U.S. patent application number 16/480223 was filed with the patent office on 2019-12-05 for compressor.
This patent application is currently assigned to DAIKIN INDUSTRIES, LTD.. The applicant listed for this patent is DAIKIN INDUSTRIES, LTD.. Invention is credited to Kazuhiro FURUSHO, Eiji KUMAKURA.
Application Number | 20190368493 16/480223 |
Document ID | / |
Family ID | 62978230 |
Filed Date | 2019-12-05 |
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United States Patent
Application |
20190368493 |
Kind Code |
A1 |
KUMAKURA; Eiji ; et
al. |
December 5, 2019 |
COMPRESSOR
Abstract
In a compressor compressing a refrigerant including hydrocarbon
fluoride prone to disproportionate, provided, on a contact portion
of the drive shaft and the bearing portion, is an elastic bearing
portion as a heat generation suppression portion suppressing
excessive heat generation due to line contact of an end edge
portion of the bearing portion with the drive shaft during rotation
of the drive shaft.
Inventors: |
KUMAKURA; Eiji; (Osaka-shi,
Osaka, JP) ; FURUSHO; Kazuhiro; (Osaka-shi, Osaka,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIKIN INDUSTRIES, LTD. |
Osaka-shi, Osaka |
|
JP |
|
|
Assignee: |
DAIKIN INDUSTRIES, LTD.
Osaka-shi, Osaka
JP
|
Family ID: |
62978230 |
Appl. No.: |
16/480223 |
Filed: |
January 19, 2018 |
PCT Filed: |
January 19, 2018 |
PCT NO: |
PCT/JP2018/001541 |
371 Date: |
July 23, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C 29/023 20130101;
F04C 2210/26 20130101; F04C 2240/40 20130101; F04C 29/04 20130101;
F04C 18/0215 20130101; F04C 2240/50 20130101; F04C 2240/60
20130101; F04C 23/008 20130101 |
International
Class: |
F04C 29/04 20060101
F04C029/04 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 30, 2017 |
JP |
2017-014219 |
Claims
1. A compressor compressing a refrigerant including hydrocarbon
fluoride prone to disproportionation, the compressor comprising: a
casing; a compression mechanism housed in the casing; an electric
motor driving the compression mechanism; a drive shaft connecting
the compression mechanism with the electric motor; a bearing
portion rotatably supporting the drive shaft; and a heat generation
suppression portion formed on a contact portion of the drive shaft
and the bearing portion, the heat generation suppression portion
suppressing excessive heat generation due to line contact of an end
edge portion of the bearing portion with the drive shaft during
rotation of the drive shaft.
2. The compressor of claim 1, wherein the end edge portion of the
bearing portion is provided with an elastic bearing portion formed
to be elastic due to thin structure in that an outer diameter of
the elastic bearing portion is smaller than that of a main body
portion except for the end edge portion, and the heat generation
suppression portion is made of the elastic bearing portion.
3. The compressor of claim 1, wherein the drive shaft includes, on
an engagement portion engaging with the bearing portion, a shaft
side crowning portion with an outer diameter thereof decreasing in
direction from a center portion toward an end edge portion of the
engagement portion, and the heat generation suppression portion is
made of the shaft side crowning portion.
4. The compressor of claim 1, wherein the bearing portion includes,
on an engagement portion engaging with the drive shaft, a bearing
side crowning portion with an inner diameter thereof increasing in
direction from a center portion toward an end edge portion of the
engagement portion, and the heat generation suppression portion is
made of the bearing side crowning portion.
5. The compressor of claim 1, wherein the end edge portion of the
bearing portion is provided with a bearing side oil groove portion
with its inner diameter larger than a main body portion except for
the end edge portion to store lubricant; the heat generation
suppression portion is made of the bearing side oil groove
portion.
6. The compressor of claim 1, wherein the drive shaft is provided
with, on a part of an engagement portion engaging with the bearing
portion, a shaft side oil groove portion configured to store
lubricant, and the heat generation suppression portion is made of
the shaft side oil groove portion.
7. The compressor of claim 1, wherein the refrigerant is a
refrigerant comprising HFO-1123.
8. The compressor of claim 2, wherein the refrigerant is a
refrigerant comprising HFO-1123.
9. The compressor of claim 3, wherein the refrigerant is a
refrigerant comprising HFO-1123.
10. The compressor of claim 4, wherein the refrigerant is a
refrigerant comprising HFO-1123.
11. The compressor of claim 5, wherein the refrigerant is a
refrigerant comprising HFO-1123.
12. The compressor of claim 6, wherein the refrigerant is a
refrigerant comprising HFO-1123.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a compressor and, in
particular, a configuration in a compressor compressing a
refrigerant including hydrocarbon fluoride prone to
disproportionation where heat generation is suppressed to prevent
disproportional reaction.
BACKGROUND ART
[0002] Conventionally, there has been known a refrigeration
apparatus including a refrigerant circuit to which a compressor is
connected and which performs a refrigeration cycle. Such
refrigeration apparatus has been widely applied to an
air-conditioning device etc. The above compressor performs a
compression phase of a refrigeration cycle. Various types of such a
compressor are known. Examples thereof include a rolling piston
type compressor, a swing piston type compressor, and a scroll type
compressor etc. For example, Patent Document 1 discloses a rolling
piston type compressor.
[0003] As disclosed in Patent Document 2 (WO 2012157764), HFO-1123
and a refrigerant mixture including HFO-1123 may be applied as a
refrigerant in the above refrigerant circuit and as a candidate for
a low GWP refrigerant. HFO-1123 is a refrigerant including
hydrocarbon fluoride prone to disproportionation
(self-decomposition) in accordance with generation of compounds
upon exerting any energy under a high pressure and at a high
temperature, as FIG. 19 shows the reaction tendencies of two types
of refrigerants (refrigerant A, refrigerant B). That is, the
disproportional reaction is a chemical reaction where molecules of
the same type react with each other, generating a different
product.
CITATION LIST
Patent Documents
[0004] [Patent Document 1] Japanese Unexamined Patent Publication
No. 2015-169089
[0005] [Patent Document 2] PCT International Publication No. WO
2012157764
SUMMARY OF THE INVENTION
Technical Problem
[0006] In case where a compressor using a refrigerant prone to
disproportionation is operated under a high load or at a high
rotating speed, when a partial contact occurs in a bearing
structure composed of a drive shaft (S) and a bearing (B) as shown
in FIG. 21, thereby causing resulting rapid local temperature rise,
the disproportional reaction (self-decomposition) of the above
refrigerant occurs in accordance with generation of compounds. The
resulting chain reaction causes rapid temperature rise and rapid
pressure rise. As a result, there may be a case where pipes are
broken and a refrigerant and compounds are ejected out of the
compressor. In particular, in a high-pressure dome compressor
having a casing an interior of which undergoes high pressure, the
refrigerant in the casing is subject to a high temperature and a
high pressure. Due to further rise in temperature and in pressure,
the above mentioned problem is likely to arise.
[0007] Further, when a compressor using a refrigerant prone to
disproportionation has been stopped for a long time, lubricant
drops down in the bearing. As a result, a shaft and the bearing are
likely to come in contact with each other in their metal parts at
the time of restart of the compressor. Hence, there is a growing
fear that the disproportional reaction occurs.
[0008] The present disclosure has been made in view of the above
problems, and it is an object of the present disclosure to provide
a compressor compressing a refrigerant including hydrocarbon
fluoride prone to disproportionation in which generation of a
partial contact at a bearing is prevented and rise in temperature
of the refrigerant is suppressed, thereby suppressing the
disproportional reaction of the refrigerant.
Solution to the Problem
[0009] A first aspect of the present disclosure is set a compressor
as a premise. The compressor compresses a refrigerant including
hydrocarbon fluoride prone to disproportionation, and comprises: a
casing (11); a compression mechanism (12) housed in the casing
(11); an electric motor (13) driving the compression mechanism
(12); a drive shaft (S) connecting the compression mechanism (12)
with the electric motor (13); and a bearing portion (B) rotatably
supporting the drive shaft (S).
[0010] The compressor includes, on a contact portion of the drive
shaft (S) and the bearing portion (B), a heat generation
suppression portion (1) suppressing excessive heat generation due
to line contact of an end edge portion of the bearing portion (B)
with the drive shaft (S) during rotation of the drive shaft
(S).
[0011] According to the first aspect, since the heat generation
suppression portion (1) is provided at the contact portion of the
drive shaft (S) and the bearing portion (B), when the compressor is
operated under a high load or at a high rpm, it is possible to
prevent a partial contact of the bearing portion and resulting
rapid local temperature rise Therefore, the disproportional
reaction of the refrigerant is less likely to occur in the
compressor using refrigerant prone to disproportionation. Further,
even when lubricant drops down in the bearing in the compressor
which has been stopped for a long time, it is possible to prevent
the disproportional reaction at the time of restart of the
compressor.
[0012] In a second aspect of the first aspect according to the
present disclosure, the end edge portion of the bearing portion (B)
is provided with an elastic bearing portion (2) formed to be
elastic due to thin structure in that an outer diameter of the
elastic bearing portion (2) is smaller than that of a main body
portion except for the end edge portion, and the heat generation
suppression portion (1) is made of the elastic bearing portion
(2).
[0013] According to the second aspect, the elastic bearing portion
(2) is provided as the heat generation suppression portion (1).
Accordingly, when the compressor is operated under a high load or
at a high rpm, it is possible to prevent the occurrence of a
partial contact in the bearing and thus resulting rapid local
temperature rise. Therefore, it is possible to prevent
disproportional reaction of the refrigerant in the compressor using
refrigerant prone to disproportionation.
[0014] In a third aspect of the first aspect according to the
present disclosure, the drive shaft (S) includes, on an engagement
portion engaging with the bearing portion (B), a shaft side
crowning portion (3) with an outer diameter thereof decreasing in
direction from a center portion toward an end edge portion of the
engagement portion, and the heat generation suppression portion (1)
is made of the shaft side crowning portion (3).
[0015] In a fourth aspect of the first aspect according to the
present disclosure, the bearing portion (B) includes, on an
engagement portion engaging with the drive shaft (S), a bearing
side crowning portion (4) with an inner diameter thereof increasing
in direction from a center portion toward an end edge portion of
the engagement portion, and the heat generation suppression portion
(1) is made of the bearing side crowning portion (4).
[0016] According to the third aspect, the shaft side crowning
portion (3) is provided as the heat generation suppression portion
(1), and according to the fourth aspect, the bearing side crowning
portion (4) is provided as the heat generation suppression portion
(1). Therefore, when a compressor is operated under a high load or
at a high rpm, it is possible to prevent the occurrence of a
partial contact in the bearing and thus resulting rapid local rise
in temperature. Hence, it is possible to prevent disproportional
reaction of the refrigerant in the compressor using refrigerant
prone to disproportionation.
[0017] In a fifth aspect of the first aspect according to the
present disclosure, the end edge portion of the bearing portion (B)
is provided with a bearing side oil groove portion (5) with its
inner diameter larger than a main body portion except for the end
edge portion to store lubricant; the heat generation suppression
portion (1) is made of the bearing side oil groove portion (5).
[0018] In a sixth aspect of the first aspect according to the
present disclosure, the drive shaft (S) is provided with, on a part
of an engagement portion engaging with the bearing portion (B), a
shaft side oil groove portion (6) configured to store lubricant,
and the heat generation suppression portion (1) is made of the
shaft side oil groove portion (6). For example, the shaft side oil
groove portion (6) may be provided, on a part of the engagement
portion of the drive shaft (S) with the bearing portion (B) to have
an outer diameter smaller than that of the main body portion except
for the above part so as to store oil.
[0019] According to the fifth aspect, the bearing side oil groove
portion (5) is provided as the heat generation suppression portion
(1), and according to the sixth aspect, the shaft side oil groove
portion (6) is provided as the heat generation suppression portion
(1). In each case, when a compressor is operated under a high load
or at a high rpm, providing oil coating makes it possible to
prevent the occurrence of a partial contact in the bearing and thus
resulting rapid local rise in temperature. Therefore, it is
possible to prevent disproportional reaction of the refrigerant in
the compressor using refrigerant prone to disproportionation.
[0020] In a seventh aspect of any one of the first to sixth aspects
of the present disclosure, the refrigerant is a refrigerant
comprising HFO-1123.
[0021] In the seventh aspect, a refrigerant including HFO-1123 is
used as the refrigerant. HFO-1123 is easily decomposed by OH
radicals in the atmosphere. Therefore, HFO-1123 less affects the
ozone layer and global warming. Further, the use of the refrigerant
including HFO-1123 makes it possible to improve the refrigeration
cycle performance of a refrigeration apparatus.
Advantages of the Invention
[0022] According to the first aspect, since the heat generation
suppression portion (1) is provided at a contact portion of the
drive shaft (S) and the bearing portion (B), when the compressor is
operated under a high load or at a high rpm, it is possible to
prevent a partial contact of the bearing portion and resulting
rapid local rise in temperature. As a result, in the compressor
using refrigerant prone to disproportionation, it is possible to
suppress a partial contact of the bearing and resulting rise in
temperature of the refrigerant, thereby preventing the
disproportional reaction of the refrigerant. Further, even when
lubricant drops down in the bearing in the compressor which has
been stopped for a long time, it is possible to prevent the
disproportional reaction at the time of restart of the compressor.
According to the first aspect, the above effects can be obtained
also in a high-pressure dome type compressor where high pressure
prevails in the casing.
[0023] According to the second aspect, the elastic bearing portion
(2) is provided as the heat generation suppression portion (1).
Therefore, when a compressor is operated under a high load or at a
high rpm, it is possible to prevent the occurrence of a partial
contact in the bearing and thus resulting rapid local temperature
rise. Hence, it is possible to prevent disproportional reaction of
the refrigerant with a simple configuration in a compressor using
the refrigerant prone to disproportionation.
[0024] According to the third aspect, the shaft side crowning
portion (3) is provided as the heat generation suppression portion
(1), and according to the fourth aspect, the bearing side crowning
portion (4) is provided as the heat generation suppression portion
(1). Accordingly, in each case, when a compressor is operated under
a high load or at a high rpm, it is possible to prevent the
occurrence of a partial contact in the bearing and thus resulting
rapid local temperature rise. Therefore, it is possible to prevent
disproportional reaction of the refrigerant with a simple
configuration in a compressor using the refrigerant prone to
disproportionation.
[0025] According to the fifth aspect, the bearing side oil groove
portion (5) is provided as the heat generation suppression portion
(1), and according to the sixth aspect, the shaft side oil groove
portion (6) is provided as the heat generation suppression portion
(1). Accordingly, in each case, when a compressor is operated under
a high load or at a high rpm, providing an oil coating makes it
possible to prevent the occurrence of a partial contact in the
bearing and thus resulting rapid local temperature rise. Therefore,
it is possible to prevent disproportional reaction of the
refrigerant with a simple configuration in a compressor using the
refrigerant prone to disproportionation.
[0026] According to the seventh aspect, a refrigerant including
HFO-1123 is used as the refrigerant. HFO-1123 is easily decomposed
by OH radicals in the atmosphere. Therefore, HFO-1123 less affects
the ozone layer and global warming. Further, the use of the
refrigerant including HFO-1123 makes it possible to improve the
refrigeration cycle performance of a refrigeration apparatus.
Hence, it is possible to put such compressor to practical use which
less affects the ozone layer and global warming and makes it
possible to improve the refrigeration cycle performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIG. 1 is a cross-sectional view illustrating a bearing
structure of a compressor according to a first embodiment.
[0028] FIG. 2 is a vertical cross-sectional view of a swing piston
type compressor according to the first embodiment.
[0029] FIG. 3 is an enlarged view of an essential part of FIG.
2.
[0030] FIG. 4 is a horizontal cross-sectional view of a compression
mechanism.
[0031] FIG. 5 is a vertical cross-sectional view of the swing
piston type compressor according to a first variation of the first
embodiment.
[0032] FIG. 6 is a horizontal cross-sectional view of a compression
mechanism according to the first variation of the first
embodiment.
[0033] FIG. 7 is a plan view of a rear head according to the first
variation of the first embodiment.
[0034] FIG. 8 is a vertical cross-sectional view of a scroll
compressor according to a second variation of the first
embodiment.
[0035] FIG. 9 is a cross-sectional view of a bearing structure of a
compressor according to a second embodiment.
[0036] FIG. 10 is a vertical cross-sectional view of a scroll
compressor according to the second embodiment.
[0037] FIG. 11 is a cross-sectional view of a bearing structure of
a compressor according to a third embodiment.
[0038] FIG. 12 is a vertical cross-sectional view of a swing piston
type compressor according to the third embodiment.
[0039] FIG. 13 is an enlarged view of an essential part of a
bearing structure.
[0040] FIG. 14 is a cross-sectional view of a bearing structure of
the compressors according to the fourth and the fifth
embodiments.
[0041] FIG. 15 is a vertical cross-sectional view of a
reciprocation type compressor according to the fourth
embodiment.
[0042] FIG. 16 is a partial cross-sectional view of a scroll
compressor according to the fifth embodiment.
[0043] FIG. 17 is a partial cross-sectional view of a scroll
compressor according to a first variation of the fifth
embodiment.
[0044] FIG. 18 is a partial cross-sectional view of a scroll
compressor according to a second variation of the fifth
embodiment.
[0045] FIG. 19 is a graph showing reaction tendency of refrigerants
prone to disproportionation.
[0046] FIG. 20 is a rough cross-sectional view of a bearing
structure of a conventional compressor.
DESCRIPTION OF EMBODIMENTS
[0047] In the following, embodiments will be described in detail
with reference to the drawings. The present embodiment relates to a
compressor compressing refrigerants including hydrocarbon fluoride
prone to disproportionation. The compressor is provided in a
refrigerant circuit and performs compression phase of a
refrigeration cycle. As specifically explained in connection with
the first to the fifth embodiments described later, the compressor
includes a casing, a compression mechanism housed in the casing,
and an electric motor driving the compression mechanism. As shown
in FIG. I described later, the compressor further includes a drive
shaft (S) connecting the compression mechanism with the electric
motor and a bearing portion (B) rotatably supporting the drive
shaft (S). The compressor includes, on a contact portion of the
drive shaft (S) and the bearing portion (B), a heat generation
suppression portion (1) suppressing excessive heat generation due
to line contact of an end edge portion of the bearing portion (B)
with the drive shaft (S) during rotation of the drive shaft
(S).
[0048] First Embodiment
[0049] The first embodiment will be described.
[0050] First, a schematic configuration of the bearing structure
will be described. In this first embodiment, the heat generation
suppression portion (1) is configured of an elastic bearing portion
(2) schematically shown in FIG. 1. As illustrated, in the first
embodiment, an end edge portion of the bearing portion (B) is
provided with, on the contact portion of the drive shaft (S) and
the bearing portion (B), the elastic bearing portion (2) formed to
be elastic due to thin structure, since the outer diameter of the
elastic bearing portion (2) is smaller than that of a main body
portion except for the above end edge. FIG. 1 shows a state in
which the drive shaft (S) is inclined. The elastic bearing portion
(2) elastically deforms in accordance with the inclination of the
drive shaft.
[0051] The specific configuration of the compressor (100) will be
described next. As shown in FIG. 2, the compressor (10) of the
first embodiment is a swing piston type compressor (100). The
elastic bearing portion (2) is applied as a bearing structure of
the swing piston type compressor (100). This swing piston type
compressor (100) includes a casing (110), a compression mechanism
(120) housed in the casing (110), an electric motor (130) driving
the compression mechanism (120), a drive shaft (140) (drive shaft
(S) of FIG. 1) connecting the compression mechanism (120) and the
electric motor (130), and a bearing portion (150) (bearing portion
(B) of FIG. 1) rotatably supporting the drive shaft (140).
[0052] The casing (110) includes a barrel (111) formed into a
vertically long cylindrical shape, an upper end plate (112) fixed
on an upper end of the barrel (111), and a lower end plate (113)
fixed on an lower end of the barrel (111). The casing (110) is
provided with a suction pipe (114) passing through the barrel (111)
and a discharge pipe (115) passing through the upper end plate
(112).
[0053] As shown in FIG. 2 and FIG. 3, the compression mechanism
(120) includes a cylinder (121) which is formed into an annular
shape and has space defining a cylinder chamber (compression
chamber), a front head (122) fixed on an upper end face of the
cylinder (121), and a rear head (123) fixed on a lower end face of
the cylinder (121). The front head (122), the cylinder (121) and
the rear head (123) are integrally fastened with each other through
a fastening member such as a bolt. The compression mechanism (120)
is fixed on the casing (110) through joining the cylinder (121) on
the barrel (111) of the casing (110). Further, the cylinder chamber
of the compression mechanism (120) is provided with a piston (125)
eccentrically rotating in the cylinder chamber.
[0054] The electric motor (130) is provided with a stator (131)
fixed to the casing (110) above the compression mechanism (120) and
a rotor (132) located inside the stator (131) and rotating with
respect to the stator (131).
[0055] The drive shaft (140) is fixed to the rotor (132) of the
electric motor (130) and rotates integrally with the rotor (132).
Further, the drive shaft (140) has an eccentric portion (141)
engaging with the piston (125) of the compression mechanism (120),
and is rotatably supported by the bearing portion (150) of the
front head (122) located above the piston (125) and by the bearing
portion (150) of the rear head (123) located below the piston
(125). As shown in FIG. 4, the piston (125) integrally includes an
annular portion (125a) and a blade (125b) extending from the
annular portion (125a) toward an outer periphery. The blade (125b)
is swingably supported by a swing bush (127) attached to the piston
(125).
[0056] The upper and lower end edge portions of the bearing portion
(150) of the front head (122) are each provided with an elastic
bearing portion (2) formed to be elastic due to thin structure,
since the outer diameter of the elastic bearing portion (2) is
smaller than that of a main body portion (1a) except for the
corresponding end edge. The upper end edge portion of the bearing
portion (150) of the rear head (123) includes an elastic bearing
portion (2) whose outer diameter is smaller than that of the main
body portion (1a) of the bearing portion (150).
[0057] Refrigerant
[0058] As a refrigerant filled in the refrigerant circuit and
compressed by this swing piston type compressor (100), it is
possible to use a single component refrigerant including
hydrocarbon fluoride prone to disproportionate or a refrigerant
mixture including hydrocarbon fluoride prone to disproportionation
and at least one refrigerant other than the refrigerant including
hydrocarbon fluoride.
[0059] As a hydrocarbon fluoride prone to disproportionation, it is
possible to use hydrofluoroolefin (HFO) including a carbon-carbon
double bond which less affects the ozone layer and global warming
and is easily decomposed by OH radicals. Specifically, as an
example of such HFO refrigerants, it is preferable to use
trifluoroethylene (HFO-1123) having excellent performance disclosed
in Japanese Unexamined Patent Application Publication No. 2015-7257
and Japanese Unexamined Patent Application Publication No.
2016-28119. Further, it is possible to use, as HFO refrigerants
other than HFO-1123, such refrigerants prone to disproportionation
which are selected from 3,3,3-trifluoropropen (HFO-1243zf),
1,3,3,3-tetrafluoropropen (HFO-1234ze), 2-fluoropropen
(HFO-1261yf), 2,3,3,3-tetrafluoropropen (HFO-1234yf), and
1,1,2-trifluoropropen (HFO-1243yc) disclosed in Japanese Unexamined
Patent Application Publication No. H04-110388 and
1,2,3,3,3-pentafluoropropen (HFO-1225ye),
trans-1,3,3,3-tetrafluoropropen (HFO-1234ze(E)) and
cis-1,3,3,3-tetrafluoropropen (HFO-1234ze(Z)) disclosed in Japanese
Translation of Unexamined Patent Application Publication No.
2006-512426, as long as they are prone to disproportionation.
Examples of hydrocarbon fluoride prone to disproportionation may
include acetylenic hydrocarbon fluoride including a carbon-carbon
triple bond.
[0060] Further, in case where a refrigerant mixture including
hydrocarbon fluoride prone to disproportionation is used, the
refrigerant mixture preferably includes the above-mentioned
HF-1123. For example, a refrigerant mixture made of HFO-1123 and
HFC-32 may be used. It is preferable that the composition ratio of
this refrigerant mixture is, for example, as follows: HFO-1123:
HFC-32=40:60 (unit: weight %). Moreover, a refrigerant mixture made
of HFO-1123, HFC-32 and HFO-1234yf may also be used. It is
preferable that the composition ratio of this refrigerant mixture
is, for example, as follows: HFO-1123: HFC-32: HFO-1234yf=40:44:16
(unit: weight %). Further, AMOLEA X series refrigerants (trademark:
manufactured by Asahi Glass Co., Ltd.) or AMOLEA Y series
refrigerants (trademark: manufactured by Asahi Glass Co., Ltd.) may
also be used as refrigerant mixtures.
[0061] As other refrigerants included in refrigerant mixtures,
other substances which vaporize and liquefy together with HFO-1123
such as hydrocarbons (HC), hydrofluorocarbons (HFC),
hydrochlorofluoroolefins (HCFO), and chlorofluoroolefins (CFO) may
appropriately be used.
[0062] HFC is a component that improves performance, and less
affects the ozone layer and global warming. It is preferable to use
HFC having five or fewer carbon atoms. Specifically, examples of
HFC include difluoromethane (HFC-32), difluoroethane (HFC-152a),
trifluoroethane (HFC-143), tetrafluoroethane (HFC-134),
pentafluoroethane (HFC-125), pentafluoropropane (HFC-245ca),
hexafluoropropane (HFC-236fa), heptafluoropropane (HFC-227ea),
pentafluorobutane (HFC-365), and heptafluorocyclopentane (HFCP).
Among the HFCs mentioned above, difluoromethane (HFC-32),
1,1-difluoroethane (HFC-152a), 1,1,2,2-tetrafluoroethane (HFC-134),
and 1,1,1,2-tetrafluoroethane (HFC-134a) and pentafluoroethane
(HFC-125) are particularly preferable under consideration of the
fact that they less affect the ozone layer and global warming.
These HFCs may be used alone or two or more of them may be used in
combination.
[0063] HCFO is a compound having a carbon-carbon double bond, a
large proportion of halogen in the molecule, and a suppressed
combustibility. As HCFO, 1-chloro-2,3,3,3-tetrafluoropropene
(HCFO-1224yd), 1-chloro-2,2-difluoroethylene (HCFO-1122),
1,2-dichlorofluoroethylene (HCFO-1121), 1-chloro-2-fluoroethylene
(HCFO-1131), 2-chloro-3,3,3-trifluoropropene (HCFO-1233xf) and
1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) may be used. Among
these, HCFO-1224yd having particularly excellent performance is
preferable. In addition, HCFO-1233zd is preferable since it has a
high critical temperature, high durability and excellent
coefficient of performance. HCFOs other than HCFO-1224yd may be
used alone or two or more of these HCFOs may be used in
combination.
[0064] Operation of Bearing Part
[0065] When the swing piston type compressor (100) of the first
embodiment is operated, for example, under a high load or at a high
rpm, each of the elastic bearing portions (2) elastically deforms
when the drive shaft (140) is inclined as illustrated in FIG. 1. In
this way, a partial contact (line contact) between the drive shaft
(140) and the bearing portion (150) is less likely to occur,
resulting in suppression of rise in temperature. When the
oscillation piston type compressor (100) is restarted after
prolonged stop with lubricant dropping down from the bearing
portion (150), a partial contact occurs in a conventional
configuration before the lubricant is supplied to a sliding
portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in this first
embodiment, such intensive contact between the metals of the
corresponding parts can be avoided, thereby suppressing rise in
temperature.
[0066] Advantages of First Embodiment
[0067] According to this first embodiment, since the elastic
bearing portion (2) is provided as the heat generation suppression
portion (1) at a contact portion of the drive shaft (140) and the
bearing portion (150), when the swing piston type compressor (100)
is operated under a high load or at a high rpm, it is possible to
prevent a partial contact of the bearing portion (150) and
resulting rapid local rise in temperature. As a result, in the
swing piston type compressor (100) using a refrigerant prone to
disproportionation, through a simple configuration, it is possible
to suppress a partial contact of the bearing portion (150) and
resulting rise in temperature of the refrigerant, thereby
preventing the disproportional reaction of the refrigerant.
Further, even when lubricant in the bearing portion (150) drops
down in the swing piston type compressor (100) which has been
stopped for a long time, it is possible to prevent the
disproportional reaction at the time of restart of the
compressor.
[0068] Variations of First Embodiment
<First Variation>
[0069] As shown in FIG. 5 to FIG. 7, in a first variation of the
first embodiment, the elastic bearing portion (2) is applied to a
bearing structure of the swing piston type compressor (100) with
two cylinders.
[0070] As in the case with the first embodiment shown in FIG. 2 to
FIG. 4, this swing piston type compressor (100) includes a casing
(110), a compression mechanism (120) housed in the casing (110), an
electric motor (130) driving the compression mechanism (120), a
drive shaft (140) connecting the compression mechanism (120) and
the electric motor (130), and a bearing portion (150) rotatably
supporting the drive shaft (140).
[0071] The compression mechanism (120) is a configuration in which
a front head (122), a first cylinder (121A), a middle plate (124),
a second cylinder (121B), and a rear head (123) are fastened with
one another through a fastening member such as a bolt to be
integrally formed. A first piston (125A) is disposed in the first
cylinder (121A), while a second piston (125B) is disposed in the
second cylinder (121B).
[0072] The drive shaft (140) is fixed to the rotor (132) of the
electric motor (130), rotates integrally with the rotor (132) and
is provided with a first eccentric portion (141A) engaging with the
first piston (125A) and a second eccentric portion (141B) engaging
with the second piston (125B). This drive shaft (140) is rotatably
supported by the bearing portion (150) of the front head (122) and
the bearing portion (150) of the rear head (123).
[0073] As shown in FIG. 6, the first piston (125A) and the second
piston (125B) are configured in the same manner as the piston (125)
of the first embodiment. Specifically, the first piston (125A) is
provided with an annular portion (125Aa) and a blade (125Ab)
extending from the annular portion (125Aa) toward the outer
periphery, which are integrally formed. The blade (125Ab) is
supported by an oscillation bush (127A). The second piston (125B)
is provided with an annular portion (125Ba) and a blade (125Bb)
extending from the annular portion (125Ba) toward the outer
periphery, which are integrally formed. The blade (125Bb) is
supported by an oscillation bush (127B).
[0074] In this embodiment, the bearing portion (150) of the rear
head (123) is provided with an elastic bearing portion (2). As
shown in FIG. 7, the elastic bearing portion (2) is formed such
that a groove (123a) having an arc-like shape is formed in a part
of the rear head (123) viewed in a circumferential direction so
that the outer diameter of the bearing portion (150) of the rear
head (123) is smaller than that of the main body portion (1a) of
the bearing portion (150).
[0075] The groove having the arch-like shape as illustrated is an
arc of about 130.degree.. The range of the degrees of the arc is
not limited thereto. The groove may be, for example, a semicircle
of about 180.degree..
[0076] In the above configuration, in case where this swing piston
type compressor (100) is operated, for example, under a high load
or at a high rpm, the elastic bearing portion (2) elastically
deforms when the drive shaft (140) is inclined as illustrated in
FIG. 1. In this way, a partial contact (line contact) between the
drive shaft (140) and the bearing portion (150) is less likely to
occur, resulting in suppression of rise in temperature. When the
swing piston type compressor (100) is restarted after prolonged
stop in a state in which lubricant drops down from the bearing
portion (150), a partial contact occurs in a conventional
configuration before the lubricant is supplied to a sliding
portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in the first
variation of the first embodiment, such intensive contact between
the metals of the corresponding parts can be avoided, thereby
suppressing rise in temperature.
[0077] Therefore, even when the swing piston type compressor (100)
is operated under a high load or at a high rpm, it is possible to
prevent a partial contact of the bearing portion (150) and
resulting rapid local temperature rise As a result, in the swing
piston type compressor (100) using a refrigerant prone to
disproportionation, through a simple configuration, it is possible
to suppress a partial contact of the bearing portion (150) and
resulting rise in temperature of the refrigerant, thereby
preventing the disproportional reaction of the refrigerant.
[0078] <Second Variation>
[0079] As shown in FIG. 8, in a second variation of the first
embodiment, the elastic bearing portion (250) (elastic bearing
portion (2) of FIG. 1) is applied to a bearing structure of the
scroll compressor (200).
[0080] This scroll compressor (200) includes a casing (210), a
compression mechanism (220) housed in the casing (210), an electric
motor (230) located below the compression mechanism (220) and
driving the compression mechanism (220), a drive shaft (240)(S)
connecting the compression mechanism (220) and the electric motor,
and a bearing portion (250) (bearing portion (B) of FIG. 1)
rotatably supporting the drive shaft (240) (drive shaft (S) of FIG.
1).
[0081] The compression mechanism (220) is provided with a fixed
scroll (221) and a movable scroll (225). The fixed scroll (221) is
obtained by integrally forming a fixed end plate (222) and a fixed
lap (223). The movable scroll (225) is obtained by integrally
forming a movable end plate (226) and a movable lap (227). The
fixed lap (223) and the movable lap (227) are wall parts meshing
with each other and formed into a spiral shape. A compression
chamber is defined between the fixed lap (223) and the movable lap
(227).
[0082] A housing (260) is fixed on the casing (210). The fixed
scroll (221) is attached to the housing (260) through a fastening
member such as a bolt. The housing (260) constitutes the above
bearing portion (250) rotatably supporting the drive shaft (240)
whose eccentric portion (241) is connected to a boss portion (228)
formed on the movable scroll (225). The above boss portion (228)
also constitutes the bearing portion (250) rotatably supporting the
eccentric portion (241) of the drive shaft (240).
[0083] The bearing portion (250) of the housing (260) is provided
with a groove portion (250a) formed into a circular shape with its
outer diameter smaller than that of the main body portion (1a) of
the bearing portion (250). The inside of this groove portion (250a)
constitutes the elastic bearing portion (2). Also on a lower end of
the boss portion (228), there is provided a groove portion (228a)
formed into a circular shape. The elastic bearing portion (2) with
its outer diameter smaller than that of the main body portion (1a)
of the boss portion (228) (bearing portion (250)) is formed by this
groove portion (228a) formed into the circular shape.
[0084] As described above, in the second variation of the first
embodiment, the elastic bearing portions (2) are respectively
provided on the bearing portion (250) of the housing (260)
supporting a main shaft portion of the drive shaft (240) and on the
boss portion (228) (bearing portion (250)) of the movable scroll
(225) supporting the eccentric portion (241) of the drive shaft
(240).
[0085] In the above configuration, in case where the scroll
compressor (200) is operated, for example, under a high load or at
a high rpm, each of the elastic bearing portions (2) elastically
deforms when the drive shaft (240) is inclined as illustrated in
FIG. 1. In this way, a partial contact (line contact) between the
drive shaft (240) and the bearing portion (250) is less likely to
occur, resulting in suppression of rise in temperature. When the
scroll compressor (200) is restarted after prolonged stop in a
state in which lubricant drops down from the bearing portion (250),
a partial contact occurs in a conventional configuration before the
lubricant is supplied to a sliding portion, resulting in that
metals of corresponding parts intensively contact each other. On
the contrary, in the second variation of the first embodiment, such
intensive contact between the metals of the corresponding parts can
be avoided, thereby suppressing rise in temperature.
[0086] Therefore, even when the scroll compressor (200) is operated
under a high load or at a high rpm, it is possible to prevent a
partial contact of the bearing portion (250) and resulting rapid
local temperature rise As a result, in the scroll compressor (200)
using a refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (250) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0087] Second Embodiment
[0088] A second embodiment will be described.
[0089] In this second embodiment, the heat generation suppression
portion (1) is configured of a shaft side crowning portion (3)
shown in FIG. 9. As illustrated, in this configuration, the above
drive shaft (S) is provided with, on its engagement portion
engaging with the above bearing portion (B), the shaft side
crowning portion (3) with its outer diameter decreasing in
direction from a center portion toward an end edge portion of the
engagement portion.
[0090] As the refrigerant compressed by this compressor, the same
refrigerant as that used in the first embodiment is used.
[0091] As shown in FIG. 10, the compressor (10) of the second
embodiment is a scroll compressor (200). As in the case with the
second variation of the first embodiment, this scroll compressor
(200) includes a casing (210), a compression mechanism (220) housed
in the casing (210), an electric motor (230) located below the
compression mechanism (220) and driving the compression mechanism
(220), a drive shaft (240) (drive shaft (S) of FIG. 2) connecting
the compression mechanism (220) and the electric motor, and a
bearing portion (250) (bearing portion (B) of FIG. 2) rotatably
supporting the drive shaft (240).
[0092] The compression mechanism (220) is provided with a fixed
scroll (221) and a movable scroll (225). The fixed scroll (221) is
obtained by integrally forming a fixed end plate (222) and a fixed
lap (223). The movable scroll (225) is obtained by integrally
forming a movable end plate (226) and a movable lap (227). The
fixed lap (223) and the movable lap (227) are wall parts meshing
with each other and formed into a spiral shape. A compression
chamber is defined between the fixed lap (223) and the movable lap
(227).
[0093] A housing (260) is fixed on the casing (210). The fixed
scroll (221) is attached to the housing (260) through a fastening
member such as a bolt. The housing (260) constitutes the bearing
portion (250) rotatably supporting the drive shaft (240) whose
eccentric portion (241) is connected to a boss portion (228) formed
on the movable scroll (225). The above boss portion (228) also
constitutes the bearing portion (250) rotatably supporting the
eccentric portion (241) of the drive shaft (240).
[0094] A shaft side crowning portion (3) is formed on a main shaft
portion (242) of the drive shaft (240) supported by the bearing
portion (250) of the housing (260). The shaft side crowning portion
(3) is formed similarly on the eccentric portion (241) of the drive
shaft (240) supported by the boss portion (228).
[0095] As described above, in this second embodiment, the main
shaft portion (242) and the eccentric portion (241) of the drive
shaft (240) are each provided with the corresponding shaft side
crowning portion (3).
[0096] In the above configuration, when the scroll compressor (200)
is operated, for example, under a high load and at a high rpm, in
case of inclination of the drive shaft (240) shown in FIG. 9, each
of the shaft side crowning portions (3) receives the inclination of
the drive shaft (240). In this way, a partial contact (line
contact) between the drive shaft (240) and the bearing portion
(250) is less likely to occur, resulting in suppression of rise in
temperature. When the scroll compressor (200) is restarted after
prolonged stop in a state in which lubricant drops down from the
bearing portion (250), a partial contact occurs in a conventional
configuration before the lubricant is supplied to a sliding
portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in this second
embodiment, such intensive contact between the metals of the
corresponding parts can be avoided, thereby suppressing rise in
temperature.
[0097] Therefore, even when the scroll compressor (200) is operated
under a high load or at a high rpm, it is possible to prevent a
partial contact of the bearing portion (250) and resulting rapid
local temperature rise As a result, in the scroll compressor (200)
using a refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (250) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0098] Third Embodiment
[0099] The third embodiment will be described.
[0100] In this third embodiment, the heat generation suppression
portion (1) is configured by a bearing side crowning portion (4)
shown in FIG. 11. As illustrated, in the third embodiment, the
above bearing portion (B) is provided with, on its engagement
portion engaging with the above drive shaft (S), a bearing side
crowning portion (4) with its inner diameter increasing in
direction from a center portion toward an end edge portion of the
engagement portion.
[0101] As the refrigerant compressed by this compressor (10), the
same refrigerant as the first and the second embodiments is
used.
[0102] As shown in FIG. 12, in the third embodiment, the bearing
side crowning portion (4) is applied to the bearing structure of
the swing piston type compressor (100).
[0103] As in the case with the first embodiment shown in FIG. 2 to
FIG. 4, this swing piston type compressor (100) includes a casing
(110), a compression mechanism (120) housed in the casing (110), an
electric motor (130) driving the compression mechanism (120), a
drive shaft (140) connecting the compression mechanism (120) and
the electric motor (130), and a bearing portion (150) rotatably
supporting the drive shaft (140).
[0104] The compression mechanism (120) is a configuration in which
a front head (122), a cylinder (121), and a rear head (123) are
integrally fastened with each other through a fastening member such
as a bolt. A piston (125) is attached in the cylinder (121).
[0105] The drive shaft (140) is fixed to the rotor (132) of the
electric motor (130), rotates integrally with the rotor (132) and
is provided with an eccentric portion (141) engaging with the
piston (125). This drive shaft (140) is rotatably supported by the
bearing portion (150) of the front head (122) and the bearing
portion (150) of the rear head (123).
[0106] In this third embodiment, the bearing portion (150) of the
front head (122) and the bearing portion (150) of the rear head
(123) are each provided with a bearing side crowning portion (4).
These bearing side crowning portions (4) are portions formed as a
curved surface or a tapered surface on engagement portions engaging
with the above drive shaft (140) in the respective bearing portions
(150) of the front head (122) and the rear head (123) such that the
inner diameter of each of the bearing side crowning portion (4)
increases in direction from a center portion toward the end edge
portion of the corresponding engagement portion.
[0107] In the above configuration, when this swing piston type
compressor (100) is operated, for example, under a high load or at
a high rpm, in case of inclination of the drive shaft (140) shown
in FIG. 11, the bearing side crowning portion (4) receives the
inclination of the drive shaft (140). Thus, conventionally, there
arises a partial contact as outlined by the broken line of FIG. 13.
On the contrary, according to this embodiment, a partial contact
(line contact) between the drive shaft (140) and the bearing
portion (150) is less likely to occur, resulting in suppressing
rise in temperature. When the swing piston type compressor (100) is
restarted after prolonged stop in a state in which lubricant drops
down from the bearing portion (150), a partial contact occurs in a
conventional configuration before the lubricant is supplied to a
sliding portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in this third
embodiment, such intensive contact between the metals of the
corresponding parts can be avoided, thereby suppressing rise in
temperature.
[0108] Therefore, even when the swing piston type compressor (100)
is operated under a high load or at a high rpm, it is possible to
prevent a partial contact of the bearing portion (150) and
resulting rapid local temperature rise As a result, in the
oscillation piston type compressor (100) using a refrigerant prone
to disproportionation, through a simple configuration, it is
possible to suppress a partial contact of the bearing portion (150)
and resulting rise in temperature of the refrigerant, thereby
preventing the disproportional reaction of the refrigerant.
[0109] Fourth Embodiment
[0110] The fourth embodiment will be described.
[0111] In this fourth embodiment, the heat generation suppression
portion (1) is configured by a bearing side oil groove portion (5)
shown in FIG. 14. As illustrated, in this fourth embodiment, the
end edge portion of the bearing portion (B) is provided with the
bearing side oil groove portion (5) with its inner diameter larger
than that of the main body except for the above end edge portion so
as to store lubricant.
[0112] As the refrigerant compressed by the compressor (10), the
same refrigerant as the first to the third embodiments is used.
[0113] As shown in FIG. 15, in the fourth embodiment, the bearing
side oil groove portion (5) is applied to a bearing structure of a
reciprocation type compressor (300).
[0114] This reciprocation type compressor (300) includes a casing
(310), a compression mechanism (320) of reciprocation type with
four cylinders housed in the casing (310), an electric motor (330)
driving the compression mechanism (320), a crankshaft (340) (drive
shaft (S) of FIG. 14) connecting the compression mechanism (320)
and the electric motor (330), and a bearing portion (350) (bearing
portion (B) of FIG. 14) rotatably supporting the drive shaft
(340).
[0115] The compression mechanism (320) is provided with a cylinder
head (321) including four cylinder chambers arranged at, for
example, 90.degree. angular intervals in plan view, and a piston
(322) reciprocating in each of the cylinder chambers. Each of the
pistons (322) is connected to a corresponding piston rod (323). A
crankshaft (340) (drive shaft (S)) is connected to the piston rod
(323). Each of the pistons (322) reciprocates at a predetermined
time point in the corresponding cylinder chamber, thereby
compressing the refrigerant.
[0116] The crankshaft (340) is connected to the electric motor
(330) located above the compression mechanism (320) and integrally
rotates with the rotor (332) of the electric motor (330). The
crankshaft (340) is rotatably supported by the bearing portion
(350) which is integrally formed with the cylinder head (321) and
has a tubular shape.
[0117] In this fourth embodiment, a bearing side oil groove portion
(5) is formed on the bearing portion (350). This bearing side oil
groove portion (5) is provided to the end of the bearing portion
(350) such that the inner diameter of the bearing side oil groove
portion (5) has the inner diameter larger than that of the main
body portion (1) of the bearing portion (350) so as to store
lubricant. Although not explained in detail, the lubricant is
supplied from the cylinder head (321) to this bearing side oil
groove portion (5).
[0118] In the above configuration, when the reciprocation type
compressor (300) is operated, for example, under a high load and at
a high rpm, in case of inclination of the drive shaft (340), the
lubricant stored in the bearing side oil groove portion (5) is
supplied between the drive shaft (340) and the bearing portion
(350) so that an oil coating sufficient for prevention of seizing
is formed. As a result, the drive shaft (340) and the bearing
portion (350) come into surface-to-surface contact with each other
with the oil coating provided therebetween. In this way, a partial
contact between the drive shaft (340) (S) and the bearing portion
(350) is less likely to occur, resulting in suppression of rise in
temperature. When the reciprocation type compressor (300) is
restarted after prolonged stop, a partial contact occurs in a
conventional configuration before lubricant is supplied to a
sliding portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in this fourth
embodiment, such intensive contact between the metals of the
corresponding parts can be avoided, since the oil is stored in the
bearing side oil groove portion (5), thereby suppressing rise in
temperature.
[0119] Therefore, even when the reciprocation type compressor (300)
is operated under a high load or at a high rpm, it is possible to
prevent rapid local temperature rise in the bearing portion (350).
As a result, in the reciprocation type compressor (300) using a
refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (350) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0120] Fifth Embodiment
[0121] The fifth embodiment will be described.
[0122] In this fifth embodiment, the heat generation suppression
portion (1) is configured by a shaft side oil groove portion (6)
shown in FIG. 14. As illustrated, in the fifth embodiment, the
above drive shaft (S) is provided with, on a part of its engagement
portion engaging with the above bearing portion (B), the shaft side
oil groove portion (6) storing lubricant.
[0123] As the refrigerant compressed by the compressor (10), the
same refrigerant as the first to the fourth embodiments is
used.
[0124] In the fifth embodiment, the shaft side oil groove portion
(6) is applied to the scroll compressor (200).
[0125] The basic configuration of this scroll compressor (200) is
identical to that of the scroll compressors (200) of the second
variation of the first embodiment and of the second embodiment. The
compression mechanism (220) is provided with a fixed scroll (221)
and a movable scroll (225). The boss portion (228) (bearing portion
(250)) of the movable scroll (225) supports the eccentric portion
(241) of the drive shaft (240). A main shaft portion (242) of the
drive shaft (240) is rotatably supported by the housing (260) to
which the fixed scroll (221) is fixed through a fastening member
such as a bolt. Since the configuration of each of the parts is
common to the second variation of the first embodiment and of the
second embodiment except for the shaft side oil groove portion (6),
a detailed description thereof will thus be omitted.
[0126] In this scroll compressor (200), the eccentric portion (241)
of the drive shaft (240) is provided with an oil sump (245) having
an annular space extending from the upper end face of the eccentric
portion (241) to the position slightly above the lower end of the
eccentric portion (241). The eccentric portion (241) of the drive
shaft (240) is provided with the shaft side oil groove portion (6)
communicating with this oil sump (245) and opening to an outer
peripheral surface of the eccentric portion (241).
[0127] This shaft side oil groove portion (6) is configured such
that a part of the engagement portion thereof engaging with the
boss portion (228) (bearing portion (250)) stores the lubricant.
Specifically, the shaft side oil groove portion (6) is constituted
by a communication hole as illustrated in FIG. 16. Alternatively,
as shown in FIG. 14, the shaft side oil groove portion (6) is
configured to have a groove such that a part of the engagement
portion of the drive shaft (240) engaging with the bearing portion
(250) is provided with a groove with its outer diameter smaller
than that of the main body portion except for the above part so
that oil is stored in this groove.
[0128] In the above configuration, when this scroll compressor
(200) is operated under a high load or at a high rpm, in case of
inclination of the drive shaft (240), the lubricant stored in the
shaft side oil groove portion (6) is supplied between the eccentric
portion (241) of the drive shaft (240) and the boss portion (228)
(bearing portion (250)) so that an oil coating sufficient for
prevention of seizing is formed. As a result, the eccentric part
(241) of the drive shaft (240) and the boss portion (228) come into
surface-to-surface contact with each other with the oil coating
provided therebetween. In this way, a partial contact between the
eccentric portion (241) of the drive shaft (240) and the boss
portion (228) is less likely to occur, resulting in suppression of
rise in temperature. When the scroll compressor (200) is restarted
after prolonged stop, a partial contact occurs in a conventional
configuration before the lubricant is supplied to a sliding
portion, resulting in that metals of corresponding parts
intensively contact each other. On the contrary, in this fifth
embodiment, such intensive contact between the metals of the
corresponding parts can be avoided, since oil is stored in the
shaft side oil groove portion (6), thereby suppressing rise in
temperature.
[0129] Therefore, even when the scroll compressor (200) is operated
under a high load or at a high rpm, it is possible to prevent
resulting rapid local temperature rise of the bearing portion
(250). As a result, in the scroll compressor (200) using a
refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (250) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0130] Variation of Fifth Embodiment
[0131] <First Variation>
[0132] As shown in FIG. 17, in the first variation of the fifth
embodiment, the shaft side oil groove portion (6) of the scroll
compressor (200) supplies lubricant between the main shaft portion
of the drive shaft (240) and the bearing portion (250) of the
housing (260). The scroll compressor (200) in the first variation
is different in detail from that in the fifth embodiment of FIG.
16. However, they are identical to each other in basic
configuration. Hence, a detailed description of the above scroll
compressor will be omitted.
[0133] In this first variation of the fifth embodiment, an upper
end face of the drive shaft (240)(S) is provided with an oil sump
(246) having a circular cross section and extending from the upper
end face of the eccentric portion (241) over the lower end of the
eccentric portion (241) and reaching the main shaft portion. The
main shaft portion of the drive shaft (240) is provided with a
shaft side oil groove portion (6) communicating with this oil sump
(246) and opening to an outer peripheral surface of the main shaft
portion (242).
[0134] This shaft side oil groove portion (6) is configured such
that a part of the engagement portion thereof engaging with the
bearing portion (250) of the housing (260) stores the
lubricant.
[0135] In the above configuration, when this scroll compressor
(200) is operated under a high load or at a high rpm, in case of
inclination of the drive shaft (240) (S), the lubricant stored in
the shaft side oil groove portion (6) is supplied between the main
shaft portion of the drive shaft (240) and the bearing portion
(250) so that an oil coating sufficient for prevention of seizing
is formed. As a result, the main shaft portion of the drive shaft
(240) and bearing portion (250) come into surface-to-surface
contact with each other with the oil coating provided therebetween.
In this way, a partial contact between the main shaft portion of
the drive shaft (240) and the bearing portion (250) is less likely
to occur, resulting in suppression of rise in temperature. When the
scroll compressor (200) is restarted after prolonged stop, a
partial contact occurs in a conventional configuration before
lubricant is supplied to a sliding portion, resulting in that
metals of corresponding parts intensively contact each other. On
the contrary, in this first variation of the fifth embodiment, such
intensive contact between the metals of the corresponding parts can
be avoided, since the oil is stored in the shaft side oil groove
portion (6), thereby suppressing rise in temperature.
[0136] Therefore, even when the scroll compressor (200) is operated
under a high load or at a high rpm, it is possible to prevent
resulting rapid local temperature rise of the bearing portion
(250). As a result, in the scroll compressor (200) using a
refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (250) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0137] <Second Variation>As shown in FIG. 18, in the second
variation of the fifth embodiment, the shaft side oil groove
portion (6) of the scroll compressor (200) supplies lubricant to a
sliding portion between the eccentric portion (241) of the drive
shaft (240)(S) and the bearing portion (250). In this scroll
compressor (200), the upper end of the drive shaft (240) is
provided with an eccentric portion (241) with a diameter larger
than that of the main shaft portion (242). An eccentric hole (243)
formed in the eccentric portion (241) rotatably supports a pin
shaft (229) of the movable scroll (225). The eccentric portion
(241) of the drive shaft (240) is rotatably supported by the
bearing portion (250).
[0138] The eccentric hole (243) formed to support the pin shaft on
the upper end of the drive shaft (240) is a hole whose bottom
surface is located at a position lower than an tip (lower end) of
the pin shaft. This eccentric hole (243) constitutes an oil sump.
The part with larger diameter is provided with a shaft side oil
groove portion (6) communicating with this oil sump and opening to
an outer peripheral surface of the eccentric portion (241).
[0139] This shaft side oil groove portion (6) is configured such
that a part of the engagement portion thereof engaging with the
bearing portion (250) of the housing (260) stores lubricant.
[0140] In the above configuration, when this compressor is operated
under a high load or at a high rpm, in case of inclination of the
drive shaft (240), the lubricant stored in the shaft side oil
groove portion (6) is supplied between the eccentric portion (241)
of the drive shaft (240) and the bearing portion (250) so that an
oil coating sufficient for prevention of seizing is formed. As a
result, the eccentric portion (241) of the drive shaft (240) and
the bearing portion (250) come into surface-to-surface contact with
each other with the oil coating provided therebetween. In this way,
a partial contact between the eccentric portion (241) of the drive
shaft (240) and the bearing portion (250) is less likely to occur,
resulting in suppression of rise in temperature. When the scroll
compressor (200) is restarted after prolonged stop, a partial
contact occurs in a conventional configuration before lubricant is
supplied to a sliding portion, resulting in that metals of
corresponding parts intensively contact each other. On the
contrary, in this second variation of the fifth embodiment, such
intensive contact between the metals of the corresponding parts can
be avoided, since the oil is stored in the shaft side oil groove
portion (6), thereby suppressing rise in temperature.
[0141] Therefore, even when the scroll compressor (200) is operated
under a high load or at a high rpm, it is possible to prevent
resulting rapid local temperature rise of the bearing portion
(250). As a result, in the scroll compressor (200) using a
refrigerant prone to disproportionation, through a simple
configuration, it is possible to suppress a partial contact of the
bearing portion (250) and resulting rise in temperature of the
refrigerant, thereby preventing the disproportional reaction of the
refrigerant.
[0142] Another Embodiment
[0143] The above-described embodiments may be modified as
follows.
[0144] The above embodiments include examples for applying the
bearing structure of the present disclosure to the swing piston
type compressor, the scroll type compressor and the reciprocation
type compressor. This bearing structure may also be applied to
other types of compressors such as a rolling piston type
compressor.
[0145] Note that the foregoing description of the embodiments is a
merely preferred example in nature, and is not intended to limit
the scope, application, or uses of the present disclosure.
INDUSTRIAL APPLICABILITY
[0146] As described above, the present disclosure is useful in a
compressor compressing a refrigerant including hydrocarbon fluoride
prone to disproportionation where heat generation is suppressed to
prevent disproportional reaction.
DESCRIPTION OF REFERENCE CHARACTERS
[0147] 1 Heat Generation Suppression Portion
[0148] 2 Elastic Bearing Portion
[0149] 3 Shaft Side Crowning Portion
[0150] 4 Bearing Side Crowning Portion
[0151] 5 Bearing Side Oil Groove Portion
[0152] 6 Shaft Side Oil Groove Portion
[0153] 10 Compressor
[0154] 11 Casing
[0155] 12 Compression Mechanism
[0156] 13 Electric Motor
[0157] B Bearing Portion
[0158] S Drive Shaft
* * * * *