JP2024070439A - Compressor and refrigeration cycle device - Google Patents

Abstract

To provide a compressor which can inhibit re-expansion loss caused by a discharge communication passage to improve compression efficiency.SOLUTION: A compressor includes: a sealed container; a compression mechanism part; and a drive mechanism part. The compression mechanism part includes: a rotary shaft; a cylinder having a cylinder chamber; a rotor which concentrically rotates with the rotary shaft in the cylinder chamber; and a plurality of vanes which are provided at the rotor and which move forward toward an inner wall surface of the cylinder or rearward in a radial direction of the rotor within the cylinder chamber and define compression chambers in the cylinder chamber. The cylinder chamber has: a minimum gap part which is a gap between the inner wall surface of the cylinder and an outer peripheral surface of the rotor and in which the gap is minimized; and a discharge port which discharges a compressed working fluid. On an axial cross section of the rotary shaft, a contour of the inner wall surface of the cylinder has: a first arc part; a second arc part having a curvature radius smaller than that of the first arc part; and a connection part smoothly connecting the first arc part with the second arc part. The discharge port is open in a range of the second arc part on the inner wall surface of the cylinder.SELECTED DRAWING: Figure 3

Description

An embodiment of the present invention relates to a compressor and a refrigeration cycle device equipped with the compressor.

A rotary compressor used in air conditioners is equipped with a compression mechanism having a cylinder that compresses a refrigerant as a working fluid inside a sealed container. The cylinder has vanes that divide the cylinder chamber, which is the internal space, into a refrigerant suction chamber and a compression chamber, and a discharge port that discharges the compressed refrigerant. There are two types of vanes: those that are provided on the cylinder body side and move forward and backward into the cylinder chamber, and those that are provided on a rotating body (rotor) that rotates concentrically with the rotating shaft inside the cylinder chamber and move forward and backward into the cylinder chamber.

For example, in the case of a sliding vane compressor in which vanes are attached to the rotor, a discharge communication passage with an arc-shaped cross section is provided between the discharge port and the cylinder inner wall surface. This is because the distance between the cylinder inner wall surface and the rotor outer circumferential surface at the discharge port position is small, and if such a discharge communication passage is not provided, flow loss will occur before the compressed refrigerant reaches the discharge port, leading to a deterioration in performance.

JP 2010-209773 A

However, in such discharge communication passages, the refrigerant in the passage is not discharged by the vane, but instead becomes a leakage flow path that crosses the vane as it passes. This increases the re-expansion loss caused by the refrigerant leaking into the suction chamber expanding again in the suction chamber, and there is a risk that performance improvement will be insufficient.

The object of the present invention is to provide a compressor that can suppress re-expansion losses caused by the discharge communication passage and increase compression efficiency.

According to an embodiment, the compressor includes a sealed container, a compression mechanism, and a drive mechanism. The compression mechanism is housed inside the sealed container and compresses the working fluid. The drive mechanism drives the compression mechanism. The compression mechanism includes a rotating shaft connected to the drive mechanism, a cylinder having an annular cylinder chamber that sucks in the working fluid and compresses the sucked working fluid, a rotor having a circular cross-sectional outline in the axial direction of the rotating shaft and rotating concentrically with the rotating shaft in the cylinder chamber, and a plurality of vanes provided on the rotor, which move in the radial direction of the rotor through the cylinder chamber toward the inner wall surface of the cylinder and divide the cylinder chamber into a compression chamber that compresses the working fluid. The cylinder chamber is a gap between the inner wall surface of the cylinder and the outer circumferential surface of the rotor, and has a minimum gap portion where the gap is minimum, and a discharge port that discharges the working fluid compressed in the compression chamber. In the cross section, the contour of the inner wall surface of the cylinder has a first arc portion, a second arc portion having a smaller radius of curvature than the first arc portion, and a connecting portion that smoothly connects the first arc portion and the second arc portion, and the discharge port opens within the range of the second arc portion on the inner wall surface of the cylinder.

FIG. 1 is a circuit diagram that illustrates a schematic configuration of a refrigeration cycle device according to an embodiment. FIG. 2 is a vertical cross-sectional view that illustrates the compressor according to the embodiment. FIG. 3 is a schematic axial cross-sectional view of the cylinder at a location indicated by an arrow B2 in FIG. 2, viewed from the direction of the arrow. FIG. 4 is an axial cross-sectional view showing one form of a cylinder according to a comparative example of the embodiment. FIG. 5 is a diagram showing an axial cross-section of the cylinder at the same location as indicated by arrow B2 in FIG. 2, taken from the direction of the arrow, focusing on the correlation between the first arc portion, the second arc portion, the vane, and the minimum gap portion in the cylinder of the embodiment.

Figure 1 is a refrigeration cycle circuit diagram of an air conditioner 1 according to an embodiment. The air conditioner 1 is a device that performs air conditioning using such a refrigeration cycle, and is an example of a refrigeration cycle device. The air conditioner 1 has, as its main elements, a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor blower 400, an expansion device 5, an indoor heat exchanger 6, and an indoor blower 600.

As shown in FIG. 1, the discharge side of the compressor 2 is connected to a first port 3a of the four-way valve 3. The second port 3b of the four-way valve 3 is connected to an outdoor heat exchanger 4. The outdoor heat exchanger 4 is connected to an indoor heat exchanger 6 via an expansion device 5. The indoor heat exchanger 6 is connected to a third port 3c of the four-way valve 3. The fourth port 3d of the four-way valve 3 is connected to the suction side of the compressor 2 via an accumulator 8.

The refrigerant circulates in a circulation circuit 7 that runs from the discharge side of the compressor 2 through an outdoor heat exchanger 4, an expansion device 5, an indoor heat exchanger 6, and an accumulator 8 to the suction side.
For example, when the air conditioner 1 operates in the cooling mode, the four-way valve 3 switches so that the first port 3a communicates with the second port 3b and the third port 3c communicates with the fourth port 3d. When the air conditioner 1 starts operating in the cooling mode, high-temperature, high-pressure gas-phase refrigerant compressed by the compressor 2 is discharged into the circulation circuit 7. The discharged gas-phase refrigerant passes through the four-way valve 3 and is guided to the outdoor heat exchanger 4, which functions as a condenser (heat radiator).

The gas-phase refrigerant guided to the outdoor heat exchanger 4 condenses through heat exchange with the air (outdoor air) drawn in by the outdoor blower 400, and changes to a high-pressure liquid-phase refrigerant. The high-pressure liquid-phase refrigerant is reduced in pressure as it passes through the expansion device 5, and changes to a low-pressure two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant is guided to the indoor heat exchanger 6, which functions as an evaporator (heat absorber), and exchanges heat with the air (indoor air) drawn in by the indoor blower 600 as it passes through the indoor heat exchanger 6.

As a result, the gas-liquid two-phase refrigerant absorbs heat from the air and evaporates, changing into a low-temperature, low-pressure gas-phase refrigerant. The air passing through the indoor heat exchanger 6 is cooled by the latent heat of evaporation of the liquid-phase refrigerant, and is sent as cold air by the indoor blower 600 to the area to be conditioned (cooled).

The low-temperature, low-pressure gas-phase refrigerant that has passed through the indoor heat exchanger 6 is guided to the accumulator 8 via the four-way valve 3. If the refrigerant contains liquid-phase refrigerant that has not completely evaporated, it is separated into liquid-phase refrigerant and gas-phase refrigerant here. The low-temperature, low-pressure gas-phase refrigerant separated from the liquid-phase refrigerant is sucked from the accumulator 8 into the compressor 2, where it is compressed again into high-temperature, high-pressure gas-phase refrigerant and discharged into the circulation circuit 7.

On the other hand, when the air conditioner 1 operates in heating mode, the four-way valve 3 switches so that the first port 3a communicates with the third port 3c and the second port 3b communicates with the fourth port 3d. When the air conditioner 1 starts operating in heating mode, the high-temperature, high-pressure gas-phase refrigerant discharged from the compressor 2 is guided via the four-way valve 3 to the indoor heat exchanger 6, where it exchanges heat with the air passing through the indoor heat exchanger 6. In this case, the indoor heat exchanger 6 functions as a condenser.

As a result, the gas-phase refrigerant passing through the indoor heat exchanger 6 condenses through heat exchange with the air (indoor air) drawn in by the indoor blower 600, and changes into a high-pressure liquid-phase refrigerant. The air passing through the indoor heat exchanger 6 is heated through heat exchange with the gas-phase refrigerant, and is sent as warm air by the indoor blower 600 to the area to be air-conditioned (heated).

The high-temperature liquid-phase refrigerant that has passed through the indoor heat exchanger 6 is guided to the expansion device 5, and is reduced in pressure during the process of passing through the expansion device 5, changing into a low-pressure two-phase gas-liquid refrigerant. The two-phase gas-liquid refrigerant is guided to the outdoor heat exchanger 4, which functions as an evaporator, and evaporates by exchanging heat with the air (outdoor air) drawn in by the outdoor blower 400, changing into a low-temperature, low-pressure gas-phase refrigerant. The low-temperature, low-pressure gas-phase refrigerant that has passed through the outdoor heat exchanger 4 is sucked into the compressor 2 via the four-way valve 3 and the accumulator 8, and is compressed again by the compressor 2 into a high-temperature, high-pressure gas-phase refrigerant and discharged into the circulation circuit 7.

In this embodiment, the air conditioner 1 can be operated in either cooling mode or heating mode, but the air conditioner 1 may also be, for example, a dedicated cooling or heating machine that can be operated only in either cooling mode or heating mode.

Next, the specific configuration of the compressor 2 used in the air conditioner 1 will be described with reference to FIG. 2. FIG. 2 is a vertical cross-sectional view that shows the compressor 2 in a simplified manner. As shown in FIG. 2, the compressor 2 is a so-called vertical rotary compressor, and includes a sealed container 10, a drive mechanism 11, and a compression mechanism 12 as its main elements. In the following description, the relative positional relationship between the drive mechanism 11 and the compression mechanism 12 aligned along the central axis O1 of the sealed container 10 is used as a reference, with the side where the drive mechanism 11 is located being the top and the side where the compression mechanism 12 is located being the bottom.

The sealed container 10 has a cylindrical peripheral wall 10a and stands vertically relative to the installation surface. The installation surface may be, for example, the bottom plate of an outdoor unit. A discharge pipe 10b is provided at the upper end of the sealed container 10. The discharge pipe 10b is connected to the first port 3a of the four-way valve 3 via the circulation circuit 7. An oil reservoir 10c that stores lubricating oil is provided at the bottom of the sealed container 10.

The drive mechanism 11 is a drive source that drives the compression mechanism 12, or more simply, rotates the rotating shaft 13 described below, and is housed in the middle of the sealed container 10 along the central axis O1 so as to be located between the compression mechanism 12 and the discharge pipe 10b. In the example shown in FIG. 2, the drive mechanism 11 is configured as a so-called inner rotor type, and includes a rotor 11a fixed to the rotating shaft 13 and a stator 11b fixed to the inner surface of the peripheral wall 10a of the sealed container 10.

The rotor 11a is configured with, for example, a cylindrical rotor core fixed concentrically to the rotating shaft 13, and multiple permanent magnets arranged on the rotor core. The rotor 11a is arranged concentrically with the stator 11b, with a small air gap between the rotor 11a and the inner circumference of the stator 11b.

The stator 11b includes, for example, a cylindrical stator core and a winding (coil) wound around the stator core, and is arranged to surround the rotor 11a. When electricity is applied to the coil, the rotor 11a rotates around the central axis O1 relative to the stator 11b, and the rotating shaft 13 rotates together with the rotor 11a.

The compression mechanism 12 is a mechanism that compresses the refrigerant, and is housed in the lower part of the sealed container 10 so that it is immersed in lubricating oil. In the example shown in FIG. 2, the compression mechanism 12 has a rotating shaft 13, a first bearing 14, a second bearing 15, and a cylinder 16 as its main elements.

The rotating shaft 13 stands so that its axis is concentric with the central axis O1 of the sealed container 10, and rotates around the central axis O1 by receiving power from the drive mechanism 11. The rotating shaft 13 is straight and does not have an eccentric part, and is supported rotatably by a first bearing 14 and a second bearing 15. The upper part of the rotating shaft 13 is connected to the rotor 11a of the drive mechanism 11.

In the example shown in FIG. 2, the first bearing 14 is disposed below the cylinder 16 in the axial direction of the rotating shaft 13 (the direction in which the rotating shaft 13 extends). The first bearing 14 has a cylindrical bearing body 14a that rotatably supports the lower end of the rotating shaft 13, and a flange-shaped end plate 14b that extends from one end of the bearing body 14a in the radial direction of the rotating shaft 13. The end plate 14b abuts against the lower surface of the cylinder 16 so as to cover the inner diameter portion of the cylinder 16 from below.

In the example shown in FIG. 2, the second bearing 15 is disposed axially above the cylinder 16. The second bearing 15 has a cylindrical bearing body 15a that rotatably supports the middle part of the rotating shaft 13, and a flange-shaped end plate 15b that extends radially from one end of the bearing body 15a. The end plate 15b abuts against the upper surface of the cylinder 16 so as to cover the inner diameter part of the cylinder 16 from above.

A muffler cover 18 is attached to the second bearing 15. The muffler cover 18 and the second bearing 15 cooperate with each other to define a muffler chamber 19. The muffler chamber 19 opens into the interior of the sealed container 10 through multiple exhaust holes (not shown) in the muffler cover 18.

FIG. 3 is a schematic axial cross-sectional view of the cylinder 16 at a location indicated by an arrow B2 in FIG. 2, viewed from the direction of the arrow.
As shown in Figures 2 and 3, the cylinder 16 has an annular cylinder chamber 31 that draws in a working fluid, in this case a refrigerant, and compresses the drawn refrigerant. The cylinder chamber 31 is defined as a space surrounded by the inner diameter part of the cylinder 16, the first bearing 14, and the second bearing 15. The first bearing 14 corresponds to a closing member that defines the lower surface of the cylinder chamber 31, and the second bearing 15 corresponds to a closing member that defines the upper surface of the cylinder chamber 31. The cylinder 16 has a refrigerant suction passage 32 that opens into a suction chamber 35 of the cylinder chamber 31. A connecting pipe 33 is connected to the suction passage 32. The connecting pipe 33 penetrates the peripheral wall 10a of the sealed container 10, protrudes outside the sealed container 10, and is connected to a suction pipe 10d.

The rotor 23 is accommodated in the cylinder chamber 31. The rotor 23 is an annular member, in other words, the outline of the axial cross section (orthogonal cross section) is a circle concentric with the rotating shaft 13, and is fitted to the outer circumferential surface of the rotating shaft 13 to rotate concentrically with the rotating shaft 13 in the cylinder chamber 31. In this embodiment, as an example, the rotor 23 rotates in the direction indicated by the arrow Ar in FIG. 3. The rotor 23 forms a cylinder chamber 31 between the outer circumferential surface 23a of the rotor 23 and the inner wall surface 16a of the cylinder 16. In other words, the cylinder chamber 31 is defined as the gap between the inner wall surface 16a of the cylinder 16 and the outer circumferential surface 23a of the rotor 23.

The rotor 23 is formed with a plurality of vane slots 24. In this embodiment, as an example, three vane slots 24 are arranged at equal intervals in the circumferential direction as shown in FIG. 3. However, the number of vane slots 24 is not limited to this, and may be two, or may be four or more. Each vane slot 24 houses one vane 25. Each of the three vanes 25 advances and retreats in the cylinder chamber 31 in the radial direction of the rotor 23 toward the inner wall surface 16a of the cylinder 16, and divides the cylinder chamber 31 into a compression chamber 34 that compresses the refrigerant and a suction chamber 35 that sucks in the refrigerant.

The tip 26 of the vane 25 is pressed against the inner wall surface 16a of the cylinder 16 by, for example, the spring elastic force of a spring mechanism (not shown) or centrifugal force generated by the rotation of the rotor 23. When the rotor 23 rotates together with the rotating shaft 13, the tip 26 of the vane 25 slides against the inner wall surface 16a of the cylinder 16. That is, the vane 25 advances and retreats toward the cylinder chamber 31 while sliding the tip 26 against the inner wall surface 16a of the cylinder 16. In contrast, the outer peripheral surface 23a of the rotor 23 does not contact the inner wall surface 16a of the cylinder 16. The cylinder chamber 31 has a minimum gap portion 36 where the gap between the inner wall surface 16a and the outer peripheral surface 23a is the smallest. That is, the cylinder 16 and the rotor 23 are arranged so as to be closest to each other at the minimum gap portion 36.

When the rotor 23 rotates together with the rotating shaft 13, the refrigerant is sucked into the suction chamber 35 from the suction pipe 10d via the connecting pipe 33 and the suction passage 32. The low-temperature, low-pressure gas-phase refrigerant separated from the liquid-phase refrigerant in the accumulator 8 is sucked into the suction chamber 35. When the rotor 23 further rotates and communication with the suction passage 32 is blocked by the vane 25, the suction chamber 35 becomes the compression chamber 34, and the volume of the compression chamber 34 changes as the vane 25 moves back and forth, compressing the refrigerant.

When the high-temperature, high-pressure gas-phase refrigerant compressed in the compression chamber 34 reaches the discharge pressure, it is discharged into the sealed container 10 through the discharge port 28a of the discharge valve mechanism 28. The discharged gas-phase refrigerant rises inside the sealed container 10. Furthermore, during operation of the compression mechanism 12, the lubricating oil (refrigeration oil) stored in the oil reservoir 10c of the sealed container 10 is stirred and becomes mist-like, and rises inside the sealed container 10 toward the discharge pipe 10b along with the flow of the gas-phase refrigerant. The discharge valve mechanism 28 is a valve mechanism for discharging the high-temperature, high-pressure gas-phase refrigerant compressed in the compression chamber 34, and is provided in the cylinder 16. The discharge valve mechanism 28 opens and closes the discharge port 28a with the discharge valve 28b, enabling communication between the compression chamber 34 and the muffler chamber 19. The discharge port 28a opens toward the compression chamber 34 at a predetermined position on the inner wall surface 16a of the cylinder 16.

In the axial cross section of the cylinder 16 shown in FIG. 3, the contour of the inner wall surface 16a is composed of two arc sections of different diameters and a connecting section that smoothly connects these two arc sections. The contour of the inner wall surface 16a is a shape that is drawn by the outline of the inner wall surface 16a in the axial cross section of the inner wall surface 16a. In the example shown in FIG. 3, the contour of the inner wall surface 16a has a first arc section 17a, a second arc section 17b, and a connecting section 17c.

The first arc portion 17a is a portion that continues in an arc shape over a predetermined length with a predetermined radius of curvature (distance R1 shown in FIG. 3). The second arc portion 17b is a portion that continues in an arc shape over a predetermined length with a radius of curvature smaller than that of the first arc portion 17a (distance R2 shown in FIG. 3). In the contour of the inner wall surface 16a, the first arc portion 17a corresponds to a large arc portion with a relatively large radius of curvature (small curvature), and the second arc portion 17b corresponds to a small arc portion with a relatively small radius of curvature (large curvature) (R1>R2). The circumferential length (length continuing in the circumferential direction) of the first arc portion 17a and the circumferential length of the second arc portion 17b are not particularly limited. For example, in the contour of the inner wall surface 16a, the circumferential length of the first arc portion 17a may be about two-thirds to three-quarters, with the remainder being the second arc portion 17b and the connecting portion 17c.

The discharge port 28a opens within the range of the second arc portion 17b of this circumferential length. That is, on the inner wall surface 16a, the discharge port 28a opens within the range of the second arc portion 17b, not the first arc portion 17a and the connection portion 17c.

In addition, in the axial cross section of the cylinder 16 shown in FIG. 3, a minimum gap portion 36 exists within the range of the first arc portion 17a of the circumferential length. That is, the minimum gap portion 36 exists not in the second arc portion 17b and the connecting portion 17c on the inner wall surface 16a, but between the first arc portion 17a and the outer peripheral surface 23a of the rotor 23. In other words, the cylinder chamber 31 has a minimum gap portion 36 between the first arc portion 17a and the outer peripheral surface 23a.

The connecting portion 17c includes a first connecting portion 171c that connects one end of the first arc portion 17a in the circumferential direction to one end of the second arc portion 17b, and a second connecting portion 172c that connects the other end of the first arc portion 17a in the circumferential direction to the other end of the second arc portion 17b. As long as the first arc portion 17a and the second arc portion 17b are smoothly connected, the form (shape and circumferential length) of the connecting portion 17c is not particularly limited. Here, the state in which the first arc portion 17a and the second arc portion 17b are smoothly connected is a state in which no step is generated between the two and the tip portion 25a of the vane 25 can be smoothly slid between the first arc portion 17a and the second arc portion 17b. As an example, in the axial cross section of the cylinder 16 shown in FIG. 3, the connecting portion 17c is a straight line that connects the first arc portion 17a and the second arc portion 17b with a common tangent line.

As a result, the inner wall surface 16a of the cylinder 16 is configured with a continuous series of circumferential surfaces whose axial cross-sectional contours become the first arc portion 17a, the second arc portion 17b, and flat surfaces which become the first connecting portion 171c and the second connecting portion 172c. By making the parts of the inner wall surface 16a of the cylinder 16 which become the first connecting portion 171c and the second connecting portion 172c flat in this way, it becomes easier to machine the circumferential surfaces which become the first arc portion 17a and the second arc portion 17b, and to check the dimensions of these circumferential surfaces after machining.

Thus, according to this embodiment, the discharge port 28a is not in the first arc portion 17a, which is a large arc portion, but in the second arc portion 17b, which is a small arc portion. Therefore, the gap between the inner wall surface 16a of the cylinder 16 and the outer peripheral surface 23a of the rotor 23 at the position of the discharge port 28a can be easily widened. Figure 4 is an axial cross-sectional view showing one form of a cylinder according to a comparative example of this embodiment. In the comparative example shown in Figure 4, a discharge communication passage 300 having an arc-shaped axial cross-sectional profile is provided between the inner wall surface 160a of the cylinder 160 and the outer peripheral surface 230a of the rotor 230 at the position of the discharge port 280a. By providing the discharge communication passage 300, the gap between the inner wall surface 160a and the outer peripheral surface 230a at the position of the discharge port 280a can be widened, but on the other hand, the refrigerant in the passage is not discharged by the vane 250, which is likely to lead to an increase in re-expansion loss.

In contrast, according to this embodiment, as shown in FIG. 3, the contour of the inner wall surface 16a at the second arc portion 17b can be positioned radially outward from the contour of the inner wall surface 160a of the comparative example shown in FIG. 4 (broken line 160a shown in FIG. 3). That is, even without providing a discharge communication passage 300 as in the comparative example, it is possible to widen the gap between the inner wall surface 16a and the outer peripheral surface 23a at the position of the discharge port 28a. This makes it possible to suppress the flow path loss that occurs before the refrigerant compressed in the compression chamber 34 reaches the discharge port 28a. Therefore, it is possible to suppress the re-expansion loss of the refrigerant caused by providing a discharge communication passage 300 as in the comparative example, and to increase the compression efficiency.

In addition, according to this embodiment, the minimum gap portion 36 is between the first arc portion 17a on the inner wall surface 16a and the outer peripheral surface 23a of the rotor 23. The minimum gap portion 36 is a seal portion that seals the refrigerant between the compression chamber 34 and the suction chamber 35 in the cylinder chamber 31, and the smaller the difference between the diameter across the cylinder 16 and the outer diameter of the rotor 23, the higher the sealing performance due to the wedge effect. For this reason, from the viewpoint of sealing performance, it is advantageous for the minimum gap portion (the portion where the gap between the inner wall surface 16a of the cylinder 16 and the outer peripheral surface 23a of the rotor 23 is the smallest) to be between the second arc portion 17b, which is a small arc portion, and the outer peripheral surface 23a of the rotor 23. However, if the minimum gap portion is arranged in this manner corresponding to the second arc portion 17b, the gap between the inner wall surface 16a and the outer peripheral surface 23a at the position of the discharge port 28a becomes small (narrow), which impairs the effect of easily widening the gap as described above. Therefore, by arranging the minimum gap portion 36 between the first arc portion 17a on the inner wall surface 16a and the outer peripheral surface 23a, the sealing performance of the refrigerant can be improved compared to, for example, arranging it corresponding to the connection portion 17c. In addition, the gap between the inner wall surface 16a and the outer peripheral surface 23a at the position of the discharge port 28a can also be enlarged, so that the re-expansion loss of the refrigerant can be suppressed and the compression efficiency can be improved.

In addition, in this embodiment, the cylinder 16 has the following features: Figure 5 is a diagram showing an axial cross section of the cylinder 16 at the same location as the location indicated by the arrow B2 in Figure 2, taken from the direction of the arrow, focusing on the correlation between the first arc portion 17a, the second arc portion 17b, the vane 25, and the minimum gap portion 36 in the cylinder 16 of this embodiment.

In the axial cross section of the cylinder 16 shown in Figure 5, the maximum value (maximum protrusion amount) of the protrusion amount of the vane 25 in the first arc portion 17a is greater than the maximum protrusion amount of the vane 25 in the second arc portion 17b. The protrusion amount of the vane 25 is the length by which the vane 25 protrudes from the outer peripheral surface 23a of the rotor 23 in the radial direction of the rotor 23. In the axial cross section of the cylinder 16 shown in Figure 5, the maximum protrusion amount of the vane 25 in the first arc portion 17a is the protrusion length from the outer peripheral surface 23a when the vane 25 has advanced most far into the cylinder chamber 31 within the range of the first arc portion 17a, and is the length indicated by A1 in Figure 5. In addition, in the cross section of the cylinder 16, the maximum protrusion of the vane 25 in the second arc portion 17b is the protrusion length from the outer circumferential surface 23a when the vane 25 advances furthest into the cylinder chamber 31 within the range of the second arc portion 17b, and is the length indicated by A2 in FIG. 5 (A1>A2).

Here, the protrusion amount of the vane 25 is A, the width of the vane 25 (the length of the vane 25 in the axial direction) is H, the differential pressure applied to the protruding portion of the vane 25 (the portion where the vane 25 protrudes from the outer circumferential surface 23a of the rotor 23 by an amount equivalent to the protrusion amount A) is ΔP, and the lateral pressure applied to the vane 25 is F. The differential pressure ΔP is the difference between the pressures acting on the vane 25 on the leading side and trailing side of the vane 25 when the rotor 23 rotates. In this case, the lateral pressure F of the vane 25 is expressed as F = A x H x ΔP.

In the cylinder chamber 31, the second arc portion 17b of the inner wall surface 16a is closer to the discharge port 28a than the first arc portion 17a, and the refrigerant is more compressed, and the differential pressure ΔP of the vane 25 is also larger. Therefore, if the protrusion amount of the vane 25 increases, the lateral pressure F acting on the vane 25 increases rapidly, causing a deterioration in the reliability of the tip portion 26.

In contrast, in this embodiment, the discharge port 28a opens within the range of the second arc portion 17b of the inner wall surface 16a. Therefore, by making the maximum protrusion amount A1 of the vane 25 in the first arc portion 17a greater than the maximum protrusion amount A2 of the vane 25 in the second arc portion 17b, the vane 25 does not protrude significantly in the range of the second arc portion 17b where the refrigerant is more compressed, and the side pressure F of the vane 25 can be suppressed.

As shown in FIG. 5, the center of curvature Oa of the first arc portion 17a and the center of curvature Ob of the second arc portion 17b are both eccentric from the center of rotation of the rotor 23, that is, the center of rotation O1 of the rotating shaft 13. In the axial cross section of the cylinder 16 shown in FIG. 5, the angle from the minimum gap portion 36 to the end of the second arc portion 17b in the vicinity thereof is θ1, as viewed from the center of rotation of the rotor 23. In addition, in the cross section of the cylinder 16, the angle from the eccentric direction of the first arc portion 17a to the end of the second arc portion 17b in the vicinity thereof is θ2, as viewed from the center of rotation of the rotor 23. In this case, the angle θ1 is smaller than the angle θ2 (θ1<θ2). If the end of the second arc portion 17b that defines the angle θ1 (the connection portion with the first connection portion 171c) is one circumferential end of the second arc portion 17b, then the end of the second arc portion 17b that defines the angle θ2 (the connection portion with the second connection portion 172c) is the other end.

By making angle θ1 smaller than angle θ2 in this way, the gap between the inner wall surface 16a of the cylinder 16 and the outer peripheral surface 23a of the rotor 23 can be increased closer to the minimum gap portion 36 on the discharge port 28a side of the minimum gap portion 36. Therefore, the discharge port 28a can be provided closer to the minimum gap portion 36. This makes it possible to further delay the timing at which the remaining gas in the discharge port 28a after the vane 25 has passed through the discharge port 28a re-expands into the compression chamber 34.

Furthermore, in the axial cross section of the cylinder 16 shown in FIG. 5, the distance between the center of curvature Oa of the first arc portion 17a and the center of curvature Ob of the second arc portion 17b is defined as E1. Also, the distance between the center of curvature Oa of the first arc portion 17a and the center of rotation of the rotor 23 (center of rotation O1 of the rotating shaft 13) is defined as E2. In this case, the distance E1 is equal to or less than the distance E2 (E1≦E2).

When distance E1 is large, the diameter dimension of tip 26 must be made smaller to prevent the corners of tip 26 of vane 25 from contacting inner wall surface 16a of cylinder 16 at both first arc portion 17a and second arc portion 17b. If tip 26 is made smaller, the contact pressure increases at the sliding portion between tip 26 and inner wall surface 16a of cylinder 16, deteriorating reliability. Therefore, by making distance E1 equal to or smaller than distance E2, tip 26 of vane 25 can be kept large.

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the scope of the invention and its equivalents described in the claims.

1...air conditioner, 2...compressor, 3...four-way valve, 4...outdoor heat exchanger, 5...expansion device, 6...indoor heat exchanger, 7...circulation circuit, 8...accumulator, 10...sealed container, 11...drive mechanism, 12...compression mechanism, 13...rotating shaft, 14...first bearing, 15...second bearing, 16...cylinder, 16a...inner wall surface of cylinder, 17a...first arc portion, 17b...second arc portion, 17c...connection portion, 171c...first connection portion, 172c...second connection portion, 23...rotor, 23a...outer peripheral surface of rotor, 24...vane slot, 25...vane, 26...tip of vane, 28...discharge valve mechanism, 28a...discharge port, 31...cylinder chamber, 32...suction passage, 34...compression chamber, 35...suction chamber, 36...maximum Small gap, 400... outdoor blower, 600... indoor blower, A1... maximum protrusion of the vane in the first arc portion, A2... maximum protrusion of the vane in the second arc portion, E1... distance between the center of curvature of the first arc portion and the center of curvature of the second arc portion, E2... distance between the center of curvature of the first arc portion and the center of rotation of the rotor, O1... central axis, Oa... center of curvature of the first arc portion, Ob... center of curvature of the second arc portion, R1... radius of curvature of the first arc portion, R2... radius of curvature of the second arc portion, θ1... angle from the center of rotation of the rotor from the minimum gap to the end of the second arc portion nearby, θ2... angle from the eccentric direction of the first arc portion to the end of the second arc portion nearby, as viewed from the center of rotation of the rotor.

Claims (7)

A sealed container;
a compression mechanism portion that is accommodated inside the sealed container and compresses a working fluid;
A drive mechanism that drives the compression mechanism,
The compression mechanism includes:
A rotating shaft connected to the drive mechanism;
a cylinder having an annular cylinder chamber that draws in the working fluid and compresses the drawn working fluid;
a rotor having a circular cross-sectional profile in an axial direction of the rotary shaft and rotating concentrically with the rotary shaft in the cylinder chamber;
a plurality of vanes provided on the rotor, the vanes moving in a radial direction of the rotor through the cylinder chamber toward an inner wall surface of the cylinder, and defining a compression chamber in the cylinder chamber for compressing the working fluid;
the cylinder chamber is a gap between an inner wall surface of the cylinder and an outer circumferential surface of the rotor, and has a minimum gap portion where the gap is smallest, and a discharge port that discharges the working fluid compressed in the compression chamber,
In the cross section, a contour of the inner wall surface of the cylinder has a first arc portion, a second arc portion having a smaller radius of curvature than the first arc portion, and a connection portion that smoothly connects the first arc portion and the second arc portion, and the discharge port opens within the range of the second arc portion on the inner wall surface of the cylinder. The compressor according to claim 1 , wherein in the cross section, the connection portion forms a straight line connecting the first arc portion and the second arc portion with a same tangent. The vanes protrude from an outer circumferential surface of the rotor and move in and out of the cylinder chamber in a radial direction of the rotor.
2. The compressor according to claim 1, wherein in the cross section, a protruding length from an outer peripheral surface of the rotor when the vane is at its most advanced into the cylinder chamber within the range of the first arc portion is greater than a protruding length from an outer peripheral surface of the rotor when the vane is at its most advanced into the cylinder chamber within the range of the second arc portion. The compressor according to claim 1 , wherein in the transverse cross section, the minimum gap portion is located between an outer circumferential surface of the rotor and the first arc portion. In the cross section, the center of curvature of the first arc portion and the center of curvature of the second arc portion are both eccentric from the center of rotation of the rotor. When viewed from the center of rotation of the rotor, an angle from the minimum gap portion to an end of the second arc portion nearby is defined as θ1, and an angle from the eccentric direction of the first arc portion to an end of the second arc portion nearby is defined as θ2.
θ1<θ2
The compressor according to claim 1 , wherein the following relationship is satisfied: In the cross section, both of the centers of curvature of the first arc portion and the second arc portion are eccentric with respect to the center of rotation of the rotor. When viewed from the center of rotation of the rotor, a distance between the center of curvature of the first arc portion and the center of curvature of the second arc portion is defined as E1, and a distance between the center of curvature of the first arc portion and the center of rotation of the rotor is defined as E2.
E1≦E2
The compressor according to claim 1 , wherein the following relationship is satisfied: A compressor according to any one of claims 1 to 6;
a condenser connected to the compressor;
an expansion device connected to the condenser;
an evaporator connected to the expansion device.

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