U.S. patent application number 15/353135 was filed with the patent office on 2017-05-25 for variable displacement type swash plate compressor.
This patent application is currently assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. The applicant listed for this patent is KABUSHIKI KAISHA TOYOTA JIDOSHOKKI. Invention is credited to Hiroyuki KOBAYASHI, Hiromichi OGAWA, Takahiro SUZUKI, Shinya YAMAMOTO, Yusuke YAMAZAKI.
Application Number | 20170145997 15/353135 |
Document ID | / |
Family ID | 58693862 |
Filed Date | 2017-05-25 |
United States Patent
Application |
20170145997 |
Kind Code |
A1 |
OGAWA; Hiromichi ; et
al. |
May 25, 2017 |
VARIABLE DISPLACEMENT TYPE SWASH PLATE COMPRESSOR
Abstract
A variable displacement type swash plate compressor includes a
housing having therein a swash plate chamber and a plurality of
cylinder bores, a drive shaft, a swash plate, and a link mechanism
and a plurality of pistons. The compressor further includes a
partitioning body, a movable body, a control chamber, a control
mechanism and a connecting mechanism. The connecting mechanism
includes first and second arms, a traction portion, and a link pin.
The first and second arms have first and second guide surfaces that
are placed in contact with the link pin. The link pin is held by
the traction portion so as to be rollable on the first and second
guide surfaces, respectively. A restrictor is provided on the ling
pin or in the first and second arms so as to prevent the link pin
from moving in a direction of an axis thereof.
Inventors: |
OGAWA; Hiromichi;
(Aichi-ken, JP) ; YAMAMOTO; Shinya; (Aichi-ken,
JP) ; SUZUKI; Takahiro; (Aichi-ken, JP) ;
KOBAYASHI; Hiroyuki; (Aichi-ken, JP) ; YAMAZAKI;
Yusuke; (Aichi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA TOYOTA JIDOSHOKKI |
Aichi |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Aichi
JP
|
Family ID: |
58693862 |
Appl. No.: |
15/353135 |
Filed: |
November 16, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 27/1804 20130101;
F04B 27/1054 20130101; F04B 27/0878 20130101; F04B 27/1063
20130101; F04B 27/1072 20130101; F04B 39/12 20130101; F04B 49/125
20130101 |
International
Class: |
F04B 27/18 20060101
F04B027/18; F04B 39/12 20060101 F04B039/12; F04B 49/12 20060101
F04B049/12; F04B 27/08 20060101 F04B027/08 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 24, 2015 |
JP |
2015-228850 |
Claims
1. A variable displacement type swash plate compressor comprising:
a housing having therein a swash plate chamber and a plurality of
cylinder bores; a drive shaft rotatably supported in the housing; a
swash plate mounted on the drive shaft for rotation therewith in
the swash plate chamber; a link mechanism connecting the drive
shaft and the swash plate and permitting changing of an inclination
angle of the swash plate with respect to a direction perpendicular
to an axis of rotation of the drive shaft; a plurality of pistons
received in the respective cylinder bores so as to form respective
compression chambers and reciprocally movable with the rotation of
the swash plate for a length of stroke determined by the
inclination angle of the swash plate; a partitioning body mounted
on the drive shaft for rotation therewith in the swash plate
chamber; a movable body that is mounted on the drive shaft for
rotation therewith and movable relative to the partitioning body
along the axis of rotation in the swash plate chamber to thereby
change the inclination angle of the swash plate; a control chamber
that is formed between the partitioning body and the movable body
and causes the movable body to move with a pressure in the control
chamber; a control mechanism controlling the pressure in the
control chamber; and a connecting mechanism connecting the swash
plate and the movable body so that the movable body pulls the swash
plate to increase the inclination angle with an increase of the
pressure in the control chamber, wherein the swash plate has a top
dead center portion that permits one of the pistons to be located
at the top dead center, wherein a plane that passes through the top
dead center portion and the axis of rotation is defined as an
imaginary plane, wherein the connecting mechanism includes a first
arm that extends from the movable body toward the swash plate and
is disposed on one side of the imaginary plane, a second arm that
extends from the movable body toward the swash plate and disposed
on the other side of the imaginary plane, and a traction portion
that is projected from the swash plate toward the movable body
between the first arm and the second arm, and a link pin that
connects the first arm and the second arm of the movable body and
the traction portion, wherein the first arm has a first guide
surface facing away from the swash plate and the second arm has a
second guide surface facing away from the swash plate, wherein the
first guide surface and the second guide surface are placed in
contact with the link pin, wherein the link pin is held by the
traction portion so as to be rollable on the first guide surface
and the second guide surface, and wherein a restrictor is provided
on the link pin or in the first and second arms so as to prevent
the link pin from moving in a direction of an axis thereof.
2. The variable displacement type swash plate compressor according
to claim 1, wherein the first arm includes a first facing portion
that faces one end surface of the link pin and the second arm
includes a second facing portion that faces the other end surface
of the link pin, and wherein the first facing portion and the
second facing portion cooperate to form the restrictor.
3. The variable displacement type swash plate according to claim 2,
wherein peripheries of the end surfaces of the link pin are
chamfered.
4. The variable displacement type swash plate according to claim 1,
wherein the traction portion has a support hole in which the link
pin is rotatably supported, wherein the support hole has a diameter
that is increased axially outward from the middle toward the
opposite ends of the support hole.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a variable displacement
type swash plate compressor.
[0002] Japanese Unexamined Patent Application Publication No.
2014-190265 discloses a conventional variable displacement type
swash plate compressor (hereinafter simply referred to as
compressor). The compressor includes a housing, a drive shaft, a
swash plate, a link mechanism and a plurality of pistons. The
housing has therein a swash plate chamber and a plurality of
cylinder bores. The drive shaft is rotatably supported in the
housing. The swash plate is mounted on the drive shaft for rotation
therewith in the swash plate chamber. The link mechanism is
provided between the drive shaft and the swash plate and permits
changing of an inclination angle of the swash plate relative to an
imaginary plane extending perpendicularly to the axis of rotation
of the drive shaft. Each piston is received in its corresponding
cylinder bore and reciprocally movable in the cylinder bore with a
stroke length that is determined by the inclination angle of the
swash plate thereby to form a compression chamber in the cylinder
bore.
[0003] The compressor further includes a partitioning body, a
movable body, a control chamber, and a control mechanism. The
partitioning body and the movable body are disposed in the swash
plate chamber and mounted on the drive shaft for rotation
therewith. The movable body is movable relative to the partitioning
body in the axial direction of the drive shaft so as to change the
inclination angle of the swash plate. The control chamber is
defined between the partitioning body and the movable body and
causes the movable body to be moved with its internal pressure. The
control mechanism controls the pressure in the control chamber.
[0004] The movable body is connected to the swash plate through the
link mechanism. Specifically, the link mechanism includes a first
arm and a second arm that are provided in the movable body, and a
traction portion that is formed in the swash plate. The first and
second arms extend toward the swash plate, and the traction portion
projects toward the movable body in a space between the first and
second arms.
[0005] The first arm has therethrough a circular first hole and the
second arm has a circular second hole, respectively. The traction
portion includes a pin having one end thereof inserted through the
first hole and the other end thereof through the second hole,
respectively.
[0006] The movement of the movable body away from the swash plate
in the axial direction of the drive shaft by an increased pressure
in the control chamber is transmitted through the first and second
holes of the first and second arms and the link pin held by the
traction portion. As a result, the movable body pulls the swash
plate thereby to increase the inclination angle of the swash
plate.
[0007] According to the compressor disclosed in the Publication,
the relative positional relation between the link pin and the first
and second holes remains constant without being affected by the
change of the inclination angle of the swash plate. In order to
enhance the freedom of setting the pattern of changing of the
inclination angle of the swash plate, it may be contemplated, for
example, to form the first and second holes into elongated holes
and to form a first guide surface that is contactable with the link
pin on a side thereof opposite to the swash plate and a second
guide surface that is contactable with the link pin on the side
thereof opposite to the swash plate so that the link pin is
disposed slidably and reciprocally on the first and second guide
surfaces with the change of the inclination angle of the swash
plate.
[0008] In the compressor having such configuration, however, there
is a fear that changing the inclination angle of the swash plate
may not take place smoothly because of the friction occurring
between the link pin, which is fixed to the traction portion so as
to prevent the link pin from falling off from the traction portion,
and the first and second guide surface on which the link pin
slides.
[0009] The present invention, which has been made in light of the
above described problems, is directed to providing a variable
displacement type swash plate compressor that permits smooth
changing of the inclination angle of the swash plate.
SUMMARY OF THE INVENTION
[0010] In accordance with an aspect of the present invention, there
is provided a swash plate type variable displacement compressor
including a housing having therein a swash plate chamber and a
plurality of cylinder bores, a drive shaft rotatably supported in
the housing, a swash plate mounted on the drive shaft for rotation
therewith in the swash plate chamber, and a link mechanism
connecting the drive shaft and the swash plate and permitting
changing of an inclination angle of the swash plate with respect to
a direction perpendicular to an axis of rotation of the drive
shaft. The compressor further includes a plurality of pistons
received in the respective cylinder bores so as to form respective
compression chamber and reciprocally movable with the rotation of
the swash plate for a length of stroke determined by the
inclination angle of the swash plate, a partitioning body mounted
on the drive shaft for rotation therewith in the swash plate
chamber, a movable body that is mounted on the drive shaft for
rotation therewith and movable relative to the partitioning body
along the axis of rotation in the swash plate chamber to thereby
change the inclination angle of the swash plate, a control chamber
that is formed between the partitioning body and the movable body,
and cause the movable body to move with a pressure in the control
chamber, and a control mechanism controlling the pressure in the
control chamber, and a connecting mechanism connecting the swash
plate and the movable body, so that the movable body pulls the
swash plate to increase the inclination angle with an increase of
the pressure in the control chamber. The swash plate has a top dead
center portion that permits one of the pistons to be located at the
top dead center. A plane that passes through the top dead center
portion and the rotation axis is defined as an imaginary plane. The
connecting mechanism includes a first arm that extends from the
movable body toward the swash plate and is disposed on one side of
the imaginary plane, a second arm that extends from the movable
body toward the swash plate and disposed on the other side of the
imaginary plane, a traction portion that is projected from the
swash plate toward the movable body between the first arm and the
second arm. The first arm has a first guide surface facing away
from the swash plate and the second arm has a second guide surface
facing away from the swash plate. The first guide surface and the
second guide surface are placed in contact with the link pin. The
link pin is held by the traction portion so as to be rollable on
the first guide surface and the second guide surface. A restrictor
is provided on opposite sides of the link pin with respect to the
imaginary plane so as to prevent the link pin from moving in a
direction of an axis thereof.
[0011] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a longitudinal cross-sectional view of a
compressor according to a first embodiment of the present
invention, showing a state of the compressor at its maximum
displacement;
[0013] FIG. 2 is a longitudinal cross-sectional view of the
compressor of FIG. 1, showing a state of the compressor in its
minimum displacement;
[0014] FIG. 3 is a schematic diagram of a control mechanism of the
compressor of FIG. 1;
[0015] FIG. 4 is a fragmentary schematic side view of the
compressor of FIG. 1 at its maximum displacement;
[0016] FIG. 5 is a fragmentary schematic side view of the
compressor of FIG. 1 at its minimum displacement;
[0017] FIG. 6 is a fragmentary perspective view of the compressor
as viewed in the direction of arrow Z in FIG. 5;
[0018] FIG. 7A is a perspective view of a swash plate of the
compressor of FIG. 1;
[0019] FIG. 7B is a front view of the swash plate as viewed in the
arrow direction of arrow Y in FIG. 7A;
[0020] FIG. 8 is a perspective view of a movable body of the
compressor of FIG. 1;
[0021] FIG. 9 is a perspective view of the movable body as viewed
in the direction of arrow Z in FIG. 5;
[0022] FIG. 10A is a front view of the movable body;
[0023] FIG. 10B is a side view of the movable body;
[0024] FIG. 11 is a partially enlarged view of FIG. 10B;
[0025] FIG. 12 is a fragmentary cross-sectional view of the movable
body taken along line XII-XII in FIG. 11;
[0026] FIG. 13 is a fragmentary side view of the compressor,
illustrating a procedure for assembling a link mechanism, the swash
plate and the movable body
[0027] FIG. 14 is a side view of a movable body of a compressor
according to a second embodiment of the present invention;
[0028] FIG. 15 is similar to FIG. 12, but showing a fragmentary
cross-sectional view of the movable body taken along line XV-XV in
FIG. 14;
[0029] FIG. 16 is also similar to FIG. 12, but showing a
fragmentary cross-sectional view of a movable body of a compressor
according to a third embodiment of the present invention; and
[0030] FIG. 17 is a fragmentary cross-sectional view of the movable
body of FIG. 16, showing a state in which the swash plate is
misaligned with respect to rotation axis.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0031] The following will describe a variable displacement type
swash plate compressor according to first, second and third
embodiments of the present invention, respectively, with reference
to the accompanying drawings.
[0032] Referring to FIGS. 1 and 2, there is shown a variable
displacement type swash plate compressor (hereinafter simply
referred to as the compressor) according to the first embodiment.
The compressor according to the present embodiment employs a
double-headed piston. The compressor is mounted on a vehicle and
forms a part of a refrigeration circuit of an air conditioner of
the vehicle. In FIGS. 1 and 2, the left side and right side of the
drawings will be referred to as the front and rear of the
compressor, respectively.
[0033] The compressor includes a housing 1, a drive shaft 3 having
an axis of rotation O1 extending in the longitudinal direction of
the compressor, a swash plate 5, a link mechanism 7, a plurality of
pistons 9, and an actuator 13. As shown in FIG. 3, the compressor
further includes a control mechanism 15.
[0034] Referring to FIGS. 1 and 2, the housing 1 includes a first
housing member 17, a second housing member 19, a first cylinder
block 21, a second cylinder block 23, a first valve-forming plate
39 and a second valve-forming plate 41.
[0035] The first housing member 17 is formed with a boss 17A
projecting frontward and having therein a shaft seal device 25. The
first housing member 17 has therein an annular first suction
chamber 27A and an annular first discharge chamber 29A. The first
suction chamber 27A is located radially inward of the first housing
member 17, and the first discharge chamber 29A is located radially
outward of the first suction chamber 27A in the first housing
member 17.
[0036] The first housing member 17 further has therein a first
front passage 18A. The first front passage 18A is in communication
at the front end thereof with the first discharge chamber 29A and
is opened at the rear end thereof to the rear end of the first
housing member 17.
[0037] A part of the aforementioned control mechanism 15 is formed
in the second housing member 19. The second housing member 19 has
therein an annular second suction chamber 27B, an annular second
discharge chamber 29B, and a pressure control chamber 31. The
pressure control chamber 31 is located in the center of the second
housing member 19. The second suction chamber 27B is located
radially outward of the pressure control chamber 31 in the second
housing member 19. The second discharge chamber 29B is located
radially outward of the second suction chamber 27B in the second
housing member 19.
[0038] The second housing member 19 further has therein a first
rear passage 20A. The first rear passage 20A is in communication at
the rear end thereof with the second discharge chamber 29B and
connected at the front end thereof to the front end of the second
housing member 19.
[0039] The first cylinder block 21 is disposed on the front side of
the compressor between the first housing member 17 and the second
cylinder block 23. The first cylinder block 21 has therein a
plurality of first cylinder bores 21A that extends along the axis
of rotation O1 of the drive shaft 3. The first cylinder bores 21A
are spaced angularly at a regular interval around the drive shaft
3. A first shaft hole 21B is formed through the first cylinder
block 21, and the drive shaft 3 is inserted through the first shaft
hole 21B. A first slide bearing 22A is provided in the first shaft
hole 21B.
[0040] The first cylinder block 21 further has at the center
thereof a first recess 21C that is formed coaxially with the first
shaft hole 21B and communicates with the first shaft hole 21B. The
first recess 21C has an inner diameter that is larger than that of
the first shaft hole 21B. A first thrust bearing 35A is provided in
the first recess 21C.
[0041] The first cylinder block 21 has therein a first connecting
passage 37A and a second front passage 18B. The front ends of the
first connecting passage 37A and the second front passage 18B are
opened to the front end of the first cylinder block 21 and the rear
ends of the first connecting passage 37A and the second front
passage 18B are opened to the rear end of the first cylinder block
21.
[0042] The second cylinder block 23 is disposed between the first
cylinder block 21 and the second housing member 19 in the rear part
of the compressor. The second cylinder block 23 and the first
cylinder block 21 are connected together thereby to form a swash
plate chamber 33 therebetween. The swash plate chamber 33 is in
communication with the first recess 21C. Thus, the first recess 21C
forms a part of the swash plate chamber 33.
[0043] The second cylinder block 23 has therein a plurality of
second cylinder bores 23A that extends along the axis of rotation
O1 of the drive shaft 3 and has the same diameter as the first
cylinder bores 21A formed in the first cylinder block 21. As with
case of the first cylinder bores 21A, the second cylinder bores 23A
are spaced angularly at a regular interval around the drive shaft 3
in the second cylinder block 23. Each second cylinder bore 23A is
paired with its corresponding first cylinder bore 21A. Any number
of the first and second cylinder bores 21A, 23A may be formed in
the housing as long as the first and the second cylinder bores 21A,
23A are provided in pairs.
[0044] The second cylinder block 23 has therein a second shaft hole
23B through which the drive shaft 3 is inserted. A second slide
bearing 22B is provided in the second shaft hole 23B. It is to be
noted that the first and second slide bearings 22A, 22B may be
replaced with rolling bearings.
[0045] In addition, the second cylinder block 23 has at the center
thereof a second recess 23C that is formed coaxially with the
second shaft hole 23B and communicates with the second shaft hole
23B. The second recess 23C has an inner diameter that is larger
than that of the second shaft hole 23B. A second thrust bearing 35B
is provided in the second recess 23C.
[0046] The second cylinder block 23 has a discharge port 23D, a
junction 23J, a suction port 23S, a third front passage 18C, a
second rear passage 20B, and a second connecting passage 37B. The
discharge port 23D and the junction 23J communicate with each
other. The junction 23J is connected through the discharge port 23D
to a condenser (not shown) that forms the refrigeration circuit of
the vehicle air conditioner. The suction port 23S and the swash
plate chamber 33 are in communication with each other. The swash
plate chamber 33 is connected to an evaporator (not shown) that
forms the refrigeration circuit of the vehicle air conditioner
through the suction port 23S.
[0047] The third front passage 18C is in communication at the rear
end thereof with the junction 23J and is opened at the front end
thereof to the front end of the second cylinder block 23 to be in
communication with the second front passage 18B. The second rear
passage 20B is in communication at the front end thereof with the
junction 23J and is opened at the rear end thereof to the rear end
of the second cylinder block 23. The second connecting passage 37B
is opened at the front end thereof to the swash plate chamber 33
and at the rear end thereof to the rear end of the second cylinder
block 23.
[0048] The first housing member 17 and the first cylinder block 21
are joined together with the first valve-forming plate 39
interposed therebetween. The second housing member 19 and the
second cylinder block 23 are joined together with the second
valve-forming plate 41 interposed therebetween.
[0049] The first valve-forming plate 39 includes a first valve
plate 390, a first suction valve plate 391, a first discharge valve
plate 392, and a first retainer plate 393. The first valve plate
390 and the first suction valve plate 391 extend radially to the
outer peripheries of the first housing member 17 and the first
cylinder block 21. The first valve plate 390, the first discharge
valve plate 392, and the first retainer plate 393 have therethrough
a first suction hole 390A for each of the first cylinder bores 21A.
The first valve plate 390 and the first suction valve plate 391
have therethrough a first discharge hole 390B for each of the first
cylinder bores 21A. In addition, the first valve plate 390, the
first suction valve plate 391, the first discharge valve plate 392,
and the first retainer plate 393 have therethrough a first suction
communication hole 390C. The first valve plate 390 and the first
suction valve plate 391 have therethrough a first discharge
communication hole 390D.
[0050] Each first cylinder bore 21A is communicable with the first
suction chamber 27A through the first suction hole 390A and is
communicable also with the first discharge chamber 29A through the
first discharge hole 390B. The first suction chamber 27A and the
first connecting passage 37A are in communication with each other
through the first suction communication hole 390C. The first front
passage 18A and the second front passage 18B are in communication
with each other through the first discharge communication hole
390D.
[0051] The first suction valve plate 391 is provided on the rear
surface of the first valve plate 390. The first suction valve plate
391 has a first suction reed valve 391A for each of the first
suction holes 390A to open and close its corresponding first
suction hole 390A by elastic deformation. The first discharge valve
plate 392 is provided on the front surface of the first valve plate
390. The first discharge valve plate 392 has a first discharge reed
valve 392A for each of the first discharge holes 390B to open and
close its corresponding first discharge hole 390B by elastic
deformation. The first retainer plate 393 is provided on the front
surface of the first discharge valve plate 392 and restricts the
opening of the first discharge reed valve 392A.
[0052] The second valve-forming plate 41 includes a second valve
plate 410, a second suction valve plate 411, a second discharge
valve plate 412, and a second retainer plate 413. The second valve
plate 410 and the second suction valve plate 411 extend radially to
the outer peripheries of the second housing member 19 and the
second cylinder block 23. The second valve plate 410, the second
discharge valve plate 412, and the second retainer plate 413 have
therethrough a second suction hole 410A for each of the second
cylinder bores 23A. The second valve plate 410 and the second
suction valve plate 411 have therethrough a second discharge hole
410B for each of the second cylinder bores 23A. In addition, the
second valve plate 410, the second suction valve plate 411, the
second discharge valve plate 412, and the second retainer plate 413
have therethrough a second suction communication hole 410C. The
second valve plate 410 and the second suction valve plate 411 have
therethrough a second discharge communication hole 410D.
[0053] Each second cylinder bore 23A is communicable with the
second suction chamber 27B through the second suction hole 410A and
is communicable also with the second discharge chamber 29B through
the second discharge hole 410B. The second suction chamber 27B and
the second connecting passage 37B are in communication with each
other through the second suction communication hole 410C. The first
rear passage 20A and the second rear passage 20B are in
communication with each other through the second discharge
communication hole 410D.
[0054] The second suction valve plate 411 is provided on the front
surface of the second valve plate 410. The second suction valve
plate 411 has a second suction reed valve 411A for each of the
second suction holes 410A to open and close its corresponding
second suction hole 410A by elastic deformation. The second
discharge valve plate 412 is provided on the rear surface of the
second valve plate 410. The second discharge valve plate 412 has a
second discharge reed valve 412A for each of the second discharge
holes 410B to open and close its corresponding second discharge
hole 410B by elastic deformation. The second retainer plate 413 is
provided on the rear surface of the second discharge valve plate
412 and restricts the opening of the second discharge reed valve
412A.
[0055] In the compressor, the first front passage 18A, the first
discharge communication hole 390D, the second front passage 18B,
and the third front passage 18C cooperate to form a first discharge
passage 18. The first rear passage 20A, the second discharge
communication hole 410D and the second rear passage 20B cooperate
to form a second discharge passage 20.
[0056] The first suction chamber 27A is in communication with the
swash plate chamber 33 through the first connecting passage 37A and
the first suction communication hole 390C, and the second suction
chamber 27B is in communication with the swash plate chamber 33 via
the second connecting passage 37B and the second suction
communication hole 410C, so that the pressures in the first and
second suction chambers 27A, 27B are substantially the same as
those in the swash plate chamber 33.
[0057] The drive shaft 3 includes a drive shaft body 30, a first
support member 43A and a second support member 43B.
[0058] The drive shaft body 30 extends along the axis of rotation
O1 in the housing 1. The drive shaft body 30 has at the front end
thereof a first small diameter portion 30A and at the rear end
thereof a second small diameter portion 30B.
[0059] The drive shaft body 30 is inserted through the shaft seal
device 25, the first and second slide bearings 22A, 22B in the
housing 1, so that the drive shaft body 30 and hence the drive
shaft 3 is supported rotatably about the axis of rotation O1 in the
housing 1. The front end of the drive shaft body 30 of the drive
shaft 3 is inserted through the shaft seal device 25 in the boss
17A and the rear end of the drive shaft body 30 of the drive shaft
3 extends into the pressure control chamber 31.
[0060] The drive shaft body 30 has mounted thereon the swash plate
5, the link mechanism 7, and the actuator 13 that are disposed in
the swash plate chamber 33.
[0061] The drive shaft body 30 has at the front end thereof a
threaded portion 3E. The drive shaft 3 is connected to a pulley or
an electromagnetic clutch (neither shown) through the threaded
portion 3E.
[0062] The first support member 43A has a substantially cylindrical
shape extending along the axis of rotation O1. The first support
member 43A is press-fitted on the first small diameter portion 30A
of the drive shaft body 30 to be integrated therewith. The first
support member 43A is supported by the first slide bearing 22A in
the first shaft hole 21B. The first support member 43A has at the
rear end thereof a first flange 43F and a mount portion 43D through
which a second pin 47B, which will be described later, is
inserted.
[0063] The first thrust bearing 35A is held between the first
flange 43F and the bottom surface of the first recess 21C in the
axial direction of the drive shaft 3, with a predetermined preload
applied to the first thrust bearing 35A. With this arrangement, a
thrust force acting on the drive shaft 3 during the operation of
the compressor is supported by the first thrust bearing 35A.
[0064] The second support member 43B has a substantially
cylindrical shape extending along the axis of rotation O1. The
second support member 43B is press-fitted on the second small
diameter portion 30B of the drive shaft body 30 to be integrated
therewith. The second support member 43B is supported by the second
slide bearing 22B in the second shaft hole 23B. The second support
member 43B has at the front end thereof a second flange 43G.
[0065] The second thrust bearing 35B is held between the second
flange 43G and the bottom surface of the second recess 23C in the
axial direction of the drive shaft 3 with a predetermined preload
applied to the second thrust bearing 35B. With this arrangement, a
thrust force acting on the drive shaft body 30 during the operation
of the compressor is supported by the second thrust bearing
35B.
[0066] As shown in FIGS. 1, 2, 4 through 7A and 7B, the swash plate
5 has a substantially disk shape having a front surface 5A and a
rear surface 5B. The swash plate 5 is disposed in the swash plate
chamber 33 with the front surface 5A and the rear surfaces 5B
thereof facing frontward and rearward of the compressor,
respectively. As shown in FIGS. 1 and 2 showing the swash plate 5
in its minimum and maximum positions, respectively, the swash plate
5 is tiltable with respect to a direction perpendicular to the axis
of rotation O1.
[0067] Referring to FIG. 7B, symbol T designates a top dead center
portion which is a point or portion in the swash plate 5 where the
swash plate 5 positions a first head portion 9A of the piston 9 at
the top dead center thereof, as shown in FIG. 1, and symbol U
designates a bottom dead center portion which is a point or portion
of the swash plate 5 where the swash plate 5 positions the first
head portion 9A of the piston 9 at the bottom dead center thereof,
respectively. Since the compressor of the present embodiment is of
a double-headed piston type, the swash plate 5 positions the second
head portion 9B of the piston 9 at the bottom dead center thereof
when the second head portion 9B is positioned at the top dead
center. Symbol D in FIG. 7B designates an imaginary plane that
passes through the point T of the swash plate 5 and the axis of
rotation O1 of the drive shaft 3.
[0068] As shown in FIGS. 1, 2, 6, 7A and 7B, the swash plate 5 has
a ring plate 45 having an annular shape. As shown in FIG. 7A, the
part of the swash plate 5 that is radially inward of the ring plate
45 is partially projected or recessed in a direction of the axis of
rotation O1 so as to adjust the weight balance of the swash plate 5
and to avoid the interference with a first arm 110 and a second arm
120, which will be described later.
[0069] As shown in FIGS. 7A and 7B, an insertion hole 45A is formed
through the swash plate 5 in the axial direction of the axis of
rotation O1. The insertion hole 45A has a substantially rectangular
shape formed so as to have therein the axis of rotation O1 and
extending toward the top dead center portion T. As shown in FIGS. 1
and 2, the swash plate 5 is mounted on the drive shaft 3 in the
swash plate chamber 33 with the drive shaft body 30 inserted
through the insertion hole 45A of the ring plate 45 of the swash
plate 5.
[0070] As shown in FIGS. 1, 2, and 4 to 7B, the swash plate 5 has a
traction portion 150 and a link pin 155 that form a connecting
mechanism 100. The connecting mechanism 100 connects the swash
plate 5 to a movable body 13A, which will be described later. As
shown in FIGS. 7A and 7B, the traction portion 150 is formed at a
position in the swash plate 5 radially inward of the ring plate 45
and is closer to the bottom dead center portion U than the
insertion hole 45A is, and projects rearward from the rear surface
5B of the swash plate 5. A pin hole 150H having the axis R1
extending perpendicular to the imaginary plane D is formed through
the traction portion 150. The link pin 155 is inserted through the
pin hole 150H.
[0071] As shown in FIGS. 6 and 7B, the link pin 155 is supported
rotatable about the axis R1 by the traction portion 150. The link
pin 155 has a shape of circular column extending radially from the
axis R1. According to the present embodiment, the link pin 155 is
made of a metal such as steel and aluminum alloy, but any suitable
material may be used for the link pin 155. The outer diameter of
the link pin 155 is formed just smaller than the inner diameter of
the pin hole 150H to such an extent that lubricant oil included in
a refrigerant gas forms an oil film between the outer peripheral
surface of the link pin 155 and the inner peripheral surface of the
pin hole 150H, which significantly reduces the friction between the
link pin 155 and the pin hole 150H during the rolling of the link
pin 155 about the axis R1.
[0072] The link pin 155 has at one end thereof a first shaft
portion 151 and at the other end thereof a second shaft portion
152. Part of the first shaft portion 151 extends out from the pin
hole 150H of the traction portion 150 on one side of the imaginary
plane D and part of the second shaft portion 152 extends out from
the pin hole 150H on the other side of the imaginary plane D.
[0073] As shown in FIGS. 4, 5, 7A and 7B, the swash plate 5 has a
pair of connecting portions 5G that connect the swash plate 5 and a
lug arm 49, which will be described later. As shown in FIGS. 7A and
7B, the connecting portions 5G are formed at positions in the swash
plate 5 that are radially outward of the insertion hole 45A of the
ring plate 45 of the swash plate 5 and adjacent to the top dead
center portion T. The connecting portions 5G project frontward from
the front surface 5A of the swash plate 5 and are disposed on
opposite sides of the insertion hole 45A across the imaginary plane
D, projecting frontward from the front surface 5A of the swash
plate 5. Each connecting portion 5G has therethrough a first pin
hole 5H extending perpendicularly to the imaginary plane D.
[0074] Referring to FIGS. 1 and 2, a return spring (not shown) is
provided between the first flange 43F and the ring plate 45.
Specifically, the return spring is mounted with the front end
thereof set in contact with the first flange 43F and at the rear
end thereof set in contact with the ring plate 45. The return
spring urges the first flange 43F and the ring plate 45 away from
each other.
[0075] As shown in FIGS. 1, 2, 4 and 5, the link mechanism 7
includes the aforementioned lug arm 49, a first pin 47A, and the
aforementioned second pin 47B.
[0076] Referring to FIGS. 1 and 2, the lug arm 49 is disposed
frontward of the swash plate 5 in the swash plate chamber 33 and
positioned between the swash plate 5 and the first support member
43A. The lug arm 49 has a substantially L-shape and has at the rear
end thereof a weight 49A.
[0077] The first pin 47A is inserted through the rear end of the
lug arm 49 with the opposite ends of the first pin 47A fixedly
fitted in the first pin holes 5H in the respective connecting
portions 5G, thus connecting the rear end of the lug arm 49 and the
swash plate 5. The lug arm 49 is supported swingably about a first
axis M1 that extends perpendicularly to the imaginary plane D and
corresponds to the axis of the first pin 47A.
[0078] The front end of the lug arm 49 is connected to the first
support member 43A by the second pin 47B. Thus, the lug arm 49 is
supported swingably about a second axis M2 that extends parallel to
the first axis M1 and corresponds to the axis of the second pin 47B
and relative to the first support member 43A or the drive shaft
3.
[0079] The weight 49A is provided forming a rear part of the lug
arm 49. Specifically, the weight 49A is located on the side of the
first axis M1 that is opposite from the second axis M2. With the
lug arm 49 connected to the swash plate 5 by the first pin 47A, the
weight 49A is positioned in the insertion hole 45A of the swash
plate 5. The centrifugal force caused by the rotation of the swash
plate 5 about the axis of rotation O1 acts on the weight 49A.
[0080] In the compressor of the present embodiment, the swash plate
5 is connected to the drive shaft 3 through the link mechanism 7,
so that the swash plate 5 is rotatable with the drive shaft 3. In
other words, the swash plate 5 is mounted on the drive shaft 3 for
rotation therewith in the swash plate chamber 33. With the swinging
movement of the opposite ends of the lug arm 49 about the first
axis M1 and the second axis M2, respectively, the inclination angle
of the swash plate 5 with respect to an imaginary plane extending
perpendicularly to the axis O1 is variable between the maximum
inclination angle shown in FIGS. 1 and 4 and the minimum
inclination angle shown in FIGS. 2, 5 and 6. In other words, the
link mechanism 7 connects the drive shaft 3 and the swash plate 5
and permits changing of the inclination angle of the swash plate 5
relative to the imaginary plane extending perpendicularly to the
axis of rotation O1 of the drive shaft 3.
[0081] As shown in FIGS. 1 and 2, the pistons 9 are double-headed
pistons each having at the front end thereof the first head portion
9A and at the rear end thereof the second head portion 9B. Each
first head portion 9A is reciprocally movably received in the
corresponding first cylinder bore 21A and a first compression
chamber 53A is defined by the first head portion 9A and the first
valve-forming plate 39 in each first cylinder bore 21A. In other
words, the first head portions 9A of the pistons 9 are received in
the respective first cylinder bores 21A so as to form the first
compression chambers 53A. Each second head portion 9B is
reciprocally movably received in the corresponding second cylinder
bore 23A and a second compression chamber 53B is defined by the
second head portion 9B and the second valve-forming plate 41 in
each second cylinder bore 23A. In other words, the second head
portions 9B of the pistons 9 are received in the respective second
cylinder bores 23A.
[0082] Each piston 9 has at the center thereof an engaging portion
9C to receive therein a pair of hemispherical shoes 11A, 11B. The
shoe 11A and the shoe 11B slide on the front surface 5A and the
rear surface 5B of the swash plate 5, respectively. The rotation of
the swash plate 5 is converted into the reciprocal motion of the
piston 9 by way of the shoes 11A, 11B. Thus, the first head portion
9A and the second head portion 9B of the piston 9 are reciprocally
movable by the rotation of the swash plate 5 in their corresponding
first cylinder bore 21A and the second cylinder bore 23A,
respectively, for a stroke length that is determined by the
inclination angle of the swash plate 5.
[0083] In this compressor, the positions of the top dead center of
the first head portion 9A and the second head portion 9B are
variable with the change of the stroke length that is caused by the
change of the inclination angle of the swash plate 5. Specifically,
the top dead center of the second head portion 9B moves a longer
distance than the first head portion 9A does as the inclination
angle of the swash plate 5 is reduced.
[0084] The actuator 13 is disposed rearward of the swash plate 5 in
the swash plate chamber 33 and movable into and out of the second
recess 23C. The actuator 13 includes a partitioning body 130 and
the aforementioned movable body 13A and a control chamber 13B that
is formed between the partitioning body 13C and the movable body
13A. In the present embodiment, the partitioning body 13C and the
movable body 13A are made of a metal such as a steel and an
aluminum alloy. It is to be noted that the partitioning body 13C
and the movable body 13A need not be made of a metal, but any
suitable material may be used for the partitioning body 13C and the
movable body 13A.
[0085] The partitioning body 13C has a substantially annular disk
shape extending radially outwardly from the axis of rotation O1 and
has at the center thereof an insertion hole 133. An O-ring 139B is
provided in the outer periphery of the partitioning body 13C. The
drive shaft body 30 is press-fitted into the insertion hole 133 of
the partitioning body 13C, so that the drive shaft body 30 is
rotatable with the partitioning body 13C facing the swash plate 5
from behind thereof. It is to be noted that the partitioning body
13C may be mounted on the drive shaft body 30 so as to be movable
along the axis of rotation O1.
[0086] A spring (not shown) is provided between the partitioning
body 13C and the ring plate 45, acting so as to reduce the
inclination angle of the swash plate 5. Specifically, the spring is
mounted with the rear end thereof set in contact with the
partitioning body 13C and the front end thereof set in contact with
the ring plate 45. The spring urges the partitioning body 13C and
the ring plate 45 away from each other.
[0087] As shown in FIGS. 1, 2, 4 to 6, and 8 to 12, the movable
body 13A includes a bottom wall 130, a peripheral wall 131, the
first arm 110, and the second arm 120. Although the first arm 110
is not shown in FIGS. 1, 2, and 10B, the first arm 110 is disposed
on the side of the imaginary plane D that is opposite to the second
arm 120.
[0088] As shown in FIGS. 1, 2, 6 and 9, the bottom wall 130 forms
the rear part of the movable body 13A and has a substantially disk
shape extending radially outwardly. The bottom wall 130 has an
insertion hole 130A through which the second small diameter portion
30B of the drive shaft body 30 is inserted. As shown in FIGS. 1 and
2, an O-ring 139A is provided in the inner periphery of the bottom
wall 130.
[0089] As shown in FIGS. 1, 2, 8 and 9, the peripheral wall 131 of
the movable body 13A has a cylindrical shape extending frontward
from the outer periphery of the bottom wall 130. The inner diameter
of the peripheral wall 131 is formed slightly larger than the outer
diameter of the partitioning body 13C.
[0090] As shown in FIGS. 1, 2 and 6, the drive shaft body 30 is
inserted through the insertion hole 130A of the movable body 13A.
Thus, the movable body 13A is mounted on the drive shaft body 30
for rotation therewith and movable relative to the partitioning
body 13C along the axis of rotation O1.
[0091] As shown in FIGS. 1 and 2, the partitioning body 13C is
disposed in the movable body 13A in such a manner that the movable
body 13A is circumferentially surrounded by the peripheral wall 131
of the movable body 13A. The O-ring 139B is provided in the outer
periphery of the partitioning body 13C to seal between the
partitioning body 13C and the movable body 13A. As the movable body
13A moves along the axis of rotation O1, the inner peripheral
surface of the peripheral wall 131 of the movable body 13A slides
on the outer peripheral surface of the partitioning body 13C.
[0092] As shown in FIGS. 1, 2, 4 to 6 and 8 to 12, the first arm
110, the second arm 120, the traction portion 150 and the link pin
155 cooperate to form the connecting mechanism 100 that connects
the swash plate 5 and the movable body 13A.
[0093] The first and second arms 110, 120 extend frontward from the
movable body 13A toward the swash plate 5. As shown in FIGS. 9, 10A
and 12, the first arm 110 is disposed on one side of the imaginary
plane D that is adjacent to the first shaft portion 151 of the link
pin 155, and the second arm 120 is disposed on the other side of
the imaginary plane D that is adjacent to the second shaft portion
152 of the link pin 155. As shown in FIG. 6, the traction portion
150 extends rearward from the swash plate 5 toward the movable body
13A and between the first arm 110 and the second arm 120.
[0094] As, shown in FIGS. 8 to 12, the first arm 110 includes a
first facing portion 111 and a first engaging portion 116.
Similarly, the second arm 120 includes a second facing portion 121
and the second engaging portion 126.
[0095] The rear ends of the first and second facing portions 111,
121 are connected to the front end of the movable body 13A at
positions that are closer to the bottom dead center portion U than
to the axis of rotation O1. The distances from the front end of the
first and second facing portions 111, 121 to the axis of rotation
O1 is greater than those from the rear ends of the first and second
facing portions 111, 121.
[0096] As shown in FIGS. 8 through 12, the front ends of the first
and second arms 110, 120 are bent thereby to form the first and
second engaging portions 116, 126 extending toward the imaginary
plane D, respectively. Specifically, the first engaging portion 116
is formed extending from the front end of the first facing portion
111 and the second engaging portion 126 extending from the front
end of the second facing portion 121 toward the imaginary plane D.
As shown in FIGS. 9 and 12, the first engaging portion 116 and the
second engaging portion 126 are disposed in facing relation to each
other across the imaginary plane D.
[0097] As shown in FIGS. 8 through 12, the first engaging portion
116 of the first arm 110 has a flat first guide surface 115 facing
away from the swash plate 5. The second engaging portion 126 of the
second arm 120 has a flat second guide surface 125 facing away from
the swash plate 5. The first and second guide surfaces 115, 125 are
tilted so that distances from the first and second guide surfaces
115, 125 to the axis of rotation O1 increase toward the rear of the
compressor.
[0098] As shown in FIGS. 1, 2, 4 through 6, 11 and 12, the first
guide surface 115 of the first arm 110 is in contact with the first
shaft portion 151 of the link pin 155, and the second guide surface
125 of the second arm 120 is in contact with the second shaft
portion 152 of the link pin 155, respectively With the link pin 155
held by the traction portion 150 rotatably about the axis R1, the
link pin 155 is rollable on the first and second guide surfaces
115, 125.
[0099] As shown, for example, in FIGS. 6 and 12, the first facing
portion 111 of the first arm 110 faces an end surface 151E of the
first shaft portion 151 of the link pin 155 on one side of the
imaginary plane D, and the second facing portion 121 of the second
arm 120 faces an end surface 152E of the second shaft portion 152
of the link pin 155 on the other side of the imaginary plane D,
respectively. Peripheries of the end surfaces 151E, 152E of the
respective first and second shaft portions 151, 152 are
chamfered.
[0100] The first and second facing portions 111, 122 are disposed
facing the first and second shaft portions 151, 152 of the link pin
155, respectively, so that the movement of the link pin 155 in
axial direction of the axis R1 is restricted. The first and second
facing portions 111, 112 correspond to the restrictor of the
present invention.
[0101] With a change in the inclination angle of the swash plate 5,
the first and second shaft portions 151, 152 of the link pin 155
are movable in a reciprocating manner while rolling on the first
guide surface 115 of the first arm 110 and the second guide surface
125 of the second arm 120, respectively. Referring to FIG. 11, for
example, D1 designates a direction in which the link pin 155 moves
on the first and second guide surfaces 115, 125 with an increase of
the inclination angle of the swash plate 5 is increased. The moving
direction D1 is directed frontward and inclined toward the axis of
rotation O1.
[0102] As shown in FIGS. 6, 8 through 11, the first and second arms
110, 120 are opened on the side thereof that is upstream with
respect to the moving direction D1 through which the first and
second shaft portions 151, 152 may be passed to be inserted into
the corresponding first and second arms 110, 120.
[0103] The following will describe the assembling procedure of the
swash plate 5 and the movable body 13A through the connecting
mechanism 100. Firstly, the first support member 43A of the drive
shaft 3 and the front end of the lug arm 49 are connected together
by the second pin 47B, as shown in FIG. 13.
[0104] Then, the second small diameter portion 30B of the drive
shaft body 30 before being press-fitted into the second support
member 43B is inserted through the insertion hole 45A of the swash
plate 5. The swash plate 5 thus having the drive shaft 3 inserted
through the insertion hole 45A thereof is brought close to the lug
arm 49 and the weight 49A of the lug arm 49 is inserted through the
insertion hole 45A of the swash plate 5. At this time, the traction
portion 150 of the swash plate 5 is located radially outward of and
eccentric to the axis of rotation O1 of the drive shaft 3.
[0105] Subsequently, the partitioning body 13C and the movable body
13A of the actuator 13 are assembled on the drive shaft body 30
from the second small diameter portion 30B side, and the movable
body 13A is moved frontward toward the swash plate 5. Then, the
link pin 155 is inserted through the pin hole 150H of the traction
portion 150. The position of the swash plate 5 is adjusted so that
the first and second shaft portions 151, 152 of the link pin 155
are located radially outward of the first and second guide surfaces
115, 125, respectively.
[0106] The swash plate 5 is moved in the moving direction D1 so
that the first and second shaft portions 151, 152 of the link pin
155 held by the traction portion 150 are placed in contact with the
corresponding first and second guide surfaces 115, 125 of the first
and second arms 110, 120, respectively. After the first pin 47A is
inserted through the rear end of the lug arm 49, the opposite ends
of the first pin 47A are fixedly fitted to the first pin holes 5H
of the connecting portions 5G, respectively. Accordingly, the swash
plate 5 and the movable body 13A are connected together via the
connecting mechanism 100. The first and second facing portions 111,
121 prevent the link pin 155 from being displaced in the axial
direction of the axis R1.
[0107] As shown in FIGS. 1 and 2, the control chamber 13B that is
defined by the bottom wall 130 and the peripheral wall 131 of the
movable body 13A and the partitioning body 13C is formed in the
swash plate chamber 33.
[0108] The second small diameter portion 30B of the drive shaft
body 30 has therein an axial passage 3A that extends frontward from
the rear end of the drive shaft body 30 along the axis of rotation
O and a radial passage 3B that extends radially from the front end
of the axial passage 3A and is opened at the outer peripheral
surface of the drive shaft body 30. The axial passage 3A is in
communication through the rear end thereof with the pressure
control chamber 31 and the radial passage 3B is in communication
with the control chamber 13B. Thus, the control chamber 13B and the
pressure control chamber 31 communicate with each other through the
radial passage 3B and the axial passage 3A.
[0109] As shown in FIG. 3, the control mechanism 15 includes a
low-pressure passage 15A, a high-pressure passage 15B, a control
valve 15C, an orifice 15D, the axial passage 3A and the radial
passage 3B. The control mechanism 15 controls the pressure in the
control chamber 13B.
[0110] The low-pressure passage 15A is connected to the pressure
control chamber 31 and the second suction chamber 27B. The control
chamber 13B, the pressure control chamber 31 and the second suction
chamber 27B are connected through the low-pressure passage 15A, the
axial passage 3A and the radial passage 3B. The high-pressure
passage 15B is connected between the pressure control chamber 31
and the second discharge chamber 29B. The control chamber 13B, the
pressure control chamber 31 and the second discharge chamber 29B
are connected through the high-pressure passage 15B, the axial
passage 3A and the radial passage 3B. The high-pressure passage 15B
is provided with the orifice 15D.
[0111] The control valve 15C is provided in the low-pressure
passage 15A. The control valve 15C controls the opening of the
low-pressure passage 15A according to the internal pressure of the
second suction chamber 27B.
[0112] The compressor of the present embodiment is connected with
the aforementioned evaporator (not shown) through a pipe (not
shown) connected to the suction port 23S. The compressor is also
connected to the aforementioned condenser (not shown) by a pipe
(not shown) through the discharge port 23D. The condenser is
connected to the evaporator through the pipe and an expansion valve
(neither shown). The compressor, the evaporator, the expansion
valve and the condenser cooperate to form a refrigeration circuit
of the vehicle air conditioner. The evaporator, the expansion
valve, the condenser and the pipes are omitted from the
illustration in the drawings.
[0113] In the compressor having the above-described configuration,
the rotation of the swash plate 5 driven by the drive shaft 3
causes each piston 9 to reciprocate in the respective first and
second cylinder bores 21A, 23A. The refrigerant gas introduced into
the first and second suction chambers 27A, 27B is compressed in the
first and second compression chambers 53A, 53B, respectively, and
the compressed refrigerant gas is discharged to their corresponding
first and second discharge chambers 29A, 29B. The displacement of
the pistons and hence the delivery of compressed refrigerant gas
from the first and second compression chambers 53A, 53B are varied
according to the stroke length of the piston 9.
[0114] The refrigerant gas discharged into the first discharge
chamber 29A is flowed through the first discharge passage 18 to the
junction 23J. Similarly, the refrigerant gas discharged into the
second discharge chamber 29B is flowed through the second discharge
passage 20 to the junction 23J. The refrigerant gas flowed to the
junction 23J is discharged through the discharge port 23D to the
condenser through the pipe.
[0115] The following will describe the operation of the compressor.
In the compressor of the present embodiment, the inclination angle
of the swash plate 5 relative to the imaginary plane extending
perpendicularly to the axis of rotation O1 of the drive shaft 3 is
changed by the actuator 13, which increases or decreases the stroke
length of the piston 9 and hence changes the displacement of the
compressor.
[0116] Firstly, the operation of the compressor in increasing the
inclination angle of the swash plate 5 to its maximum position
shown in FIG. 1 will be described. In the control mechanism 15
shown in FIG. 3, when the opening of the low-pressure passage 15A
is reduced by the control valve 15C, the pressure in the pressure
control chamber 31 is increased due to the pressure of the
refrigerant gas in the second discharge chamber 29B, and the
pressure in the control chamber 13B is increased accordingly. As a
result, the variable pressure difference between the control
chamber 13B and the swash plate chamber 33 is increased.
Accordingly, the movable body 13A of the actuator 13 is moved
rearward from the position shown in FIG. 2 against the compression
reaction force acting on the swash plate 5 through each piston 9
and enters into the second recess 23C, as shown in FIG. 1.
[0117] This causes the movable body 13A to pull the swash plate 5
rearward in the swash plate chamber 33 through the first and second
guide surfaces 115, 125 of the first and second arms 110, 120,
respectively, and the first and second shaft portions 151, 152 of
the link pin 155, against the urging force of the spring (not
shown) for reducing the inclination angle of the swash plate 5. In
this case, the first and second shaft portions 151, 152 roll on the
first and second guide surfaces 115, 125, respectively, toward the
axis of rotation O1. The swash plate 5 swings counterclockwise
about the first axis M1 as seen in FIGS. 1 and 2, and the front end
of the lug arm 49 swings clockwise about the second axis M2 to move
away from the first flange 43F of the first support member 43A. As
a result, the inclination angle of the swash plate 5 is increased
thereby to increase the stroke length of the piston 9, and the
displacement of the compressor per rotation of the drive shaft 3 is
increased. When the inclination angle of the swash plate 5 is
maximum, as shown in FIG. 1, the stroke of the pistons 9 is maximum
and the displacement of the compressor is maximum.
[0118] The operation of the compressor in decreasing the
inclination angle of the swash plate 5 from the maximum position
(FIG. 1) to the minimum position (FIG. 2) will be described. In the
control mechanism 15 in FIG. 3, when the opening of the
low-pressure passage 15A is increased by the control valve 15C, the
pressure in the pressure control chamber 31 and hence the pressure
in the control chamber 13B becomes substantially the same as the
pressure in the second suction chamber 27B, with the result that
the pressure difference between the control chamber 13B and the
swash plate chamber 33 becomes small.
[0119] The compression reaction force acting on the swash plate 5
through each piston 9 urges the swash plate 5 in the direction that
reduces the inclination angle of the swash plate 5. Accordingly,
the movable body 13A is pulled or moved frontward in the swash
plate chamber 33 through the first and second guide surfaces 115,
125 of the first and second arms 110, 120 and the first and second
shaft portions 151, 152 of the link pin 155, resisting the urging
force of the return spring. During such movement of the movable
body 13A, the first and second shaft portions 151, 152 of the link
pin 155 move away from the axis of rotation O1 while rolling on the
first and second guide surfaces 115, 125 of the first and second
arms 110, 120, as shown in FIG. 11. As a result, the swash plate 5
is swung clockwise about the axis M1. In addition, the lug arm 49
is swung counterclockwise about the second axis M2, thus moving the
front end of the lug arm 49 close to the first flange 43F of the
first support member 43A, with the result that the inclination
angle of the swash plate 5 is reduced. With the reduction of the
inclination angle of the swash plate 5, the stroke length of the
piston 9 is decreased and the discharge volume per rotation of the
drive shaft 3 is decreased accordingly. When the inclination angle
of the swash plate 5 is minimum, the stroke length of the piston 9
is minimum and the discharge volume per rotation of the drive shaft
3 becomes minimum accordingly. In other words, the movable body 13A
of the actuator 13 is movable along the axis of rotation O1 so as
to change the inclination angle of the swash plate 5 and in
response to a change of pressure in the control chamber 136 of the
actuator 13.
[0120] According to the compressor of the first embodiment, the
link pin 155 is held rotatable about the axis R1 by the traction
portion 150, as shown in FIGS. 7B, 11 and 12, with the film of
lubrication oil which is contained in the refrigerant gas formed
between the outer peripheral surface of the link pin 155 and the
inner peripheral surface of the pin hole 150H. The first shaft
portion 151 of the link pin 155 is in contact with the first guide
surface 115 on the side thereof that is opposite from the swash
plate 5 and the second shaft portion 152 of the link pin 155 is in
contact with the second guide surface 125 on the side thereof that
is opposite from the swash plate 5. The first and second facing
portions 111, 121 functioning as the restrictors face the
corresponding end surfaces 151E, 152E of the link pin 155 so as to
prevent the displacement of the link pin 155 in axial direction of
the axis R1. In the compressor having this configuration, the first
and second shaft portions 151, 152 are movable in a reciprocating
manner and rollable on the first and second guide surfaces 115,
125, respectively. The rolling motion of the first and second shaft
portions 151, 152 of the link pin 155 on the first and second guide
surfaces 115, 152 reduces the friction therebetween effectively
and, as compared with the case in which the link pin 155 is fixed
to the traction portion 150 and the first and second shaft portions
151, 152 slide on the first and second guide surfaces 115, 125, the
friction becomes smaller.
[0121] In addition, the end surfaces 151E, 152E of the first and
second shaft portions 151, 152 are chamfered. Thus, the end
surfaces 151E, 152E of the first and second shaft portions 151, 152
permits smooth sliding contact of the first and second shaft
portions 151, 152 with the first and second facing portions 111,
121, which allows the first and second shaft portions 151, 152 to
rotate smoothly on the first and second guide surfaces 115,
125.
[0122] Therefore, the compressor of the first embodiment permits
smooth changing of the inclination angle of the swash plate 5. In
addition, the compressor provides the improved durability because
the first and second shaft portions 151, 152 and the first and
second guide surfaces 115, 125 are protected against friction
wear.
[0123] In the compressor of the present embodiment, the first and
second facing portions 111, 121 of the first and second arms 110,
120 that prevent the displacement of the link pin 155 in the axial
direction of the axis R1, so that the production cost may be
reduced because no additional parts needs to be used.
[0124] The following will describe a second embodiment of the
present invention with reference to FIGS. 14 and 15. The second
embodiment differs from the first embodiment in that the movable
body 13A includes a first arm 210 and a second arm 220, which are
shown in FIGS. 14 and 15, in place of the first and second arms
110, 120 of the first embodiment. In addition, in the second
embodiment, a pair of circlips 159 functioning as the restrictor is
mounted on the first and second shaft portions 151, 152 of the link
pin 155. The circlips 159 are disposed adjacently to the opposite
side surfaces of the traction portion 150. The rest of the
configuration of the compressor according to the second embodiment
is substantially the same as the first embodiment and, therefore,
further detailed description of the second embodiment will be
omitted. In the description below, like reference numerals will be
used to designate like parts or elements of the first
embodiment.
[0125] As shown in FIG. 14, the first and second arms 220 extend
frontward toward the swash plate 5 from the movable body 13A.
Although not shown in FIG. 14, the first arm 210 is disposed on the
side of the movable body 13A opposite from the imaginary plane
D.
[0126] As shown in FIG. 15, the first arm 210 and the second arm
220 are disposed on one side and other side of the imaginary plane
D, or the sides on which the first shaft portion 151 and the second
shaft portion 152 of the link pin 155 are disposed. The traction
portion 150 extends rearward from the swash plate 5 toward the
movable body 13A between the first and second arms 210, 220.
[0127] As shown in FIGS. 14 and 15, elongated holes 210H, 220H are
formed through the ends of the first and second arms 210, 220,
respectively, extending perpendicularly to the imaginary plane D.
As shown in FIG. 14, the elongated holes 210H and 220H are
elongated in the moving direction D1.
[0128] Referring to FIGS. 14 and 15, the first and second arms 210,
220 have flat first and second guide surfaces 215, 225 on the inner
surface of the elongated holes 210H, 220H, respectively, facing
away from the swash plate 5 and extending in the moving direction
D1.
[0129] The first guide surface 215 of the first arm 210 is in
contact with the first shaft portion 151 of the link pin 155 and
the second guide surface 225 of the second arm 220 is in contact
with the second shaft portion 152 of the link pin 155.
[0130] In the compressor of the second embodiment having such
configuration, with the changing of the inclination angle of the
swash plate 5, the first and second shaft portions 151, 152 are
reciprocally movable while rolling on the first and second guide
surfaces 215, 216, respectively.
[0131] Accordingly, the compressor of the second embodiment permits
smooth changing the inclination angle of the swash plate 5,
similarly to the compressor of the first embodiment. In addition,
the compressor of the second embodiment achieves improved
durability because the first and second shaft portions 151, 152 and
the first and second guide surfaces 215, 225 are protected against
friction wear.
[0132] The following will describe a third embodiment of the
present invention with reference to FIGS. 16 and 17. The compressor
of the third embodiment has a pin hole 350H in which the link pin
155 is rotatably supported in the traction portion 150 instead of
the pin hole 150H according to the compressor of the first
embodiment. In addition, the first and second shaft portions 151,
152 of the link pin 155 of the compressor according to the third
embodiment have spherical end surfaces 151E and 152E, respectively.
The rest of the configuration of the compressor according to the
third embodiment is substantially the same as the first embodiment
and, therefore, the description thereof will be omitted. In the
description below, like reference numerals will be used to
designate like parts or elements of the first embodiment.
[0133] In the compressor of the third embodiment, the pin hole 350H
has a generally hourglass shape with a diameter that is increased
axially outward from the middle toward the opposite ends, as shown
in FIGS. 16 and 17. Lubrication oil contained in the refrigerant
gas forms an oil film between the outer peripheral surface of the
link pin 155 and the inner peripheral surface of the pin hole 350H
at the middle portion thereof. The link pin 155 is rotatably
supported in the pin hole 350H. The pin hole 350H corresponds to
the support hole of the present invention. Specifically, the
traction portion 150 of the swash plate 5 supports the link pin 155
rotatably about the axis R1 while permitting the link pin 155 to be
tilted with respect to the direction extending perpendicularly to
the imaginary plane D, as indicated by two dashed-dotted lines in
FIG. 17.
[0134] In the compressor of the third embodiment having such
configuration, the first and second shaft portions 151, 152 are
reciprocally movable while rolling on the first and second guide
surfaces 115, 125, respectively. Though shown in FIG. 17 in an
exaggerated manner, when the swash plate 5 is disposed in twisted
state, or misaligned with respect to the to the axis of rotation
O1, the relative position between the first and second arms 110,
120 and the traction portion 150 fails to be maintained. In the
third embodiment, however, the first and second shaft portions 151,
152 of the link pin 155 and the first and second guide surfaces
115, 125 are kept in contact by causing the axis R1 of the link pin
155 to be inclined with respect to the direction perpendicular to
the imaginary plane D, so that the pulling force is applied
generally evenly to the first and second arms 110, 120.
[0135] In the third embodiment in which the end surfaces 151E, 152E
of the first and second shaft portions 151, 152 have a
hemispherical shape, the end surfaces 151E, 152E of the first and
second shaft portions 151, 152 may slide smoothly in contact with
the first and second facing portions 111, 121, which allows the
first and second shaft portions 151, 152 to roll smoothly on the
first and second guide surfaces 115, 125.
[0136] Accordingly, the compressor of the third embodiment permits
smooth changing of the inclination angle of the swash plate 5. In
addition, the compressor of the third embodiment achieves improved
durability because the first and second shaft portions 151, 152 and
the first and second guide surfaces 115, 125 are protected against
friction wear.
[0137] The present invention is not limited to the above described
first, second and third embodiments, but it may be modified in
various manners within the scope of the invention, as exemplified
below.
[0138] The restrictor is not limited to the first and second facing
portions 111, 121 of the first and second arms 110, 120 of the
first embodiment and the two circlips 159 of the second embodiment,
but any restrictor may be used as long as the displacement of the
link pin 155 in axial direction thereof is prevented.
[0139] Although the end surfaces 151E, 152E of the first and second
shaft portions 151, 152 in the first embodiment are chamfered and
the end surfaces 151E, 152E of the first and second shaft portions
151, 152 in the third embodiment have a hemispherical shape, the
end surfaces of the link pin may have a rounded edge.
[0140] The actuator 13 may be disposed on the first cylinder block
21 side in the swash plate chamber 33 with respect to the swash
plate 5.
[0141] The present invention is applicable to an air conditioner or
the like.
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