Rotary compressors and refrigeration cycle systems

Abstract

The objective is to provide a rotary compressor and refrigeration cycle device that can suppress the deterioration of compression performance. [Solution] The rotary compressor of this embodiment comprises a cylinder, a rotor, and vanes. The cylinder has a cylinder chamber. The rotor is located inside the cylinder chamber and rotates around a rotation axis eccentric to the cylinder chamber. The vanes are located in slits of the rotor and move forward and backward relative to the cylinder chamber as the rotor rotates, dividing the cylinder chamber into smaller chambers. The cylinder has a first discharge port and a second discharge port for discharging the fluid compressed in the smaller chambers to the outside of the cylinder chamber. The second discharge port is located upstream of the first discharge port in the direction of rotor rotation. The rotary compressor further comprises a first reed valve located outside the cylinder chamber for opening and closing the first discharge port and a second reed valve for opening and closing the second discharge port.

Description

Technical Field

[0001] Embodiments of the present invention relate to a rotary compressor and a refrigeration cycle apparatus.

Background Art

[0002] In a refrigeration cycle apparatus, a rotary compressor is used to compress a refrigerant. A sliding vane type rotary compressor includes 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 rotating shaft eccentric with respect 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 apparatus capable of suppressing the decrease in compression performance.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a rotary compressor and a refrigeration cycle apparatus capable of suppressing a decrease in compression performance.

Means for Solving the Problems

[0006] The rotary compressor of Embodiment 1 comprises a cylinder, a rotor, and vanes. The cylinder has a cylinder chamber. The rotor is located inside the cylinder chamber and rotates around a rotation axis eccentric to the cylinder chamber. The vanes are located in slits of the rotor and move forward and backward relative to the cylinder chamber as the rotor rotates, dividing the cylinder chamber into smaller chambers. The cylinder has a first discharge port and a second discharge port for discharging the fluid compressed in the smaller chambers to the outside of the cylinder chamber. The second discharge port is located upstream of the first discharge port in the direction of rotor rotation. The rotary compressor further comprises a first reed valve located outside the cylinder chamber for opening and closing the first discharge port and a second reed valve for opening and closing the second discharge port.

[0007] The rotary compressor of Embodiment 2 is based on the rotary compressor described in Embodiment 1. The plate thickness of the second reed valve is thicker than the plate thickness of the first reed valve.

[0008] The rotary compressor of Embodiment 3 is based on the rotary compressor described in Embodiment 1 or 2. The flow path cross-sectional area of ​​the second discharge port is larger than the flow path cross-sectional area of ​​the first discharge port.

[0009] The rotary compressor of Embodiment 4 is based on the rotary compressor described in any one of Embodiments 1 to 3. The natural frequency of the second reed valve is greater than the natural frequency of the first reed valve.

[0010] The rotary compressor of Embodiment 5 is based on the rotary compressor described in any one of Embodiments 1 to 4. The spring constant of the first reed valve is smaller than the spring constant of the second reed valve.

[0011] The rotary compressor of embodiment 6 is based on the rotary compressor described in any one of embodiments 1 to 5. The first fixing part for fixing the first reed valve to the cylinder is positioned downstream of the first discharge port in the direction of rotor rotation. The second fixing part for fixing the second reed valve to the cylinder is positioned upstream of the second discharge port. The minimum separation position is defined as the position where the distance between the outer surface of the rotor and the inner wall surface of the cylinder is minimized in the direction of rotor rotation. The first discharge port is positioned upstream of the minimum separation position, and the first fixing part is positioned downstream of the minimum separation position.

[0012] The rotary compressor of Embodiment 7 is based on the rotary compressor described in Embodiment 6. The minimum pressure in the chamber where the first reed valve opens the first discharge port is defined as the first discharge pressure. The minimum pressure in the chamber where the second reed valve opens the second discharge port is defined as the second discharge pressure. The smaller of the first discharge pressure and the second discharge pressure is defined as the minimum discharge pressure. After the chamber reaches the minimum discharge pressure, the first rotation angle range of the rotor in which the chamber communicates with both the first and second discharge ports is greater than the second rotation angle range of the rotor in which the chamber communicates with only the first discharge port.

[0013] The rotary compressor of Embodiment 8 is based on the rotary compressor described in any one of Embodiments 1 to 7. The cross-section of the cylinder chamber between the outer circumferential surface of the rotor and the inner wall surface of the cylinder, along the plane containing the axis of rotation, is defined as the flow path cross-section of the cylinder chamber. Let A1 be the flow path cross-sectional area of ​​the cylinder chamber at the upstream end of the second discharge port. Let A2 be the flow path cross-sectional area of ​​the second discharge port. Let A3 be the flow path cross-sectional area of ​​the cylinder chamber at the upstream end of the first discharge port. The relationship A1 > A2 > A3 holds true.

[0014] The rotary compressor of embodiment 9 is based on the rotary compressor described in any one of embodiments 1 to 8. The cylinder has a first muffler chamber formed outside the cylinder chamber on either side of a first discharge hole and a second muffler chamber formed outside the cylinder chamber on either side of a second discharge hole. The volume of the second muffler chamber is greater than the volume of the first muffler chamber.

[0015] The refrigeration cycle device of the embodiment includes a rotary compressor, a radiator, an expansion device, and a heat absorber, as described in any one of embodiments 1 to 9. The radiator is connected to the rotary compressor. The expansion device is connected to the radiator. The heat absorber is connected to the expansion device. [Brief explanation of the drawing]

[0016] [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 portion taken along line II-II in FIG. 1. [Figure 3] First operation explanatory diagram of the compression mechanism portion. [Figure 4] Second operation explanatory diagram of the compression mechanism portion. [Figure 5] Third operation explanatory diagram of the compression mechanism portion. [Figure 6] Enlarged view of the periphery of the first discharge hole and the second discharge hole.

Mode for Carrying Out the Invention

[0017] Hereinafter, the rotary compressor and the refrigeration cycle device of the embodiment will be described with reference to the drawings. FIG. 1 includes a circuit diagram of the refrigeration cycle device 1 in the embodiment. The refrigeration cycle device l has 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 for circulating a refrigerant (fluid) through these components. The refrigerant circulates through the refrigeration cycle device 1 while undergoing a phase change.

[0018] The rotary compressor 10 compresses the low-pressure gaseous refrigerant taken into it to a high-temperature and high-pressure gaseous refrigerant. An accumulator (gas-liquid separator) lb is disposed upstream of the rotary compressor 10. The accumulator 2b separates the gas-liquid two-phase refrigerant and supplies the gaseous refrigerant to the rotary compressor 1O.

[0019] The four-way valve 3 reverses the flow direction of the refrigerant in the refrigerant flow paths 8 of the first heat exchanger 4, the expansion device 5, and the second heat exchanger 6. When the four-way valve 3 is in the state shown in FIG. 1, the refrigerant discharged from the rotary compressor 10 flows through the first heat exchanger 4, the expansion device 5, and the second heat exchanger 6 in that order. At this time, the first heat exchanger 4 functions as a condenser (radiator), and the second heat exchanger 6 functions as an evaporator (heat absorber). When the four-way valve 3 is switched from the state shown in FIG. 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 (radiator), and the first heat exchanger 4 functions as an evaporator (heat absorber).

[0020] The condenser dissipates heat from the high-temperature and high-pressure gaseous refrigerant discharged from the rotary compressor 10 to convert the high-temperature and high-pressure gaseous refrigerant into a high-pressure liquid refrigerant. The expansion device 5 reduces the pressure of the high-pressure liquid refrigerant fed from the condenser to convert the high-pressure liquid refrigerant into a low-temperature and 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 fed from the expansion device 5 into a low-pressure gaseous refrigerant. In the evaporator, when the low-pressure gas-liquid two-phase refrigerant vaporizes, it absorbs the heat of vaporization from the surroundings, thereby cooling the surroundings. The low-pressure gaseous refrigerant that has passed through the evaporator is taken into the interior of the above-described rotary compressor 10 via the accumulator 2b.

[0021] Thus, in the refrigeration cycle device 1, the refrigerant, which is the working fluid, circulates while undergoing a phase change between gas and liquid. The refrigerant dissipates heat during the process of changing from gas to liquid and absorbs heat during the process of changing from liquid to gas. The refrigeration cycle device 1 performs heating, cooling, defrosting, etc. by utilizing the heat dissipation or heat absorption of the refrigerant.

[0022] FIG. 1 includes a cross-sectional view of the rotary compressor 10 in the embodiment. FIG. 2 is a cross-sectional view of the compression mechanism portion 20 taken along the line II-II of FIG. 1. In the present application, the Z direction, R direction, and θ direction in 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 portion 20 toward the motor portion 14. For example, the Z direction is the vertical direction, and the +Z direction is the vertically upward direction. The R direction is the radial direction of the rotor 16. The +R direction is the direction toward the outside in the radial direction. The θ direction is the circumferential direction of the rotor 16. The +θ direction (downstream side) is the clockwise rotation direction advancing in the -Z direction. Note that the opposite directions of the +Z direction, +R direction, and +θ direction are the -Z direction, -R direction, and -θ direction (upstream side), respectively.

[0023] The rotary compressor 10 is a sliding vane (rotary vane) type rotary compressor. As shown in FIG. 1, the rotary compressor 10 includes a case 11, a motor portion 14, a shaft 15, and a compression mechanism portion 20.

[0024] The case 11 is formed in a cylindrical shape with both ends closed. The case 11 houses the electric motor 14, the shaft 15, and the compression mechanism 20. Inside the case 11, in the -Z direction, is lubricating oil 12 for lubricating the compression mechanism 20. Inside the case 11, in the +Z direction, is gaseous refrigerant compressed by the compression mechanism 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.

[0025] 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.

[0026] The shaft 15 is arranged coaxially with the case 11. The rotor 14b of the motor unit 14 is fixed to the shaft 15 in the +Z direction. The rotor 16 of the compression mechanism unit 20 is fixed to the shaft 15 in the -Z direction. The motor unit 14 rotates the rotor 16 via the shaft 15. The shaft 15 and rotor 16 are separate components, but they may be integrated.

[0027] The compression mechanism 20 is located inside the case 11 in the -Z direction. The compression mechanism 20 includes a cylinder 21, a rotor 16, vanes 17 (see Figure 2), a first bearing 30, a second bearing 35, and a muffler 33.

[0028] The cylinder 21 is positioned coaxially with the case 11. The cylinder 21 is fixed to the inner circumferential surface of the case 11. As shown in Figure 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.

[0029] The rotor 16 is formed in a cylindrical shape. The rotor 16 is positioned inside the cylinder chamber 22. The space between the outer surface of the rotor 16 and the inner wall surface of the cylinder 21 functions as the actual cylinder chamber 22. The rotor 16 is positioned coaxially with the shaft 15. The axis of rotation 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.

[0030] The distance between the outer surface of the rotor 16 and the inner wall surface of the cylinder 21 in the R direction (hereinafter simply referred to as the distance between the rotor and cylinder 21) changes along the θ direction. The distance between the rotor and cylinder 26 is maximized in the direction of eccentricity of the central axis of the cylinder chamber 22 with respect to the central axis of the cylinder 21 (upward direction in Figure 2). The position where the distance between the rotor and cylinder 26 is maximized in the θ direction is called the bottom dead center B. On the other hand, the distance between the rotor and cylinder 26 is minimized in the opposite direction of eccentricity of the central axis of the cylinder chamber 22 (downward direction in Figure 2). The position where the distance between the rotor and cylinder 22 is minimized in the θ direction is called the top dead center (minimum distance position) T. In the example in Figure 2, there is only one top dead center T in the θ direction. In other words, when the rotor 16 rotates once from the top dead center T, the distance between the rotor and cylinder 22 simply increases as the rotor 16 passes the bottom dead center B, and then the distance between the rotor and cylinder 22 simply decreases as the rotor 16 returns to its original top dead center T. There may be multiple top dead centers T in the θ direction.

[0031] As shown in Figure 2, cylinder 21 has a refrigerant intake port 25 and a discharge port 41. The intake port 25 and the 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.

[0032] 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 T of the cylinder chamber 22. The discharge port 41 is located upstream of the top dead center T of the cylinder chamber 22.

[0033] The vanes 17 are formed in a flat plate shape from a metallic material. The vanes 17 are 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 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 end of the slit. 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 vanes 17. In addition, centrifugal force acts on the vanes 17 as the rotor 16 rotates. The vanes 17 are 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 vanes 17 move back and forth relative to the cylinder chamber 22 as the rotor 16 rotates.

[0034] 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 23 in the θ direction. As the rotor 16 rotates, the small chambers move in the +θ direction. When a small chamber moves from top dead center T to bottom dead center B, its volume increases. The small chamber, which communicates with the suction port 25, draws in gaseous refrigerant from the suction port 25 as its volume increases. When a small chamber moves from bottom dead center B to top dead center T, its volume decreases. The small chamber compresses the gaseous refrigerant as its volume decreases. High-pressure gaseous refrigerant is discharged from the discharge port 41.

[0035] 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.

[0036] 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 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.

[0037] As shown in Figure 1, the 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.

[0038] The 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.

[0039] The 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 interior of the case 11 through the opening between the bearing portion 31 of the first bearing 30 and the muffler 33.

[0040] The discharge unit 40, including the discharge port 41, will be described below. The rotary compressor 10 has multiple discharge units 40, as shown in Figure 2. In the example in Figure 2, there are two discharge units 40, but there may be three or more discharge units 40. The two discharge units 40 in the example in Figure 2 are the first discharge unit 40a and the second discharge unit 40b. The first discharge unit 40a is located on the downstream side, and the second discharge unit 40b is located on the upstream side.

[0041] The first discharge unit 40a includes a first muffler chamber 48a, a first discharge hole 41a, a first reed valve 42a, and a first regulating member 46a. The first muffler chamber 48a is formed in a recess on the outer circumference of the cylinder 21. The opening of the first muffler chamber 48a in the +R direction is closed by a cover member 49a. A first communication passage 34a is formed on the side surface of the first muffler chamber 48a in the +Z direction, communicating with the muffler chamber 34 (see Figure 1).

[0042] The first discharge hole 41a is formed on the inner wall surface of the cylinder 21. The first discharge hole 41a is formed in the center of the cylinder 21 in the Z direction. When viewed from the R direction, the first discharge hole 41a is, for example, circular in shape. The first discharge hole 41a penetrates the cylinder 21 in the R direction. The first discharge hole 41a connects the cylinder chamber 22 and the first muffler chamber 48a. The first muffler chamber 48a is formed outside the cylinder chamber 22, with the first discharge hole 41a in between. The first discharge hole 41a is positioned upstream of top dead center T.

[0043] Figure 6 is an enlarged view of the area around the first discharge hole 41a and the second discharge hole 41b. The cylinder 21 has an introduction groove 28 on its inner wall surface. The introduction groove 28 is formed in the center of the cylinder 21 in the Z direction. When viewed from the R direction, the introduction groove 28 is, for example, rectangular in shape. The depth of the introduction groove 28 increases from the upstream end to the center in the θ direction, and decreases from the center in the θ direction to the downstream end. The upstream end of the first discharge hole 41a is located in the center of the introduction groove 28 in the θ direction. That is, the introduction groove 28 extends upstream from the first discharge hole 41a.

[0044] 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 introduction groove 28 increases the flow path cross-sectional area of ​​the cylinder chamber 22 from the upstream side of the first discharge hole 41a to the first discharge hole 41a. The introduction groove 28 introduces the refrigerant into the first discharge hole 41a.

[0045] The first reed valve 42a is made of a metal plate as shown in Figure 2. The first reed valve 42a is located inside the first muffler chamber 48a. The first reed valve 42a has a first opening / closing section 43a, a first fixing section 45a, and a first intermediate section 44a. The first opening / closing section 43a opens and closes the first discharge hole 41a. Viewed from the R direction, the outer shape of the first opening / closing section 43a is larger than the first discharge hole 41a. The first fixing section 45a fixes the first reed valve 42a to the cylinder 21 with bolts or the like. The first intermediate section 44a is located between the first opening / closing section 43a and the first fixing section 45a in the θ direction and connects the two. The first intermediate section 44a is elastically deformable from a flat state to a curved state. When the first intermediate section 44a is curved, the first opening / closing section 43a moves in the +R direction, and the first discharge hole 41a transitions to an open state (referred to as the open state). When the first intermediate section 44a returns to its flat state, the first opening / closing section 43a moves in the -R direction, and the first discharge hole 41a transitions to a closed state (referred to as the closed state).

[0046] The first regulating member 46a is positioned in the +R direction of the first reed valve 42a. The first regulating member 46a restricts excessive movement of the first reed valve 42a in the +R direction.

[0047] The second discharge unit 40b is the same as the first discharge unit 40a. The second discharge unit 40b has a second muffler chamber 48b, a second discharge hole 41b, a second reed valve 42b, and a second regulating member 46b. The second reed valve 42b has a second opening / closing section 43b, a second fixing section 45b, and a second intermediate section 44b. The configuration around the first discharge port 41a and the second discharge port 41b, including the differences between the first discharge unit 40a and the second discharge unit 40b, will be described in detail later.

[0048] The operation of the compression mechanism 20 will now be described. Figure 3-5 is an explanatory diagram of the first to third operations of the compression mechanism 20, and is a part of the cross-sectional view along line II-II in Figure 1. In Figure 3, the vane 17 on the downstream side is called the first vane 17a, and the vane 17 on the upstream side is called the second vane 17b. The cylinder chamber 22 is divided by the first vane 17a and the second vane 17b, and the first small chamber 23a is formed between the first vane 17a and the second vane 17b. In the state shown in Figure 3, the first vane 17a is located downstream of the first discharge hole 41a, and the second vane 17b is located upstream of the second discharge hole 41b. That is, the first small chamber 23a is in communication with both the first discharge hole 41a and the second discharge hole 41b.

[0049] The minimum pressure in the first chamber 23a when the first reed valve 42a opens the first discharge port 41a is defined as the first discharge pressure. The minimum pressure in the first chamber 23a when the second reed valve 42b opens the second discharge port 41b is defined as the second discharge pressure. The lowest of the first and second discharge pressures is defined as the minimum discharge pressure. The highest of the first and second discharge pressures is defined as the common discharge pressure. In the state shown in Figure 3, the refrigerant pressure in the first chamber 23a has reached the minimum discharge pressure. The first discharge port 41a and / or the second discharge port 41b transition from the closed state to the open state. The refrigerant in the first chamber 23a is discharged from the first discharge port 41a and / or the second discharge port 41b.

[0050] From Figure 3 to Figure 4, the first vane 17a and the second vane 17b rotate in the +θ direction along with the rotor 16. The position of the second vane 17b in Figure 3 is shown by a dashed line in Figure 4. The pressure in the first chamber 23a exceeds the common discharge pressure. Both the first discharge port 41a and the second discharge port 41b transition from the closed state to the open state. The refrigerant in the first chamber 23a is discharged from both the first discharge port 41a and the second discharge port 41b.

[0051] In the state shown in Figure 4, the second vane 17b passes through the second discharge port 41b. The first chamber 23a communicates only with the first discharge port 41a. The pressure in the first chamber 23a is greater than or equal to the first discharge pressure, and the first discharge port 41a is kept open. The refrigerant in the first chamber 23a is discharged from the first discharge port 41a. On the other hand, the second chamber 23b upstream of the second vane 17b communicates only with the second discharge port 41b. The pressure in the second chamber 23b is less than the second discharge pressure. The second discharge port 41b transitions from the open state to the closed state.

[0052] From Figure 4 to Figure 5, the first vane 17a and the second vane 17b rotate in the +θ direction along with the rotor 16. The position of the second vane 17b in Figure 4 is shown by a dashed line in Figure 5. Almost all of the refrigerant in the first chamber 23a is discharged from the first discharge port 41a.

[0053] In the state shown in Figure 5, the second vane 17b passes through the first discharge port 41a. The second chamber 23b communicates with both the first discharge port 41a and the second discharge port 41b. The pressure in the second chamber 23b is still below the minimum discharge pressure. The first discharge port 41a transitions from the open state to the closed state. The second discharge port 41b remains in the closed state.

[0054] When the rotor 16 rotates in the +θ direction from the state shown in Figure 5, it reaches the state shown in Figure 3. The second vane 17b in Figure 5 corresponds to the first vane 17a in Figure 3. The compression mechanism 20 repeats the state shown in Figure 3-5 as described above. As a result, the compression mechanism 20 repeatedly draws in, compresses, and discharges the refrigerant.

[0055] The configuration around the first discharge port 41a and the second discharge port 41b will be described in detail. As described above with reference to Figure 2, 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 flow path cross-sectional area of ​​the cylinder chamber 22 decreases from bottom dead center B to top dead center T. The first discharge port 41a is located near top dead center T. During the process of refrigerant flowing from the cylinder chamber 22 to the first discharge port 41a, pressure loss (sometimes called flow path loss) occurs due to flow resistance.

[0056] The rotary compressor 10 of this embodiment has a first discharge port 41a and a second discharge port 41b. The second discharge port 41b is located upstream of the first discharge port 41a. By arranging the discharge ports 41a and 41b in a dispersed manner in the θ direction, flow path losses are suppressed during the process of refrigerant flowing from the cylinder chamber 22 into the discharge ports 41a and 41b. This suppresses a decrease in the compression efficiency of the rotary compressor 10.

[0057] As mentioned above, in Figure 4, the second vane 17b passes through the second discharge port 41b, and in Figure 5, the second vane 17b passes through the first discharge port 41a. At this time, the pressure in the first chamber 23a is high, above the common discharge pressure, and the pressure in the second chamber 23b is low, below the minimum discharge pressure (intermediate pressure). The pressure inside the discharge ports 41a and 41b through which the second vane 17b passes shifts from the high pressure in the first chamber 23a to the low pressure in the second chamber 23b. As a result, a differential pressure that causes the discharge ports 41a and 41b to close acts abruptly on the reed valves 42a and 42b. The pressure in the second chamber 23b when the second vane 17b passes through the second discharge port 41b is lower than the pressure in the second chamber 23b when the second vane 17b passes through the first discharge port 41a. The differential pressure required to close the second discharge port 41b is greater than the differential pressure required to close the first discharge port 41a. Therefore, when the second discharge port 41b closes, the impact force between the second opening / closing section 43b of the second reed valve 42b and the valve seat increases. Furthermore, after closing, the deformation of the second opening / closing section 43b increases. These factors may cause damage to the second reed valve 42b.

[0058] As mentioned above, the first reed valve 42a and the second reed valve 42b are made of metal plates. In this embodiment, the plate thickness of the second reed valve 42b is greater than that of the first reed valve 42a. This increases the rigidity of the second reed valve 42b and suppresses damage to the second vane 17b. On the other hand, the rigidity of the first reed valve 42a is reduced. This lowers the first discharge pressure and suppresses overcompression of the refrigerant. In addition, the first reed valve 42a is made lighter and its responsiveness is improved. This suppresses backflow of refrigerant from the first muffler chamber 48a to the first discharge port 41a.

[0059] As shown in Figure 2, the flow path cross-sectional area of ​​the cylinder chamber 22 at the upstream end of the second discharge hole 41b is larger than the flow path cross-sectional area of ​​the cylinder chamber 22 at the upstream end of the first discharge hole 41a. In this embodiment, the flow path cross-sectional area of ​​the second discharge port 41b is larger than the flow path cross-sectional area of ​​the first discharge port 41a. This reduces the difference in flow path cross-sectional area before and after the inflow of refrigerant into the second discharge port 41b and the first discharge port 41a, thereby suppressing flow path loss. In proportion to the increase in the flow path cross-sectional area of ​​the second discharge port 41b, the pressure-receiving area of ​​the second opening / closing portion 43b of the second reed valve 42b increases. As mentioned above, the plate thickness of the second reed valve 42b is greater than the plate thickness of the first reed valve 42a. This suppresses damage to the second reed valve 42b.

[0060] As mentioned above, in Figure 4, the second vane 17b passes through the second discharge port 41b, and in Figure 5, the second vane 17b passes through the first discharge port 41a. At this time, the pressure inside the discharge ports 41a and 41b shifts from the high pressure in the first chamber 23a to the low pressure (intermediate pressure) in the second chamber 23b. As a result, the discharge ports 41a and 41b shift from the open state to the closed state. If the reed valves 42a and 42b have low responsiveness, it takes time to shift from the open state to the closed state. Therefore, refrigerant flows back from the high-pressure muffler chambers 48a and 48b to the low-pressure discharge ports 41a and 41b. As mentioned above, the pressure in the second chamber 23b when the second vane 17b passes through the second discharge port 41b is lower than the pressure in the second chamber 23b when the second vane 17b passes through the first discharge port 41a. Therefore, there is a high possibility that refrigerant will flow back from the second muffler chamber 48b to the second discharge port 41b.

[0061] The responsiveness of the reed valves 42a and 42b is proportional to the natural frequency f of the reed valves 42a and 42b, which is expressed by Equation 1.

[0062]

number

[0063] In this embodiment, the natural frequency f of the second reed valve 42b is greater than the natural frequency f of the first reed valve 42a. Because the second reed valve 42b is highly responsive, the second discharge port 41b closes in a short time. This suppresses the backflow of refrigerant from the second muffler chamber 48b to the second discharge port 41b. On the other hand, because the first reed valve 42a is less responsive, the time it takes for the first discharge port 41a to close is longer. As a result, most of the refrigerant in the first small chamber 23a is discharged from the first discharge port 41a, and less refrigerant remains in the first small chamber 23a. Therefore, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0064] As described above, the minimum pressure in the first chamber 23a where the first reed valve 42a opens the first discharge port 41a is defined as the first discharge pressure. The minimum pressure in the first chamber 23a where the second reed valve 42b opens the second discharge port 41b is defined as the second discharge pressure. In this embodiment, the first discharge pressure is lower than the second discharge pressure.

[0065] In this embodiment, the spring constant of the first intermediate section 44a of the first reed valve 42a is smaller than the spring constant of the second intermediate section 44b of the second reed valve 42b. As a result, the opening timing of the first reed valve 42a and the second reed valve 42b is different. This suppresses refrigerant discharge pulsation and also suppresses resonance of discharge pulsation. Therefore, the noise of the rotary compressor is suppressed. According to Equation 1, the larger the spring constant K of the intermediate sections 44a and 44b, the larger the natural frequency f. Since the spring constant of the second intermediate section 44b is larger than that of the first intermediate section 44a, the natural frequency f of the second reed valve 42b is larger than that of the first reed valve 42a. As a result, as described above, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0066] As shown in Figure 2, the second fixed portion 45b of the second reed valve 42b is positioned upstream of the second discharge port 41b. In contrast, the first fixed portion 45a of the first reed valve 42a is positioned downstream of the first discharge port 41a. In addition, the first discharge port 41a is positioned upstream of top dead center T, and the first fixed portion 45a is positioned downstream of top dead center T. That is, the first discharge port 41a and the first fixed portion 45a are positioned on either side of top dead center T in the θ direction.

[0067] As a result, as shown in Figure 3, the first discharge port 41a and the second discharge port 41b approach each other in the θ direction. After the first small chamber 23a exceeds the minimum discharge pressure, the time during which the first small chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b increases. This allows the refrigerant from the first small chamber 23a to be discharged smoothly, thereby suppressing flow loss.

[0068] Furthermore, the first discharge port 41a is positioned at the downstream end, close to the top dead center T. As a result, most of the refrigerant in the first chamber 23a is discharged through the first discharge port 41a, reducing the amount of refrigerant remaining in the first chamber 23a. Therefore, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0069] As mentioned above, the pressure in the second chamber 23b when the second vane 17b passes through the second discharge port 41b (see Figure 4) is lower than the pressure in the second chamber 23b when the second vane 17b passes through the first discharge port 41a (see Figure 5). In other words, the further upstream the second discharge port 41b is, the lower the pressure in the second chamber 23b when the second vane 17b passes through the second discharge port 41b. In this embodiment, the second discharge port 41b is positioned downstream of the first discharge port 41a, closer to it. This increases the pressure in the second chamber 23b when the second vane 17b passes through the second discharge port 41b. Therefore, backflow of refrigerant from the second muffler chamber 48b to the second discharge port 41b is suppressed. In addition, the differential pressure required to close the second discharge port 41b is reduced, and damage to the second reed valve 42b is suppressed.

[0070] As mentioned above, in the state shown in Figure 3, the first chamber 23a has reached the minimum discharge pressure. From the state shown in Figure 3, the refrigerant discharge process of the first chamber 23a begins. The first chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b. In the state shown in Figure 4, the second vane 17b passes through the second discharge port 41b. The first chamber 23a communicates only with the first discharge port 41a. That is, the first rotation angle range of the rotor 16 in which the first chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b is the range shown by θ1 in Figure 4.

[0071] In the state shown in Figure 5, the second vane 17b passes through the first discharge port 41a, and communication between the first chamber 23a and the first discharge port 41a ends. That is, the second rotation angle range of the rotor 16 in which the first chamber 23a communicates only with the first discharge port 41a is the range shown by θ2 in Figure 5. In the state shown in Figure 5, the refrigerant discharge process from the first chamber 23a is completed.

[0072] In this embodiment, θ1 > θ2 holds true. As a result, the opening area of ​​the discharge hole 41 becomes larger in the first half of the discharge process. The discharge flow rate of the refrigerant from the first small chamber 23a increases in the first half of the discharge process. As a result, the refrigerant from the first small chamber 23a is discharged smoothly, and flow path losses are suppressed.

[0073] Figure 6 is an enlarged view of the area around the first discharge port 41a and the second discharge port 41b, and is part of the cross-sectional view along line II-II in Figure 1. Let A1 be the flow path cross-sectional area of ​​the cylinder chamber 22 at the upstream end of the second discharge hole 41b. Let A2 be the flow path cross-sectional area of ​​the second discharge hole 41b. If multiple second discharge holes 41b are aligned in the Z direction, A2 shall be the sum of the flow path cross-sectional areas of the multiple second discharge holes 41b. Let A3 be the flow path cross-sectional area of ​​the cylinder chamber 22 at the upstream end of the first discharge hole 41a. A3 also includes the cross-sectional area of ​​the introduction groove 28. In this embodiment, A1 > A2 > A3 holds true.

[0074] Since A1 > A2 holds true, the refrigerant flows smoothly into the second discharge port 41b. Because the area of ​​A2 is limited, backflow of refrigerant from the second muffler chamber 48b to the second discharge port 41b is suppressed. Since A2 > A3 holds true, flow path losses are suppressed in the first half of the discharge process when the refrigerant discharge flow rate is high. Because A3 is small, the first discharge port 41a is more likely to be positioned downstream.

[0075] As shown in Figure 2, the cylinder 21 has a first muffler chamber 48a and a second muffler chamber 48b. The first muffler chamber 48a is formed outside the cylinder chamber 22, straddling the first discharge hole 41a. The second muffler chamber 48b is formed outside the cylinder chamber 22, straddling the second discharge hole 41b. In this embodiment, the volume of the second muffler chamber 48b is larger than the volume of the first muffler chamber 48a.

[0076] As mentioned above, since A1 > A3 holds true, the amount of refrigerant discharged from the second discharge port 41b is greater than that from the first discharge port 41a. Since the volume of the second muffler chamber 48b is larger than that of the first muffler chamber 48a, flow path losses are suppressed. The refrigerant in the cylinder chamber 22 is discharged in a distributed manner from the second discharge port 41b to the second muffler chamber 48b and from the first discharge port 41a to the first muffler chamber 48a. This reduces discharge pulsation.

[0077] 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.

[0078] According to at least one embodiment described above, the system has a first reed valve 42a that opens and closes the first discharge port 41a on the downstream side and a second reed valve 42b that opens and closes the second discharge port 41b on the upstream side. This makes it possible to suppress a decrease in the compression performance of the refrigerant.

[0079] 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]

[0080] T...Top dead center (minimum distance position), θ1...First rotation angle range, θ2...Second rotation angle range, 1...Refrigeration cycle device, 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, 41a...First discharge port, 41b...Second discharge port, 42a...First reed valve, 42b...Second reed valve, 45a...First fixed part, 45b...Second fixed part, 48a...First muffler chamber, 48b...Second muffler chamber.

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 positioned in the slits, which move forward and backward relative to the cylinder chamber as the rotor rotates, dividing the cylinder chamber into smaller chambers. The cylinder has a first discharge port and a second discharge port for discharging the fluid compressed in the small chamber to the outside of the cylinder chamber. The second discharge port is positioned upstream of the first discharge port in the rotational direction of the rotor, The system further comprises a first reed valve that opens and closes the first discharge hole and a second reed valve that opens and closes the second discharge hole, located outside the cylinder chamber. Rotary compressor.

2. The plate thickness of the second reed valve is greater than the plate thickness of the first reed valve. The rotary compressor according to claim 1.

3. The cross-sectional area of ​​the flow path of the second discharge hole is larger than the cross-sectional area of ​​the flow path of the first discharge hole. The rotary compressor according to claim 2.

4. The natural frequency of the second reed valve is greater than the natural frequency of the first reed valve. The rotary compressor according to claim 2 or 3.

5. The spring constant of the first reed valve is smaller than the spring constant of the second reed valve. The rotary compressor according to claim 2 or 3.

6. The first fixing portion for fixing the first reed valve to the cylinder is positioned downstream of the first discharge hole in the rotational direction of the rotor, The second fixing portion for fixing the second reed valve to the cylinder is positioned on the upstream side with respect to the second discharge hole. When the position in the rotational direction of the rotor where the distance between the outer circumferential surface of the rotor and the inner wall surface of the cylinder is minimized is defined as the minimum separation position, The first discharge hole is located upstream of the minimum separation position, and the first fixing part is located downstream of the minimum separation position. The rotary compressor according to claim 1.

7. When the minimum pressure in the small chamber at which the first reed valve opens the first discharge port is defined as the first discharge pressure, and the minimum pressure in the small chamber at which the second reed valve opens the second discharge port is defined as the second discharge pressure, and the smaller of the first discharge pressure and the second discharge pressure is defined as the minimum discharge pressure, After the chamber reaches the minimum discharge pressure, the first rotational angle range of the rotor in which the chamber communicates with both the first and second discharge holes is greater than the second rotational angle range of the rotor in which the chamber communicates with only the first discharge hole. The rotary compressor according to claim 6.

8. The cross-section of the cylinder chamber between the outer circumferential surface of the rotor and the inner wall surface of the cylinder, with respect to the plane including the rotation axis, is defined as the flow path cross-section of the cylinder chamber. When the flow path cross-sectional area of ​​the cylinder chamber at the upstream end of the second discharge hole is A1, the flow path cross-sectional area of ​​the second discharge hole is A2, and the flow path cross-sectional area of ​​the cylinder chamber at the upstream end of the first discharge hole is A3, then A1 > A2 > A3 holds true. The rotary compressor according to claim 6 or 7.

9. The cylinder has a first muffler chamber formed outside the cylinder chamber, straddling the first discharge hole, and a second muffler chamber formed outside the cylinder chamber, straddling the second discharge hole. The volume of the second muffler chamber is greater than the volume of the first muffler chamber. The rotary compressor according to claim 6 or 7.

10. A rotary compressor according to claim 2 or 6, 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.

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