U.S. patent application number 16/461501 was filed with the patent office on 2019-10-31 for 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 Hidetaka HAYASHI, Tetsuya MITSUOKA, Shino OKUBO.
Application Number | 20190331105 16/461501 |
Document ID | / |
Family ID | 62145389 |
Filed Date | 2019-10-31 |
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United States Patent
Application |
20190331105 |
Kind Code |
A1 |
MITSUOKA; Tetsuya ; et
al. |
October 31, 2019 |
SWASH PLATE COMPRESSOR
Abstract
A swash plate compressor according to the present invention
includes a first slide layer formed between a swash plate and
shoes; and a second slide layer formed between cylinder bores and
pistons. The first slide layer and the second slide layer each
contain binder resin and solid lubricant. The first slide layer has
a smaller contact angle of lubricating oil than the second slide
layer.
Inventors: |
MITSUOKA; Tetsuya;
(Aichi-ken, JP) ; HAYASHI; Hidetaka; (Aichi-ken,
JP) ; OKUBO; Shino; (Aichi-ken, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KABUSHIKI KAISHA TOYOTA JIDOSHOKKI |
Aichi-ken |
|
JP |
|
|
Assignee: |
KABUSHIKI KAISHA TOYOTA
JIDOSHOKKI
Aichi-ken
JP
|
Family ID: |
62145389 |
Appl. No.: |
16/461501 |
Filed: |
October 20, 2017 |
PCT Filed: |
October 20, 2017 |
PCT NO: |
PCT/JP2017/037935 |
371 Date: |
May 16, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04B 49/12 20130101;
F04B 27/0886 20130101; F04B 27/12 20130101; F04B 27/0882 20130101;
F04B 39/00 20130101; F04B 27/10 20130101; F04B 27/1072 20130101;
F04B 27/109 20130101; F04B 27/18 20130101; F04B 39/0292 20130101;
F04B 39/02 20130101 |
International
Class: |
F04B 39/02 20060101
F04B039/02; F04B 27/12 20060101 F04B027/12; F04B 27/18 20060101
F04B027/18; F04B 49/12 20060101 F04B049/12 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 17, 2016 |
JP |
2016-223937 |
Claims
1.-4. (canceled)
5. A swash plate compressor comprising: a housing that includes a
swash-plate chamber and a plurality of cylinder bores; a drive
shaft that is supported by the housing and is rotatable within the
swash-plate chamber; a swash plate that is disposed within the
swash-plate chamber and is synchronously rotatable with the drive
shaft; shoes that slide on the swash plate; a piston that is
allowed by the shoes to make strokes that depend on an inclination
angle of the swash plate to reciprocate within the corresponding
cylinder bore to compress refrigerant that contains lubricating
oil; a first slide layer formed between the swash plate and the
shoes; and a second slide layer formed between the cylinder bores
and the piston, wherein the first slide layer and the second slide
layer each contain binder resin and solid lubricant, the solid
lubricant of the first slide layer contains ultra high molecular
weight polyethylene, and the solid lubricant of the second slide
layer contains fluorine resin, and the first slide layer has a
smaller contact angle of the lubricating oil than the second slide
layer.
6. The swash plate compressor according to claim 5, wherein the
swash-plate chamber directly communicates with an evaporator.
7. The swash plate compressor according to claim 6, further
comprising: a linkage that is disposed within the swash-plate
chamber and allows a change in the inclination angle of the swash
plate; and an actuator that is disposed within the swash-plate
chamber and changes the inclination angle of the swash plate,
wherein the actuator includes: a partition body that is rotatable
with the drive shaft within the swash-plate chamber; a movable body
that is rotatable with the drive shaft within the swash-plate
chamber and moves with respect to the partition body in an axis
direction of the drive shaft to change the inclination angle; a
control pressure chamber that is defined by the partition body and
the movable body and has a pressure within the control pressure
chamber that moves the movable body; and a control mechanism that
controls the pressure within the control pressure chamber.
Description
TECHNICAL FIELD
[0001] The present invention relates to a swash plate
compressor.
BACKGROUND ART
[0002] A general swash plate compressor includes a housing, a drive
shaft, a swash plate, a plurality pairs of shoes, and a plurality
of pistons. The housing includes a swash-plate chamber and a
plurality of cylinder bores. The drive shaft is supported by the
housing and is rotatable within the swash-plate chamber. The swash
plate is disposed within the swash-plate chamber and is
synchronously rotatable with the drive shaft. Each pair of shoes
slides on the swash plate. The pairs of shoes allow the respective
pistons to make strokes that depend on an inclination angle of the
swash plate to reciprocate within the respective cylinder bores.
First slide layers are formed on both surfaces of the swash plate
on which the shoes slide. Second slide layers are formed on outer
peripheral surfaces of the pistons that slide on the respective
cylinder bores.
[0003] Patent Document 1 discloses resin materials that may be used
for the first and second slide layers. The resin materials contain
fluorine resins such as polytetrafluoroethylene (PTFE), and ultra
high molecular weight polyethylene, for example. It is thought
that, in the swash plate compressor, the first slide layer allows
the shoes to appropriately slide on the swash plate, and the second
slide layer allows the pistons to appropriately slide in the
cylinder bores.
CITATION LIST
Patent Document
[0004] Patent Document 1: Japanese Patent Application Publication
No. 2010-60262
SUMMARY OF INVENTION
Technical Problem
[0005] However, if a swash plate compressor, an evaporator, a
condenser, and the like constitute a vehicle refrigeration circuit,
and the refrigeration circuit is filled with refrigerant and
lubricating oil and operates; much lubricating oil exists in some
portions of a swash-plate chamber and little lubricating oil exists
in other portions of the swash-plate chamber, according to
knowledge of the present inventors. Lubricating oil is less likely
to exist especially between a swash plate and shoes, and is likely
to exist especially between cylinder bores and pistons. On the
other hand, much lubricating oil is desirable between the swash
plate and the shoes, according to knowledge of the present
inventors.
[0006] In this regard, if a first slide layer is made of the
conventional resin materials described above, some selections of
the resin materials may cause wear or seizure between a swash plate
and shoes and thus deteriorate durability.
[0007] The present invention has been made in view of the
conventional circumstances described above. An object of the
present invention is to provide a swash plate compressor that has
excellent durability.
Solution to Problem
[0008] A swash plate compressor according to the present invention
includes: a housing that includes a swash-plate chamber and a
plurality of cylinder bores; a drive shaft that is supported by the
housing and is rotatable within the swash-plate chamber; a swash
plate that is disposed within the swash-plate chamber and is
synchronously rotatable with the drive shaft; shoes that slide on
the swash plate; a piston that is allowed by the shoes to make
strokes that depend on an inclination angle of the swash plate to
reciprocate within the corresponding cylinder bore to compress
refrigerant that contains lubricating oil;
[0009] a first slide layer formed between the swash plate and the
shoes; and a second slide layer formed between the cylinder bores
and the piston, and
[0010] the first slide layer and the second slide layer each
contain binder resin and solid lubricant, and
[0011] the first slide layer has a smaller contact angle of the
lubricating oil than the second slide layer.
[0012] As shown in results of an experiment by the present
inventors, the first slide layer that contains the binder resin and
the solid lubricant allows the shoes to appropriately slide on the
swash plate in the swash plate compressor according to the present
invention. Further, the second slide layer that contains the binder
resin and the solid lubricant allows the piston to appropriately
slide in the cylinder bores.
[0013] Especially in the swash plate compressor, the first slide
layer has a smaller contact angle of the lubricating oil than the
second slide layer. Therefore, the first slide layer has higher oil
wettability than the second slide layer. Therefore, much
lubricating oil is allowed to exist even between the swash plate
and the shoes where lubricating oil is less likely to exist due to
the structure of the swash plate compressor but much lubricating
oil is desirable. Therefore; wear or seizure is less likely to
occur between the swash plate and the shoes.
[0014] Further, much lubricating oil is not allowed to exist
between the cylinder bores and the pistons where lubricating oil is
likely to exist due to the structure of the swash plate compressor
but much lubricating oil is not desirable. That is, lubricating oil
is allowed to move to the swash-plate chamber through between the
cylinder bores and the pistons so that the lubricating oil exists
between the swash plate and the shoes.
[0015] Therefore; the swash plate compressor according to the
present invention has excellent durability.
[0016] The first and second slide layers each contain the binder
resin and the solid lubricant. The binder resin has a holding
property that holds the solid lubricant to decrease separation of
the solid lubricant, durability against shear force that repeatedly
acts under layers of films (hardness as a base), wear resistance
against breakage, and heat resistance, for example. For example,
polyimide-imide (PAI), polyimide, epoxy resin, or phenolic resin
may be used as the binder resin. Taking cost and properties into
consideration, PAI is optimum for the binder resin.
[0017] The solid lubricant is held by the binder resin, and has a
low shear force and a low coefficient of friction at an outermost
surface. For example, fluorine resin, molybdenum dioxide, graphite,
and ultra-high-molecular-weight-polyethylene particles may be used
as the solid lubricant. Fluorine resin and
ultra-high-molecular-weight-polyethylene particles each improve a
slippery property by forming a film on slide surfaces of the first
and second slide layers and being transferred to an opposite
material. Molybdenum dioxide and graphite each improve a slippery
property by a crystal structure that has a low shear force, and
provide less wear under high loads. According to results of an
experiment by the present inventors, fluorine resin has a sliding
property, such as wear resistance and seizure resistance, but has
oil repellency and a relatively large contact angle of lubricating
oil. On the other hand, ultra-high-molecular-weight-polyethylene
particles have a poorer sliding property than fluorine resin, but
have lipophilicity and a relatively small contact angle of
lubricating oil. Alternatively, melamine cyanurate (MCA), calcium
fluoride, and soft metal, such as copper and tin, may be used as
the solid lubricant.
[0018] In addition to the binder resin and the solid lubricant, the
first and second slide layers may each contain additives. As the
additives, an additive may be used that improves hardness of the
first and second slide layers, such as hard particles of, for
example, titanium dioxide, tricalcium phosphate, alumina, silica,
silicon carbide, and silicon nitride.
[0019] The first and second slide layers may each also contain a
surfactant, a coupling agent, a processing stabilizer, and an
antioxidant, for example.
[0020] It is preferable that the solid lubricant of the first slide
layer contains ultra high molecular weight polyethylene, and the
solid lubricant of the second slide layer contains fluorine resin.
Since fluorine resin has oil repellency and ultra high molecular
weight polyethylene has lipophilicity, as described above, the
solid lubricant of the first slide layer that contains ultra high
molecular weight polyethylene and the solid lubricant of the second
slide layer that contains fluorine resin surely implement the
present invention.
[0021] A swash plate compressor according to the present invention
has a significant operational advantage if the swash-plate chamber
directly communicates with an evaporator. That is, in a swash plate
compressor in which a swash-plate chamber directly communicates
with an evaporator, liquid refrigerant that has returned into the
swash-plate chamber from the evaporator is likely to wash away
lubricating oil on shoes and a swash plate. Consequently, a first
slide layer between the swash plate and the shoes is likely to be
worn and cause seizure. On the contrary, a first slide layer has
high oil wettability in a swash plate compressor according to the
present invention, and thus refrigerant is less likely to wash away
lubricating oil on the first slide layer even if the swash-plate
chamber directly communicates with an evaporator. Even if
lubricating oil is washed away, lubricating oil between the
cylinder bores and the pistons moves to the swash-plate chamber and
into between the swash plate and the shoes. Consequently,
lubricating oil is likely to be supplied to between the swash plate
and the shoes.
[0022] A swash plate compressor according to the present invention
has a significant operational advantage if the swash plate
compressor further includes: a linkage that is disposed within the
swash-plate chamber and allows a change in the inclination angle of
the swash plate; and an actuator that is disposed within the
swash-plate chamber and changes the inclination angle of the swash
plate. It is preferable that the actuator includes a partition body
that is rotatable with the drive shaft within the swash-plate
chamber, a movable body that is rotatable with the drive shaft
within the swash-plate chamber and moves with respect to the
partition body in an axis direction of the drive shaft to change
the inclination angle, a control pressure chamber that is defined
by the partition body and the movable body and has a pressure
within the control pressure chamber that moves the movable body,
and a control mechanism that controls the pressure within the
control pressure chamber.
[0023] That is, such a swash plate compressor that includes a
linkage and an actuator has a swash-plate chamber, a volume of
which is smaller than that of a swash-plate chamber of a swash
plate compressor that changes an inclination angle of a swash plate
by controlling pressure within a crank chamber. Therefore, such a
swash plate compressor has a difficulty in supplying lubricating
oil to a first slide layer between a swash plate and shoes.
Consequently, the first slide layer between the swash plate and the
shoes is likely to be worn and cause seizure. On the contrary, a
swash plate compressor according to the present invention has high
oil wettability of a first slide layer. Consequently, refrigerant
is less likely to wash away lubricating oil on the first slide
layer even if a swash-plate chamber includes a linkage and an
actuator and thus has a small volume.
Advantageous Effects of Invention
[0024] A swash plate compressor according to the present invention
has excellent durability.
BRIEF DESCRIPTION OF DRAWINGS
[0025] FIG. 1 is a cross-sectional view illustrating a swash plate
compressor according to a first embodiment.
[0026] FIG. 2 is a schematic diagram illustrating a control
mechanism related to the swash plate compressor according to the
first embodiment.
[0027] FIG. 3 is an enlarged cross-sectional view illustrating a
swash plate, shoes, and a piston of the swash plate compressor
according to the first embodiment.
[0028] FIG. 4 is a schematic cross-sectional view illustrating a
swash-plate main body and a first slide layer of the swash plate
compressor according to the first embodiment.
[0029] FIG. 5 is an enlarged cross-sectional view illustrating a
cylinder bore and a piston of the swash plate compressor according
to the first embodiment.
[0030] FIG. 6 is a schematic cross-sectional view illustrating a
piston main body and a second slide layer of the swash plate
compressor according to the first embodiment.
DESCRIPTION OF EMBODIMENT
[0031] Hereinafter, a first embodiment of the present invention
will be described referring to the drawings. In FIG. 1, a left side
of a compressor is defined as a front side, a right side of the
compressor is defined as a rear side, an upper side of the
compressor is defined as an upper side, and a lower side of the
compressor is defined as a lower side. Each direction in FIGS. 3
and 5 matches the corresponding direction in FIG. 1.
[0032] A swash plate compressor (hereinafter referred to as a
compressor) according to the first embodiment includes a housing 1,
a drive shaft 3, a swash plate 5, a plurality of pairs of shoes 7a
and 7b, a plurality of pistons 9, a linkage 11, and an actuator 13,
as illustrated in FIG. 1, and also includes a control mechanism 15
illustrated in FIG. 2.
[0033] As illustrated in FIG. 1, the housing 1 includes a front
housing 17, a rear housing 19, a first cylinder block 21, and a
second cylinder block 23.
[0034] The front housing 17 is on the front side of the compressor.
The rear housing 19 is on the rear side of the compressor. The
first cylinder block 21 and the second cylinder block 23 are
between the front housing 17 and the rear housing 19.
[0035] The front housing 17 includes a first suction chamber 27a
and a first discharge chamber 29a. The first suction chamber 27a is
on an inner side of the front housing 17. The first discharge
chamber 29a is on an outer side of the front housing 17.
[0036] The rear housing 19 includes the control mechanism 15. The
rear housing 19 includes a second suction chamber 27b, a second
discharge chamber 29b, and a pressure adjusting chamber 31. The
second suction chamber 27b is on an inner side of the rear housing
19. The second discharge chamber 29b is on an outer side of the
rear housing 19. The pressure adjusting chamber 31 is at a central
portion of the rear housing 19. A discharge passage (not
illustrated) connects the first discharge chamber 29a with the
second discharge chamber 29b. The discharge passage includes an
outlet (not illustrated).
[0037] A swash-plate chamber 33 is formed within the first cylinder
block 21 and the second cylinder block 23. The swash-plate chamber
33 is substantially at the center of the housing 1. The swash-plate
chamber 33 directly communicates with an evaporator (not
illustrated) through an inlet 330 of the second cylinder block
23.
[0038] The first cylinder block 21 includes a plurality of first
cylinder bores 21a that are concentrically arranged at equal
angular intervals, and are parallel with each other. The first
cylinder block 21 also includes a first shaft hole 21b through
which the drive shaft 3 is inserted. The first cylinder block 21
also includes a first suction passage 37a that connects the
swash-plate chamber 33 with the first suction chamber 27a.
[0039] A first valve unit 39 is disposed between the front housing
17 and the first cylinder block 21. The first valve unit 39
includes suction ports 39b and discharge ports 39a. The number of
the suction ports 39b is the same as that of the first cylinder
bores 21a. The number of the discharge ports 39a is the same as
that of the first cylinder bores 21a. The suction ports 39b connect
the respective first cylinder bores 21a with the first suction
chamber 27a through a suction valve (not illustrated). The
discharge ports 39a connect the respective first cylinder bores 21a
with the first discharge chamber 29a through a discharge valve (not
illustrated). The first valve unit 39 also includes a communication
hole 39c. The first suction chamber 27a communicates with the
swash-plate chamber 33 through the communication hole 39c and the
first suction passage 37a.
[0040] The second cylinder block 23 includes a plurality of second
cylinder bores 23a, similarly as the first cylinder block 21. The
second cylinder block 23 also includes a second shaft hole 23b
through which the drive shaft 3 is inserted. The second shaft hole
23b communicates with the pressure adjusting chamber 31. The second
cylinder block 23 also includes a second suction passage 37b that
connects the swash-plate chamber 33 with the second suction chamber
27b.
[0041] A second valve unit 41 is disposed between the rear housing
19 and the second cylinder block 23. The second valve unit 41
includes suction ports 41b and discharge ports 41a, similarly as
the first valve unit 39. The number of the suction ports 41b is the
same as that of the second cylinder bores 23a. The number of the
discharge ports 41a is the same as that of the second cylinder
bores 23a. The suction ports 41b connect the respective second
cylinder bores 23a with the second suction chamber 27b through a
suction valve 51 (see FIG. 5). The discharge ports 41a connect the
respective second cylinder bores 23a with the second discharge
chamber 29b through a discharge valve 52 (see FIG. 5). The second
valve unit 41 also includes a communication hole 41c. The second
suction chamber 27b communicates with the swash-plate chamber 33
through the communication hole 41c and the second suction passage
37b.
[0042] The first and second suction chambers 27a and 27b and the
swash-plate chamber 33 communicate with each other through the
first and second suction passages 37a and 37b. Consequently,
pressures within the first and second suction chambers 27a and 27b
and a pressure within the swash-plate chamber 33 are substantially
equal (more specifically, the pressure in the swash-plate chamber
33 is slightly higher than those in the first and second suction
chambers 27a and 27b due to effect of blow-by gas). Since
refrigerant gas that has passed through the evaporator flows into
the swash-plate chamber 33 through the inlet 330, the pressure
within the swash-plate chamber 33 and the pressures within the
first and second suction chambers 27a and 27b are lower than those
within the first and second discharge chambers 29a and 29b.
[0043] The swash plate 5, the actuator 13, and a flange 3a are
attached to the drive shaft 3. The drive shaft 3 is inserted
through the first and second shaft holes 21b and 23b within the
first and second cylinder blocks 21 and 23. Since the first and
second shaft holes 21b and 23b pivotally support the drive shaft 3,
the drive shaft 3 is rotatable on a rotary-shaft axis O within the
swash-plate chamber 33.
[0044] An axial passage 3b and a radial passage 3c extend through
the drive shaft 3. The axial passage 3b extends forward in the
rotary-shaft-axis-O direction from a rear end of the drive shaft 3.
The radial passage 3c radially extends from a front end of the
axial passage 3b and opens on an outer peripheral surface of the
drive shaft 3. A rear end of the axial passage 3b leads to the
pressure adjusting chamber 31. On the other hand, the radial
passage 3c leads to a control pressure chamber 13c described
below.
[0045] As illustrated in FIGS. 1 and 3, the swash plate 5 has an
annular flat-plate-like shape. The swash plate 5 includes a
swash-plate main body 5a and a first slide layer 5b. The first
slide layer 5b is formed on each of a front surface and a rear
surface of the swash-plate main body 5a. The swash plate 5 is fixed
to a ring plate 45. The ring plate 45 has an annular
flat-plate-like shape and includes an insertion hole 45a at a
central portion of the ring plate 45. The drive shaft 3 is inserted
through the insertion hole 45a so that the swash plate 5 is
attached to the drive shaft 3, and the swash plate 5 is disposed
within the swash-plate chamber 33.
[0046] As illustrated in FIG. 1, the linkage 11 includes a lug arm
49. The lug arm 49 is disposed within the swash-plate chamber 33,
and is behind the swash plate 5. The lug arm 49 has a substantially
L shape from one end side of the lug arm 49 to the other end side
of the lug arm 49.
[0047] A first pin 47a connects one end side of the lug arm 49 with
an upper-end side of the ring plate 45. Consequently, the one end
side of the lug arm 49 is swingably supported in such a manner that
the one end side of the lug arm 49 is swingable on a first swing
shaft axis M1 with respect to one end side of the ring plate 45,
that is, the swash plate 5. The first swing shaft axis M1 is a
shaft axis of the first pin 47a.
[0048] A second pin 47b connects the other end side of the lug arm
49 with a support member 43 that is pressed into a rear-end side of
the drive shaft 3. Consequently, the other end side of the lug arm
49 is swingably supported in such a manner that the other end side
of the lug arm 49 is swingable on a second swing shaft axis M2 with
respect to the support member 43, that is, the drive shaft 3. The
second swing shaft axis M2 is a shaft axis of the second pin
47b.
[0049] In the compressor, the linkage 11 connects the swash plate 5
with the drive shaft 3 so that the swash plate 5 is synchronously
rotatable with the drive shaft 3. Further, both ends of the lug arm
49 swing on the first swing shaft axis M1 and the second swing
shaft axis M2, respectively, to allow a change in an inclination
angle of the swash plate 5. That is, the linkage 11 allows a change
in the inclination angle of the swash plate 5.
[0050] As illustrated in FIGS. 1 and 5, each piston 9 includes a
piston main body 9a and a second slide layer 9b. The second slide
layer 9b is formed on a whole surface of the piston main body 9a.
Each piston 9 includes a first piston head 9c at a front-end side
of the piston 9 and a second piston head 9d at a rear-end side of
the piston 9. The first piston heads 9c are reciprocatably
accommodated within the respective first cylinder bores 21a, and
form respective first compression chambers 21d. The second piston
heads 9d are reciprocatably accommodated within the respective
second cylinder bores 23a, and form respective second compression
chambers 23d. Each piston 9 includes a recess 9e.
[0051] As illustrated in FIGS. 1 and 3, the shoes 7a and 7b each
have a hemispherical shape. The shoes 7a and 7b are disposed within
the respective recesses 9e. The shoes 7a and 7b slide on the swash
plate 5. The shoes 7a and 7b convert rotation of the swash plate 5
into reciprocation of the respective pistons 9. Consequently, the
pairs of shoes 7a and 7b allow the respective pistons 9 to make
strokes that depend on an inclination angle of the swash plate 5 to
reciprocate within the respective first and second cylinder bores
21a and 23a.
[0052] As illustrated in FIG. 1, the actuator 13 is disposed within
the swash-plate chamber 33, and is in front of the swash plate 5.
The actuator 13 includes a partition body 13a, a movable body 13b,
and the control pressure chamber 13c.
[0053] The partition body 13a has a disk-like shape. The drive
shaft 3 is inserted into the partition body 13a. The partition body
13a is fixed to the drive shaft 3 and is rotatable with the drive
shaft 3.
[0054] The movable body 13b is between the flange 3a and the swash
plate 5. The movable body 13b has a bottomed-cylindrical shape. The
drive shaft 3 is inserted into the movable body 13b. The movable
body 13b is rotatable with the drive shaft 3. The partition body
13a is slidably disposed within the movable body 13b. The movable
body 13b is movable with respect to the partition body 13a in the
rotary-shaft-axis-O direction of the drive shaft 3. The movable
body 13b faces the linkage 11 with the swash plate 5 therebetween.
Consequently, the actuator 13 is rotatable on the rotary-shaft axis
O with the drive shaft 3.
[0055] An attachment portion 13d is formed at a rear end of the
movable body 13b. A third pin 47c connects the attachment portion
13d with a lower-end side of the ring plate 45. Consequently, the
other end side of the ring plate 45 is swingably supported in such
a manner that the other end side of the ring plate 45 is swingable
on a third swing shaft axis M3 with respect to the lower-end side
of the ring plate 45, that is, the swash plate 5. The third swing
shaft axis M3 is a shaft axis of the third pin 47c. As a result,
the movable body 13b is connected to the swash plate 5.
[0056] The partition body 13a and the movable body 13b define the
control pressure chamber 13c. The radial passage 3c and the axial
passage 3b connect the control pressure chamber 13c with the
pressure adjusting chamber 31. A pressure within the control
pressure chamber 13c moves the movable body 13b. Consequently, the
movable body 13b is movable with respect to the partition body 13a
in the rotary-shaft-axis-O direction of the drive shaft 3 to change
an inclination angle of the swash plate 5. That is, the actuator 13
is configured to change the inclination angle of the swash plate
5.
[0057] As illustrated in FIG. 2, the control mechanism 15 includes
a bleed passage 15a and a supply passage 15b as control passages, a
control valve 15c, and an orifice 15d. The control mechanism 15
controls the pressure within the control pressure chamber 13c
through the bleed passage 15a, the supply passage 15b, the control
valve 15c, and the orifice 15d.
[0058] The bleed passage 15a connects the second suction chamber
27b with the pressure adjusting chamber 31. The axial passage 3b
and the radial passage 3c connect the pressure adjusting chamber 31
with the control pressure chamber 13c, That is, the second suction
chamber 27b communicates with the control pressure chamber 13c. The
orifice 15d is disposed within the bleed passage 15a to decrease a
flow rate of refrigerant gas that flows through the bleed passage
15a.
[0059] The supply passage 15b connects the second discharge chamber
29b with the pressure adjusting chamber 31. The axial passage 3b
and the radial passage 3c connect the pressure adjusting chamber 31
with the control pressure chamber 13c. That is, the second
discharge chamber 29b and the control pressure chamber 13c
communicate with each other. The axial passage 3b and the radial
passage 3c as control passages form parts of the bleed passage 15a
and the supply passage 15b.
[0060] The control valve 15c is disposed within the supply passage
15b. The control valve 15c adjusts an opening degree of the supply
passage 15b based on a pressure within the second suction chamber
27b, and adjusts a flow rate of refrigerant gas that flows through
the supply passage 15b. The control valve 15c may be a conventional
one.
[0061] As a characteristic configuration of the compressor
according to the first embodiment, the first slide layer 5b is
formed on each of a front surface and a rear surface of the
swash-plate main body 5a, as illustrated in FIG. 3. The swash-plate
main body 5a, that is, the swash plate 5 except the first slide
layer 5b is made of iron-based metal (i.e., iron or iron alloy that
primarily contains iron. The same applies hereinafter.). The
swash-plate main body 5a may be made of aluminum-based metal (i.e.,
aluminum or aluminum alloy that primarily contains aluminum. The
same applies hereinafter.).
[0062] As illustrated in FIG. 4, the first slide layer 5b contains
binder resin 70 that is polyimide-imide (PAD, and solid lubricants
that are ultra-high-molecular-weight-polyethylene (UHPE) particles
81, molybdenum dioxide (MoS.sub.2) 83, and graphite 84. Slide Layer
1 in Table 1 shows percent composition (volume %) of the first
slide layer 5b. The UHPE has an average particle size of 1 to 30
.mu.m, and an average molecular weight of 500,000. If the particle
size is smaller than 1 .mu.m, UHPE is likely to coagulate and is
difficult to deal with. If the particle size is larger than 30
.mu.m, surface roughness of the layer becomes larger and slide
performance deteriorates. If the molecular weight is smaller than
500,000, wear resistance deteriorates.
TABLE-US-00001 TABLE 1 Contact Angle of Composition [vol. %]
Lubricating PAI UHPE MoS.sub.2 Graphite PTFE Oil (.degree.) Slide
50 18 18 14 -- 8.4 Layer 1 Slide 50 28 12 10 -- 8.5 Layer 2 Slide
50 -- 30 20 -- 8.7 Layer 3 Slide 80 -- -- -- 20 38.0 Layer 4 Slide
70 -- -- -- 30 43.0 Layer 5
[0063] The shoes 7a and 7b that slide on a slide surface of the
first slide layer 5b are also made of iron-based metal. The shoes
7a and 7b may be made of aluminum-based metal. Alternatively, the
shoes 7a and 7b may each include a shoe main body and a first slide
layer 5b.
[0064] As illustrated in FIG. 5, the second slide layer 9b is
formed on the whole surface of each piston 9. The piston main body
9a, that is, each piston 9 except the second slide layer 9b is made
of aluminum-based metal. The piston main body 9a may be made of
iron-based metal.
[0065] As illustrated in FIG. 6, the second slide layer 9b contains
binder resin 70 that is PAI, and PTFE 82 that is solid lubricant.
Slide Layer 4 in Table 1 shows percent composition (volume %) of
the second slide layer 9b. That is, the solid lubricant contains
only PTFE 82.
[0066] The first and second cylinder blocks 21 and 23 on which a
slide surface of the second slide layer 9b slides are made of
aluminum-based metal. The first and second cylinder blocks 21 and
23 may be made of iron-based metal. Alternatively, the first
cylinder block 21 may include a first-cylinder-block main body and
a second slide layer 9b, and the second cylinder block 23 may
include a second-cylinder-block main body and a second slide layer
9b.
[0067] The first and second slide layers 5b and 9b are formed as
follows: First, PAI varnish is blended with each solid lubricant,
and is fully stirred. Then the mixture is passed through three roll
mills to obtain a coating material. The coating material is
optionally diluted with a solvent, such as n-methyl-2-pyrrolidone,
1,3-dimethyl-2-imidazolidinone, or xylene, for types of coating
methods (spray coating, roll coating, etc.), or for adjustment of
viscosity, or adjustment of concentration of solid material. Then
the swash-plate main body 5a and the piston main body 9a are coated
with the coating material, the coating is dried and then baked
(230.degree. C..times.one hour). A thickness of the formed film is
adjusted to 20 .mu.m to form the first and second slide layers 5b
and 9b.
[0068] A compressor according to the first embodiment obtained in
this way has the inlet 330 illustrated in FIG. 1 and connected to
the evaporator by a pipe, and the outlet connected to a condenser
(not illustrated) by a pipe. The compressor, the evaporator, an
expansion valve, the condenser, and the like constitute a
refrigeration circuit for a vehicle air conditioner.
[0069] In the compressor, rotation of the drive shaft 3 rotates the
swash plate 5 so that the pistons 9 reciprocate within the
respective first and second cylinder bores 21a and 23a.
Consequently, the first and second compression chambers 21d and 23d
change respective volumes based on piston strokes. Therefore,
refrigerant gas drawn into the swash-plate chamber 33 through the
inlet 330 from the evaporator passes the first and second suction
chambers 27a and 27b, is compressed within the first and second
compression chambers 21d and 23d, and is discharged into the first
and second discharge chambers 29a and 29b. The refrigerant gas
within the first and second discharge chambers 29a and 29b is
discharged into the condenser through the outlet.
[0070] During that time, the first slide layer 5b allows the shoes
7a and 7b to appropriately slide on the swash plate 5 in the
compressor. Further, the second slide layer 9b allows the pistons 9
to appropriately slide on the respective first and second cylinder
bores 21a and 23a.
[0071] Especially in the compressor, the first slide layer 5b has
higher oil wettability than the second slide layer 9b.
Consequently, lubricating oil is allowed to move to the swash-plate
chamber 33 through between the cylinder bores 21a and 23a and the
pistons 9, and much lubricating oil is allowed to be present
between the swash plate 5 and the shoes 7a and 7b. Therefore, much
lubricating oil is allowed to exist even between the swash plate 5
and the shoes 7a and 7b. Therefore, wear or seizure is less likely
to occur between the swash plate 5 and the shoes 7a and 7b.
[0072] Further, much lubricating oil is not allowed to exist
between the first and second cylinder bores 21a and 23a and the
pistons 9. Therefore, lubricating oil between the first and second
cylinder bores 21a and 23a and the pistons 9 is allowed to move to
the swash-plate chamber 33.
[0073] Therefore, the compressor according to the first embodiment
has excellent durability.
[0074] (Test)
[0075] Test pieces that had Slide Layers 1 to 5, respectively, were
prepared to confirm the effect of the above first embodiment. A
base material of each test piece was cast iron. The base material
corresponds to the swash-plate main body or the piston main body.
Table 1 shows percent composition (volume %) of binder resin and
solid lubricant of Slide Layers 1 to 5 of the test pieces. The test
pieces had the same weight.
[0076] Table 2 shows basic characteristics of fluorine resin (PTFE)
and ultra-high-molecular-weight-polyethylene (UHPE) particles that
constituted composition of Slide Layers 1, 2, 4, and 5.
TABLE-US-00002 TABLE 2 Items PTFE UHPE Specific Gravity -- 2.15
0.94 Average Particle .mu.m 8 10 Size Average .times.10.sup.4 --
180 Molecular Weight Melting Point .degree. C. 325 135
[0077] Table 1 shows contact angles of lubricating oil of Slide
Layers 1 to 5 of the test pieces. Polyalkylene glycol (FAG) was
used as the lubricating oil. Polyol ester (POE) may be used as the
lubricating oil. Table 1 shows that Slide Layers 1 and 2 had small
contact angles, and thus had lipophilicity. On the other hand,
Table 1 shows that Slide Layers 4 and 5 had larger contact angles
than Slide Layers 1 and 2, and thus had oil repellency.
[0078] Slide Layers 1 to 3 of the test pieces were subjected to
Tests 1 and 2 described below.
[0079] Test 1: Ring-on-Disk Test
[0080] S45C was used as ring material. Coefficients of friction and
specific wear rates were determined under conditions of: no
lubrication (no lubricating oil), sliding speed: 9 m/s, and a load
of 220 N.
[0081] Test 2: Swash Plate/Shoe, Step Loading Seizure Test
[0082] A step loading seizure test was performed under conditions
of: lubrication (lubricating oil: 25 g/min of refrigerator oil was
applied on a surface of a swash plate), a step loading increment of
400 N per five minutes, and a rotational speed of 1500 rpm. A load
that caused seizure was determined. Table 3 shows the results.
TABLE-US-00003 TABLE 3 Test 1 Test 2 Coefficient of Specific Wear
Rate .times. 10.sup.6 Seizure Load Friction [mm.sup.3/N m] [N]
Slide Layer 1 0.078 4.0 7,200 Slide Layer 2 0.073 2.7 6,800 Slide
Layer 3 0.099 15.1 5,000 Slide Layer 4 0.070 8.1 4,800 Slide Layer
5 0.072 8.8 4,000
[0083] Slide Layers 1 and 2 had lower coefficients of friction and
less wear than Slide Layer 3, and thus had improved seizure
resistance. This is because Slide Layers 1 and 2 contained UHPE as
solid lubricant.
[0084] Although the solid lubricant of Slide Layers 1 and 2
contained UHPE, solid lubricant of Slide Layers 4 and 5 contained
PTFE instead of UHPE. Therefore, Slide Layers 1 and 2 that
contained UHPE had less wear than Slide Layers 4 and 5 that
contained PTFE, and thus had improved seizure resistance.
Therefore, it is seen that Slide Layers 1 and 2 had improved
lipophilicity, and thus had improved oil wettability and formed oil
films, and thus had excellent wear resistance.
[0085] Although the present invention has been described based on
the first embodiment and Tests 1 and 2, the present invention is
not limited to the first embodiment. It is natural that the present
invention is appropriately modified and applied within a scope that
does not depart from the gist of the present invention.
INDUSTRIAL APPLICABILITY
[0086] The present invention is applicable to air conditioners, for
example.
REFERENCE SIGNS LIST
[0087] 1 housing [0088] 3 drive shaft [0089] 5 swash plate [0090]
5b first slide layer [0091] 7a, 7b shoe [0092] 9 piston [0093] 9b
second slide layer [0094] 11 linkage [0095] 13 actuator [0096] 13a
partition body [0097] 13b movable body [0098] 13c control pressure
chamber [0099] 15 control mechanism [0100] 33 swash-plate chamber
[0101] 21a first cylinder bore (cylinder bore) [0102] 23a second
cylinder bore (cylinder bore) [0103] 70 binder resin [0104] 81 UHPE
(ultra high molecular weight polyethylene) [0105] 82 PTFE (fluorine
resin)
* * * * *