Note: Descriptions are shown in the official language in which they were submitted.
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HYBRID COMPRESSOR
Technical Field of the Invention
[0001] The present invention relates to a hybrid compressor in which a first
compression
mechanism driven by an external drive source and a second compression
mechanism driven
by a built-in electric motor are assembled integrally and which is used in air
conditioning
systems for vehicles, etc., and specifically, to a hybrid compressor the motor
section of which
can be cooled more effectively.
Background Art of the Invention
[0002] Various proposals have been carried out for this type of hybrid
compressors (for
example, Patent document 1). A conventional hybrid compressor has a structure,
for
example, as shown in Fig. 1. Hybrid compressor 1 depicted in Fig. 1 is a
scroll type
compressor, and has a first compression mechanism 2 and a second compression
mechanism
3. First compression mechanism 2 has a fixed scroll 10, a movable scroll 11
forming a
plurality of pairs of operational spaces (fluid pockets) 12 by engaging with
fixed scroll 10, a
drive shaft 13 driving movable scroll 11 at an orbital movement by engaging
with movable
scroll 11, an electromagnetic clutch 15 for an on-off operation of the
transmission of a driving
force between a pulley 14, to which the driving force from a drive source for
running a vehicle
(not shown) provided as an external drive source is transmitted via a belt,
and the drive shaft
13, a ball coupling 16 for preventing the rotation of movable scroll 11, and a
suction port 18
formed on a casing 17. The gas to be compressed (for example, refrigerant)
sucked from
suction port 18 into a suction chamber 20 through a suction path 19 is taken
into operational
spaces 12, the operational spaces 12 are moved toward the center of fixed
scroll 10 while the
volumes of the operational spaces 12 are decreased, and by this operation, the
refrigerant gas
in the operational spaces 12 is compressed. A discharge hole 21 is formed on
the central
portion of fixed scroll 10, and the compressed refrigerant gas is discharged
to a high-pressure
side of an external refrigerant circuit through the discharge hole 21, a
discharge path 22 and a
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discharge port 23.
[0003] On the other hand, second compression mechanism 3 has a fixed scroll
30, a movable
scroll 31 forming a plurality of pairs of operational spaces (fluid pockets)
32 by engaging with
fixed scroll 30, a drive shaft 33 driving movable scroll 31 at an orbital
movement by engaging
with movable scroll 31, and a ball coupling 34 for preventing the rotation of
movable scroll
31. An electric motor 35 is incorporated in order to drive the drive shaft 33
of this second
compression mechanism 3. Electric motor 35 has a rotor 36 fixed to drive shaft
33 and a
stator 37 having a motor coil part, the stator 37 is fixed to a stator housing
38 or a stator
housing 38 which is formed as a part of the compressor housing, and the whole
of electric
motor 35 is contained in the stator housing 38. An electricity is supplied to
electric motor 35
via a power supply portion 50. In this second compression mechanism 3, the gas
to be
compressed (for example, refrigerant) sucked from suction port 18 into suction
chamber 20 of
first compression mechanism 2 is sucked into a suction chamber 40 of second
compression
mechanism 3 and a portion of electric motor 35 (an electric motor side suction
chamber)
through a communication path 39. The gas sucked into suction chamber 40 of
second
compression mechanism 3 is taken into operational spaces 32, the operational
spaces 32 are
moved toward the center of fixed scroll 30 while the volumes of the
operational spaces 32 are
decreased, and by this operation, the refrigerant gas in the operational
spaces 32 is
compressed. A discharge hole 41 is formed on the central portion of fixed
scroll 30, and the
compressed refrigerant gas is discharged to the high-pressure side of the
external refrigerant
circuit through the discharge hole 41 and a discharge path 42.
[0004] Fixed scroll 10 of first compression mechanism 2 and fixed scroll 30 of
second
compression mechanism 3 are disposed back to back, and both fixed scrolls 10
and 30 are
formed as an integrated fixed scroll member 43. In this example, communication
path 39 is
formed in this fixed scroll member 43.
[0005] In the hybrid compressor 1, when first compression mechanism 2 is only
operated, an
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electricity is not supplied to electric motor 35 for driving second
compression mechanism 3,
and the electric motor 35 is not rotated. Therefore, second compression
mechanism 3 does
not operate. When the hybrid compressor 1 is driven only by electric motor 35,
the electric
motor 35 is turned to be on and rotated, the rotation of the electric motor 35
is transmitted to
drive shaft 33 of second compression mechanism 3, and the orbital movement of
movable
scroll 31 is performed by the drive shaft 33. At that time, electromagnetic
clutch 15 of first
compression mechanism 2 is not excited, and the rotation of the drive source
for running a
vehicle as a first drive source is not transmitted to the first compression
mechanism 2.
Therefore, first compression mechanism 2 does not operate. When both first and
second
compression mechanisms 2 and 3 are driven simultaneously, the driving force
from the drive
source for running a vehicle is transmitted to movable scroll 11 of first
compression
mechanism 2 as well as electric motor 35 is turned to be on and the driving
force thereof is
transmitted to movable scroll 31 of second compression mechanism 3.
[0006] In the hybrid compressor 1 thus constructed, the control for switching
between first
compression mechanism 2 and second compression mechanism 3 and for
simultaneous
operation is performed in accordance with the load condition for cooling, etc.
For example,
in a light load condition where a great cooling ability is not required in a
vehicle interior, a
sole operation mode of the motor side having a small displacement (that is,
second
compression mechanism 3 side), or a simultaneous operation mode, in which the
external
drive source side having a great displacement relative to the motor side (that
is, first
compression mechanism 2 side) is rotated at a low rotational speed and the
motor is also
operated, is employed. The motor is operated through the control of the
rotational speed, for
example, by duty controlling the pulse voltage applied to the motor from a
high voltage part in
accordance with the demand from an exclusive drive control circuit. The motor
coil part has
a resistance, an electric current flows through the resistance, and the motor
coil part is heated.
The motor coil part is cooled by the passage of the refrigerant or by the
thermal transmission
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from the motor coil part to the stator housing side and the heat radiation
from the stator
housing to the atmosphere, etc. The temperature of the motor coil part is
decided depending
upon the balance between the amount of the above-described heating and the
amount of the
above-described heat radiation. In the operational mode of sole drive of the
motor side
(second compression mechanism 3 side) or the simultaneous operational mode
where first
compression mechanism 2 is driven at a low rotational speed and second
compression
mechanism 3 is also driven, when the amount of the above-described heating of
the motor coil
part exceeds the amount of the above-described heat radiation (for example,
when the vehicle
condition is turned from a highway running in a summer time to a vehicle
stopping and idling
in a parking zone), the temperature of the motor coil part may exceed an
acceptable
temperature, and at worst, the initiation of the motor may be damaged.
Therefore, it is
necessary to properly cool the motor portion including the motor coil part so
that the
temperature thereof does not exceed the acceptable temperature.
[0007] From the viewpoint described above, in particular, from the viewpoint
of
improvement of the cooling ability of the motor portion, a structure is known
wherein the
refrigerant sucked through the communication path is sucked into the suction
chamber of the
electric motor side, and therefrom, sucked into suction chamber 40 of second
compression
mechanism 3. For example, as depicted in Fig. 2, a structure is employed
wherein the
refrigerant sucked into suction chamber 20 of first compression mechanism 2
via suction path
19 is sucked into electric motor side suction chamber 51 through a
communication path 52
extended up to the electric motor side suction chamber 51 (a communication
path
corresponding to communication path 39 depicted in Fig. 1), the refrigerant is
used for
cooling the motor by being passed through the vicinity of motor 35, and
therefrom, the
refrigerant is sucked into suction chamber 40 of second compression mechanism
3 via suction
passageway 53.
[0008] In the motor cooling structure using the refrigerant as shown in Fig.
2, the respective
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members have been structured, for example, as shown in Figs. 3 to 6. Figs. 3
and 4 depict an
example of a center plate 54 provided between electric motor side suction
chamber 51 and
second compression mechanism 3, and to this center plate 54, communication
paths 52 having
communication openings 55 as openings at electric motor side suction chamber
51, and
suction passageways 53 having suction openings 56 as openings at electric
motor side suction
chamber 51, are provided. As shown in Fig. 4, communication openings 55 and
suction
openings 56 are almost over the entire circumference.
[0009] Further, Figs. 5 and 6 depict an example of a fixed scroll member 57
which is formed
by forming a fixed scroll of first compression mechanism 2 and a fixed scroll
of second
compression mechanism 3 integrally in a form of back to back, and in this
fixed scroll member
57, communication paths 52 are provided in the circumferential direction as
shown in Fig. 6.
Where, symbols 58 represent bolt holes which are provided at four positions in
the
circumferential direction.
[0010] However, in the conventional hybrid compressor having the structure as
depicted in
Figs. 3 to 6, as shown by arrows in Fig. 2, the refrigerant gas sucked into
electric motor side
suction chamber 51 from suction chamber 20 side of first compression mechanism
2 through
communication path 52 and communication opening 55 is likely to be sucked to
suction
opening 56 which is located at a closest position relative to the
communication opening 55,
and therefrom, the refrigerant gas is sucked into suction chamber 40 of second
compression
mechanism 3 via suction passageway 53. Therefore, in a place apart from these
communication opening 55 and suction opening 56, there is a fear that the
refrigerant gas
stays in electric motor side suction chamber 5 1. As a result, a motor
portion, which is
positioned apart from these communication opening 55 and suction opening 56,
may not be
cooled sufficiently by the sucked gas, and it may be overheated.
Patent document 1: JP-A-2004-278339
Disclosure of the Invention
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Problems to be solved by the Invention
[0011] Accordingly, an object of the present invention is to provide a
structure of a hybrid
compressor which can appropriately cool a section of a built-in electric motor
over a wider
area by sucked gas, thereby suppressing a rise in temperature of the motor
section more
properly, and further thereby making it possible to enlarge an available motor
operational
range.
Means for solving the Problems
[0012] To achieve the above-described object, the present invention provides a
hybrid
compressor has a first compression mechanism driven only by an external drive
source, a
second compression mechanism driven only by a built-in electric motor, a
suction path for
sucking gas to be compressed into the first compression mechanism, a
communication path
for sucking the gas from the first compression mechanism side into an electric
motor side
suction chamber, and a suction passageway for sucking the gas from the
electric motor side
suction chamber to the second compression mechanism side, and the hybrid
compressor is
characterized in that positions and/or number of the communication path and/or
the suction
passageway, and/or positions and/or number of a communication opening, which
is an
opening of the communication path that is opened at the electric motor side
suction chamber,
and/or a suction opening, which is an opening of the suction passageway that
is opened at the
electric motor side suction chamber and located on a side opposite to the side
of the
communication opening, are limited so that, with respect to at least a part of
the gas sucked
into the electric motor side suction chamber via the communication path, a gas
flow is formed
from the communication opening to the suction opening.
[0013] In this hybrid compressor, a structure may be employed wherein the
communication
opening is provided only at a position on one side in the electric motor side
suction chamber,
and the suction opening is provided only at a position on a side opposite to
the above-
described one side in the electric motor side suction chamber.
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[0014] Further, a structure may be employed wherein the communication opening,
the
communication path, the suction passageway and the suction opening are
provided at plurality
conditions, respectively.
[0015] Further, a structure may be employed wherein a center plate is provided
between the
electric motor side suction chamber and the second compression mechanism, and
the
communication opening and the suction opening are formed on the center plate.
[0016] Furthermore, a structure may be employed wherein a fixed scroll of the
first
compression mechanism and a fixed scroll of the second compression mechanism
are
integrally formed as a common fixed scroll member, and a part of the
communication path is
formed on the fixed scroll member.
[0017] Where, as the external drive source, a drive source for running a
vehicle (including
both an engine such as an internal combustion engine and an electric motor for
running a
vehicle in a case of an electric car, etc.) can be employed. Further, as the
gas to be
compressed, refrigerant can be employed.
[0018] In such a hybrid compressor according to the present invention, when a
rise in
temperature occurs in the built-in electric motor, particularly in its coil
portion, by the heating
accompanying with increase of electric current, an excessive rise in
temperature of the motor
section may be appropriately suppressed as follows. Namely, in the
aforementioned
conventional structure, because the sucked gas is likely to flow from the
communication
opening at the electric motor side suction chamber to the suction opening
located at the closest
position, the sucked gas is liable to stay in a motor portion apart from both
openings and the
motor portion becomes hard to be cooled, and therefore, the motor section may
be overheated.
In the present invention, however, by disposing the communication path,
particularly, the
communication opening, and the suction passageway, particularly, the suction
opening, at
positions opposite to each other, the sucked gas flowing from the
communication opening to
the suction opening flows over a wide area without staying, the motor is
properly cooled over
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a wide area, and occurrence of an overheating may be prevented. Further, as
the result that
the motor is appropriately cooled over a wide area, the available operational
range of the
motor can be enlarged.
Effect according to the Invention
[0019] Thus, in the hybrid compressor according to the present invention, the
sucked gas for
cooling can be flowed over a wide area in the electric motor side suction
chamber without
being stayed, the whole of the motor can be appropriately cooled, and a rise
in temperature of
the motor at the time of motor operation can be suppressed low. Therefore,
occurrence of an
inconvenience accompanying with an overheating of the motor can be avoided,
and the
available operational range of the motor can be enlarged.
Brief explanation of the drawiM
[0020]
[Fig. 1] Fig. I is a vertical sectional view of a conventional hybrid
compressor.
[Fig. 2] Fig. 2 is a schematic vertical sectional view showing an example of a
structure for
cooling a motor section in the conventional hybrid compressor.
[Fig. 3] Fig. 3 is a schematic vertical sectional view showing an example of a
center plate
in the structure depicted in Fig. 2.
[Fig. 4] Fig. 4 is an elevational view showing an example of the disposition
of
communication openings and suction openings of the center plate depicted in
Fig. 3.
[Fig. 5] Fig. 5 is a schematic vertical sectional view showing an example of a
fixed scroll
member in the structure depicted in Fig. 2.
[Fig. 6] Fig. 6 is an elevational view showing an example of the disposition
of
communication paths of the fixed scroll member depicted in Fig. 5.
[Fig. 7] Fig. 7 is a schematic vertical sectional view showing an example of a
structure for
cooling in a hybrid compressor according to an embodiment of the present
invention.
[Fig. 8] Fig. 8 is an elevational view showing an example of the disposition
of
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communication paths of a fixed scroll member in the structure depicted in Fig.
7.
[Fig. 9] Fig. 9 is an elevational view showing an example of the disposition
of
communication openings and suction openings of a center plate in the structure
depicted in
Fig. 7.
Explanation of symbols
[0021]
1: hybrid compressor
2: first compression mechanism
3: second compression mechanism
10: fixed scroll
11: movable scroll
13: drive shaft
14: pulley
15: electromagnetic clutch
16: ball coupling
18: suction port
19: suction path
20: suction chamber
21: discharge hole
22: discharge path
23: discharge port
30: fixed scroll
31: movable scroll
33: drive shaft
34: ball coupling
35: electric motor
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36: rotor
37: motor coil part (stator)
38: stator housing
39: first communication path
40: suction chamber
41: discharge hole
42: discharge path
43: fixed scroll member
50: power supply portion
51: electric motor side suction chamber
52: communication path
53: suction passageway
61: communication path
62: communication opening
63: suction passageway
64: suction opening
65: fixed scroll member
66: portion which is not provided with communication path and communication
opening
67: center plate
68: suction opening
69: suction passageway
70: portion which is not provided with suction opening and suction passageway
The Best mode for carrying out the Invention
[0022] Hereinafter, desirable embodiments of the present invention will be
explained
referring to figures.
Fig. 7 depicts a structure of a hybrid compressor according to an embodiment
of the
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present invention, in correspondence with Fig. 2 aforementioned. Since the
structure
depicted in Figs. I and 2 is applied correspondingly to the basic structure of
the hybrid
compressor depicted in Fig. 7, the explanation will be omitted by attaching
the same symbols
as those attached in Figs. I and 2 to the portions having substantially same
structures as those
shown in Figs. 1 and 2. Hereinafter, points different from the structure shown
in Figs. 1 and
2 will be mainly explained. Where, the arrows depicted in Fig. 7 show an
example of a
refrigerant gas flow at the time of motor operation.
[0023] The structure depicted in Fig. 7 is different from the structure
depicted in Fig. 2, in
that communication paths 61 for sucking the gas to be compressed, which has
been sucked
from suction path 19 into suction chamber 20 of first compression mechanism 2
(in this
embodiment, low-temperature refrigerant gas before compression), into electric
motor side
suction chamber 51, and/or, communication openings 62 which are openings of
the
communication paths 61 at electric motor side suction chamber 51, and, suction
passageways
63 of the refrigerant gas from electric motor side suction chamber 51 to
suction chamber 40 of
second compression mechanism 3, and/or, suction openings 64 which are openings
of the
suction passageways 63 at electric motor side suction chamber 51, are disposed
at positions
apart from each other in the electric motor side suction chamber 51,
particularly, at positions
opposite to each other.
[0024] For example, as an example of a fixed scroll member 65 in this
embodiment is shown
in Fig. 8 in correspondence with Fig. 6 aforementioned, communication paths 61
are provided
only at the upper portion depicted in Fig. 8, and the communication paths 61
are not provided
for the lower and side portions 66 depicted in Fig. 8, in which communication
paths 52 have
been provided in Fig. 6. Namely, in the structure for disposing communication
paths 52 in
Fig. 6, the communication paths 52 are abolished in these portions 66.
Accompanying with
this disposition of communication paths 61, communication openings 62, which
are openings
of the communication paths 61 at electric motor side suction chamber 51, are
also provided
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only at the upper portion depicted in Fig. 8, and they are not provided at
positions
corresponding to the above-described portions 66.
[0025] Further, for example, as an example of a center plate 67 in this
embodiment is shown
in Fig. 9 in correspondence with Fig. 4 aforementioned, suction openings 68
and suction
passageways 69 are provided only at the lower portion depicted in Fig. 9, and
the suction
openings 68 and suction passageways 69 are not provided for the upper portions
70 depicted
in Fig. 9, in which suction openings 56 and suction passageways 53 have been
provided in
Fig. 4. Namely, in the structure for disposing suction openings 56 and suction
passageways
53 in Fig. 4, the suction openings 56 and suction passageways 53 are abolished
in these
portions 70.
[0026] Thus, for electric motor side suction chamber 51, particularly the
positions and/or
numbers of communication openings 62 and suction openings 68 are limited, and
in
particular, they are located at positions opposite to each other. By this, the
refrigerant gas
sucked from communication openings 62 and flowing to suction openings 68 in
electric motor
side suction chamber 51 flows over a wide area without staying, as shown in
Fig. 7.
[0027] Consequently, motor 35 can be appropriately cooled over the entire
area, and a rise
in temperature of the motor 35 at the time of motor operation can be
suppressed low.
Therefore, occurrence of the inconvenience accompanying with an overheating of
the motor
can be avoided, and the available operational range of the motor can be
enlarged.
Industrial Applications of the Invention
[0028] The present invention can be applied to any hybrid compressor into
which a first
compression mechanism and a second compression mechanism are integrally
incorporated
and the second compression mechanism of which is driven by a built-in electric
motor.
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