U.S. patent application number 14/385444 was filed with the patent office on 2015-02-05 for fluid machine.
The applicant listed for this patent is SANDEN CORPORATION. Invention is credited to Shinji Nakamura, Yuuta Tanaka, Hirofumi Wada.
Application Number | 20150033743 14/385444 |
Document ID | / |
Family ID | 49161258 |
Filed Date | 2015-02-05 |
United States Patent
Application |
20150033743 |
Kind Code |
A1 |
Wada; Hirofumi ; et
al. |
February 5, 2015 |
Fluid Machine
Abstract
A fluid machine (29A) including: a casing section (56) having a
suction port (55) into which a working fluid that becomes a high
pressure heated vapor flows; a housing section (54) having a
discharge port (53); and a scroll section (51, 52) driven by the
working fluid suctioned from the suction port (55). A bypass
section (80) including: a bypass passage (81) allowing the suction
port (55) to communicate with the discharge port (53); and a valve
mechanism (83) opening and closing the bypass passage (81), is
supported between the sections (56, 54). When the bypass passage
(81) is opened, the working fluid is circulated while bypassing a
driving section including the scroll section (51, 52) and a sliding
section such as an anti-rotation mechanism (60). Therefore, even
when the working fluid in a liquid phase flows, degradation of
lubricity in the sliding section can be reduced.
Inventors: |
Wada; Hirofumi;
(Isesaki-shi, JP) ; Nakamura; Shinji;
(Isesaki-shi, JP) ; Tanaka; Yuuta; (Isesaki-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SANDEN CORPORATION |
Isesaki-shi |
|
JP |
|
|
Family ID: |
49161258 |
Appl. No.: |
14/385444 |
Filed: |
March 13, 2013 |
PCT Filed: |
March 13, 2013 |
PCT NO: |
PCT/JP2013/057085 |
371 Date: |
September 15, 2014 |
Current U.S.
Class: |
60/670 |
Current CPC
Class: |
F01C 20/26 20130101;
F04B 53/18 20130101; F01C 17/063 20130101; Y02T 10/12 20130101;
F01C 21/18 20130101; F02G 5/00 20130101; F01K 23/065 20130101; F01C
13/04 20130101; F01C 11/008 20130101; F04C 2240/56 20130101; F01C
1/0253 20130101; F01C 1/0215 20130101; Y02T 10/166 20130101 |
Class at
Publication: |
60/670 |
International
Class: |
F01K 23/06 20060101
F01K023/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2012 |
JP |
2012-057341 |
Claims
1. A fluid machine comprising: a suction port into which a working
fluid that becomes a heated vapor and has a high pressure flows; a
driving section which is driven by expansion of the working fluid
suctioned from the suction port; a discharge port from which the
working fluid that has a low pressure while passing through the
driving section flows; and a bypass passage which guides the
working fluid suctioned from the suction port to the discharge port
while allowing the working fluid to bypass a sliding section of the
fluid machine and the driving section.
2. The fluid machine according to claim 1, wherein the bypass
passage is a communication passage which allows the suction port
and the discharge port to communicate with each other.
3. The fluid machine according to claim 2, wherein the suction port
and the discharge port extend in a radial direction of a rotating
shaft of the driving section and are arranged in an axial direction
of the rotating shaft, and wherein the bypass passage extends in
the axial direction of the rotating shaft of the driving section
and allows the suction port and the discharge port to communicate
with each other.
4. The fluid machine according to claim 3, further comprising: a
valve mechanism which opens and closes the bypass passage, wherein
the valve mechanism opens and closes the bypass passage by
displacing a valve body in the radial direction of the rotating
shaft of the driving section.
5. The fluid machine according to claim 1, wherein the fluid
machine includes, as the driving section, a scroll section
including a fixed scroll and an orbiting scroll, and includes, as
the sliding section, an anti-rotation mechanism that prevents the
orbiting scroll from rotating.
6. The fluid machine according to claim 5, wherein the fluid
machine is a scroll type expander, and is incorporated in a Rankine
cycle device which recovers waste heat of an engine for a vehicle
for use.
Description
TECHNICAL FIELD
[0001] The present invention relates to a fluid machine which
includes a driving section that is driven by a working fluid
suctioned from a suction port, and discharges the working fluid
that has passed through the driving section from a discharge
port.
BACKGROUND ART
[0002] Patent Document 1 discloses a fluid machine which includes a
bypass passage that guides a working fluid (refrigerant) suctioned
from a suction port to a discharge port while allowing the working
fluid to bypass a driving section, and a valve mechanism that opens
and closes the bypass passage.
REFERENCE DOCUMENT LIST
Patent Document
[0003] Patent Document 1: Japanese Patent Application Laid-open
Publication No. 2010-236360
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0004] However, the bypass passage of the fluid machine according
to the related art causes the working fluid to circulate while
bypassing the driving section and allows the working fluid that has
bypassed the driving section to be discharged from a discharge port
after passing a part in which a sliding section such as an
anti-rotation mechanism (ball coupling) of the driving section is
disposed.
[0005] Therefore, when the working fluid that is circulated while
bypassing the driving section is in a liquid phase state, the
working fluid (liquid refrigerant) in the liquid phase flows into
the sliding section, and thus a lubricating oil of the sliding
section may be caused to flow. Therefore, there is a possibility
that the lubricity of the sliding section may be degraded.
[0006] An object of the invention is to provide a fluid machine
capable of reducing the degradation of lubricity of a sliding
section even though a working fluid is in a liquid phase when the
working fluid is circulated while bypassing a driving section.
Means for Solving the Problems
[0007] In order to accomplish the object, a fluid machine according
to the invention includes: a suction port into which a working
fluid that becomes a heated vapor and has a high pressure flows; a
driving section which is driven by expansion of the working fluid
suctioned from the suction port; a discharge port from which the
working fluid that has a low temperature while passing through the
driving section flows; and a bypass passage which guides the
working fluid suctioned from the suction port to the discharge port
while allowing the working fluid to bypass a sliding section of the
fluid machine and the driving section.
Effects of the Invention
[0008] In the fluid machine according to the invention, the working
fluid is circulated through the bypass passage while bypassing the
sliding section along with the driving section. Therefore, even
when the working fluid is in a liquid phase, the degradation of
lubricity, which is caused by the flow of a lubricating oil of the
sliding section, can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a diagram illustrating the schematic configuration
of a waste-heat reusing apparatus in an embodiment of the
invention.
[0010] FIG. 2 is a cross-sectional view illustrating a
pump-integrated expander incorporated in the waste-heat reusing
apparatus.
[0011] FIG. 3 is a partial enlarged cross-sectional view
illustrating a bypass section included in the pump-integrated
expander.
MODE FOR CARRYING OUT THE INVENTION
[0012] Hereinbelow, an embodiment of the invention will be
described in detail with reference to the accompanying
drawings.
[0013] FIG. 1 illustrates a waste-heat reusing apparatus 1A for a
vehicle, in which an expander as a fluid machine is
incorporated.
[0014] The waste-heat reusing apparatus 1A is an apparatus that is
mounted in the vehicle along with an engine 10 and recovers waste
heat of the engine 10 for use.
[0015] The waste-heat reusing apparatus 1A includes a Rankine cycle
device 2A, a transmission mechanism 3 which transmits the output of
the Rankine cycle device 2A to the engine 10, and a control unit
4.
[0016] The engine 10 is an internal combustion engine provided with
a water-cooling type cooling device, and the cooling device
includes a coolant circulation passage 11 through which a coolant
is circulated.
[0017] An evaporator 22 of the Rankine cycle device 2A is disposed
in the coolant circulation passage 11 so that the coolant that
absorbs heat from the engine 10 is returned to the engine 10 after
passing through the evaporator 22.
[0018] The Rankine cycle device 2A recovers the waste heat of the
engine 10 from the coolant of the engine 10 and converts the
recovered heat into driving force so as to be output.
[0019] The Rankine cycle device 2A includes a circulation passage
21 through which a working fluid is circulated, and in the
circulation passage 21, the evaporator 22, the expander 23, a
condenser 24, and a pump 25A are arranged in this order along the
flow direction of the working fluid.
[0020] As the working fluid (refrigerant), for example, a substance
which includes a fluorocarbon skeleton as a base is used. In
addition, a lubricating oil circulates along with the working fluid
and has functions of lubricating, sealing, cooling, and the like in
sliding sections of the expander 23 and the pump 25A.
[0021] The evaporator 22 allows heat transfer between the
high-temperature coolant that has absorbed heat from the engine 10
and the working fluid of the Rankine cycle device 2A so that the
working fluid is heated and evaporated (vaporized).
[0022] The expander 23 (fluid machine) is a device which generates
driving force by expanding the working fluid that has a high
temperature and a high pressure through the vaporization in the
evaporator 22, and uses, as an example, a scroll type expander.
[0023] The condenser 24 allows heat exchange between the low
pressure working fluid that has passed through the expander 23 and
the outside air to cool the working fluid so as to be condensed
(liquefied).
[0024] The pump 25A is a mechanical pump and forcibly feeds the
working fluid liquefied in the condenser 24 to the evaporator
22.
[0025] In this manner, the working fluid circulates through the
circulation passage 21 while repeating vaporization, expansion, and
condensation.
[0026] Here, the expander 23 and the pump 25A are connected by a
rotating shaft 28 to be integrated, thereby providing a
pump-integrated expander 29A (fluid machine). That is, the rotating
shaft 28 of the pump-integrated expander 29A functions as the
output shaft of the expander 23 and functions as the driving shaft
of the pump 25A.
[0027] The Rankine cycle device 2A is first started up by driving
the pump 25A by the output of the engine 10, and thereafter, when
the expander 23 generates sufficient driving force, the driving
force of the expander 23 drives the pump 25A.
[0028] The transmission mechanism 3 transmits the torque (axial
torque) of the pump-integrated expander 29A, which is the output of
the Rankine cycle device 2A, to the engine 10 and transmits the
output torque of the engine 10 to the pump-integrated expander 29A
(pump unit) during start-up of the Rankine cycle device 2A.
[0029] The transmission mechanism 3 includes a pulley 31 attached
to the rotating shaft 28 of the pump-integrated expander 29A, a
crank pulley 32 attached to a crankshaft 10a of the engine 10, a
belt 33 wound around the pulley 31 and the crank pulley 32, and an
electromagnetic clutch 34 provided between the rotating shaft 28 of
the pump-integrated expander 29A and the pulley 31.
[0030] By turning on (engaging) and turning off (disengaging) the
electromagnetic clutch 34, power transmission and power
interruption between the engine 10 (crankshaft 10a) and the
rotating shaft 28 of the pump-integrated expander 29A are
switched.
[0031] The control unit 4 having a microcomputer has a function of
controlling the electromagnetic clutch 34, and controls an
operation and a stop of the Rankine cycle device 2A through the on
and off control of the electromagnetic clutch 34.
[0032] That is, when the control unit 4 determines the
establishment of the operating conditions of the Rankine cycle
device 2A, the electromagnetic clutch 34 is engaged (turned on) and
the pump 25A is operated by the engine 10 to start the circulation
of the working fluid (refrigerant), thereby starting up the Rankine
cycle device 2A.
[0033] When the expander 23 is activated and starts to generate a
driving force, a part of the driving force generated by the
expander 23 is used to drive the pump 25A, and the remaining
driving force is transmitted to the engine 10 via the transmission
mechanism 3 to assist the output (driving force) of the engine
10.
[0034] In a case in which the operating conditions of the Rankine
cycle device 2A are not established, the control unit 4 disengages
(turns off) the electromagnetic clutch 34 to stop the circulation
of the working fluid, thereby stopping the Rankine cycle device
2A.
[0035] The evaporator 22 may also act as a device that allows heat
exchange between the working fluid of the Rankine cycle device 2A
and exhaust air of the engine 10 or may also act as a device that
allows heat exchange with the coolant of the engine 10 and allows
heat exchange with exhaust air of the engine 10.
[0036] The expander 23 integrally includes a bypass passage 81 for
circulating the working fluid to bypass a scroll portion provided
as a driving portion and a valve mechanism 83 for opening and
closing the bypass passage 81.
[0037] In addition, for example, the control unit 4 controls the
valve mechanism 83 to be opened so as to open the bypass passage 81
immediately after the start-up of the Rankine cycle device 2A at
which the electromagnetic clutch 34 is engaged so that the working
fluid is circulated while bypassing the scrolls of the expander
23.
[0038] Thereafter, for example, when the refrigerant temperature at
the inlet of the expander 23 exceeds a threshold, in other words,
when the expander 23 can generate driving force, the control unit 4
controls the valve mechanism 83 to be closed to close the bypass
passage 81, to thereby perform a changeover to a state in which the
working fluid is circulated while passing through the scrolls.
[0039] As described above, when the working fluid is circulated
while bypassing the scrolls of the expander 23 immediately after
the start-up of the Rankine cycle device 2A, the pressure in the
evaporator 22 decreases and the evaporation temperature of the
working fluid also decreases. Therefore, the start-up performance
of the Rankine cycle device 2A can be improved. In addition, at the
time of stopping the Rankine cycle device 2A, when the
electromagnetic clutch 34 is disengaged (turned off), the bypass
passage 81 is opened so as to prevent high-speed rotations due to
the residual pressure.
[0040] Next, the structure of the pump-integrated expander 29A will
be described in detail with reference to FIG. 2.
[0041] As described above, the pump-integrated expander 29A is a
fluid machine in which the pump 25A that circulates the working
fluid of the Rankine cycle device 2A and the expander 23 that
generates rotational driving force through the expansion of the
working fluid heated and vaporized in the evaporator 22 are driven
by the common rotating shaft 28, and includes the pulley 31 and the
electromagnetic clutch 34 included in the transmission mechanism
3.
[0042] The expander 23 of the pump-integrated expander 29A includes
a fixed scroll 51 which is disposed in one end portion of the
pump-integrated expander 29A in the axial direction, an orbiting
scroll (movable scroll) 52 assembled to be eccentrically engaged
with the fixed scroll 51, a housing section 54 provided with a
discharge port 53, and a casing section 56 provided with a suction
port 55.
[0043] The fixed scroll 51 includes a disc-like body portion 51a, a
scroll portion (spiral body) 51b uprightly provided on one end
surface of the body portion 51a in a rib shape, and an introduction
port 51c for the working fluid, which is formed to penetrate
through the center of the body portion 51a.
[0044] The housing section 54 is formed in a cylindrical shape with
both ends opened, and includes a first hollow portion 54a into
which the casing section 56 is fitted and which accommodates the
fixed scroll 51 and the orbiting scroll 52, a second hollow portion
54b which supports a large-diameter portion 64 included in a driven
crank mechanism between the orbiting scroll 52 and the rotating
shaft 28, and a third hollow portion 54c which supports the
rotating shaft 28.
[0045] In addition, on the pump 25A side of the first hollow
portion 54a, the discharge port 53 which allows the internal space
(discharge side space of the scrolls) of the first hollow portion
54a to communicate with the external space is formed along the
radial direction of the rotating shaft 28.
[0046] The casing section 56 includes a cylindrical portion 56a
which is provided integrally with the fixed scroll 51 on the inside
and of which the outside is fitted into the first hollow portion
54a, and a working fluid introduction chamber 56b which
communicates with the introduction port 51c of the fixed scroll 51.
The suction port 55 which allows the working fluid introduction
chamber 56b to communicate with the external space of the casing
section 56 is formed along the radial direction of the rotating
shaft 28.
[0047] Here, the discharge port 53 and the suction port 55 are
substantially parallel to each other, extend in a direction at the
same angle from the axis of the rotating shaft 28, and are arranged
in the axial direction of the rotating shaft 28.
[0048] To the suction port 55, one end of a pipe, the other end of
which is connected to the outlet of the evaporator 22, is connected
so that the working fluid heated in the evaporator 22 is introduced
into the expander 23 via the suction port 55.
[0049] The working fluid introduced into the suction port 55 flows
into the working fluid introduction chamber 56b and thereafter is
introduced to the center portion of the fixed scroll 51 via the
introduction port 51c.
[0050] The working fluid introduced to the center portion of the
fixed scroll 51 presses the wall surface of the orbiting scroll 52
to form an expansion chamber, and as the working fluid is
continuously supplied, the expansion chamber moves to the outer
circumferential side, which causes an orbiting motion of the
orbiting scroll 52.
[0051] To the discharge port 53, one end of a pipe, the other end
of which is connected to the inlet of the condenser 24, is
connected so that the working fluid which passes through the
expander 23 is sent to the condenser 24 to be condensed
(liquefied).
[0052] The orbiting scroll 52 includes a disc-like body portion 52a
and a scroll portion (spiral body) 52b uprightly provided on one
end surface of the body portion 52a in a rib shape.
[0053] Here, an anti-rotation mechanism 60 is provided between the
surface of the body portion 52a on the opposite side to the end
surface thereof in which the scroll portion 52b is formed, and a
stepped portion 54d which reaches the second hollow portion 54b
from the first hollow portion 54a of the housing section 54 so that
the orbiting scroll 52 makes orbiting motion as the working fluid
expands while being prevented from rotating by the anti-rotation
mechanism 60.
[0054] As the anti-rotation mechanism 60, there are an Oldham
coupling, a pin and ring coupling, a ball coupling, and the like.
Here, the ball coupling is used, and particularly, a ball coupling
called an EM coupling (refer to "EM coupling for Scroll
Compressors" in NTN TECHNICAL REVIEW No. 68 (2000)) is used. The EM
coupling is constituted by two plates made by integrally
press-forming the race and the ring, steel balls, and the like.
[0055] A cylindrical portion 52c protrudes from the end surface of
the body portion 52a of the orbiting scroll 52 on the anti-rotation
mechanism 60 side, and a drive bearing 61 is provided on the inside
of the cylindrical portion 52c. An eccentric bush 62 is fitted into
the drive bearing 61, and a crankpin hole 62a is formed in the
eccentric bush 62.
[0056] The large-diameter portion 64 is rotatably supported by the
second hollow portion 54b of the housing section 54 via a bearing
63, and a crankpin 64a is uprightly provided on the large-diameter
portion 64 so that the crankpin 64a is parallel to the rotating
shaft 28 and has an axial center shifted from the rotating shaft
28. The crankpin 64a is inserted into the crankpin hole 62a of the
eccentric bush 62.
[0057] The rotating shaft 28 is connected to the large-diameter
portion 64 so that the orbiting motion of the orbiting scroll 52
around the rotating shaft 28 is transmitted as the rotational
driving force of the rotating shaft 28 by the driven crank
mechanism constituted by the eccentric bush 62, the crankpin 64a,
and the large-diameter portion 64.
[0058] In addition, a counterweight (balancing weight) 74 for
reducing occurrence of vibrations of the expander 23 is attached to
the eccentric bush 62.
[0059] Furthermore, in order to restrict the orbiting radius of the
orbiting scroll 52, a restriction hole 64b is provided in the
large-diameter portion 64, and a restriction protrusion 62b fitted
into the restriction hole 64b is provided in the eccentric bush 62.
Therefore, the oscillation of the eccentric bush 62 around the
crankpin 64a is restricted by the engagement between the
restriction hole 64b and the restriction protrusion 62b.
[0060] The rotating shaft 28 is supported by a bearing 65 provided
in the third hollow portion 54c of the housing section 54 and is
supported by a bearing 67 provided in the end portion of a pump
housing 66 connected to the housing section 54 so as to rotate.
[0061] The pump 25A is provided in the pump housing 66. The pump
25A is, as an example, a gear pump, and the gear pump is
constituted by a driving gear (rotating body) that is axially
supported by the rotating shaft 28, a driven shaft that is
rotatably supported in parallel to the rotating shaft 28, and a
driven gear that is axially supported by the driven shaft and is
engaged with the driving gear.
[0062] In the pump housing 66, a pump suction port 66a which
communicates with the suction port of the pump 25A, and a pump
discharge port 66b which communicates with the discharge port of
the pump 25A are formed.
[0063] To the pump suction port 66a, one end of a pipe, the other
end of which is connected to the outlet of the condenser 24, is
connected so that the working fluid condensed (liquefied) in the
condenser 24 is suctioned into the pump 25A. In addition, to the
pump discharge port 66b, one end of a pipe, the other end of which
is connected to the inlet of the evaporator 22, is connected so
that the working fluid condensed (liquefied) in the condenser 24 is
forcibly fed to the evaporator 22 to be evaporated (vaporized).
[0064] As the pump 25A, a well-known pump may be appropriately
employed, and other than the gear pump, a vane pump or the like may
be used.
[0065] On the end portion of the rotating shaft 28 that passes
through the pump housing 66 and extends to the outside, the pulley
31 and the electromagnetic clutch 34 included in the transmission
mechanism 3 are disposed.
[0066] A cylindrical portion 66c in which the rotating shaft 28 is
positioned is formed integrally with the end surface of the pump
housing 66 on the opposite side to the expander 23 side. The
bearing 67 which supports the rotating shaft 28 is disposed on the
front end side of the inside of the cylindrical portion 66c, and a
shaft seal 68 is disposed on the bottom portion side (the expander
23 side) of the cylindrical portion 66c.
[0067] In addition, a clutch plate 71 is attached to the front end
of the rotating shaft 28 that protrudes from the cylindrical
portion 66c, and the pulley 31 is rotatably attached to the outer
circumference of the cylindrical portion 66c via a bearing 72.
[0068] Furthermore, a clutch coil 73 is accommodated in an annular
groove 31a that is formed in the end surface of the pulley 31 on
the expander 23 side and is centered on the rotating shaft 28, and
the electromagnetic clutch 34 is constituted by the clutch plate 71
and the clutch coil 73.
[0069] When the clutch coil 73 is electrically connected, magnetic
attraction occurs and the clutch plate 71 is brought into contact
with the pulley 31 such that the pulley 31 and the clutch plate 71
(rotating shaft 28) are interlocked with each other. As a result,
power is transmitted between the rotating shaft 28 of the
pump-integrated expander 29A and the engine 10 (crankshaft
10a).
[0070] The expander 23 of the pump-integrated expander 29A further
includes a bypass section 80 for guiding the working fluid
suctioned from the suction port 55 to the discharge port 53 while
allowing the working fluid to bypass the driving section (scroll
section) including the fixed scroll 51 and the orbiting scroll 52,
and the sliding sections such as the anti-rotation mechanism
60.
[0071] The bypass section 80 includes a holder 82 in which the
bypass passage 81 is formed, and the valve mechanism 83 which is
supported by the holder 82 and opens and closes the bypass passage
81, and is supported between the casing section 56 provided with
the suction port 55 and the housing section 54 provided with the
discharge port 53.
[0072] In addition, the valve mechanism 83 is a solenoid valve
having a coil 83d. A shim 96 is fixed between the holder 82 and the
casing section 56 and between the housing section 54 and the casing
section 56.
[0073] Hereinbelow, details of the bypass section 80 will be
described with reference to FIG. 3.
[0074] The holder 82 includes a front end portion 82a in which the
bypass passage 81 is formed and a base end portion 82b which holds
the coil 83d of the valve mechanism 83 and the like, and the front
end portion 82a is supported between the casing section 56 and the
housing section 54 in the axial direction of the rotating shaft
28.
[0075] An accommodation space 91 for supporting the front end
portion 82a of the holder 82 is provided between a part in which
the suction port 55 of the casing section 56 is formed and a part
in which the discharge port 53 of the housing section 54 is formed.
The accommodation space 91 is a space which is surrounded by the
casing section 56 and the housing section 54 with a bottom and is
open to the radially outer side of the rotating shaft 28.
[0076] A suction side communication passage 92 which communicates
with the suction port 55 is open to the surface of the
accommodation space 91 that is on the casing section 56 side and
configured to support the front end portion 82a of the holder 82 in
the axial direction. In addition, a discharge side communication
passage 93 which communicates with the discharge port 53 is open to
the surface of the accommodation space 91 that is on the housing
section 54 side and configured to support the front end portion 82a
in the axial direction.
[0077] In addition, the bypass passage 81 which extends in the
axial direction of the rotating shaft 28 is formed in the front end
portion 82a of the holder 82, and in a state in which the front end
portion 82a is supported between the casing section 56 and the
housing section 54 in the axial direction of the rotating shaft 28,
one end of the bypass passage 81 is connected to the suction side
communication passage 92 and the other end of the bypass passage 81
is connected to the discharge side communication passage 93,
thereby forming a bypass passage of the working fluid.
[0078] As described above, the bypass section 80 (holder 82) is
disposed between the suction port 55 and the discharge port 53, and
the suction port 55 and the discharge port 53 directly communicate
with each other through the bypass passage 81 formed in the holder
82. In other words, the bypass passage 81 formed in the holder 82
is a communication passage that extends in the axial direction of
the rotating shaft 28 and allows the suction port 55 and the
discharge port 53 to directly communicate with each other.
[0079] A part of the holder 82 in which the end portion of the
bypass passage 81 on the casing section 56 side is open forms a
cylindrical protrusion 82c which protrudes in a cylindrical shape
along the direction parallel to the axis of the rotating shaft 28,
and the bypass passage 81 extends in the axial center of the
cylindrical protrusion 82c.
[0080] On the other hand, the suction side communication passage 92
has a fitting hole (enlarged diameter portion) 92a having a
diameter into which the cylindrical protrusion 82c is fitted, on
the holder 82 side (the housing section 54 side). That is, the
suction side communication passage 92 is formed to have
substantially the same diameter as the bypass passage 81 from the
suction port 55 side and in the middle of the passage, the diameter
thereof is enlarged to a diameter into which the outer
circumference of the cylindrical protrusion 82c is fitted.
[0081] In addition, an annular groove 82f is formed in the outer
circumference of the cylindrical protrusion 82c and a seal member
(O-ring) 94 formed of an elastic material such as rubber in an
annular shape is fitted into the annular groove 82f. When the
cylindrical protrusion 82c is fitted into the fitting hole 92a, the
gap between the outer circumference of the cylindrical protrusion
82c and the inner circumference of the fitting hole 92a of the
suction side communication passage 92 is sealed by the seal member
94.
[0082] That is, by fitting the cylindrical protrusion 82c into the
fitting hole 92a of the suction side communication passage 92, the
bypass passage 81 is allowed to communicate with the suction port
55, and the position of the holder 82 in the radial direction of
the rotating shaft 28 is determined with respect to the suction
side communication passage 92 so that the gap between the
cylindrical protrusion 82c of the holder 82 and the fitting hole
92a of the casing section 56, in other words, the suction port 55
side of the bypass passage 81, is sealed by the cylindrical
seal.
[0083] Abutment between the holder 82 and the casing section 56 in
the axial direction of the rotating shaft 28 is performed between a
flat surface portion 82e of the root portion of the cylindrical
protrusion 82c and a flat surface portion 56c of the casing section
56 in which the suction side communication passage 92 is open. In
addition, between the holder 82 and the casing section 56 and
between the housing section 54 and the casing section 56, the shim
96 which is a fitting strip made of, for example, metal is fixed.
By the shim, the gap between the fixed scroll 51 and the orbiting
scroll 52 in the axial direction of the rotating shaft 28 is
adjusted.
[0084] A base portion 82g which forms an abutment surface parallel
to the transverse cross-section of the rotating shaft 28 protrudes
from a part of the holder 82 in which the end portion of the bypass
passage 81 on the housing section 54 side is open, and a recessed
portion 54e into which the base portion 82g is loosely inserted and
which has a bottom surface (flat surface portion), which is
parallel to the end surface (flat surface portion) of the base
portion 82g and to which the discharge side communication passage
93 is open, is formed in the housing section 54.
[0085] In addition, in a case in which the holder 82 is supported
between the housing section 54 and the casing section 56, when the
base portion 82g is loosely inserted into the recessed portion 54e,
the bypass passage 81 on the holder 82 side and the discharge side
communication passage 93 on the housing section 54 side communicate
with each other, and the bypass passage 81 is connected to the
discharge port 53 via the discharge side communication passage
93.
[0086] That is, the bypass passage 81 is formed from the front end
of the cylindrical protrusion 82c to the base portion 82g (flat
surface portion), and by supporting the holder 82 between the
housing section 54 and the casing section 56, the suction port 55
and the discharge port 53 are allowed to communicate with each
other by the bypass passage 81.
[0087] An annular groove 54f is formed in the bottom surface of the
recessed portion 54e so as to surround the opening of the discharge
side communication passage 93, and a seal member 95 formed of an
elastic material such as rubber is fitted into the groove 54f so
that the abutment surface between the holder 82 and the housing
section 54 is surrounded and sealed by the seal member 95. That is,
the periphery of the connection portion between the bypass passage
81 on the holder 82 side and the discharge side communication
passage 93 on the housing section 54 side is sealed by a flat seal.
In other words, the bypass passage 81 and the discharge port 53 are
sealed by the flat seal.
[0088] The seal member 95 generates a force to bias the holder 82
toward the casing section 56 side by being compressed by the holder
82, and accordingly, the holder 82 abuts on the casing section 56
side and the position of the holder 82 in the axial direction of
the rotating shaft 28 is determined with respect to the casing
section 56.
[0089] In addition, the holder 82 of the bypass section 80
integrally includes the valve mechanism (pilot type solenoid valve)
83 which is a solenoid valve that opens and closes the bypass
passage 81.
[0090] The bypass passage 81 includes a passage 81a that extends
from the casing section 56 side in parallel to the axial direction
of the rotating shaft 28 and a passage 81b that extends from the
housing section 54 side in parallel to the axial direction of the
rotating shaft 28, the passage 81a is formed at a position farther
from the rotating shaft 28 than the passage 81b, and the passages
81a and 81b communicate with each other through a passage 81c that
extends in the radial direction of the rotating shaft 28.
[0091] In the passage 81c, a valve body 83a is moved from the
outside to the inside in the radial direction of the rotating shaft
28 and is seated, a seat portion 81d for blocking the passage 81c
(bypass passage 81) in the seated state is formed, and a plunger
83b is supported on the radially outer side in relation to the seat
portion 81d to be displaced along the radial direction.
[0092] The plunger 83b is biased toward the seat portion 81d (in a
direction approaching the rotating shaft 28) by a coil spring
(elastic body) 83c and is displaced in a direction away from the
seat portion 81d (rotating shaft 28) by the magnetic force of the
coil (solenoid) 83d against the biasing force of the coil spring
83c.
[0093] Here, the base end portion 82b of the holder 82 which
accommodates the coil 83d is exposed to the outside of the casing
section 56 and the housing section 54, and in the part exposed to
the outside, a terminal (not illustrated) for electrical connection
to the coil 83d is provided.
[0094] The valve body 83a is supported between the plunger 83b and
the seat portion 81d to be displaced in the same direction (the
radial direction of the rotating shaft 28) as the forward and
backward direction of the plunger 83b.
[0095] A pilot passage 83e which penetrates through the valve body
83a in the displacement direction thereof is formed in the valve
body 83a, and a pilot valve 83f which blocks the opening of the
pilot passage 83e on the plunger 83b side is formed in the front
end of the plunger 83b.
[0096] In addition, in a state in which the coil 83d is not
electrically connected, the plunger 83b is displaced toward the
seat portion 81d by the biasing force of the coil spring 83c and
thus the valve body 83a pressed by the plunger 83b is seated on the
seat portion 81d. In addition, the opening of the pilot passage 83e
on the plunger 83b side is blocked by the pilot valve 83f,
resulting in a valve closed state in which the flow of the working
fluid via the bypass passage 81 is inhibited.
[0097] When the coil 83d is electrically connected in the closed
state, the plunger 83b becomes separated from the valve body 83a
seated on the seat portion 81d by the magnetic force of the coil
83d, and thus the pilot valve 83f becomes separated from the
opening of the pilot passage 83e on the plunger 83b side such that
the pilot passage 83e is opened.
[0098] When the pilot passage 83e is opened, the pressure in the
space (main valve chamber) interposed between the valve body 83a
and the plunger 83b decreases to the pressure on the discharge port
53 side, and a high pressure on the suction port 55 side is applied
to the lower side of the outside of the valve body 83a. Therefore,
due to the pressure difference, the valve body 83a is lifted and
becomes separated from the seat portion 81d, resulting in a valve
open state in which the working fluid flows via the bypass passage
81. While the electrical connection to the coil 83d is continued,
the valve open state is maintained.
[0099] When the electrical connection to the coil 83d is
interrupted in the valve open state (electrically connected state),
the plunger 83b is displaced in a direction approaching the seat
portion 81d by the biasing force of the coil spring 83c to block
the pilot passage 83e, and furthermore, the valve body 83a is
pressed by the plunger 83b and is displaced in the direction
approaching the seat portion 81d. Therefore, the valve body 83a is
seated on the seat portion 81d and returns to the valve closed
state. While the non-electrical connection to the coil 83d is
continued, the valve closed state is maintained.
[0100] As described above, the valve mechanism 83 which opens and
closes the bypass passage 81 is a so-called pilot type solenoid
valve constituted by the valve body 83a, the plunger 83b, the coil
spring 83c, the coil 83d, and the like.
[0101] The valve mechanism 83 is not limited to the pilot type
solenoid valve which drives a valve body by using a pressure
difference of a fluid, and may employ a direct acting solenoid
valve which mechanically opens and closes a valve body by driving a
movable core.
[0102] When the control unit 4 allows the coil 83d to be
electrically connected and thus allows the valve mechanism 83 to
enter the valve open state so as to cause the suction port 55 and
the discharge port 53 to communicate with each other through the
bypass passage 81, for example, immediately after the start-up of
the Rankine cycle device 2A to which the electromagnetic clutch 34
is engaged, a bypass pathway, in which the working fluid that has
flowed into the expander 23 from the suction port 55 is guided to
the discharge port 53 as it is via the bypass passage 81 and is
discharged to the outside of the expander 23, is open. Thus, the
working fluid is circulated while bypassing the scrolls 51 and 52
provided as the driving section, and the sliding sections such as
the anti-rotation mechanism 60 of the orbiting scroll 52 and the
drive bearing 61.
[0103] As described above, in the bypass pathway formed by the
bypass passage 81, sliding sections such as the anti-rotation
mechanism 60 of the orbiting scroll 52 and the drive bearing 61 are
absent. Therefore, even when the working fluid in a gas-liquid
mixed state or in a liquid phase state is circulated when the
bypass passage 81 is open, leakage of the lubricating oil from the
sliding sections can be reduced, and thus the lubricity of the
sliding sections can be sufficiently kept.
[0104] Here, with regard to the arrangement of the pump-integrated
expander 29A (expander 23), the direction of the suction port 55
and the discharge port 53 with respect to the vertical or
horizontal direction is not limited to the above-described
arrangement. However, it is preferable that the directions be set
to a direction in which the leakage of the lubricating oil from the
sliding sections can be reduced as much as possible when the bypass
passage 81 is opened. Specifically, by installing the
pump-integrated expander 29A (expander 23) so that the axial lines
of the suction port 55 and the discharge port 53 are horizontal or
descend in a direction from the inside to the outside of the radial
direction of the rotating shaft 28, the leakage of the lubricating
oil from the sliding sections, in other words, the flow of the
working fluid in a liquid phase into the sliding sections can be
effectively reduced. Particularly, when the axial lines of the
suction port 55 and the discharge port 53 are provided to be
vertically downward in the direction from the inside to the outside
of the radial direction of the rotating shaft 28, the working fluid
in the liquid phase can be prevented as much as possible from
flowing away from the bypass pathway and flowing into the sliding
sections.
[0105] In addition, since the above-described expander 23 is
provided integrally with the bypass passage 81 and the valve
mechanism 83 which opens and closes the bypass passage 81, compared
to a case in which a bypass passage provided with a valve mechanism
is connected to a pipe for circulating a working fluid, the
circulation circuit of the working fluid in the Rankine cycle
device 2A can be simplified.
[0106] In addition, since the holder 82 (bypass section 80) in
which the bypass passage 81 is formed and the valve mechanism 83 is
integrally provided is supported between the casing section 56 in
which the suction port 55 is formed and the housing section 54 in
which the discharge port 53 is formed, the bypass passage 81 and
the valve mechanism 83 can be provided in the expander 23 (fluid
machine) with a simple structure. Therefore, the processing of the
expander 23 can be simplified and an increase in the axial length
of the expander 23 can be reduced.
[0107] In addition, since the movement direction of the plunger 83b
and the valve body 83a in the valve mechanism 83 is set to be in
the radial direction of the rotating shaft 28, the movement spaces
of the plunger 83b and the valve body 83a are long in the radial
direction of the rotating shaft 28, and compared to a case in which
the movement direction thereof is set to a direction parallel to
the rotating shaft 28, the axial length of the expander 23 can be
reduced.
[0108] Furthermore, since the coil (solenoid) 83d of the valve
mechanism 83 is accommodated in the base end portion 82b of the
holder 82 which is exposed to the outside of the casing section 56
and the housing section 54, heat dissipation from the coil 83d can
be efficiently performed.
[0109] In addition, since the coil (solenoid) 83d which is a large
component among the components constituting the valve mechanism 83
is disposed on the outside of the part interposed between the
casing section 56 and the housing section 54, there is no need to
secure the accommodation space of the coil (solenoid) 83d to be in
the part interposed between the casing section 56 and the housing
section 54, and for this reason, the axial length of the expander
23 can also be reduced.
[0110] In addition, in the structure in which the holder 82 (bypass
section 80) is supported between the casing section 56 and the
housing section 54, one connection portion of the bypass passage 81
is sealed by a cylindrical seal and the other connection portion
thereof is sealed by a flat seal. Therefore, the holder 82 (bypass
section 80) can be easily positioned while blocking the leakage
pathway of the working fluid.
[0111] While the contents of the invention have been described in
detail with reference to the preferred embodiments, it is
understood by those skilled in the art that various modifications
can be made on the basis of the technical spirit and scope of the
invention.
[0112] For example, the expander 23 illustrated in FIG. 2 is
provided integrally with the pump 25A. However, a generator may be
provided integrally with the expander 23 instead of the pump 25A or
together with the pump 25A. Furthermore, the above-described bypass
structure may also be applied to an expander which does not include
the pump 25A or the generator.
[0113] In addition, the expander 23 may also be a rotary expander
which includes a rotary piston as a driving section other than the
scroll type.
[0114] In addition, the cylindrical protrusion 82c of the holder 82
may be provided on a surface that opposes the housing section 54 so
as to fit the cylindrical protrusion 82c into the discharge side
communication passage 93, and the base portion 82g of the holder 82
may be provided on a surface that opposes the casing section 56 so
as to allow the base portion 82g to abut on the surface of the
casing section 56 in which the suction side communication passage
92 is open. In other words, the connection portion of the bypass
passage 81 on the housing section 54 side may be sealed by a
cylindrical seal, and the connection portion of the bypass passage
81 on the casing section 56 side may be sealed by a flat seal.
[0115] In addition, the extension direction of the suction port 55
and the discharge port 53 is not limited to the radial direction of
the rotating shaft 28, and for example, the suction port 55 may be
configured to extend in the axial direction of the rotating shaft
28.
[0116] In addition, the bypass passage 81 may be configured not
only to allow the suction port 55 and the discharge port 53 to
directly communicate with each other, but also to, for example,
connect the working fluid introduction chamber 56b to the discharge
port 53, or to connect the suction port 55 or the working fluid
introduction chamber 56b to a discharge side space immediately
before the discharge port 53. That is, the bypass passage 81 can be
modified in a range in which the bypass pathway that does not pass
through the sliding sections such as the anti-rotation mechanism 60
of the orbiting scroll 52 and the drive bearing 61 is formed.
[0117] In addition, the fluid machine is not limited to the
expander 23 and may be a compressor.
[0118] Furthermore, the fluid machine such as the expander 23 is
not limited to being incorporated in the waste-heat reusing
apparatus (Rankine cycle device).
REFERENCE SYMBOL LIST
[0119] 1A Waste-heat reusing apparatus [0120] 2A Rankine cycle
device [0121] 10 Engine [0122] 21 Circulation passage [0123] 22
Evaporator [0124] 23 Expander [0125] 24 Condenser [0126] 25A Pump
[0127] 28 Rotating shaft [0128] 29A Pump-integrated expander (fluid
machine) [0129] 31 Pulley [0130] 34 Electromagnetic clutch [0131]
51 Fixed scroll [0132] 52 Orbiting scroll [0133] 53 Discharge port
[0134] 54 Housing section [0135] 55 Suction port [0136] 56 Casing
section [0137] 60 Anti-rotation mechanism [0138] 62 Eccentric bush
[0139] 80 Bypass section [0140] 81 Bypass passage (communication
passage) [0141] 82 Holder [0142] 82c Cylindrical protrusion [0143]
83 Valve mechanism [0144] 83a Valve body [0145] 83b Plunger [0146]
83c Coil spring [0147] 83d Coil [0148] 92 Suction side
communication passage [0149] 92a Fitting hole (enlarged diameter
portion) [0150] 93 Discharge side communication passage
* * * * *