JP2019132254A - Rotary compressor and refrigeration cycle device - Google Patents

Abstract

To provide a rotary compressor which suppresses the lowering of efficiency caused by an invalid capacity of a second discharge port, and can make a refrigerant merely circulate while rarely boosting the pressure of the refrigerant, and a refrigeration cycle device.SOLUTION: A rotary compressor comprises: a cylinder 21; a pair of block plates for blocking the cylinder 21; a roller 28 having an eccentric part 22 arranged in a cylinder chamber, and eccentrically rotating in the cylinder chamber; and a vane part for partitioning the cylinder chamber into a suction chamber 51 and a compression chamber 52 together with the roller 28. The block plates have at least two discharge ports 37, and a second discharge port 56 is arranged in a position in which connection with the cylinder chamber is disconnected by the roller 28 at a rotating-shaft rotation angle not smaller than 180° and not larger than 210°when defining a rotation angle θ to a rotation direction of a rotating shaft with a position of the vane part set at a θ0°.SELECTED DRAWING: Figure 2

Description

  Embodiments according to the present invention relate to a rotary compressor and a refrigeration cycle apparatus.

  A rotary compressor provided with two discharge ports in a compression mechanism is known.

  One discharge port (hereinafter referred to as “first discharge port”) is disposed in the vicinity of the vane. The discharge valve of the first discharge port always opens and closes.

  The discharge valve of the other discharge port (hereinafter referred to as “second discharge port”) opens only at the time of startup, and closes due to a pressure difference during rated operation. The second discharge port is provided in the vicinity of the first discharge port and at a position (a position away from the vane) closer to the rotation shaft than the first discharge port.

Japanese Utility Model Publication No.59-97292

  The volume of the second discharge port becomes an ineffective volume (dead volume) during rated operation, causing reexpansion loss and reducing efficiency.

  In addition, when the second discharge port is arranged at a position far away from the first discharge port toward the half rotation direction of the rotation shaft, the angular position at which the total discharge flow rate when the two discharge ports are combined is maximized The roller may pass through the second discharge port before the roller reaches the front. In this case, the second discharge port is closed by the roller before the roller reaches the angular position where the total discharge flow rate of the two discharge ports is maximized. Then, the second discharge port cannot exhibit its original function, that is, the function of avoiding refrigerant overcompression.

  By the way, in a facility such as a data center, it is necessary to cool equipment in the facility even in winter when the outside air temperature is low. In the refrigeration cycle apparatus under such usage conditions, free cooling operation is performed. In free cooling operation, almost no refrigerant compression is required. Therefore, a conventional refrigeration cycle apparatus that performs a free cooling operation includes a refrigerant pump for circulating the refrigerant separately from the compressor.

  Therefore, the present invention suppresses efficiency reduction due to the ineffective volume of the second discharge port, sufficiently exhibits the function of avoiding overcompression of the refrigerant, and can boost the refrigerant to the required pressure during rated operation. Therefore, the present invention proposes a rotary compressor and a refrigeration cycle apparatus that can cope with a wide operating range (operating capacity) that can circulate the refrigerant almost without increasing the pressure.

  In order to solve the above problems, a rotary compressor according to an embodiment of the present invention includes a cylinder having a cylinder chamber, a pair of blocking plates that close the cylinder, and an eccentric portion disposed in the cylinder chamber. And a rotating shaft that passes through the pair of blocking plates, a roller that is fitted in the eccentric portion and rotates eccentrically in the cylinder chamber, and a vane that partitions the cylinder chamber into a suction chamber and a compression chamber together with the roller. And at least two discharge ports that are formed in any of the pair of closing plates and the cylinder and discharge the working fluid compressed in the cylinder chamber from the cylinder chamber, the at least two discharge ports being The first discharge port is disposed closer to the vane than the second discharge port. And the second discharge port defines a rotation angle in the rotation direction of the rotation shaft when a position where the eccentric direction of the eccentric portion coincides with the direction of the vane is defined as a rotation angle of 0 degree. Is arranged at a position where the roller is disconnected from the compression chamber at any rotation angle greater than 180 degrees and 210 degrees or less.

  The refrigeration cycle apparatus according to an embodiment of the present invention includes the rotary compressor, a radiator, an expansion device, a heat absorber, the rotary compressor, the radiator, the expansion device, and the heat absorber. And a refrigerant pipe for circulating the refrigerant.

1 is a schematic diagram of a refrigeration cycle apparatus according to an embodiment of the present invention. 1 is a cross-sectional plan view of a rotary compressor according to an embodiment of the present invention. The figure which shows the relationship between the rotation angle of the rotating shaft of a rotary compressor, and compression speed. The figure which shows the influence degree to the performance fall by the rotation angle of the rotating shaft by which a 2nd discharge port disconnects with a compression chamber with a roller, and the invalid volume of a 2nd discharge port.

  Embodiments of a rotary compressor and a refrigeration cycle apparatus according to the present invention will be described with reference to FIGS. 1 to 4. In addition, the same code | symbol is attached | subjected to the same or equivalent structure in several drawing.

  FIG. 1 is a schematic diagram of a refrigeration cycle apparatus according to an embodiment of the present invention.

  As shown in FIG. 1, a refrigeration cycle apparatus 1 according to this embodiment includes a rotary compressor 2, a condenser 3 that is a radiator, an expansion device 5, an evaporator 6 that is a heat absorber, and a refrigerant pipe. 8 and. The refrigerant pipe 8 is connected to the rotary compressor 2, the condenser 3, the expansion device 5, and the evaporator 6 in order to distribute the refrigerant.

  The rotary compressor 2 according to the present embodiment includes a sealed case 11, an electric motor 12 disposed in the upper half of the sealed case 11, a compression mechanism 13 disposed in the lower half of the sealed case 11, A rotary shaft 15 that transmits the rotational driving force of the electric motor 12 to the compression mechanism 13, a main bearing 16 that rotatably supports the rotary shaft 15, and a secondary shaft that rotatably supports the rotary shaft 15 in cooperation with the main bearing 16. The bearing 17 and the accumulator 7 provided in the side part of the sealing case 11 are provided.

  The sealed case 11 has a cylindrical vertically long shape. The longitudinal direction of the sealed case 11, that is, the direction along the center line of the cylinder stands up with respect to the ground plane. The sealed case 11 includes a body portion 11a whose both ends are open, and a pair of end plates 11b that close the respective ends of the body portion 11a. Lubricating oil is stored in the sealed case 11.

  A refrigerant pipe 8 for discharging refrigerant is connected to the upper end of the sealed case 11.

  The electric motor 12 generates the rotational driving force of the compression mechanism 13. The electric motor 12 includes a stator 18 that is fixed to the inner wall of the hermetic case 11, and a rotor 19 that is surrounded by the stator 18 and provided on the rotary shaft 15.

  The rotating shaft 15 connects the electric motor 12 and the compression mechanism 13 to each other. The rotating shaft 15 transmits the power generated by the electric motor 12 to the compression mechanism 13. The rotating shaft 15 extends in the longitudinal direction of the sealed case 11. The rotating shaft 15 is disposed on the center line of the sealed case 11.

  An intermediate portion 15 a of the rotating shaft 15 is rotatably supported by the main bearing 16. A lower end portion 15 b of the rotating shaft 15 is rotatably supported by the auxiliary bearing 17. The rotating shaft 15 passes through the main bearing 16, the cylinder 21, and the sub bearing 17. In other words, the rotating shaft 15 passes through the compression mechanism 13.

  The rotating shaft 15 includes an eccentric part 22. The eccentric portion 22 is a disk or a cylinder having a center that does not coincide with the center of the rotating shaft 15.

  The compression mechanism 13 sucks and compresses the gaseous refrigerant and discharges it into the sealed case 11 when the electric motor 12 rotationally drives the rotary shaft 15.

  The compression mechanism 13 is accommodated in the sealed case 11. The compression mechanism 13 is disposed below the sealed case 11. Most of the compression mechanism 13 is immersed in the lubricating oil filled in the lower part of the sealed case 11.

  The compression mechanism 13 includes a cylinder 21 having a cylinder chamber 23, a pair of closing plates 26 and 27 that close both ends of the cylinder 21, and a roller 28 disposed in the cylinder 21.

  The cylinder 21 has a cylinder chamber 23 having a cylindrical shape or a disk shape (circular in a plan view). The center of the cylinder chamber 23 substantially overlaps the rotation center of the rotation shaft 15. The cylinder chamber 23 extends over the entire thickness of the cylinder 21 (height in the center line direction of the sealed case 11). That is, the cylinder chamber 23 penetrates the cylinder 21. The cylinder chamber 23 is a space inside the cylinder 21 and is closed by the main bearing 16 and the auxiliary bearing 17. An eccentric portion 22 of the rotating shaft 15 is disposed in the cylinder chamber 23.

  The cylinder 21 has a vane groove 29 opened in the cylinder chamber 23 and a vane back chamber 31 connected to the end of the vane groove 29 on the side far from the cylinder chamber 23. The vane back chamber 31 is opened in the sealed case 11.

  One closing plate 26, that is, the main bearing 16 closes the end surface 21 a (upper surface) of the cylinder 21 on the side close to the electric motor 12. The cylinder 21 is fixed to the inner surface of the sealed case 11 by welding. The main bearing 16 is fixed to the cylinder 21 with bolts 32. The main bearing 16 is provided with a discharge valve mechanism 33 for discharging the refrigerant compressed in the cylinder chamber 23 and a discharge muffler 35.

  The discharge muffler 35 has a discharge hole 36. The space in the discharge muffler 35 is connected to the space in the sealed case 11 through the discharge hole 36. The discharge muffler 35 covers the discharge valve mechanism 33.

  The discharge valve mechanism 33 is connected to the cylinder chamber 23. In the discharge valve mechanism 33, the pressure in the compression chamber 52 becomes higher than the pressure in the discharge muffler 35 with the compression action of the compression mechanism 13, and the differential pressure (that is, the differential pressure between the compression chamber 52 and the discharge muffler 35). When it reaches a predetermined differential pressure value, it opens, and the compressed refrigerant is discharged into the discharge muffler 35.

  The discharge valve mechanism 33 includes a discharge port 37 connected to the cylinder chamber 23, a valve body 38 that closes the discharge port 37, and a valve stopper 39 that limits the opening degree of the valve body 38. The valve body 38 is a reed valve made of a leaf spring. End portions of the valve body 38 and the valve stopper 39 are fixed to the main bearing 16.

  The other closing plate 27, that is, the auxiliary bearing 17 closes the end surface 21 b (lower surface) of the cylinder 21 on the side far from the electric motor 12. The auxiliary bearing 17 is fixed to the cylinder 21 with a bolt 41.

  The roller 28 is fitted into the eccentric portion 22 of the rotating shaft 15 and is accommodated in the cylinder chamber 23 of the cylinder 21. As the rotating shaft 15 rotates, the roller 28 rotates eccentrically in the cylinder chamber 23 while bringing a part of the outer peripheral surface of the roller 28 into contact with the inner peripheral surface of the cylinder chamber 23. Note that the roller 28 and the cylinder 21 are in indirect contact with an oil film (not shown) interposed therebetween, but for convenience of explanation, the contact through the oil film is simply expressed as “contact”. The same applies between the roller 28 and the eccentric portion 22, between the roller 28 and the main bearing 16, and between the roller 28 and the auxiliary bearing 17.

  The cylinder 21 is provided with a vane portion 45. The vane portion 45 includes a plate-like vane 46 that extends to the same extent as the height (thickness) of the cylinder 21, and a coil spring 47 that generates a spring force that presses the tip of the vane 46 against the outer peripheral surface of the roller 28. I have.

  The vane 46 is disposed in the vane groove 29 of the cylinder 21. The vane 46 advances / retreats (in / out) from the vane groove 29 into the cylinder chamber 23 by the spring force of the coil spring 47, the pressure of the sealed case 11, and the force acting from the roller 28.

  The tip of the vane 46 has a substantially arc shape. The tip of the vane 46 protrudes into the cylinder chamber 23 and is in line contact with the outer peripheral surface of the circular roller 28 via an oil film regardless of the rotation angle (eccentric rotation position) of the roller 28. The vane 46 is in contact with the roller 28 and partitions the cylinder chamber 23 into a suction chamber and a compression chamber.

  The coil spring 47 is accommodated in a spring accommodation hole 48 formed in the outer peripheral wall of the cylinder 21. The spring accommodation hole 48 reaches the front of the cylinder chamber 23 through the vane back chamber 31. One end of the coil spring 47 is pressed against the vane 46, and the other end is pressed against the inner peripheral surface of the sealed case 11.

  Since the vane back chamber 31 is open in the sealed case 11, the pressure in the sealed case 11 acts on the back surface of the vane 46. The coil spring 47 has a low pressure in the sealed case 11, and the pressure in the sealed case 11 alone does not sufficiently press the vane 46 against the roller 28, and the cylinder chamber 23 is partitioned into a suction side and a compression side. When this is not possible, the pressing force of the vane 46 is assisted.

  A refrigerant pipe 8 for sucking refrigerant is connected to the upper portion of the accumulator 7. A suction pipe 8 a is provided through the bottom of the accumulator 7. The suction pipe 8 a is provided in the cylinder 21 through the sealed case 11 of the rotary compressor 2, and is connected to a suction hole 49 connected to the cylinder chamber 23.

  The compression mechanism 13 of the rotary compressor 2 according to this embodiment will be described in more detail.

  FIG. 2 is a cross-sectional plan view of the rotary compressor according to the embodiment of the present invention.

  FIG. 2 shows a state in which the closing plate 26 is removed from the compression mechanism 13.

  As shown in FIG. 2, the cylinder chamber 23 of the compression mechanism 13 of the rotary compressor 2 according to this embodiment is partitioned into a suction chamber 51 and a compression chamber 52 by a roller 28 and a vane 46. The working fluid (refrigerant) sucked into the cylinder chamber 23 is compressed in the cylinder chamber 23 by the eccentric rotation of the roller 28 and the forward / backward movement of the vane 46.

  The cylinder 21 has a suction hole 49 extending in the radial direction of the cylinder 21. The suction hole 49 is disposed immediately after the vane portion 45 (or the vane groove 29 or the vane 46) (right side of the vane groove 29 in FIG. 2) in the rotation direction of the roller 28 (direction of arrow R in FIG. 2). . The outer end of the suction hole 49 in the radial direction of the cylinder 21 is connected to the suction pipe 8a. The inner end of the suction hole 49 in the radial direction of the cylinder 21 is connected to the cylinder chamber 23.

  The discharge valve mechanism 33 of the main bearing 16 has at least two discharge ports 37 connected to the cylinder chamber 23. The at least two discharge ports 37 include a first discharge port 55 and a second discharge port 56. Each discharge port 37 is a circular hole that penetrates the main bearing 16. Each discharge port 37 passes through the main bearing 16 in the longitudinal direction (extending direction) of the rotating shaft 15. Each discharge port 37 discharges the working fluid compressed in the cylinder chamber 23 from the cylinder chamber 23 to the outside of the cylinder chamber 23, that is, to the space inside the sealed case 11.

  Here, the position where the eccentric direction of the eccentric portion 22 (the direction from the rotation center of the rotating shaft 15 toward the center of the eccentric portion) coincides with the direction of the vane portion 45 (or the vane groove 29 or the vane 46) (advance / retreat direction). A rotation angle is defined in the rotation direction of the rotation shaft 15 and the roller 28 (arrow R direction in FIG. 2) with the rotation angle (angular position) = 0 degree. The rotation angle is also called a crank angle.

  One of the two discharge ports 37, that is, the first discharge port 55 is arranged closer to the vane portion 45 than the second discharge port 56. The first discharge port 55 is disposed immediately before reaching the vane portion 45 (or the vane groove 29 or the vane 46) in the rotation direction R of the roller 28 (on the left side of the vane groove 29 in FIG. 2). In other words, the angular position (rotation angle) at which the first discharge port 55 is disposed is larger than the angular position (rotation angle) at which the second discharge port 56 is disposed, and the working fluid flows from the compression chamber 52 to the suction chamber 51. As long as there is no leakage, the rotation angle is approximately 360 degrees, that is, very close to the vane 46. The angular position (rotation angle) at which the first discharge port 55 is disposed is immediately before the so-called top dead center.

  The other of the two discharge ports 37, that is, the second discharge port 56, is connected to the compression chamber 52 by the roller 28 at a rotation angle θ of the rotation shaft 15 larger than 180 degrees and any rotation angle of 210 degrees or less. It is arranged at the position where is cut off. Note that the second discharge port 56a in FIG. 2 is disposed at a position where the roller 28 is disconnected from the compression chamber 52 when the rotation angle θ of the rotation shaft 15 slightly exceeds 180 degrees. The second discharge port 56 is shown, and the second discharge port 56b is arranged at a position where the rotation angle θ of the rotation shaft is 210 degrees and the roller 28 is disconnected from the compression chamber 52. In this case, the second discharge port 56 is shown.

  Here, “the connection between the compression chamber 52 and the second discharge port 56 is broken by the roller 28” means a roller that rotates eccentrically in the cylinder chamber 23 in plan view (in the direction of the rotation center line of the rotary shaft 15). 28 represents a position where the second discharge port 56 is overlapped with the second discharge port 56, and the second discharge port 56 is separated from the compression chamber 52 of the cylinder chamber 23, is edged, cut off, disconnected, or disconnected. Note that, as the eccentric rotation of the roller 28 proceeds, the second discharge port 56 is eventually connected to the suction chamber 51.

  The first valve body 57 that closes the first discharge port 55 and the second valve body 58 that closes the second discharge port 56 have the pressure in the compression chamber 52 of the cylinder chamber 23 in the discharge muffler 35 due to the compression action of the compression mechanism 13. When the pressure difference (that is, the pressure difference between the compression chamber 52 and the inside of the discharge muffler 35) reaches a predetermined pressure difference, the pressure is released and the compressed refrigerant is discharged into the discharge muffler 35. To do. The first valve body 57 that closes the first discharge port 55 is opened when the differential pressure between the space in the compression chamber 52 and the discharge muffler 35 reaches a predetermined differential pressure value at any compression ratio.

  Therefore, the first discharge port 55 is opened when the pressure difference between the compression chamber 52 and the space in the discharge muffler 35 reaches a predetermined differential pressure value due to the compression action of the compression mechanism 13, so that the inside of the cylinder chamber 23 is opened. Almost all of the compressed refrigerant is discharged.

  On the other hand, in the second discharge port 56, the pressure in the compression chamber 52 is increased in the discharge muffler 35 due to the compression action of the compression mechanism 13 until the second discharge port 56 b is disconnected from the compression chamber 52 by the roller 28. When the pressure reaches a predetermined pressure difference value, the pressure is released and the compressed refrigerant in the cylinder chamber 23 is discharged. When the second discharge port 56 is disconnected from the compression chamber 52 by the roller 28, the second discharge port 56 is blocked by the roller 28 or connected to the suction chamber 51 and closed. (The second valve body 58 is closed). Furthermore, even if the pressure of the compression chamber 52 does not become higher than the pressure of the space in the discharge muffler 35 by the time the roller 28 is disconnected from the compression chamber 52 by the roller 28, If the differential pressure does not reach a predetermined differential pressure value, it remains closed.

  The passage sectional area of the second discharge port 56 is larger than the passage sectional area of the first discharge port 55. The passage sectional areas of the two discharge ports 37, that is, the first discharge port 55 and the second discharge port 56 may be the same. In other words, the diameters of the first discharge port 55 and the second discharge port 56 may be the same.

  The spring constant of the second valve body 58 that closes the second discharge port 56 is made smaller than the spring constant of the first valve body 57 that closes the first discharge port 55. The spring constant of the second valve body 58 that closes the second discharge port 56 may be the same as the spring constant of the first valve body 57 that closes the first discharge port 55.

  Note that there may be three or more discharge ports 37. In that case, the third or more discharge ports 37, that is, the discharge ports 37 after the third discharge port (not shown) are provided in a range where the rotation angle is smaller than that of the second discharge port 56.

  Next, the setting of the range (greater than 180 degrees and less than 210 degrees) of the rotation angle θ (angular position) of the rotary shaft 15 where the second discharge port 56 is disconnected from the compression chamber 52 by the roller 28 will be described in more detail. explain.

  First, the setting of the lower limit of the range of the rotation angle θ of the rotating shaft at which the second discharge port 56 is disconnected from the compression chamber 52 by the roller 28 will be described.

  FIG. 3 is a diagram showing the relationship between the rotation angle of the rotary shaft of the rotary compressor and the compression speed.

  The horizontal axis in FIG. 3 indicates the rotation angle (= angle position) of the rotary shaft 15. 3 represents the compression speed of the working fluid (refrigerant) in the cylinder chamber 23 (compression chamber 52) accompanying the eccentric rotation of the roller 28, and the ratio to the maximum value (rotation angle = compression speed at 180 degrees). Show.

  As shown in FIG. 3, the compression speed of the working fluid (refrigerant) in the cylinder chamber 23 accompanying the eccentric rotation of the roller 28 becomes maximum when the rotation angle of the rotating shaft 15 reaches 180. When the rotation angle is in the range of 0 ° ≦ rotation angle <180 °, the compression speed gradually increases. When the rotation angle is in the range of 180 degrees <rotation angle ≦ 360 degrees, the compression speed gradually decreases.

  In both the first discharge port 55 and the second discharge port 56, the discharge flow rate when the valve body is open is equal to the compression speed.

  Here, when the second discharge port 56 is disposed at a position where the connection with the compression chamber 52 is disconnected by the roller 28 when the rotation angle θ of the rotation shaft 15 is smaller than 180 degrees, the second discharge port 56 is provided. Is closed before the discharge flow rate becomes maximum (the roller 28 cuts the edge from the compression chamber 52 or is cut off, cut off, and isolated). Then, after the second discharge port 56 is closed, the compressed refrigerant is discharged only from the first discharge port 55 in the process in which the roller 28 rotates eccentrically toward the maximum compression speed (maximum discharge flow rate). That is, the discharge effect of the compressed refrigerant by the second discharge port 56 (a function of avoiding overcompression of the refrigerant) is not exhibited.

  Therefore, the second discharge port 56 in the present embodiment is disposed at a position where the connection with the compression chamber 52 is broken by the roller 28 when the rotation angle θ of the rotation shaft 15 is larger than 180 degrees. Therefore, the rotary compressor 2 according to the present embodiment sufficiently exhibits the function of avoiding overcompression of the refrigerant and can boost the refrigerant to the required pressure during rated operation, while almost boosting the refrigerant. The discharge effect of the compressed refrigerant by the second discharge port 56 (the function of avoiding overcompression of the refrigerant) can be exhibited in a wide range of operation (operating capacity) that can be simply circulated without causing the refrigerant to circulate.

  On the other hand, under the condition that the refrigerant is boosted to the required pressure in the rated operation, the second discharge port 56 becomes an invalid volume (dead volume), and the second discharge port 56 is connected to the suction chamber 51 when the second discharge port 56 is connected to the suction chamber 51. The high-pressure refrigerant in the discharge port 56 may be re-expanded in the suction chamber 51 and cause a performance deterioration called re-expansion loss.

  FIG. 4 is an example of the rotary compressor according to the present embodiment, and the rotary shaft at which the second discharge port is disconnected from the compression chamber by the roller in a high compression ratio condition where the re-expansion loss is the largest. It is a figure which shows the relationship between this rotation angle and the influence degree (invalid volume influence degree) to the performance fall by the invalid volume of a 2nd discharge port.

  The degree of influence on the performance degradation due to the invalid volume of the second discharge port 56 is hereinafter referred to as “invalid volume influence degree”.

  The horizontal axis in FIG. 4 indicates the rotation angle of the rotary shaft 15 at which the second discharge port 56 is disconnected from the compression chamber 52 by the roller 28. The vertical axis in FIG. 4 indicates the invalid volume influence degree.

  Here, the ineffective volume influence degree is expressed by [Equation 1].

  The pressure P represents the pressure in the compression chamber 52 at the rotation angle. The suction pressure Ps represents the suction pressure of the cylinder chamber 23 (suction chamber 51). n is a polytropic index. The polytropic index n in FIG. 4 is 1.3.

  [Equation 1] indicates that the working fluid (refrigerant) in the second discharge port 56 re-expands from the pressure P in the compression chamber 52 to the suction pressure Ps, so that the working fluid sucked into the suction chamber 51 flows backward. This means that the true suction volume decreases.

  [Equation 1] is an expression that is actually expressed by [Equation 2] and is omitted by assuming that (invalid volume Vtop2 ÷ excluded volume V) of [Equation 2] is constant.

  The invalid volume Vtop2 represents the volume (invalid volume) of the second discharge port 56. The excluded volume V represents the excluded volume (suction volume) of the cylinder chamber 23.

  As shown in FIG. 4, the ineffective volume influence degree is about half (about 50%) of the value obtained by subtracting 1 from the maximum value in the vicinity of the rotation angle θ = 210 degrees. When the ineffective volume influence degree exceeds 50% (about half of the value obtained by subtracting 1 from the maximum value), the performance degradation due to the ineffective volume during the rated operation becomes too large rather than the efficiency improvement during the low compression ratio operation. Therefore, the second discharge port 56 is blocked from the compression chamber 52 at a rotation angle θ = 210 degrees or less without the invalid volume influence degree exceeding 50% (about half of the value obtained by subtracting 1 from the maximum value). It is desirable.

  That is, in the rotary compressor 2 according to the present embodiment, the range of the rotation angle θ (angular position) of the rotary shaft 15 where the second discharge port 56 is disconnected from the compression chamber 52 by the roller 28 from 180 degrees. By setting it to any one of 210 degrees or less (180 degrees <θ ≤ 210 degrees), the effect of discharging the compressed refrigerant by the second discharge port 56 is sufficiently exhibited, and the degree of influence on the performance degradation due to the invalid volume. Can be minimized.

  In the rotary compressor 2 and the refrigeration cycle apparatus 1 according to the present embodiment, the rotation angle θ of the rotary shaft 15 is substantially any rotation angle greater than 180 degrees and 210 degrees or less, and the compression chamber 52 and The second discharge port 56 is provided at a position where the connection is disconnected. Therefore, the rotary compressor 2 and the refrigeration cycle apparatus 1 can minimize the degree of influence on the performance degradation due to the invalid volume during rated operation, and at the same time the refrigerant is simply circulated without increasing the pressure of the refrigerant. The over-compression avoidance function can be fully demonstrated, and the discharge effect of the compressed refrigerant (refrigerant over-compression avoidance function) by the second discharge port 56 can be demonstrated over a wide range of operation (operation capability), and is invalid The degree of influence on performance degradation due to volume can be minimized.

  The rotary compressor 2 and the refrigeration cycle apparatus 1 according to the present embodiment include a second discharge port 56 having a passage cross-sectional area larger than the passage cross-sectional area of the first discharge port 55. Therefore, the rotary compressor 2 and the refrigeration cycle apparatus 1 can achieve higher efficiency by minimizing over-compression in a low compression ratio operation where the flow rate of the discharged working fluid (refrigerant) is larger than that in a high compression ratio operation.

  Furthermore, the rotary compressor 2 and the refrigeration cycle apparatus 1 according to the present embodiment have the second valve body of the second discharge port 56 having a spring constant smaller than the spring constant of the first valve body 57 of the first discharge port 55. 58. Therefore, the rotary compressor 2 and the refrigeration cycle apparatus 1 can obtain high efficiency by minimizing overcompression in a low compression ratio operation in which the flow rate of discharged working fluid (refrigerant) is larger than that in a high compression ratio operation. Generally, when the spring constant of the valve body of the discharge port is small, the performance and reliability are deteriorated due to the delay in closing the discharge port (valve) at a load exceeding the rating. However, in the rotary compressor 2 and the refrigeration cycle apparatus 1 according to the present embodiment, the opening and closing of the second discharge port 56 at a load exceeding the rating is not performed, and performance and reliability due to a delay in closing the second discharge port 56 are reduced. There is no decline.

  Therefore, according to the rotary compressor 2 and the refrigeration cycle apparatus 1 including the rotary compressor 2 of the present embodiment, the efficiency reduction due to the invalid volume of the second discharge port 56 is suppressed, and the refrigerant over-compression avoidance function In addition, the refrigerant can be boosted to the required pressure during rated operation, while the refrigerant can be simply circulated with almost no pressure increase.

  In the present embodiment, the first discharge port 55 and the second discharge port 56 are provided in the main bearing 16, but the first discharge port 55 and the second discharge port 56 are provided in the auxiliary bearing 17. Alternatively, the cylinder 21 may be provided. Further, the first discharge port 55 may be provided in the main bearing 16, and the second discharge port 56 may be provided in the auxiliary bearing 17. As described above, the first discharge port 55 and the second discharge port 56 may be provided in any one of the main bearing 16, the auxiliary bearing 17, and the cylinder 21.

  In the present embodiment, the roller 28 and the vane 46 are separated from each other. However, the present invention can also be applied to a swing type compressor in which the roller 28 and the vane 46 are integrated.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Refrigeration cycle apparatus, 2 ... Rotary compressor, 3 ... Condenser, 5 ... Expansion apparatus, 6 ... Evaporator, 7 ... Accumulator, 8 ... Refrigerant pipe, 8a ... Suction pipe, 11 ... Sealing case, 12 ... Electric motor , 13 ... compression mechanism, 15 ... rotating shaft, 15a ... intermediate portion, 15b ... lower end, 16 ... main bearing, 17 ... sub-bearing, 11a ... trunk, 11b ... end plate, 18 ... stator, 19 ... rotor, 21 ... Cylinder, 21a, 21b ... End face of cylinder, 22 ... Eccentric part, 23 ... Cylinder chamber, 26, 27 ... Blocking plate, 28 ... Roller, 29 ... Vane groove, 31 ... Vane back chamber, 32 ... Bolt, 33 ... Discharge valve mechanism, 35 ... Discharge muffler, 36 ... Discharge hole, 37 ... Discharge port, 38 ... Valve body, 39 ... Valve stopper, 41 ... Bolt, 45 ... Vane part, 46 ... Vane, 47 ... Coil spring, 48 ... Spring Receiving hole, 9 ... suction hole, 51 ... suction chamber, 52 ... compression chamber, 55 ... first discharge port, 56, 56a, 56b ... second discharge port, 57 ... first valve body 58 ... second valve body.

Claims (4)

A cylinder having a cylinder chamber;
A pair of closing plates for closing the cylinder;
A rotating shaft having an eccentric portion disposed in the cylinder chamber and penetrating the pair of blocking plates;
A roller fitted in the eccentric part and eccentrically rotated in the cylinder chamber;
A vane that partitions the cylinder chamber into a suction chamber and a compression chamber together with the roller;
Having at least two discharge ports that are formed on either of the pair of closing plates and the cylinder and discharge the working fluid compressed in the cylinder chamber from the cylinder chamber;
The at least two discharge ports include a first discharge port and a second discharge port;
The first discharge port is disposed closer to the vane than the second discharge port;
In the second discharge port, when the rotation angle is defined in the rotation direction of the rotation shaft with the position where the eccentric direction of the eccentric portion coincides with the direction of the vane as a rotation angle of 0 degrees, the rotation angle of the rotation shaft is 180 degrees. A rotary compressor disposed at a position where the roller is disconnected from the compression chamber at any rotation angle greater than 200 degrees and at any rotation angle of 210 degrees or less. The rotary compressor according to claim 1, wherein a passage sectional area of the second discharge port is larger than a passage sectional area of the first discharge port. The rotary compressor according to claim 1 or 2, wherein a spring constant of a valve body that closes the second discharge port is smaller than a spring constant of a valve body that closes the first discharge port. The rotary compressor according to any one of claims 1 to 3,
A radiator,
An expansion device;
A heat sink,
A refrigeration cycle apparatus comprising: a refrigerant pipe that connects the rotary compressor, the radiator, the expansion device, and the heat absorber to distribute the refrigerant.

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