U.S. patent application number 09/790919 was filed with the patent office on 2001-09-06 for compressor with a part of a spring chamber in a rear housing.
Invention is credited to Inoue, Yoshinori, Ota, Masaki, Tarutani, Tomoji, Yoshida, Hiroyuki.
Application Number | 20010019699 09/790919 |
Document ID | / |
Family ID | 18579372 |
Filed Date | 2001-09-06 |
United States Patent
Application |
20010019699 |
Kind Code |
A1 |
Tarutani, Tomoji ; et
al. |
September 6, 2001 |
Compressor with a part of a spring chamber in a rear housing
Abstract
A compressor is provided in which the arrangement and the
position of a spring chamber, in which a coil spring biasing a main
shaft is accommodated, are designed and the various designs of the
compressor is possible. The compressor comprises a main shaft (16),
a front housing (11) which has a shaft aperture that rotatably
supports the front side of the main shaft, a cylinder block (12) in
which a shaft aperture is located on the rear side of the front
housing and rotatably supports the rear side of the main shaft and
in which cylinders are disposed on the outer circumferential side
of the shaft aperture, a rear housing (13) which has a suction
chamber and a discharge chamber that are disposed on the rear side
of the cylinder block and can communicate with the inside of the
cylinders, and a coil spring (32) which biases the main shaft from
a rear side to a front side, wherein the rear housing includes a
recess (13c) or a seat portion which defines at least a part of a
spring chamber that accommodates the coil spring.
Inventors: |
Tarutani, Tomoji;
(Kariya-shi, JP) ; Inoue, Yoshinori; (Kariya-shi,
JP) ; Yoshida, Hiroyuki; (Kariya-shi, JP) ;
Ota, Masaki; (Kariya-shi, JP) |
Correspondence
Address: |
WOODCOCK WASHBURN KURTZ
MACKIEWICZ & NORRIS LLP
46th Floor
One Liberty Place
Philadelphia
PA
19103
US
|
Family ID: |
18579372 |
Appl. No.: |
09/790919 |
Filed: |
February 22, 2001 |
Current U.S.
Class: |
417/269 ;
92/71 |
Current CPC
Class: |
F04B 27/1081
20130101 |
Class at
Publication: |
417/269 ;
92/71 |
International
Class: |
F04B 001/12; F04B
027/08; F01B 003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 3, 2000 |
JP |
2000-058836 |
Claims
1. A compressor comprising: a main shaft which is input from front
side with a driving force from a power source so as to rotate; a
front housing, which has a shaft aperture that rotatably supports
the front side of said main shaft; a cylinder block which has a
shaft aperture that is located on the rear side of said front
housing and rotatably supports the rear side of said main shaft,
and cylinders that are disposed in parallel to said shaft aperture
on the outer circumferential side of said shaft aperture; a rear
housing which has a suction chamber and a discharge chamber that
are disposed on the rear side of said cylinder block and can
communicate with the inside of said cylinders; pistons which are
reciprocatably inserted into said cylinders; a suction valve which
is interposed between said cylinder block and said rear housing and
only allows a gas to be drawn from said suction chamber into said
cylinders; a discharge valve which is interposed between said
cylinder block and said rear housing and only allows the gas to be
discharged from the inside of said cylinders to said discharge
chamber; a swash plate which oscillates in conjunction with the
rotation of said main shaft and can reciprocate said pistons; and a
coil spring which is disposed on the rear side of said main shaft
and biases said main shaft from the rear side to the front side;
wherein, the rear housing includes a recess or a seat portion which
defines at least a part of a spring chamber that accommodates the
coil spring.
2. A compressor, as set forth in claim 1, wherein the spring
chamber communicates with a crank chamber, which is defined by the
front housing and the cylinder block, and the recess or the seat
portion includes a communication passage which communicates the
spring chamber to the suction chamber.
3. A compressor, as set forth in claim 2, wherein the suction
chamber is defined adjacent to the outer circumferential side of
the recess or the seat portion.
4. A compressor, as set forth in claim 1, further comprising a
valve plate which is interposed between the cylinder block and the
rear housing, wherein the valve plate has a hole at a center
portion, through which the coil spring extends.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a compressor used
for an air conditioner (an air conditioning machine) and more
particularly to a compressor used for an air conditioner for a
vehicle (a car air conditioner).
[0003] 2. Description of the Related Art
[0004] It is necessary, for provision of comfort, to use an air
conditioner to adjust the temperature, humidity, air flow and air
cleanness inside a room. The adjustment of temperature and the like
by an air conditioner are accomplished by a compressor in a
refrigerator (or a heat pump) circulating a gas and the gas
performing a refrigeration cycle (or a heat-pump cycle).
[0005] Recently, weight and size reduction are required for all
machines and compressors are also preferably made light and
compact. More particularly, in case of a refrigerator for a car,
the requirement of weight reduction and compact size are high in
view of an improvement of fuel consumption, an improvement in
design flexibility.
[0006] To realize a further weight reduction, a compact size of a
compressor, the new ideas which are not occupied by accepted ideas
are required and the capability of various designs of the
compressors is effective.
[0007] However, conventionally, in a swash plate compressor 400, as
shown in FIG. 4, it has been considered a matter of course that a
coil spring 432, forward biasing the rear end of a main shaft 416,
should be disposed in a spring chamber 440 which is formed by a
valve plate 414 and a shaft aperture 441 provided in shaft center
portion of a cylinder block 412. Thus problems, in which the design
flexibility of a cylinder block 412, a rear housing 413 etc. are
restricted and the further weight reduction, compact size, of a
compressor have been prevented because of the requirement to
provide a suitable space for the spring chamber 440, have
arisen.
[0008] Also, in a conventional wobble type compressor 500, as shown
in FIG. 5, coned disc springs 532 forward biasing the rear end side
of a main shaft 516 may be disposed in a spring chamber 540 which
is formed by a valve plate 514 and a shaft aperture 541 provided in
a shaft center portion of a cylinder block 512. However as a coned
disc spring generally has a large spring constant so that a small
deflection of the coned disc spring considerably varies the
actuating force thereof, precise adjustment of the actuating force
is difficult. For example, if the installation position is moved
slightly by an accumulation of tolerances of elements, the force
which biases a main shaft forward is varied considerably. Thus when
a main shaft is designed to be stably retained by using coned disc
springs, it unpreferably causes problems such as an increase of
manufacturing cost of a compressor.
SUMMARY OF THE INVENTION
[0009] With these above-mentioned problems being taken into
account, the present invention has been developed. The purpose of
the present invention is to provide a compressor in which the main
shaft thereof is biased forward by a coil spring, of which the
design flexibility is increased and of which weight reduction, a
compact size and the like can be facilitated.
[0010] The inventor of the present invention has studied in earnest
to solve the above problems and, after trial and error, has found
that a recess or a seat portion, which defines a portion of a
spring chamber that accommodates a coil spring forward biasing a
main shaft, can be disposed in a rear housing, so that the
compressor of the present invention has been developed.
[0011] That is, in the compressor of the present invention, which
comprises a main shaft that receives a driving force of a power
source from front side and is rotated, a front housing which has a
shaft aperture that rotatably supports the front side of said main
shaft, a cylinder block which has a shaft aperture, that is located
on the rear side of said front housing and rotatably supports the
rear side of said main shaft, and cylinders that are disposed in
parallel to said shaft aperture on the outer circumferential side
of said shaft aperture, a rear housing which has a suction chamber
and a discharge chamber that are disposed on the rear side of said
cylinder block and can communicate with the inside of said
cylinders, pistons which are reciprocatably inserted into said
cylinders, a suction valve which is interposed between said
cylinder block and said rear housing and only allows a gas to be
drawn from said suction chamber into said cylinders, a discharge
valve which is interposed between said cylinder block and said rear
housing and only allows the gas to be discharged from the inside of
said cylinders to said discharge chamber, a swash plate which
oscillates in conjunction with the rotation of said main shaft and
can reciprocate said pistons, and a coil spring which is disposed
on rear side of said main shaft and biases said main shaft from
rear side to front side, the rear housing including a recess or a
seat portion which defines at least a part of a spring chamber that
accommodates the coil spring.
[0012] At least a part of a spring chamber, which accommodates the
coil spring biasing the main shaft, is defined by the recess or the
seat portion which is located in the rear housing, so that the
flexibility of locations in which the spring chamber is positioned
increases and the design flexibility of the compressor is enlarged.
Thus, for example, the weight reduction, compact size and the like
of the compressor and, more concretely, such as a shortening of
longitudinal length thereof, can be realized more easily.
[0013] In addition, as the coil spring biases the main shaft from
rear side to front side, the biasing force can be adjusted easily
and the biasing force does not vary considerably due to a small
movement of the installation position of the coil spring or the
like. Therefore the main shaft is surely retained and an increase
in the manufacturing cost of a compressor and the like does not
occur.
[0014] Also, preferably, the spring chamber in the compressor
communicates with a crank chamber, which is defined by the front
housing and the cylinder block, and the recess or the seat portion
comprises a communication passage which communicates the spring
chamber to the suction chamber.
[0015] In the compressor, the crank chamber communicates with the
suction chamber so as to avoid a pressure increase in the crank
chamber due to blow-by of gas or the like and the communication
passage between the crank chamber and the suction chamber can be
simplified by locating the communication passage thereof in the
spring chamber and the recess or the seat portion which defines at
least a part of the spring chamber.
[0016] Further the suction chamber is more preferably defined
adjacent to the outer circumferential side of the recess or the
seat portion.
[0017] Because the suction chamber is located adjacent to the outer
circumferential side of the recess or the seat portion, the
communication passage can be further shortened, the communication
passage between the spring chamber and the suction chamber can be
simplified and weight reduction, a compact size, an improvement in
production efficiency, can be facilitated.
[0018] Moreover the recess can be shaped as, for example, a
circular hole which comprises a seat surface, that supports the end
surface of the coil spring, in the bottom thereof. The seat portion
may be merely a plane contact surface and may also comprise an
annular groove corresponding to the coil diameter of the coil
spring.
[0019] Also the compressor may be either a swash plate compressor
or a wobble type compressor and also either a valuable displacement
type or a fixed displacement type may be acceptable. The compressor
may be used not only for a refrigeration cycle but also for a heat
pump cycle. Moreover the compressor may be used for general
purposes as well as for vehicular purposes. The pistons thereof may
be either single-headed or double-headed. The swash plate must be
oscillatable but is not necessarily rotatable such as a swash plate
(a rod plate) of a wobble type compressor.
[0020] The present invention may be more fully understood from the
description of the preferred embodiments of the invention set forth
below, together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In the drawings:
[0022] FIG. 1 is a cross-sectional drawing showing the first
embodiment of the compressor according to the present
invention.
[0023] FIG. 2 is a cross-sectional drawing showing the second
embodiment of the compressor according to the present
invention.
[0024] FIG. 3 is a cross-sectional drawing showing the third
embodiment of the compressor according to the present
invention.
[0025] FIG. 4 is a cross-sectional drawing showing a conventional
swash plate compressor.
[0026] FIG. 5 is a cross-sectional drawing showing a conventional
wobble type compressor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0027] (First Embodiment)
[0028] A swash plate compressor 100, which is an embodiment of a
compressor of the present invention, is shown in FIG. 1. The swash
plate compressor 100 is a variable displacement type compressor in
which single-headed pistons 21 and a swash plate 19 are
incorporated.
[0029] The swash plate compressor 100 basically comprises a main
shaft 16, a front housing 11, a cylinder block 12, a rear housing
13, single-headed pistons 21, a swash plate 19, a lug plate 18, a
suction valve 14a, a discharge valve 14b, a valve plate 14 and a
coil spring 32.
[0030] The main shaft 16 is driven by an engine via a pulley (not
shown in the drawing), which is located on the front end of the
swash plate compressor 100, so as to rotate. The front side of the
main shaft 16 is supported by a radial bearing 17a and the rear
side thereof is supported by a radial bearing 17b.
[0031] The radial bearing 17a is inserted in a shaft aperture 11a
located in a shaft center portion of the front housing 11 and the
radial bearing 17b is inserted in a shaft aperture 12b located in a
shaft center portion of the cylinder block 12.
[0032] The cylinder block 12 is disposed on the rear side of the
front housing 11 and, on the outer circumferential side of the
shaft aperture 12b, five sets of cylinders 12a are disposed
uniformly and annularly in parallel to the shaft aperture 12b. A
small shaft aperture 12c, which is smaller diameter than that of
the shaft aperture 12b, is formed on the rear side of the shaft
center portion of the shaft aperture 12b. The small shaft aperture
12c accommodates the rear end of the main shaft 16 and a thrust
bearing 31 and defines a part of a spring chamber 40, which
accommodates a coil spring 32 that biases the main shaft 16 from
the rear side to the front side.
[0033] Then, a crank chamber 15, which accommodates the swash plate
19, is formed in the front side of the cylinder block 12 and
between the front housing 11 and the cylinder block 12.
[0034] The rear housing 13 is disposed on the rear side of the
cylinder block 12 and a suction chamber 13a, a discharge chamber
13b, a recess 13c and a communication passage 13b are defined
therein.
[0035] The suction chamber 13a and the discharge chamber 13b are
located in correspondence to the rear side aperture (bore) of the
cylinders 12a and can communicate with each inside of the cylinders
12a via the suction valve 14a, the valve plate 14 and the discharge
valve 14b which are interposed between the cylinder block 12 and
the rear housing 13.
[0036] However in the suction valve 14a, the discharge valve 14b
and the valve plate 14, circular holes are provided at the shaft
center portion so as to be able to define the spring chamber 40.
The suction valve 14a, the discharge valve 14b and the valve plate
14 are positioned by a knock-out pin, which is provided between the
cylinder block 12 and the rear housing 13, and are interposed and
retained between the outer circumferential side walls thereof. The
suction valve 14a and the discharge valve 14b are both reed valves
and the suction valve 14a allows a refrigerant gas to be drawn only
into the cylinders 12a from the suction chamber 13a and the
discharge valve 14b allows the refrigerant gas to be discharged
only from the inside of the cylinders 12a to the discharge chamber
13b. The valve plate 14 interposed between the suction valve 14a
and the discharge valve 14b, becomes a core bar which supports the
suction valve 14a and the discharge valve 14b.
[0037] The recess 13c has a circular hole shape which opens toward
only front side and the bottom of the recess 13c forms a seat
surface for a rear end of the coil spring 32. Further the spring
chamber 40 is configured by the recess 13c, the small shaft
aperture 12c of the cylinder block 12, the valve plate 14, which is
interposed therebetween.
[0038] Thus as the spring chamber 40 is configured not only in the
cylinder block 12 but also between the cylinder block 12 and the
rear housing 13, a suitable arrangement of the spring chamber 40
can be provided and it becomes possible to enlarge the design
flexibility of the swash plate compressor 100.
[0039] Moreover in the rear housing 13 of this embodiment, the
recess 13c, the suction chamber 13a and the discharge chamber 13b
are defined, in this order, in the direction from the shaft center
portion toward the outer circumferential side and the communication
passage 13d, which is comprised of a small aperture that
communicates the suction chamber 13a to the recess 13c, is provided
by an oblique boring in a partition wall which defines the suction
chamber 13a and the recess 13c.
[0040] As the suction chamber 13a is defined adjacent to the recess
13c which defines a part of the spring chamber 40, a bleed passage
30, in particular the bleed passage 30 of the rear housing 13, can
be simplified and the productivity and the higher design
flexibility of the swash plate compressor 100 are facilitated.
[0041] The swash plate compressor 100 comprises the bleed passage
30 which communicates the suction chamber 13a to the crank chamber
15. This bleed passage 30 comprises an open hole 16d, which
communicates with the crank chamber 15 in vicinity of the radial
bearing 17a, a shaft center passage 16a provided in the center of
the main shaft 16, the spring chamber 40 in the center rear side of
the cylinder block 12 and the communication passage 13d, and
communicates the crank chamber 15 to the suction chamber 13a. By
building the communication between the crank chamber 15 and the
suction chamber 13a, the blow-by gas, which flows into the crank
chamber 15 during operation, is fed back into the suction chamber
13a from the crank chamber 15 through the passage mentioned above.
Thus the swash plate compressor 100 can continue to be operated
even in a large discharge displacement operation without the crank
chamber pressure Pc being abnormally raised due to the blow-by gas.
In addition, in the case that the swash plate compressor 100 does
not need to be driven, the pressure of the suction chamber 13a, the
discharge chamber 13b and the crank chamber 15 can be maintained in
a balanced condition.
[0042] Also the supply passage 24 can connect the discharge chamber
13b to the crank chamber 15 so as to be capable of the
communicating therebetween and a displacement control valve 25 is
located therebetween. The displacement control valve 25 comprises a
linear solenoid valve, is controlled in accordance with the
temperature of a passenger room and can adjust the pressure Pc of
the crank chamber against the suction pressure Ps of refrigerant.
For instance if the displacement control valve 25 is open, as shown
by the double-dot line in FIG. 1, the inclination angle of the
swash plate 19 decreases according to the increase in the pressure
Pc of the crank chamber 15 and the discharge flow rate of the
refrigerant gas decreases. On the contrary, if the displacement
control valve 25 is closed, as shown by a solid line in FIG. 1, the
inclination angle of the swash plate 19 increases according to the
decrease of the pressure Pc of the crank chamber 15 and the
discharge flow rate of the refrigerant gas increases. Thus the
displacement control valve 25 increases and decreases the
differential pressure, which operates on the front and the rear of
the single-headed pistons 21, between the pressure Pc of the crank
chamber and the inside pressure of the cylinders 12a, and the
inclination angle of the swash plate 19 and the stroke of the
single-headed pistons 21 are changed so that the discharge flow
rate of the refrigerant gas can be adjusted.
[0043] The coil spring 32 is accommodated in the spring chamber 40
and is set in the distance between the bottom portion of the recess
13c and the thrust bearing 31. The coil spring 32 biases the main
shaft 16 forward with the set load via the thrust bearing 31. This,
in spite of the vibration during driving the compressor, or the
installation thereof on a vehicle, allows the main shaft 16 to be
retained in a stable position and, for example, the actuation of an
electromagnetic clutch installed on the main shaft 16 can be
secured and an extension of the life of oil seals disposed around
the main shaft 16 can be provided.
[0044] As, by the adjustment of the wire diameter, the coil
diameter, numbers of winding, the wire material and the like of the
coil spring 32, the spring constant, the installation length of the
coil spring 32 can be facilitated to be selected more freely, in
comparison with the coned disc springs, the main shaft 16 can be
retained in a stable manner. In addition, even if the total length
of the main shaft 16, the depth of the recess 13c have some
manufacturing errors (tolerance), the bias force against the main
shaft 16 can not be varied in large degree so that advantageously
the coil spring 32 stably biases the main shaft 16.
[0045] (Second Embodiment)
[0046] A swash plate compressor 200, which is the second embodiment
according to the present invention, is now shown in FIG. 2. In the
FIG. 2, the modified parts relative to the swash plate compressor
100 shown in the FIG. 1 is shown by an enlarged drawing and the
same components as the swash plate compressor 100 are indicated
with common reference numbers.
[0047] In the swash plate compressor 200, a rear housing 213
comprises a plane portion 213c in its shaft center portion. The
rear end surface of a coil spring 232 comes into contact with the
plane portion 213c and the plane portion 213c defines a part of a
spring chamber 240. Thus the plane portion 213c becomes a seat
portion which defines a part of the spring chamber 240 that
accommodates the coil spring 232.
[0048] Different from conventional compressors, in the swash plate
compressor 200, as the spring chamber 240 is not defined by the
suction valve 14a, the valve plate 14 and the like, for example,
the spring chamber 240 can be formed in a larger space. Moreover if
the configuration of the spring chamber 240 and the coil spring 232
can be selected suitably, the design flexibility of the swash plate
compressor 100 can be further more enlarged.
[0049] (Third Embodiment)
[0050] A swash plate compressor 300, which is the third embodiment
according to the present invention, is shown in FIG. 3. In the FIG.
3, the modified parts relative to the swash plate compressor 100
shown in the FIG. 1 are shown by an enlarged drawing and the same
components, as in the swash plate compressor 100, are indicated
with common reference numbers.
[0051] In the swash plate compressor 300, a rear housing 313
comprises a plane portion 313c in the shaft center portion and an
annular groove 313e which surrounds the outer circumferential side
of the plane portion 313c. The plane portion 313c and the annular
groove 313e become a seat portion which defines a part of a spring
chamber 340. In this case, the rear end of a coil spring 332 is
accommodated into an annular groove 313e and the plane portion 313c
present inside thereof supports the coil spring 332 from the
inside. In addition, by adjusting the depth or the width of the
annular groove 313e, various types of the coil spring 332 can be
disposed therein, so that the spring constant and the set load
thereof can be adjusted corresponding to the specification of the
swash plate compressor 300, and the design flexibility of the swash
plate compressor 300 can be increased.
[0052] Also in the swash plate compressors 200 and 300 shown in
FIG. 2 and FIG. 3, each of the communication passages 213d and
313d, which communicate the suction chamber 13a to the spring
chambers 240 and 340, is formed as a narrow groove which is located
in the front side of the rear housing 213 and 313. The
communication passage need not to be limited to a small aperture or
a narrow groove as long as it constitutes the bleed passage 30.
[0053] According to the compressor of the present invention, the
flexibility in disposing the spring chamber, in which the coil
spring that biases the main shaft is accommodated, can be increased
and the design flexibility of the compressor can be enlarged. The
coil spring biases the main shaft forward with a suitable load and,
at the same time, for example, the shortening of the compressor
length in the axial direction thereof can be facilitated.
[0054] While the invention has been described by reference to
specific embodiments chosen for the purposes of illustration, it
should be apparent that numerous modifications could be made
thereto by those skilled in the art without departing from the
basic concept and scope of the invention.
* * * * *