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 includes a cylinder, a rotor, and vanes. The rotor rotates around a rotation axis eccentric with respect to the cylinder chamber. The vanes are arranged in slits in the rotor and divide the cylinder chamber into smaller chambers. The cylinder has a first discharge port and a second discharge port. The second discharge port is located upstream of the first discharge port in the direction of rotation of the rotor. The first discharge port is open to the outside of the cylinder chamber. The second discharge port is opened and closed by a valve body located outside the cylinder chamber. The first rotation angle range of the rotor in which the smaller chamber communicates with both the first and second discharge ports is defined as φ1. The second rotation angle range of the rotor in which the smaller chamber communicates with only the second discharge port is defined as φ2. In this case, φ1 > φ2 holds true.

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 rotation axis 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. <00000​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​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 first discharge port is open to the outside of the cylinder chamber. The second discharge port is opened and closed by a valve located outside the cylinder chamber. The first rotation angle range of the rotor in which the smaller chambers communicate with both the first and second discharge ports is denoted as φ1. The second rotation angle range of the rotor in which the smaller chambers communicate with only the second discharge port is denoted as φ2. In this case, φ1 > φ2 holds true.

[0007] The rotary compressor of Embodiment 2 is based on the rotary compressor described in Embodiment 1. The cylinder has an inlet groove on its inner wall surface. The inlet groove extends upstream from the first discharge hole.

[0008] The rotary compressor of Embodiment 3 is based on the rotary compressor described in Embodiment 2. 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 inlet groove. Let A2 be the flow path cross-sectional area of ​​the second discharge hole. In this case, A1 > A2 holds true.

[0009] The rotary compressor of Embodiment 4 is based on the rotary compressor described in Embodiment 2 or 3. The minimum separation position where the distance between the outer surface of the rotor and the inner wall surface of the cylinder is minimized is only one in the direction of rotor rotation. Let α (rad) be the angular range between the upstream end of the second discharge hole and the upstream end of the introduction groove with respect to the rotation axis. Let n be the number of vanes arranged at equal angular intervals. In this case, α < π / n holds true.

[0010] The rotary compressor of Embodiment 5 is based on the rotary compressor described in Embodiment 4. The valve body is a reed valve. Let f be the natural frequency of the reed valve and N be the rotational speed of the rotor. In this case, Equation 1 holds true.

[0011]

number

[0012] 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 5. 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]

[0013] [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] First operational diagram of the compression mechanism. [Figure 4] Second operational diagram of the compression mechanism. [Figure 5] Third operational diagram of the compression mechanism. [Figure 6] Enlarged view of the area around the first and second discharge holes. [Modes for carrying out the invention]

[0014] 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.

[0015] 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) 2b is arranged on the upstream side of the rotary compressor 10. The accumulator 2b separates the gas-liquid two-phase refrigerant and supplies the gaseous refrigerant to the rotary compressor 10.

[0016] The four-way valve 3 reverses the flow direction of the refrigerant in the refrigerant flow path 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 this 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 this 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).

[0017] The condenser dissipates heat from the high-temperature and high-pressure gaseous refrigerant discharged from the rotary compressor 10 and converts 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 sent from the condenser and converts 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 sent 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-mentioned rotary compressor 10 via the accumulator 2b.

[0018] In this way, 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.

[0019] FIG. 1 includes a cross-sectional view of the rotary compressor 10 in an embodiment. FIG. 2 is a cross-sectional view of the compression mechanism portion 20 taken along 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 vertically upward. The R direction is the radial direction of the rotor 16. The +R direction is the direction outward in the radial direction. The θ direction is the circumferential direction of the rotor 16. The +θ direction (downstream side) is the rotational direction of a right-handed screw that advances in the -Z direction. The directions opposite to the +Z direction, +R direction, and +θ direction are the -Z direction, -R direction, and -θ direction (upstream side), respectively.

[0020] 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.

[0021] The case 11 is formed in a cylindrical shape with both ends closed. The case 11 houses the motor portion 14, the shaft 15, and the compression mechanism portion 20. Lubricating oil 12 for lubricating the compression mechanism portion 20 is housed in the -Z direction inside the case 11. Gas refrigerant compressed by the compression mechanism portion 20 is housed in the +Z direction inside the case 11. The gas refrigerant and lubricating oil inside the case 11 are at high pressure. The gas refrigerant is supplied from the discharge port 13 in the +Z direction of the case 11 to the four-way valve 3 through the refrigerant flow path 8.

[0022] The motor portion 14 is disposed in the +Z direction inside the case 11. The motor portion 14 includes a stator 14a and a rotor 14b. The stator 14a is fixed to the inner peripheral surface of the case 11. The rotor 14b is disposed in the -R direction of the stator 14a.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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 5 vanes 17, but there may be 4 or fewer vanes 17, or 6 or more vanes 17.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] Let me explain the discharge port 41. The rotary compressor 10 has a plurality of discharge holes 41, as shown in Figure 2. The discharge holes 41 are formed on the inner wall surface of the cylinder 21. The discharge holes 41 are formed in the center of the cylinder 21 in the Z direction. When viewed from the R direction, the discharge holes 41 are, for example, circular in shape. In the example of Figure 2, there are two discharge holes 41, but there may be three or more discharge holes 41. The two discharge holes 41 in the example of Figure 2 are the first discharge hole 41a and the second discharge hole 41b. The first discharge hole 41a is located on the downstream side, and the second discharge hole 41b is located on the upstream side.

[0038] The first discharge port 41a is located upstream of the top dead center T. The first discharge port 41a extends in the +R direction from the inner wall surface of the cylinder 21 and communicates with the first communication passage 34a. The first communication passage 34a extends in the +Z direction inside the cylinder 21 and communicates with the muffler chamber 34 (see Figure 1). The first discharge port 41a is open to the first communication passage 34a and the muffler chamber 34, which are outside the cylinder chamber 22.

[0039] 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.

[0040] 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 O 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 inlet of the first discharge hole 41a. The introduction groove 28 introduces the refrigerant from the cylinder chamber 22 into the first discharge hole 41a.

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

[0042] The second discharge port 41b penetrates the cylinder 21 in the R direction. The second discharge port 41b connects the cylinder chamber 22 and the intermediate muffler chamber 48. The intermediate muffler chamber 48 is formed outside the cylinder chamber 22, with the second discharge port 41b in between.

[0043] As shown in Figure 2, the valve body 42 is positioned inside the intermediate muffler chamber 48. The valve body 42 is a reed valve formed, for example, from a metal plate. The valve body 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 second discharge hole 41b. Viewed from the R direction, the outer shape of the opening / closing section 43 is larger than the second discharge hole 41b. The fixed section 45 fixes the valve body 42 to the cylinder 21 with bolts or the like. The intermediate section 44 is positioned 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 second discharge hole 41b moves to an open state (referred to as the open state). When the intermediate section 44 returns to its flat position, the opening / closing section 43 moves in the -R direction, and the second discharge hole 41b transitions to a closed state (referred to as the closed state). The valve body 42 may also have a structure in which the opening / closing section 43 is opened and closed by a coil spring, instead of a reed valve.

[0044] The regulating member 46 is positioned in the +R direction of the valve body 42. The regulating member 46 restricts excessive movement of the valve body 42 in the +R direction. The configuration around the first discharge port 41a and the second discharge port 41b will be described in detail later.

[0045] 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.

[0046] 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. Figure 3 shows the state when the first vane 17a has reached the second discharge port 41b. The first small chamber 23a begins to communicate with the second discharge port 41b. The minimum discharge pressure is defined as the minimum pressure in the first small chamber 23a at which the valve body 42 opens the second discharge port 41b. In the state shown in Figure 3, the refrigerant pressure in the first small chamber 23a is less than the minimum discharge pressure. The second discharge port 41b is closed.

[0047] 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 minimum discharge pressure. The second discharge port 41b transitions from a closed state to an open state. The refrigerant in the first chamber 23a is discharged from the second discharge port 41b.

[0048] Figure 4 shows the state when the first vane 17a has reached the introduction groove 28. The first chamber 23a begins to communicate with the first discharge port 41a. The first chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b. As mentioned above, the first discharge port 41a is open, but the second discharge port 41b is opened and closed by the valve body 42. The discharge resistance of the first discharge port 41a is smaller than that of the second discharge port 41b. The refrigerant in the first chamber 23a is preferentially discharged from the first discharge port 41a.

[0049] 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. The refrigerant from the first chamber 23a is discharged from the first discharge port 41a and the second discharge port 41b.

[0050] Figure 5 shows the state after the second vane 17b has passed through the second discharge port 41b. The first chamber 23a has finished communicating with the second discharge port 41b and is now communicating only with the first discharge port 41b. Subsequently, the second vane 17b rotates in the +θ direction together with the rotor 16. Almost all of the refrigerant in the first chamber 23a is discharged from the first discharge port 41a. On the other hand, when the second discharge port 41b communicates with the second chamber 23b, which has not yet reached the minimum discharge pressure, the valve body 42 causes the second discharge port 41b to transition from the open state to the closed state.

[0051] Figures 3 and 5 show nearly identical states. 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.

[0052] The configuration around the first discharge port 41a and the second discharge port 41b will be described in detail. As described above, the first chamber 23a begins communicating with the second discharge port 41b from the state shown in Figure 3. The first chamber 23a begins communicating with both the first discharge port 41a and the second discharge port 41b from the state shown in Figure 4. That is, the second rotation angle range of the rotor 16 in which the first chamber 23a communicates only with the second discharge port 41b is the range shown by φ2 in Figure 4. Furthermore, the first chamber 23a ends its communication with the second discharge port 41b in the state shown in Figure 5. 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 φ1 in Figure 5. In this embodiment, φ1 > φ2 holds true. Therefore, the time during which the first chamber 23a is in communication with both the first discharge port 41a and the second discharge port 41b is longer than the time during which the first chamber 23a is in communication with only the second discharge port 41b.

[0053] As mentioned above, in Figure 5, the second vane 17b passes through the second discharge port 41b. At this time, the pressure in the second chamber 23b upstream of the second vane 17b is lower than the pressure in the first chamber 23a downstream of the second vane 17b. The pressure inside the second discharge port 41b through which the second vane 17b passes transitions from the high pressure of the first chamber 23a to the low pressure (intermediate pressure) of the second chamber 23b. At this time, if the second discharge port 41b is open, the high-pressure refrigerant discharged into the intermediate muffler chamber 48 flows back into the second discharge port 41b. This reduces the compression efficiency of the rotary compressor 10.

[0054] In this embodiment, φ1 > φ2 holds true. That is, the first rotation angle range φ1, in which the first chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b, is greater than the second rotation angle range φ2, in which it communicates only with the second discharge port 41b. In the first rotation angle range φ1, the refrigerant in the first chamber 23a is preferentially discharged from the first discharge port 41a. When the second discharge port 41b communicates with the second chamber 23b, which has not reached the minimum discharge pressure, the valve body 42 causes the second discharge port 41b to transition to a closed state. Because the first rotation angle range φ1 is large, the opening of the valve body 42 becomes small by the end of the first rotation angle range φ1, making it easier for the second discharge port 41b to transition to a closed state. As a result, in the state shown in Figure 5, at the end of the first rotation angle range φ1, backflow of refrigerant from the intermediate muffler chamber 48 to the second discharge port 41b is suppressed. Therefore, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0055] As shown in Figure 6, the cylinder 21 has an introduction groove 28. This increases the flow path cross-sectional area of ​​the cylinder chamber 22 from the upstream side of the first discharge hole 41a to the inlet of the first discharge hole 41a. Therefore, when refrigerant flows from the cylinder chamber 22 to the first discharge hole 41a, the pressure loss due to flow resistance (sometimes called flow path loss) is small. The refrigerant in the first small chamber 23a is easily discharged from the first discharge hole 41a. The second discharge hole 41b is easily closed by the end of the first rotation angle range φ1. In the state shown in Figure 5, backflow of refrigerant from the intermediate muffler chamber 48 to the second discharge hole 41b is suppressed.

[0056] Let A1 be the flow path cross-sectional area of ​​the cylinder chamber 22 at the upstream end of the introduction groove 28. On the other hand, let A2 be the flow path cross-sectional area of ​​the second discharge hole 41b. In this embodiment, A1 > A2 holds true. Since the flow path cross-sectional area A1 of the cylinder chamber 22 at the upstream end of the introduction groove 28 is large, the flow path loss is small when the refrigerant flows from the cylinder chamber 22 to the first discharge hole 41a. The second discharge hole 41b is more likely to transition to a closed state by the end of the first rotation angle range φ1 shown in Figure 5.

[0057] As mentioned above, in Figure 5, the second vane 17b passes through the second discharge port 41b. The pressure inside the second discharge port 41b transitions from the high pressure in the first chamber 23a to the low pressure in the second chamber 23b. Even when the second discharge port 41b is closed, the high-pressure refrigerant remaining inside the second discharge port 41b flows out into the second chamber 23b. This reduces the compression efficiency of the rotary compressor 10.

[0058] In this embodiment, since A1 > A2 holds true, the flow path cross-sectional area A2 of the second discharge port 41b is small. The amount of high-pressure refrigerant remaining inside the second discharge port 41b and flowing out into the second small chamber 23b is small. Therefore, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0059] As mentioned above with reference to Figure 2, there is only one top dead center (minimum separation position) T in the θ direction. On the other hand, let α (rad) be the angular range between the upstream end of the second discharge hole 41b and the upstream end of the introduction groove 28 with respect to the rotation axis O of the rotor 16. Also, let n be the number of vanes 17 arranged at equal angular intervals. In this embodiment, α < π / n holds true.

[0060] In the state shown in Figure 3, the first vane 17a is at the upstream end of the second discharge hole 41b. In the state shown in Figure 4, the first vane 17a is at the upstream end of the introduction groove 28. From Figure 3 to Figure 4, the first vane 17a moves by a second rotational angle range φ2. The second rotational angle range φ2 is equal to the angle range α.

[0061] From Figure 4 to Figure 5, the second vane 17b moves by the first rotational angle range φ1. The position of the second vane 17b in Figure 5 is approximately equal to the position of the first vane 17a in Figure 3. The angular range between the first vane 17a and the second vane 17b is 2π / n. Based on Figure 3-5, φ1 + φ2 = 2π / n holds true. If φ1 = φ2, then 2 × φ2 = 2π / n. Furthermore, φ2 = π / n also holds true.

[0062] As mentioned above, in this embodiment, φ1 > φ2 holds true. That is, the first rotational angle range φ1, in which the first small chamber 23a communicates with both the first discharge hole 41a and the second discharge hole 41b, is greater than the second rotational angle range φ2, in which it communicates only with the second discharge hole 41b. Therefore, φ2 < π / n. As mentioned above, the second rotational angle range φ2 is equal to the angle range α. Thus, α < π / n holds true.

[0063] In other words, when α < π / n holds, then φ1 > φ2 holds. As a result, as mentioned above, backflow of refrigerant from the intermediate muffler chamber 48 to the second discharge port 41b is suppressed. Therefore, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0064] As mentioned above, the first rotational angle range in which the first small chamber 23a communicates with both the first discharge port 41a and the second discharge port 41b is φ1. Also, φ1 + φ2 = 2π / n, and φ2 = α. Therefore, φ1 = 2π / n - α holds true. Let T1 be the first time during which the first chamber 23a is in communication with both the first discharge port 41a and the second discharge port 41b. When the rotational speed of the rotor 16 is N, the angular velocity of the rotor 16 is expressed as 2πN (rad / s). Since T1 = φ1 / 2πN, the following equation 2 holds.

[0065]

number

[0066] As mentioned above, the valve body 42 is a reed valve. Let T2 be the second time it takes for the reed valve to go from fully open to fully closed. When the natural frequency of the reed valve is f, since the reed valve has a unidirectional structure, f = 1 / (4 × T2). Furthermore, T2 = 1 / (4 × f) holds true.

[0067] As shown in Figure 5, it is desirable that the second discharge port 41b is closed when the second vane 17b passes through it. To achieve this, the reed valve must go from fully open to fully closed while the first chamber 23a is communicating with both the first discharge port 41a and the second discharge port 41b, as shown from Figure 4 to Figure 5. That is, T1 > T2 must be obtained. Based on the T1 and T2 derived earlier, the following equation 3 holds true.

[0068]

number

[0069] The natural frequency f of a reed valve is expressed by the following equation 4.

[0070]

number

[0071] It is desirable to design the reed valve so as to satisfy equations 3 and 4. This causes the reed valve to move from fully open to fully closed while the first chamber 23a is communicating with both the first discharge port 41a and the second discharge port 41b, as shown from Figure 4 to Figure 5. As shown in Figure 5, the second discharge port 41b is closed when the second vane 17b passes through it. Therefore, backflow of refrigerant from the intermediate muffler chamber 48 to the second discharge port 41b is suppressed. Consequently, the decrease in the compression efficiency of the rotary compressor 10 is suppressed.

[0072] 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.

[0073] According to at least one embodiment described above, the compression mechanism 20 has such that φ1 > φ2 when the first rotation angle range in which the first chamber 23a communicates with both the first discharge hole 41a and the second discharge hole 41b is defined as φ1, and the second rotation angle range in which the first chamber 23a communicates only with the second discharge hole 41b is defined as φ2. This makes it possible to suppress a decrease in the compression efficiency of the rotary compressor 10.

[0074] 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]

[0075] T...Top dead center (minimum distance position), 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...Inlet groove, 41a...First discharge port, 41b...Second discharge port, 42...Valve body.

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 first discharge port is open to the outside of the cylinder chamber, The second discharge port is opened and closed by a valve body located outside the cylinder chamber. When the first rotational angle range of the rotor in which the small chamber communicates with both the first and second discharge holes is defined as φ1, and the second rotational angle range of the rotor in which the small chamber communicates only with the second discharge hole is defined as φ2, then φ1 > φ2 holds true. Rotary compressor.

2. The cylinder has an introduction groove on its inner wall surface, The introduction groove extends from the first discharge hole toward the upstream side, The rotary compressor according to claim 1.

3. 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 introduction groove is A1, and the flow path cross-sectional area of ​​the second discharge hole is A2, then A1 > A2 holds true. The rotary compressor according to claim 2.

4. The minimum separation position, where the distance between the outer circumferential surface of the rotor and the inner wall surface of the cylinder is minimized, is only one location in the rotational direction of the rotor. Let α (rad) be the angular range between the upstream end of the second discharge hole and the upstream end of the introduction groove with respect to the rotation axis, and let n be the number of vanes arranged at equal angular intervals, such that α < π / n holds. The rotary compressor according to claim 2 or 3.

5. The valve body is a reed valve, When the natural frequency of the reed valve is f and the rotational speed of the rotor is N, then equation 1 holds true. [Math 1] The rotary compressor according to claim 4.

6. 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.

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