GB2581613A - Scroll compressor - Google Patents

Abstract

This scroll compressor is provided with: a fixed scroll; a rocking scroll that forms a compression part together with the fixed scroll; a frame that holds the rocking scroll; a sealed container that accommodates the fixed scroll, the rocking scroll, and the frame; a suction pipe that suctions a gas refrigerant into the sealed container; and an injection pipe that injects a liquid refrigerant or a two-phase refrigerant into the sealed container, wherein a refrigerant suction path that guides the refrigerant, injected from the injection pipe, to a suctioning section of the compression part is formed in the frame.

Description

DESCRIPTION Title of Invention

SCROLL COMPRESSOR

Technical Field

[0001] The present disclosure relates to a scroll compressor to be mounted on an air-conditioning apparatus or a refrigeration apparatus.

Background Art

[0002] In the case where a compressor is used under conditions that the discharge temperature of the compressor rises, such as the condition in which outside air has a low temperature or R32 refrigerant is used, the compressor may be required to include a mechanism that reduces the degree to which the discharge temperature rises. As such a mechanism, a suction injection mechanism is used. In the suction injection mechanism, part of refrigerant that has flowed out of a condenser is bypassed and made to flow to a circuit located on a suction side of the compressor, and the temperature of a suction gas in the compressor is lowered, thereby reducing the degree to which the discharge temperature of the compressor rises. In an existing suction injection mechanism, an injection port is provided in an intermediate chamber located in an intermediate stage of a compression step using a spiral and refrigerant is injected via the injection port (see, for example, Patent Literature 1).

Citation List Patent Literature [0003] Patent Literature 1: Japanese Unexamined Patent Application Publication No 08-

Summary of Invention

Technical Problem [0004] In a compressor described in Patent Literature 1, refrigerant is injected into a compression chamber via the injection port provided in the intermediate chamber located in the intermediate stage of the compression step. In the case where the pressure of the compression chamber into which the refrigerant is to be injected is higher than the pressure of the refrigerant, the refrigerant being compressed in the compression chamber may flow out thereof through of the injection port. In this case, since a component that allows the refrigerant to be injected is provided outside the compressor, that is, the internal space of the component is located out the compressor chamber, the volume of this space is a dead volume that does not contribute to compression of the refrigerant in a compression process. Furthermore, in the compressor of Patent Literature 1, since refrigerant is injected via the injection port provided in the intermediate chamber located in the intermediate stage of the compression step, refrigerant having different pressures is mixed, and may thus cause a mixing loss.

[0005] Embodiments of the present disclosure are provided to solve to such a problem as described above, and the present disclosure relates to a scroll compressor that reduces the degree to which the discharge temperature of the compressor rises without causing a mixing loss or a loss due to a dead volume of the compressor.

Solution to Problem [0006] A scroll compressor of an embodiment according to the present disclosure includes a fixed scroll, an orbiting scroll, a frame, a sealed container, a suction pipe, and an injection pipe. The orbiting scroll forms together with the fixed scroll, a compression unit. The frame holds the orbiting scroll. The sealed container accommodates the fixed scroll, the orbiting scroll, and the frame. The suction pipe allows gas refrigerant to be sucked into the sealed container. The injection pipe allows liquid refrigerant or two-phase refrigerant to be injected into the sealed container. In the frame, a refrigerant suction passage is provided to guide, to a suction portion of the compression unit, the refrigerant injected from the injection pipe.

Advantageous Effects of Invention [0007] In the scroll compressor of the embodiment according to the present disclosure, the refrigerant suction passage that guides the refrigerant injected from the injection pipe to the suction portion of the compression unit is provided in the frame. Thus, liquid refrigerant or two-phase refrigerant injected from the injection pipe is guided to the compression unit through the refrigerant suction passage formed in the frame. Therefore, in the scroll compressor, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to a dead volume of the compressor or a mixing loss.

Brief Description of Drawings

[0008] [Fig. 1] Fig. 1 is a schematic vertical sectional view of a scroll compressor according to Embodiment 1 of the present disclosure.

[Fig. 2] Fig. 2 is a schematic cross-sectional view of the scroll compressor that is taken along line A-A in Fig. 1.

[Fig. 3] Fig. 3 is a schematic vertical sectional view of the compressor illustrating flow of refrigerant injected from an injection pipe of the scroll compressor according to Embodiment 1 of the present disclosure.

[Fig. 4] Fig. 4 is an enlarged schematic vertical sectional view of a portion B of a modification of the scroll compressor according to Embodiment 1 of the present

disclosure as illustrated in Fig. 1.

[Fig. 5] Fig. 5 is an enlarged schematic vertical sectional view of a portion B of another modification of the scroll compressor according to Embodiment 1 of the present disclosure as illustrated in Fig. 1.

[Fig. 6] Fig. 6 is a schematic vertical sectional view of a scroll compressor according to Embodiment 2 of the present disclosure.

[Fig. 7] Fig. 7 is a schematic vertical sectional view of the scroll compressor 100 that is taken along line C-C in Fig. 6.

[Fig. 8] Fig. 8 is an enlarged schematic vertical sectional view of a modification of the scroll compressor according to Embodiment 2 of the present disclosure as illustrated in Fig. 6.

[Fig. 9] Fig. 9 is an enlarged schematic vertical sectional view of another modification of the scroll compressor according to Embodiment 2 as illustrated in Fig. 6. [Fig. 10] Fig. 10 is a schematic vertical sectional view of a scroll compressor according to Embodiment 3 of the present disclosure.

[Fig. 11] Fig. 11 is an enlarged schematic vertical sectional view of a portion D of the scroll compressor as illustrated in Fig. 10.

[Fig. 12] Fig. 12 is a schematic cross sectional view of the scroll compressor that is taken along line E-E in Fig. 11.

[Fig. 13] Fig. 13 is an enlarged schematic vertical sectional view of a modification of the scroll compressor according to Embodiment 3 of the present disclosure as illustrated in Fig. 10.

[Fig. 14] Fig. 14 is a schematic cross sectional view of the scroll compressor that is taken along line F-F in Fig. 13.

[Fig. 15] Fig. 15 is a schematic vertical sectional view of a scroll compressor according to Embodiment 4 of the present disclosure.

[Fig. 16] Fig. 16 is an enlarged schematic vertical sectional view of a portion G of the scroll compressor as illustrated in Fig. 15.

[Fig. 17] Fig. 17 is a schematic cross sectional view of the scroll compressor that is taken along line H-H in Fig. 16.

[Fig. 18] Fig. 18 is an enlarged schematic vertical sectional view of a modification of the scroll compressor according to Embodiment 4 of the present disclosure as illustrated in Fig. 15.

[Fig. 19] Fig. 19 is a schematic cross sectional view of the scroll compressor that is taken along line I-I in Fig. 18.

Description of Embodiments

[0009] A scroll compressor 100 according to each of embodiments of the present disclosure will be described with reference to the drawings. In each of the figures, components that are the same as or equivalent to those in a previous figure are denoted by the same reference signs. The same is true of the entire text of the following description of the embodiments. Furthermore, the configurations of components as described in the specification are merely examples, and the configurations of the components are not limited to those as described in the specification. Also, the relationship in size between components as illustrated in the figures may be different from that between actual components. Regarding the embodiments, in order that they be easily understood, terms related to directions (such as "upper", "lower", "right", "left", front", and "rear") are used as appropriate. However, these terms are used only for explanation, that is, they do not limit the embodiments.

[0010] Embodiment 1 [Scroll Compressor 100] Fig. 1 is a schematic vertical sectional view of a scroll compressor 100 according to Embodiment 1 of the present disclosure. Fig. 2 is a schematic vertical sectional view of the scroll compressor 100 that is taken along line A-A in Fig. 1. The scroll compressor 100 will be described with reference to Figs. 1 and 2. The scroll compressor 100 sucks low-temperature, low-pressure refrigerant that circulates in a refrigeration cycle circuit, compresses the refrigerant into high-temperature, high-pressure refrigerant, and discharges the high-temperature high-pressure refrigerant.

The scroll compressor 100 is provided with a sealed container 4 including a middle shell 1, an upper shell 2, and a lower shell 3 that form an outer shell of the sealed container 4. The scroll compressor 100 includes a compression unit 8 that compresses the refrigerant in the sealed container 4, and a rotation driving unit 11 that drives the compression unit 8. Furthermore, the scroll compressor 100 includes a frame 7 that is fixed to the sealed container 4 and accommodates the compression unit 8, and an injection pipe 20 connected to a circumferential wall of the sealed container 4 to allow liquid refrigerant or two-phase refrigerant to be injected into the sealed container 4. [0011] (Sealed Container 4) The sealed container 4 has a cylindrical circumferential wall, and forms the outer shell of the scroll compressor 100. In the sealed container 4, the compression unit 8, the rotation driving unit 11 and a main shaft 21 are provided. The sealed container 4, as described above, includes the middle shell 1, the upper shell 2, and the lower shell 3; and the middle shell 11 is cylindrical, the upper shell 2 is located above middle shell 1, and the lower shell 3 is located below the middle shell 1. In the sealed container 4, a suction pipe 12 for use in suction of refrigerant from the outside of sealed container 4 is connected to a side wall of the middle shell 1. To be more specific, the suction pipe 12 allows gas refrigerant to be sucked into the sealed container 4. The suction pipe 12 is connected to the side wall of the middle shell 1 of the sealed container 4, and the suction pipe 12 communicates with a low-pressure space 28 in the sealed container 4 between the frame 7 and the rotation driving unit 11. Space in the inside of the upper shell 2 of the sealed container 4 is a high-pressure space 17, and a discharge pipe 13 is connected to an upper portion of the sealed container 4 to allow the refrigerant compressed by the compression unit 8 to be discharged. Furthermore, in the sealed container 4, a sub frame 15 is provided below the rotation driving unit 11, and fixed to an inner circumferential surface of the middle shell 1. In addition, the sealed container 4 includes an oil reservoir 14 to store refrigerating machine oil in an internal space of the lower shell 3. It should be noted that the middle shell 1 corresponds to "circumferential wall" in the embodiments of the present disclosure.

[0012] The injection pipe 20 is connected to the side wall of the middle shell 1 of the sealed container 4. The injection pipe 20 allows the low-temperature liquid refrigerant or the two-phase refrigerant including liquid refrigerant to be injected into the sealed container 4. The injection pipe 20 communicates with the low-pressure space 28 in the sealed container 4, which is located between the frame 7 and the rotation driving unit 11. The injection pipe 20 is connected to the cylindrical middle shell 1 such that they are perpendicular to each other, that is, the injection pipe 20 is connected to the cylindrical middle shell 1 in a radial direction of the cylindrical middle shell 11 and a horizontal direction. A direction in which the refrigerant flows out of the injection pipe 20 is not limited to a direction perpendicular to the middle shell 1, and the injection pipe may be connected to the middle shell 1 such that the injection pipe 20 extends diagonally to a vertical direction toward a refrigerant suction passage 29 that will be described later. The injection pipe 20 is connected to the sealed container 4 at a position that is different from the position of the suction pipe 12 in a circumferential direction of the sealed container 4.

[0013] (Compression Unit 8) The compression unit 8 is provided in the sealed container 4 to compress a fluid (for example, the refrigerant) sucked from the suction pipe 12 into the sealed container 4. The compression unit 8 includes a fixed scroll 5 fixed to the sealed container 4, and an orbiting scroll 6 that orbits (that is, makes orbital motion) relative to the fixed scroll 5. The fixed scroll 5, for example, is fixed to an upper end of the frame 7 by bolts in such a manner as to close a cylindrical opening portion of the frame 7, whereby the fixed scroll 5 is fixed to the sealed container 4. That is, the sealed container 4 houses the fixed scroll 5, the orbiting scroll 6, and the frame 7. It should be noted that although it is described above that the fixed scroll 5 is fixed to the frame 7, the fixed scroll 5 can be fixed directly to the middle shell 1 of the sealed container 4 without being fixed to the frame 7. The fixed scroll 5 and the orbiting scroll 6 are combined such that a fixed scroll spiral 5b of the fixed scroll 5 and an orbiting scroll spiral 6b of the orbiting scroll 6 mesh with each other. In the compression unit 8, a compression chamber 27 is provided between the fixed scroll spiral 5b and the orbiting scroll spiral 6b to compress the refrigerant. Furthermore, in the compression unit 8, a suction portion 35 is provided between the fixed scroll spiral 5b and orbiting scroll spiral 6b and the frame 7 in such a manner to communicate with the compression chamber 27.

[0014] The frame 7 is cylindrically formed, fixed to the sealed container 4 to accommodate the compression unit 8, and holds the orbiting scroll 6. The frame 7 accommodates the fixed scroll 5 and the orbiting scroll 6 that form the compression chamber 27, and bears a thrust bearing load that is applied during an operation of the compressor via a thrust bearing surface 6d of the orbiting scroll 6. In the frame 7, the refrigerant suction passage 29 is provided to guide the refrigerant injected from the injection pipe 20 to the suction portion 35 of the compression unit 8. The refrigerant suction passage 29 is a flow passage that extends through the frame 7 in the vertical direction, causes the low-pressure space 28 and the suction portion 35 to communicate with each other, and guides refrigerant gas that is present in the low-pressure space 28 to the compression chamber 27. That is, in the frame 7, at least one refrigerant suction passage 29 is provided to cause the compression unit 8 to communicate with the low-pressure space 28 provided between the compression unit 8 and the rotation driving unit 11. Although at least one refrigerant suction passage 29 is provided in a circumferential direction of the frame 7, a plurality of refrigerant suction passages may be formed. In the scroll compressor 100, as illustrated in Fig. 2, a position at which the at least one refrigerant suction passage 29 is provided in the frame 7 is the same as in the circumferential direction to a position at which the injection pipe 20 is connected in the middle shell 1 of the sealed container 4. An inlet 29A of the refrigerant suction passage 29 is located between a central axis 0 of the sealed container 4 and the injection pipe 20 as viewed in plan view. That is, in the scroll compressor 100, the inlet 29A of the at least one refrigerant suction passage 29 and an outlet 20A of the injection pipe 20 are located in the same straight line in a radial direction of the sealed container 4 from the central axis 0 of the sealed container 4 toward the middle shell 1 as viewed in plan view. Referring back to Fig. 1, the outlet 20A of the injection pipe 20 is provided in part of the middle shell 1 that is located between the compression unit 8 and the rotation driving unit 11 and closer to the compression unit 8. Between the orbiting scroll 6 and the frame 7, an Oldham ring 19 is provided to regulate rotation of the orbiting scroll 6 to the fixed scroll 5 around an axis of the orbiting scroll 5. The Oldham ring 19 is used to stop the rotation of the orbiting scroll 6 around the axis thereof during the orbital motion of the orbiting scroll 6.

[0015] (Fixed Scroll 5) The fixed scroll 5 compresses together with the orbiting scroll 6, the refrigerant.

The fixed scroll 5 is located opposite to the orbiting scroll 6. The fixed scroll 5 includes a flat fixed scroll base plate 5a and the fixed scroll spiral 5b, which is a spiral protrusion formed to protrude from the fixed scroll base plate 5a to the orbiting scroll 6.

[0016] The fixed scroll base plate 5a forms along with the fixed scroll spiral 5b and the orbiting scroll 6, the compression chamber 27. The fixed scroll base plate 5a is fixed in the sealed container 4 such that an outer circumferential surface of the fixed scroll base plate 5a faces the inner circumferential surface of the middle shell 1, and an outer circumferential area of a lower end surface of the fixed scroll base plate 5a faces the upper portion of the frame 7. In a central portion of the fixed scroll base plate 5a, a discharge port 16 is provided and extends through the fixed scroll base plate 5a to allow high-temperature, high-pressure refrigerant gas obtained through compression to be discharged. On an outlet side of the discharge port 16, a discharge valve 18 is provided. The discharge valve 18 has a reed valve structure to prevent backf low of the refrigerant from the high-pressure space 17 toward the discharge port 16. When the pressure of the refrigerant is smaller than a preset pressure, the discharge valve 18 is caused to close the discharge port 16 to prevent the refrigerant from flowing from the compression chamber 27 toward the discharge pipe 13, and when the pressure of the refrigerant is higher than or equal to the preset pressure, the discharge valve is caused to open the discharge port 16.

[0017] The fixed scroll spiral 5b compresses together with the orbiting scroll spiral 6b of the orbiting scroll 6, the refrigerant. Furthermore, the fixed scroll spiral 5b defines together with the fixed scroll base plate 5a and the orbiting scroll 6, the compression chamber 27, the volume of which varies in accordance with the orbital motion of the orbiting scroll 6. Furthermore, the fixed scroll spiral 5b defines together with the frame 7 and the orbiting scroll 6, the suction portion 35. The fixed scroll base plate 5a is formed such that the cross section of the fixed scroll base plate 5a is spiral.

[0018] (Orbiting Scroll 6) The orbiting scroll 6 forms together with the fixed scroll 5, the compression unit 8, and compresses the refrigerant together with the fixed scroll 5. The orbiting scroll 6 is eccentric to the fixed scroll 5, and the orbiting scroll 6 and fixed scroll 5 have respective spiral protrusions, which are combined with each other to define the compression chamber 27. The orbiting scroll 6 is provided opposite to the fixed scroll 5. The orbiting scroll 6 includes a flat orbiting-scroll base plate 6a and the orbiting scroll spiral 6b, which is a spiral protrusion formed to protrude from the orbiting-scroll base plate 6a to the fixed scroll 5. The orbiting scroll 6 makes the orbital motion relative to the fixed scroll 5 without rotating around the axis of the orbiting scroll 6, because of the Oldham ring 19 that prevents the orbiting scroll 6 from rotating around the axis thereof.

[0019] The orbiting-scroll base plate 6a defines together with the orbiting scroll spiral 6b and the fixed scroll 5, the compression chamber 27. The orbiting-scroll base plate 6a is a disk-shaped member, and makes orbital motion in the frame 7 in accordance with the rotation of the main shaft 21. The axial thrust load of the orbiting scroll 6 is borne by the frame 7. A wall surface of the orbiting-scroll base plate 6a that is located on the opposite side of a wall surface thereof at which the orbiting scroll spiral 6b is provided serves as the thrust bearing surface 6d. The orbiting-scroll base plate 6a includes a hollow cylindrical boss Sc formed at a central portion of the surface of the orbiting-scroll base plate 6a (a lower surface in Fig. 1) that is located on the opposite side of the surface thereof at which the orbiting scroll spiral 6b is provided. An eccentric shaft portion 21a provided at an upper end of the main shaft 21 is inserted in the boss 6c. When the main shaft 21 rotates, the orbiting scroll 6 makes orbital motion on a thrust surface of the frame 7.

[0020] The orbiting scroll spiral 6b compresses together with the fixed scroll spiral 5b of the fixed scroll 5, the refrigerant. Furthermore, the orbiting scroll spiral 6b defines together with the orbiting-scroll base plate 6a and the fixed scroll 5, the compression chamber 27. Furthermore, the orbiting scroll spiral 6b forms together with the frame 7 and the fixed scroll 5, the suction portion 35. The cross section of the orbiting scroll spiral 6b is spiral.

[0021] (Rotation driving unit 11) The rotation driving unit 11 is provided in the sealed container 4, and rotates the main shaft 21 to drive the compression unit 8. The rotation driving unit 11 includes a stator 9 fixed to the inner circumferential surface of the middle shell 1, and a rotor 10 provided on an inner circumferential side of the stator 9. The stator 9 is formed by winding a plurality of phases of wires around a laminated core. The rotor 10 includes therein a permanent magnet not illustrated. Furthermore, the main shaft 21 is fixed to the rotor 10 and transmits a rotational drive force of the rotation driving unit 11 to the orbiting scroll 6. That is, when power is supplied to the stator 9, the rotor 10 is rotated together with the main shaft 21. The rotation driving unit 11 can change the rotation speed of the rotor 10 by, for example, an inverter control.

[0022] (Main Shaft 21) The main shaft 21 is rotated by the rotation of the rotor 10, and transmits the rotational drive force to the orbiting scroll 6. In the main shaft 21, a main shaft portion 21b located above the rotor 10 is rotatably supported by a main bearing 22 provided at the frame 7. In the main shaft 21, a lower portion of the main shaft 21 located below the rotor 10 is rotatably supported by a sub bearing 23. As illustrated in Fig. 1, the sub bearing 23 is a ball bearing. However, the sub bearing 23 is not limited to the ball bearing, and may be another bearing. The sub bearing 23 is fitted in a sub-bearing accommodation portion fixed to a central portion of the sub frame 15 that is provided in a lower portion of the middle shell 1. An eccentric shaft portion 21a is provided at an end of the main shaft 21 on the compression unit 8 side. The eccentric shaft portion 21a is provided such that its axis is eccentric to the central axis of the main shaft 21 in a predetermined eccentric direction. Furthermore, a volumetric type of oil pump 24 that sucks up lubricant accumulated in the oil reservoir 14 is provided at a lower end of the main shaft 21. In addition, in the main shaft 21, oil holes not illustrated are provided along the central axis of the main shaft 21. The lubricant sucked up by the oil pump 24 is supplied to sliding portions through the oil holes formed in the main shaft 21.

[0023] In the scroll compressor 100, a first balance weight 25 and a second balance weight 26 are provided above and below the rotor 10 of the main shaft 21, respectively. The first balance weight 25 is fixed to an upper portion of the main shaft 21 by shrink fit, and the second balance weight 26 is fixed to a lower portion of the rotor 10. The first balance weight 25 and the second balance weight 26 are provided to offset imbalance that occurs due to the orbital motion of the orbiting scroll 6 provided at the eccentric shaft portion 21a, and to keep the balance of the entire rotation system.

[0024] [Description of Operation of Scroll Compressor 100] Next, an operation of the scroll compressor 100 will be described. When current flows through a wire portion of the stator 9, a magnetic field is produced at the stator 9. This magnetic field rotates the rotor 10. To be more specific, torque is produced at the stator 9 and the rotor 10, and the rotor 10 rotates. It should be noted that the rotor 10 is supported indirectly by the main bearing 22 and the sub bearing 23 such that the rotor is rotatable; that is, the rotor 10 is rotatably attached to the main shaft 21 supported by the main bearing 22 and the sub bearing 23. When the rotor 10 rotates, the main shaft 21 fixed to the rotor 10 also rotates. When the main shaft 21 rotates, the boss Sc of the orbiting scroll 6 is driven by the eccentric shaft portion 21a of the main shaft 21 and the orbiting scroll 6 makes orbital motion while being prevented from rotating around the axis of the orbiting scroll 6 by the Oldham ring 19.

[0025] In the scroll compressor 100, when the rotor 10 rotates, the first balance weight 25 and the second balance weight 26 keep static and dynamic balances to an eccentric revolution motion of the orbiting scroll 6. Thereby, in the scroll compressor 100, the orbiting scroll 6 eccentrically supported by the upper portion of the main shaft 21 and prevented from rotating around its axis by the Oldham ring 19 starts making orbital motion, and compresses the refrigerant in a known compression principle.

[0026] In the scroll compressor 100, part of the refrigerant gas flows into the suction portion 35 through the refrigerant suction passage 29 of the frame 7, and the refrigerant gas in the suction portion 35 is guided into the compression chamber 27 by the orbital motion of the orbiting scroll 6. Furthermore, the remaining part of the refrigerant gas passes through a cutout (not illustrated) formed in a steel plate of the stator 9, and cools an electric rotating machine and the lubricant. In the scroll compressor 100, the volume of the compression chamber 27 provided between the fixed scroll spiral 5b of the fixed scroll 5 and the orbiting scroll spiral 6b of the orbiting scroll 6 varies. The gas refrigerant that is sucked from the suction pipe 12 into the sealed container 4 by the orbital motion of the orbiting scroll 6 is sucked into the compression chamber 27 between both the spirals of the fixed scroll 5 and orbiting scroll 6, and is then compressed. By the orbital motion of the orbiting scroll 6, the compression chamber 27 is moved to the center of the orbiting scroll 6, and the volume of the compression chamber 27 is further reduced. In this step, the refrigerant gas sucked into the compression chamber 27 is compressed. The compressed refrigerant passes through the discharge port 16 of the fixed scroll 5, and pushes and opens the discharge valve 18 to flow into the high-pressure space 17. The refrigerant gas that has flowed into the high-pressure space 17 passes through the discharge pipe 13, and is discharged to the outside of the sealed container 4.

[0027] The thrust bearing load produced by the pressure of the refrigerant gas in the compression chamber 27 is received by the frame 7 that supports the thrust bearing surface 6d of the orbiting scroll 6. Furthermore, a centrifugal force and a refrigerant gas load that are produced at the first balance weight 25 and the second balance weight 26 by the rotation of the main shaft 21 are received by the main bearing 22 and the sub bearing 23. It should be noted that the low-pressure refrigerant gas in the low-pressure space 28 and the high-pressure refrigerant gas in the high-pressure space 17 are isolated from each other by the fixed scroll 5 and the frame 7, and the air tightness is maintained. When the supply of power to the stator 9 is stopped, the operation of the scroll compressor 100 stops.

[0028] Fig. 3 is a schematic vertical sectional view of the compressor that illustrates the flow of the refrigerant injected from the injection pipe 20 of the scroll compressor 100 according to Embodiment 1 of the present disclosure. Arrows in Fig. 3 indicate the flows of the two-phase refrigerant including the liquid refrigerant or the low-temperature liquid refrigerant that is injected from the injection pipe 20. In the scroll compressor 100, the inlet 29A of the at least one refrigerant suction passage 29 and the outlet 20A of the injection pipe 20 are arranged in the same straight line in the radial direction of the sealed container 4 from the central axis 0 of the sealed container 4 toward the middle shell 1, as viewed in plan view. Furthermore, the outlet 20A of the injection pipe 20 is provided in part of the middle shell 1 that is located between the compression unit 8 and the rotation driving unit 11 and closer to the compression unit 8. Thus, most of the liquid refrigerant or the two-phase refrigerant that is injected from the injection pipe 20 passes through the inlet 29A and the refrigerant suction passage 29 and flows into a compression space of the compression unit 8 as indicated by the arrows in Fig. 3.

[0029] As described above, in the scroll compressor 100, the refrigerant suction passage 29 is provided in the frame 7 to guide the refrigerant injected from the injection pipe 20 to the suction portion 35 of the compression unit 8. Thus, the liquid refrigerant or the two-phase refrigerant that is injected from the injection pipe 20 is guided into the compression unit 8 through the refrigerant suction passage 29 provided in the frame 7.

As a result, the scroll compressor 100 can reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss.

[0030] Furthermore, in the scroll compressor 100, the outlet 20A of the injection pipe 20 is provided in part of the circumferential surface of the middle shell that is located between the compression unit 8 and the rotation driving unit 11 and closer to the compression unit 8. In addition, in the scroll compressor 100, the inlet 29A of the at least one refrigerant suction passage 29 and the outlet 20A of the injection pipe 20 are arranged in the same straight line from the central axis 0 of the sealed container 4 toward the middle shell 1 in the radial direction of the sealed container 4, as viewed in plan view. Thus, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A provided in a lower portion of the frame 7, and then flows into the compressor chamber 27 through the refrigerant suction passage 29. As a result, the scroll compressor 100 can reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, most of the refrigerant injected from the injection pipe 20 does not flow through the rotation driving unit 11, and can thus reach the compression chamber 27 without absorbing heat. As a result, the scroll compressor 100 can maintain the temperature of the refrigerant to be injected, and can reduce the degree to which the discharge temperature of the compressor rises.

[0031] Furthermore, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A provided in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Thus, in the scroll compressor 100, it is possible to reduce the degree of dilution of the refrigerating machine oil stored in the oil reservoir 14, and thus also ensure the reliability of the sliding portions of the compressor.

[0032] In addition, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A provided in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29, thereby reducing the degree to which the discharge temperature of the compressor rises. Thus, in the scroll compressor 100, the fixed roll 5 does not need to have an injection port or a pipe for use in guiding the refrigerant to the port in the fixed scroll 5. Therefore, the manufacturing cost can be reduced.

[0033] Fig. 4 is an enlarged schematic vertical sectional view of a portion B of a modification of the scroll compressor 100 according to Embodiment 1 of the present disclosure as illustrated in Fig. 1. In a scroll compressor 100 of the modification, the injection pipe 20 is connected to the middle shell 1 in such a manner as to extend diagonally to the vertical direction, and an extension line of a center line L1 that extends from the outlet 20A of the injection pipe 20 passes through the inlet 29A of the refrigerant suction passage 29. The injection pipe 20 is shaped in such a manner to allow refrigerant to flow out from the outlet 20A of the injection pipe 20 toward the inlet 29A of the refrigerant suction passage 29. In the scroll compressor 100, the extension line of the center line L1 of the pipe, which extends from the outlet 20A of the injection pipe 20, passes through the inlet 29A of the refrigerant suction passage 29. Thus, the amount of liquid refrigerant that flows from the injection pipe 20 into the refrigerant suction passage 29 is larger than in the case where the above configuration is not provided. Therefore, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A provided in the lower portion of a frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. As a result, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss.

Also, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and also reduce the degree of the temperature rise of the injected refrigerant.

[0034] Fig. 5 is an enlarged schematic vertical sectional view of a portion B of another modification of the scroll compressor 100 according to Embodiment 1 of the present disclosure as illustrated in Fig. 1. In the scroll compressor 100 of the other modification, a distal end portion 20B of the injection pipe 20 is bent in the sealed container 4, and the outlet 20A of the injection pipe 20 is located to face the inlet 29A of the refrigerant suction passage 29. The injection pipe 20 is shaped in such a manner as to cause refrigerant to flow out from the outlet 20A of the injection pipe 20 toward the inlet 29A of the refrigerant suction passage 29. In the scroll compressor 100, since the outlet 20A of the injection pipe 20 faces the inlet 29A of the refrigerant suction passage 29, the amount of liquid refrigerant that flows from the injection pipe 20 into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Therefore, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A provided in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. As a result, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and can reduce the degree of the temperature rise of the injected refrigerant.

[0035] Embodiment 2 Fig. 6 is a schematic vertical sectional view of a scroll compressor 100 according to Embodiment 2 of the present disclosure. Fig. 7 is a schematic vertical sectional view of the scroll compressor 100 that is taken along line C-C in Fig. 6. Components of the scroll compressor 100 that have the same configurations as those of the scroll compressor 100 as illustrated in Figs. 1 to 5 are denoted by the same reference signs, and their descriptions will thus be omitted. In the scroll compressor 100 according to Embodiment 2 of the present disclosure, a connection position of an injection pipe 20D is different from that of the injection pipe 20 of the scroll compressor 100 of Embodiment 1. The scroll compressor 100 according to Embodiment 2 includes the frame 7 and the suction pipe 12A. The frame 7 is fixed to the sealed container 4 to accommodate the compression unit 8, and the suction pipe 12A is connected to the circumferential wall of the sealed container 4 and allows liquid refrigerant or two-phase refrigerant to be injected into the sealed container 4.

[0036] In the scroll compressor 100 according to Embodiment 2, the injection pipe 20D is connected to the suction pipe 12A. The suction pipe 12A allows the refrigerant to be sucked from the outside of the sealed container 4 into the compression unit 8. The suction pipe 12A is connected to the side wall of the middle shell 1 of the sealed container 4, and the suction pipe 12A communicates with the low-pressure space 28 in the sealed container 4 that is located between the frame 7 and the rotation driving unit 11. The injection pipe 20D connected to the suction pipe 12A allows liquid refrigerant or two-phase refrigerant to be injected into the suction pipe 12A. That is, the injection pipe 20D allows low-temperature liquid refrigerant or two-phase refrigerant including the liquid refrigerant to be injected from the injection pipe 20D into the sealed container 4 through the suction pipe 12A. Thus, through the suction pipe 12A, the low-temperature liquid refrigerant or the two-phase refrigerant including the liquid refrigerant is injected into the sealed container 4. In the scroll compressor 100 according to Embodiment 2, as illustrated in Fig. 7, the inlet 29A of the refrigerant suction passage 29 is located between the central axis 0 of the sealed container 4 and the suction pipe 12A as viewed in plan view. That is, in the scroll compressor 100, the inlet 29A of the at least one refrigerant suction passage 29 and the outlet 12B of the suction pipe 12A are located in the same straight line from the central axis 0 of the sealed container 4 toward the middle shell 1 in the radial direction of the sealed container 4, as viewed in plan view. Furthermore, re-referring to Fig. 6, the outlet 12B of the suction pipe 12A is provided in part of the middle shell 1 that is located between the compression unit 8 and the rotation driving unit 11 and closer to the compression unit 8.

[0037] As described above, in the scroll compressor 100, the refrigerant suction passage 29 is provided in the frame 7 to guide the refrigerant injected from the injection pipe 20D to the suction portion 35 of the compression unit 8. Thus, the liquid refrigerant or the two-phase refrigerant injected from the injection pipe 20D is guided into the compression unit 8 through the refrigerant suction passage 29 provided in the frame 7. Thus, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss.

[0038] Furthermore, in the scroll compressor 100 according to Embodiment 2, the outlet 12B of the suction pipe 12A is provided in part of the circumferential wall that is located between the compression unit 8 and the rotation driving unit 11 and closer to the compression unit 8. In addition, in the scroll compressor 100, the inlet 29A of the at least one refrigerant suction passage 29 and the outlet 12B of the suction pipe 12A are located in the same straight line from the central axis 0 of the sealed container 4 toward the middle shell 1 in the radial direction of the sealed container 4, as viewed in the plan view. Thus, in the scroll compressor 100, after flowing out from the outlet 12B of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss.

[0039] Furthermore, in the scroll compressor 100 according to Embodiment 2, the inlet 29A of the at least one refrigerant suction passage 29 and the outlet 123 of the suction pipe 12A are provided in the same straight line from the central axis 0 of the sealed container 4 toward the middle shell 1 in the radial direction of the sealed container 4, as viewed in plan view. Thus, in the scroll compressor 100, after flowing out of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20D does not flow through the rotation driving unit 11, and can thus reach the compression chamber 27 without absorbing heat. Accordingly, in the scroll compressor 100 according to Embodiment 2, it is possible to maintain the temperature of the refrigerant to be injected, and thus reduce the degree to which the discharge temperature of the compressor rises.

[0040] Furthermore, in the scroll compressor 100 according to Embodiment 2, after flowing out of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil stored in the lower portion of the sealed container 4, and maintain the reliability of the sliding portion of the compressor.

[0041] In addition, in the scroll compressor 100 according to Embodiment 2, after flowing out of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29, thereby reducing the degree to which the discharge temperature of the compressor rises. Therefore, in the scroll compressor 100 according to Embodiment 2, it is not necessary to provide an injection port in the fixed scroll 5 or a pipe that allows the refrigerant to flow to the port. Thus, the manufacturing cost can be reduced. Furthermore, in the scroll compressor 100 according to Embodiment 2, the number of pipes to be fixed to the middle shell 1 is one, and the manufacturing cost can thus be reduced.

[0042] Fig. 8 is an enlarged schematic vertical sectional view of a modification of the scroll compressor 100 according to Embodiment 2 of the present disclosure as illustrated in Fig. 6. It should be noted that in the scroll compressor 100 of the modification of Embodiment 1, the injection pipe 20 is connected to the middle shell 1 in such a manner as to extend diagonally to the vertical direction. Similarly, in the scroll compressor 100 according to Embodiment 2, the suction pipe 12A may be connected to the middle shell 1 diagonally to the vertical direction. In this case, an extension line of a center line L2 of a pipe that extends from the outlet 12B of the suction pipe 12A passes through the inlet 29A of the refrigerant suction passage 29. The suction pipe 12A is shaped in such a manner as to cause the refrigerant to flow out from the outlet 12B of the suction pipe 12A toward the inlet 29A of the refrigerant suction passage 29. In the scroll compressor 100, the extension line of the center line L2 of the pipe, which extends from the outlet 12B of the suction pipe 12A, passes through the inlet 29A of the refrigerant suction passage 29. Thus, the amount of liquid refrigerant or two-phase refrigerant that flows into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Thus, in the scroll compressor 100, after flowing out of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Therefore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and also can reduce the degree of the temperature rise of the injected refrigerant.

[0043] Fig. 9 is an enlarged schematic vertical sectional view of another modification of the scroll compressor 100 according to Embodiment 2 of the present disclosure as illustrated in Fig. 6. Furthermore, in the scroll compressor 100 of the other modification of Embodiment 1, the distal end portion 20B of the injection pipe 20 is bent in the sealed container 4, and the outlet 20A of the injection pipe 20 is located to face the inlet 29A of the refrigerant suction passage 29. Similarly, in the scroll compressor 100 of Embodiment 2, a distal end portion 12C of the suction pipe 12A may be bent in the sealed container 4, and the outlet 12B of the suction pipe 12A may be provided to face the inlet 29A of the refrigerant suction passage 29. The suction pipe 12A is shaped in such a manner as to cause the refrigerant to flow out from the outlet 12B of the suction pipe 12A toward the inlet 29A of the refrigerant suction passage 29. In the scroll compressor 100, since the outlet 12B of the suction pipe 12A is provided opposite to the inlet 29A of the refrigerant suction passage 29, the amount of liquid refrigerant or two-phase refrigerant that flows from the suction pipe 12A into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Therefore, in the scroll compressor 100, after flowing out of the suction pipe 12A, most of the refrigerant injected from the injection pipe 20D flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Thus, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and reduce the degree of the temperature rise of the injected refrigerant.

[0044] Embodiment 3 Fig. 10 is a schematic vertical sectional view of a scroll compressor 100 according to Embodiment 3 of the present disclosure. Fig. 11 is an enlarged schematic vertical sectional view of a portion D of the scroll compressor 100 as illustrated in Fig. 10. Fig. 12 is a schematic cross sectional view of the scroll compressor 100 that is taken along line E-E in Fig. 11. Components that have the same configurations as those of the scroll compressor 100 as illustrated in each of Figs. 1 to 9 will be denoted by the same reference signs, and their descriptions will thus be omitted. In the scroll compressor 100 according to Embodiment 3 of the present disclosure, an introduction member 30 is provided on the inner peripheral wall of the middle shell 1, in which the outlet 20A of the injection pipe 20 is located. In this regard, the scroll compressor 100 according to Embodiment 3 of the present disclosure is different from the scroll compressors 100 according to Embodiments 1 and 2.

[0045] The introduction member 30 is provided in such a manner as to face the outlet 20A of the injection pipe 20 and the inlet 29A of the refrigerant suction passage 29, and has a bottom portion 30A and a side surface 30B that define a cylindrical space. In a region where the introduction member 30 is provided, the outlet 20A of the injection pipe and the inlet 29A of the refrigerant suction passage 29 are located. The introduction member 30 serves as a duct that guides to the refrigerant suction passage 29, refrigerant that has flowed out from the outlet 20A of the injection pipe 20. The introduction member 30 is fixed to the inner peripheral wall of the middle shell 1, and provided such that the outlet 20A faces the introduction member 30. In the introduction member 30, the bottom portion 30A and the side surface 30B define the cylindrical space. In an upper portion of the introduction member 30, an opening port 300 is formed. The opening port 30D in the upper portion of the introduction member 30 is located to face the inlet 29A of the refrigerant suction passage 29. The bottom portion 30A is a plate-like member, and includes a lower end 30A2 fixed to part of the inner peripheral wall of the middle shell 1 that is located below the outlet 20A, and an upper end 30A1 that protrudes toward a center side of the sealed container 4 and is located above a lower edge of the outlet 20A. The side surface 30B includes a lower end 30B1 connected to a peripheral edge of the bottom portion 30A, and both side ends 30B2 fixed to the inner peripheral wall of the middle shell 1 on opposite sides of the outlet 20A in the circumferential direction of the middle shell 1. The introduction member 30 includes an upper end 30C located closer to the center side of the sealed container 4 than the refrigerant suction passage 29 in the radial direction of the sealed container 4. The introduction member 30 is formed of, for example, a sheet metal. In the introduction member 30, the bottom portion 30A and the side surface 30B may be formed as separate members, or may be formed integrally with each other.

Furthermore, as illustrated in Figs. 11 and 12, the introduction member 30 is formed by combining the bottom portion 30A and the side surface 30B, which are both flat, but for example, the bottom portion 30A and the side surface 30B may be formed integrally with each other and in the shape of a semicircular truncated cone. The introduction member 30 is fixed to the inner wall of the middle shell 1 by, for example, resistance welding.

[0046] In the scroll compressor 100 according to Embodiment 3, the introduction member 30 is located in such a manner as to face the outlet 20A of the injection pipe 20 and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 30A and the side surface 30B that define the cylindrical space. In the scroll compressor 100, the amount of liquid refrigerant that flows from the injection pipe 20 into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Thus, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and reduce the degree of the temperature rise of the injected refrigerant.

[0047] Fig. 13 is an enlarged schematic vertical sectional view of a modification of the scroll compressor 100 according to Embodiment 3 of the present disclosure as illustrated in Fig. 10. Fig. 14 is a schematic cross sectional view of the scroll compressor 100 that is taken along line F-F in Fig. 13. The modification of the scroll compressor 100 according to Embodiment 3 will be described with reference to Figs. 13 and 14. The introduction member 30 is located in such a manner as to face the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 30A and the side surface 30B that define a cylindrical space. In a region where the introduction member 30 is provided, the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29 are provided.

The introduction member 30 serves as a duct that guides, to the refrigerant suction passage 29, refrigerant that has flowed out from the outlet 12B of the suction pipe 12A. The introduction member 30 is fixed to the inner peripheral wall of the middle shell 1, and is provided in such a manner as to face the outlet 12B. In the introduction member 30, the bottom portion 30A and the side surface 30B define the cylindrical space. In the upper portion of the introduction member 30, the opening port 30D is formed. The opening port 30D of the upper portion of the introduction member 30 is provided to face the inlet 29A of the refrigerant suction passage 29. The bottom portion 30A is a platelike member, and includes the lower end 30A2 fixed to part of the inner peripheral wall of the middle shell 1 that is located below the outlet 12B, and the upper end 30A1 that protrudes toward the center side of the sealed container 4 and is located above the lower edge of the outlet 12B. The side surface 30B includes the lower end 30B1 connected to the peripheral edge of the bottom portion 30A, and the both side ends 30B2 fixed to the inner peripheral wall of the middle shell 1 on opposite sides of the outlet 20A in the circumferential direction of the middle shell 1. The introduction member 30 includes the upper end 30C provided closer to the center side of the sealed container 4 than the refrigerant suction passage 29 in the radial direction of the sealed container 4. The introduction member 30 is formed of, for example, a sheet metal. In the introduction member 30, the bottom portion 30A and the side surface 30B may be formed as separate members, or may be formed integrally with each other.

Furthermore, as illustrated in Figs. 13 and 14, the introduction member 30 is formed by combining the flat bottom portion 30A and the flat side surface 30B. However, for example, the bottom portion 30A and the side surface 30B may be formed integrally with each other and in the shape of a semi-circular truncated cone using a bent plate. The introduction member 30 is fixed to the inner wall of the middle shell 1 by, for example, resistance welding.

[0048] In the scroll compressor 100 of the modification, the introduction member 30 is provided in such a manner as to face the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 30A and the side surface 30B that define the cylindrical space. In the scroll compressor 100, the amount of liquid refrigerant that flows from the suction pipe 12A into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Thus, in the scroll compressor 100, after flowing out of the suction pipe 12A, most of the injection refrigerant flows into refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and reduce the degree of the temperature rise of the injected refrigerant.

[0049] Embodiment 4 Fig. 15 is a schematic vertical sectional view of a scroll compressor 100 according to Embodiment 4 of the present disclosure. Fig. 16 is an enlarged schematic vertical sectional view of a portion G of the scroll compressor 100 as illustrated in Fig. 15. Fig. 17 is a schematic cross sectional view of the scroll compressor 100 that is taken along line H-H in Fig. 16. Components that have the same configurations as those of each of the scroll compressors 100 as illustrated in Figs. 1 to 14 will be denoted by the same reference signs, and their descriptions will thus be omitted. In the scroll compressor 100 according to Embodiment 4 of the present disclosure, the fixing position of an introduction member 31 is different from that of the introduction member 30 of Embodiment 3. In this regard, the scroll compressor according to Embodiment 4 is different from the scroll compressor according to Embodiment 3. It should be noted that the introduction member 31 is fixed to a bottom wall 7C of the frame 7.

[0050] The introduction member 31 is provided in such a manner as to face the outlet 20A of the injection pipe 20 and the inlet 29A of the refrigerant suction passage 29, and includes a bottom portion 31A and a side surface 31B that define a cylindrical space.

In a region where the introduction member 30 is provided, the outlet 20A of the injection pipe 20 and the inlet 29A of the refrigerant suction passage 29 are provided. The introduction member 31 serves as a duct that guides, to the refrigerant suction passage 29, refrigerant that has flowed out from the outlet 20A of the injection pipe 20. The introduction member 31 is fixed to the bottom wall 7C of the frame 7, and is provided in such a manner as to face the inlet 29A of the refrigerant suction passage 29. In the introduction member 31, the bottom portion 31A and the side surface 31B define the cylindrical space, and also defines an opening port 31D in the horizontal direction. The opening port 31D provided in the introduction member 31 is located to face the outlet 20A of the injection pipe 20. The bottom portion 31A is a plate-like member, and is located below a lower edge of the outlet 20A in the vertical direction. The side surface 31B includes a lower end 31B2 connected to a peripheral edge of the bottom portion 31A, and an upper end 31C fixed to the bottom wall 7C of the frame 7. A side surface portion 31B1 of the side surface 31B that faces the outlet 20A includes the lower end 31B2, which is located close to the outer peripheral side of the sealed container 4, and the upper end 31C is located close to the center side of the sealed container 4, as viewed in plan view. In the introduction member 31, the upper end 31C of the side surface portion 31B1 is fixed at a position closer to the center side of the sealed container 4 than the refrigerant suction passage 29 in the radial direction of the sealed container 4. The introduction member 31 is formed of, for example, a sheet metal. In the introduction member 31, the bottom portion 30A and the side surface 30B may be formed as separate members, or may be formed integrally with each other. Furthermore, as illustrated in Figs. 16 and 17, the introduction member 31 is formed by combining the bottom portion 31A and the side surface 31B, which are both flat.

However, for example, the bottom portion 31A and the side surface 31B may be formed integrally formed of bent plates and formed in the shape of a semicircular truncated cone. [0051] In the scroll compressor 100 according to Embodiment 4, the introduction member 31 is provided in such a manner as to face the outlet 20A of the injection pipe and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 31A and the side surface 31B that define the cylindrical space. In the scroll compressor 100, the amount of liquid refrigerant that flows from the injection pipe 20 into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided Thus, in the scroll compressor 100, most of the refrigerant injected from the injection pipe 20 flows into the refrigerant suction passage 29 from the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and reduce the degree of the temperature rise of the injected refrigerant.

[0052] Fig. 18 is an enlarged schematic vertical sectional view of a modification of the scroll compressor 100 according to Embodiment 4 as illustrated in Fig. 15. Fig. 19 is a schematic cross sectional view of the scroll compressor 100 that is taken along line I-I in Fig. 18. The modification of the scroll compressor 100 according to Embodiment 4 will be described with reference to Figs. 18 and 19. The introduction member 31 is fixed to the bottom wall 7C of the frame 7. The introduction member 31 is provided in such a manner as to face the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 31A and the side surface 31B that define a cylindrical space. In a region where the introduction member is provided, the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29 are provided. The introduction member 31 serves as a duct that guides, to the refrigerant suction passage 29, refrigerant that has flowed out from the outlet 12B of the suction pipe 12A. The introduction member 31 is fixed to the bottom wall 7C of the frame 7, and is provided in such a manner as to face the inlet 29A of the refrigerant suction passage 29. In the introduction member 31, the bottom portion 31A and the side surface 31B define the cylindrical space, and also define an opening port 31D in the horizontal direction. The opening port 31D provided in the introduction member 31 is located to face the outlet 12B of the injection pipe 20. The bottom portion 31A is a plate-like member, and is located below the lower edge of the outlet 12B in the vertical direction. The side surface 31B includes a lower end 31B2 connected to the peripheral edge of the bottom portion 31A, and an upper end 31C fixed to the bottom wall 7C of the frame 7. A side surface portion 31B1 of the side surface 31B that faces the outlet 12B includes the lower end 31B2 located close to the outer peripheral side of the sealed container 4, and the upper end 31C is located close to the center side of the sealed container 4, as viewed in plan view. In the introduction member 31, the upper end 30C of the side surface portion 31B1 is fixed at a position closer to the center side of the sealed container 4 than the refrigerant suction passage 29 in the radial direction of the sealed container 4. The introduction member 31 is formed of, for example, a sheet metal. In the introduction member 31, the bottom portion 30A and the side surface 30B may be formed of different materials, or may be formed integrally with each other. Furthermore, as illustrated in Figs. 18 and 19, the introduction member 31 is formed by combining the bottom portion 31A and the side surface 31B, which are both flat. However, the bottom portion 31A and the side surface 31B may be integrally formed of bent plates and in the shape of a semicircular truncated cone.

[0053] In the scroll compressor 100 of the modification, the introduction member 31 is provided in such a manner as to face the outlet 12B of the suction pipe 12A and the inlet 29A of the refrigerant suction passage 29, and includes the bottom portion 31A and the side surface 31B that define the cylindrical space. In the scroll compressor 100, the amount of liquid refrigerant that flows from the suction pipe 12A into the refrigerant suction passage 29 is large, as compared with the case where the above configuration is not provided. Thus, in the scroll compressor 100, after flowing out of the suction pipe 12A, most of the injected refrigerant flows into the refrigerant suction passage 29 through the inlet 29A formed in the lower portion of the frame 7, and then flows into the compression chamber 27 through the refrigerant suction passage 29. Therefore, in the scroll compressor 100, it is possible to reduce the degree to which the discharge temperature rises, without causing a loss due to the dead volume of the compressor or a mixing loss. Furthermore, in the scroll compressor 100, it is possible to reduce the degree of dilution of refrigerating machine oil in the oil reservoir 14, and reduce the degree of the temperature rise of the injected refrigerant.

[0054] It should be noted that the embodiments of the present disclosure are not limited to Embodiments 1 to 4 as described above, and can be variously modified.

Furthermore, the side surface 30B of the introduction member 30 and the side surface 31B of the introduction member 31 are each formed in a rectangular shape as viewed in plan view, but are not limited to this shape, and may be formed, for example, in the shape of an arc as viewed in plan view. In addition, any members may be used as the introduction member 30 and the introduction member 31 as long as they can each serve as a duct that guides, to the refrigerant suction passage 29, the refrigerant that has flowed out from the outlet 20A of the injection pipe 20, and for example, they may be tubular.

Reference Signs List [0055] 1 middle shell, 2 upper shell, 3 lower shell, 4 sealed container, 5 fixed scroll, 5a fixed scroll base plate, 5b fixed scroll spiral, 6 orbiting scroll, 6a orbiting-scroll base plate, 6b orbiting scroll spiral, 6c boss, 6d thrust bearing surface, 7 frame, 7C bottom wall, 8 compression unit, 9 stator, 10 rotor, 11 rotation driving unit, 12 suction pipe, 12A suction pipe, 12B outlet, 12C distal end portion, 13 discharge pipe, 14 oil reservoir, 15 sub frame, 16 discharge port, 17 high-pressure space, 18 discharge valve, 19 Oldham ring, 20 injection pipe, 20A outlet, 20B distal end portion, 20D injection pipe, 21 main shaft, 21a eccentric shaft portion, 21b main shaft portion, 22 main bearing, 23 sub bearing, 24 oil pump, 25 first balance weight, 26 second balance weight, 27 compression chamber, 28 low-pressure space, 29 refrigerant suction passage, 29A inlet, 30 introduction member, 30A bottom portion, 30A1 upper end, 30A2 lower end, 30B side surface, 30B1 lower end, 30B2 side end, 30C upper end, 30D opening portion, 31 introduction member, 31A bottom portion, 31B side surface, 31B1 side surface portion, 31B2 lower end, 31C upper end, 31D opening port, 35 suction portion, 100 scroll compressor