[Technical Field]
[0001] Embodiments of the present invention relate to a rotary compressor and a refrigeration
cycle device.
[Background Art]
[0002] A rotary compressor is used in refrigeration cycle devices. A rotary compressor eccentrically
rotates a roller inside a cylinder chamber to compress a gaseous refrigerant and sends
it to the outside. The roller slides on a surface of a member (a bearing or a partition
plate) forming an end surface of the cylinder chamber. When the member forming the
end surface of the cylinder chamber becomes worn, the compression performance of the
rotary compressor decreases. A rotary compressor in which decrease in compression
performance is able to be curbed is required.
[Citation List]
[Patent Document]
[Patent Document 1]
[Summary of Invention]
[Technical Problem]
[0004] A problem to be solved by the present invention is to provide a rotary compressor
and a refrigeration cycle device in which decrease in compression performance is able
to be curbed.
[Solution to Problem]
[0005] A rotary compressor of the embodiment includes a compression mechanism unit compressing
a gas to be compressed and a lubricating oil which are housed in a container. The
compression mechanism unit includes a shaft, a first cylinder, a second cylinder,
a partition plate, a first bearing, a second bearing, a first flange part, a second
flange part, a first eccentric part, a second eccentric part, a first roller, and
a second roller. The first cylinder forms a first cylinder chamber. The second cylinder
is disposed to be aligned with the first cylinder in an axial direction of the shaft.
The second cylinder forms a second cylinder chamber. The partition plate is disposed
between the first cylinder and the second cylinder. The partition plate has a shaft
hole through which the shaft is passed. The partition plate closes the first cylinder
chamber and the second cylinder chamber. The first bearing is disposed on a side opposite
to the partition plate with the first cylinder sandwiched therebetween. The first
bearing supports the shaft. The second bearing is disposed on a side opposite to the
partition plate with the second cylinder sandwiched therebetween. The second bearing
supports the shaft. The first flange part is formed on the first cylinder side of
the first bearing. The first flange part has a first surface which closes the first
cylinder chamber. The second flange part is formed on the second cylinder side of
the second bearing. The second flange part has a second surface which closes the second
cylinder chamber. The first eccentric part is formed in a columnar shape. The first
eccentric part is formed on the shaft. The first eccentric part is disposed at a position
of the first cylinder in the axial direction. The second eccentric part is formed
on the shaft. The second eccentric part is disposed at a position of the second cylinder
in the axial direction. The first roller is disposed along an outer circumferential
surface of the first eccentric part. The first roller moves along the first surface
of the first flange part in accordance with rotation of the shaft. The second roller
is disposed along an outer circumferential surface of the second eccentric part. The
second roller moves along the second surface of the second flange part in accordance
with rotation of the shaft. A thickness of the partition plate in the axial direction
is smaller than a thickness of the first flange part in the axial direction and a
thickness of the second flange part in the axial direction. The first bearing includes
a first groove part formed in a ring shape on a surface of the first flange part and
disposed coaxially with the shaft. The second bearing includes a second groove part
formed in a ring shape on a surface of the second flange part and disposed coaxially
with the shaft. An area of a portion in which an end surface of the first roller on
the partition plate side is able to be exposed to the shaft hole according to movement
of the first roller is defined as Sc1. An area of a portion in which an end surface
of the first roller on the first flange part side is able to be exposed to an inner
region of an outer circumference of the first groove part according to the movement
of the first roller is defined as Sel. At this time, 1 < Scl/Sel ≤ 1.6 is established.
An area of a portion in which an end surface of the second roller on the partition
plate side is able to be exposed to the shaft hole according to movement of the second
roller is defined as Sc2. An area of a portion in which an end surface of the second
roller on the second flange part side is able to be exposed to an inner region of
an outer circumference of the second groove part according to the movement of the
second roller is defined as Se2. At this time, 1 < Sc2/Se2 ≤ 1.6 is established. A
solid lubricating film is formed on the first surface of the first flange part and
the second surface of the second flange part.
[Brief Description of Drawings]
[0006]
Fig. 1 is a schematic configuration view of a refrigeration cycle device including
a cross-sectional view of a rotary compressor of the embodiment.
Fig. 2 is an enlarged view of a compression mechanism unit.
Fig. 3 is a cross-sectional view of a compression mechanism unit 33 along line F-F
of Fig. 2.
Fig. 4 is a first explanatory view of a pressure receiving portion of a first roller.
Fig. 5 is a second explanatory view of a pressure receiving portion of the first roller.
Fig. 6 is a third explanatory view of a pressure receiving portion of the first roller.
Fig. 7 is a fourth explanatory view of a pressure receiving portion of the first roller.
Fig. 8 is an explanatory view of inner pressure receiving areas of the first roller
and a second roller.
Fig. 9 is an explanatory view of outer pressure receiving areas of the first roller
and the second roller.
Fig. 10 is a graph showing a transition of an amount of wear on a first surface of
the first flange part.
[Description of Embodiments]
[0007] Hereinafter, a rotary compressor and a refrigeration cycle device of an embodiment
will be described with reference to the drawings.
[0008] In the present application, a Z direction, an R direction and a θ direction of a
polar coordinate system are defined as follows. The Z direction is an axial direction
of a shaft 31. A +Z direction is a direction from a compression mechanism unit 33
toward an electric motor unit 32. For example, the Z direction may be a vertical direction,
and the +Z direction may be vertically upward. Further, there are cases in which the
Z direction is referred to as an axial direction Z. The R direction is a radial direction
of the shaft 31. A +R side is an outer side in the radial direction and is a side
away from a central axis of the shaft 31. Further, there are cases in which the R
direction is referred to as a radial direction R. The θ direction is a circumferential
direction around the central axis of the shaft 31. Further, there are cases in which
the θ direction is referred to as a circumferential direction θ.
[0009] A refrigeration cycle device will be briefly described.
[0010] Fig. 1 is a schematic configuration view of a refrigeration cycle device including
a cross-sectional view of a rotary compressor 2 of the present embodiment. A refrigeration
cycle device 1 includes the rotary compressor 2, a radiator (for example, a condenser)
3 connected to the rotary compressor 2, an expansion device (for example, an expansion
valve) 4 connected to the radiator 3, and a heat absorber (for example, a vaporizer)
5 connected to the expansion device 4. The refrigeration cycle device 1 contains a
refrigerant such as carbon dioxide (CO
2). The refrigerant circulates in the refrigeration cycle device 1 while changing its
phase.
[0011] The rotary compressor 2 is a so-called rotary type compressor. The rotary compressor
2, for example, compresses a low-pressure gaseous refrigerant (fluid) taken into the
inside into a high-temperature and high-pressure gaseous refrigerant. Further, a specific
configuration of the rotary compressor 2 will be described later.
[0012] The radiator 3 radiates heat from the high-temperature and high-pressure gaseous
refrigerant discharged from the rotary compressor 2.
[0013] The expansion device 4 reduces a pressure of the high-pressure refrigerant sent from
the radiator 3 to convert the high-pressure refrigerant into a low-temperature and
low-pressure liquid refrigerant.
[0014] The heat absorber 5 vaporizes the low-temperature and low-pressure liquid refrigerant
sent from the expansion device 4 to convert the low-temperature and low-pressure liquid
refrigerant into a low-pressure gaseous refrigerant. In the heat absorber 5, vaporization
of the low-pressure liquid refrigerant removes vaporization heat from the surroundings,
and thus the surroundings are cooled. The low-pressure gaseous refrigerant that has
passed through the heat absorber 5 is taken into the rotary compressor 2 described
above.
[0015] As described above, in the refrigeration cycle device 1 of the present embodiment,
a refrigerant serving as a working fluid circulates while changing its phase between
a gaseous refrigerant and a liquid refrigerant, and heating, cooling, or the like
is performed by utilizing such heat radiation and heat absorption.
[0016] A specific configuration of the rotary compressor 2 will be described.
[0017] The rotary compressor 2 of the present embodiment includes a compressor main body
11 and an accumulator 12.
[0018] The accumulator 12 is a so-called gas-liquid separator. The accumulator 12 is provided
between the heat absorber 5 and the compressor main body 11 described above. The accumulator
12 is connected to the compressor main body 11 through a suction pipe 21. The accumulator
12 supplies a gaseous refrigerant vaporized by the heat absorber 5 to the compressor
main body 11 through the suction pipe 21.
[0019] The compressor main body 11 includes the shaft 31, the electric motor unit 32 that
rotates the shaft 31, the compression mechanism unit 33 that compresses the gaseous
refrigerant by rotation of the shaft 31, and a cylindrical airtight container 34 accommodating
the shaft 31, the electric motor unit 32, and the compression mechanism unit 33.
[0020] The shaft 31 and the airtight container 34 are disposed coaxially with respect to
an axial center (axis) O of the shaft 31. Further, the axial center O of the shaft
31 means a center (rotation center) of the shaft 31. The electric motor unit 32 is
disposed on the +Z side (upper side in Fig. 1) along the axial center O in the airtight
container 34. The compression mechanism unit 33 is disposed on the -Z side (lower
side in Fig. 1) along the axial center O in the airtight container 34.
[0021] The shaft 31 penetrates the electric motor unit 32 and extends inside the compression
mechanism unit 33 in the axial direction Z.
[0022] The electric motor unit 32 is a so-called inner rotor type DC brushless motor. Specifically,
the electric motor unit 32 includes a stator 36 and a rotor 37. The stator 36 is formed
in a cylindrical shape and is fixed to an inner wall surface of the airtight container
34 by shrink-fitting or the like. The rotor 37 is disposed on an inner side of the
stator 36. The rotor 37 is connected to an upper portion of the shaft 31. The rotor
37 rotationally drives the shaft 31 when a current is supplied to a coil provided
in the stator 36.
[0023] Next, the compression mechanism unit 33 will be described.
[0024] Fig. 2 is an enlarged view of the compression mechanism unit. The compression mechanism
unit 33 is a multi-cylinder compression mechanism unit having a plurality of cylinder
chambers. For example, the compression mechanism unit 33 of the embodiment may be
a two-cylinder compression mechanism unit having two cylinder chambers 51a and 52a.
The compression mechanism unit 33 includes a plurality of cylinders 51 and 52, a partition
plate 53, a main bearing (first bearing) 54, a sub bearing (second bearing) 55, a
plurality of rollers 56 and 57, a main muffler member 91, and a sub muffler member
92.
[0025] The plurality of cylinders include a first cylinder 51 and a second cylinder 52.
The first cylinder 51 and the second cylinder 52 are disposed to be aligned in the
axial direction Z. The first cylinder 51 and the second cylinder 52 are formed in
a cylindrical shape that opens in the axial direction Z. The first cylinder 51 and
the second cylinder 52 are disposed coaxially with the shaft 31 on an outer side of
the shaft in the radial direction R. Thereby, an internal space serving as a first
cylinder chamber 51a is formed in the first cylinder 51. An inner circumferential
surface of the first cylinder 51 forms an outer circumferential surface of the ring-shaped
first cylinder chamber 51a. An internal space serving as a second cylinder chamber
52a is formed in the second cylinder 52. An inner circumferential surface of the second
cylinder 52 forms an outer circumferential surface of the ring-shaped second cylinder
chamber 52a.
[0026] In the present application, the partition plate 53 side of the first cylinder 51
and the second cylinder 52 in the axial direction Z may be referred to as an "inner
side." Further, the main bearing 54 side of the first cylinder 51 and the sub bearing
55 side of the second cylinder 52 in the axial direction Z may be referred to as an
"outer side."
[0027] The partition plate 53 is disposed between the first cylinder 51 and the second cylinder
52 in the axial direction Z and is sandwiched between the first cylinder 51 and the
second cylinder 52. The partition plate 53 faces the internal space of the first cylinder
chamber 51a in the axial direction Z to close the first cylinder chamber 51a. Similarly,
the partition plate 53 faces the internal space of the second cylinder chamber 52a
to close the second cylinder chamber 52a. Also, a shaft hole 53h through which the
shaft 31 passes in the axial direction Z is provided in the partition plate 53. The
shaft 31 described above penetrates the first cylinder 51, the second cylinder 52,
and the partition plate 53.
[0028] As illustrated in Fig. 1, a first suction hole 76 extending in the radial direction
R is formed in the first cylinder 51. An inner end portion of the first suction hole
76 in the radial direction R opens to the first cylinder chamber 51a. An outer end
portion of the first suction hole 76 in the radial direction R is connected to the
suction pipe 21 extending from the accumulator 12. Thereby, the first cylinder chamber
51a can suction the gaseous refrigerant from the accumulator 12. Also, a second suction
hole 79 extending in the axial direction Z is formed in the first cylinder 51, the
partition plate 53, and the second cylinder 52. An upper end portion of the second
suction hole 79 in the axial direction Z opens to the first suction hole 76. That
is, the second suction hole 79 is formed to be branched from the first suction hole
76. A lower end portion of the second suction hole 79 in the axial direction Z opens
to the second cylinder chamber 52a. Thereby, the second cylinder chamber 52a can suction
the gaseous refrigerant from the accumulator 12.
[0029] The main bearing 54 is positioned on a side opposite to the partition plate 53 with
the first cylinder 51 sandwiched therebetween. The main bearing 54 rotatably supports
the shaft 31. The main bearing 54 includes a first flange part 54f formed at an end
portion on the first cylinder 51 side. The first flange part 54f has a first surface
54s that closes the first cylinder chamber 51a.
[0030] The sub bearing 55 is positioned on a side opposite to the partition plate 53 with
the second cylinder 52 sandwiched therebetween. The sub bearing 55 rotatably supports
the shaft 31. The sub bearing 55 includes a second flange part 55f formed at an end
portion on the second cylinder 52 side. The second flange part 55f has a second surface
55s that closes the second cylinder chamber 52a.
[0031] A first eccentric part 41 and a second eccentric part 42 are provided to be aligned
in the axial direction Z on the shaft 31 described above. The first eccentric part
41 is provided at a position corresponding to the first cylinder chamber 51a in the
axial direction Z and is disposed inside the first cylinder chamber 51a. The second
eccentric part 42 is provided at a position corresponding to the second cylinder chamber
52a in the axial direction Z and is disposed inside the second cylinder chamber 52a.
The first eccentric part 41 and the second eccentric part 42 are each formed in a
columnar shape in the axial direction Z and are eccentric with respect to the axial
center O by the same amount in the radial direction R. The first eccentric part 41
and the second eccentric part 42 may be formed, for example, to have the same shape
and the same size in a plan view from the axial direction Z and may be disposed, for
example, with a phase difference of 180° in the circumferential direction θ.
[0032] The plurality of rollers include a first roller 56 and a second roller 57. The first
roller 56 and the second roller 57 are each formed in a cylindrical shape in the axial
direction Z. The first roller 56 is fitted along an outer circumferential surface
of the first eccentric part 41 and is disposed in the first cylinder chamber 51a.
Similarly, the second roller 57 is fitted along an outer circumferential surface of
the second eccentric part 42 and is disposed in the second cylinder chamber 52a. Gaps
for allowing relative rotation of the rollers 56 and 57 with respect to the eccentric
parts 41 and 42 are respectively provided between inner circumferential surfaces of
the rollers 56 and 57 and the eccentric parts 41 and 42. The first roller 56 and the
second roller 57 eccentrically rotate inside the cylinder chambers 51a and 52a in
accordance with rotation of the shaft 31 while outer circumferential surfaces of the
rollers 56 and 57 are in sliding contact with inner circumferential surfaces of the
cylinders 51 and 52.
[0033] Next, an internal configuration of the cylinder will be described.
[0034] An internal configuration of the first cylinder 51 and an internal configuration
of the second cylinder 52 are substantially the same as each other except for portions
that differ according to phase differences between the eccentric parts 41 and 42 and
between the rollers 56 and 57. Therefore, here, the internal configuration of the
first cylinder 51 will be described as a representative. Then, constituents of the
second cylinder 52 having the same functions as those in the first cylinder 51 will
be denoted by the same reference signs and description thereof will be omitted.
[0035] Fig. 3 is a cross-sectional view of the compression mechanism unit 33 along line
F-F of Fig. 2.
[0036] As illustrated in Fig. 3, a vane groove 71 extending outward in the radial direction
R is provided on the inner circumferential surface of the first cylinder 51. A vane
72 that is slidably movable in the radial direction R is inserted into the vane groove
71. The vane 72 is biased inward in the radial direction R by a biasing means (not
illustrated), and a distal end thereof is brought into contact with the outer circumferential
surface of the first roller 56 in the first cylinder chamber 51a. Thereby, the vane
72 partitions the inside of the first cylinder chamber 51a into a suction chamber
74 and a compression chamber 75. The vane 72 moves back and forth in the first cylinder
chamber 51a as the first roller 56 rotates eccentrically. Thereby, a suction operation
of suctioning the gaseous refrigerant into the suction chamber 74 and a compression
operation of compressing the gaseous refrigerant in the compression chamber 75 are
performed.
[0037] Also, the above-described first suction hole 76 and a discharge groove 77 are provided
in the first cylinder 51. The inner end portion of the first suction hole 76 in the
radial direction R opens to the suction chamber 74 of the first cylinder chamber 51a.
The discharge groove 77 is provided in the compression chamber 75. The discharge groove
77 is provided on the inner circumferential surface of the first cylinder 51 in the
axial direction Z and communicates with a main bearing discharge hole to be described
later. The discharge groove 77 guides the gaseous refrigerant compressed in the compression
chamber 75 to the main bearing discharge hole. On the other hand, a discharge groove
77 provided in the second cylinder 52 communicates with a sub bearing discharge hole
to be described later. The discharge groove 77 of the second cylinder 52 guides the
gaseous refrigerant compressed in a compression chamber 75 to the sub bearing discharge
hole.
[0038] As illustrated in Fig. 2, the main muffler member 91 forms a main muffler chamber
91a between itself and the main bearing 44. The gaseous refrigerant compressed in
the compression chamber 75 of the first cylinder chamber 51a is discharged to the
main muffler chamber 91a from the main bearing discharge hole (not illustrated) formed
in the first flange part 54f. The gaseous refrigerant discharged into the main muffler
chamber 91a is discharged into the airtight container 34 from a main muffler chamber
discharge port 91e. The sub muffler member 92 forms a sub muffler chamber 92a between
itself and the sub bearing 55. The gaseous refrigerant compressed in the compression
chamber 75 of the second cylinder 52 is discharged to the sub muffler chamber 92a
from the sub bearing discharge hole (not illustrated) formed in the second flange
part 55f. The sub muffler chamber 92a communicates with the main muffler chamber 91a
through a through hole (not illustrated) formed in the second cylinder 52, the partition
plate 53, and the first cylinder 51. Therefore, the gaseous refrigerant discharged
to the sub muffler chamber 92a moves to the main muffler chamber 91a and is discharged
from the main muffler chamber discharge port 91e into the airtight container 34.
[0039] The airtight container 34 includes a discharge pipe 35 on the +Z side of the rotor
37 of the electric motor unit 32. The discharge pipe 35 discharges the gaseous refrigerant
discharged into the airtight container 34 to constituent units of the refrigeration
cycle device outside the airtight container 34 such as the radiator 3.
[0040] The first flange part 54f of the main bearing 54 described above has a first groove
part 61. The first groove part 61 is formed on a surface of the first flange part
54f on the first cylinder 51 side. The first groove part 61 is formed in a ring shape
when viewed from the axial direction Z. The first groove part 61 is disposed coaxially
with the shaft 31 on an outer side of the shaft 31 in the radial direction R. Thereby,
a first collar 66 that supports the shaft 31 is formed between the shaft 31 and the
first groove part 61.
[0041] Similarly, the second flange part 55f of the sub bearing 55 has a second groove part
62. A second collar 67 that supports the shaft 31 is formed between the shaft 31 and
the second groove part 62.
[0042] In the multi-cylinder compression mechanism unit 33, since a plurality of cylinders
are disposed between the main bearing 54 and the sub bearing 55, a distance between
the main bearing 54 and the sub bearing 55 increases. Therefore, the shaft 31 is likely
to be bent between the main bearing 54 and the sub bearing 55. Even when the shaft
31 rotates while being bent, the first collar 66 and the second collar 67 support
the shaft 31 while bending together with the shaft 31. Thereby, wear of the main bearing
54 and the sub bearing 55 due to rotation of the shaft 31 is suppressed.
[0043] A thickness Tc of the partition plate 53 in the axial direction Z is smaller than
a thickness Te1 of the first flange part 54f in the axial direction Z and a thickness
Te2 of the second flange part 55f in the axial direction Z. Thereby, the distance
between the main bearing 54 and the sub bearing 55 decreases. Accordingly, bending
of the shaft 31 is suppressed.
[0044] Next, an oil supply passage 80 provided in the compression mechanism unit 33 will
be described.
[0045] A lubricating oil is contained in the airtight container 34. A polyalkylene glycol
(PAG) oil is contained as the lubricating oil (refrigerating machine oil). A PAG oil
has a smaller decrease in viscosity when a refrigerant is dissolved compared to other
lubricating oils such as a polyol ester (POE) oil and a polyvinyl ether (PVE) oil.
Particularly, even when a carbon dioxide refrigerant is compressed to a high temperature,
since the PAG oil has a small decrease in viscosity, a satisfactory lubrication state
is maintained.
[0046] As illustrated in Fig. 2, the oil supply passage 80 includes a main passage 81 provided
in the shaft 31, a sub-passage 82 and a communication passage 84 provided in the first
eccentric part 41, and an end portion passage 85 provided in the +Z direction of the
first eccentric part 41. Similarly, a sub-passage and a communication passage are
also provided in the second eccentric part 42. Similarly, an end portion passage is
also provided in the -Z direction of the second eccentric part 42. Here, the sub-passage
82, the communication passage 84, and the end portion passage 85 provided in the first
eccentric part 41 will be described as representatives.
[0047] The main passage 81 is provided coaxially with the axial center O and is formed inside
the shaft 31. The main passage 81 extends inside the shaft 31 in the axial direction
Z. The main passage 81 opens inside the airtight container 34 at the end portion of
the shaft 31 supported by the sub bearing 45. A part of the compression mechanism
unit 33 is immersed in the lubricating oil contained in the airtight container 34.
The lubricating oil flows into the main passage 81. A pumping means (not illustrated)
such as a torsion plate for pumping up the lubricating oil into the main passage 81
in accordance with rotation of the shaft 31 is provided inside the main passage 81.
[0048] The sub-passage 82 is a groove provided on the outer circumferential surface of the
first eccentric part 41. The sub-passage 82 is formed between the outer circumferential
surface of the first eccentric part 41 and the inner circumferential surface of the
first roller 56. The sub-passage 82 extends throughout the first eccentric part 41
in the axial direction Z. The communication passage 84 is provided inside the first
eccentric part 41 in the radial direction R. The communication passage 84 is provided
between the main passage 81 and the sub-passage 82 to connect the main passage 81
and the sub-passage 82. The lubricating oil pumped up into the main passage 81 flows
into the sub-passage 82 through the communication passage 84 due to a centrifugal
force according to rotation of the shaft 31. Further, the lubricating oil is supplied
from the sub-passage 82 to various sliding portions of the compression mechanism unit
33.
[0049] An inner end portion of the end portion passage 85 in the radial direction R opens
to the main passage 81. An outer end portion of the end portion passage 85 in the
radial direction R opens to the outer circumferential surface of the shaft 31. The
lubricating oil pumped up into the main passage 81 is supplied to the outer circumferential
surface of the shaft 31 through the end portion passage 85 by the centrifugal force
according to the rotation of the shaft 31. Further, the lubricating oil is supplied
from the outer circumferential surface of the shaft 31 to various sliding portions
of the compression mechanism unit 33.
[0050] A pressure received by each of the rollers 56 and 57 in the axial direction Z will
be described. First, a pressure received by an inner end surface of each of the rollers
56 and 57 (end surface on the partition plate 53 side) will be described.
[0051] As described above, the gaseous refrigerant compressed by the compression mechanism
unit 33 is discharged into the airtight container 34. The gaseous refrigerant and
lubricating oil inside the airtight container 34 are in a high-pressure state. Similarly,
a portion to which the lubricating oil is supplied through the oil supply passage
80 is also in a high-pressure state. The lubricating oil is supplied to a central
portion region 53A, which is an inner region of the shaft hole 53h of the partition
plate 53, via the sub-passage 82 of the oil supply passage 80. The lubricating oil
is supplied to a first end portion region 61 A, which is an inner region of an outer
circumference of the first groove part 61 of the first flange part 54f, via the sub-passage
82 and the end portion passage 85 of the oil supply passage 80. Further, a distal
end of the first collar 66 in the -Z direction is disposed in the +Z direction with
respect to a surface of the first flange part 54f on the first cylinder 51 side. Therefore,
the first end portion region 61A is a region from the outer circumference of the shaft
31 to the outer circumference of the first groove part 61 in the radial direction
R. Similarly, the lubricating oil is also supplied to a second end portion region
62A which is an inner region of an outer circumference of the second groove part 62
of the second flange part 55f. Accordingly, the central portion region 53A, the first
end portion region 61A, and the second end portion region 62A are all in a high-pressure
state.
[0052] Fig. 4 is a first explanatory view of a pressure receiving portion of the first roller.
Similarly, Fig. 5 is a second explanatory view, Fig. 6 is a third explanatory view,
and Fig. 7 is a fourth explanatory view. Figs, 4 to 7 are cross-sectional views of
a main part along line F-F of Fig. 2.
[0053] It is necessary to suppress a direct inflow of the lubricating oil from the central
portion region 53A to the first cylinder chamber 51a. Therefore, in the process of
eccentric rotation of the first roller 56, an outer circumference of the central portion
region 53A (inner circumference of the shaft hole 53h) is always disposed on an inner
side of the outer circumference of the first roller 56. Also, the first eccentric
part 41 is disposed in the first cylinder chamber 51a through the shaft hole 53h.
Therefore, an outer diameter of the first eccentric part 41 is smaller than an inner
diameter of the shaft hole 53h. Accordingly, in the process of the eccentric rotation
of the first roller 56, a part of the outer circumference of the central portion region
53A (inner circumference of the shaft hole 53h) is disposed on an outer side of the
inner circumference of the first roller 56 (outer circumference of the first eccentric
part 41).
[0054] Thereby, as illustrated in Fig. 4, a part of the outer circumference of the central
portion region 53A is disposed between the inner circumference and the outer circumference
of the first roller 56. That is, a part of the inner end surface of the first roller
56 becomes an exposed region 56p exposed to the central portion region 53A.
[0055] Figs. 5 to 7 each illustrate a state in which the first roller 56 is eccentrically
rotated by 90 degrees from Fig. 4. Due to the eccentric rotation of the first roller
56, each part of the inner end surface of the first roller 56 along the inner circumference
can be an exposed region 56p.
[0056] Fig. 8 is an explanatory view of pressure receiving areas of inner end surfaces of
the first roller and the second roller. Due to the eccentric rotation of the first
roller 56, a ring-shaped region of the inner end surface of the first roller 56 along
the inner circumference is a portion that can be exposed to the central portion region
53A. This ring-shaped region is a high-pressure region c1 that receives a high pressure
from the central portion region 53A. An area (inner pressure receiving area) of the
high-pressure region c1 on the inner end surface of the first roller 56 is defined
as Sc1.
[0057] Similarly, a ring-shaped region of the inner end surface of the second roller 57
along the inner circumference can be exposed to the central portion region 53A. This
ring-shaped region is a high-pressure region c2 that receives a high pressure from
the central portion region 53A. An area (inner pressure receiving area) of the high-pressure
region c2 on the inner end surface of the second roller 57 is defined as Sc2.
[0058] The internal configuration of the first cylinder 51 and the internal configuration
of the second cylinder 52 are the same except that the eccentric parts 41 and 42 are
disposed in different phases from each other in the circumferential direction θ. Also,
an outer diameter of the central portion region 53A (inner diameter of the shaft hole
53h) is constant in the axial direction Z. Therefore, the inner pressure receiving
area Sc1 of the first roller 56 and the inner pressure receiving area Sc2 of the second
roller 57 are equivalent.
[0059] Next, a pressure received by an outer end surface of each of the rollers 56 and 57
(end surface on the main bearing 54 side or the sub bearing 55 side) will be described.
[0060] As illustrated in Fig. 2, it is necessary to suppress a direct inflow of the lubricating
oil from the first end portion region 61A into the first cylinder chamber 51a. Therefore,
in the process of the eccentric rotation of the first roller 56, an outer circumference
of the first end portion region 61 A (outer circumference of the first groove part
61) is always disposed on an inner side of the outer circumference of the first roller
56. Also, in the process of the eccentric rotation of the first roller 56, a part
of the outer circumference of the first end portion region 61A is disposed on an outer
side of the inner circumference of the first roller 56. Accordingly, a part of the
outer circumference of the first end portion region 61A is disposed between the inner
circumference and the outer circumference of the first roller 56. A part of an outer
end surface of the first roller 56 is exposed to the first end portion region 61A.
[0061] Fig. 9 is an explanatory view of outer pressure receiving areas of the first roller
and the second roller.
[0062] Due to the eccentric rotation of the first roller 56, a ring-shaped region of the
outer end surface of the first roller 56 along the inner circumference is a portion
that can be exposed to the first end portion region 61A. This ring-shaped region is
a high-pressure region e1 that receives a high pressure from the first end portion
region 61A. An area of the high-pressure region e1 (outer pressure receiving area)
on the outer end surface of the first roller 56 is defined as Se1.
[0063] Similarly, a ring-shaped region of the outer end surface of the second roller 57
along the inner circumference can be exposed to the second end portion region 62A.
This ring-shaped region is a high-pressure region e2 that receives a high pressure
from the second end portion region 62A. An area of the high-pressure region e2 (outer
pressure receiving area) on the outer end surface of the second roller 57 is defined
as Se2.
[0064] An outer diameter of the first end portion region 61A (outer diameter of the first
groove part 61) and an outer diameter of the second end portion region 62A (outer
diameter of the second groove part 62) may be the same as or different from each other.
When both the outer diameters are the same as each other, the outer pressure receiving
area Se1 of the first roller 56 and the outer pressure receiving area Se2 of the second
roller 57 are the same. When both the outer diameters are different from each other,
the outer pressure receiving area Se1 of the first roller 56 and the outer pressure
receiving area Se2 of the second roller 57 are different.
[0065] Next, a force received by the inner end surface and a force received by the outer
end surface of each of the rollers 56 and 57 are compared.
[0066] As illustrated in Fig. 2, an outer diameter (inner diameter of the shaft hole 53h)
Dc of the central portion region 53A is larger than an outer diameter (outer diameter
of the first groove part 61) De1 of the first end portion region 61A. Therefore, the
inner pressure receiving area Sc1 of the first roller 56 is larger than the outer
pressure receiving area Se1 of the first roller 56. That is, 1 < Scl/Sel is established.
Further, a pressure in the central portion region 53A is equivalent to a pressure
in the first end portion region 61A. Accordingly, a force received by the inner end
surface of the first roller 56 in the +Z direction is larger than a force received
by the outer end surface thereof in the -Z direction. Thereby, the first roller 56
is pressed toward the first flange part 54f of the main bearing 54.
[0067] Similarly, the outer diameter (inner diameter of the shaft hole 53h) Dc of the central
portion region 53A is larger than an outer diameter (outer diameter of the second
groove part 62) De2 of the second end portion region 62A. Therefore, the inner pressure
receiving area Sc2 of the second roller 57 is larger than the outer pressure receiving
area Se2 of the second roller 57. That is, 1 <Sc2/Se2 is established. Further, a pressure
in the central portion region 53A is equivalent to a pressure in the second end portion
region 62A. Accordingly, a force received by the inner end surface of the second roller
57 in the -Z direction is larger than a force received by the outer end surface thereof
in the +Z direction. Thereby, the second roller 57 is pressed toward the second flange
part 55f of the sub bearing 55.
[0068] As described above, the thickness Tc of the partition plate 53 in the axial direction
Z is smaller than the thickness Te1 of the first flange part 54f in the axial direction
Z and the thickness Te2 of the second flange part 55f in the axial direction Z. In
this case, since the partition plate 53 is likely to be bent, frictional forces of
the partition plate 53 against the first roller 56 and the second roller 57 may increase.
On the other hand, the first roller 56 is pressed toward the first flange part 54f,
and the second roller 57 is pressed toward the second flange part 55f. Thereby, friction
of the first roller 56 and the second roller 57 with the partition plate 53 is suppressed.
[0069] A solid lubricating film 59 is formed on the first surface 54s of the first flange
part 54f that forms the outer end surface of the first cylinder chamber 51a. The solid
lubricating film 59 may be formed only on the first surface 54s or may be formed on
the entire surface of the main bearing 54. As the solid lubricating film 59, a manganese
phosphate film or a molybdenum dioxide film is preferably formed. These solid lubricating
films 59 have excellent wear resistance and contribute to reduction in initial friction
with the first roller 56. Further, a manganese phosphate film may be formed on a lower
layer that is in contact with the first surface 54s, and a molybdenum dioxide film
may be formed on an upper layer that is in contact with the first roller 56. Since
a manganese phosphate film has excellent wear resistance, reliability of the compressor
is improved. Since a molybdenum dioxide film has a large effect in reducing initial
friction, initial characteristics of the compressor are improved.
[0070] Similarly, the solid lubricating film 59 is also formed on the second surface 55s
of the second flange part 55f that forms the outer end surface of the second cylinder
chamber 52a.
[0071] As described above, the first roller 56 is pressed toward the first flange part 54f,
and the second roller 57 is pressed toward the second flange part 55f. Accordingly,
friction of the first roller 56 and the second roller 57 with the partition plate
53 is suppressed. Therefore, the solid lubricating film 59 may be formed only on the
first flange part 54f and the second flange part 55f. It is not necessary to form
the solid lubricating film 59 on the partition plate 53 and the rollers 56 and 57.
Accordingly, costs of the rotary compressor 2 are reduced.
[0072] Fig. 10 is a graph showing a transition of an amount of wear on the first surface
of the first flange part. In Fig. 10, an amount of wear is denoted by two types of
marks according to a magnitude of a ratio of the inner pressure receiving area Sc1
to the outer pressure receiving area Se1 of the first roller 56. An amount of wear
when 1 < Scl/Sel ≤ 1.6 is denoted by a mark of □. An amount of wear when 1.6 < Scl/Sel
is denoted by a mark of ×. In Fig. 10, an amount of wear of a manganese phosphate
film formed on the first surface 54s of the first flange part 54f is denoted.
[0073] When 1 < Scl/Sel ≤ 1.6, the first roller 56 is weakly pressed toward the first surface
54s of the first flange part 54f. In this case, in an initial stage of an operation
of the rotary compressor 2, an amount of wear of the first surface 54s increases (initial
wear). However, when the operating time exceeds t1, the amount of wear hardly increases
due to an effect of initial adaptability (steady wear). That is, due to sliding between
the first surface 54s and the first roller 56 in the initial stage of the operation,
a contact state between the two is made uniform, and a sliding surface of the first
surface 54s becomes smooth. Thereby, after t1 hour has elapsed, a frictional coefficient
decreases, and the amount of wear is in a state in which it hardly increases.
[0074] On the other hand, in the case of 1.6 < Scl/Sel, the first roller 56 is strongly
pressed toward the first surface 54s. In this case, the amount of wear continues to
increase even when the operating time exceeds t1. That is, the sliding surface has
not been made smooth in the initial stage of the operation of the compressor, and
the effect of initial adaptability cannot be obtained. Particularly, when the refrigerant
of the refrigeration cycle device 1 is carbon dioxide, since the refrigerant is compressed
to a high pressure, an internal pressure of the airtight container 34 increases. Thereby,
since the first roller 56 is strongly pressed toward the first surface 54s, the effect
of initial adaptability cannot be easily obtained.
[0075] As described above, it is desirable that a ratio of the inner pressure receiving
area Sc1 to the outer pressure receiving area Se1 of the first roller 56 satisfy 1
< Scl/Sel ≤ 1.6. Similarly, it is desirable that a ratio of the inner pressure receiving
area Sc2 to the outer pressure receiving area Se2 of the second roller 57 satisfy
1 < Sc2/Se2 ≤ 1.6.
[0076] As described in detail above, in the rotary compressor 2 of the embodiment, the thickness
of the partition plate 53 in the axial direction Z is smaller than the thickness of
the first flange part 54f in the axial direction Z and the thickness of the second
flange part 55f in the axial direction Z. Thereby, a distance between the main bearing
54 and the sub bearing 55 decreases. Accordingly, bending of the shaft 31 between
the main bearing 54 and the sub bearing 55 is suppressed.
[0077] 1 <Sc1/Se1 is established. Thereby, the first roller 56 is pressed against the first
surface 54s of the first flange part 54f. Also, 1 < Sc2/Se2 ≤ 1.6 is established.
Thereby, the second roller 57 is pressed against the second surface 55s of the second
flange part 55f.
[0078] The solid lubricating film 59 is formed on the first surface 54s of the first flange
part 54f and the second surface 55s of the second flange part 55f. Thereby, wear resistance
of the first surface 54s is improved even when the first roller 56 is moved by being
pressed against the first surface 54s. Also, wear resistance of the second surface
55s improves even when the second roller 57 is moved by being pressed against the
second surface 55s.
[0079] Scl/Sel ≤ 1.6 and Sc2/Se2 ≤ 1.6 are established. Thereby, even when the gaseous refrigerant
is compressed to a high pressure, the first roller 56 is weakly pressed against the
first surface 54s of the first flange part 54f. Also, the second roller 57 is weakly
pressed against the second surface 55s of the second flange part 55f. Accordingly,
the effect of initial adaptability can be obtained. Therefore, an amount of wear on
the first surface 54s and the second surface 55s is suppressed. Accordingly, a decrease
in compression performance of the rotary compressor 2 is suppressed.
[0080] The solid lubricating film 59 is preferably a manganese phosphate film or a molybdenum
dioxide film.
[0081] The solid lubricating film 59 preferably includes a manganese phosphate film on the
lower layer and a molybdenum dioxide film on the upper layer.
[0082] Since a manganese phosphate film has excellent wear resistance, reliability of the
rotary compressor 2 is improved. Since the molybdenum dioxide film has a large effect
in reducing initial friction, initial characteristics of the rotary compressor 2 are
improved.
[0083] The gas to be compressed in the rotary compressor 2 is carbon dioxide gas, and the
lubricating oil is a polyalkylene glycol oil.
[0084] When the gas to be compressed is carbon dioxide, it is compressed to a high pressure.
Even in this case, since Scl/Sel ≤ 1.6 and Sc2/Se2 ≤ 1.6 are established, an amount
of wear on the first surface 54s and the second surface 55s is suppressed. Also, a
polyalkylene glycol oil has a smaller decrease in viscosity when it is dissolved than
other lubricating oils. Thereby, a satisfactory lubrication state is maintained even
when the gas to be compressed is compressed to a high temperature. Accordingly, an
amount of wear on the first surface 54s and the second surface 55s is suppressed.
[0085] The refrigeration cycle device 1 of the embodiment includes the rotary compressor
2 described above, the radiator 3 connected to the rotary compressor 2, the expansion
device 4 connected to the radiator 3, and the heat absorber 5 connected to the expansion
device 4.
[0086] In the rotary compressor 2 described above, a decrease in compression performance
is suppressed. Accordingly, a refrigeration cycle device with excellent reliability
is provided.
[0087] According to at least one embodiment described above, 1 < Scl/Sel ≤ 1.6 and 1 < Sc2/Se2
≤ 1.6 are established. Thereby, a decrease in compression performance of the rotary
compressor 2 can be suppressed.
[0088] While certain embodiments have been described, these embodiments have been presented
by way of example only, and are not intended to limit the scope of the inventions.
Indeed, the novel embodiments described herein may be embodied in a variety of other
forms; furthermore, various omissions, substitutions and changes in the form of the
embodiments described herein may be made without departing from the spirit of the
inventions. The accompanying claims and their equivalents are intended to cover such
forms or modifications as would fall within the scope and spirit of the inventions.
[Reference Signs List]
[0089]
- R
- Radial direction
- Z
- Axial direction
- θ
- Circumferential direction
- 1
- Refrigeration cycle device
- 2
- Rotary compressor
- 3
- Radiator
- 4
- Expansion device
- 5
- Heat absorber
- 31
- Shaft
- 33
- Compression mechanism unit
- 34
- Airtight container (container)
- 41
- First eccentric part
- 42
- Second eccentric part
- 51
- First cylinder
- 51a
- First cylinder chamber
- 52
- Second cylinder
- 52a
- Second cylinder chamber
- 53
- Partition plate
- 53h
- Shaft hole
- 54
- Main bearing (first bearing)
- 54f
- First flange part
- 54s
- First surface
- 55
- Sub bearing (second bearing)
- 55f
- Second flange part
- 55s
- Second surface
- 56
- First roller
- 57
- Second roller
- 59
- Solid lubricating film
- 61
- First groove part
- 62
- Second groove part