U.S. patent application number 11/571873 was filed with the patent office on 2008-12-11 for variable displacement compressor.
This patent application is currently assigned to Calsonic Kansei Corporation. Invention is credited to Nobuyuki Kobayashi, Hiroyuki Makishima.
Application Number | 20080302236 11/571873 |
Document ID | / |
Family ID | 40175088 |
Filed Date | 2008-12-11 |
United States Patent
Application |
20080302236 |
Kind Code |
A1 |
Makishima; Hiroyuki ; et
al. |
December 11, 2008 |
Variable Displacement Compressor
Abstract
A linkage mechanism (40) of a variable displacement compressor
includes an arm (41) extending from a rotating member (21) toward a
tilting member (24), an arm (43) extending from the tilting member
(24) toward the rotating member (21) and receiving rotary torque
from the arm (41) of the rotating member, a pin (51) fixed to one
of the arm (41) of the rotating member and the arm (43) of the
tilting member, and an axial direction load receiving face (53)
formed on the other of the arm (41) of the rotating member and the
arm (43) of the tilting member and configured to contact with the
pin (51) to receive axial a direction load applied between the
rotating member (21) and the tilting member (24).
Inventors: |
Makishima; Hiroyuki;
(Tochigi, JP) ; Kobayashi; Nobuyuki; (Tochigi,
JP) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
Calsonic Kansei Corporation
|
Family ID: |
40175088 |
Appl. No.: |
11/571873 |
Filed: |
February 21, 2006 |
PCT Filed: |
February 21, 2006 |
PCT NO: |
PCT/JP2006/003044 |
371 Date: |
January 9, 2007 |
Current U.S.
Class: |
91/505 ;
417/222.1 |
Current CPC
Class: |
F04B 27/1072
20130101 |
Class at
Publication: |
91/505 ;
417/222.1 |
International
Class: |
F04B 27/18 20060101
F04B027/18; F04B 1/29 20060101 F04B001/29; F04B 49/12 20060101
F04B049/12 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 9, 2005 |
JP |
2005-066123 |
Claims
1. A variable displacement compressor, comprising: a drive shaft; a
rotating member fixed to the drive shaft and rotating integrally
with the drive shaft; a tilting member attached to the drive shaft
and being changeable a tilt thereof with respect to an axis of the
drive shaft; a linkage mechanism configured to rotate the rotating
member and the tilting member integrally with allowing the tilt of
the tilting member to change; and a piston reciprocating in a
cylinder bore corresponding to rotary movement of the tilting
member; wherein the linkage mechanism includes: an arm extending
from the rotating member; an arm extending from the tilting member
and overlapping with the arm of the rotating member in a rotating
direction; a pin fixed to one of the arm of the rotating member and
the arm of the tilting member; and an axial direction load
receiving face formed on the other of the arm of the rotating
member and the arm of the tilting member and configured to contact
with the pin to receive an axial direction load applied between the
rotating member and the tilting member.
2. The variable displacement compressor according to claim 1,
wherein the arm of the rotating member is formed in a bifurcated
shape divided by a slit to slidably hold the arm of the tilting
member in a sandwiching manner.
3. The variable displacement compressor according to claim 1,
wherein the arm of the tilting member is formed in a bifurcated
shape divided by a slit to slidably hold the arm of the rotating
member in a sandwiching manner.
Description
TECHNICAL FIELD
[0001] The present invention relates to a variable displacement
compressor having a linkage mechanism.
BACKGROUND ART
[0002] A variable displacement compressor includes a drive shaft, a
rotor that is fixed to the drive shaft and rotates integrally with
the drive shaft, a swash plate (cam plate) that is attached to the
drive shaft and changeable its tilt with respect to the axis of the
drive shaft, a linkage mechanism that links the rotor and the swash
plate, and pistons that are engaged to the swash plate. When the
drive shaft rotates, the swash plate rotates with the rotor and the
piston reciprocates corresponding to the inclination angle of the
swash plate. The linkage mechanism links the rotor and the swash
plate so that the inclination angle of the swash plate can be
changed as transferring the rotation of the rotor to the swash
plate. With this, the piston strokes are changed by changing the
inclination angle of the swash plate so as to change the
discharging amount (see Japanese Patent Laid-Open No. 2004-068756,
for example).
[0003] The conventional linkage mechanism includes a projection
extending from the rotor toward the swash plate and a projection
extending from the swash plate toward the rotor. The projection of
the rotor and the projection of the swash plate overlap each other
in the rotating direction and, with this structure, rotary torque
from the rotor is transferred to the swash plate. The projection of
the swash plate slidably contacts with a base of the projection of
the rotor. The base of the projection of the rotor functions an
axial direction load receiving face for receiving an axial
direction load applied to the swash plate. The inclination angle of
the swash plate changes with the slide of the projection of the
swash plate on the pressure receiving face.
DISCLOSURE OF THE INVENTION
[0004] With such a conventional structure, the inclination angle of
the swash plate is changed while a large compression reaction force
(the axial direction load) from the pistons is applied to the
contact between the axial direction load receiving face and the
projection of the swash plate so that the contact are easily worn.
Accordingly, the contact are required to be quenched or the like in
order to enhance their hardness and to prevent such damages. If the
contact are worn down compared to the initial condition, the upper
dead center of the each piston is lowered so that the compressive
performance of the compressor may be decrease.
[0005] The contact between the axial direction load receiving face
and the projection of the swash plate are formed in a complicated
shape so that the inclination angle of the swash plate varies as
the projection of the swash plate slides on the axial direction
load receiving face. Since the contacting face is formed on the
projection of the rotor or the swash plate, difficult processing is
required and manufacturing cost increases.
[0006] The present invention is made based on such a conventional
technique. An object of the present invention is to provide a
variable displacement compressor capable of preventing an abrasion
of a portion where a large axial direction load is applied and
reducing manufacturing cost of the variable displacement
compressor.
[0007] An aspect of the present invention is a variable
displacement compressor, including: a drive shaft; a rotating
member fixed to the drive shaft and rotating integrally with the
drive shaft; a tilting member attached to the drive shaft and being
changeable a tilt thereof with respect to an axis of the drive
shaft; a linkage mechanism configured to rotate the rotating member
and the tilting member integrally as allowing the tilt of the
tilting member; and a piston configured to reciprocate in a
cylinder bore corresponding to rotary movement of the tilting
member. The linkage mechanism includes an arm extending from the
rotating member; an arm extending from the tilting member and
overlapping with the arm of the rotating member in a rotating
direction; a pin fixed to one of the arm of the rotating member and
the arm of the tilting member; and an axial direction load
receiving face formed on the other of the arm of the rotating
member and the arm of the tilting member and configured to contact
with the pin to receive an axial direction load applied between the
rotating member and the tilting member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross-sectional view showing a variable
displacement compressor in a full stroke condition according to an
embodiment of the present invention;
[0009] FIG. 2 is a cross-sectional view showing the variable
displacement compressor in a no-stroke condition;
[0010] FIG. 3 is a perspective view showing an assembly of a drive
shaft, a rotor, and a swash plate of the variable displacement
compressor in a full stroke condition;
[0011] FIG. 4 is a perspective view showing the assembly of the
drive shaft, the rotor, and the swash plate of the variable
displacement compressor in a no-stroke condition;
[0012] FIG. 5 is a side view showing the assembly taken along the
arrow V-V in FIG. 3;
[0013] FIG. 6 is a side view showing the assembly taken along the
arrow VI-VI in FIG. 4;
[0014] FIG. 7 is a cross-sectional view showing a pin of a linkage
mechanism in the variable displacement compressor;
[0015] FIG. 8 is a perspective view showing the first modification
of the first embodiment corresponding to FIG. 3;
[0016] FIG. 9 is a perspective view showing the second modification
of the first embodiment corresponding to FIG. 3; and
[0017] FIG. 10 is a perspective view showing the third modification
of the first embodiment corresponding to FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
[0018] A variable displacement compressor according to an
embodiment of the present invention and a linkage mechanism used
therein will be explained with reference to the drawings.
[0019] Firstly, an over all structure of the variable displacement
compressor will be explained with reference to FIGS. 1 and 2. FIG.
1 shows a full stroke condition and FIG. 2 shows a destroke
condition.
[0020] As shown in FIGS. 1 and 2, a variable displacement
compressor 1 includes a cylinder block 2, a front head 4 attached
to a front end of the cylinder block 2, a rear head 6 attached to a
rear end of the cylinder block 2 via a valve plate 9. The cylinder
block 2, the front head 4, and the rear head 6 are fixed to each
other by a plurality of penetrating bolts B and compose a housing
of the compressor.
[0021] The cylinder block 2 is formed in a substantially
cylindrical shape and has a plurality of cylinder bores 3 placed
evenly spaced apart in a circumferential direction. The front head
2 is attached to the front end of the cylinder block 2 and has a
crank chamber 5 therein. The rear head 6 is attached to the rear
end of the cylinder block 2 via the valve plate 9 and has a suction
chamber 7 and a discharge chamber 8 therein.
[0022] The valve plate 9 is formed with suction ports 11 that
communicates the cylinder bores 3 with the suction chamber 7 and is
formed with discharge ports 12 that communicates the cylinder bores
3 with the discharge chamber 8.
[0023] A valve system (not shown) adapted to open and close the
suction ports 11 is provided on the valve plate 9 at the cylinder
block side. On the other hand, a valve system (not shown) adapted
to open and close the discharge ports 12 is provided on the valve
plate 9 at the rear head side. A gasket is interposed between the
valve plate 9 and the rear head 6 for providing an airtight sealing
property between the suction chamber 7 and the discharge chamber
8.
[0024] A drive shaft 10 is supported by bearings 17, 18 in support
holes 19, 20 that are formed at centers of the cylinder block 2 and
the front head 4 so that the drive shaft 10 is rotatable in the
crank chamber 5.
[0025] the crank chamber 5 accommodates a rotor 21 as a "rotating
member" fixed to the drive shaft 10, a swash plate 24 as a "tilting
member" attached to the drive shaft slidably in the axial direction
and tiltably with respect to the axis of the drive shaft, and a
linkage mechanism 40 for linking the rotor 21 and the swash plate
24. The linkage mechanism 40 links the rotor 21 and the swash plate
24 so that the rotor 21 and the swash plate 24 rotate integrally as
allowing changes of the inclination angle of the swash plate 24.
The swash plate 24 includes a hub 25 attached to the drive shaft 10
and a swash plate body 26 fixed to a boss segment 25a of the hub
25. To the swash plate body 26 of the swash plate 24, a piston 29
is linked via a pair of hemispherical-shaped shoes 30, 30. The
pistons 29 are slidably fit in each cylinder bore 3.
[0026] When the drive shaft 10 rotates, the rotor 21 rotates
integrally with the drive shaft 10, and the swash plate 24 rotates
corresponding to the rotor 21 via the linkage mechanism 40. The
rotation of the swash plate 24 is converted into a reciprocating
movement of the pistons 29 by the pairs of piston shoes 30, 30 so
that the pistons 29 reciprocate in the cylinder bores 3. By the
reciprocation of the pistons 29, refrigerant in the suction chamber
7 is sucked into the cylinder bores 3 through the suction ports 11
of the valve plate 9 to be compressed, and then discharged to the
discharge chamber 8 through the discharge ports 12 of the valve
plate 9.
[0027] Control of Variable Capacity
[0028] In the variable displacement compressor, a pressure control
mechanism is provided. The pressure control mechanism is configured
to adjust a difference in pressure (pressure balance) between the
crank chamber pressure Pc in back of the pistons 29 and the suction
chamber pressure Ps in front of the pistons 29 is provided in order
to change the inclination angle of the swash plate 24. The pressure
control mechanism includes a gas extraction passage (not shown)
that allows the crank chamber 5 to communicate with the suction
chamber 7, an gas supply passage (not shown) that allows the crank
chamber 5 to communicate with the discharge chamber 8, and a
control valve 33 that is provided in the midstream of the gas
supply passage to open and close the gas supply passage.
[0029] When the control valve 33 opens the gas supply passage, the
refrigerant flows from the discharge chamber 8 into the crank
chamber 5 through the gas supply passage, so that the crank chamber
pressure Pc increases. With this, the pressure balance between the
crank chamber pressure Pc and the suction chamber pressure Ps
decreases the inclination angle of the swash plate 24. As a result,
piston strokes become smaller so as to decrease the discharging
amount. On the other hand, when the control valve 33 closes the gas
supply passage, the refrigerant is gradually extracted from the
crank chamber 5 to the suction chamber 7 through the gas extraction
passage, so that the crank chamber pressure Pc reduces. With this,
the pressure balance between the crank chamber pressure Pc and the
suction chamber pressure Ps increases the inclination angle of the
swash plate 24. As a result, the piston strokes become longer so as
to increase the discharging mount. In other words, the inclination
angle of the swash plate 24 reduces when the hub 25 moves toward
the cylinder block 2 and the inclination angle of the swash plate
24 increases when the hub 25 moves away from the cylinder block
2.
[0030] Linkage Mechanism
[0031] A linkage mechanism 40 will be explained with reference to
FIGS. 3 to 7.
[0032] As shown in FIGS. 3 to 6, the linkage mechanism 40 includes
an arm 41 extending from the rotor 21 toward the hub 25 and an arm
43 extending from the hub 25 toward the rotor 21. The arm 41 of the
rotor and the arm 43 of the hub are overlapped in the rotary torque
transfer direction Ft (that is, the rotating direction of the drive
shaft 10). With this structure, the rotary torque of the rotor 21
is transferred to the swash plate 24. In this example, as shown in
FIGS. 3 and 4, the arm 43 is formed in a bifurcated shape having a
slit S extending in the axial direction XY (orthogonally to the
rotary torque transfer direction Ft) and the arm 41 is slidably fit
in the slit S in a sandwiched manner.
[0033] When the swash plate 24 rotates, the pistons 29 reciprocate
so that compression reaction force (axial direction load Fp) from
the pistons is applied to the swash plate 24. The arm 43 of the
swash plate 24 is formed with press-insertion holes 43s (see FIG.
7) that a pin 151 is pressed into and fixed in. An axial direction
load receiving face 53 is formed on an end of the arm 41 of the
rotor 21. The compression reaction force Fp is received at a
contact between the pin 151 and the an axial direction load
receiving face 53.
[0034] The pin 151 extends in a tangential direction of rotary
orbits of the rotating member 21 and the swash plate 24, in other
words, extends toward the rotary torque transfer direction Ft.
Since a large compression reaction force (axial direction load Fp)
is applied to the contact between the pin 151 and the axial
direction pressure receiving face 53 of the rotor 21, the hardness
of the pin 151 and the axial direction pressure receiving face 53
of the rotor 21 is enhanced by a quenching process or the like.
[0035] Effects
[0036] With the above described structure, the present embodiment
brings about the following effects.
[0037] Firstly, according to the present embodiment, the linkage
mechanism 40 includes an arm 41 extending from a rotor 21, an arm
43 extending from a swash plate 24 and receiving rotary torque from
the arm 41 of the rotor, a pin 151 fixed to one of the arm 41 of
the rotor and the arm 43 of the swash plate (the arm 43 of the
swash plate, in this embodiment), and an axial direction load
receiving face 53 formed on the other of the arm 41 of the rotor
and the arm 43 of the swash plate (the arm 41 of the rotor, in this
embodiment) and configured to contact with the pin 151 to receive
compression reaction force Fp (axial direction load) from the
pistons 29.
[0038] Accordingly, the inclination angle of the swash plate 24 is
changed in the condition that great axial direction load Fp
(compression reaction force from the pistons) is applied between
the pin 151 and the axial direction load receiving face 53.
However, since the pin 151 is a member formed separately from the
arm (the arm 43 of the swash plate, in this embodiment), only the
pin 151 can be quenched, etc. in a hardness enhancement process so
that the arm (the arm 43 of the swash plate, in this embodiment) is
not needed to be quenched. As a result, manufacturing cost can be
reduced.
[0039] Further, since the pin 151 is separated form the arm (the
arm 43 of the swash plate, in this embodiment), it is relatively
easy to form the outer surface of the pin 151 to be complicated.
With such a case, the manufacturing cost can be reduced comparing
to the case forming the arm (the arm 43 of the swash plate, in this
embodiment) to be a complicated shape.
[0040] Further, only the pin 151 can be exchanged.
[0041] Secondly, the linkage mechanism has a structure in which one
of the arms 41, 43 (the arm 43 of the swash plate, in this
embodiment) is formed in a bifurcated shape having a slit S and the
other of the arms (the arm 41 of the rotor, in this embodiment) is
slidably fit in the slit S in a sandwiched manner. This structure
is preferable since backlash is hardly provided between the both
arms 41, 43.
[0042] As described above, according to the present invention, the
linkage mechanism includes the arm extending form the rotating
member, the arm extending from the tilting member and overlapped
with the arm of the rotating member, the pin fixed to one of the
arm of the rotating member and the arm of the tilting member, the
axial direction load receiving face formed on the other of the arm
of the rotating member and the arm of the tilting member arm and
configured to contact with the pin to receive axial direction load
between the rotating member and the tilting member. In this
structure, the inclination angle of the tilting member is changed
in a state that great axial direction load (compression reaction
force from the pistons) is applied between the pin and the axial
direction load receiving face. However, since the pin and the arm
are individual members, only the pin can be quenched, etc. in a
hardness enhancement process and the arm is not required to be
quenched. As a result, the manufacturing cost can be reduced.
[0043] It is noted that the present invention should not be limited
to the above described embodiment.
[0044] For example, according to the above embodiment, the pin 51
is fixed to the arm 43 of the swash plate and the axial direction
load receiving face 53 is formed on the arm 41 of the rotor.
However, in the present invention, as shown in the first
modification in FIG. 8 and the second modification in FIG. 9, the
axial direction load receiving face 53 may be formed on the arm 43
of the swash plate and the pin 151 may be fixed to the arm 41 of
the rotor.
[0045] According to the above embodiment, a slit S is provided to
the arm 43 of the swash plate and the arm 41 of the rotor is
slidably held in the slit S. However, in the present invention, as
shown in the second modification in FIG. 9 and the third
modification in FIG. 10, the slit S may be provided to the arm 41
of the rotor and the arm 43 of the swash plate may be slidably fit
in the slit S.
[0046] According to the above embodiment, the cross-section of the
pin is a circular shape; however, in the present invention, it may
be formed in other shapes.
[0047] Further, according to the above embodiment, the swash plate
24 is made in combination of the swash plate body 26 and the hub 25
which are separately formed; however, in the present invention, the
swash plate body and the hub may be formed integrally in advance to
constitute the swash plate. Further, the above embodiment employs a
sleeveless structure in which the swash plate 24 is directly
attached to the drive shaft 10 without any sleeve; however, in the
present invention, the swash plate may be attached to the drive
shaft via a sleeve.
INDUSTRIAL APPLICABILITY
[0048] The present invention may be applied to not only a swash
plate type variable displacement compressor but also a wobble plate
type variable displacement compressor and the present invention may
be implemented with various modifications.
* * * * *