Rotary compressors and refrigeration cycle systems
The formation of a recessed flow path with decreasing dimensions around the discharge port in rotary compressors addresses pressure loss issues, enhancing efficiency and maintaining compression performance.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- CARRIER JAPAN CORP
- Filing Date
- 2024-11-13
- Publication Date
- 2026-05-25
AI Technical Summary
The increase in pressure loss during the discharge process in rotary compressors leads to a decrease in compression performance.
A recessed flow path with gradually decreasing width and depth is formed around the discharge port of the cylinder chamber, compensating for the reduction in cross-sectional area and minimizing leakage and pressure loss.
This configuration enhances the efficiency of the rotary compressor by reducing pressure loss and leakage, thereby maintaining or improving compression performance.
Smart Images
Figure 2026085451000001_ABST
Abstract
Description
Technical Field
[0001] Embodiments of the present invention relate to a rotary compressor and a refrigeration cycle device.
Background Art
[0002] In a refrigeration cycle device, a rotary compressor is used to compress a refrigerant. A sliding vane type rotary compressor has a cylinder, a rotor, and a vane. The cylinder has a cylinder chamber. The rotor is disposed inside the cylinder chamber and rotates around a rotation axis eccentric to the cylinder chamber. The vane is disposed in a slit of the rotor, advances and retreats with respect to the cylinder chamber, and divides the cylinder chamber into small chambers. The refrigerant compressed in the small chamber is discharged from a discharge hole formed in the cylinder.
[0003] If the pressure loss increases during the discharge process of the refrigerant, the compression performance of the rotary compressor decreases. There is a need for a rotary compressor and a refrigeration cycle device that can suppress the decrease in compression performance.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
[0007] [Figure 1] Circuit diagram of the refrigeration cycle device and cross-sectional view of the rotary compressor in the embodiment. [Figure 2] Cross-sectional view of the compression mechanism along line II-II in Figure 1. [Figure 3] Developed view of the inner wall surface of the cylinder corresponding to arrow III in Figure 2. [Figure 4] Figure 2 shows a magnified view of the vicinity of the recessed channel, illustrating the first operational diagram. [Figure 5] Figure 2 shows a magnified second diagram illustrating the vicinity of the recessed channel. [Figure 6] Figure 2 shows a magnified view of the vicinity of the recessed channel, illustrating the third operational diagram. [Modes for carrying out the invention]
[0008] The rotary compressor and refrigeration cycle device of the embodiment will be described below with reference to the drawings. Figure 1 includes a circuit diagram of the refrigeration cycle device 1 in an embodiment. The refrigeration cycle device 1 includes a rotary compressor 10, a four-way valve 3, a first heat exchanger 4, an expansion device 5, a second heat exchanger 6, and a refrigerant flow path 8 through which refrigerant (fluid) flows to these components. The refrigerant circulates through the refrigeration cycle device 1 while undergoing phase changes.
[0009] The rotary compressor 10 compresses the low-pressure gaseous refrigerant taken inside into a high-temperature, high-pressure gaseous refrigerant. An accumulator (gas-liquid separator) 2b is located upstream of the rotary compressor 10. The accumulator 2b separates the gaseous and liquid two-phase refrigerant and supplies the gaseous refrigerant to the rotary compressor 10.
[0010] The four-way valve 3 reverses the direction of refrigerant flow in the refrigerant flow path 8 of the first heat exchanger 4, expansion device 5, and second heat exchanger 6. When the four-way valve 3 is in the state shown in Figure 1, the refrigerant discharged from the rotary compressor 10 flows in the order of first heat exchanger 4, expansion device 5, and second heat exchanger 6. At this time, the first heat exchanger 4 functions as a condenser (heat sink), and the second heat exchanger 6 functions as an evaporator (heat absorber). When the four-way valve 3 switches from the state shown in Figure 1, the refrigerant discharged from the rotary compressor 10 flows through the second heat exchanger 6, the expansion device 5, and the first heat exchanger 4 in that order. At this time, the second heat exchanger 6 functions as a condenser (heat radiator), and the first heat exchanger 4 functions as an evaporator (heat absorber).
[0011] The condenser dissipates heat from the high-temperature, high-pressure gaseous refrigerant discharged from the rotary compressor 10, converting the high-temperature, high-pressure gaseous refrigerant into a high-pressure liquid refrigerant. The expansion device 5 reduces the pressure of the high-pressure liquid refrigerant supplied from the condenser, converting the high-pressure liquid refrigerant into a low-temperature, low-pressure gas-liquid two-phase refrigerant. For example, the expansion device 5 is an expansion valve. The evaporator converts the gas-liquid two-phase refrigerant supplied from the expansion device 5 into a low-pressure gaseous refrigerant. In the evaporator, the low-pressure gas-liquid two-phase refrigerant absorbs heat of vaporization from the surroundings as it vaporizes, thus cooling the surroundings. The low-pressure gaseous refrigerant that has passed through the evaporator is taken into the rotary compressor 10 described above via the accumulator 2b.
[0012] In this way, in the refrigeration cycle device 1, the working fluid, the refrigerant, circulates while undergoing a phase change between gas and liquid. The refrigerant releases heat during the phase change from gas to liquid and absorbs heat during the phase change from liquid to gas. The refrigeration cycle device 1 uses the heat release or absorption of the refrigerant to perform heating, cooling, defrosting, etc.
[0013] Figure 1 includes a cross-sectional view of the rotary compressor 10 in an embodiment. Figure 2 is a cross-sectional view of the compression mechanism 20 along the line II-II in Figure 1. In this application, the Z, R, and θ directions of the cylindrical coordinate system are defined as follows: The Z direction is the axial direction of the rotor 16. The +Z direction is the direction from the compression mechanism 20 toward the motor 14. For example, the Z direction is the vertical direction, and the +Z direction is vertically upward. The R direction is the radial direction of the rotor 16. The +R direction is the radially outward direction. The θ direction is the circumferential direction of the rotor 16. The +θ direction (downstream) is the rotational direction of the right-hand screw that advances in the -Z direction. The opposite directions of the +Z, +R, and +θ directions are the -Z, -R, and -θ directions (upstream), respectively.
[0014] The rotary compressor 10 is a sliding vane (rotary vane) type rotary compressor. As shown in Figure 1, the rotary compressor 10 has a case 11, an electric motor unit 14, a shaft 15, and a compression mechanism unit 20.
[0015] The case 11 is formed in a cylindrical shape with both ends closed and sealed. The case 11 houses the motor unit 14, the shaft 15, and the compression mechanism unit 20. Inside the case 11, in the -Z direction, is lubricating oil 12 for lubricating the compression mechanism unit 20. Inside the case 11, in the +Z direction, is the gaseous refrigerant compressed by the compression mechanism unit 20. The gaseous refrigerant and lubricating oil inside the case 11 are under high pressure. The gaseous refrigerant is supplied to the four-way valve 3 from the discharge port 13 in the +Z direction of the case 11 through the refrigerant flow path 8.
[0016] The motor unit 14 is located inside the case 11 in the +Z direction. The motor unit 14 has a stator 14a and a rotor 14b. The stator 14a is fixed to the inner circumferential surface of the case 11. The rotor 14b is located in the -R direction relative to the stator 14a.
[0017] The shaft 15 is arranged coaxially with the case 11. On the +Z direction of the shaft 15, the rotor 14b of the electric motor unit 14 is fixed. On the -Z direction of the shaft 15, the rotor 16 of the compression mechanism unit 20 is fixed. The electric motor unit 14 rotates the rotor 16 via the shaft 15. The shaft 15 and the rotor 16 are separate bodies, but they may also be integrated.
[0018] The compression mechanism unit 20 is arranged in the -Z direction inside the case 11. The compression mechanism unit 20 includes a cylinder 21, a rotor 16, a vane 17 (see FIG. 2), a first bearing 30, a second bearing 35, and a muffler 33.
[0019] The cylinder 21 is arranged coaxially with the case 11. The cylinder 21 is fixed to the inner peripheral surface of the case 11. As shown in FIG. 2, the cylinder 21 has a cylinder chamber 22. The cylinder chamber 22 is formed inside a through hole that penetrates the cylinder 21 in the Z direction. The central axis of the cylinder chamber 22 is eccentric from the central axis of the cylinder 21.
[0020] The rotor 16 is formed in a columnar shape. The rotor 16 is arranged inside the cylinder chamber 22. The space between the outer peripheral surface of the rotor 16 and the inner wall surface of the cylinder 21 functions as a substantial cylinder chamber 22. The rotor 16 is arranged coaxially with the shaft 15. The rotation axis of the rotor 16 coincides with the central axis of the cylinder 21 and is eccentric from the central axis of the cylinder chamber 22.
[0021] [[ID=十六]]The separation distance in the R direction between the outer peripheral surface of the rotor 16 and the inner wall surface of the cylinder 21 (hereinafter simply referred to as the separation distance) varies along the θ direction. In the eccentric direction of the central axis of the cylinder chamber 22 with respect to the central axis of the cylinder 21 (the upward direction in FIG. 2), the separation distance is maximized. In the θ direction, the position where the separation distance is maximized is called the bottom dead center BE. On the other hand, in the opposite direction of the eccentric direction of the central axis of the cylinder chamber 22 (the downward direction in FIG. 2), the separation distance is minimized. In the θ direction, the position where the separation distance is minimized is called the top dead center (minimum separation position) TE.
[0022] In the example shown in Figure 2, there is only one top dead center (TDC) TE in the θ direction. In other words, when the rotor 16 completes one rotation from the TDC TE, the distance between the rotor and TDC simply increases as the rotor 16 passes the bottom dead center (BE), and then the distance between the rotor and TDC simply decreases as the rotor 16 returns to its original TDC TE. There may be multiple TDCs TE in the θ direction.
[0023] As shown in Figure 2, cylinder 21 has a refrigerant intake port (intake passage) 25 and a discharge port (discharge port) 41. The intake port 25 and discharge port 41 penetrate the cylinder 21 in the R direction. The intake port 25 introduces gaseous refrigerant supplied from accumulator 2b (see Figure 1) into the cylinder chamber 22. The discharge port 41 discharges the gaseous refrigerant compressed in the cylinder chamber 22 to the outside of the cylinder chamber 22.
[0024] In the example shown in Figure 2, the rotor 16 rotates in the +θ direction (counterclockwise). In this application, the upstream side (-θ direction) of the rotor 16's rotation direction is sometimes simply referred to as the "upstream side," and the downstream side (+θ direction) of the rotor 16's rotation direction is sometimes simply referred to as the "downstream side." The suction port 25 is located downstream of the top dead center TE of the cylinder chamber 22. The discharge port 41 is located upstream of the top dead center TE of the cylinder chamber 22.
[0025] The vane 17 is formed in a flat plate shape from a metallic material. The vane 17 is positioned in a slit 18 formed in the rotor 16. The slit 18 penetrates the rotor 16 in the Z direction. The slit 18 extends, for example, along the R direction. The +R direction end of the slit 18 opens onto the outer circumferential surface of the rotor 16. A back pressure chamber 19 is formed at the -R direction end of the slit 18. High-pressure lubricating oil 12 (see Figure 1) enters the back pressure chamber 19. The pressure of the lubricating oil 12 in the back pressure chamber 19 acts on the vane 17. In addition, centrifugal force acts on the vane 17 as the rotor 16 rotates. The vane 17 is pressed against the inner wall surface of the cylinder 21 by the pressure of the lubricating oil 12 in the back pressure chamber 19 and the centrifugal force. The vane 17 moves back and forth relative to the cylinder chamber 22 as the rotor 16 rotates.
[0026] Multiple vanes 17 are arranged at equal angular intervals in the θ direction. The multiple vanes 17 divide the cylinder chamber 22 into multiple small chambers (working chambers) 23 in the θ direction. As the rotor 16 rotates, the small chambers 23 move in the +θ direction. When the small chambers 23 move from top dead center TE to bottom dead center BE, the volume of the small chambers 23 increases. The small chambers 23, which communicate with the suction port 25, draw in gaseous refrigerant from the suction port 25 as the volume increases. When the small chambers 23 move from bottom dead center BE to top dead center TE, the volume of the small chambers 23 decreases. The small chambers 23 compress the gaseous refrigerant as the volume decreases. High-pressure gaseous refrigerant is discharged from the discharge port 41. In Figure 2, the small chamber 23 facing the discharge port 41 is designated as the first small chamber 23a, the small chamber 23 adjacent to the upstream side of the first small chamber 23a is designated as the second small chamber 23b, and the small chamber 23 adjacent to the upstream side of the second small chamber 23b and to the downstream side of the first small chamber 23a is designated as the third small chamber 23c. The third small chamber 23c faces the intake passage.
[0027] For each rotation of the rotor 16, the gaseous refrigerant is drawn in and discharged a predetermined number of times. The predetermined number of times corresponds to the number of vanes 17. In the example in Figure 2, there are three vanes 17, but there may be two or fewer vanes 17, or four or more vanes 17. In Figure 2, the vane located at the downstream end of the first chamber 23a is designated as the first vane, the vane located at the upstream end of the first chamber 23a is designated as the second vane, and the vane located upstream of the second vane and downstream of the first vane is designated as the third vane.
[0028] In a sliding vane type rotary compressor 10, the rotor 16 rotates coaxially with the shaft 15. This rotary compressor 10 is low-cost, low-vibration, and low-noise. In this rotary compressor 10, the cylinder chamber 22 is divided into multiple small chambers 23 by multiple vanes 17. The volumetric flow rate per section is reduced, and suction and discharge pulsations are reduced. In this rotary compressor 10, the vanes 17 are located on the rotor 16 and not on the cylinder 21. The inner diameter of the cylinder chamber 22 is increased, the exhaust volume is increased, and the compression performance of the rotary compressor 10 is improved.
[0029] As shown in Figure 1, a first bearing (main bearing) 30 is positioned in the +Z direction of the cylinder 21. The first bearing 30 has a bearing portion 31 and a closing portion 32. The bearing portion 31 of the first bearing 30 rotatably supports the shaft 15 of the cylinder 21 in the +Z direction. The closing portion 32 of the first bearing 30 closes the opening of the cylinder chamber 22 in the +Z direction.
[0030] A second bearing (sub-bearing) 35 is positioned in the -Z direction of the cylinder 21. The second bearing 35 has a bearing portion 36 and a closing portion 37. The bearing portion 36 of the second bearing 35 rotatably supports the shaft 15 of the cylinder 21 in the -Z direction. The closing portion 37 of the second bearing 35 closes the opening of the cylinder chamber 22 in the -Z direction.
[0031] A muffler 33 is positioned in the +Z direction of the closed portion 32 of the first bearing 30. A muffler chamber 34 is formed between the muffler 33 and the first bearing 30. The muffler chamber 34 contains the high-pressure gaseous refrigerant discharged from the discharge hole 41 of the cylinder 21. The high-pressure gaseous refrigerant is discharged into the case 11 through the opening between the bearing portion 31 of the first bearing 30 and the muffler 33.
[0032] The discharge port 41 will be explained with reference to Figures 2 and 3. As shown in Figure 2, the discharge hole 41 is formed on the inner wall surface of the cylinder 21. The discharge hole 41 is formed in the center of the cylinder 21 in the Z direction. When viewed from the R direction, the discharge hole 41 is, for example, circular in shape. In the example shown in Figure 2, there is one discharge port 41, but there may be two or more (multiple) discharge ports 41.
[0033] The discharge port 41 is located upstream of the top dead center TE. The discharge port 41 extends in the +R direction from the inner wall surface of the cylinder 21 and communicates with the communication passage 34a. The communication passage 34a extends in the +Z direction inside the cylinder 21 and communicates with the muffler chamber 34 (see Figure 1). The discharge port 41 is open to the communication passage 34a and the muffler chamber 34 outside the cylinder chamber 22.
[0034] The cylinder 21 has a recessed flow path 28 on its inner wall surface. The recessed flow path 28 is formed at the opening of the discharge hole 41 on the cylinder chamber 22 side. The recessed flow path 28 is formed in the center of the cylinder 21 in the Z direction. As shown in Figure 3, the recessed channel 28 has, for example, an elliptical shape when viewed from the R direction. The recessed channel 28 forms a shallow hemispherical inner surface. Details of the recessed channel 28 will be described later.
[0035] A reed valve 42 is positioned at the opening of the discharge port 41 opposite to the cylinder chamber 22. As shown in Figure 2, the reed valve 42 is made of a metal plate. The reed valve 42 is located inside the muffler chamber 48. The reed valve 42 has an opening / closing section 43, a fixed section 45, and an intermediate section 44. The opening / closing section 43 opens and closes the discharge hole 41. When viewed from the R direction, the outer shape of the opening / closing section 43 is larger than the discharge hole 41. The fixed section 45 fixes the reed valve 42 to the cylinder 21 with bolts or the like. The intermediate section 44 is located between the opening / closing section 43 and the fixed section 45 in the θ direction and connects the two. The intermediate section 44 is elastically deformable from a flat state to a curved state. When the intermediate section 44 is curved, the opening / closing section 43 moves in the +R direction, and the discharge hole 41 moves to an open state (referred to as the open state). When the intermediate section 44 returns to a flat state, the opening / closing section 43 moves in the -R direction, and the discharge hole 41 moves to a closed state (referred to as the closed state). A regulating member 46 is positioned in the +R direction of the reed valve 42. The regulating member 46 restricts excessive movement of the reed valve 42 in the +R direction.
[0036] As shown in Figure 3, the recessed channel 28 is, for example, elliptical when viewed from the R direction. The recessed channel 28 forms a shallow hemispherical inner surface. The depth of the recessed channel 28 gradually increases smoothly from the upstream end P1 to the central part P2 in the θ direction, and gradually decreases smoothly from the central part P2 in the θ direction to the downstream end. The central part P2 in the θ direction is the maximum cross-sectional position of the recessed channel 28. The width of the recessed channel 28 in the axial direction (Z direction) gradually increases smoothly from the upstream end P1 to the central part P2 in the θ direction, and gradually decreases smoothly from the central part P2 in the θ direction to the downstream end. The upstream end P3 of the discharge hole 41 is located at the central part P2 in the θ direction of the recessed channel 28. That is, the recessed channel 28 is formed with an offset to the upstream side relative to the discharge hole 41.
[0037] The term "hemispherical" is not limited to a spherical shape with a constant radius, but may also refer to an irregularly shaped sphere in which the radius gradually changes in at least one of the circumferential direction (θ direction) and radial direction (R direction) of the cylinder 21 (including an elliptical shape as well as an irregularly shaped circular shape that is asymmetrical with respect to the minor or major axis when viewed from the radial direction of the cylinder 21).
[0038] Figures 4 to 6 are enlarged views of the vicinity of the recessed channel 28 in Figure 2. Figure 4 shows the state where the first vane 17a has reached the upstream end of the recessed channel 28, Figure 5 shows the state where the first vane 17a is on the upstream side of the recessed channel 28, and Figure 6 shows the state where the first vane 17a has reached the maximum cross-sectional position of the recessed channel 28.
[0039] As shown in Figures 4 to 6, the cross-section of the cylinder chamber 22 between the outer circumferential surface of the rotor 16 and the inner wall surface of the cylinder 21 is defined as the flow path cross-section of the cylinder chamber 22. The flow path cross-section of the cylinder chamber 22 is the cross-section of the cylinder chamber 22 along the plane containing the rotation axis of the rotor 16. The area of the flow path cross-section of the cylinder chamber 22 is defined as the flow path cross-sectional area A1. The recessed flow path 28 gradually and smoothly reduces the flow path cross-sectional area A1 of the cylinder chamber 22 from the upstream side of the discharge hole 41 to the inlet of the discharge hole 41. The recessed flow path 28 allows the refrigerant from the cylinder chamber 22 to be introduced into the discharge hole 41.
[0040] In this embodiment, the flow path cross-section of the recessed flow path 28 (a cross-section on the same plane as the flow path cross-section of the cylinder chamber 22) is added to the flow path cross-section of the cylinder chamber 22. The area of the flow path cross-section of the recessed flow path 28 is denoted as the flow path cross-sectional area A2.
[0041] As the cylinder chamber 22 approaches the discharge port 41 in the +θ direction, the flow path cross-sectional area A1 of the cylinder chamber 22 decreases. This decrease is compensated for by the flow path cross-sectional area A2 of the recessed flow path 28, thereby suppressing the increase in flow path loss (pressure loss). When the first vane 17a passes over the upstream end of the recessed flow path 28, it becomes a connecting flow path that connects the first small chamber 23a and the discharge port 41. Such a connecting flow path becomes a leakage flow path that allows refrigerant, before it is sufficiently compressed in the first small chamber 23a, to escape to the discharge port 41 side by crossing the first vane 17a. In this embodiment, the shape of the recessed flow path 28 is set as follows in order to reduce the cross-sectional area of the portion that becomes a leakage flow path.
[0042] The recessed flow path 28 extends a flow path communicating with the discharge hole 41 in the circumferential direction (θ direction) of the cylinder 21. Upstream of the discharge hole 41 (-θ direction), the recessed flow path 28 gradually decreases both its width H and depth T as it moves upstream. The recessed flow path 28 compensates for the decrease in the flow path cross-sectional area A1 of the cylinder chamber 22, thereby suppressing flow loss. Upstream of the recessed flow path 28 (upstream of the central part P2 in the θ direction), the width H and depth T gradually decrease, so when the first vane 17a reaches the upstream end of the recessed flow path 28, there is less refrigerant leakage, and the impact on compression performance can be suppressed.
[0043] To completely discharge the refrigerant from the small chamber, the discharge port 41 should be close to the top dead center (TDC). However, if the discharge port 41 is too close to TDC, the flow path cross-section of the cylinder chamber 22 becomes too narrow, increasing flow path losses. In this embodiment, the discharge port 41 is located near TDC but shifted upstream of TDC. Furthermore, a recessed flow path 28 is formed at the opening of the discharge port 41 on the cylinder chamber 22 side. This suppresses the increase in flow path losses caused by the narrowing of the flow path cross-section of the cylinder chamber 22.
[0044] The operation of the compression mechanism 20 will now be described. The state shown in Figure 2 is when the first vane 17a has just passed the discharge hole 41 (the first vane 17a is at top dead center TE), and the second vane 17b is located upstream of the discharge hole 41. The first small chamber 23a is in communication with the discharge hole 41. Here, the minimum pressure in the first chamber 23a required for the reed valve 42 to open the discharge port 41 is defined as the first discharge pressure. In the state shown in Figure 2, the refrigerant pressure in the first chamber 23a is less than the minimum discharge pressure.
[0045] As the rotor 16 rotates further from the state shown in Figure 2, the first chamber 23a shrinks, and the refrigerant pressure in the first chamber 23a increases. When the refrigerant pressure in the first chamber 23a reaches the minimum discharge pressure, the reed valve 42 opens the discharge port 41. When the discharge port 41 transitions from the closed state to the open state, the refrigerant in the first chamber 23a is discharged from the discharge port 41. As the rotor 16 rotates further and the second vane 17b reaches the vicinity of the discharge port 41, almost all of the refrigerant in the first small chamber 23a is discharged from the discharge port 41.
[0046] Downstream of the first vane 17a in Figure 2, the third small chamber 23c, formed between the first vane 17a and the third vane 17c, expands in volume as it draws in refrigerant from the intake passage. The second small chamber 23b, formed between the second vane 17b and the third vane 17c in Figure 2, is in a state where refrigerant intake is complete. The second small chamber 23b reaches downstream of the bottom dead center BE and begins to compress the refrigerant. The compression mechanism 20 repeatedly performs the above-mentioned suction, compression, and discharge of the refrigerant in the first chamber 23a, the second chamber 23b, and the third chamber 23c while the rotor 16 rotates.
[0047] The flow path cross-sectional area A1 of the cylinder chamber 22 decreases from the bottom dead center BE to the top dead center TE. The discharge port 41 is located near the top dead center TE. During the process of refrigerant flowing from the cylinder chamber 22 to the discharge port 41, pressure loss (sometimes called flow path loss) occurs due to flow resistance.
[0048] In the rotary compressor 10 of this embodiment, a recessed flow path 28 is formed at the inlet (opening) of the discharge hole 41 on the cylinder chamber 22 side. The recessed flow path 28 is a recess having a hemispherical inner surface, and its width dimension H and depth dimension T are gradually changed. The central part P2 in the θ direction of the recessed flow path 28 is the maximum cross-sectional position of the recessed flow path 28. The discharge hole 41 opens downstream of the maximum cross-sectional position of the recessed flow path 28. The upstream end of the circular opening of the discharge hole 41 is at the maximum cross-sectional position of the recessed flow path 28. Upstream of the maximum cross-sectional position of the recessed flow path 28, the width dimension H and depth dimension T gradually decrease as you move upstream.
[0049] As shown in Figure 4, when the first vane 17a reaches the upstream end of the recessed flow path 28, the flow path cross-sectional area A1 of the cylinder chamber 22 becomes small, which may increase the flow resistance. As shown in Figure 5, when the first vane 17a passes the upstream end of the recessed flow path 28, the first small chamber 23a and the recessed flow path 28 are connected, and the flow path cross-sectional area A2 of the recessed flow path 28 is added to the flow path cross-sectional area A1 of the cylinder chamber 22. By compensating for the decrease in flow path area due to the reduction in the flow path cross-sectional area A1 of the cylinder chamber 22 with the flow path cross-sectional area A2 of the recessed flow path 28, the increase in flow path loss is suppressed.
[0050] In this case, the recessed passage 28 becomes a communication passage (leakage passage) that connects the first small chamber 23a and the discharge hole 41, and the shape of the recessed passage 28 is set to reduce the cross-sectional area of this leakage passage. As mentioned above, the recessed passage 28 gradually decreases in both its width H and depth T as it moves upstream from the discharge hole 41 (-θ direction). This reduces refrigerant leakage when the first vane 17a enters the recessed passage 28, thereby minimizing the impact on compression performance.
[0051] As shown in Figure 6, when the first vane 17a reaches the maximum cross-sectional position of the recessed flow path 28, the sum of the flow path cross-sectional area A1 of the cylinder chamber 22 and the flow path cross-sectional area A2 of the recessed flow path 28 (maximum flow path cross-sectional area A2M) is the same as the flow path cross-sectional area A3 of the discharge hole 41. The decrease in the flow path cross-sectional area A1 of the cylinder chamber 22 is compensated for by the flow path cross-sectional area A2 of the recessed flow path 28, and the cross-sectional area of the leakage flow path is made as small as possible. It is preferable that the cross-sectional area at the maximum cross-sectional position of the recessed flow path 28 (maximum flow path cross-sectional area A2M) is smaller than the flow path cross-sectional area A3 of the discharge hole 41.
[0052] The recessed flow path 28 helps to reduce flow loss during the process of refrigerant flowing from the cylinder chamber 22 to the discharge port 41. By keeping the cross-sectional area of the leakage flow path when passing through the vane upstream of the recessed flow path 28 small, the decrease in the compression efficiency of the rotary compressor 10 can be suppressed.
[0053] As described above, the rotary compressor 10 of the embodiment includes a cylinder 21, a rotor 16, and vanes 17. The cylinder 21 has a cylinder chamber 22. The rotor 16 is positioned inside the cylinder chamber 22 and rotates around a rotation axis that is eccentric with respect to the cylinder chamber 22. The vanes 17 are positioned in slits 18 of the rotor 16 and move forward and backward relative to the cylinder chamber 22 as the rotor 16 rotates, dividing the cylinder chamber 22 into a plurality of small chambers 23. The cylinder 21 has a discharge hole 41 for discharging the fluid compressed in the small chambers 23 to the outside of the cylinder chamber 22. A recessed flow path 28 is formed around the opening of the discharge hole 41 to the cylinder chamber 22. As the recessed flow path 28 moves upstream of the discharge hole 41 in the direction of rotation of the rotor 16 (rotor rotation direction) θ, both the width dimension H and the depth dimension T of the recessed flow path 28 gradually decrease.
[0054] With this configuration, a recessed flow path 28 is formed around the opening of the discharge hole 41 to the cylinder chamber 22. This makes it possible to more efficiently compensate for the reduced space formed between the inner wall surface of the cylinder 21 (cylinder inner wall surface) and the outer circumferential surface of the rotor 16 (rotor outer circumferential surface) of the discharge flow path by increasing the cross-sectional area of the discharge flow path. On the other hand, as the recessed channel 28 moves upstream in the rotor rotation direction θ, both its width H and depth T are reduced, making it easy and reliable to reduce the leakage channel cross-section when the vane passes upstream of the recessed channel 28. Through the above mechanisms, it is possible to provide a highly efficient compressor that suppresses pressure loss and leakage loss, thereby minimizing the reduction in compression performance.
[0055] In the rotary compressor 10 of this embodiment, the maximum flow path cross-sectional area A2M of the recessed flow path 28 is smaller than the flow path cross-sectional area A3 of the discharge hole 41. With this configuration, since the maximum flow path cross-sectional area A2M of the recessed flow path 28 is smaller than the flow path cross-sectional area of the discharge hole 41, a sufficient discharge flow path can be obtained while suppressing an increase in leakage loss. In other words, if the cross-sectional area of the recessed flow path 28 is made too large, the leakage flow path cross-sectional area when passing through the vane will also increase, and the compression performance will decrease due to increased leakage loss. The discharge flow path is formed by the space formed by the inner wall surface of the cylinder and the outer surface of the rotor, and the recessed flow path 28, and the sum of these cross-sectional areas should be equal to the flow path cross-sectional area of the discharge hole 41. Therefore, by making the maximum flow path cross-sectional area A2M of the recessed flow path 28 smaller than the flow path cross-sectional area of the discharge hole 41, a sufficient discharge flow path can be obtained while suppressing an increase in leakage loss.
[0056] In the rotary compressor 10 of this embodiment, the recessed flow path 28 is a recess having a hemispherical inner wall surface. With this configuration, the recessed channel 28 is a recess with a hemispherical inner wall surface, so the recessed channel 28 can be easily formed using a cutting tool with a spherical tip, such as a ball end mill. Therefore, a compressor with high manufacturability can be provided.
[0057] The refrigeration cycle device 1 of this embodiment includes the rotary compressor 10 described above, one of the first heat exchanger 4 and the second heat exchanger 6 which functions as a radiator, an expansion device 5, and the other of the first heat exchanger 4 and the second heat exchanger 6 which functions as a heat absorber. The radiator is connected to the rotary compressor 10. The expansion device 5 is connected to the radiator. The heat absorber is connected to the expansion device 5. In the rotary compressor 10 described above, the decrease in the compression performance of the refrigerant is suppressed. By having this rotary compressor 10, a high-performance refrigeration cycle device 1 can be provided.
[0058] According to at least one embodiment described above, the system comprises a cylinder 21, a rotor 16, and vanes 17. A recessed flow path 28 is formed on the cylinder chamber 22 side of the discharge hole 41 of the cylinder 21. As the recessed flow path 28 moves upstream of the discharge hole 41 in the rotor rotation direction θ, both the width dimension H and the depth dimension T of the recessed flow path 28 are gradually reduced. This compensates for the decrease in the cross-sectional area of the discharge flow path and suppresses a decrease in compression performance.
[0059] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents. [Explanation of Symbols]
[0060] 1...Refrigeration cycle unit, 4...First heat exchanger (radiator, heat absorber), 5...Expansion device, 6...Second heat exchanger (heat absorber, heat absorber), 10...Rotary compressor, 16...Rotor, 17...Vane, 18...Slit, 21...Cylinder, 22...Cylinder chamber, 23...Small chamber, 28...Recessed flow path, 41...Discharge port, 42...Reed valve, θ...Rotor rotation direction, H...Width dimension, T...Depth dimension, A2M...Maximum flow path cross-sectional area of the recessed flow path, A3...Flow path cross-sectional area of the discharge port
Claims
1. A cylinder having a cylinder chamber, A rotor is disposed inside the cylinder chamber and rotates around a rotation axis that is eccentric with respect to the cylinder chamber, The rotor has vanes arranged in the slits, which move forward and backward relative to the cylinder chamber as the rotor rotates, dividing the cylinder chamber into a plurality of small chambers. The cylinder has a discharge port for discharging the fluid compressed in the small chamber to the outside of the cylinder chamber. A recessed flow path is formed around the opening of the discharge hole to the cylinder chamber. The recessed flow channel gradually decreases in both its width and depth as it moves upstream from the discharge hole in the rotor rotation direction. Rotary compressor.
2. The maximum cross-sectional area of the recessed channel is smaller than the cross-sectional area of the discharge hole. The rotary compressor according to claim 1.
3. The recessed channel is a recess having a hemispherical inner wall surface. The rotary compressor according to claim 1.
4. A rotary compressor according to any one of claims 1 to 3, A heat sink connected to the rotary compressor, An expansion device connected to the heat sink, The expansion device has a heat absorber connected to it, Refrigeration cycle device.