now be described in detail
with reference to FIG. 6. FIG. 6 shows the entire structure of a
scroll compressor in the second embodiment. The arrangement of
shaft support portions 6 and 50 for a crankshaft, a thrust bearing
13, a thrust bearing support portion 51 and an oil supply way are
different from those in the first embodiment.
[0046] For the shaft support portions for the crankshaft 24, a
shaft support portion 50 is formed on a fixed scroll 2. A sub shaft
portion 24e of the crankshaft is rotatably engaged with the shaft
support portion 50, and the deformation of the crankshaft 24 due to
the whirling of the rotor 22 is influenced at most to a small
extent.
[0047] The thrust bearing 13 and a thrust bearing 18 for supporting
an axial force of the crankshaft 24 are provided on the thrust
bearing support portion 51 and the frame 4, but if thrust bearings
are provided at opposite ends of the eccentric pin portion 24c of
the crankshaft, the structure is more simplified. In FIG. 6, the
thrust bearing support portion 51 is engaged with the core frame 30
by a bolt.
[0048] The oil supply way is a centrifugal oil supply way which is
effected by the rotation of the eccentric oil supply passage 24f
within the crankshaft 24. Therefore, it is possible to reduce the
number of parts, despite the disposition of the shaft support
portion 50.
[0049] By virtue of the disposition of the shaft support portion 50
for supporting the sub shaft portion 24c of the crankshaft 24 on
the fixed scroll 2, as described above, it is possible to reduce
the number of parts in the entire compressor and to construct the
compressor having a simple arrangement, a small size and a high
efficiency.
[0050] A displacement type compressor according to a third
embodiment of the present invention will now be described with
reference to FIG. 7. FIG. 7 shows the entire structure of a rotary
compressor.
[0051] A drive source is a motor 23 which is comprised of a stator
21 comprising stator cores 21am 21b and 21c each constituted of
claw-type core portions formed of a magnetic powder and meshed with
each other and annular coils 21d, 21e and 21f, and a rotor 22. The
stator cores 21a 21b and 21c are contained in a core frame 30.
[0052] A compressing mechanism section 101 of the rotary compressor
is comprised of a cylinder 102, a first end plate 103 and a second
end plate 104 for closing opposite ends of the cylinder 102, a
roller 105 disposed in a space surrounded by the cylinder 102, the
first end plate 103 and the second end plate 104, and a vane (not
shown) having a function of changing the volume of a space defined
by the cylinder 102, the first end plate 103, the second end plate
104 and the roller 105 in accordance with the movement of the
roller 105. A compressing chamber 106 is a space volume which is
defined by the cylinder 102, the first end plate 103, the second
end plate 104, the roller 105 and the vane, and which is varied in
accordance with the movement of the roller 105. A working fluid is
drawn via an intake port 107 into the compressing chamber 106. The
working fluid is compressed with the movement of the roller 105 and
discharged into a discharge space 110 within a closed container 112
via a discharge bore 108 provided in the second end plate 104 and a
discharge valve 109 and further discharged from the closed
container 112 via a discharge port 111.
[0053] A means for driving the roller 105 includes a motor 23, a
crankshaft 120, a first end plate 103 and a sub frame 121. The
crankshaft 120 includes a main shaft portion 120a, a sun shaft
portion 120b and an eccentric pin portion 120c. A shaft support
portion 122 disposed on the first end plate 103 and a shaft support
portion 123 disposed on the sub frame 121 provide shaft support
portions with which the main shaft portion 120a and the sub shaft
portion 120b of the crankshaft 120 are rotatably engaged, and the
roller 105 is rotatably engaged with the eccentric pin portion 120c
of the crankshaft 120. The shaft support portions 122 and 123 for
the crankshaft are disposed on the side of the compressing
mechanism section 101 opposite from the motor and on the side of
the motor 23 opposite from the compressing mechanism section,
respectively. In addition to a sliding bearing which may be used
for each of the shaft support portions 122 and 123, a rolling
bearing is suitable for the rotation at a high speed and at a high
load.
[0054] A thrust bearing 130 is disposed on the sub frame 121 and
adapted to receive a load when the crankshaft 120 is moved
downwards. When the crankshaft 120 is moved upwards, a thrust
bearing 131 supports the load.
[0055] To lubricate slide contact surfaces of the shaft support
portions 122 and 123, the roller 105 and the eccentric pin portion
120c of the crankshaft, a pumping action is realized by employing
both of a centrifugal oil supply action caused by the rotation of
an eccentric oil supply passage 120d within the crankshaft 120 and
a differential oil supply action caused by a difference in pressure
between the compressing chamber 106 and a discharge space 110
within a closed container 112. More specifically, a lubricating oil
132 accumulated in a lower space in the closed container 112 is
sucked by the oil supply pumping action and supplied to various
portions through the oil supply passage 120d provided in the
crankshaft. An oil supply pump which may be used includes a
trochoid pump or the like as an external oil supply pump which is
not shown.
[0056] In order to eliminate an eccentric unbalance caused by the
rotation of the roller 105, the eccentric pi portion 120c of the
crankshaft or the like, balance weights 133 and 134 are disposed on
the side of the compressing mechanism section 101 opposite from the
motor and between the compressing mechanism section 1 and the motor
23, respectively. The balance weight 134 between the compressing
mechanism section 101 and the motor 23 is of a shape smaller than
an inside diameter of the stator 21 and hence, is capable of being
passed through an inside diameter portion of the stator 21 through
the crankshaft 120.
[0057] With the above-described arrangement, the axial length of
the motor is short, and the axial length of the displacement type
compressor can be further reduced using a core frame structure.
Therefore, the axial length of the crankshaft 120 can be further
reduced; the compressing mechanism section 101 and the motor 23 can
be disposed between the two shaft support portions 122 and 123 with
which the crankshaft 24 is rotatably engaged, and the balance
weights for eliminating the eccentric unbalance can be disposed on
the side of the compressing mechanism section 101 opposite from the
motor and between the compressing mechanism section 101 and the
motor 23, respectively, thereby further reducing the deformation of
the crankshaft 120 during operation at a high speed. Thus, it is
possible to provide an increase in reliability during operation at
the high speed and to reduce a loss of sliding of the bearing due
to the deformation of the crankshaft, leading to an increase in
energy efficiency.
[0058] In addition, the outside diameter of the balance weight 134
disposed between the compressing mechanism section 101 and the
motor 23 can be set to be smaller than the inside diameter of the
stator 21, leading to an enhanced assemblability. Therefore, it is
possible to rationalize the load on the shaft support portions and
to further reduce the deformation of the crankshaft caused by the
remarkable eccentric unbalance during operation at the high speed,
thereby realizing the rotary compressor capable of being operated
at the high speed and having a high-energy efficiency.
[0059] A displacement type compressor according to a fourth
embodiment of the present invention will now be described in detail
with reference to FIG. 8. FIG. 8 shows the entire structure of a
rotary compressor.
[0060] For a shaft support portion for a crankshaft 120, a shaft
support portion 140 is provided on a second end plate 104. A thrust
bearing 141 and a thrust bearing 131 for supporting an axial force
of the crankshaft 120 are formed on the side of the eccentric pin
portion 120c of the crankshaft 120 closer to the motor and at the
first end plate 103, respectively, but both of the thrust bearings
may be formed at opposite ends of the eccentric pin portion 120c of
the crankshaft, and in the latter case, it is possible to provide a
further simplification.
[0061] A displacement type compressor according to a fifth
embodiment of the present invention will now be described in detail
with reference to FIG. 9. FIG. 9 shows the entire structure of a
rotary compressor.
[0062] This displacement type compressor has a feature in that a
compressing mechanism section 154 is disposed in a lower portion of
a closed container 112 and balance weights 150 and 151 are disposed
at opposite ends of a rotor 22. The balance weights 150 and 151
need not be engaged directly with the rotor 22, and may be disposed
on a crankshaft. A thrust bearing 153 and a thrust bearing 152 for
supporting an axial force of the crankshaft 120 are formed at
opposite ends of an eccentric pin portion 120c of the crankshaft
120 for the purpose of the simplification. In place of the
provision of the thrust bearing 153, a thrust load can be received
on a first end plate itself, and in this case, it is possible to
provide a further simplified structure.
[0063] As described above, a resinous film can be applied to each
of claw-type core portions formed of a magnetic powder formed with
an insulating film, thereby preventing the dropping of the powder
from the claw-type core portions formed of the magnetic powder and
constituting a stator core of a motor, thus ensuring the
reliability of the displacement type compressor.
[0064] In addition, it is not required that the stator core
comprised of the claw-type core portions formed of the magnetic
powder is fit directly to a compressor casing and hence, it is
possible to eliminate a fitting force applied to the claw-type core
portions formed of the magnetic powder and to prevent the fracture
of the claw-type core portions formed of the magnetic powder.
Further, it is possible to reduce the deformation of the compressor
casing due to the fitting and hence, it is possible to assemble
parts to be engaged with the compressor casing at a good
accuracy.
[0065] Further, the motor can be disposed in further proximity to
the compressing mechanism section and hence, it is possible to
provide a reduction in axial length of the displacement type
compressor; to ensure the coaxiality at a high accuracy between the
crank shaft support portion provided on the side of the compressing
mechanism section opposite from the motor and the stator core; and
to reduce the flexure of the crankshaft to reduce the deformation
of the crankshaft due to an eccentric unbalance during rotation at
a high speed, leading to an increase in reliability.
[0066] Furthermore, it is possible to maintain the coaxiality at a
high accuracy between the crankshaft support portion provided on
the compressing mechanism section, the stator core and the
crankshaft support portion provided on the motor. Therefore, the
balance weights can be passed through the inside of the stator,
leading to an enhancement in assemblability of the compressor.
[0067] Yet further, the disposition of the crankshaft support
portions on the opposite sides of the compressing mechanism section
ensures that an increase in a bearing load due to the reduction in
length of the crankshaft is not brought out, and besides, the
eccentric unbalance during operation at the high speed can be
reduced.
[0068] It should be further understood by those skilled in the art
that although the foregoing description has been made on
embodiments of the invention, the invention is not limited thereto
and various changes and modifications may be made without departing
from the spirit of the invention and the scope of the appended
claims.
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