U.S. patent application number 10/229422 was filed with the patent office on 2003-03-06 for sealing mechanism for compressor.
Invention is credited to Shintoku, Noriyuki, Shirai, Kuniyoshi.
Application Number | 20030044294 10/229422 |
Document ID | / |
Family ID | 19085542 |
Filed Date | 2003-03-06 |
United States Patent
Application |
20030044294 |
Kind Code |
A1 |
Shintoku, Noriyuki ; et
al. |
March 6, 2003 |
Sealing mechanism for compressor
Abstract
A sealing mechanism is used for a compressor. The compressor has
a housing, a valve plate assembly located in the housing. The
housing has a cylinder block and a cylinder head. The cylinder
block and the cylinder head are connected with each other. The
valve plate assembly has a plurality of plates. The sealing
mechanism has a seal portion. The seal portion is a peripheral
portion of one of the plates that extends radially outward in the
compressor relative to the other plates. The seal portion seals a
peripheral section between the cylinder block and the cylinder
head. This provides an inexpensive and simple sealing mechanism of
the compressor.
Inventors: |
Shintoku, Noriyuki;
(Kariya-shi, JP) ; Shirai, Kuniyoshi; (Kariya-shi,
JP) |
Correspondence
Address: |
MORGAN & FINNEGAN, L.L.P.
345 Park Avenue
New York
NY
10154
US
|
Family ID: |
19085542 |
Appl. No.: |
10/229422 |
Filed: |
August 27, 2002 |
Current U.S.
Class: |
417/569 ;
417/571 |
Current CPC
Class: |
F04B 27/1081
20130101 |
Class at
Publication: |
417/569 ;
417/571 |
International
Class: |
F04B 039/10 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 28, 2001 |
JP |
2001-257949 |
Claims
1. A sealing mechanism for a compressor, wherein the compressor has
a housing, a valve plate assembly located in the housing, wherein
the housing has a cylinder block and a cylinder head, wherein the
cylinder block and the cylinder head are connected with each other,
wherein the valve plate assembly has a plurality of plates, the
sealing mechanism comprising: a seal portion, wherein the seal
portion is a peripheral portion of one of the plates that extends
radially outward in the compressor relative to the other plates,
and wherein the seal portion seals a peripheral section between the
cylinder block and the cylinder head.
2. The sealing mechanism according to claim 1, wherein the cylinder
block has a cylinder bore, wherein the valve plate assembly has a
first plate, a main plate, and a second plate, wherein the first
plate has a suction valve flap, which is opened when gas is drawn
in the cylinder bore, wherein the main plate has a suction port and
a discharge port to permit the gas to pass there through, and
wherein the second plate has a discharge valve flap, which is
opened when the gas is discharged from the cylinder bore.
3. The sealing mechanism according to claim 2, wherein the valve
plate assembly has a retainer plate, which restricts the opening of
the discharge valve flap.
4. The sealing mechanism according to claim 2, wherein the seal
portion is located in one of the first plate and the second
plate.
5. The sealing mechanism according to claim 3, wherein the seal
portion is located in the retainer plate.
6. The sealing mechanism according to claim 1, wherein the seal
portion is formed by coating at least part of the peripheral
surface of one of the plates with seal material.
7. The sealing mechanism according to claim 6, wherein the seal
material is coated substantially on the entire surface of the one
of the plates.
8. The sealing mechanism according to claim 1, wherein the
compressor is double-headed piston type compressor.
9. A compressor comprising: a cylinder block; a cylinder head
connected to the cylinder block; and a valve plate assembly located
between the cylinder block and the cylinder head, wherein the valve
plate assembly has a plurality of plates, wherein a peripheral
portion of one of the plates that extends radially outward in the
compressor relative to the other plates is a seal portion, and
wherein the seal portion seals a peripheral section between the
cylinder block and the cylinder head.
10. The compressor according to claim 9, wherein the cylinder block
has a cylinder bore, wherein the valve plate assembly has a first
plate, a main plate, and a second plate, wherein the first plate
has a suction valve flap, which is opened when gas is drawn in the
cylinder bore, wherein the main plate has a suction port and a
discharge port to permit the gas to pass there through, and wherein
the second plate has a discharge valve flap, which is opened when
the gas is discharged from the cylinder bore.
11. The compressor according to claim 10, wherein the valve plate
assembly has a retainer plate, which restricts the opening of the
discharge valve flap.
12. The compressor according to claim 10, wherein the seal portion
is located in one of the first plate and the second plate.
13. The compressor according to claim 11, wherein the seal portion
is located in the retainer plate.
14. The compressor according to claim 9, wherein the seal portion
is formed by coating at least part of the peripheral surface of one
of the plates with seal material.
15. The compressor according to claim 14, wherein the seal material
is coated substantially on the entire surface of the one of the
plates.
16. The compressor according to claim 9, wherein the compressor is
double-headed piston type compressor.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a compressor having a valve
plate assembly located in a housing, which includes a cylinder
block and a cylinder head. Particularly, the present invention
pertains to a sealing mechanism between adjoining sections of the
cylinder block and the cylinder head.
[0002] Japanese Laid-Open Utility Model Publication No. 56-113186
(prior art (1)) discloses a sealing mechanism including a gasket.
The gasket is fitted to a valve plate assembly. The diameter of the
gasket is greater than the diameter of any valve plate in the valve
plate assembly. The outer portion of the gasket protrudes from the
valve plate assembly. The protruding portion is located between the
adjoining sections of the cylinder block and the cylinder head. The
protruding portion seals the adjoining sections of the cylinder
block and the cylinder head.
[0003] Japanese Laid-Open Patent Publication No. 10-176669 (prior
art (2)) discloses another sealing mechanism. In this structure,
the outer portion of a valve plate assembly is located between a
cylinder block and a cylinder head. The valve plate assembly
includes a first plate and a second plate. Rubber coating is formed
on both end surfaces of the first and second plates. The first
plate seals the adjoining sections of the cylinder block and the
valve plate assembly. The second plate seals the adjoining sections
of the valve plate assembly and the cylinder head.
[0004] The sealing mechanism of prior art (1) requires a dedicated
gasket (plate) for sealing the adjoining sections of the cylinder
block and the cylinder head, which increases the number of parts in
the compressor. The gasket also increases the thickness of the
group of plates located between the cylinder block and the cylinder
head, which increases the axial size of the compressor.
[0005] In the sealing mechanism of prior art (2), the rubber
coating needs to be formed on both end surfaces of the first and
second plates. The cost of the sealing mechanism is thus
increased.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an objective of the present invention to
provide an inexpensive and simple sealing mechanism of a
compressor.
[0007] To achieve the above objective, the present invention
provides a sealing mechanism for a compressor. The compressor has a
housing and a valve plate assembly. The valve plate assembly is
located in the housing. The housing has a cylinder block and a
cylinder head. The cylinder block and the cylinder head are
connected with each other. The valve plate assembly has a plurality
of plates. The sealing mechanism has a seal portion. The seal
portion is a peripheral portion of one of the plates that extends
radially outward in the compressor relative to the other plates.
The seal portion seals a peripheral section between the cylinder
block and the cylinder head.
[0008] Other aspects and advantages of the invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0010] FIG. 1 is a cross-sectional view illustrating a
double-headed piston type variable displacement compressor
according to a preferred embodiment of the present invention;
[0011] FIG. 2 is an enlarged cross-sectional view showing a part
surrounded by a circle of a broken line in FIG. 1;
[0012] FIG. 3 is an enlarged cross-sectional view illustrating a
compressor according to another embodiment;
[0013] FIG. 4 is an enlarged cross-sectional view illustrating a
compressor according to another embodiment; and
[0014] FIG. 5 is an enlarged cross-sectional view illustrating a
compressor according to another embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0015] A double-headed piston swash plate type compressor according
to a preferred embodiment of the present invention will be
described with reference to FIGS. 1 and 2. The compressor forms
part of a refrigeration cycle of a vehicular air conditioning
system.
[0016] As shown in FIG. 1, the swash plate type compressor includes
a front cylinder block 11, a rear cylinder block 12, a front
cylinder head 13, and a rear cylinder head 14. The front cylinder
block 11 and the rear cylinder block 12 are adjacent to each other.
The left end of the compressor in FIG. 1 is defined as the front of
the compressor, and the right end is defined as the rear of the
compressor.
[0017] The front cylinder head 13 is secured to the front end face
of the front cylinder block 11 with a front valve plate assembly 15
in between. The rear cylinder head 14 is secured to the rear end
face of the rear cylinder block 12 with a rear valve plate assembly
16 in between. The front cylinder block 11, the rear cylinder block
12, the front cylinder head 13, the rear cylinder head 14 are
fastened together with bolts 17 (only one is shown) and form the
housing of the compressor.
[0018] A bearing 18 is located in the front cylinder block 11. A
bearing 19 is located in the rear cylinder block 12. The bearings
18, 19 rotatably support a drive shaft 20, which extends through
the cylinder blocks 11, 12. The drive shaft 20 is coupled to an
external drive source, which is a vehicle engine (not shown) in
this embodiment. The drive shaft 20 is rotated by power supplied by
the engine.
[0019] First cylinder bores 11a (only one is shown in FIG. 1) are
formed in the front cylinder block 11. The first cylinder bores 11a
surround the drive shaft 20. Second cylinder bores 12a (only one is
shown in FIG. 1) are formed in the rear cylinder block 12. The
second cylinder bores 12a surround the drive shaft 20. Each first
cylinder bore 11a and one of the second cylinder bores 12a are
aligned along an axis parallel to the drive shaft 20 and forms a
pair. The compressor has several pairs of the cylinder bores 11a,
12a (only one is shown in FIG. 1).
[0020] Each pair of the cylinder bores 11a, 12a accommodates a
double-headed piston 21. Each piston 21 has two cylindrical heads
21a. The end face of each head 21a of each piston 21 and the
corresponding one of the valve plate assemblies 15, 16 define a
compression chamber 22.
[0021] The front cylinder block 11 and the rear cylinder block 12
define a crank chamber 23 in between. A drive plate, which is a
swash plate 24 in this embodiment, is coupled to the drive shaft 20
and is located in the crank chamber 23. The swash plate 24 rotates
integrally with the drive shaft 20. Each piston 21 has a pair of
shoes 25 at an axial center, and is coupled to the peripheral
portion of the swash plate 24 with the shoes 25. Rotation of the
drive shaft 20 is converted into reciprocation of the pistons 21 by
the swash plate 24 and the shoes 25.
[0022] A dividing wall 13a projects from the inner surface of the
front cylinder head 13 toward the front valve plate assembly 15. A
dividing wall 14a projects from the inner surface of the rear
cylinder head 14 toward the rear valve plate assembly 16. The
distal end of the dividing wall 13a contacts the front valve plate
assembly 15, which defines a suction chamber 26 and a discharge
chamber 27 in the front cylinder head 13. The discharge chamber 27
is located about the suction chamber 26. The distal end of the
dividing wall 14a contacts the rear valve plate assembly 16, which
defines a suction chamber 26 and a discharge chamber 27 in the rear
cylinder head 14. The discharge chamber 27 is located about the
suction chamber 26.
[0023] Each valve plate assembly 15, 16 includes suction ports 28
and suction valve flaps 30 for closing the suction ports 28. Each
valve plate assembly 15, 16 also includes discharge ports 29 and
discharge valve flaps 31 for closing the discharge ports 29.
Further, each valve plate assembly 15, 16 includes a retainer 32.
When opened, the discharge valve flaps 31 contact the retainer 32,
which defines the maximum opening degree of the discharge valve
flaps 31.
[0024] Refrigerant gas is drawn into each suction chamber 26 from
an external refrigerant circuit (not shown). As each piston 21
moves from the top dead center position to the bottom dead center
position in relation to one of the suction chambers 26, the
refrigerant is drawn into the corresponding compression chamber 22
through the corresponding suction port 28 while flexing the suction
valve flap 30. When each piston 21 moves from the bottom dead
center position to the top dead center position in relation to one
of the discharge chambers 27, refrigerant in the corresponding
compression chamber 22 is compressed to a certain pressure. The
compressed gas is then discharged to the discharge chamber 27
through the corresponding discharge port 29 while flexing the
discharge valve flap 31. The discharged gas is supplied to the
external refrigerant circuit from the discharge chamber 27.
[0025] The structure of the valve plate assemblies 15, 16 and the
sealing mechanism of the compressor using the valve plate
assemblies 15, 16 will now be described. Since the front valve
plate assembly 15 has the same structure as that of the rear valve
plate assembly 16, only the explanation of the rear valve plate
assembly 16 will be given, and the explanation of the front valve
plate assembly 15 will be omitted.
[0026] FIG. 2 is an enlarged image of a portion encircled by broken
line in FIG. 1. As shown in FIG. 2, the valve plate assembly 16
includes a main plate 41, a first plate 42 located between the main
plate 41 and the rear cylinder block 12, a second plate 43 located
between the main plate 41 and the rear cylinder head 14, and a
retainer plate 44 located between the second plate 43 and the rear
cylinder head 14.
[0027] The main plate 41 is made of, for example, a metal such as
SPCC. The suction ports 28 and the discharge ports 29 are formed in
the main plate 41. The first plate 42 is made of, for example, a
metal such as hardened carbon steel. The suction valve flaps 30,
which are reed valves, are integrally formed with the first plate
42. The second plate 43 is made of, for example, a metal such as
stainless steel. The discharge valve flaps 31, which are reed
valves, are integrally formed with the second plate 43. The
retainer plate 44 is made of, for example, a metal such as SPCC.
The retainers 32 are integrally formed with the retainer plate 44.
The retainers 32 bulge into the discharge chamber 27.
[0028] A rubber layer 46 is formed between the retainer plate 44
and the rear cylinder head 14. The distal end of the dividing wall
14a contacts the retainer plate 44. Accordingly, the rubber layer
46 seals the suction chamber 26 and the discharge chamber 27 from
each other.
[0029] A rubber layer 47 is formed on each of the front end face
and the rear end face of the first plate 42. That is, the first
plate 42 has sealing function with rubber coatings and thus
functions as a gasket. The peripheral portion of the first plate 42
is extended outward compared to the plates 41, 43, 44 in the radial
direction of the compressor. The projecting peripheral portion
forms an annular rim. The rim and the corresponding portions of the
rubber layers 47 form a seal portion 45. The seal portion 45 is
located between the adjoining peripheral sections of the rear
cylinder block 12 and the rear cylinder head 14 and seals the
adjoining peripheral sections.
[0030] Like the rear valve plate assembly 16, the front valve plate
assembly 15 has a first plate 42 with a seal portion 45. The seal
portion 45 seals the adjoining peripheral sections of the front
cylinder block 11 and the front cylinder head 13.
[0031] The embodiment of FIGS. 1 and 2 provides the following
advantages.
[0032] (1) The adjoining peripheral sections of the peripheral
portions of each cylinder block 11, 12 and the corresponding
cylinder head 13, 14 is sealed by the rubber coated first plate 42.
Therefore, no dedicated sealing plate is required, and the number
of parts in the compressor is reduced. Also, the embodiment of the
FIGS. 1 and 2 reduces the thickness of the group of plates between
each cylinder block 11, 12 and the corresponding cylinder head 13,
14. This reduces the size of the compressor along the axis of the
drive shaft 20.
[0033] (2) The peripheral portion of each first plate 42 radially
protrudes outward in relation to the other plates 41, 43, 44 in the
associated valve plate assembly 15, 16. That is, only the first
plate 42 is located between the peripheral portions of each pair of
the cylinder block 11, 12 and the cylinder head 13, 14. Therefore,
to seal the adjoining peripheral sections of each cylinder block
11, 12 and the corresponding cylinder head 13, 14, only the first
plate 42 needs to be coated with rubber, which reduces the cost of
the sealing mechanism.
[0034] (3) Since reed valves (the suction valves 30) are integrally
formed with each first plate 42, the first plates 42 are more
likely to elastically deform compared to the main plates 41. That
is, the first plates 42 are made of thinner or more flexible
material. Therefore, the seal portion 45 of each first plate 42 is
elastically deformed to compensate for machining errors in the
peripheral portions of the corresponding cylinder block 11, 12 and
the corresponding cylinder head 13, 14. Accordingly, the sealing
property between the peripherally portions is improved.
[0035] (4) The sealing mechanism of the embodiment shown in FIGS. 1
and 2 is used in the double-head piston type compressor. The
double-headed piston type compressor has two sets of adjoining
peripheral sections of the cylinder blocks 11, 12 and the cylinder
heads 13, 14. The compressor also has the two valve plate
assemblies 15, 16. Therefore, the advantages (1) and (2) are
obtained at the front and rear sections of the compressor. In other
words, double-headed piston type compressors are particularly
favorable for applying the sealing mechanism of the present
invention.
[0036] It should be apparent to those skilled in the art that the
present invention may be embodied in many other specific forms
without departing from the spirit or scope of the invention.
Particularly, it should be understood that the invention may be
embodied in the following forms.
[0037] As shown in modified embodiments of FIGS. 3 to 5, the rubber
layers 47 may be formed on both sides of any one of the plates 41,
43, 44 other than the first plate 42. The peripheral portion of the
one of the plates 41, 43, 44 on which the rubber layers 47 are
formed is radially extended outward than the other plates 41 to 44.
The projected portion functions as the seal portion 45. The seal
portion 45 in each of the embodiments of FIGS. 3 to 5 is located
between each cylinder block 11, 12 and the corresponding cylinder
head 13, 14.
[0038] In FIG. 3, the main plate 41 seals the adjoining peripheral
sections of each cylinder block 11, 12 and the corresponding
cylinder head 13, 14. In FIG. 4, the second plate 43 seals the
adjoining peripheral sections of each cylinder block 11, 12 and the
corresponding cylinder head 13, 14. In FIG. 5, the retainer plate
44 seals the adjoining peripheral sections of each cylinder block
11, 12 and the corresponding cylinder head 13, 14. Particularly, in
the embodiment of FIG. 4, the adjoining peripheral sections of each
cylinder block 11, 12 and the cylinder head 13, 14 are effectively
sealed for the reason mentioned in the advantage (3) of the
embodiment shown in FIG. 2. In the embodiment of FIG. 5, the rubber
layers 47 are formed only on both sides of the retainer plate 44.
The rubber layers 47 seal the adjoining peripheral sections of each
cylinder block 11, 12 and the corresponding cylinder head 13, 14.
The rubber layers 47 also seal the suction chamber 26 and the
discharge chamber 27 from each other. Therefore, the embodiment of
FIG. 5 further reduces the cost of the sealing mechanism.
[0039] In the embodiments of FIGS. 1 to 5, the rubber layers 47 may
be formed only on the seal portion 45. This reduces the amount of
rubber used in the compressor. However, forming rubber layers on
the entire end faces of the plates 41 to 44 as illustrated in FIGS.
1 to 5 is easier than forming rubber layers on part (peripheral
portion) of the plates 41 to 44. Forming rubber layers on the
entire end faces of the plates 41 to 44 eliminates spaces between
each adjacent pair of the plates 41 to 44 and stabilizes the plates
41 to 44.
[0040] The sealing material is not limited to rubber. However,
resin or soft metal may be used.
[0041] Each retainer 32 need not be located in the corresponding
valve plate assembly 15, 16. For example, the maximum opening
degree of each discharge valve flap 31 may be defined by contact
between the discharge valve flaps 31 and the inner wall of the
corresponding cylinder head 13, 14. In this case, the retainer
plates 44 may be omitted and the structure of the valve plate
assemblies 15, 16 is simplified. In this modification, the dividing
wall 13a, 14a of each cylinder head 13, 14 contacts the
corresponding second plate 43. If the retainer plates 44 are
omitted from the embodiments of FIGS. 2 and 3, a rubber coating is
formed on the end face of each second plate 43 that faces the
corresponding cylinder head 13, 14 to seal the suction chamber 26
and the discharge chamber 27 from each other.
[0042] The adjoining peripheral sections of the front cylinder
block 11 and the front cylinder head 13 may be sealed by a
different one of the plates 41 to 44 from the plate that seals the
adjoining peripheral sections of the rear cylinder block 12 and the
rear cylinder head 14. For example, the peripheral adjoining
sections of the front cylinder block 11 and the front cylinder head
13 may be sealed by the first plate 42 of the front valve plate
assembly 15, and the peripheral adjoining sections of the rear
cylinder block 12 and the rear cylinder head 14 may be sealed by
the second plate 43 of the rear valve plate assembly 16.
[0043] The present invention may be embodied in the sealing
mechanism of a single-headed piston type compressor.
[0044] The present invention may be embodied in the sealing
mechanism of a wobble plate type compressor.
[0045] The present invention may be embodied in the sealing
mechanism of a wave cam type compressor having a wave cam instead
of a swash plate. The wave cam functions as a drive plate.
[0046] Therefore, the present examples and embodiments are to be
considered as illustrative and not restrictive and the invention is
not to be limited to the details given herein, but may be modified
within the scope and equivalence of the appended claims.
* * * * *